Packaging container and packaging body

Abstract

To provide a packaging container having excellent shape retainability after development.SOLUTION: A packaging container 1 is formed by overlapping a first member 10 configured to be capable of forming an opening line 13 extending in one direction and a second member 20 that is softer than the first member 10 and joining a peripheral edge P in an overlapped state. The first member 10 has a base layer made of paper, and a cross-sectional area of a paper fiber contained in the base layer is 160 μm2 or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging container, more specifically, to a packaging container that can be used as a container by opening and unfolding it, and a package including the same. [Background technology]

[0002] In the field of packaging containers for storing food, attempts have been made to reduce the trouble of washing dishes by allowing the food to be eaten without transferring it to dishes, for example by using self-supporting pouches and the like. However, in the case of pouches and the like, if too much content is put inside, the content is likely to spill out when opened, so if the above-mentioned uses are intended, the filling rate must be kept low, which can increase distribution costs.

[0003] In relation to such problems, Patent Document 1 describes a packaging container configured by joining a flexible portion and a rigid portion. This packaging container can be opened by cutting the rigid portion and unfolded to deform into a shape with the rigid portion as a peripheral wall and an opening at the top. The packaging container described in Patent Document 1 has an advantage in that there is little need to suppress the filling rate because the shape changes significantly before and after deployment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 077194 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors have found that the packaging container according to Patent Document 1 has a problem in terms of shape retention after unfolding, and have completed the present invention.

[0006] An object of the present invention is to provide a packaging container that is excellent in shape retention after being unfolded, and a packaging body including the same. [Means for solving the problem]

[0007] A first aspect of the present invention is a packaging container formed by overlapping a first member configured to be capable of forming a tear line extending in one direction and a second member that is softer than the first member and joining their peripheral portions. In this packaging container, the first member has a base layer made of paper, and the cross-sectional area of ​​the paper fiber contained in the base layer is 160 μm 2 That's all.

[0008] A second aspect of the present invention is a package comprising the packaging container according to the first aspect and a content contained in the packaging container in a sealed state. Effect of the Invention

[0009] The packaging container according to the present invention is excellent in terms of shape retention after being unfolded. [Brief description of the drawings]

[0010] [Figure 1] 1 is a plan view showing a packaging container according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 2 shows the packaging container in an unfolded state. [Figure 4] FIG. 2 is a perspective view showing the unfolded form of the packaging container. [Figure 5A] 1 is an example of an enlarged image of a cross section perpendicular to the longitudinal grain of a first base material layer made of paper that constitutes the packaging container, captured by an optical microscope. [Figure 5B] 5B is a further enlarged image of region A1 in FIG. 5A. [Figure 6] FIG. 1 is a diagram showing a schematic diagram of an example of a packaging container having high shape retention (shape retention) in an unfolded state. [Figure 7]FIG. 2 is a diagram showing a schematic diagram of an example of a packaging container in an unfolded state that has low shape retention (shape retention) in the unfolded state. [Figure 8] 1 is a table showing an evaluation of shape retention in the unfolded form for the packaging containers of Examples 1 to 5 and Comparative Examples 1 to 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] An embodiment of the present invention will be described with reference to FIGS. As shown in Figs. 1 and 2, the packaging container 1 is formed by joining a sheet-like first member 10 and a sheet-like second member 20 together.

[0012] The first member 10 has a quadrangular shape in a plan view, and has higher rigidity than the second member 20. The first member 10 has a first base material layer 11 (base material layer) made of paper. The paper fibers of the first base material layer 11 extend in roughly the same direction. Note that "paper fibers" refers to cellulose fibers. In the following description, the direction in which the paper fibers extend in the first base material layer 11 may be referred to as the longitudinal grain, and the direction perpendicular to the longitudinal grain may be referred to as the transverse grain. In FIG. 1, the longitudinal grain of the first base material layer 11 runs along a side (second side S2 described below) extending in the vertical direction of the first member 10. The basis weight of the first base material layer 11 in this embodiment is 80 g / m 2 That's all.

[0013] The first member 10 of this embodiment further has an additional layer 12 superimposed on the first base layer 11. The additional layer 12 includes at least a heat seal layer. Examples of the heat seal layer include heat seal varnish (HS varnish) and polyethylene (PE). The additional layer 12 may further include an intermediate layer interposed between the first base layer 11 and the heat seal layer. The intermediate layer may be, for example, an oil-resistant layer, a water-resistant layer, or a barrier layer having barrier properties against water vapor, oxygen, etc. When the intermediate layer is a barrier layer, the preservation quality of the contents contained in the packaging container 1 can be improved. Examples of the intermediate layer include polyethylene terephthalate (PET).

[0014] The shape of the first member 10 in a plan view does not necessarily have to be a geometric rectangle. For example, there is no problem if the corners are rounded or the parts corresponding to the four sides are not perfectly straight.

[0015] In this embodiment, the cross-sectional area of ​​the paper fibers contained in the first base material layer 11 of the first member 10 is 160 μm 2 The cross-sectional area of ​​the paper fiber of the first base layer 11 is 300 μm 2 More preferably, the cross-sectional area is equal to or greater than this. Here, the cross-sectional area of ​​the paper fibers is the cross-sectional area of ​​the paper fibers 111 in a cross section perpendicular to the longitudinal grain of the first base material layer 11, as exemplified in Fig. 5. In this embodiment, the cross-sectional shape of the paper fibers 111 in the first base material layer 11 is annular with a cavity 112 in the center. The cross-sectional area of ​​the paper fibers 111 is the area excluding the cavity 112 in the center in Fig. 5.

[0016] In this embodiment, the tensile strength ratio (MD / TD) of the first member 10 including the first base material layer 11 is 1.7 or more. The tensile strength ratio of the first member 10 is more preferably 1.8 or more. Here, the tensile strength ratio of the first member 10 is the tensile strength in the direction along the longitudinal grain of the first base material layer 11 divided by the tensile strength in the direction along the transverse grain of the first base material layer 11. The specific values ​​of the cross-sectional area and tensile strength ratio of the paper fibers described above vary depending on the paper material, manufacturing process, and the like.

[0017] The shape of the second member 20 in a plan view corresponds to the shape of the first member 10 (specifically, a rectangle as shown in FIG. 1). The second member 20 is made of a synthetic resin and is configured to be more flexible than the first member 10. As shown in FIG. 2, the second member 20 has a second base material layer 21. Examples of materials for the second base material layer 21 include polyethylene terephthalate (PET), polyamide (NY), polyethylene (PE), and polypropylene (PP). The second member 20 further has an additional layer 22 superimposed on the second base layer 21. The additional layer 22 includes at least a heat seal layer. The heat seal layer of the second member 20 can be joined to the heat seal layer of the first member 10 by thermal fusion. The materials of the heat seal layers of the first and second members 10 and 20 may be the same as or different from each other.

[0018] The additional layer 22 may further include an intermediate layer interposed between the second base layer 21 and the heat seal layer. The intermediate layer may improve the preservation of the contents, for example, as a barrier layer similar to the first member 10. Instead of providing an intermediate layer, the second member 20 may be formed of a material having a barrier property against water vapor, oxygen, and the like.

[0019] The first member 10 and the second member 20 are overlapped so that their heat seal layers (additional layers 12, 22) face each other. Then, the peripheral edge portions P of the first member 10 and the second member 20 in plan view are joined by heat fusion.

[0020] As shown in FIG. 1 and FIG. 2, the packaging container 1 of this embodiment further includes a tape 30 for forming a tear line 13 on the first member 10. The tape 30 is attached to the surface of the first member 10 facing the second member 20 (the surface on the additional layer 12 side). One end of the tape 30 protrudes from the edge of the first member 10 in a plan view. The tape 30 is also joined to the peripheral portion P of the additional layer 22 (heat seal layer) of the second member 20. This maintains the hermeticity of the packaging container 1 before opening. However, due to a known easy peel treatment or the like on the additional layer 22 of the second member 20 or the tape 30, the bonding strength between the second member 20 and the tape 30 is weaker than the bonding strength between the first member 10 and the tape 30. Therefore, the tape 30 can be easily peeled off from the second member 20. In this embodiment, the tape 30 extends midway between a first side S1 (a side extending left-right in FIG. 1) of the first and second members 10, 20, which are rectangular in plan view, and parallel to a second side S2 (a side extending up-down in FIG. 1) of the first and second members 10, 20 that is perpendicular to the first side S1, i.e., extends along the vertical grain of the first base layer 11.

[0021] When food or other contents are to be placed inside the packaging container 1, a portion of the peripheral portions P of the first and second members 10, 20 are left unjoined, and the contents are filled into the packaging container 1 through the unjoined portions at a factory or in a store, and then the unjoined portions are sealed by heat fusion to create a package in which the contents are contained in the packaging container 1 in an airtight state. That is, the packaging container 1 according to this embodiment may be distributed with part of the peripheral edge P unjoined.

[0022] An example of the operation of the packaging container 1 when it is used will be described. When opening the packaging container 1, first, a tear line 13 extending in one direction is formed on the first member 10. Specifically, a user of the packaging container 1 grasps the end of the tape 30 protruding from the first and second members 10 and 20 and pulls it toward the first member 10, so that the tape 30 tears the first member 10 and separates from the second member 20. In this embodiment, the tape 30 is provided along the vertical grain of the first base material layer 11, so that the first member 10 can be easily torn by the tape 30. By tearing the first member 10 by the tape 30, a tear line 13 extending approximately parallel to the second side S2 of the rectangular packaging container 1 in a plan view is formed on the first member 10. The first member 10 is divided into two regions arranged on either side of the formed tear line 13.

[0023] When the packaging container 1 is placed on a mounting surface such as a table with the opening line 13 facing up, and the two areas of the first member 10 are unfolded so as to stand up from the mounting surface, the two areas of the first member 10 are separated at the middle of the opening line 13 as shown in Fig. 3. As a result, the packaging container 1 is transformed into a shape (hereinafter referred to as "unfolded shape") with a large opening at the top, with the two areas of the first member 10 as peripheral walls and the second member 20 as the bottom surface, as shown in Fig. 4. When the contents contained in the packaging container 1 are food, a user can use the packaging container 1 in the unfolded form as tableware to eat the contents.

[0024] The packaging container 1 according to this embodiment is easy to keep flat even when filled with contents before unfolding as shown in Figures 1 and 2, and has good transport efficiency. On the other hand, in the unfolded state shown in Figure 4, a large opening is formed at the top, so that the contents are unlikely to spill out when opened or unfolded, even if the filling rate is increased.

[0025] In the unfolded form of the packaging container 1, the vertical grain of the first base material layer 11 constituting the first member 10 extends in the circumferential direction of the peripheral wall. In addition, in the unfolded packaging container 1, the portions (hereinafter referred to as side seals P1) of the peripheral edge portions P (see FIG. 1) of the joined first and second members 10 and 20 corresponding to the two first sides S1 are folded in half at the opening lines 13. The side seals P1 form part of the peripheral wall of the packaging container 1 in the unfolded form.

[0026] In the unfolded form of the packaging container 1, as illustrated in Fig. 6, the smaller the mutual inclination angle of the two portions of the side seal P1 folded in half, the better the shape of the packaging container 1 can be maintained in the unfolded form, i.e., the higher the shape retention (hereinafter also referred to as "shape retention") of the packaging container 1 in the unfolded form. Also, as illustrated in Fig. 7, the larger the mutual inclination angle of the two portions of the side seal P1, the more difficult it becomes for the packaging container 1 to maintain its shape in the unfolded form, i.e., the lower the shape retention of the packaging container 1 in the unfolded form. Also, the heavier the weight of the contents contained in the packaging container 1, the lower the shape retention of the packaging container 1 in the unfolded form.

[0027] When the mutual inclination angle of the two portions of the side seal P1 is small, the diamond-shaped opening (see FIG. 4) in the unfolded packaging container 1 is kept large and stable. Conversely, when the mutual inclination angle of the two portions of the side seal P1 is large, it becomes difficult to maintain the shape of the diamond-shaped opening in the unfolded packaging container 1, and the size of the opening becomes small.

[0028] In the packaging container 1 of this embodiment, the cross-sectional area of ​​the paper fibers contained in the first base material layer 11 made of paper is 160 μm 2or more. In addition, the tensile strength ratio of the first member 10 including the first base material layer 11 is 1.7 or more. This makes it possible to reduce the mutual inclination angle of the two portions of the side seal P1 that is folded in half in the unfolded packaging container 1. In other words, the unfolded shape of the packaging container 1 can be stably maintained. Therefore, it is possible to provide a packaging container 1 that has excellent shape retention (shape retention) after unfolding. The packaging container 1 having the above-mentioned advantages is also suitable for use as tableware as described above.

[0029] In the packaging container 1 of this embodiment, the basis weight of the first base material layer 11 made of paper is 80 g / m 2 For this reason, the thickness of the first member 10 is relatively large, and the rigidity of the first member 10 is also relatively high. However, when the cross-sectional area of ​​the paper fiber of the first base material layer 11 is 160 μm 2 When the tensile strength ratio of the first member 10 including the first base material layer 11 is 1.7 or more, the unfolded form of the packaging container 1 can be stably maintained.

[0030] In the packaging container 1 of the present embodiment, for example, the cross-sectional area of ​​the paper fiber in the first base material layer 11 is 300 μm 2 or more, or when the tensile strength ratio of the first member 10 including the first base material layer 11 is 1.8 or more, the expanded form of the packaging container 1 can be stably maintained even if the weight of the contents contained in the packaging container 1 is large.

[0031] In the packaging container 1 of the present embodiment, the configuration that allows the opening line 13 to be formed in the first member 10 is not limited to the above-mentioned embodiment. For example, the first member 10 may be configured to be partially removable without using the tape 30 by providing a perforation in the first member 10, or the like. Also, the first member 10 may not be completely divided into two when opened. For example, if a cut or the like is provided in the first member 10 at a portion not joined to the second member 20 and the end of the tape 30 is made to protrude from this cut, or if a perforation is provided only in the area excluding the joined peripheral portion P, the two areas of the first member 10 will maintain a connected state at the peripheral portion P and will not be completely divided. Even with such a configuration, the first member 10 can be transformed into an unfolded form by folding the connected portion, so there is no problem in use. The specific structure that enables the packaging container 1 to be opened can be appropriately determined based on the airtightness, watertightness, and the like that are set according to the contents to be contained.

[0032] In this embodiment, the end of the tape 30 is made to protrude in a plan view of the packaging container 1 to make it easier to grip, but this is not essential to the present invention. For example, the end of the tape 30 located between the first member 10 and the second member 20 can be made easier to grip by making the length of the tape 30 not protrude in a plan view and making the first member 10 and the second member 20 in a non-joint state only in a partial area surrounding the end of the tape 30 and reaching the periphery of the packaging container 1.

[0033] As shown in Fig. 4, when the packaging container 1 is unfolded, the first member 10 is folded at the middle of the opening line 13. To assist this folding action, a first crease R1 (see Figs. 1 and 4) may be formed on the first member 10 of the packaging container 1 by embossing, laser processing, or the like. This allows the first member 10 to be easily folded at the first crease R1 so as to form a mountain fold when viewed from the outside of the peripheral wall when the packaging container 1 is unfolded.

[0034] 1 and 4, second creases R2 may be formed by embossing, laser processing, or the like in the vicinity of the portions of the packaging container 1 before unfolding that correspond to the two first sides S1 of the peripheral portions P of the first and second members 10 and 20 and that become the side seals P1 in the packaging container 1 in the unfolded form. The second creases R2 are formed in at least the first member 10. This allows the first member 10 to be easily folded at the second creases R2 so as to form a valley fold when viewed from the outside of the peripheral wall when the packaging container 1 shown in FIG. 4 is unfolded.

[0035] The packaging container according to the present invention will be further described using experimental examples (Examples 1 to 5 and Comparative Examples 1 to 3). The technical scope of the present invention is not limited in any way by the specific content of the experimental examples. In these experimental examples, the difference in shape retention due to the cross-sectional area (fiber cross-sectional area) of the paper fibers of the first base layer 11 made of paper and the tensile strength ratio of the first member 10 including the first base layer 11 was examined.

[0036] Example 1 As the first member 10, paper Kujira (product name, manufactured by Oji Materia Co., Ltd., basis weight: 120 g / m 2 A laminate was prepared in which a heat seal layer made of heat seal varnish (HS varnish) having a thickness of 2 μm was laminated by dry lamination on a first base layer 11 made of 100% polyester (Polyvinyl Chloride) and cut into a rectangle of a predetermined size.

[0037] As the tape 30 for forming the tear line 13 on the first member 10, a laminate was prepared in which a 30 μm-thick linear low-density polyethylene (LLDPE) film, two 12 μm-thick PET films, and a PE-based film having easy peel properties were laminated in this order by dry lamination, and cut into a strip of a predetermined width. The tape 30 was attached to the center of the width direction on the surface of the heat seal layer side of the first member 10.

[0038] As the second member 20, a laminate was prepared in which a second base layer 21 made of a 15 μm thick biaxially oriented nylon (ONY) film and a heat seal layer made of a 30 μm thick linear low density polyethylene (LLDPE) film were laminated by dry lamination, and the laminate was cut to the same shape and size as the first member 10.

[0039] The first member 10 and the second member 20 were stacked with their heat seal layers facing each other, and three sides of the peripheral portion P in a planar view, except for one of the short sides, were sealed by heat fusion to obtain the packaging container of Example 1.

[0040] In Example 1, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 525 μm 2 and the tensile strength ratio of the first member 10 is 2.4 (see FIG. 8). The cross-sectional area of ​​the paper fibers in the first base material layer 11 was obtained by the following procedure. First, the first base material layer 11 was cut into a piece measuring 10 mm in the longitudinal direction by 5 mm in the transverse direction, and embedded in a photocurable resin. Next, a block cross section was prepared perpendicular to the longitudinal direction using a microtome, and then a 500x OM field of view was photographed for each N3. Then, based on the photographed results, the area value was calculated at five points for the thick pulp wall thickness using ImageJ analysis software. The tensile strength ratio of the first member 10 was obtained by carrying out a tensile test in accordance with JIS P 8113 for each of the longitudinal and transverse grains of the first base material layer 11. Specifically, for each of the longitudinal and transverse grains, the first member 10 was cut into a test piece having a width of 15 mm, and the tensile strength of the test piece was measured at a chuck distance of 180 mm and a pulling speed of 20 mm / min.

[0041] Example 2 The packaging container of Example 2 is a Blizzard (product name, manufactured by Oji Materia Co., Ltd., basis weight: 120 g / m) in which the first base layer 11 of the first member 10 is paper. 2 ) except that the packaging container is the same as that of Example 1, including its shape and size. In Example 2, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 335 μm 2and the tensile strength ratio of the first member 10 is 1.9 (see FIG. 8). The method of obtaining the cross-sectional area and tensile strength ratio of the paper fibers is the same as in the first embodiment.

[0042] Example 3 In the packaging container of Example 3, the first base layer 11 of the first member 10 is made of the same paper as in Example 2, Blizzard (product name, manufactured by Oji Materia Co., Ltd., basis weight: 120 g / m 2 However, in Example 3, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 344 μm 2 and differs from Example 2 in that the tensile strength ratio of the first member 10 is 2.0 (see FIG. 8). The method of obtaining the cross-sectional area and tensile strength ratio of the paper fibers is the same as in Example 1. The packaging container of Example 3 is the same as the packaging container of Example 2, including the shape and size, except for the cross-sectional area of ​​the paper fibers in the first base material layer 11 and the tensile strength ratio of the first member 10 described above.

[0043] Example 4 The packaging container of Example 4 is made of a first base layer 11 of a first member 10, which is made of paper, bleached kraft paper HD (product name, manufactured by Mitsubishi Paper Mills, basis weight: 120 g / m 2 ) except that the packaging container is the same as the packaging containers of Examples 1 to 3, including the shape and size. In Example 4, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 162 μm 2 and the tensile strength ratio of the first member 10 is 1.7 (see FIG. 8). The method of obtaining the cross-sectional area and tensile strength ratio of the paper fibers is the same as in the first embodiment.

[0044] Comparative Example 1 The packaging container of Comparative Example 1 is a Nagoya Sarashi Ryuo (product name, manufactured by Daio Paper Corporation, basis weight: 120 g / m) in which the first base layer 11 of the first member 10 is paper. 2 ) except that the packaging container is the same as the packaging containers of Examples 1 to 4, including the shape and size. In Comparative Example 1, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 104 μm 2and the tensile strength ratio of the first member 10 is 1.6 (see FIG. 8). The method of obtaining the cross-sectional area and tensile strength ratio of the paper fibers is the same as in the first embodiment.

[0045] Comparative Example 2 The packaging container of Comparative Example 2 is the same as the packaging containers of Examples 1 to 4 and Comparative Example 1, except for the first member 10. In Comparative Example 2, the first member 10 is paper-based Ryuo Coat (product name, manufactured by Daio Paper Corporation, basis weight: 120 g / m 2 A laminate was prepared in which a heat seal layer made of a 2 μm-thick heat seal varnish (HS varnish) was laminated by dry lamination on one surface of a first base material layer 11 made of a 10 μm-thick clay coat on the other surface of the first base material layer 11, and the laminate was cut into a rectangle of a specified size. In Comparative Example 2, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 123 μm 2 and the tensile strength ratio of the first member 10 is 1.6 (see FIG. 8). The method of obtaining the cross-sectional area and tensile strength ratio of the paper fibers is the same as in the first embodiment.

[0046] Comparative Example 3 The packaging container of Comparative Example 3 is made of a paper-based Persimmon (product name, manufactured by Fuji Kako Co., Ltd., basis weight: 120 g / m) in which the first base material layer 11 of the first member 10 is paper. 2 ) except that the packaging container is the same as that of Comparative Example 2, including its shape and size. In Comparative Example 3, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 143 μm 2 and the tensile strength ratio of the first member 10 is 1.3 (see FIG. 8). The method of obtaining the cross-sectional area and tensile strength ratio of the paper fibers is the same as in the first embodiment.

[0047] Example 5 The packaging container of Example 5 is the same as the packaging containers of Examples 1 to 4 and Comparative Examples 1 to 3, except for the first member 10. In Example 5, the first member 10 is made of paper, Blizzard (product name, manufactured by Oji Materia Co., Ltd., basis weight: 120 g / m 2A laminate was prepared in which a first base layer 11 made of PET film having a thickness of 12 μm, an intermediate layer made of a PET film having a thickness of 12 μm, and a heat seal layer made of a linear low density polyethylene (LLDPE) film having a thickness of 30 μm were laminated in this order by dry lamination, and the laminate was cut into a rectangle of a specified size. In Example 5, the cross-sectional area of ​​the paper fiber in the first base layer 11, which is paper, is 323 μm 2 and the tensile strength ratio of the first member 10 is 1.8 (see FIG. 8). The method of obtaining the cross-sectional area and tensile strength ratio of the paper fibers is the same as in the first embodiment.

[0048] Using the packaging containers of Examples 1 to 5 and Comparative Examples 1 to 3, the shape retention (shape retention) of the packaging containers in the unfolded state was examined by the following procedure.

[0049] First, a first crease R1 and a second crease R2 (see FIG. 1) were formed in the first member 10 of the packaging container of each example. Next, the contents were filled from the open side (short side) of the peripheral portion P of the packaging container of each example, and the open side was then sealed by heat sealing. Two types of contents were prepared for the packaging container of each example: light weight (40 g lettuce) and medium weight (100 g cooked rice), and a light weight filled container and a medium weight filled container were produced for each example.

[0050] The packaging container of each example was placed on a mounting surface such as a table with the first member 10 facing up, and the first member 10 was torn with the tape 30 to form a tear line 13 in the first member 10, thereby opening the packaging container of each example. Next, as viewed from the first member 10 side, a mountain fold was made along the first line R1, and a valley fold was made along the second line R2. Thereafter, the two regions of the first member 10 were unfolded so as to rise up from the mounting surface, thereby forming the packaging container of each example in an unfolded form.

[0051] The shape retention of each example of the packaging container in the unfolded form was evaluated on the following three-point scale for two types of filled containers, light and medium weight. ◯: The opening is maintained in a diamond shape, the two portions of the side seal P1 are approximately parallel, and the inclination angle of these two portions is approximately zero (see FIG. 6). △: Compared to the "◯" state, the two portions of the side seal P1 are inclined toward each other, but the inclination angle of these two portions is small, and there is no significant change in the diamond shape of the opening. ×: Compared with the "◯" and "Δ" conditions, the inclination angle of two portions of the side seal P1 is large (see FIG. 7), and the diamond shape of the opening has changed significantly.

[0052] In a packaging container in an expanded form with a shape retention rating of "○", the expanded form of the packaging container is stably maintained, meaning that the shape retention of the expanded form of the packaging container is high. In a packaging container in an expanded form with a shape retention rating of "△", the expanded form of the packaging container is slightly distorted from the "○" state, meaning that the shape retention of the expanded form of the packaging container is slightly lower than that of the "○" state. In a packaging container in an expanded form with a shape retention rating of "×", the expanded form of the packaging container is significantly distorted from the "○" state, meaning that the shape retention of the expanded form of the packaging container is significantly lower than that of the "○" state. In this specification, a packaging container with a shape retention rating of "◯" is deemed to pass, and a packaging container with a shape retention rating of "Δ" or "×" is deemed to fail.

[0053] FIG. 8 shows the results of evaluating the shape retention of the packaging containers for Examples 1 to 5 and Comparative Examples 1 to 3. 8, in Comparative Examples 1 to 3, the shape retention of the packaging containers was evaluated as "x" or "Δ" (i.e., failing) for both the light-weight and medium-weight filled containers. In Example 4, the shape retention of the packaging containers was evaluated as "x" (i.e., failing) for the medium-weight filled containers. In contrast, in Examples 1 to 5, the shape retention of the packaging containers for the light-weight filled containers was "○" (i.e., passed). Also, in Examples 1 to 3 and 5, the shape retention of the packaging containers for the medium-weight filled containers was "○" (i.e., passed).

[0054] From the above, when the contents to be contained in the packaging container are light (40 g), the cross-sectional area of ​​the paper fiber in the first base material layer 11 is 160 μm 2 It was also revealed that the tensile strength ratio of the first member 10 being 1.7 or more allows the packaging container to stably maintain its unfolded shape. In addition, when the content contained in the packaging container is of a medium weight (100 g), the cross-sectional area of ​​the paper fiber in the first base layer 11 is 300 μm 2 As described above, it was also made clear that when the tensile strength ratio of the first member 10 is 1.8 or more, the unfolded form of the packaging container can be stably maintained.

[0055] Although one embodiment of the present invention has been described, the specific configuration is not limited to this embodiment, and configuration changes and combinations within the scope of the gist of the present invention are also included. Some modifications are exemplified below, but these are not all inclusive, and other modifications are also possible. Two or more of these modifications may be appropriately combined.

[0056] The first member 10 and the second member 20 do not need to be completely the same shape and size. For example, the first member 10 may be slightly larger than the second member 20.

[0057] There is no particular limit to the contents contained in the packaging container 1, and it can be used to store a wide variety of items, not just food. There is no particular limit to the form of the contents, and by appropriately changing the configuration of the first member 10, in addition to powder and granules, it can accommodate any form of contents, such as liquid and gel.

[0058] The packaging container 1 according to the present invention may be distributed without any contents. By distributing it in such a form, it can be used as a container for eating and drinking outdoors. [Explanation of symbols]

[0059] 1 Packaging container 10 First member 11 First base material layer (base material layer) 13 Opening Line 20 Second member 111 Paper Fibers 112 Cavity P periphery

Claims

1. A packaging container formed by joining peripheral portions of a first member configured to be able to form a tear line extending in one direction and a second member that is softer than the first member in a stacked state, The first member has a base layer made of paper, The cross-sectional area of ​​the paper fiber contained in the base layer is 160 μm ２ The packaging container described above.

2. The cross-sectional area of ​​the paper fiber is 300 μm ２ The packaging container according to claim 1 .

3. 3. The packaging container according to claim 1, wherein the cross-sectional shape of the paper fibers is annular with a cavity in the center.

4. A packaging container formed by joining peripheral portions of a first member configured to be able to form a tear line extending in one direction and a second member that is softer than the first member in a stacked state, The first member has a base layer made of paper, A packaging container, wherein the first member has a tensile strength ratio of 1.7 or more.

5. The packaging container according to claim 4, wherein the first member has a tensile strength ratio of 1.8 or more.

6. The basis weight of the base layer is 80 g / m ２ The packaging container according to claim 1 or 2.

7. The packaging container according to claim 1 or 2, A content contained in the packaging container in a sealed state; A packaging body comprising:

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