Ziplock paper container

Abstract

To provide a zippered paper container in which damage (cracking) is less likely to occur in a folded portion of a top side protruding part interposed between a top part and the top side protruding part, when the top side protruding part is folded in a direction of the body of the zippered paper container and joined to the body.SOLUTION: In a zippered paper container in which a blank plate composed of a laminated sheet 78 including a paper base layer 782 is assembled, the blank plate includes at least a front side blank plate and a back side blank plate, and at least the laminated sheet 78 of the front side blank plate has a paper base protection layer 788 on one of outer side layers of the paper base layer 782.SELECTED DRAWING: Figure 13A

Description

[Technical field]

[0001] The present disclosure relates to a paper container with a zipper, and in particular to a paper container with a zipper that is three-dimensional and self-supporting, and that is able to maintain its aesthetic appearance with less damage to the laminated sheet at the folded portion of the protruding top part. [Background technology]

[0002] Conventionally, a technology for a paper container with a zipper has been disclosed, such as that in Patent Document 1. That is, a zipper is provided on the top of a rectangular parallelepiped paper container, and the zipper can be opened when the contents are to be removed, and closed when the contents have been removed.

[0003] The above technology can protect the contents and prevent the contents from spilling when the paper container falls over. Also, because it is a paper container, it is easy to reduce the volume of the container and dispose of it after the contents are consumed. Figure 1 shows a blank plate 81 used to manufacture a paper container 80 with a zipper of the prior art, Figure 2 shows a perspective view of the paper container 80 with a zipper of the prior art, and Figure 3 shows a plan view. Starting from the upper edge of the resealable paper container 80, there are an easy-to-open processing line 851 for opening the top portion 871 of the resealable paper container 80, and a zipper tape 861 for freely opening and closing the top portion 871 of the opened resealable paper container 80.

[0004] In addition, unless otherwise specified, referring to Fig. 2, the front wall panel 831b is regarded as the front side, and the front, back, left, right, top, and bottom sides of the chuckable paper container 80 are indicated. The same applies to the chuckable paper container 90 of the present disclosure. In addition, the reference numbers used when describing the prior art are in the 80s or 800s to distinguish them from the present disclosure.

[0005] The laminated sheet 88 of the blank board 81 has a base layer of paper and a synthetic resin layer on at least the back surface of the base layer. The synthetic resin layer may be a single layer or multiple layers.

[0006] As an example, a laminated sheet 88 having a three-layer structure is shown in Fig. 5A. The layer structure is as follows. (Surface side) Outermost thermoplastic resin layer 881 / Paper base layer 882 / Innermost thermoplastic resin layer 883 (back side)

[0007] As an example, a laminated sheet 88 having a two-layer structure is shown in Fig. 5B. The layer structure is as follows. (Front side) Paper base layer 882 / Innermost thermoplastic resin layer 883 (Back side) This layer structure is obtained by excluding the outermost thermoplastic resin layer 781 from the three-layered blank plate 10 shown in FIG. 5A.

[0008] Furthermore, when laminate sheet 88 requires barrier properties (water vapor, oxygen, aroma retention, etc.), it can be provided with barrier layer 885. Fig. 5C is a cross-sectional view of laminate sheet 88 consisting of five layers, and the layer structure is as follows. (Front side) Outermost thermoplastic resin layer 881 / Paper base layer 882 / Middle adhesive layer 884 / Barrier layer 885 / Innermost thermoplastic resin layer 883 (Back side)

[0009] FIG. 5D is a cross-sectional view of a laminated sheet 88 made up of four layers, the layer configuration of which is as follows: (Surface) Paper base layer 882 / Middle adhesive layer 884 / Barrier layer 885 / Innermost thermoplastic resin layer 883 (back side) This layer structure is the same as that of the five-layer laminate sheet 88 shown in FIG. 5C, except that the outermost thermoplastic resin layer 881 is removed.

[0010] The layers of the laminated sheets 88 are bonded together by known methods such as dry lamination, extrusion coating, adhesives, etc. Note that the layers for bonding the layers together are not shown because they are thin.

[0011] The outermost thermoplastic resin layer 881 and the innermost thermoplastic resin layer 883 are, for example, low-density polyethylene (LDPE). The middle adhesive layer 884 is, for example, a random copolymer of ethylene and methacrylic acid (EMAA). The barrier layer 885 is, for example, a silica-deposited polyethylene terephthalate (hereinafter sometimes abbreviated as PET) film.

[0012] However, when the top side protrusion 874 is strongly bent toward the body portion 872 (at approximately a right angle), the outer surface of the folded portion 876 of the top side protrusion 874, which is located between the top side protrusion 874, the upper stacking plate 834, and the top plate 833, becomes strongly stretched, which may cause damage (cracks) 879 to occur in the laminated sheet 88 of the zipper-equipped paper container 80 of the conventional technology, as shown in Figure 4. 4 is an enlarged view of a portion of the cross section taken along the cross-sectional position AA shown in FIG.

[0013] The damage (cracks) shown in the drawings are merely examples of damage, and the form of damage is not limited to these.

[0014] This is because the upper part of the prior art zippered paper container 80 is sealed by joining the inner surfaces of the upper overlapping plates 834 together, resulting in a large number of layers in that part and making it thicker. Furthermore, since the zipper tape 861 is also joined to the upper overlapping plate 834, the number of layers in that portion increases, and the thickness of that portion becomes even thicker.

[0015] In addition, in Fig. 4, the cross section of the laminated sheet 88 of the blank plate 81 of the conventional paper container 80 with a zipper is shown as one layer, but the layer structure of the laminated sheet 88 of the blank plate 81 is a multi-layered laminated sheet 88. However, in this figure, it is shown as one layer for ease of viewing.

[0016] At the bent portion 876 of the top side protrusion 874, four laminated sheets 88 overlap with the zipper tape 861. With reference to each component shown on the blank plate 81 in Fig. 1, from the outside, there are the connection portion between the front side upper overlapping plate 834b and the front side top side side plate 843b, the zipper tape 861, the connection portion between the rear side upper overlapping plate 834a and the rear side top side plate 843a, the connection portion between the rear side top panel 833a and the rear side top protrusion margin 838a, and the connection portion between the rear side panel 832a and the rear side top protrusion margin 838a.

[0017] Many of the laminated sheets 88 of the conventional paper containers 80 with zip closures are made of a paper base layer 882 and a synthetic resin film layer, and among these components, cracks are likely to occur in the paper base layer 882, which has poor tensile strength. When the sheet is stretched particularly strongly, cracks may occur not only in the paper base layer 882 but also in the inner synthetic resin film layer.

[0018] If cracks occur in the synthetic resin film layer, there may be a decrease in the barrier properties (oxygen, water vapor, aroma retention, etc.) of the laminated sheet 88. In particular, when the synthetic resin film layer itself has barrier properties or when the synthetic resin film layer is subjected to vapor deposition processing, a decrease in barrier properties may be observed.

[0019] Furthermore, damage (cracks) 879 in laminate sheet 88 occurs irregularly, and the paper base layer 882 at the cross section of the damage (crack) 879 is torn and looks ugly. This reduces the aesthetics of the zipper-equipped paper container 80, and if the part of laminate sheet 88 that is damaged has printing on it, the letters or pictures displayed by the printing may be damaged.

[0020] In addition, in each of the zippered paper containers 80 made of the laminated sheets 88 shown in Figures 5A, 5B, 5C, and 5D, there is a risk of damage (cracks) occurring at the folded portion 876 of the top protrusion 874. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] JP 2005-178833 A Summary of the Invention [Problem to be solved by the invention]

[0022] The present disclosure has been made to solve the above problems, and its object is to provide a paper container 90 with a zipper that is less likely to suffer damage (cracks) in the folded portion 76 of the top side protrusion 74, which is interposed between the top side protrusion 74 and the front top panel 33b and the front upper overlapping plate 34b, when the top side protrusion 74 is folded toward the body portion 72 of the paper container 90 and joined to the body portion 72. [Means for solving the problem]

[0023] The above problems can be solved by the following embodiments of the present disclosure. That is, the retractable paper container 90 of the present disclosure has the following features: In a paper container 90 with a zipper, a blank plate 10 made of a laminated sheet 78 including a paper base layer 782 is assembled. The blank plate 10 includes at least a front blank plate 10b and a back blank plate 10a. A top portion 71 is provided at the top of the zipper-equipped paper container 90, and includes an upper overlapping plate 34 formed by overlapping and joining the front blank plate 10b and the back blank plate 10a, and a top plate 33 connected to the lower side of the upper overlapping plate 34; A top side plate 41 is provided on both the left and right sides of the upper overlapping plate 34, A top-side protrusion 74 is provided on both the left and right sides of the top portion 71, A body portion 72 provided below the top portion 71; A bottom portion 73 provided on the lower side of the body portion 72; an upper seal portion 53 that crosses the upper edge portion 21 or the vicinity of the upper edge portion 21 of the upper overlapping plate 34 and the side plate 41 of the top portion; a zipper tape 61 located below the upper seal portion 53 and extending across the upper overlapping plate 34 and the side plate 41 of the top portion; At least the laminated sheet 78 of the front blank plate 10 b has a paper base protective layer 788 on any one of the outer layers of the paper base layer 782 .

[0024] In addition, in the paper container 90 with a zipper according to an embodiment of the present disclosure, The paper base protective layer 788 may be a film with a greater tensile strength than polyethylene.

[0025] In addition, in the paper container 90 with a zipper according to an embodiment of the present disclosure, The paper base protective layer 788 may be a film having a tensile modulus greater than that of polyethylene.

[0026] In addition, in the paper container 90 with a zipper according to an embodiment of the present disclosure, The paper substrate protective layer 788 may be a stretched polyethylene terephthalate film.

[0027] In addition, in the paper container 90 with a zipper according to an embodiment of the present disclosure, The paper base material protective layer 788 may be a stretched nylon film. The top protrusion folding line 15 with zipper may be a single circular arc.

[0028] In addition, in the paper container 90 with a zipper according to an embodiment of the present disclosure, The paper base protective layer 788 may be an oriented polypropylene film.

[0029] In addition, in the paper container 90 with a zipper according to an embodiment of the present disclosure, The thickness of the paper base protective layer 788 may be 10 μm or more and 200 μm or less. Effect of the Invention

[0030] According to the embodiment of the present disclosure described above, when the top-side protrusions 74 connected to both the left and right sides of the top 71 of the resealable paper container 90 are joined to the body 72 of the resealable paper container 90, the paper base material layer 782 of the laminated sheet 78 of the folded portion 76 of the top-side protrusions 74 is protected by the paper base material protective layer 788 provided on one of the outer layers. Therefore, the folded portion 76 of the top-side protrusions 74 is less likely to be damaged (cracked). [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a development view of a blank plate 81 used in manufacturing a paper container 80 with a zipper according to the prior art. [Diagram 2] FIG. 1 is a perspective view of a resealable paper container 80 of the prior art. [Diagram 3] FIG. 1 is a plan view of a resealable paper container 80 of the prior art. [Figure 4] 13 is an enlarged cross-sectional view of a folded portion 876 at a joining position of a zipper tape 861 of a top surface protrusion 874 of a zippered paper container of the prior art (see cross-sectional position AA in FIG. 3). [Figure 5A] FIG. 2 is a cross-sectional view of a laminated sheet 88 of one embodiment of a blank plate 81 of the prior art. [Figure 5B] FIG. 13 is a cross-sectional view of a laminated sheet 88 of another embodiment of a blank plate 81 of the prior art. [Figure 5C] 13 is a cross-sectional view of a laminated sheet 88 of yet another embodiment of a blank plate 81 of the prior art. [Figure 5D] FIG. 1 is a cross-sectional view of a laminated sheet 88 of yet another embodiment of the blank plate 81 of the prior art. [Figure 6A] 1 is a development view of a front blank plate 10a used in manufacturing a resealable paper container 90 according to an embodiment of the present disclosure. [Figure 6B] 1 is a development view of a rear blank plate 10b used in manufacturing a resealable paper container 90 according to an embodiment of the present disclosure. [Figure 7] FIG. 6C is a front view showing the shape of a paper container (in a flat state) 91 at an intermediate stage when a paper container 90 with a zipper is produced using the blank plate 10 shown in FIGS. 6A and 6B. [Figure 8] FIG. 6C is a perspective view showing the shape of a paper container (in a raised box state) 92 at an intermediate stage when a paper container 90 with a zipper is produced using the blank plate 10 shown in FIGS. 6A and 6B. [Figure 9] FIG. 6C is a perspective view of a paper container 90 with a zipper produced using the blank plate 10 shown in FIGS. 6A and 6B. [Figure 10] FIG. 10 is a side view of the zippered paper container 90 shown in FIG. [Figure 11] FIG. 10 is a plan view of the zippered paper container 90 shown in FIG. [Figure 12] 10 is a perspective view of the zippered paper container 90 shown in FIG. 9 with the top portion 71 open. [Figure 13A] FIG. 2 is a cross-sectional view of a laminated sheet 78 of one embodiment of the blank plate 10 of the present disclosure. [Figure 13B] FIG. 2 is a cross-sectional view of a laminated sheet 78 of another embodiment of the blank plate 10 of the present disclosure. [Figure 13C] 13 is a cross-sectional view of a laminated sheet 78 of yet another embodiment of the blank plate 10 of the present disclosure. [Figure 14] 11 is an enlarged cross-sectional view of a folded portion 76 at a joining position of a zipper tape 61 of a top-side protruding portion 74 in the zippered paper container 90 shown in FIG. 9 (see cross-sectional position BB in FIG. 11). [Figure 15A] 7 is an enlarged cross-sectional view of one embodiment of a joint between a blank plate 10 and a zipper tape 61 (see cross-sectional position CC in FIG. 7). [Figure 15B] 7 is an enlarged cross-sectional view of another embodiment of the joint between the blank plate 10 and the zipper tape 61 (see cross-sectional position CC in FIG. 7). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The present disclosure will be described below with reference to the drawings, however, the present disclosure is not limited to the specifically illustrated embodiments or various specifically described structures. In each drawing, the size and ratio of the components may be changed or exaggerated for ease of understanding, and parts that are unnecessary for the explanation or repeated reference numerals may be omitted for ease of viewing.

[0033] In addition, the numerical values ​​such as dimensions of each member and the names of materials described in this specification are examples of embodiments, and are not limited to these, and may be appropriately selected and used. In this specification, terms that specify shapes or geometric conditions, such as parallel, orthogonal, and perpendicular, are intended to include substantially the same state in addition to their strict meanings.

[0034] The blank plate 10 of the chuckable paper container 90 of the present disclosure is formed into a rectangular outer shape using a laminated sheet 78 in which a paper base layer 782 is laminated, a paper base protective layer 788 is laminated to one of the outer layers of the paper base layer 782, and a thermoplastic resin such as polyethylene is laminated as at least the innermost layer, and various folding lines are provided in the blank plate 10 to separate the forming plates for each part required to form the chuckable paper container 90. The paper base layer 782 may have only one outer layer, in which case the outer layer serves as the paper base protective layer 788 .

[0035] <First embodiment> <Blank board> The blank plate 10 of the chuckable paper container 90 of this embodiment is shown in Figures 6A and 6B. Figure 6A shows the back blank plate 10a, and Figure 6B shows the front blank plate 10b. The back blank plate 10a and the front blank plate 10b are collectively referred to as the blank plate 10.

[0036] Unless otherwise specified, in each component of the blank plate 10 described below, the subscript a of each symbol indicates an element of the back blank plate 10a, and the subscript b indicates an element of the front blank plate 10b. For elements with both the subscripts a and b, the symbol without a subscript includes both a and b.

[0037] The back side upper edge portion 21a, which is the bottom side of the back side blank plate 10a in FIG. 6A, becomes the top side of the resealable paper container 90. The front-side upper edge portion 21b, which is the upper side of the front-side blank plate 10b in FIG. 6B, becomes the upper side of the resealable paper container 90.

[0038] In both Figures 6A and 6B, the front side of the drawing corresponds to the outer side when the resealable paper container 90 is assembled, and the back side corresponds to the inner side. Figures 6A and 6B are symmetrical with respect to the respective upper edges 21a, 21b, except for some components (such as the top protrusion fold line 15) described below, and when the inner surfaces of the back blank plate 10a and the front blank plate 10b are aligned and overlapped, the respective components (the forming plates, lines, sealing portions, zipper tape joints, etc. described below) overlap.

[0039] The back blank plate 10a and the front blank plate 10b are aligned and stacked and joined to produce an intermediate stage paper container with a zipper (flat state) 91 as shown in Figure 7, and then an intermediate stage paper container with a zipper (raised state) 92 as shown in Figure 8 is produced, progressing through the steps to complete the paper container with a zipper 90; this manufacturing process will be described later.

[0040] Unless otherwise specified, the top, bottom, left and right of the front blank plate 10b will be shown with reference to Figure 6B. The back blank plate 10a will also be described with its upper edge 21a as the top side. Therefore, the top and bottom are reversed in Figure 6A. In the paper container 90 with a zipper, the upper edge 21 side is the upper side, and the lower edge 26 side is the lower side.

[0041] As will be described later, the formed resealable paper container 90 is composed of, from the top, a top portion 71, a body portion 72, and a bottom portion 73, and the top portion may be referred to as the top portion and the bottom portion may be referred to as the bottom portion (see FIG. 9). In addition, when describing the up-down direction of each component provided on the top 71, the term "top side" may refer to the upper edge 21 side, and when describing the up-down direction of each component provided on the bottom 73, the term "bottom side" may refer to the lower edge 26 side.

[0042] As described above, the rear blank plate 10a and the front blank plate 10b are substantially vertically symmetrical in shape, so the blank plate 10 will be described with reference to the front blank plate 10b. Moreover, the rear blank plate 10a and the front blank plate 10b are made of the same material (layer structure) and are manufactured by the same method.

[0043] The front blank plate 10b of the zippered paper container 90 of this embodiment is formed into a substantially rectangular shape by using a laminated sheet 78 in which at least a base paper is laminated and at least a thermoplastic resin such as polyethylene is laminated as the innermost layer. With reference to Fig. 6B, the upper side is the upper edge portion 21b, the left and right sides are the front side edge portions 11b, and the lower side is the lower edge portion 26b. The front blank plate 10b has a shape that is symmetrical with respect to a vertical line passing through the center of the front blank plate 10b in the width direction. The laminated sheet 78 will be described later.

[0044] The front blank plate 10b is provided with, in the transverse direction from the front upper edge 21b, a front first horizontal fold line 22b, a front second horizontal fold line 23b, a front third horizontal fold line 24b, and a front fourth horizontal fold line 25b. It is preferable that the front side horizontal fold lines 22b, 23b, 24b, 25b are parallel to the front side upper edge 21b and the front side lower edge 26b, respectively.

[0045] The front blank plate 10b is provided with, from the left side, a front first vertical folding line 12b, a front second vertical folding line 13b, a front second vertical folding line 13b, and a front first vertical folding line 12b. That is, the vertical folding line closer to the side edge 11b of each front blank plate 10b is the front first vertical folding line 12b, and the vertical folding line farther from the side edge 11b of each front blank plate 10b is the front second vertical folding line 13b. It is preferable that each of these front longitudinal folding lines 12b, 13b is approximately parallel to the side edge portion 11b of the front blank plate 10b.

[0046] Furthermore, a pair of diagonal fold lines 17b on the top side of the front surface and a pair of diagonal fold lines 18b on the bottom side of the front surface are provided on the left and right sides, and the forming plates of each part required for forming the zippered paper container 90 are partitioned and configured.

[0047] The upper end of the front top diagonal folding line 17b is at the same position as the front first top intersection point Eb, which is the intersection point of the front first vertical folding line 12b and the front first horizontal folding line 22b. The lower end of the front top diagonal folding line 17b is at the same position as the front second top intersection point Fb, which is the intersection point of the front second vertical folding line 13b and the front second horizontal folding line 23b.

[0048] The upper end of the front bottom diagonal fold line 18b is at the same position as the front second bottom intersection point Hb, which is the intersection point of the front second vertical fold line 13b and the front third horizontal fold line 24b. The lower end of the front bottom diagonal fold line 18b is at the same position as the front first bottom intersection point Gb, which is the intersection point of the front first vertical fold line 12b and the front fourth horizontal fold line 25b.

[0049] The oblique folding lines 17b on the front side may be located near the intersections Eb and Fb without contacting them. Furthermore, the oblique folding lines 18b on the front side may be located near the intersections Gb and Hb without contacting them. By positioning each of the above-mentioned front diagonal folding lines and each intersection point in close proximity without touching each other, it is possible to maintain sufficient folding performance while preventing excessive concentration of folding lines at any particular location, thereby preventing a decrease in the strength of the laminated sheet of the front blank plate 10b.

[0050] At both left and right side edge portions 11b of the front blank plate 10b, front side edge seal portions 36b are formed via the front first vertical folding lines 12b.

[0051] A front bottom seal margin 37b is formed at a front lower edge portion 26b located below the front blank plate 10b via a front fourth horizontal folding line 25b.

[0052] Further, the front blank plate 10b is provided with forming plates for each part in sequence downward from the front upper edge 21b located at the uppermost side.

[0053] Regarding the main part, a front upper overlapping plate 34b is provided below the central region of the front upper edge 21b. A front top panel 33b is connected to the bottom of the front upper overlapping plate 34b via a front first horizontal bending line 22b. A front wall panel 31b is connected to the bottom of the front top panel 33b via a front second horizontal bending line 23b. A front bottom panel 35b is connected to the bottom of the front wall panel 31b via a front third horizontal bending line 24b.

[0054] Further, side plates 41b of the top part of the front side are connected to the outside of both the left and right sides of the front side upper overlapping plate 34b via the front side second vertical folding line 13b.

[0055] Further, a front top protruding portion margin 38b is connected to the outside of both the left and right sides of the front top panel 33b via the front second vertical folding line 13b.

[0056] Further, a front side panel 32b is connected to the outside of both the left and right sides of the front wall panel 31b via a front second vertical bending line 13b.

[0057] Further, a front bottom protruding portion margin 43b is connected to the outside of both the left and right sides of the front bottom panel 35b via a front second vertical folding line 13b.

[0058] In addition, the top protruding portion 38b is connected to the bottom of each top side panel 41b via the first horizontal bending line 22b. The top protruding portion 38b is connected to the bottom of the top protruding portion 38b via the second horizontal bending line 23b. The bottom protruding portion 43b is connected to the bottom of the side panel 32b via the third horizontal bending line 24b.

[0059] Bottom seal portions 37b are connected to the lower sides of the front bottom plate 35b and the front bottom protruding portions 43b on both the left and right sides thereof.

[0060] The front side edge seal portion 36b is connected to the left and right outer sides of the above-mentioned side plate 41b of the front top portion, the front top protruding portion 38b, the front side plate 32b, and the front bottom protruding portion 43b via the front first vertical fold line 12b.

[0061] In the present embodiment, the process of providing folding lines to the blank sheet 10 (creasing process) is performed after the laminated sheet 78 is completed, and then the laminated sheet is fed to a machine that manufactures the resealable paper container 90. Alternatively, the creasing process may be performed by the machine that manufactures the resealable paper container 90.

[0062] As the method for forming the creasing lines, an appropriate method is adopted from among known methods such as a platen method and a rotary die method. Also, the laminated sheet 78 may be cut into sheets before the scoring process is performed, or the laminated sheet 78 may be supplied to the scoring process in a roll form.

[0063] Next, a punching process for manufacturing the blank plate 10 by punching the laminated sheet 78 will be described. For the punching process, an appropriate method is selected from known methods such as a platen method and a rotary die method. The blank plate 10 may be formed directly from the rolled laminated sheet 78, or the sheet may be cut into sheets and then punched. The order of the creasing and punching processes does not matter. They may be done at the same time.

[0064] In addition, a roll-shaped laminated sheet 78 slit to a specified roll width may be fed to a machine for manufacturing a paper container 90 with a zipper, and the roll-shaped laminated sheet 78 may be cut in the cross direction to produce a blank plate 10.

[0065] The rear blank sheet 10a and the front blank sheet 10b are line-symmetrical and have the same shape. In other words, they are blank sheets of substantially the same shape but with the layer structure of the blank sheets reversed.

[0066] Fig. 7 is a front view showing the shape of a chucked paper container (flat state) 91 at an intermediate stage when manufacturing a chucked paper container 90 using the blank plate 10 shown in Fig. 6A and Fig. 6B. The topmost part is the upper edge 21b of the front blank plate 10b shown in Fig. 6B, and on its back side is the back blank plate 10a. The back blank plate 10a cannot be seen with the naked eye, but when viewed through, it has almost the same shape as the front blank plate 10b.

[0067] In Figure 7, the back blank plate 10a and the front blank plate 10b are overlapping, and since each component has the same positional relationship when viewed through the drawing within the range of manufacturing variations, the notation and suffixes for the front side may be omitted in the explanation.

[0068] On the upper overlapping plate 34 and the side plate 41 of the top surface, at a predetermined position where the two blank plates mentioned above overlap each other, an upper seal portion 53 as a transverse sealing means and a zipper tape joint portion 52 are provided in sequence from the upper edge portion 21.

[0069] The upper seal portion 53 is provided at or near the upper edge 21 of the upper overlapping plate 34 and each of the top side plates 41 . When the upper seal portion 53 is approximately parallel to the upper edge portion 21, the length of the upper seal portion 53 can be shortened, and no waste is generated in the blank plate 10.

[0070] The upper seal portion 53 as a transverse sealing means is formed by joining the opposing front-side upper seal portion 53b and back-side upper seal portion 53a. The joining is performed so as to traverse the entire width of the upper edge portion 21 of the resealable paper container 90 or the vicinity of the upper edge portion 21, so that the resealable paper container 90 is kept airtight.

[0071] Additionally, it is desirable that the upper seal portion 53 be approximately parallel to the upper edge portion 21. Furthermore, it is desirable that the zipper tape joint portion 52 be approximately parallel to the upper edge portion 21. In such a configuration, it is easy to open and close the zipper tape 61 and to remove the contents. Also, the length of the zipper tape 61 can be shortened.

[0072] <Easy-to-open processing line> The easy-open processing line 51 will now be described. The front upper overlapping plate 34b and the side plate 41b of the top part of the front side may be provided with a front easy-open processing line 51b as an opening means. By providing the easy-open processing line 51b, the zippered paper container 90 can be opened without using tools such as scissors.

[0073] As shown in FIG. 7, the easy-open processing line 51 extends from one side edge 11 to the other side edge 11 of the blank sheet 10 and exists between the upper seal portion 53 and the zipper tape 61 .

[0074] A notch 77 may be provided at either end of the easy-open processing line 51, and in this embodiment, the notch 77 is provided at the right side edge 11. The notch 77 may also be provided at the left side edge 11. Alternatively, notches 77 may be provided at both the left and right side edges 11. Providing the notch 77 makes initial opening easier.

[0075] By cutting the easy-open processing line 51 from one side edge (here the right side) 11 to the other side edge (here the left side) 11, the upper overlapping plate 34 and the side plate 41 of the top of the front side are cut transversely, and the upper seal portion 53 is also cut away, exposing the zipper tape 61.

[0076] When an intermittent half-cut line or a straight half-cut line is used for the easy-open processing line 51 of the opening means, it may be formed by a method using a normal blade, but a half-cut line with greater precision and stability can be formed by using a method using laser light irradiation, a method using ultrasonic waves, or a method called diamond cutting.

[0077] Moreover, easy-open processing line 51 may be in the shape of a band having a width. Moreover, a plurality of easy-open processing lines 51 may be provided. By providing a plurality of easy-open processing lines 51, it is possible to prevent the easy-open processing lines 51 from being cut off in an undesired manner.

[0078] The easy-open processing line 51b may not be provided depending on the material, layer structure, and easy-open processing conditions of the laminated sheet 78 of the front blank plate 10b. Even without the easy-open processing line 51b, it may be possible to open the package by hand.

[0079] Furthermore, when the easy-opening process line 51b is not provided as described above, the container may be opened with a blade such as scissors. In that case, the intended opening line may be indicated by printing. The printing position may be printed at the position of the easy-opening process line 51b shown in FIG. 6B. The intended opening line may not be clearly indicated on the chuck-equipped paper container 90, but may be indicated in an attached instruction manual, etc.

[0080] <Zipper tape> The zipper tape 61 includes a male zipper tape 61m and a female zipper tape 61f each formed by extrusion molding, and a male zipper tape fitting portion 63m and a female zipper tape fitting portion 63f are fitted together.

[0081] <Zipper tape joining procedure> The procedure for assembling the zippered paper container 90 will be described later, but here, the procedure for joining the zipper tape 61 will be described.

[0082] In this case, the zipper tape joint portion 52 is a portion to be joined by the zipper tape 61 when assembling the zippered paper container 90.

[0083] The rear blank sheet 10a and the front blank sheet 10b are overlapped, and the side edge seal portions 36 and the upper seal portions 53 are heat sealed together. At this time, the zipper tape 61, in which the male zipper tape 61m and the female zipper tape 61f are previously fitted to the male zipper tape fitting portion 63m and the female zipper tape fitting portion 63f, is inserted into this portion. At the same time, the zipper tape joint portion 52 of the two blank sheets 10 is heated and pressurized from the outer surfaces of the two blank sheets 10. Then, the blank sheets 10 and the zipper tapes 61 are heat-sealed (see Figs. 15A and 15B).

[0084] The method of joining the zipper tape 61 to the blank plate 10 is not limited to the above-mentioned heat sealing, and other methods such as adhesive or adhesive tape may be used.

[0085] By heat-sealing the zipper tape 61 in this manner, there is less misalignment in the heat seal compared to a method in which the male zipper tape 61m and the female zipper tape 61f are separately heat-sealed to the zipper tape joint 52, and the attachment process is simplified, so that the zipper tape 61 can be attached with high production efficiency.

[0086] <Laminated sheet of blank boards> As described above, the laminated sheet 78 used for the blank plate 10 is a laminated sheet 78 having at least a paper base layer 782 laminated thereto, and at least the innermost thermoplastic resin layer 783 made of a thermoplastic resin such as polyethylene. However, if necessary, the intermediate layers may be provided with a barrier layer 785 against water vapor, oxygen or other substances, or a strength-enhancing layer.

[0087] The paper substrate protective layer 788 will now be described. When the top protrusion 74 is folded towards the body 72, the outer side of the folded portion 76 is stretched. In a laminated sheet that does not have the paper substrate protective layer 788, the paper substrate layer 782 is stretched and damaged. Here, the paper substrate protective layer 788 is a film that has high tensile strength and does not stretch easily when pulled. The paper substrate layer 782 that is bonded directly or nearby to the film is protected by the paper substrate protective layer 788, and is stretched less (length), so it is not damaged (broken).

[0088] The film used for the paper base material protective layer 788 is preferably one that has high tensile strength and does not stretch easily when pulled as described above. Furthermore, since it is used as a packaging material, it is required to have flexibility that allows it to be stored in a roll, ease of cutting during processing, stretchability during creasing, low cost, and hygiene when used as a product container.

[0089] Materials that satisfy these conditions include synthetic resin films, and among these, synthetic resin films that are suitable for stretching are preferable. Examples of films that satisfy the above conditions include oriented polyethylene terephthalate (PET), oriented nylon (hereinafter sometimes referred to as ONy), and oriented polypropylene (hereinafter sometimes referred to as OPP).

[0090] The thickness of these films is preferably 10 μm or more and 200 μm or less. If the thickness of the film is less than 10 μm, the tensile strength and elongation are poor. If the thickness exceeds 200 μm, it becomes difficult to perform folding and creasing, and the cost of the film increases more than necessary.

[0091] The paper base layer 782 will now be described. The paper base layer 782 is preferably made of paper that is rigid and does not easily crack when folded along a folding line, but is not particularly limited and can be appropriately selected and used depending on the contents to be filled into the chuck-equipped paper container 90, taking into consideration water resistance (size degree), etc. As specific examples, wood-free paper, cup base paper, milk carton base paper, etc. can be suitably used, and the basis weight thereof is 80 to 320 g / m 2 The range is appropriate.

[0092] The thermoplastic resin layer (sealant layer) used for the innermost layer, and the outermost layer and intermediate layer as required will be explained below. The resins that can be used for the thermoplastic resin layer (sealant layer) include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-α-olefin copolymers polymerized using single-site catalysts, ethylene-vinyl acetate copolymers (EVA), ethylene-acrylic acid copolymers (EAA), ethylene-methacrylic acid random copolymers (EMAA), ethylene-methyl acrylate copolymers (EMA), ethylene-ethyl acrylate copolymers (EEA), ionomers, polypropylene and its copolymers, polyester resins, etc., and from these, the most suitable one can be selected and used according to the contents to be filled and the conditions of storage and use.

[0093] Of the above thermoplastic resins, ethylene-methyl acrylate copolymer (EMA) and ethylene-methacrylic acid random copolymer (EMAA) are particularly excellent in thermal stability during processing such as extrusion coating, adhesion to various substrates, and low-temperature heat sealability, as well as in thin-film formability. Therefore, it is easy to extrusion coat and laminate the outermost thermoplastic resin layer, which does not require a large thickness, at a relatively thin thickness of, for example, 6 to 10 μm, making it possible to reduce the proportion of plastic materials used and also achieving cost benefits.

[0094] The thermoplastic resin layer (sealant layer) of the innermost layer, and, if necessary, the outermost layer and the intermediate layer, as described above, may be laminated by extrusion coating the resin on the laminated surface after subjecting the laminated surface to an easy-adhesion treatment such as anchor coating, corona treatment, frame (flame) treatment, etc., as necessary, or by forming the thermoplastic resin into a film in advance and laminating the film by bonding it together using a known dry laminate or extrusion laminate (sandwich laminate) method, etc.

[0095] When the barrier layer 785 is laminated on the intermediate layer of the laminated sheet 78, a metal foil such as an aluminum foil, or a vapor-deposited film in which a metal or inorganic oxide such as aluminum, silica, or alumina is vapor-deposited to a thickness of 20 to 100 nm on a base film such as a biaxially oriented PET film, a biaxially oriented nylon film (ONy film), or a biaxially oriented polypropylene film (OPP film) can be used as the barrier layer 785. Alternatively, a saponified ethylene-vinyl acetate copolymer (hereinafter sometimes referred to as EVOH) film, a biaxially oriented nylon MXD6 film, a polyacrylonitrile film, or a PET film, ONy film, or OPP film provided with a coating layer of polyvinylidene chloride can be used.

[0096] Such a barrier layer 785 is usually preferably laminated on the inner surface of the paper base layer 782 in order to effectively utilize its barrier properties, but when a metal foil such as aluminum or a metal-deposited film is used for the barrier layer 785, the metallic feel can also be utilized in the design, so that it can also be laminated on the outer surface of the paper base layer 782. The barrier layer 785 can be easily laminated by known dry lamination or extrusion lamination (sandwich lamination), etc.

[0097] The layer structure of the laminated sheet 78 of the blank plate 10 of the chuckable paper container 90 of this embodiment is exemplified below. Cross-sectional views of the laminated sheet 78 are shown in Figures 13A, 13B, and 13C.

[0098] 13A shows one embodiment of the layer structure of a laminated sheet 78 of blank plates 10 of a resealable paper container 90 of this embodiment, and is a cross-sectional view of a laminated sheet 78 of four blank plates 10. The layer structure is as follows. (Outer surface) Outermost thermoplastic resin layer 781 / Paper base protective layer 788 / Intermediate adhesive layer 784 / Paper base layer 782 / Innermost thermoplastic resin layer 783 (Inner surface)

[0099] Here, the surface on which patterns, characters, various codes, etc. are printed will be described. Although not shown, the surface to be printed (the outer or inner surface of the layer) may be the outer surface of the outermost thermoplastic resin layer 781, the outer or inner surface of the paper base protective layer 788, or the outer surface of the paper base layer 782. In any case, the layer on the outer side of the surface to be printed is transparent. Yes It is desirable to do so.

[0100] 13B shows another aspect of the layer structure of the laminated sheet 78 of the blank plates 10 of the resealable paper container 90 of this embodiment, and is a cross-sectional view of the laminated sheet 78 of the blank plates 10 consisting of five layers. The layer structure is as follows. (Outer surface) Paper base protective layer 788 / Intermediate adhesive layer 784 / Paper base layer 782 / Innermost thermoplastic resin layer 783 (inner surface) This layer structure includes an outermost thermoplastic resin layer 781 added to the outermost layer of the four-layered blank plate 10 shown in FIG. 13A.

[0101] The surface on which printing is performed in this embodiment will be described. Although not shown in the figure, the surface to be printed (the outer or inner surface of the layer) may be the outer or inner surface of the paper base protective layer 788 or the outer surface of the paper base layer 782. In either case, the layer on the outer side of the surface to be printed is transparent. Yes It is desirable to do so.

[0102] Furthermore, when the blank plate 10 is required to have barrier properties (water vapor, oxygen, aroma retention, etc.), it can be provided with a barrier layer 785. Fig. 5C shows yet another embodiment of the layer structure of the laminated sheet 78 of the blank plate 10 of the retractable paper container 90 of this embodiment, and is a cross-sectional view of the laminated sheet 78 of the blank plate 10 consisting of six layers, and the layer structure is as follows. (Outer surface) Paper base protective layer 788 / Intermediate adhesive layer 784 / Paper base layer 782 / Intermediate adhesive layer 784 / Barrier layer 785 / Innermost thermoplastic resin layer 783 (Inner side)

[0103] The surface on which printing is performed in this embodiment will be described. Although not shown in the figure, the surface to be printed (the outer or inner surface of the layer) may be the outer or inner surface of the paper base protective layer 788 or the outer surface of the paper base layer 782. In either case, the layer on the outer side of the surface to be printed is transparent. Yes It is desirable to do so.

[0104] The layers of the laminated sheets 78 are bonded together by known methods such as dry lamination, extrusion coating, adhesives, etc. Note that layers for bonding the layers together may not be shown if they are thin.

[0105] <Preparation of paper container with zipper> Below is an overview of the steps taken to create an intermediate stage paper container with a zipper (flat state) 91 from a blank plate 10 for a paper container with a zipper 90, to create an intermediate stage paper container with a zipper (box-assembled state) 92, and finally to complete a package of paper container with a zipper 90 filled with the contents.

[0106] <Creating a paper container with a zipper (flat state) at the intermediate stage> When the two blank sheets 10 described above are overlapped, a zipper tape 61 having a male zipper tape 61m and a female zipper tape 61f previously fitted together is inserted into the position where the zipper tape joints 52 overlap, and the outer surfaces of each of the two blank sheets 10 are heated and pressurized to heat seal the zipper tape joints 52.

[0107] Next, the inner surfaces of the upper seal portion 53 are heat-sealed, and the inner surfaces of the seal margins 36 of the side edges adjacent to the side edge portion 11 of the blank plate 10 are heat-sealed. Then, the intermediate stage paper container with a zipper (in a flat state) 91 is formed into a bag shape with the lower edge portion 26 open.

[0108] Also, a notch 77 may be provided at each end (at the points contacting the side edges on both sides) of the easy-open processing line 51. The notch 77 may be provided at either one of the ends.

[0109] The actual production of the zippered paper container 90 is not particularly limited, but in order to improve productivity, a machine may be used that performs in-line assembly of the paper container, filling of the contents, and sealing of each joint.

[0110] In this device, a long printed laminated sheet 78 wound up in a roll can be unwound, and in a format in which the paper containers are connected horizontally, processing of folding lines, insertion and heat sealing of zipper tape 61, heat sealing of side edge seal portions 36, heat sealing of upper seal portion 53, punching of notches 77, etc. can be performed.

[0111] It should be noted that the order of the steps may be different from that described above, so long as the desired paper container 90 with a zipper can be obtained.

[0112] 15A and 15B are enlarged cross-sectional views of the joining portion of the zipper tape 61, where the zipper tape 61 and the blank plate 10 are joined in the zippered paper container (flat state) 91 at an intermediate stage. The cut portion is shown at the cross-sectional position CC in Fig. 7. Here, the blank plate 10 is exemplified by the four-layer laminated sheet 78 in Fig. 13A.

[0113] 15A, a female zipper tape 61f is joined to a front blank plate 10b as a front zipper tape 61b. The female zipper tape 61f includes a female zipper tape body portion 62f joined to the blank plate 10 and a female zipper tape fitting portion 63f having a recess that fits with the male zipper tape 61m. In addition, a male zipper tape 61m is joined to the back blank plate 10a as the back zipper tape 61a. The male zipper tape 61m includes a male zipper tape body portion 62m joined to the blank plate 10 and a male zipper tape fitting portion 63m having a protrusion that fits with the female zipper tape 61f.

[0114] 15B, a male zipper tape 61m is joined to a front blank plate 10b as a front zipper tape 61b. The male zipper tape 61m includes a male zipper tape body portion 62m joined to the blank plate 10 and a male zipper tape fitting portion 63m having a protrusion that fits with a female zipper tape 61f. In addition, a female zipper tape 61f is joined to the back blank plate 10a as the back zipper tape 61a. The female zipper tape 61f includes a female zipper tape body portion 62f joined to the blank plate 10 and a female zipper tape fitting portion 63f having a recess that fits with the male zipper tape 61m.

[0115] In addition, whether the male zipper tape 61m or the female zipper tape 61f is joined to the front blank plate 10b is selected appropriately depending on the required performance of the paper container 90 with a zipper and the specifications of the manufacturing equipment for the paper container 90 with a zipper.

[0116] The zipper tape 61 has a particularly thick zipper tape fitting portion 63, and when the folding portion 76 of the top protrusion 74 is folded, the blank plate 10 is prone to damage (cracks) at the position of the zipper tape fitting portion 63.

[0117] <Creating a paper container with a zipper (in an erected state) at the intermediate stage> A mandrel is inserted through the opening of the bottom 73 of this intermediate stage zippered paper container (flat state) 91, leaving the upper overlapping plate 34, and the lower top plate 33 is spread out front to back by the first horizontal fold line 22, and the upper overlapping plate 34 is stood upright.

[0118] Here, in order to ensure that the ridge portion 72d of the body portion 72 is bent, an auxiliary member may be brought into contact with the vicinity (including abutment) of the ridge portion 72d from the inner side and / or the outer side of the body portion 72.

[0119] Below the upper overlapping plate 34, a top portion 71 formed by the top plate 33 and a flat body portion 72 are formed, and a zippered paper container (standing state) 92 in the intermediate stage is formed in which the bottom portion 73 opens in a substantially rectangular shape. At this stage, the upper overlapping plate 34 stands upright as shown in FIG. 8.

[0120] In addition, in the design, the horizontal cross-sectional shape of the body 72 and the shape of the opening of the bottom 73 are assumed to be rectangular, but because the zippered paper container 90 is made of a flexible laminated sheet 78 mainly made of paper, they are made approximately rectangular, even if they are not completely rectangular.

[0121] <Forming and filling of paper containers with zippers> Next, the upper overlapping plate 34 that stands upward is folded toward the back side (the back top panel 33a side) and laid down, and the top side protrusions 74 that protrude on both the left and right sides are folded toward the side panel 32 and joined to the body 72. At this time, the folding portion 76 of the top side protrusion 74 is folded, and in order to ensure that the folding process of the top side protrusion folding line 15 of the top side 71 is performed, an auxiliary member may be brought into contact with the vicinity (including abutment) of the top side protrusion folding line 15 from the inner and / or outer side of the top side 71.

[0122] The method of joining the top protrusion 74 to the body 72 may be a method using an adhesive (hot melt, etc.), a method using an adhesive tape, a method of mechanical joining (engagement, use of a joining tool), etc. Also, when a thermoplastic resin layer (sealant layer) is provided on the outermost layer of the blank plate 10, a method of heat sealing the thermoplastic resin layer (sealant layer) may be used. A similar method is used for joining the bottom side protrusion 75 described later.

[0123] In addition, the tip of the top side protrusion 74 may be joined to the body 72 of the paper container 90 with a zipper. Also, a portion of the top-side protruding portion 74 other than the tip may be joined to the body portion 72 of the resealable paper container 90. In that case, the tip of the top-side protruding portion 74 does not need to be joined to the body portion 72 of the resealable paper container 90.

[0124] The bottom 73 of the intermediate stage zippered paper container (standing state) 92 formed as described above is turned upward, and the contents are filled through the open bottom 73, and then the bottom 73 is folded and the bottom side seal portions 37 are heat sealed together in a palm-to-palm seal format.

[0125] Then, the joined bottom side seal portion 37 is folded toward the back side (toward the back side bottom panel 35a) and laid down, and the bottom side protrusions 75 protruding from both the left and right sides are folded toward the bottom panel 35 and joined, thereby completing the packaging body of the approximately rectangular shaped zippered paper container 90.

[0126] Fig. 9 is a perspective view showing a chuck paper container 90 of this embodiment. Fig. 10 is a side view of the chuck paper container 90 shown in Fig. 9. Fig. 11 is a plan view of the chuck paper container 90 shown in Fig. 9.

[0127] The zipper-equipped paper container 90 shown in FIG. 9 has an outer shape formed into a substantially rectangular parallelepiped shape, and its body 72 has a ridge portion 72d. In addition, since the paper container 90 with a zipper is made of a flexible laminated sheet 78 mainly made of paper, it does not have a perfect rectangular parallelepiped shape, so it is made approximately rectangular parallelepiped.

[0128] The function and effect of the paper base material protective layer 788 in the folded portion 76 of the top protruding portion 74 of the zippered paper container 90 of this embodiment will be described. An enlarged cross-sectional view of the bent portion 76 of the top-side protruding portion 74 is shown in Fig. 14. The cross-sectional position is the cross-sectional position BB shown in Fig. 11. The front blank sheet 10b and the back blank sheet 10a shown in Fig. 14 are the three-layer laminated sheet 78 shown in Fig. 13A.

[0129] When the top protrusion 74 is bent to be joined to the body 72, the front blank sheet 10b at the bent portion 76 of the top protrusion 74 is stretched. Here, a tensile load is also applied to the paper base protective layer 788, which has a property of being difficult to stretch due to the stretching process, but the paper base protective layer 788 is hardly stretched. This makes it possible to suppress the stretching of the paper base layer 782 laminated on the inner side of the paper base protective layer 788, and prevents damage (cracks) from occurring in the paper base layer 782.

[0130] The paper base protective layer 788 and the paper base layer 782 may be directly laminated to each other, or one or more layers may be interposed between them as long as the effect of the paper base protective layer 788 in suppressing the elongation of the paper base layer 782 is not impaired.

[0131] A paper base material protective layer 788 is always provided on the front blank plate 10b, where damage (cracks) are likely to occur at the bent portion 76 of the top protrusion 74. In this case, the back blank board 10a does not need to be provided with the paper base material protective layer 788. In this case, the cost of the blank board 10 can be reduced because the paper base material protective layer 788 is omitted.

[0132] Alternatively, the back blank board 10a may be provided with a paper base material protective layer 788. In this case, the front blank board 10b and the back blank board 10a have the same surface appearance (texture), resulting in excellent appearance. Furthermore, since only one type of laminated sheet 78 is required for the blank board 10, the manufacturing process of the laminated sheet 78 is easily managed, and the materials can be easily arranged and managed.

[0133] <Opening operation for removing paper containers with zippers> FIG. 12 shows the completed package of the resealable paper container 90 containing the contents with the top portion 71 opened to allow the contents to be removed.

[0134] The easy-open processing line 51 is opened by hand from a notch 77 provided on one side edge 11 (here the right side) and is cut all the way to the other side edge 11 (here the left side).

[0135] Next, the front side opening grip area 57b between the front side easy-open processing line 51b and the front side zipper tape 61b, and the back side opening grip area 57a between the back side easy-open processing line 51a and the back side zipper tape 61a are each grasped with a human hand and spread out toward the outside of the zippered paper container 90, thereby opening the zipper tape 61 exposed at the easy-open processing line 51.

[0136] During this opening operation of the zipper tape 61, the ends of the zipper tape 61 on the side edge portion 11 side of each blank sheet 10 are opened over substantially the entire width up to the seal margins 36 on each side edge portion. As described above, the male zipper tape 61m and the female zipper tape 61f of the zipper tape 61 are separated from each other, whereby the removal opening 56 is formed. EXAMPLES

[0137] The embodiments of the present disclosure will be described more specifically below with reference to examples.

[0138] <Example 1> In Example 1, a paper container 90 with a zipper having the configuration shown in FIG. 9 was produced using the blank plate 10 of FIG. 6A and FIG. 6B corresponding to the first embodiment.

[0139] Two blank sheets 10 shown in Fig. 6A and Fig. 6B were prepared, and the inner surfaces of the blank sheets 10 were aligned and overlapped, and the side edge seal portions 36 of the opposing sides were heat-sealed as shown in Fig. 7, and the upper seal portion 53 was also heat-sealed. At the same time, the zipper tape 61 was also heat-sealed. In this way, a paper container with a zipper (in a flat state) 91 in the intermediate stage in which the bottom seal portion 37 was not sealed was produced.

[0140] The laminated sheet 78 of the blank plate 10 had the following structure: Fig. 13A shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer surface) Paper base protective layer 788 (oriented PET film 12μm T4102 Toyobo) / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Printed layer (gravure printing on the outer surface of the paper base layer 782) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0141] A method for producing the laminated sheet 78 will now be described. First, a roll of paper base layer 782 was unwound, and predetermined patterns and characters were gravure printed at predetermined positions, and the paper base layer was then wound up again into a roll.

[0142] In the next step, the above-mentioned rolled paper base layer 782 was unwound, and a paper base protective layer 788 (stretched PET film, 12 μm) was laminated on the outer surface of the paper base layer 782 by extrusion lamination (sandwich lamination) with a molten intermediate adhesive layer 784 (LDPE, 15 μm) interposed therebetween.

[0143] Next, an innermost thermoplastic resin layer 783 (LDPE 30 μm) was formed on the inner surface of the paper base layer 782 by extrusion lamination. Next, the laminated sheet 78 formed by the above-mentioned processing was wound up into a roll.

[0144] In order to improve the bonding strength between the bonding layers, anchor coat treatment, corona treatment, flame treatment, etc. may be performed as necessary. Alternatively, ozone treatment may be performed on the molten resin.

[0145] Next, the roll-shaped laminated sheet 78 is unwound and subjected to processes such as scoring and punching, thereby completing the blank plate 10.

[0146] The zipper tape 61 that is heat-sealed and attached to the inner surface of the upper overlapping plate 34 and the top side plate 41 of the zipper-equipped paper container 90 has a two-layer structure in which the zipper tape body 62 that is heat-sealed is made up of both the male zipper tape 61m and the female zipper tape 61f. The zipper tape 61 has a resin layer formed of LLDPE on the side to be heat sealed to the zippered paper container 90, and a resin layer formed of MDPE on the opposite side. The male zipper tape fitting portion 63m and the female zipper tape fitting portion 63f are both formed of LLDPE, and the zipper tape bodies 62 each have a width of 7 mm.

[0147] The rear blank plate 10a and the front blank plate 10b are rectangular, measuring 220 mm in length and 169 mm in width, and have side edge seal margins 36 of 7 mm width provided on the side edges 11 on both sides as seal margins at the peripheral edges. Additionally, a bottom seal margin 37 having a width of 10 mm was provided on each of the lower edges 26 of the lower side. Further, a seal margin of an upper seal portion 53 having a width of 3 mm was provided near the upper edge portion 21 of the upper overlapping plate 34 and the side plate 41 of the top portion.

[0148] The blank plate 10 is provided with an upper overlapping plate 34, a first horizontal folding line 22, a top plate 33, a second horizontal folding line 23, a wall plate 31, a third horizontal folding line 24, and a bottom plate 35, in that order from the upper edge 21 downward.

[0149] Additionally, on both outer sides of the upper overlapping plate 34, top side plates 41 are provided via the second vertical folding lines 13.

[0150] Additionally, a top side protrusion margin 38 is provided on the outer side of both sides of the top panel 33 via the second vertical folding line 13.

[0151] In addition, side panels 32 are provided on the outside of both sides of the wall panel 31 via second vertical folding lines 13.

[0152] In addition, bottom side protrusion margins 43 are provided on the outer sides of both sides of the bottom panel 35 via second vertical folding lines 13.

[0153] An easy-open processing line 51 is provided on the upper overlapping plate 34 and the top side plate 41 at a position 10 mm below the upper edge 21 which becomes the upper edge when the inner faces of the two blank plates 10 are aligned and overlapped, as shown in Fig. 7, in the transverse direction of the top 71 of the zippered paper container 90, together with printing on the paper base layer 782 of the laminated sheet 78. The easy-open processing line 51 is provided as an intermittent half-cut line.

[0154] In addition, below the easy-open processing line 51, a zipper tape 61 is heat-sealed to the inner surface of the upper overlapping plate 34 and the side plate 41 of the top part with a gap of 5 mm in a direction crossing the top part 71 of the zippered paper container 90.

[0155] In addition, after joining two blank sheets 10, heat sealing the zipper tape 61, heat sealing the side edge seal portion 36, and heat sealing the upper seal portion 53 in the above-mentioned manner, a notch 77 was provided on the right side edge portion 11 of the overlapping easy-open processing line 51, and a zippered paper container (flat state) 91 in the intermediate stage was produced with the bottom seal portion 37 in an unsealed state (see FIG. 7).

[0156] Next, a mandrel was inserted through the opening of the unsealed bottom side seal 37 of this intermediate stage zippered paper container (flat state) 91, leaving the upper overlapping plate 34, and the lower top plate 33 was spread out front to back by the first horizontal fold line 22, and the upper overlapping plate 34 was stood upright. A top portion 71 formed by the top plate 33 was formed under the upper overlapping plate 34, followed by a body portion 72 having a substantially rectangular horizontal cross section (a plane substantially parallel to the bottom surface), and a paper container with a zipper (standing state) 92 in the intermediate stage was formed with a bottom portion 73 opening in a substantially rectangular shape (see FIG. 8).

[0157] Then, the overlapped upper overlapping plate 34 was bent toward the rear top panel 33a. After that, the top protrusions 74 connected to both the left and right sides of the top 71 were joined to the body 72. Hot melt was used for the joining. In addition, the tip of the top protrusion 74 is folded toward the inside of the zippered paper container 90 (downward before the top protrusion 74 is folded) to make it easier to join the top protrusion 74 and the body 72.

[0158] When the top-side protrusion 74 is joined to the body 72, the angle between the top 71 and the top-side protrusion 74 via the bent portion 76 of the top-side protrusion 74 is set to be approximately a right angle.

[0159] The completed paper container had a roughly rectangular parallelepiped shape with dimensions of 95 mm width, 120 mm height, and 60 mm depth. In the manner described above, a paper container 90 with a zipper was produced.

[0160] <Example 2> In this embodiment, the position of the printed layer such as a design in the laminated sheet 78 of the blank board 10 was different from that in the first embodiment.

[0161] The laminated sheet 78 of the blank plate 10 of this embodiment has the following structure: Fig. 13A shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer surface) Paper base protective layer 788 (oriented PET film 12μm T4102 Toyobo) / Printed layer (gravure printing on the inner surface of the paper base protective layer 788) / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0162] A method for producing the laminated sheet 78 will now be described. First, a roll of paper base protective layer 788 (stretched PET film 12 μm) was unwound, and predetermined patterns and characters were gravure printed at predetermined positions on the inner surface of the paper base protective layer 788, and then the paper base protective layer was wound up again into a roll.

[0163] In the next step, a roll-shaped paper base layer 782 was unwound, and the printed surface of the above-mentioned printed paper base protective layer 788 was laminated to the outer surface of the paper base layer 782 by extrusion lamination (sandwich lamination) with a molten intermediate adhesive layer 784 (LDPE 15 μm) interposed therebetween.

[0164] Next, an innermost thermoplastic resin layer 783 (LDPE 30 μm) was formed on the inner surface of the paper base layer 782 by extrusion lamination. Next, the laminated sheet 78 formed by the above-mentioned processing was wound up into a roll.

[0165] Next, the roll-shaped laminated sheet 78 is unwound and subjected to processes such as scoring and punching, thereby completing the blank plate 10.

[0166] Other layer configurations of the laminated sheet 78 of the blank plate 10 and the shape of the blank plate 10 were the same as in Example 1. Furthermore, the manufacturing method from the blank plate 10 to the retractable paper container 90 was also the same as in Example 1.

[0167] <Example 3> In this embodiment, the material of the paper base protective layer 788 of the laminated sheet 78 of the blank plate 10 was different from that in the second embodiment.

[0168] The laminated sheet 78 of the blank plate 10 of this embodiment has the following structure: Fig. 13A shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer surface) Paper base protective layer 788 (oriented polypropylene film 20μm P-2171 Toyobo) / Printed layer (gravure printing on the inner surface of the paper base protective layer 788) / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0169] The position and shape of the printed layer such as a pattern on the blank plate 10 were the same as in Example 2. The manufacturing method from the blank plate 10 to the chuck-equipped paper container 90 was also the same as in Example 2.

[0170] <Example 4> The feature of this embodiment is that laminate sheet 78 has thermoplastic resin layer 781 on the outermost surface, which provides moisture resistance and stain resistance against the outside world. When top-side protruding portion 74 is folded and joined to body portion 72, and when bottom-side protruding portion 75 is folded and joined to bottom portion 73, the thermoplastic resin layer 781 on the outermost surface of the relevant portion can be heat-sealed by thermally melting it. In this case, no hot melt is required.

[0171] In this embodiment, the laminated sheet 78 of the blank plate 10 has the following structure: Fig. 13B shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer surface) Outermost thermoplastic resin layer 781 (LDPE 20μm LC520 Nippon Polyethylene) / Paper base protective layer 788 (oriented PET film 12μm T4102 Toyobo) / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Printed layer (gravure printing on the outer surface of the paper base layer 782) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 40μm LC520 Nippon Polyethylene) (Inner side)

[0172] A method for producing the laminated sheet 78 will now be described. First, a roll of paper base layer 782 was unwound, and predetermined patterns and characters were gravure printed at predetermined positions, and the paper base layer was then wound up again into a roll.

[0173] In the next step, the above-mentioned rolled paper base layer 782 was unwound, and a paper base protective layer 788 (stretched PET film, 12 μm) was laminated on the outer surface of the paper base layer 782 by extrusion lamination (sandwich lamination) with a molten intermediate adhesive layer 784 (LDPE, 15 μm) interposed therebetween.

[0174] In the next step, a paper base protective layer 788 (oriented PET film, 12 μm) was formed on the outer surface, and an outermost thermoplastic resin layer 781 (LDPE, 20 μm) was formed by extrusion lamination.

[0175] In the next step, an innermost thermoplastic resin layer 783 (LDPE 30 μm) was formed on the inner surface of the paper base layer 782 by extrusion lamination. Next, the laminated sheet 78 formed by the above-mentioned processing was wound up into a roll.

[0176] Next, the roll-shaped laminated sheet 78 is unwound and subjected to processes such as scoring and punching, thereby completing the blank plate 10.

[0177] Otherwise, the shape of the blank plate 10 was the same as in Example 1. In addition, the manufacturing method for the blank plate 10 to the chuck-equipped paper container 90 was also the same as in Example 1.

[0178] <Example 5> In this embodiment, the material of the paper base protective layer 788 of the laminated sheet 78 of the blank plate 10 was different from that in the fourth embodiment.

[0179] In this embodiment, the laminated sheet 78 of the blank plate 10 has the following structure: Fig. 13B shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer side) Outermost thermoplastic resin layer 781 (LDPE 20μm LC520 Nippon Polyethylene) / Paper base protective layer 788 (oriented nylon film 15μm emblem ON Unitika / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Printed layer (gravure printing on the outer surface of the paper base layer 782) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 40μm LC520 Nippon Polyethylene) (Inner side)

[0180] Other than that, the position of the printed layer such as a pattern of the laminated sheet 78 of the blank plate 10, the layer structure, the printing method, and the lamination method were the same as those in Example 4. The shape of the blank plate 10 was also the same as that in Example 4. Furthermore, the manufacturing method from the blank plate 10 to the chuck-equipped paper container 90 was also the same as that in Example 4.

[0181] <Example 6> In this embodiment, the position of the printed layer such as a design in the laminated sheet 78 of the blank board 10 was different from that in the fourth embodiment.

[0182] In this embodiment, the laminated sheet 78 of the blank plate 10 has the following structure: Fig. 13B shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer side) Outermost thermoplastic resin layer 781 (LDPE 20μm LC520 Nippon Polyethylene) / Paper base protective layer 788 (oriented PET film 12μm T4102 Toyobo) / Printed layer (gravure printing on the inner surface of the paper base protective layer 788) / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 40μm LC520 Nippon Polyethylene) (Inner side)

[0183] A method for producing the laminated sheet 78 will now be described. First, a roll of paper base protective layer 788 (stretched PET film 12 μm) was unwound, and predetermined patterns and characters were gravure printed at predetermined positions on the inner surface of the paper base protective layer 788, and then the paper base protective layer was wound up again into a roll.

[0184] In the next step, a roll-shaped paper base layer 782 was unwound, and the printed surface of the above-mentioned printed paper base protective layer 788 was laminated to the outer surface of the paper base layer 782 by extrusion lamination (sandwich lamination) with a molten intermediate adhesive layer 784 (LDPE 15 μm) interposed therebetween.

[0185] In the next step, a paper base protective layer 788 (oriented PET film, 12 μm) was formed on the outer surface, and an outermost thermoplastic resin layer 781 (LDPE, 20 μm) was formed by extrusion lamination.

[0186] In the next step, an innermost thermoplastic resin layer 783 (LDPE 30 μm) was formed on the inner surface of the paper base layer 782 by extrusion lamination. Next, the laminated sheet 78 formed by the above-mentioned processing was wound up into a roll.

[0187] In the next step, the rolled laminated sheet 78 is unwound and subjected to processes such as creasing and punching, thereby completing the blank plate 10.

[0188] Other than that, the shape of the blank plate 10 was the same as in Example 4. Furthermore, the manufacturing method from the blank plate 10 to the retractable paper container 90 was also the same as in Example 4.

[0189] <Example 7> In this example, the position of the printed layer such as a pattern in the laminated sheet 78 of the blank plate 10 was different from that in Examples 4 and 6. The other layer configurations, shapes, and manufacturing method from the blank plate 10 were the same as in Example 4.

[0190] In this embodiment, the laminated sheet 78 of the blank plate 10 has the following structure: Fig. 13B shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer side) Printed layer (gravure printing on the outer surface of the outermost thermoplastic resin layer 781) / Outermost thermoplastic resin layer 781 (LDPE 20μm LC520 Nippon Polyethylene) / Paper base protective layer 788 (oriented PET film 12μm T4102 Toyobo) / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 40μm LC520 Nippon Polyethylene) (Inner side)

[0191] A method for producing the laminated sheet 78 will now be described. First, a roll-shaped paper base layer 782 was unwound, and a paper base protective layer 788 was laminated on the outer surface of the paper base layer 782 by extrusion lamination (sandwich lamination) with a molten intermediate adhesive layer 784 (LDPE 15 μm) interposed therebetween.

[0192] In the next step, a paper base protective layer 788 (oriented PET film, 12 μm) was formed on the outer surface, and an outermost thermoplastic resin layer 781 (LDPE, 20 μm) was formed by extrusion lamination.

[0193] In the next step, a laminate sheet 78 having an innermost thermoplastic resin layer 783 (LDPE 30 μm) formed on the inner surface of the paper base layer 782 by extrusion lamination was wound up into a roll.

[0194] In the next process, the laminate sheet 78 was unwound, and predetermined patterns and characters were gravure printed at predetermined positions on the outer surface of the outermost thermoplastic resin layer 781 (LDPE 20 μm) of the laminate sheet 78, and then the laminate sheet 78 was wound up into a roll again.

[0195] In the next step, the printed laminated sheet 78 in roll form is unwound and subjected to processes such as creasing and punching, thereby completing the blank plate 10.

[0196] Other than that, the shape of the blank plate 10 was the same as in Example 4. Furthermore, the manufacturing method from the blank plate 10 to the retractable paper container 90 was also the same as in Example 4.

[0197] <Example 8> In this embodiment, a barrier layer 785 is provided to impart oxygen barrier properties to the laminated sheet 78.

[0198] In this embodiment, the laminated sheet 78 of the blank board 10 has the following structure: Fig. 13C shows a cross-sectional view of the laminated sheet 78, but the printed layer such as a pattern is not shown. (Outer surface) Paper base protective layer 788 (oriented PET film 12μm T4102 Toyobo) / Intermediate adhesive layer 784 (LDPE 15μm LC520 Japanese polyethylene) / Printed layer (gravure printing on the outer surface of the paper base layer 782) / Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / Intermediate adhesive layer 784 (EMAA 20μm Mitsui Dow Polychemical N0908N) / Barrier layer 785 (silica-deposited PET 12μm Dai Nippon Printing IB-PET-UBP) / The innermost thermoplastic resin layer 783 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0199] A method for producing the laminated sheet 78 will now be described. First, a roll of paper base layer 782 was unwound, and predetermined patterns and characters were gravure printed at predetermined positions, and the paper base layer was then wound up again into a roll.

[0200] In the next step, the above-mentioned rolled paper base layer 782 was unwound, and a paper base protective layer 788 (stretched PET film, 12 μm) was laminated on the outer surface of the paper base layer 782 by extrusion lamination (sandwich lamination) with a molten intermediate adhesive layer 784 (LDPE, 15 μm) interposed therebetween.

[0201] In the next step, an innermost thermoplastic resin layer 783 (LDPE 30 μm) was formed on the inner surface of the paper base layer 782 by extrusion lamination. Next, the laminated sheet formed by the above processing was wound up into a roll.

[0202] In the next step, the above-mentioned rolled laminate sheet was unwound, and a barrier layer 785 (silica-deposited PET 12 μm) was laminated to the inner surface of the paper base layer 782 by extrusion lamination (sandwich lamination) with a molten intermediate adhesive layer 784 (EMAA 20 μm) interposed therebetween.

[0203] In the next step, an innermost thermoplastic resin layer 783 (LDPE 30 μm) was formed on the inner surface of the barrier layer 785 by extrusion lamination. Next, the laminated sheet 78 formed by the above-mentioned processing was wound up into a roll.

[0204] In the next step, the rolled laminated sheet 78 is unwound and subjected to processes such as creasing and punching, thereby completing the blank plate 10.

[0205] Other than that, the shape of the blank plate 10 was the same as in Example 1. Furthermore, the manufacturing method from the blank plate 10 to the retractable paper container 90 was also the same as in Example 1.

[0206] <Comparative Example 1> In this comparative example, the laminated sheet 88 of the blank board 81 had the following configuration: Fig. 5B shows a cross-sectional view of the laminated sheet 88, but the printed layer such as a pattern is not shown. (Outer side) Printed layer (gravure printing on the outer surface of the paper base layer 882) / Paper base layer 882 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 883 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0207] The manufacturing method of the laminated sheet 88 described above is the same as the manufacturing method of Example 1 except that the lamination of the paper base protective layer 788 and the intermediate adhesive layer 784 is omitted.

[0208] <Comparative Example 2> In this comparative example, the laminated sheet 88 of the blank plate 81 had the following configuration: Fig. 5A shows a cross-sectional view of the laminated sheet 88, but the printed layer such as a pattern is not shown. (Outer side) Outermost thermoplastic resin layer 881 (LDPE 20μm LC520 Nippon Polyethylene) Printed layer (gravure printing on the outer surface of the paper base layer 882) / Paper base layer 882 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 883 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0209] The manufacturing method of the laminated sheet 88 is the same as the manufacturing method of Comparative Example 1, except that the outermost thermoplastic resin layer 881 is laminated. The method of laminating the outermost thermoplastic resin layer 881 is the same as the method described in Example 4.

[0210] <Comparative Example 3> In this comparative example, the position of the printed layer such as a pattern in the laminated sheet 78 of the blank plate 10 was different from that in comparative example 2. The other layer configurations, shapes, and manufacturing method from the blank plate 81 were the same as in comparative example 2. In this comparative example, the laminated sheet 78 of the blank board 10 had the following configuration: Fig. 5A shows a cross-sectional view of the laminated sheet 88, but the printed layer such as a pattern is not shown. (Outer side) Printed layer (gravure printing on the outer surface of the outermost thermoplastic resin layer 781) / Outermost thermoplastic resin layer 781 (LDPE 20μm LC520 Nippon Polyethylene) Paper base layer 782 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / The innermost thermoplastic resin layer 783 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0211] The manufacturing method of the laminated sheet 88 described above is the same as that of the seventh embodiment except that the lamination of the paper base protective layer 788 and the intermediate adhesive layer 784 is omitted.

[0212] <Comparative Example 4> This comparative example was the same as comparative example 1, except that a barrier layer 885 was provided in laminated sheet 88 of blank plate 81 to impart oxygen barrier properties, and an intermediate adhesive layer 884 was further provided to laminate barrier layer 885. The other layer configurations, shapes, and manufacturing method from blank plate 81 were the same as comparative example 1.

[0213] In this comparative example, the laminated sheet 88 of the blank board 81 had the following configuration: Fig. 5D shows a cross-sectional view of the laminated sheet 88, but the printed layer such as a pattern is not shown. (Outer surface) Printed layer (gravure printing on the outer surface of the paper base layer 882) / Paper base layer 882 (base paper for liquid paper containers 150g / m 2 Nippon Paper Industries) / Intermediate adhesive layer 884 (EMAA 20μm Mitsui Dow Polychemical N0908N) / Barrier layer 885 (silica-deposited PET 12μm Dai Nippon Printing IB-PET-UBP) / The innermost thermoplastic resin layer 883 (LDPE 30μm LC520 Nippon Polyethylene) (Inner side)

[0214] The manufacturing method of the laminated sheet 88 described above is the same as that of the eighth embodiment except that the lamination of the paper base protective layer 788 and the intermediate adhesive layer 784 is omitted. <Evaluation> Fifty samples each of Examples 1 to 8 and Comparative Examples 1 to 4 were produced.

[0215] In Comparative Examples 1 to 4, damage (cracks) 879 occurred in the laminated sheet 88 at the folded portion 876 of the protruding portion 874 on the top side of the zipper-equipped paper container 80. In Comparative Examples 2 and 3, a polyethylene layer was provided on the outside of the paper base layer 882 as the outermost thermoplastic resin layer 781, but a crack (damage) 879 occurred.

[0216] This is because the tensile strength and tensile modulus of the material of the paper base protective layer 788 of the present disclosure are greater than those of polyethylene. The tensile strength and tensile modulus can be measured according to the following standards, such as JIS K7161-1:2014, JIS K7172:1999, JIS K6922-2:2018, and JIS C2318:2020.

[0217] In all of Examples 1 to 8, no deterioration in appearance due to damage (cracks) or the like occurred in the laminated sheet 78 of the folded portion 76 of the top protruding portion 74 of the zipper-equipped paper container 90. When the top side protrusions 74 connected to both the left and right sides of the top 71 of the resealable paper container 90 are joined to the body 72 of the resealable paper container 90, the paper base material layer 782 of the laminated sheet 78 of the folded portion 76 of the top side protrusions 74 is protected by a paper base material protective layer 788 provided on one of the outer layers. Therefore, the folded portion 76 of the top side protrusions 74 of the paper base material layer 782 is not significantly stretched, and damage (cracks) is unlikely to occur.

[0218] The intermediate-stage zippered paper containers (standing state) 92 of Examples 1 to 8 prepared as described above were filled with snack foods as the contents from the bottom 73, and then the bottom 73 was folded in and the bottom side seal portions 37 were heat sealed, and the heat-sealed portion was laid down toward the rear side bottom panel 35a.

[0219] Furthermore, the bottom side protrusions 75 protruding from both the left and right sides of the bottom 73 were folded toward the bottom panel 35 and joined to the front side bottom panel 35b and / or the front side bottom side seal portion 37b to produce a package of the approximately rectangular shaped zippered paper container 90 of Examples 1 to 8.

[0220] In addition, the packages of the resealable paper containers 90 of Examples 1 to 8 prepared as described above were tested for their ease of opening, suitability for removing the contents, and resealability with the resealable zipper.

[0221] As a result, in both cases, the notch 77 provided on the side plate 41 of the top portion as an initial opening means, and the easy-to-open processing line 51 provided on the upper overlapping plate 34 and the side plate 41 of the top portion made it easy to cut off the upper part of the easy-to-open processing line 51 and open the package.

[0222] Next, the front side opening grip area 57b between the front side easy-open processing line 51b and the front side zipper tape 61b, and the back side opening grip area 57a between the back side easy-open processing line 51a and the back side zipper tape 61a, were each grasped with a human hand and spread out toward the outside of the zippered paper container 90.

[0223] As a result, the zipper tape 61 exposed at the easy-open processing line 51 was easily released, and the top of the zippered paper container 90 was opened over almost the entire width, forming a removal opening 56. Through the removal opening 56, the snack food filled inside could be easily removed.

[0224] In addition, after removing a portion of the contents, the packages of the resealable paper containers 90 of Examples 1 to 8 were easily resealed by reattaching the zipper tape 61. The remaining contents were then properly preserved.

[0225] Furthermore, in the retractable paper container 90 of the present disclosure, the mass ratio of paper to the total mass of the retractable paper container 90 fully satisfied the standard for a paper container of 51% by mass or more. [Explanation of symbols]

[0226] 10 Blank Board 10a Back blank plate 10b Front blank plate 11 Side edge 12 First vertical fold line 13 Second vertical fold line 14 Second vertical fold imaginary line 15. Top protruding part fold line 17 Top diagonal fold line 18 Bottom diagonal fold line 21 Upper edge 22 First horizontal fold line 23 Second horizontal fold line 24 Third horizontal fold line 25 Fourth horizontal fold line 26 Lower edge 31 Wall Panel 32 Side plate 33 Top plate 34 Upper overlapping plate 35 Bottom plate 36 Side edge seal allowance 37 Bottom seal 38 Top protruding part 41 Side plate of the top 43 Bottom side protrusion allowance 51 Easy-open processed wire 52 Zipper tape joint 53 Upper seal part 56 Removal opening 57 Opening grip 61 Zipper Tape 61m Male Zipper Tape 61f Female zipper tape 62 Zipper Tape Body 62m Male zipper tape body 62f Female zipper tape body 63 Zipper tape fitting 63m Male zipper tape fitting 63f Female zipper tape fitting 71 Top of zippered paper container 72 Body of a paper container with a zipper 72d Ridge of the torso 73 Bottom of zippered paper container 74 Top protrusion 75 Bottom protrusion 76 Bend of top protruding part 77 Notch 78 Laminated Sheet 781 Outermost thermoplastic resin layer 782 Paper base layer 783 Innermost thermoplastic resin layer 784 Intermediate adhesive layer 785 Barrier Layer 788 Paper base protective layer 80 Conventional paper container with zipper 81 Prior art blank plate 81a Back blank plate of the prior art 81b Prior art front blank plate 812 First vertical folding line of the prior art 821 Prior art intermediate horizontal fold line (half fold line) 831 Prior art wall panels 832 Side plate of the prior art 833 Conventional top panel 834 Prior art upper overlapping plate 835 Prior art bottom plate 836 Side edge seal of the conventional technology 837 Bottom seal of conventional technology 838 Top protrusion of conventional technology 843 Side plate of the top part of the prior art 851 Prior art easy-open processing line 856 Prior art removal opening 861 Prior art zipper tape 871 Top of a paper container with a zipper according to the prior art 872 Body of a paper container with a zipper according to the prior art 873 Bottom of a zippered paper container of the prior art 874 Top protrusion of conventional technology 876 Bending part of the top protrusion of the conventional technology 88 Laminated sheet of paper container of the prior art 881 Outermost thermoplastic resin layer of conventional technology 882 Prior art paper base layer 883 Thermoplastic resin layer of the innermost layer of the conventional technology 884 Prior art intermediate adhesive layer 885 Prior Art Barrier Layer 90 The zippered paper container of the present disclosure 91 Paper container with a zipper in the intermediate stage of the present disclosure (flat state) 92 Paper container with a zipper in the intermediate stage of the present disclosure (in a raised state) A: Cutting position of a cross-sectional view of the folded part of the protruding part on the top side of a paper container with a zipper according to the prior art B: Cutting position of a cross-sectional view of the folded portion of the protruding portion on the top side of the zipper-equipped paper container of the present disclosure C Cutting position of the enlarged cross-sectional view of the zipper tape joint E First top intersection (intersection of the first vertical fold line and the first horizontal fold line) F Second top intersection (intersection of the second vertical fold line and the second horizontal fold line) G First bottom intersection (intersection of the first vertical fold line and the fourth horizontal fold line) H Second bottom intersection (intersection of the second vertical fold line and the third horizontal fold line)

Claims

1. In a paper container with a zipper, a blank plate made of a laminated sheet including a paper base layer is assembled, The blank plate includes two front blank plates and a back blank plate having folding lines; A top part including an upper overlapping plate formed by overlapping and joining the front blank plate and the back blank plate to the top of the zipper-equipped paper container, and a top plate connected to the lower side of the upper overlapping plate; A top side plate connected to both left and right sides of the upper overlapping plate; A top portion protruding portion provided on both the left and right sides of the top portion; A body portion provided below the top portion; A bottom portion provided on the lower side of the body portion; An upper seal portion that crosses the upper edge portions or the vicinity of the upper edge portions of the upper overlapping plate and the side plate of the top portion; A zipper tape is provided below the upper seal portion and crosses the upper overlapping plate and the side plate of the top portion, A paper container with a zipper, wherein at least the outermost layer of the laminated sheet of the front blank plate is provided with a paper base material protective layer made of a stretched film.

2. The paper container with a zipper according to claim 1 , wherein the paper base protective layer is a stretched polyethylene terephthalate film.

3. The paper container with a zipper according to claim 1 , wherein the paper base protective layer is a stretched nylon film.

4. The paper container with a zipper according to claim 1 , wherein the paper base material protective layer is a stretched polypropylene film.

5. The paper container with a zipper according to any one of claims 1 to 4, wherein the paper base material protective layer has a thickness of 20 µm or more and 200 µm or less.

6. A printed layer such as a pattern is provided on the outer surface of the paper base layer, The paper container with a zipper according to any one of claims 1 to 5, wherein the paper base material protective layer is see-through.

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