Packaging container and its manufacturing method

Abstract

A packaging container (1) that can stand stably is provided. The packaging container (1) comprises a laminated sheet (2) in which at least a substrate (2A), a barrier layer (2B), and a sealant layer (2C) are laminated in this order, and the stiffness of the laminated sheet (2) measured by the Taber stiffness tester method in accordance with JIS-P8125 is 1.01 [mN m] or less.

Description

[Technical Field]

[0001] The present invention relates to a packaging container and a manufacturing method thereof, and more particularly to a packaging container for storing food and drink such as retort pouch foods and beverages, and a technology that is effective when applied to a manufacturing method thereof. [Background technology]

[0002] Canned or bottled foods, as well as retort pouches made of laminated sheets in which aluminum foil is sandwiched between various plastic films, have traditionally been used as packaging containers for ready meals that can be stored for a long period of time, such as baby food, nursing care food, and stewed dishes such as curry and fish. In recent years, many retort pouches have been distributed that use alumina or silica-deposited films that can be used in microwave ovens as the base material for the laminated sheet (see Patent Document 1). Retort pouches such as those in Patent Document 1 are advantageous as an alternative to cans and bottles from an environmental perspective, in terms of transportation costs and ease of disposal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4232246 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in recent years, with the rise in awareness of disaster prevention, the ability to eat and drink directly from the storage container has become an important function as a stockpile of food for emergencies. However, according to the investigations of the present inventors, when a plastic film is used as the substrate as in Patent Document 1, the substrate may have a weak rigidity, and there is room for improvement in its application as a packaging container that can stand stably in the palm of one's hand. Although the rigidity can be increased by increasing the thickness of the plastic film substrate, this makes disposal more difficult and places a greater burden on the environment.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a packaging container that can stand stably and independently, and a method for manufacturing the same. [Means for solving the problem]

[0006] In order to achieve the above object, a packaging container according to one embodiment of the present invention comprises a laminated sheet in which at least a substrate, a barrier layer, and a sealant layer are laminated in this order, and has a stiffness (rigidity) of 1.01 mN·m or less as measured by the Taber stiffness tester method in accordance with JIS-P8125.

[0007] Further, a method for manufacturing a packaging container according to one aspect of the present invention includes the steps of: preparing a laminated sheet in which a substrate, a barrier layer, and a sealant layer are laminated in this order, the laminated sheet being formed in a rectangular shape having a first direction and a second direction perpendicular to each other, and the laminated sheet being divided in this order along the first direction into a front surface, a first portion and a second portion of a bottom surface, and a back surface; folding the laminated sheet in two so that the sealant layers face each other and the first and second portions of the front and back surfaces and the bottom surface overlap each other; a step of forming a cutout portion by removing a part of each of the first part and the second part at each edge on both sides in the second direction of the first part and the second part of the bottom surface portion while the first part and the second part are overlapped; folding the first and second parts between the front and back parts so that the cutouts of the first and second parts face each other and overlap each other; and a sealing step of sealing the sealant layers of the front and back portions to each other at the edges on both sides in the second direction of the front and back portions, the sealant layers of the first parts of the front and bottom portions to each other, the sealant layers of the second parts of the front and bottom portions to each other, and the sealant layers of the front and back portions to each other through the cut-outs in the first and second parts. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a packaging container that can stand stably and independently, and a method for manufacturing the same. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing the cross-sectional structure of a laminated sheet used in a packaging container according to a first embodiment of the present invention. [Figure 2] 1 is a front view showing the front side of a packaging container according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a rear view showing the rear side opposite to the front side of the packaging container according to the first embodiment of the present invention. [Figure 4] FIG. 1 is a perspective view showing a method for assembling a packaging container according to a first embodiment of the present invention. [Figure 5] FIG. 3 is a cross-sectional view showing a cross-sectional structure taken along line II-II in FIG. [Figure 6] FIG. 3 is a cross-sectional view showing a cross-sectional structure taken along line III-III in FIG. 2. [Figure 7] 1A to 1C are diagrams illustrating a method for manufacturing a packaging container according to the first embodiment of the present invention. [Figure 8] 1A to 1C are diagrams illustrating a method for manufacturing a packaging container according to the first embodiment of the present invention. [Figure 9] FIG. 4 is a front view showing the front side of a packaging container according to a second embodiment of the present invention. [Figure 10] FIG. 10 is a front view showing a state in which the cutout area shown in FIG. 9 has been cut out. [Figure 11] FIG. 10 is a front view showing the front side of a packaging container according to a third embodiment of the present invention. [Figure 12] FIG. 12 is a front view showing a state in which the cutout area shown in FIG. 11 has been cut out. DETAILED DESCRIPTION OF THE INVENTION

[0010] A packaging container according to one embodiment of the present invention will be described below with reference to the drawings. The drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, and the like differ from the actual product. Furthermore, the embodiments shown below exemplify configurations for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited to the materials, shapes, and structures of the components described below. Various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims. In the following embodiment, as an example, a packaging container for ready meals that can be stored for a long period of time will be described.

[0011] (Embodiment 1) As shown in FIGS. 1 to 4, a packaging container 1 according to a first embodiment of the present invention is mainly composed of a laminated sheet 2. As shown in Fig. 1, the laminate sheet 2 has a laminated structure in which a base material 2A that increases the rigidity (stiffness) of the laminate sheet, a barrier layer 2B that excels in various barrier properties such as oxygen and ultraviolet rays, and a sealant layer 2C that excels in thermocompression bonding and sealing properties are laminated in this order. In this embodiment, the base material 2A has a basis weight of, for example, 60 to 140 g / m 2 A paper substrate having a thickness of 120 to 220 μm is used. The barrier layer 2B is a barrier film having a thickness of about 12 μm, formed by vapor deposition of an inorganic compound, for example. The sealant layer 2C is a non-oriented polypropylene film (CPP film) having a thickness of 70 μm or more, for example.

[0012] For example, when the oxygen permeability (oxygen transmission rate) of a plurality of laminate sheets 2 was measured at 30°C and 70% RH (relative humidity) using a MOCON OXTRAN 2 / 21ML, the values ​​were 0.01, 0.002, 0.039, and 0.014 cc / m 2 The value obtained was 1 / day / atm. This measurement method complies with the MOCON method (JIS-K7126-2:2006). Furthermore, the water vapor permeabilities of the laminated sheets 2 were measured by the cup method at 40°C and 90% RH (relative humidity), and were 0.565, 0.651, 0.929, and 0.957 g / m 2 The value obtained was 1 / day. This measurement method complies with JIS-Z0208:1976.

[0013] The packaging container 1 is formed by folding a single laminate sheet 2 into a W-shape in side view with the sealant layers 2C facing each other. That is, as shown in FIGS. 2 and 3 , the packaging container 1 includes a front portion 21 and a back portion 22 arranged opposite each other with the sealant layers 2C facing each other, and a bottom portion 23 folded inward of the front portion 21 and the back portion 22 from one end to the other end of the front portion 21 and the back portion 22 in a first direction. Each of the front portion 21 and the back portion 22 has a height in a first direction (X direction) and a width in a second direction (Y direction) perpendicular to the first direction in the same plane. In this embodiment, the first direction, the X direction, is sometimes referred to as the height direction, and the second direction, the Y direction, is sometimes referred to as the width direction. Therefore, the bottom surface portion 23 is provided on one end side (one side side) of one end side (one side side) and the other end side (the other side side) located opposite each other in the height direction (X direction) of each of the front surface portion 21 and the back surface portion 22. The bottom surface portion 23 is folded in half inside each of the front surface portion 21 and the back surface portion 22 so that the first portion 23a and the second portion 23b face each other (see FIG. 4(c)).

[0014] The packaging container 1 also has side seal portions 24 formed by doubling and sealing the widthwise edges (hereinafter sometimes simply referred to as edges) of the front portion 21 and the back portion 22, and a bottom seal portion 25 formed by doubling and sealing the widthwise edges (hereinafter sometimes simply referred to as edges) of the front portion 21 and the back portion 22 and the bottom portion 23. In Figures 2 and 3, the side seal portion 24, the bottom seal portion 25, and a reinforcing seal portion 25a (described later) are indicated by hatching. The side seal portion 24 and the bottom seal portion 25 are provided on two edges located on opposite sides in the width direction (Y direction) of the front portion 21 and the back portion 22, respectively. The bottom seal portion 25 extends from one end (one side) of the front portion 21 and the back portion 22 toward the other end (the other side), and the side seal portion 24 is connected to the bottom seal portion 25 and extends from the bottom seal portion 25 toward the other end of the front portion 21 and the back portion 22. The dimension 23h of the folded bottom depth of the bottom portion 23, in other words, the length of the bottom seal portion 25, is preferably 10 to 40% of the height dimension 1h of the front portion 21 and the back portion 22. If it is less than 10%, narrower than this range, the bottom portion 23 becomes narrow when opened, and the packaging container 1 cannot stand on its own stably. Furthermore, if it is greater than 40%, wider than this range, the folded bottom portion 23 does not open completely when opened, and the packaging container 1 cannot stand on its own stably. A more preferable range is 15 to 25%. This range further improves the self-standing ability.

[0015] The packaging container 1 also includes a reinforcing seal portion 25a formed by doubly overlapping and sealing one of the first portion 23a and the second portion 23b of the bottom portion 23 with the front portion 21, and a reinforcing seal portion 25b formed by doubly overlapping and sealing the other of the first portion 23a and the second portion 23b of the bottom portion 23 with the back portion 22. The reinforcing seal portions 25a and 25b are respectively provided on two edges located on opposite sides in the width direction of the front portion 21 and the back portion 22. The reinforcing seal portions 25a and 25b provided on one edge of the front portion 21 and the back portion 22 extend from one end side of the front portion 21 and the back portion 22 to one bottom seal portion 25 and are connected to one bottom seal portion 25. The reinforcing seal portions 25a and 25b provided on the other edge sides of the front portion 21 and the back portion 22 extend from one end side of the front portion 21 and the back portion 22 to the other bottom seal portion 25 and are connected to the other bottom seal portion 25.

[0016] The packaging container 1 is also provided with a storage section 30 that is surrounded by a front surface 21, a back surface 22, and a bottom surface 23, and is formed by sealing the front surface 21, the back surface 22, and the bottom surface 23 with a side seal section 24 and a bottom seal section 25. The side seal section 24, the bottom seal section 25, and the reinforcing seal sections 25a and 25b are formed by thermocompression bonding, ultrasonic welding, or the like. At the boundary between the bottom seal portion 25 and the side seal portion 24, a point seal portion 26 for improving sealing performance is provided across the bottom seal portion 25 and the side seal portion 24. The point seal portion 26 is preferably formed with a width that is 40 to 90% of the seal width of the bottom seal portion 25 and the side seal portion 24. The point seal portion 26 is provided on each of the two widthwise edge sides of the front portion 21 and the back portion 22.

[0017] Furthermore, it is preferable that the ratio of the length of bottom seal portion 25 in the X direction to the overall length of point seal portion 26 in the X direction extending across side seal portion 24 and bottom seal portion 25 is 10% or more. If it is less than 10%, the strength will be insufficient, and there is a high possibility that the food or drink (contents) in storage portion 30 will leak when packaging container 1 is dropped. When sealing is performed by thermocompression bonding or ultrasonic welding, the sealant layers 2C are fused together as shown in Fig. 5, so the sealing lines are not clearly visible from the outer surface of the packaging container 1 (the surface of the laminate sheet 2 on the base material 2A side). Therefore, the design of the outer surface of the packaging container 1 is not impaired.

[0018] As shown in FIGS. 2 and 3, each of the two bottom seal portions 25 has a cutout 27. As shown in FIG. 6, the bottom portion 23 requires bonding the substrates 2A together, and the cutout 27 allows the sealant layer 2C of the bottom seal portion 25 to be exposed toward the bottom portion 23. That is, the sealant layers 2C of the front portion 21 and the back portion 22 can be fused together through the cutouts 27, 27 provided in the first portion 23a and the second portion 23b of the bottom seal portion 25. The cutout 27 is preferably located 5 to 50% of the bottom fold depth (dimension 23h) from the lower end of the bottom seal portion 25. If the cutout 27 is located below this range, not only will the cutout area be insufficient, but the impact of a drop will be concentrated during a drop test, reducing the bag's breakage strength. Furthermore, if the cutout 27 is located above this range, the unsealed lower side of the bottom portion will open up due to the weight of the contents, making the bag unable to stand on its own. A more preferable range is 5 to 30%, and an even more preferable range is 10 to 20%. Within this range, both the bag breaking strength in a drop test and the self-standing stability are further improved.

[0019] In this embodiment, the cutout portion 27 is composed of a wide slit (strip-shaped cutout area) cut inward from the edge of the bottom seal portion 25 with a predetermined width, but it may also be composed of a through hole with a planar shape such as a circle or ellipse. A hermetic seal section 28 is provided on the other end of the front surface section 21 and the back surface section 22, which overlaps and seals the front surface section 21 and the back surface section 22 in two layers to hermetically seal the storage section 30 after the food has been placed in the storage section 30. In addition, at least one of the two side seal sections 24 is provided with a cutout section 29 for cutting off the upper side of the front surface section 21 and the back surface section 22 to open the upper side of the storage section when removing the food from the storage section 30 after retorting (heat treatment).

[0020] As shown in FIGS. 4(a) and 4(b), the packaging container 1 configured in this manner is defined in the longitudinal direction of the packaging container 1 in a sheet state by a front surface portion 21, a bottom surface portion 23 (first portion 23a, second portion 23b), and a back surface portion 22, in this order. Next, bottom seal portions 25, 25 are provided at both ends of the width direction (second direction) of each of the first portion 23a and the second portion 23b. Furthermore, side seal portions 24 and bottom seal portions 25 are provided at both ends of the width direction of each of the front surface portion 21 and the back surface portion 22. Of these, the side seal portions 24 are provided so as to be located at both ends of the longitudinal direction (first direction) of the packaging container 1 in a sheet state. That is, the side seal portions 24, bottom seal portion 25, bottom seal portion 25, bottom seal portion 25, bottom seal portion 25, side seal portions 24 are provided in this order along the longitudinal direction of the packaging container 1 in a sheet state.

[0021] The longitudinal dimension (first direction) of the bottom seal portion 25 is set to be approximately equal to the dimensions of the first portion 23a and the second portion 23b along the longitudinal direction (first direction) of the packaging container 1 in a sheet state. It is preferable that the longitudinal dimension (first direction) of the bottom seal portion 25 provided on the front portion 21 and the back portion 22 is approximately equal to the longitudinal dimension (first direction) of the bottom seal portion 25 provided on the bottom portion 23. Next, as shown in Figure 4(b), the first part 23a and the second part 23b are mountain-folded, and the front part 21 or the back part 22 and the bottom part 23 are valley-folded, and the sheet-like packaging container 1 is folded so that the front part 21 and the back part 22 face each other in a W-shape when viewed from the side.

[0022] Next, as shown in FIG. 4(c), the side seal portions 24, 24 at one widthwise end of the packaging container 1 are tightly attached to each other, and the bottom seal portion 25 of the front portion 21 or the back portion 22 is tightly attached to the bottom seal portion 25 of the bottom portion 23, and are secured together by, for example, thermocompression or ultrasonic welding. The side seal portion 24 and the bottom seal portion 25 at the other widthwise end of the packaging container 1 are then secured in the same manner, resulting in a packaging container 1 as shown in FIG. 4(d). This packaging container 1 is bag-shaped and has a storage section 30 with openings at both ends of the packaging container 1 in the longitudinal direction (first direction) in a sheet state. Then, as shown in FIG. 4(e), the openings of the packaging container 1 are expanded, and the first and second portions 23a, 23b are pressed from within the storage section 30, so that most of the first and second portions 23a, 23b come into contact with the surface on which the packaging container 1 is placed, helping the packaging container 1 to stand upright. After the food is placed in the storage section 30 of this packaging container 1, the storage section 30 is depressurized, and then the sealing sections 28, 28 shown in Figure 4(a) are fixed together in the same manner as the side sealing section 24 and the bottom sealing section 25 to seal the container.

[0023] When the packaging container 1 is placed upright with the bottom surface 23 facing downwards while a liquid food is contained in the storage section 30, the food moves toward the bottom surface 23. The movement of the food increases the internal pressure on the bottom surface 23 side of the storage section 30, causing the bottom surface 23, which had been folded inside the front surface 21 and back surface 22, to open, and one end side (bottom surface 23 side) of the storage section 30 to expand. This allows the packaging container 1 to stand on its own with the bottom surface 23 facing downwards. In order to make the packaging container 1 stand stably, it is useful to increase the thickness of the base material 2A and increase the rigidity of the laminated sheet 2. However, if the rigidity of the laminated sheet 2 is too high, it becomes difficult to fold the bottom surface 23 in a bag-making machine. Therefore, the present inventors have studied folding in a bag making machine and found that a laminated sheet 2 having a Taber stiffness (stiffness) of 1.01 mN·m or less, as measured by a Taber stiffness tester method in accordance with JIS (Japanese Industrial Standards)-P8125:2000, can be folded in a bag making machine. Therefore, a laminated sheet 2 having a stiffness of approximately 1.01 mN·m or less can be folded in a bag making machine, making it possible to provide a packaging container 1 that can stand stably. Here, stiffness refers to what is generally called the stiffness of paper. The Taber stiffness tester method is a type of load test method.

[0024] Furthermore, the laminate sheet 2 uses a paper substrate as the substrate 2A. A paper substrate can significantly reduce the calories generated when burned when disposed of compared to plastic substrates, so a packaging container 1 made of a laminate sheet 2 using a paper substrate has a smaller environmental impact. Furthermore, since the bottom portion 23 of the packaging container 1 is folded from the front portion 21 and the back portion 22 toward the inside of the front portion 21 and the back portion 22, a seal portion that overlaps and seals the front portion 21 and the back portion 22 with the bottom portion 23 is not present at one end of the front portion 21 and the back portion 22. If a seal portion is present at one end of the front portion 21 and the back portion 22, when the packaging container is placed upright with the bottom portion 23 facing downwards, the bottom portion 23 of the packaging container 1 will be raised above the installation surface where it comes into contact with, for example, a microwave oven turntable. In other words, a portion of the bottom portion 23 will be separated (floating) from the turntable. Because microwave ovens have a high heating power on the installation surface side, a packaging container with a raised bottom portion above the installation surface will affect the heating of food. In contrast, the packaging container 1 of this embodiment 1 does not have a sealed portion on one end side of the front portion 21 and the back portion 22, and the bottom portion 23 is not raised from the installation surface, so heating in a microwave oven can be performed more efficiently than when a sealed portion is present on one end side of the front portion 21 and the back portion 22.

[0025] The packaging container 1 may use a cellulose-containing sheet as a base material, and may also use stone paper, which is primarily made from inorganic minerals, as a paper substitute, such as LIMEX, a new material made primarily from limestone and developed and manufactured by TBM Co., Ltd. Stone paper is a material made from limestone and resin. Inorganic minerals refer to natural minerals such as limestone, but also include artificial materials that are similar to or have the same properties as natural minerals, such as synthetic calcium carbonate and synthetic mica.

[0026] Materials containing cellulose include paper and materials that use paper and resin, such as paper coated with resin or resin coated with cellulose fibers. Cellulose itself is not limited to plant-derived materials such as wood and grass, but also includes cellulose-like substances derived from natural polysaccharides (such as the substance that makes up silk and the substance produced by sea squirts), cellulose or cellulose-like substances that have had substituents introduced or have had their molecular weight reduced (the molecular length shortened). Resins used in the above include thermoplastic resins (polyethylene, polypropylene, PET, polyvinyl acetate resin, acrylic resin, etc.), thermo-(photo-)setting resins (urethane, epoxy, phenolic resin, etc.), and water-soluble polymers (polyvinyl alcohol, thermoplastic resins, thermosetting resins that can be used as water-soluble dispersions).

[0027] Here, the packaging container 1 of this embodiment 1 uses a paper substrate as the substrate 2A of the laminated sheet 2. In this case, it can be heated in a microwave oven. Conventionally, a laminated sheet in which aluminum foil is sandwiched between various plastic films is known, but this cannot be heated in a microwave oven. Also known is a product that uses an alumina or silica vapor-deposited film that can be heated in a microwave oven, but this alumina or silica vapor-deposited film is thin and therefore weak, making it difficult for the packaging container to stand upright, especially in the palm of one's hand. On the other hand, the packaging container 1 of this embodiment 1 is strong, and in emergencies or disasters, it is possible to eat or drink directly from the storage container. Furthermore, since the packaging container 1 of this embodiment 1 uses a paper substrate as the substrate 2A of the laminated sheet 2, the patterns drawn on the front portion 21 and the back portion 22 do not change even after heat treatment. It is also possible to write names, text, etc. on the front portion 21 and the back portion 22. It is also environmentally friendly and does not require excessive packaging. It is also lightweight and, from an environmental perspective, is useful as a substitute for cans and bottles due to its low transportation costs and ease of disposal.

[0028] Next, the method for manufacturing the packaging container 1 according to the first embodiment of the present invention will be further described with reference to FIGS. First, a laminate sheet 2 shown in Fig. 7(a) is prepared. As shown in Fig. 1, this laminate sheet 2 has a laminated structure in which at least a base material 2A, a barrier layer 2B, and a sealant layer 2C are laminated in this order. As shown in Fig. 7(a), the laminate sheet 2 is formed in a rectangular shape having a first direction, an X direction (height direction), and a second direction, a Y direction (width direction), which are perpendicular to each other in the same plane, and is configured such that a front surface portion 21, a first portion 23a and a second portion 23b of a bottom surface portion 23, and a back surface portion 22 are defined in this order along the X direction.

[0029] Next, as shown in FIG. 7(b), the laminate sheet 2 is folded in two so that the front portion 21 and the back portion 22 and the first portion 23a and the second portion 23b of the bottom portion 23 overlap each other. The laminate sheet 2 is folded in two so that the sealant layers 2C of one half and the other half face each other, with the folding line between the first portion 23a and the second portion 23b of the bottom portion 23 as the boundary. That is, in the laminate sheet 2 folded in two, the sealant layers 2C of the front portion 21 and the back portion 22 face each other (see FIG. 5), and similarly, the sealant layers 2C of the first portion 23a and the second portion 23b of the bottom portion 23 face each other. The base material 2A of each of the front portion 21 and the back portion 22 is positioned on the outer side (see FIG. 5), and similarly, the base material 2A of each of the first portion 23a and the second portion 23b of the bottom portion 23 is positioned on the outer side.

[0030] 7(c), with the first portion 23a and the second portion 23b of the bottom surface portion 23 overlapping each other, a cutout 27 is formed by removing a portion of each of the first portion 23a and the second portion 23b from each of the edges on both sides in the Y direction of the first portion 23a and the second portion 23b. The cutout 27 is formed, for example, by performing a punching process on the first portion 23a and the second portion 23b overlapping each other. 7(d), the first portion 23a and the second portion 23b of the bottom surface portion 23 are folded between the front surface portion 21 and the back surface portion 22 so that the cutout portions 27 of the first portion 23a and the second portion 23b of the bottom surface portion 23 face each other and the first portion 23a and the second portion 23b overlap each other. In this step, the base material 2A sides of the first portion 23a and the second portion 23b of the bottom surface portion 23 face each other. The sealant layer 2C sides of the front surface portion 21 and the first portion 23a face each other, and the sealant layer 2C sides of the back surface portion 22 and the second portion 23b face each other.

[0031] Next, on both sides of the front portion 21 and the back portion 22 in the Y direction, with the first portion 23a and the second portion 23b of the bottom portion 23 overlapping each other, the sealant layers 2C of the front portion 21 and the first portion 23a are sealed together, and the sealant layers 2C of the back portion 22 and the second portion 23b are sealed together. These sealing processes are performed by, for example, thermocompression bonding or ultrasonic welding. Through this process, as shown in FIG. 8(a), a reinforcing seal portion 25a is formed by sealing the sealant layers 2C of the front portion 21 and the first portion 23a together, and a reinforcing seal portion 25b is formed by sealing the sealant layers 2C of the back portion 22 and the second portion 23b together. The reinforcing seal portions 25a are formed obliquely from both edges of the front portion 21 extending in the X direction toward the lower end 21a of the front portion 21 (the bent portion between the front portion 21 and the first portion 23a of the bottom portion 23; see FIG. 7(d)). In addition, the reinforcing seal portion 25b is also formed obliquely from both edge sides extending in the X direction of the back surface portion 22 toward the lower end 22a of the back surface portion 22 (the folded portion between the back surface portion 22 and the second portion 23b of the bottom surface portion 23, see Figure 7(d)).

[0032] Next, the sealant layers 2C are partially sealed together at both edges of the front portion 21 and the back portion 22 in the Y direction, across a double-layered region where the front portion 21 and the back portion 22 overlap, and across a quadruple-layered region where the front portion 21, the back portion 22, and the first portion 23a and the second portion 23b of the bottom portion 23 overlap. This sealing is performed by, for example, thermocompression bonding or ultrasonic welding. This process forms a point seal portion 26 where the sealant layers 2C are sealed together across the double-layered region and the quadruple-layered region, as shown in FIG. 8(b).

[0033] Next, at the edges on both sides in the Y direction of the front portion 21 and the back portion 22, the sealant layers 2C on the front portion 21 and the back portion 22 are sealed together, the sealant layers 2C on the first portions 23a of the front portion 21 and the bottom portion 23 are sealed together, the sealant layers 2C on the second portions 23b of the back portion 22 and the bottom portion 23 are sealed together, and the sealant layers 2C on the front portion 21 and the back portion 22 are sealed together through the cut-out portions 27 of the first portions 23a and the second portions 23b. These sealings are performed by, for example, thermocompression bonding or ultrasonic welding. By this process, as shown in Figure 8(c), a side seal portion 24 is formed in which the Y-direction edges of the front portion 21 and the back portion 22 are overlapped twice to seal the sealant layers 2C together, and a bottom seal portion 25 is formed in which the Y-direction edges of the first portion 23a and the second portion 23b of the front portion 21, the back portion 22, and the bottom portion 23 are overlapped four times to seal the sealant layers 2C together.

[0034] Thereafter, the laminated sheet 2 having the side seal portion 24, bottom seal portion 25, reinforcing seal portions 25a, 25b, and point seal portions formed therein is cut into a predetermined shape, thereby nearly completing the packaging container 1 shown in Figures 2 and 3. In this cutting process, a notch portion 29 is formed in the side seal portion 24. According to the method for manufacturing the packaging container 1 according to the first embodiment of the present invention, it is possible to manufacture a packaging container 1 that can stand on its own stably. Furthermore, according to the manufacturing method of the packaging container 1 of embodiment 1 of the present invention, the sealant layers 2C of the laminated sheet 2 can be sealed together in the side seal portion 24, bottom seal portion 25, reinforcing seal portions 25a, 25b and point seal portion 26, so that a packaging container 1 with excellent sealing properties can be manufactured.

[0035] In this embodiment 1, the reinforcing sealing step (see FIG. 8(a)) of forming the reinforcing seal portions 25a and 25b, the point sealing step (see FIG. 8(b)) of forming the point seal portion 26, and the side and bottom sealing step (see FIG. 8(c)) of forming the side seal portion 24 and the bottom seal portion 25 are described in this order, but the order of these sealing steps is not limited to this and may be in any order. For example, if the reinforcing sealing step shown in FIG. 8(a) is S1, the point sealing step shown in FIG. 8(b) is S2, and the side and bottom sealing step shown in FIG. 8(c) is S3, the order may be S1 → S3 → S2, S2 → S1 → S3, S2 → S3 → S1, S3 → S1 → S2, or S3 → S2 → S1. In addition, either the front portion 21 or the back portion 22 may be provided with an insertion portion that allows a straw or the like to be inserted into the storage portion 30 from the outside, or a steam exhaust portion that releases steam from within the storage portion 30 to the outside when the pressure within the storage portion 30 exceeds a certain level due to heating of the contents (food or drink) within the sealed storage portion 30.

[0036] Examples and comparative examples of this embodiment are shown below, but this embodiment is not limited to the following examples. Example 1 In Example 1, a packaging container similar to that of Embodiment 1 was produced using a laminate sheet made of the following material as the laminate sheet 2. The substrate 2A has a basis weight of 70 g / m 2 A paper substrate with a thickness of 133 μm was used. A barrier film with a thickness of 12 μm formed by vapor deposition of an inorganic compound was used as the barrier layer 2B. A non-oriented polypropylene film (CPP film) with a thickness of 70 μm was used as the sealant layer 2C. The bottom fold depth dimension 23h was set to 18% of the height dimension 1h of the packaging container 1. The packaging container of Example 1 stood upright with food contained therein and was stable.

[0037] Example 2 In Example 2, a packaging container was produced using a laminate sheet 2 made of the following material. The substrate 2A has a basis weight of 80 g / m 2 A paper substrate having a thickness of 139 μm was used. The barrier layer 2B and the sealant layer 2C were made of the same films as in Example 1. The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 2 also stood stably when it was placed upright with food inside.

[0038] Example 3 In Example 3, a packaging container was produced using a laminate sheet 2 made of the following material. The substrate 2A has a basis weight of 90 g / m 2 A paper substrate having a thickness of 146 μm was used. The barrier layer 2B and the sealant layer 2C were made of the same films as in Example 1. The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 3 also stood stably when it was placed upright with food inside.

[0039] Example 4 In Example 4, a packaging container was produced using a laminate sheet 2 made of the following material. The substrate 2A has a basis weight of 100 g / m 2 A paper substrate having a thickness of 157 μm was used. The barrier layer 2B and the sealant layer 2C were made of the same films as in Example 1. The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 4 also stood stably when it was placed upright with food inside.

[0040] Example 5 In Example 5, a packaging container was produced using a laminate sheet 2 made of the following material. The substrate 2A has a basis weight of 110 g / m 2 A paper substrate having a thickness of 177 μm was used. The barrier layer 2B and the sealant layer 2C were made of the same films as in Example 1. The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 5 also stood upright stably with food contained therein.

[0041] Example 6 In Example 6, a packaging container was produced using a laminate sheet 2 made of the following material. The substrate 2A has a basis weight of 120 g / m 2 A paper substrate having a thickness of 193 μm was used. The barrier layer 2B and the sealant layer 2C were made of the same films as in Example 1. The bottom fold depth 23h was set to the same dimension as in Example 1. The packaging container of Example 6 also stood upright stably with food contained therein.

[0042] Example 7 In Example 7, a packaging container was produced using a laminate sheet 2 made of the following material. The substrate 2A has a basis weight of 140 g / m 2 A paper substrate having a thickness of 221 μm was used. The barrier layer 2B and the sealant layer 2C were made of the same films as in Example 1. The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 7 also stood upright stably with food contained therein.

[0043] Example 8 In Example 8, a packaging container was produced using a laminate sheet 2 made of the following material. The substrate 2A has a basis weight of 80 g / m 2A paper substrate having a thickness of 139 μm was used. The barrier layer 2B was the same film as in Example 1. The sealant layer 2C was a non-oriented polypropylene film (CPP film) having a thickness of 30 μm. The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 8 also stood upright stably with food contained therein.

[0044] Example 9 In Example 9, a packaging container was produced using a laminate sheet 2 made of the following material. The base material 2A was the same paper base material as in Example 8. The barrier layer 2B was the same film as in Example 1. The sealant layer 2C was a 40 μm thick unstretched polypropylene film (CPP film). The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 9 also stood upright stably with food contained therein.

[0045] Example 10 In Example 10, a packaging container was produced using a laminate sheet 2 made of the following material. The base material 2A was the same paper base material as in Example 8. The barrier layer 2B was the same film as in Example 1. The sealant layer 2C was a 50 μm thick unstretched polypropylene film (CPP film). The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 10 also stood upright stably with food inside.

[0046] Example 11 In Example 11, a packaging container was produced using a laminate sheet 2 made of the following material. The base material 2A was the same paper base material as in Example 8. The barrier layer 2B was the same film as in Example 1. The sealant layer 2C was a 60 μm thick unstretched polypropylene film (CPP film). The bottom fold depth 23h was the same as in Example 1. The packaging container of Example 11 also stood upright with food inside it and was stable.

[0047] (Comparative Example 1) In Comparative Example 1, a packaging container was produced using a laminate sheet made of the following material. The substrate 2A has a density of 1.35 g / cm 3 (Converted to basis weight: 20g / m 2 A plastic film substrate having a thickness of 15 μm was used. The barrier layer 2B was the same film as in Example 1. The sealant layer 2C was a non-oriented polypropylene film (CPP film) having a thickness of 70 μm. The bottom fold depth was the same as in Example 1.

[0048] (evaluation) <Taber Fear> In Examples 1 to 11 and Comparative Example 1, the Taber stiffness (stiffness) of laminate sheet 2 was measured using a Taber stiffness tester in accordance with JIS-P8125:2000. If the stiffness was less than 0.95 mN·m, it was judged possible to fold the laminate sheet using a bag-making machine and was rated as "◎." If the stiffness was between 0.95 mN·m and 1.01 mN·m, it was judged possible to fold the laminate sheet using a bag-making machine and was rated as "○." The measured value for Example 1 was 0.27, for Example 2 0.34, for Example 3 0.44, for Example 4 0.63, for Example 5 0.66, for Example 6 0.84, for Example 7 1.01, and for Examples 8 to 11, all were 1.01 mN·m or less. Comparative Example 1 was too weak (too low stiffness) to be measured. The evaluation results are shown in Table 1.

[0049] <Seal strength> In Examples 1 to 11 and Comparative Example 1, the seal strength of the horizontal seal portions (side seal portion 24 and bottom seal portion 25) of the packaging containers was measured using the test method for heat-sealed flexible packaging bags and semi-rigid containers in accordance with JIS-Z0238:1998. A seal strength of 40 N / 15 mm or greater was deemed acceptable and rated as "◎", while a seal strength of greater than 23 [N / 15 mm] but less than 40 [N / 15 mm] was deemed acceptable and rated as "◯". The evaluation results are shown in Table 1. The Food Sanitation Act stipulates that the seal strength after retort (heat treatment) must be greater than 23 [N / 15 mm]. Here, the measured value for Example 1 was 61.1, the measured value for Example 2 was 54.2, the measured value for Example 3 was 49.5, the measured value for Example 4 was 47.1, the measured value for Example 5 was 48.8, the measured value for Example 6 was 45.7, the measured value for Example 7 was 25.8, the measured value for Example 8 was 30.1, the measured value for Example 9 was 25.4, and the measured values ​​for Examples 10 and 11 and Comparative Example 1 were all over 23 [N / 15mm].

[0050] <Transport drop test> In Examples 1 to 11 and Comparative Example 1, a drop test was conducted on 36 packaging containers using a transportation drop test (a free drop test among impact tests) in accordance with JIS-Z0200:2013 packaged cargo, and the evaluation was given as "◎" if the number of leaks was 0, and as "◯" if the number of leaks was 1 to 7. The test was conducted by dropping from a height of 60 cm. The evaluation results are shown in Table 1. Here, the number of leaks in Examples 1 to 7 was 4 or less, the number of leaks in Example 8 was 7, the number of leaks in Example 9 was 6, the number of leaks in Example 10 was 5, the number of leaks in Example 11 was 4, and the number of leaks in Comparative Example 1 was 7 or less.

[0051] [Table 1]

[0052] As can be seen from Table 1, it was confirmed that the stiffness of the laminated sheet 2 was 1.01 [mN m] or less in all of Examples 1 to 11. This confirmed that in Examples 1 to 11, the laminated sheet 2 could be folded using a bag making machine, and it was therefore possible to provide a packaging container 1 that could stand stably. In addition, taking into consideration the evaluation results of the seal strength and the transport drop test, the basis weight of the substrate 2A is 60 to 140 g / m 2 It was also confirmed that it is preferable to use a laminated sheet 2 in which a paper substrate having a thickness of 120 to 220 μm, a barrier layer 2B, and a CPP film having a thickness of 70 μm or more as a sealant layer 2C are laminated in this order. In addition to the above-mentioned examples, it was also confirmed that a packaging container 1 in which the bottom tuck-in depth dimension 23h was set to 15% to 25% of the height dimension 1h of the packaging container 1 was also able to stand on its own.

[0053] (Example 2-1A, Example 2-1B) In Examples 2-1A and 2-1B, a cutout 27 was provided in the bottom seal 25 of the packaging container of Example 2 at a position 5 mm (12.5%) from the bottom end. Height of bottom seal 25 in the X direction (Example 2-2A, Example 2-2B) In Examples 2-2A and 2-2B, a cutout 27 was provided in the bottom seal portion 25 of the packaging container of Example 2 at a position 20 mm (50%) from the lower end thereof. (Examples 2-3A and 2-3B) In Examples 2-3A and 2-3B, the bottom seal portion 25 of the packaging container of Example 2 does not have the cutout portion 27.

[0054] (Position of the cutout and bag breaking test) In Examples 2-1A to 2-3B, five packaging containers 1 were prepared by sealing them with 300 ml of water, and five packaging containers 1 were prepared by sealing them with 200 ml of water. Each packaging container 1 was dropped 10 times from a height of 50 cm containing 300 ml of water, and from a height of 100 cm containing 200 ml of water. Each packaging container 1 was dropped from the heights listed above 10 times, and the bag breakage was evaluated at the intersection (the area where the bottom seal 25 and the reinforcing seals 25a and 25b intersect), the reinforcing seals 25a and 25b, and the bottom 23. In Table 2, these are referred to as the intersection, V-seal, and bottom, respectively. Examples 2-1A, 2-2A, and 2-3A were before retort, and Examples 2-1B, 2-2B, and 2-3B were after retort. The evaluation results are shown in Table 2. Table 2 also shows the number of bags that broke out of the five.

[0055] [Table 2]

[0056] As can be seen from Table 2, it was confirmed that all of Examples 2-1A to 2-3B had sufficient bag-breaking strength. The Japanese Food Sanitation Act stipulates that the bag must be dropped twice from a height of 50 cm without breaking, and all of Examples 2-1A to 2-3B satisfied the standards of the Food Sanitation Act (not shown in the table). This evaluation method is stricter than the standards stipulated by the Food Sanitation Act. However, in Examples 2-3A and 2-3B, which have no cutouts, the number of broken bags was high, and from the viewpoint of improving strength against breakage, it is thought that packaging containers with cutouts are more preferable.

[0057] Furthermore, Examples 2-1A to 2-3B confirmed that it is preferable to position cutout 27 2 to 12 mm above bottom end 25c of bottom seal portion 25. This 2 to 12 mm position of cutout 27 corresponds to bottom fold-in depth 23h, i.e., 5 to 30% of the length of bottom seal portion 25 in the X direction. Note that the cutout positions in Table 2 are for a bottom fold-in depth 23h of 40 mm, and a cutout position of 5 mm corresponds to 12.5% ​​of bottom fold-in depth 23h. Furthermore, a cutout position of 20 mm corresponds to 50% of bottom fold-in depth 23h.

[0058] (Examples 2-4) In Example 2-4, a point seal portion 26 having a width that is 90% of the seal width of the side seal portion 24 and the bottom seal portion 25 was provided at the boundary between the side seal portion 24 and the bottom seal portion 25 of the packaging container of Example 2, spanning the side seal portion 24 and the bottom seal portion 25. (Examples 2-5) In Example 2-5, a point seal portion 26 having a width of 60% of the seal width of the side seal portion 24 and the bottom seal portion 25 was provided at the boundary between the side seal portion 24 and the bottom seal portion 25 of the packaging container of Example 2, spanning the side seal portion 24 and the bottom seal portion 25. (Examples 2-6) In Example 2-6, a point seal portion 26 having a width of 40% of the seal width of the side seal portion 24 and the bottom seal portion 25 was provided at the boundary between the side seal portion 24 and the bottom seal portion 25 of the packaging container of Example 2, spanning the side seal portion 24 and the bottom seal portion 25.

[0059] (Point seal width and transport drop test) In Examples 2-4 to 2-6, similarly to the previously described Examples 1-11 and Comparative Example 1, a transportation drop test (a free drop test among impact tests) in accordance with JIS-Z0200:2013 packaged cargo was conducted. Drop tests were conducted on 42 packages containing 200 ml of water, 36 packages containing 250 ml of water, and 30 packages containing 300 ml of water, and the number of leaks was evaluated. The tests were conducted by dropping from a height of 60 cm. The evaluation results are shown in Table 3.

[0060] [Table 3]

[0061] As can be seen from Table 3, it was confirmed that there was no leakage when the amount of water was 200 ml and when the amount of water was 250 ml in Example 2-5. This shows that the median value for the seal width of the point seal portion 26 relative to the seal widths of the bottom seal portion 25 and the side seal portion 24 is around 60%, and the range in which there is an improvement tendency is 40 to 90%. As described above, according to this embodiment, it is possible to provide a packaging container 1 that is stable, self-standing, and highly reliable.

[0062] (Embodiment 2) A packaging container 1A according to the second embodiment of the present invention has almost the same configuration as the packaging container 1 of the first embodiment described above, but differs in the following configuration. That is, as shown in Fig. 9, the packaging container 1A of embodiment 2 has a cutout area 31A in the hermetic seal portion 28 of each of the front portion 21 and the back portion 22. This cutout area 31 is surrounded by, for example, a perforation line, so that it can be easily cut out from the hermetic seal portion 28 after food is placed in the storage portion 30 and the hermetic seal portion 28 is sealed. In embodiment 2, as shown in Fig. 10, the cutout area 31A is elongated such that its length in the width direction (Y direction) is longer than its length in the height direction (X direction) so that a cutout hole 32A after cutting can be used as, for example, a handle.

[0063] In this way, by providing a long cutout area 31A in the sealed portion 28, the cutout hole 32A left after cutting out the cutout area 31A can be used as a handle, and by holding this cutout hole 32A as a handle, the packaging container 1A in a heated state after being heated in a microwave oven or the like can be easily transported. Furthermore, by devising a shape for the cutout area 31A, it is possible to use the cutout area 31A after cutting it out from the hermetic seal portion 28 as a tool such as a spoon, thereby enabling the hermetic seal portion 28 to be used effectively. When the cutout region 31A is provided in the hermetic seal portion 28, it is preferable to increase the width in the X direction compared to the hermetic seal portion 28 of the first embodiment described above to increase the seal strength.

[0064] (Embodiment 3) A packaging container 1B according to a third embodiment of the present invention has a cutout region formed in a different location. Specifically, as shown in Fig. 11, the packaging container 1B of the third embodiment has a cutout region 31B in each of two side seal portions 24 located on opposite sides in the width direction (Y direction). In this third embodiment, too, the cutout region 31B is surrounded by, for example, a perforation line, allowing it to be easily cut out of the side seal portion 24 after food is placed in the storage portion 30 and the hermetically sealed portion 28 is sealed. Furthermore, as shown in Fig. 12, the cutout region 31B is elongated, with its length in the width direction (Y direction) being longer than its length in the height direction (X direction), so that a cutout hole 32B after cutting can be used, for example, as a handle.

[0065] In this way, by providing a long cutout area 31B in each of the two side seal portions 24, the cutout hole 32B left after cutting out the cutout area 31B can be used as a handle, and by using this cutout hole 32B as a handle, the packaging container 1B in a heated state after being heated in a microwave oven or the like can be easily transported. Furthermore, by devising a shape for the cutout area 31B, it is possible to use the cutout area 31B after cutting it out from the hermetic seal portion 28 as a tool such as a spoon, thereby enabling effective use of the side seal portion 24.

[0066] When the cutout region 31B is provided in the side seal portion 24, it is preferable to increase the width in the Y direction compared to the first and second embodiments described above to increase the seal strength. Furthermore, in this third embodiment, the case where the cutout region 31B is provided in each of the two side seal portions 24 has been described, but it is also possible to provide the cutout region 31B in either one of the two side seal portions 24. In the above-described embodiment, the packaging containers 1, 1A, and 1B for ready meals have been described. However, the present invention is not limited to this embodiment and can be applied to packaging containers for beverages, food, and the like.

[0067] The present invention has been specifically described above based on the above-mentioned embodiments and examples, but the present invention is not limited to the above-mentioned embodiments and examples, and it goes without saying that various modifications can be made within the scope of the gist of the present invention. [Explanation of symbols]

[0068] 1...Packaging container 2...Laminated sheet 2A…Base material 2B: Barrier layer 2C...Sealant layer 21...Front 22...Back part 23…Bottom part 23a…first part 23b…Second part 24...Side seal 25...Bottom seal 26...Point seal section 27…Drilled section 28...Sealing part 29...Notch 30...Storage section 31A, 31B...Cutout area 32A, 32B...Cutout holes

Claims

1. the packaging material is a laminated sheet having at least a paper base material, a barrier layer, and a sealant layer laminated in this order, and has a front portion and a back portion arranged so that the sealant layers face each other, a bottom portion folded from one end side of the front portion and the back portion into the inside of the front portion and the back portion, a side seal portion formed by doubling up and sealing the widthwise edges of the front portion and the back portion, and a bottom seal portion formed by doubling up and sealing the widthwise edges of the front portion and the back portion and the widthwise edges of the bottom portion, The dimension of the bottom folding depth when the bottom surface portion is folded is 10 to 40% of the height dimension of the front surface portion and the back surface portion, a part of the folded portion located between the front surface portion and the bottom surface portion and a part of the folded portion located between the back surface portion and the bottom surface portion are not sealed, the bottom surface portion has a first portion facing the front surface portion and a second portion facing the back surface portion in a folded state; a cutout portion formed by removing a part of each of the first portion and the second portion is provided at the edge of the first portion and the second portion in the width direction; In the bottom seal portion, the sealant layers of the first portions of the front surface portion and the bottom surface portion are sealed to each other, the sealant layers of the second portions of the back surface portion and the bottom surface portion are sealed to each other, and the sealant layers of the front surface portion and the back surface portion are sealed to each other through the cut-out portions of the first portion and the second portion, a reinforcing seal portion extending obliquely from each edge in the width direction of the front portion and the back portion toward the folded portion and connected to the bottom seal portion corresponding to each edge, The reinforcing seal portion is a portion in which the sealant layers of the front portion and the first portion of the bottom portion, and the sealant layers of the back portion and the second portion of the bottom portion are double-stacked and sealed in a strip shape of a certain width.

2. 2. The packaging container according to claim 1, wherein a point seal having a width of 40 to 90% of the seal width is provided at the boundary between the bottom seal and the side seal.

3. The packaging container according to claim 1 or 2, characterized in that the cut-out portion is provided in the bottom seal portion at a position 5 to 50% of the bottom fold depth from the lower end of the bottom seal portion.

4. 4. The packaging container according to claim 1, wherein the side seal portion has a cutout area that can be cut out.

5. 5. The packaging container according to claim 4, wherein the cutout area has an elongated shape extending in the height direction of the front and back portions.

6. 6. The packaging container according to claim 4, wherein the cutout area has a shape similar to that of a dish.

7. The paper substrate has a basis weight of 60 to 140 g / m ２ , a paper substrate having a thickness of 120 to 220 μm; 7. The packaging container according to claim 1, wherein the sealant layer is a CPP film having a thickness of 70 μm or more.

8. preparing a laminated sheet in which a paper substrate, a barrier layer, and a sealant layer are laminated in this order, the laminated sheet being formed in a rectangular shape having a first direction and a second direction perpendicular to each other, and the laminated sheet being divided in this order along the first direction into a front portion, a first portion and a second portion of a bottom portion, and a back portion; folding the laminated sheet in two so that the sealant layers face each other and the first and second portions of the front and back surfaces and the bottom surface overlap each other; forming a cutout portion by removing a part of each of the first portion and the second portion at each edge on both sides in the second direction of the first portion and the second portion of the bottom surface portion while the first portion and the second portion are overlapped; folding the first and second portions between the front and back portions so that the cutouts of the first and second portions face each other and the first and second portions overlap each other; sealing the sealant layers of the front and back portions together in a strip shape with a constant width at both edges of the front and back portions in the second direction, the sealant layers of the front and back portions together in the first portion of the bottom portion, the sealant layers of the back and back portions together in the second portion of the bottom portion, and the sealant layers of the front and back portions together through the cut-outs in the first and second portions, while leaving unsealed a part of a folded portion located between the front and back portions and the first portion of the bottom portion, and a part of a folded portion located between the back and back portions and the second portion of the bottom portion; Equipped with At both edges of the front surface portion and the back surface portion in the second direction, the sealant layers of the first portions of the front surface portion and the bottom surface portion, the sealant layers of the second portions of the back surface portion and the bottom surface portion, and the sealant layers of the front surface portion and the back surface portion through the cut-out portions of the first portions and the second portions form bottom surface seal portions in which the sealant layers are sealed together in a strip shape with a constant width, A method for manufacturing a packaging container, characterized in that a reinforced seal portion is formed by sealing the sealant layers of the first portion of the front portion and the bottom portion, and the sealant layers of the second portion of the back portion and the bottom portion together in a strip shape of a constant width, so that the reinforced seal portion extends diagonally from each edge side in the width direction of the front portion and the back portion toward the folded portion and connects to the bottom seal portion corresponding to each edge side.

Images