Paper container, paper container with lid member and blank material

Abstract

To provide a paper container, a paper container with a lid member, and a blank material, which can improve a degree of freedom of a manufacturing condition.SOLUTION: A paper container 10 includes: a bottom portion 21; a plurality of side portions 23 connected to the bottom portion 21 through a first fold line 22; a paper container 20 having a plurality of flange pieces 25 each connected to each side portion 23 through a second fold line 24; and a formed film 40 laminated on a surface of a paper container 20. The side portions 23 are adjacent to each other without being continuous with each other. A heat seal layer is provided on at least part of the surface of the paper container 20.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a paper container, a paper container with a lid, and a blank. [Background technology]

[0002] Containers for containing food and drink to be taken home (so-called take-out products) or food and drink to be delivered to home delivery have been known.

[0003] In recent years, in order to address the problem of marine pollution and reduce the environmental load, there has been a demand for reducing the amount of resin used in such containers, and efforts are being made to reduce the amount of resin and change the materials used in the containers. As such a container, a paper container comprising a paper container and a formed film laminated on the inner wall of the paper container is known (for example, Patent Document 1). In such a paper container, after the food is filled, the paper container is covered with a lid material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2013-545675 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of such a paper container, when the paper container and a molded film laminated on the paper container are bonded to each other, there may be restrictions on the resins that can be used for the molded film.

[0006] In addition, with such paper containers, it can be difficult to partially change the adhesive strength between the paper container and the molded film laminated on the paper container, or to adhere the molded film to only a portion of the paper container.

[0007] The present disclosure has been made in consideration of these points, and aims to provide a paper container, a paper container with a lid, and a blank material that enable greater freedom in manufacturing conditions. [Means for solving the problem]

[0008] A paper container according to one embodiment comprises a paper container having a bottom, a plurality of side portions connected to the bottom via a first fold line, and a plurality of flange pieces connected to each side portion via a second fold line, and a molded film laminated on a surface of the paper container, wherein the side portions are adjacent to each other without being continuous with each other, and a heat seal layer is provided on at least a portion of the surface of the paper container.

[0009] In one embodiment of the paper container, the heat seal layer may be provided on the flange piece.

[0010] In one embodiment of the paper container, the weight per unit area of ​​the heat seal layer provided on the flange piece is 0.1 g / m 2 More than 10.0g / m 2 It may be the following.

[0011] In one embodiment of the paper container, the heat seal layer may be provided on the bottom along the periphery of the bottom.

[0012] In one embodiment of the paper container, the heat seal layer may be provided on the bottom and the side so as to span the first fold line.

[0013] In one embodiment of a paper container, the heat seal layer is provided on the bottom, the sides and the flange pieces, and the weight per unit area of ​​the heat seal layer provided on the flange pieces is greater than the weight per unit area of ​​the heat seal layer provided on the sides, and the weight per unit area of ​​the heat seal layer provided on the sides is greater than the weight per unit area of ​​the heat seal layer provided on the bottom.

[0014] A paper container with a lid according to one embodiment is a paper container with a lid comprising the paper container according to the present disclosure and a lid that seals the paper container.

[0015] A blank material according to one embodiment comprises a bottom panel, a plurality of side panels connected to the bottom panel via a first fold line, and a plurality of flange piece panels connected to each of the side panels via a second fold line, with gaps formed between the side panels, and a heat seal layer provided on at least a portion of the surface.

[0016] In one embodiment of the blank, the heat seal layer may be provided on the flange piece panel.

[0017] In one embodiment of the blank, the weight per unit area of ​​the heat seal layer provided on the flange piece panel is 0.1 g / m 2 More than 10.0g / m 2 It may be the following.

[0018] In one embodiment of the blank, the heat seal layer may be provided on the bottom panel along a periphery of the bottom panel.

[0019] In one embodiment of the blank, the heat seal layer may be provided on the bottom panel and on the side panels so as to straddle the first fold line.

[0020] In one embodiment of the blank material, the heat seal layer is provided on the bottom panel, the side panels and the flange piece panels, and the weight per unit area of ​​the heat seal layer provided on the flange piece panels is greater than the weight per unit area of ​​the heat seal layer provided on the side panels, and the weight per unit area of ​​the heat seal layer provided on the side panels is greater than the weight per unit area of ​​the heat seal layer provided on the bottom panel. Effect of the Invention

[0021] According to the present disclosure, it is possible to improve the freedom of manufacturing conditions for paper containers and paper containers with lids. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a paper container with a lid according to this embodiment. [Diagram 2] FIG. 2 is a perspective view showing a paper container according to the present embodiment. [Diagram 3] FIG. 3 is a plan view showing the paper container according to the present embodiment. [Figure 4] FIG. 4 is a development view showing a blank for producing a paper container according to this embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing a method for manufacturing a paper container according to this embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a method for manufacturing a paper container according to this embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a method for manufacturing a paper container according to this embodiment. [Figure 8] FIG. 8 is a perspective view showing a first modified example of the paper container according to the present embodiment. [Figure 9] FIG. 9 is a development view showing a blank for producing a first modified example of a paper container according to the present embodiment. [Figure 10]FIG. 10 is a perspective view showing a second modified example of the paper container according to the present embodiment. [Figure 11] FIG. 11 is a development view showing a blank for producing a second modified example of a paper container according to the present embodiment. [Figure 12] FIG. 12 is a perspective view showing a third modified example of the paper container according to the present embodiment. [Figure 13] FIG. 13 is a development view showing a blank for producing a third modified example of a paper container according to the present embodiment. [Figure 14] FIG. 14 is a development view showing another example of a blank for producing the third modified example of the paper container according to the present embodiment. [Figure 15] FIG. 15 is a development view showing another example of a blank for producing the third modified example of the paper container according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present embodiment will be described below with reference to the drawings. FIGS. 1 to 7 are diagrams showing the present embodiment. Each of the following figures is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, the present invention can be modified appropriately without departing from the technical concept. In each of the following figures, the same parts are given the same reference numerals, and some detailed explanations may be omitted. In addition, the numerical values ​​such as the dimensions of each member and the material names described in this specification are examples of the embodiment, and are not limited to these, and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are intended to include substantially the same state in addition to their strict meanings. In this specification, "upper" and "lower" refer to the upper and lower sides of the paper container in an upright state (FIG. 1), respectively. In this specification, "surface" refers to the surface facing the contents, or the surface that faces upward when the paper container is upright.

[0024] Paper container with lid As shown in Fig. 1, a paper container with a lid 1 according to this embodiment comprises a paper container 10 and a lid 50 that seals the paper container 10. First, the paper container 10 will be described.

[0025] Paper containers 1 to 3, the paper container 10 includes a paper container 20 and a formed film 40 laminated on the surface of the paper container 20. The paper container 20 is produced by assembling blanks 30, which will be described later.

[0026] (Paper container) The paper container 20 has a bottom 21, a plurality of side portions 23 connected to the bottom 21 via fold lines (first fold lines) 22, and a plurality of flange pieces 25 connected to each of the side portions 23 via fold lines (second fold lines) 24.

[0027] The bottom 21 has a generally rectangular shape in plan view. The bottom 21 may have a polygonal shape, such as an octagonal shape, in plan view.

[0028] The fold line (first fold line) 22 connecting the bottom portion 21 and the side portion 23 may be formed in a perforated shape or a half-cut line. This makes it easier to fold the side portion 23 relative to the bottom portion 21. When the fold line 22 is formed in a perforated shape, the formed film 40 is pressed against the paper container 20 in the vicinity of the fold line 22 by sucking air through suction holes 61 of a cavity side die 60 described below. This improves the adhesion between the formed film 40 and the paper container 20.

[0029] Each side portion 23 extends upward from the bottom portion 21. In the illustrated example, the paper container 20 has four side portions 23, and the side portions 23 are formed in an inverted quadrangular pyramid shape as a whole. However, this is not limited thereto, and the side portions 23 may be formed in a polygonal pyramid shape, such as an inverted octagonal pyramid shape as a whole.

[0030] The multiple side portions 23 are adjacent to each other without being continuous with each other. That is, the side portions 23 are adjacent to each other without overlapping each other. This improves the adhesion between the side portions 23 and the molded film 40 over the entire circumference of the paper container 20. In addition, since the side portions 23 are adjacent to each other without overlapping each other, it is possible to suppress the occurrence of pinholes and the like in the molded film 40 when the molded film 40 is bonded to the paper container 20. Note that a minute gap is formed between each side portion 23 for air to pass through, and the molded film 40 is configured to be pressed against the paper container 20 by sucking air from a suction hole 61 of a cavity side mold 60 described later.

[0031] The fold line (second fold line) 24 connecting the side portion 23 and the flange piece 25 may be formed in a perforated shape, similar to the fold line 22, or may be a half-cut line. This makes it easier to fold the flange piece 25 relative to the side portion 23. When the fold line 24 is formed in a perforated shape, the formed film 40 is pressed against the paper container 20 in the vicinity of the fold line 24 by sucking air through suction holes 61 of the cavity side mold 60 described below. This improves the adhesion between the formed film 40 and the paper container 20.

[0032] Each flange piece 25 protrudes horizontally toward a side from an upper end of the side portion 23. In the illustrated example, the paper container 20 has four flange pieces 25, and the flange pieces 25 are formed in an overall annular shape.

[0033] The flange pieces 25 are adjacent to each other without being continuous with each other. That is, the flange pieces 25 are adjacent to each other without overlapping each other. This allows the adhesion between the flange pieces 25 and the molded film 40 to be improved over the entire circumference of the paper container 20. In addition, since the flange pieces 25 are adjacent to each other without overlapping each other, it is possible to prevent pinholes and the like from occurring in the molded film 40 when the molded film 40 is bonded to the paper container 20. Furthermore, since the flange pieces 25 are adjacent to each other without overlapping each other, it is possible to improve the adhesion between the molded film 40 and the lid material 50 when sealing the lid material 50 in the area of ​​the molded film 40 of the paper container 10 corresponding to the flange pieces 25. This allows the occurrence of sealing defects of the lid material 50 to be prevented. In addition, in this specification, "adjacent" includes a case where adjacent members (for example, flange pieces 25) are in contact with each other without any gaps over the entire circumference, as well as a case that falls under the following (1) or (2). (1) A component and another component are adjacent to each other with only a portion of the component in contact with the other component. (2) When a first component and another component are adjacent to each other without being in contact with each other, at least a portion of the gap between the first component and the other component is large enough that the molded film 40 (film 40a described below) cannot enter when the molded film 40 is adhered to the first component and the other component.

[0034] Next, the adhesive strength between the paper container 20 and the formed film 40 will be described.

[0035] The adhesive strength between the bottom 21 and the formed film 40 and the adhesive strength between the side portion 23 and the formed film 40 may be 0.05 N / 15 mm or more and 0.4 N / 15 mm or less, respectively. By having these adhesive strengths of 0.05 N / 15 mm or more, it is possible to prevent the formed film 40 from being unintentionally peeled off from the paper container 20. In particular, it is possible to prevent the formed film 40 from being unintentionally peeled off from the bottom 21 or the side portion 23 of the paper container 20 when removing the lid material 50 from the paper container 10 of the lid material-attached paper container 1. In addition, by having these adhesive strengths of 0.4 N / 15 mm or less, it is possible to easily separate the paper container 20 and the formed film 40 when recycling the paper container 20. Note that the adhesive strength between the bottom 21 and the formed film 40 and the adhesive strength between the side portion 23 and the formed film 40 may be different from each other. For example, the adhesive strength between the side portion 23 and the molded film 40 may be greater than the adhesive strength between the bottom portion 21 and the molded film 40. The adhesive strength can be measured in accordance with JIS Z 0238:1998 by performing a 90° peel test on a sample cut into a 15 mm wide rectangular shape at a peel speed of 50 mm / min using a tensile tester (for example, Tensilon universal material testing machine: RTC1310A, manufactured by Orientec Co., Ltd.).

[0036] The adhesive strength between the flange piece 25 and the molded film 40 may be 1.0 N / 15 mm or more. This makes it possible to prevent the molded film 40 from peeling off from the flange piece 25 when the lid material 50 is removed from the paper container 10. This makes it possible to prevent the ease of opening the lid material 50 from decreasing.

[0037] Furthermore, the adhesive strength between the flange piece 25 and the molded film 40 may be 5.0 N / 15 mm or less. This can prevent the molded film 40 from becoming difficult to peel off from the paper container 20 when recycling the paper container 20. In this case, it is acceptable for the paper container 20 from which the molded film 40 has been peeled off to have paper peeling (part of the paper container peeling off).

[0038] Here, a heat seal agent may be applied to at least a part of the surface of the paper container 20 (the surface of the blank material 30 described later). This allows the adhesive strength between the paper container 20 and the formed film 40 to be easily adjusted. Therefore, the desired adhesive strength can be easily obtained. In this embodiment, a heat seal layer H is provided on the flange piece 25 (flange piece panel 35 described later). This heat seal layer H is formed by applying a heat seal agent to the flange piece 25 (flange piece panel 35 described later). The heat seal agent may be ink. As the heat seal agent, one containing ethylene-vinyl acetate copolymer (EVA), ionomer, polyethylene (PE) or polypropylene (PP) can be used. In addition, as the heat seal agent, vinyl-based, acrylic-based, polyamide-based, polyester-based, polyether-based, polyurethane-based, epoxy-based, chlorinated EVA-based, chlorinated PP-based, vinyl chloride-vinyl acetate-based, polyol-based, polyethyleneimine-based, starch-based, nitrocellulose-based, rubber-based resin, etc. may be included. Furthermore, the heat seal agent may be applied onto the flange piece 25 (the flange piece panel 35 described later) by gravure printing, flexographic printing, offset printing, etc. In FIG. 2 and other figures, the area where the heat seal layer H is provided is indicated by hatching.

[0039] The weight per unit area of ​​the heat seal layer H (i.e., the amount of heat sealant applied to the flange piece 25 (the flange piece panel 35 described later)) is 0.1 g / m 2 More than 10.0g / m 2 The amount of heat sealant applied to the flange piece 25 (the flange piece panel 35 described later) may be 0.1 g / m or less. 2 As a result, the adhesive strength between the flange piece 25 and the molded film 40 can be easily increased to a desired strength. This makes it possible to prevent the molded film 40 from peeling off from the flange piece 25 when removing the lid material 50 from the paper container 10, and to prevent a decrease in the ease of opening the lid material 50. In addition, when the amount of heat sealant applied to the flange piece 25 (the flange piece panel 35 described later) is 10.0 g / m2 By satisfying the above condition, it is possible to prevent the adhesive strength between the flange piece 25 and the molded film 40 from becoming too large. This makes it possible to prevent the molded film 40 from becoming difficult to peel off from the paper container 20 when recycling the paper container 20.

[0040] (Blank material) Next, a blank 30 for producing the paper container 20 will be described. As shown in Fig. 4, the blank 30 includes a bottom panel 31, a plurality of side panels 33 connected to the bottom panel 31 via a first fold line 32, and a plurality of flange piece panels 35 connected to each of the side panels 33 via a second fold line 34. In the illustrated example, the blank 30 includes four side panels 33 and four flange piece panels 35. The bottom panel 31, the first fold line 32, the side panel 33, the second fold line 34, and the flange piece panel 35 of the blank 30 correspond to the bottom 21, the fold line (first fold line) 22, the side 23, the fold line (second fold line) 24, and the flange piece 25 of the paper container 20, respectively.

[0041] The bottom panel 31, the side panel 33 and the flange piece panel 35 of the blank 30 are integrally formed. Such a blank 30 can be produced by subjecting the paper material that constitutes the blank 30 to a punching process or the like.

[0042] Also, a gap 36 is formed between the side panels 33. In this case, each side panel 33 is formed in a trapezoidal shape. Also, each side panel 33 has a pair of side edges 33a extending from the bottom panel 31. And a gap 36 is formed between the side edges 33a of the side panels 33. As a result, in the above-mentioned paper container 10, the side portions 23 do not overlap each other but are adjacent to each other (see Figs. 2 and 3). In the illustrated example, in each side panel 33, the pair of side edges 33a extend in a direction away from each other as they move from the first fold line 32 side toward the second fold line 34 side.

[0043] The paper material constituting such a blank 30 is, for example, a paper having a basis weight of 150 g / m 2 More than 600g / m 2 The following types of paperboard, coated paper, card paper, ivory paper, milk carton base paper, cup base paper, coated cardboard, and other processed papers can be used.

[0044] (Formed film) Next, the molded film 40 will be described with reference to Fig. 1 to Fig. 3. This molded film 40 plays a role in protecting the paper container 20. In addition, the molded film 40 has a container shape and covers the entire surface of the paper container 20. This prevents the contents filled in the paper container 10 from leaking out of the paper container 10. The molded film 40 is adhered to the paper container 20 by, for example, heat sealing (thermal welding).

[0045] Such a molded film 40 may be a film made of a thermoplastic resin having water resistance, sealing property, and heat fusion property. For example, various types of polyethylene (PE), polypropylene (PP), polyvinyl chloride, polyethylene terephthalate (PET), ethylene-vinyl acetate copolymer, ionomer, ethylene-acrylic acid copolymer, polyamide, polyvinylidene chloride, polystyrene, saponified ethylene-vinyl acetate copolymer, polycarbonate, polybutene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer (EVOH), and other various thermoplastic resin films can be used alone or in a laminated state. In particular, when gas barrier properties are to be imparted to the paper container 10, a laminate having a gas barrier material such as ethylene-vinyl alcohol copolymer (EVOH) laminated on the intermediate layer, specifically, a laminate having a layer structure such as PE / EVOH / PE, PP / EVOH / PE, or A (amorphous)·PET / EVOH / PE can be used.

[0046] Formed film 40 may be made from a laminate having the following layer configuration, for example: (Outside) Polyethylene (40μm) / Ionomer (40μm) / Polyethylene (40μm) (Inside) (Outside) Polypropylene (30 μm) / Adhesive layer (10 μm) / Ionomer (40 μm) / Adhesive layer (10 μm) / Polypropylene (30 μm) (Inside) (Outside) Polyethylene (20μm) / Ionomer (30μm) / Adhesive layer (10μm) / Ethylene-vinyl alcohol copolymer (10μm) / Adhesive layer (10μm) / Ionomer (15μm) / Ethylene-vinyl acetate copolymer (20μm) (Inside)

[0047] Each of the above layers is formed according to a conventional method, such as dry lamination, extrusion lamination, extrusion coating, or other coating method.

[0048] Lid material Next, a description will be given of the lid member 50. The lid member 50 is sealed to the forming film 40 of the paper container 10 in an area corresponding to the flange piece 25 over the entire periphery.

[0049] The lid material 50 may be, for example, a laminate having a layer structure such as PET / sealant, oriented nylon (ONY) / sealant, PET / oriented nylon (ONY) / sealant, PET / PE / sealant, or K-coated oriented nylon (KONY) / PE / sealant. The laminate constituting the lid material 50 may be, for example, a laminate having a gas barrier material such as ethylene-vinyl alcohol copolymer (EVOH) laminated in an intermediate layer. The lid material 50 may be, for example, a laminate having a layer structure such as PET / PE / ethylene-vinyl alcohol copolymer (EVOH) / PE / sealant.

[0050] The lid material 50 may be made, for example, from a laminate having the following layer configuration. (Outside) Polyethylene terephthalate film with transparent vapor deposition layer (12 μm) / Nylon film (15 μm) / Polyethylene film (40 μm) (Inside)

[0051] It is preferable to use a resin material capable of exhibiting so-called easy peel properties for the laminate constituting the lid material 50. Each of the above layers is formed according to a conventional method, such as a dry lamination method, an extrusion lamination method, an extrusion coating method, or another coating method.

[0052] In the paper container 1 with a lid material having such a configuration, first, the contents are filled into the paper container 10. Next, the lid material 50 is sealed to the region of the forming film 40 of the paper container 10 that corresponds to the flange piece 25. This results in a paper container 1 with a lid material filled with the contents. The paper container 1 with a lid material may be a container for chilled or frozen foods, or may be used as a take-out container. The contents may also be food such as prepared dishes, meat, and dairy products.

[0053] Next, the operation of the present embodiment having such a configuration will be described. Here, a method for manufacturing the paper container 10 and a method for manufacturing the paper container 1 with a lid material will be described with reference to Figs.

[0054] Manufacturing method of paper container First, the blank material 30 is prepared. In this process, a paper material is first prepared, and a heat seal agent is applied to a predetermined position of the paper material. The heat seal agent may be applied by gravure printing, flexographic printing, offset printing, or the like. In this way, a heat seal layer H is provided at a predetermined position of the paper material. Next, the paper material is punched out by a laser or the like to obtain the blank material 30.

[0055] Next, as shown in Fig. 5, the blank 30 is attached to a cavity-side mold 60. A suction hole 61 is formed in this cavity-side mold 60, and the blank 30 is attached to the cavity-side mold 60 by sucking air through the suction hole 61. At this time, the side panel 33 of the blank 30 is folded relative to the bottom panel 31 along the first fold line 32. Similarly, the flange piece panel 35 of the blank 30 is folded relative to the side panel 33 along the second fold line 34. In this way, the paper container 20 attached to the cavity-side mold 60 is obtained.

[0056] Next, the molded film 40 is laminated on the surface of the paper container 20. At this time, first, as shown in FIG. 6, the film 40a constituting the molded film 40 is placed above the paper container 20. Next, the film 40a is heated by the core side mold 62 (see FIG. 7). Then, after the film 40a has been sufficiently heated by the core side mold 62, air is sucked through the suction holes 61. As a result, the film 40a is sucked onto the paper container 20. At this time, the core side mold 62 also presses the film 40a against the paper container 20. As a result, the film 40a is in close contact with the paper container 20.

[0057] Thereafter, the film 40a is cut into a desired shape by a cutting mechanism 63 provided in the core side mold 62. This results in a formed film 40 laminated on a paper container 20, as shown in Fig. 7. In this manner, the paper container 10 is obtained.

[0058] In parallel with the production of the paper container 10, the lid material 50 is prepared. At this time, a predetermined laminate is produced by a dry lamination method or the like. Then, the laminate is punched into a predetermined shape with a blade or the like to produce the lid material 50.

[0059] Next, the paper container 10 is filled with the contents, and the paper container 10 is sealed with the lid 50. At this time, the paper container 10 is first filled with the contents (not shown). Next, the lid 50 is placed on the forming film 40 at a position corresponding to the flange piece 25.

[0060] Next, the lid material 50 is sealed to the formed film 40 by a sealing hot plate (not shown) or the like. At this time, the air inside the paper container 10 may be replaced by, for example, nitrogen gas or the like.

[0061] In this manner, a paper container with lid 1 is obtained, which comprises the paper container 10 and the lid 50 that seals the paper container 10.

[0062] As described above, according to this embodiment, the heat seal agent is applied to at least a part of the surface of the paper container 20. This allows the adhesive strength between the paper container 20 and the formed film 40 to be easily adjusted. Therefore, there are no restrictions on the resin used for the formed film 40. In addition, by applying the heat seal agent to at least a part of the surface of the paper container 20, it is possible to partially change the adhesive strength between the paper container 20 and the formed film 40, or to adhere the formed film 40 to only a part of the paper container 20. This improves the degree of freedom in manufacturing conditions. In addition, since the adhesive strength between the paper container 20 and the formed film 40 can be easily adjusted, the desired adhesive strength can be easily obtained.

[0063] In addition, since the desired adhesive strength can be easily obtained, the formed film 40 can be prevented from peeling off unintentionally from the paper container 20, and the airtightness of the paper container 1 with the lid material can be improved. That is, if the formed film 40 is peeled off unintentionally from the paper container 20, the paper container 20 may not be able to maintain its shape as a container, and the paper container 20 may buckle. In this case, an unintentional force may be applied to the lid material 50 and the formed film 40, and the lid material 50 may be unintentionally removed from the paper container 10. In contrast, in this embodiment, the formed film 40 can be prevented from peeling off unintentionally from the paper container 20, and the lid material 50 can be prevented from being unintentionally removed from the paper container 10. This improves the airtightness of the paper container 1 with the lid material. Therefore, the barrier property of the paper container 1 with the lid material can be improved, and the life of the contents can be extended. As a result, food loss can be reduced.

[0064] Furthermore, according to this embodiment, a heat sealant is applied onto the flange piece 25. This makes it possible to easily adjust the adhesive strength between the flange piece 25 and the molded film 40. This makes it possible to prevent the molded film 40 from peeling off from the flange piece 25 when removing the lid material 50 from the paper container 10 of the lid-attached paper container 1. As a result, it is possible to prevent the ease of opening the lid material 50 from decreasing.

[0065] Modifications of paper containers Next, modified examples of the paper container 10 according to the present embodiment will be described with reference to Figures 8 to 15. In Figures 8 to 15, the same parts as those in the embodiment shown in Figures 1 to 7 are given the same reference numerals and detailed descriptions thereof will be omitted.

[0066] (First modified example of paper container) In the above-described embodiment, an example in which the heat seal layer H is provided on the flange piece 25 (flange piece panel 35) has been described, but the present invention is not limited to this. For example, as shown in FIG. 8, the heat seal layer H may be provided along the periphery of the bottom 21 (i.e., the fold line 22). That is, the heat seal agent may be applied onto the bottom 21 along the periphery of the bottom 21 (i.e., the fold line 22). In this case, as shown in FIG. 9, in the blank material 30, the heat seal layer H may be provided along the periphery of the bottom panel 31 (i.e., the first fold line 32). That is, in the blank material 30, the heat seal agent may be applied onto the bottom panel 31 along the periphery of the bottom panel 31 (i.e., the first fold line 32).

[0067] Here, gaps are likely to form between the paper container 20 and the forming film 40 near the peripheral edge of the bottom 21. For this reason, there is a possibility that the forming film 40 will unintentionally peel off from the paper container 20, starting from the peripheral edge of the bottom 21.

[0068] In contrast, by applying a heat sealant onto the bottom 21 along the periphery of the bottom 21, it is possible to increase the adhesive strength between the paper container 20 and the formed film 40 in the vicinity of the periphery of the bottom 21. This makes it possible to prevent the formed film 40 from unintentionally peeling off from the paper container 20.

[0069] In this case, the amount of heat sealant applied to the bottom 21 (bottom panel 31) is 0.1 g / m 2 More than 10.0g / m 2 The amount of the heat seal agent applied to the bottom 21 (bottom panel 31) may be 0.1 g / m or less. 2 By satisfying the above, the adhesive strength between the bottom 21 and the molded film 40 can be easily increased to a desired strength. This makes it possible to prevent the molded film 40 from unintentionally peeling off from the paper container 20. In addition, when the amount of heat seal agent applied to the bottom 21 (bottom panel 31) is 10.0 g / m 2 By satisfying the condition below, it is possible to prevent the adhesive strength between the bottom 21 and the molded film 40 from becoming too large. This makes it possible to prevent the molded film 40 from becoming difficult to peel off from the paper container 20 when recycling the paper container 20.

[0070] (Second modified example of paper container)

[0071] Also, as shown in FIG. 10, the heat seal layer H may be provided on the bottom 21 and the side 23 so as to straddle the fold line 22. That is, the heat seal agent may be applied to the bottom 21 and the side 23 so as to straddle the fold line 22. In this case, as shown in FIG. 11, in the blank 30, the heat seal layer H may be provided on the bottom panel 31 and the side panel 33 so as to straddle the first fold line 32. That is, in the blank 30, the heat seal agent may be applied on the bottom panel 31 and the side panel 33 so as to straddle the first fold line 32. Even in this case, the adhesive strength between the paper container 20 and the forming film 40 can be increased in the vicinity of the periphery of the bottom 21 (i.e., the fold line 22). Therefore, it is possible to suppress the forming film 40 from being unintentionally peeled off from the paper container 20.

[0072] In this case, the amount of heat sealant applied on the bottom 21 (bottom panel 31) and / or the side 23 (side panel 33) is 0.1 g / m 2 More than 10.0g / m 2 The amount of heat sealant applied on the bottom portion 21 (bottom panel 31) and / or the side portion 23 (side panel 33) may be 0.1 g / m or less. 2 By satisfying the above, the adhesive strength between the bottom 21 and / or side 23 and the molded film 40 can be easily increased to a desired strength. This makes it possible to prevent the molded film 40 from unintentionally peeling off from the paper container 20. In addition, when the amount of heat seal agent applied onto the bottom 21 (bottom panel 31) and / or side 23 (side panel 33) is 10.0 g / m 2 By satisfying the above condition, it is possible to prevent the adhesive strength between the bottom portion 21 and / or the side portion 23 and the molded film 40 from becoming too high. This makes it possible to prevent the molded film 40 from becoming difficult to separate from the paper container 20 when recycling the paper container 20.

[0073] (Third modified example of paper container)

[0074] Furthermore, as shown in FIG. 12, the heat seal layer H may be provided on the bottom 21, the side 23, and the flange piece 25. That is, the heat seal agent may be applied on the bottom 21, the side 23, and the flange piece 25. In the illustrated example, the heat seal agent is applied to the entire surface of the paper container 20. In addition, the weight per unit area of ​​the heat seal layer H provided on the flange piece 25 may be greater than the weight per unit area of ​​the heat seal layer H provided on the side 23. That is, the amount of heat seal agent applied on the flange piece 25 may be greater than the amount of heat seal agent applied on the side 23. Furthermore, the weight per unit area of ​​the heat seal layer H provided on the side 23 may be greater than the weight per unit area of ​​the heat seal layer H provided on the bottom 21. That is, the amount of heat seal agent applied on the side 23 may be greater than the amount of heat seal agent applied on the bottom 21.

[0075] In this case, as shown in FIG. 13, in the blank 30, the heat seal agent may be applied on the bottom panel 31, the side panel 33, and the flange piece panel 35. In the illustrated example, the heat seal agent is applied to the entire surface of the blank 30. The weight per unit area of ​​the heat seal layer H provided on the flange piece panel 35 may be greater than the weight per unit area of ​​the heat seal layer H provided on the side panel 33. That is, the amount of heat seal agent applied on the flange piece panel 35 may be greater than the amount of heat seal agent applied on the side panel 33. The weight per unit area of ​​the heat seal layer H provided on the side panel 33 may be greater than the weight per unit area of ​​the heat seal layer H provided on the bottom panel 31. That is, the amount of heat seal agent applied on the side panel 33 may be greater than the amount of heat seal agent applied on the bottom panel 31.

[0076] According to this modification, in the paper container 10, it is possible to easily adjust the adhesive strength between the paper container 20 and the formed film 40. Therefore, it is possible to easily obtain a desired adhesive strength.

[0077] Here, in order to improve the ease of opening the lid material 50, it is preferable to increase the adhesive strength between the flange piece 25 and the molded film 40. On the other hand, in order to improve the recyclability of the paper container 20, it is preferable to reduce the adhesive strength between the side portion 23 and the molded film 40 and the adhesive strength between the bottom portion 21 and the molded film 40. However, if the adhesive strength between the side portion 23 and the molded film 40 and the adhesive strength between the bottom portion 21 and the molded film 40 are reduced, there is a possibility that the molded film 40 will unintentionally peel off from the bottom portion 21 or the side portion 23 of the paper container 20 when removing the lid material 50 from the paper container 10. In particular, if the adhesive strength between the side portion 23 and the molded film 40 is reduced, the molded film 40 will be easily peeled off from the paper container 20 starting from the portion of the molded film 40 that is adhered to the side portion 23 when removing the lid material 50 from the paper container 10. Therefore, in order to improve the openability of the lid material 50 while improving the recyclability of the paper container 20, it is preferable to make the adhesive strength between the flange piece 25 and the molded film 40 greater than the adhesive strength between the side portion 23 and the molded film 40, and to make the adhesive strength between the side portion 23 and the molded film 40 greater than the adhesive strength between the bottom 21 and the molded film 40 so that the adhesive strength between the side portion 23 and the molded film 40 has a predetermined adhesive strength.

[0078] In this modification, the amount of heat sealant applied onto the flange piece 25 is greater than the amount of heat sealant applied onto the side portion 23, and the amount of heat sealant applied onto the side portion 23 is greater than the amount of heat sealant applied onto the bottom portion 21. Therefore, the adhesive strength between the flange piece 25 and the formed film 40 can be greater than the adhesive strength between the side portion 23 and the formed film 40, and the adhesive strength between the side portion 23 and the formed film 40 can be greater than the adhesive strength between the bottom portion 21 and the formed film 40. This makes it possible to prevent the formed film 40 from peeling off from the flange piece 25, the side portion 23, and the bottom portion 21 of the paper container 20 when removing the lid material 50 from the paper container 10. In addition, when recycling the paper container 20, the paper container 20 and the formed film 40 can be easily separated. Therefore, it is possible to prevent the ease of opening the lid material 50 from decreasing, and it is possible to easily separate the paper container 20 and the formed film 40 when recycling the paper container 20.

[0079] As shown in FIG. 14 and FIG. 15, the heat sealant may be applied to the entire surface of the blank material 30 in a predetermined pattern. For example, as shown in FIG. 14, the heat sealant may be applied to the surface of the blank material 30 so as to present a polka dot pattern. As shown in FIG. 15, the heat sealant may be applied to the surface of the blank material 30 in a striped pattern. The pattern shape of the heat sealant is not particularly limited. Although not shown, the heat sealant may be applied to the surface of the blank material 30 so that the area where the heat sealant is not applied presents a polka dot pattern. The heat sealant may be applied to the surface of the blank material 30 so as to present another pattern such as a checkered pattern, or may be applied to the surface of the blank material 30 in a lattice pattern. In this case, although not shown, the heat sealant is also applied to the entire surface of the paper container 20 produced from the blank material 30 in a predetermined pattern. The heat sealant may be applied to a part of the surface of the blank material 30 in a predetermined pattern.

[0080] (Fourth modified example of paper container) In the above embodiment, an example has been described in which the adhesive strength between the paper container 20 and the formed film 40 is adjusted by providing a heat seal layer H (applying a heat seal agent) on the surface of the paper container 20, but the present invention is not limited to this. For example, the adhesive strength may be further adjusted by changing the temperature at which the formed film 40 is heated. That is, if it is desired to increase the adhesive strength, the heating temperature of the formed film 40 may be increased. On the other hand, if it is desired to decrease the adhesive strength, the heating temperature of the formed film 40 may be decreased. Even in this case, the adhesive strength between the paper container 20 and the formed film 40 can be easily adjusted. Note that the adhesive strength between the paper container 20 and the formed film 40 may be adjusted by changing the pressure or time when the core side die 62 presses the film 40a against the paper container 20. EXAMPLES

[0081] Next, a specific example of the above embodiment will be described.

[0082] Example 1 First, the paper container 10 shown in Fig. 2 and Fig. 3 was produced. At this time, first, a paper material (coated paper) (manufactured by Mitsubishi Paper Mills, N Pearl Card (product name), basis weight 260 g / m) was used as the material for the paper container 20. 2 ) was prepared. Next, a heat seal agent containing an ethylene-vinyl acetate copolymer (Seikadyne 1900W, manufactured by Dainichiseika Chemicals Mfg. Co., Ltd.) was applied to the entire surface of the paper material by gravure printing. Also, a polyethylene film was prepared as a forming film 40. Next, a paper container 10 was produced by laminating the film on the surface of the paper material.

[0083] (1) Adhesion evaluation Next, an adhesiveness evaluation was performed to check whether the formed film 40 was adhered to the paper container 20 or not.

[0084] (2) Peelability evaluation test Next, a peelability evaluation test was conducted. In this test, the molded film 40 was peeled off from the paper container 20 of the paper container 10. Then, the ease of peeling off the molded film 40 was evaluated.

[0085] Example 2 Adhesion and peelability evaluation tests were carried out in the same manner as in Example 1, except that the heat sealant was applied only onto the flange piece panel 35 made of paper, as shown in FIG.

[0086] Example 3 Adhesion evaluation and peelability evaluation tests were carried out in the same manner as in Example 1, except that a heat sealing agent containing an ionomer (manufactured by Mitsui Chemicals, Inc., Chemipearl S500 (product name)) was used.

[0087] Example 4 Adhesion evaluation and peelability evaluation tests were carried out in the same manner as in Example 1, except that a heat sealant containing polyethylene (Arrowbase SD-1200 (product name) manufactured by Unitika Ltd.) was used.

[0088] Example 5 Adhesion evaluation and peelability evaluation tests were performed in the same manner as in Example 1, except that a heat sealing agent containing polyethylene (Arrowbase SD-1200 (product name) manufactured by Unitika Ltd.) was used and a polypropylene film was used as the molded film 40.

[0089] Example 6 The material of the paper container 20 is paper (uncoated paper) (manufactured by Oji F-Tex Co., Ltd., cup base paper, basis weight 220 g / m 2 The adhesion evaluation and peelability evaluation tests were carried out in the same manner as in Example 1, except that a heat sealant containing polyethylene (Arrowbase SD-1200 (product name) manufactured by Unitika Ltd.) was used.

[0090] Example 7 The material of the paper container 20 is paper (uncoated paper) (manufactured by Oji F-Tex Co., Ltd., cup base paper, basis weight 220 g / m 2Adhesion evaluation and peelability evaluation tests were performed in the same manner as in Example 1, except that a heat sealing agent containing polypropylene (Arrowbase DA-1010 (product name) manufactured by Unitika Ltd.) was used, and a polypropylene film was used as the molded film 40.

[0091] Example 8 The material of the paper container 20 was paper (coated cardboard) (manufactured by Oji Materia Co., Ltd., UF Coat (product name), basis weight 270 g / m 2 The adhesion evaluation and peelability evaluation tests were carried out in the same manner as in Example 1, except that a heat sealant containing polyethylene (Arrowbase SD-1200 (product name) manufactured by Unitika Ltd.) was used.

[0092] Example 9 The material of the paper container 20 was paper (coated cardboard) (manufactured by Oji Materia Co., Ltd., UF Coat (product name), basis weight 270 g / m 2 Adhesion evaluation and peelability evaluation tests were performed in the same manner as in Example 1, except that a heat sealing agent containing polypropylene (Arrowbase DA-1010 (product name) manufactured by Unitika Ltd.) was used, and a polypropylene film was used as the molded film 40.

[0093] Comparative Example 1 Adhesion evaluation and peelability evaluation tests were carried out in the same manner as in Example 1, except that no heat sealant was applied to the surface of the paper material.

[0094] Comparative Example 2 Adhesion evaluation and peelability evaluation tests were carried out in the same manner as in Example 1, except that no heat sealant was applied to the surface of the paper material and a polypropylene film was used as the formed film.

[0095] Comparative Example 3 The material of the paper container 20 is paper (uncoated paper) (manufactured by Oji F-Tex Co., Ltd., cup base paper, basis weight 220 g / m 2Adhesion evaluation and peelability evaluation tests were performed in the same manner as in Example 1, except that a heat sealant was used, no heat sealant was applied to the surface of the paper material, and a film (skin pack film manufactured by Sumitomo Bakelite Co., Ltd.) was used as the molded film.

[0096] The above results are shown in Table 1.

[0097] [Table 1]

[0098] In the adhesion evaluation column of Table 1, "◯" means that the formed film 40 was firmly adhered to the paper container 20. "△" means that only a part of the formed film was adhered to the paper container. "X" means that the formed film was not adhered to the paper container.

[0099] Furthermore, in the column for the peelability evaluation test in Table 1 above, "○" means that when the molded film 40 was peeled off from the paper container 20, no paper peeling (peeling off of part of the paper container) occurred on the paper container 20, and the molded film 40 could be easily peeled off from the paper container 20.

[0100] As a result, as shown in Table 1, in the peelability evaluation, the molded film was not adhered to the paper container in the paper containers of Comparative Example 1 and Comparative Example 2. In the paper container of Comparative Example 3, only a part of the molded film was adhered to the paper container.

[0101] In contrast, in the paper containers 10 according to Examples 1 to 9, the molded film 40 was firmly attached to the paper container 20. Therefore, in the paper container 10 according to the present embodiment, by applying a heat seal agent to the surface of the paper container 20, it was found that restrictions on the resin used in the molded film 40 can be suppressed, and the freedom of manufacturing conditions can be improved.

[0102] Furthermore, as shown in Table 1, in the paper containers 10 according to Examples 1 to 9, even when a heat sealant was applied to the surface of the paper container 20, when the molded film 40 was peeled off from the paper container 20, no paper peeling occurred on the paper container 20, and the molded film 40 could be easily peeled off from the paper container 20. Therefore, in the paper container 10 according to this embodiment, even when a heat sealant was applied to the surface of the paper container 20, the paper container 20 and the molded film 40 can be easily separated when recycling the paper container 20, and it was found that recyclability can be improved.

[0103] The present disclosure is not limited to the above-mentioned embodiment and each modification, and the components can be modified and embodied in the implementation stage without departing from the gist of the present disclosure. In addition, various inventions can be formed by appropriate combinations of the multiple components disclosed in the above-mentioned embodiment and each modification. Some components may be deleted from all the components shown in the embodiment and each modification. [Explanation of symbols]

[0104] 10 Paper containers 20 Paper containers 21 Bottom 22 Line 23 Side 24 Line 25 Flange piece 30 Blank material 31 Bottom Panel 32 First broken line 33 Side Panel 34 Second broken line 35 Flange Single Panel 40 Forming film H Heat seal layer

Claims

[Claim 1] A paper container having a bottom, a plurality of side portions connected to the bottom via a first fold line, and a plurality of flange pieces connected to each of the side portions via a second fold line; A formed film laminated on a surface of the paper container, The side portions are adjacent to each other and are not continuous with each other, A paper container having a heat seal layer provided on at least a portion of the surface of the paper container.

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