Paper containers, paper containers with lids and blanks

Abstract

To provide a paper-based container, a paper-based container with a lid material and blank allowing for improving recyclability.SOLUTION: A paper-based container 10 comprises: a paper container 20 that has a bottom portion 21, a plurality of side portions 23 coupled to the bottom portion 21 through first bend lines 22 and a plurality of flange pieces 25 coupled to the side portions 23 through second bend lines 24; and a forming film 40 laminated over a surface of the paper container 20. The side portions 23 are adjacent one to another without continuing mutually. A heat-resistant seal layer AH is provided on at least a 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 storing food and drink to be taken home (so-called take-out products) or food and drink to be delivered to home 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] Incidentally, in such paper containers, recycling of the paper used in the paper containers is being promoted for the purpose of reducing the environmental load. However, in such paper containers, it may 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 part of the paper container. In this case, it may be difficult to peel the molded film from the paper container. For this reason, there is a demand for a container that allows consumers to easily peel the molded film from the paper container after use and allows the paper to be easily recycled.

[0006] 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 can improve recyclability. [Means for solving the problem]

[0007] 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 an anti-heat seal layer is provided on at least a portion of the surface of the paper container.

[0008] In one embodiment of a paper container, in the area where the anti-heat seal layer is provided, the adhesive strength between the paper container and the formed film is 0.05 N / 15 mm or more and 0.4 N / 15 mm or less, and in the area where the anti-heat seal layer is not provided, the adhesive strength between the paper container and the formed film may be greater than 0.4 N / 15 mm.

[0009] In one embodiment of a paper container, the anti-heat seal layer is provided on the bottom and on the sides, and the weight per unit area of ​​the anti-heat seal layer provided on the sides may be smaller than the weight per unit area of ​​the anti-heat seal layer provided on the bottom.

[0010] 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.

[0011] 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, wherein gaps are formed between the side panels, and a heat-seal resistant layer is provided on at least a portion of the surface of the blank material.

[0012] In one embodiment of the blank material, the heat-seal resistant layer is provided on the bottom panel and on the side panels, and the weight per unit area of ​​the heat-seal resistant layer provided on the side panels may be smaller than the weight per unit area of ​​the heat-seal resistant layer provided on the bottom panel. Effect of the Invention

[0013] According to the present disclosure, the recyclability of paper containers and paper containers with lids can be improved. [Brief description of the drawings]

[0014] [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 paper container according to a first modified example of the present embodiment. [Figure 9] FIG. 9 is a development view showing a blank for producing a paper container according to a first modified example of the present embodiment. [Figure 10] FIG. 10 is a perspective view showing a blank according to a second modified example of the present embodiment. [Figure 11] FIG. 11 is a development view showing another example of the blank piece according to the second modified example of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 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 selected and used appropriately. 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.

[0016] 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.

[0017] 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.

[0018] (Paper container) The paper container 20 has a bottom 21, a plurality of side portions 23 connected to the bottom 21 via a first fold line 22, and a plurality of flange pieces 25 connected to each of the side portions 23 via a second fold line 24.

[0019] 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.

[0020] The first fold line 22 connecting the bottom 21 and the side 23 may be formed in a perforated shape or a half-cut line. This makes it easier to fold the side 23 relative to the bottom 21. When the first fold line 22 is formed in a perforated shape, the molded film 40 is pressed against the paper container 20 in the vicinity of the first fold line 22 by sucking air through a suction hole 61 of a cavity side die 60 described below. This improves the adhesion between the molded film 40 and the paper container 20.

[0021] 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.

[0022] 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.

[0023] The second fold line 24 connecting the side portion 23 and the flange piece 25 may be formed in a perforated shape or a half-cut line, similar to the first fold line 22. This makes it easier to fold the flange piece 25 relative to the side portion 23. When the second 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 second fold line 24 by sucking air through a suction hole 61 of a cavity side die 60 described below. This improves the adhesion between the formed film 40 and the paper container 20.

[0024] 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 into an overall ring shape.

[0025] 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.

[0026] Here, the heat-sealing resistant layer AH is provided on at least a part of the surface of the paper container 20 (the surface of the blank material 30 described later) other than the flange piece 25 (flange piece panel 35). This allows the adhesive strength between the paper container 20 and the formed film 40 to be easily adjusted. This allows the desired adhesive strength to be easily obtained. In this embodiment, the heat-sealing resistant layer AH is provided on the entire surface of the bottom 21 and the side 23 (the bottom panel 31 and the side panel 33 described later). This heat-sealing resistant layer AH is formed by applying an anti-heat-sealing agent to the bottom 21 and the side 23 (the bottom panel 31 and the side panel 33 described later). The heat-sealing resistant agent may be an ink using an acrylate resin as a raw material, an ink containing silicone or fluorine, or a wax or varnish. The heat-sealing resistant agent may also be applied to the bottom 21 and the side 23 (the bottom panel 31 and the side panel 33 described later) by gravure printing, flexographic printing, offset printing, or the like. In FIG. 2 and other figures, the region where the heat-sealing resistant layer AH is provided is shown shaded.

[0027] Also, the weight per unit area of ​​the heat-sealing resistant layer AH provided on the side 23 (side panel 33 described later) may be smaller than the weight per unit area of ​​the heat-sealing resistant layer AH provided on the bottom 21 (bottom panel 31 described later). That is, the amount of the heat-sealing resistant agent applied on the side 23 (side panel 33 described later) may be smaller than the amount of the heat-sealing resistant agent applied on the bottom 21 (bottom panel 31 described later). In this case, the adhesive strength between the paper container 20 and the formed film 40 in the paper container 10 can be easily adjusted. Therefore, the desired adhesive strength can be easily obtained.

[0028] 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 formed 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 formed film 40 and the adhesive strength between the bottom portion 21 and the formed film 40. However, if the adhesive strength between the side portion 23 and the formed film 40 and the adhesive strength between the bottom portion 21 and the formed film 40 are made too small, there is a possibility that the formed 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 formed film 40 is made too small, the formed film 40 will easily peel off from the paper container 20 starting from the portion of the formed 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.

[0029] In this embodiment, no anti-heat seal agent is applied onto the flange piece 25 (flange piece panel 35). In addition, the amount of anti-heat seal agent applied onto the side portion 23 is less than the amount of anti-heat seal agent applied onto the bottom portion 21. Therefore, the adhesive strength between the flange piece 25 and the formed film 40 can be made 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 made 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.

[0030] The weight per unit area of ​​the heat-sealing resistant layer AH (i.e., the amount of the heat-sealing resistant agent applied to the bottom portion 21 and the side portion 23 (the bottom panel 31 and the side panel 33 described later)) is 0.1 g / m 2 More than 10.0g / m 2 The amount of the heat-sealing agent applied to the bottom 21 and the side 23 (the bottom panel 31 and the side panel 33 described below) may be less than 0.1 g / m 2 As a result, the adhesive strength between the bottom 21 and side 23 and the molded film 40 can be easily reduced to a desired strength. Therefore, when recycling the paper container 20, the paper container 20 and the molded film 40 can be easily separated. In addition, when the amount of anti-heat seal agent applied to the bottom 21 and side 23 (bottom panel 31 and side panel 33 described later) is 10.0 g / m 2By satisfying the following conditions, deterioration in quality due to insufficient drying or curing of the anti-heat-sealing agent can be suppressed. If the adhesive strength between the side portion 23 and the formed film 40 and the adhesive strength between the bottom portion 21 and the formed film 40 are made too small, as described above, there is a possibility that the formed 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 contrast, since the adhesive strength between the bottom portion 21 and the side portion 23 and the formed film 40 can be prevented from becoming too small, deterioration in the openability of the lid material 50 can be suppressed.

[0031] Next, the adhesive strength between the paper container 20 and the formed film 40 will be described.

[0032] In the region where the heat-sealing-resistant layer AH is provided, the adhesive strength between the paper container 20 and the formed film 40 may be 0.05 N / 15 mm or more and 0.4 N / 15 mm or less. That is, the adhesive strength between the bottom 21 and the formed film 40 and the adhesive strength between the side 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 making these adhesive strengths 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 23 of the paper container 20 when removing the lid material 50 from the paper container 10 of the lid-attached paper container 1. In addition, by making these adhesive strengths 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. As described above, the adhesive strength between the bottom 21 and the molded film 40 and the adhesive strength between the side portion 23 and the molded 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 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 strip of 15 mm width 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.).

[0033] Furthermore, in the area where the heat-sealing resistant layer AH is not provided, the adhesive strength between the paper container 20 and the formed film 40 may be greater than 0.4 N / 15 mm. That is, the adhesive strength between the flange piece 25 and the formed film 40 may be greater than 0.4 N / 15 mm. This makes it possible to prevent the formed film 40 from peeling off from the flange piece 25 when removing the lid material 50 from the paper container 10. This makes it possible to prevent the ease of opening the lid material 50 from decreasing.

[0034] Also, the adhesive strength between the flange piece 25 and the molded film 40 may be 5.0 N / 15 mm or less. 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. In this case, when recycling the paper container 20, peeling (part of the paper container may peel off) may occur on the paper container 20 from which the molded film 40 has been peeled off.

[0035] (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 first fold line 22, the side 23, the second fold line 24, and the flange piece 25 of the paper container 20, respectively.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] (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).

[0040] 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.

[0041] 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)

[0042] Each of the above layers is formed according to a conventional method, such as dry lamination, extrusion lamination, extrusion coating, or other coating method.

[0043] 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.

[0044] 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.

[0045] 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)

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Manufacturing method of paper container First, the blank material 30 is prepared. In this process, a paper material is prepared and a heat-sealing agent is applied to a predetermined position of the paper material. The heat-sealing agent may be applied by gravure printing, flexographic printing, offset printing, or the like. In this way, a heat-sealing layer AH is provided at a predetermined position of the paper material. Next, the blank material 30 is obtained by punching the paper material with a Thomson blade or the like.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] As described above, according to this embodiment, the heat-seal resistant layer AH is provided on at least a part of the surface of the paper container 20. This allows the adhesive strength between the paper container 20 and the forming film 40 to be easily adjusted. In addition, the adhesive strength between the paper container 20 and the forming film 40 can be partially changed, or the forming film 40 can be attached to only a part of the paper container 20. Furthermore, since the adhesive strength between the paper container 20 and the forming film 40 can be adjusted, there are no restrictions on the resin used for the forming film 40. This allows for improved freedom in manufacturing conditions. In addition, since the adhesive strength between the paper container 20 and the forming film 40 can be easily adjusted, the desired adhesive strength can be easily obtained.

[0058] 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.

[0059] Furthermore, according to this embodiment, the weight per unit area of ​​the heat-seal resistant layer AH provided on the side portion 23 is smaller than the weight per unit area of ​​the heat-seal resistant layer AH provided on the bottom portion 21. Also, no heat-seal resistant agent is applied to the flange piece 25 (flange piece panel 35). Therefore, the adhesive strength between the flange piece 25 and the formed film 40 can be made 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 made 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. Also, 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.

[0060] Variations Next, modified examples of the paper container 10 and blank 30 according to the present embodiment will be described with reference to Figures 8 to 11. In Figures 8 to 11, the same parts as those in the embodiment shown in Figures 1 to 7 are designated by the same reference numerals and detailed description will be omitted.

[0061] (First Modification) In the above-mentioned embodiment, an example in which the heat-sealing resistant layer AH is provided on the entire surface of the bottom 21 and the side 23 (the bottom panel 31 and the side panel 33) has been described, but the present invention is not limited to this. For example, as shown in FIG. 8, the heat-sealing resistant layer AH may be provided only on the bottom 21. In this case, as shown in FIG. 9, in the blank 30, the heat-sealing resistant layer AH may be provided only on the bottom panel 31. Even in this case, the forming film 40 can be prevented from peeling off from the paper container 20 when the lid material 50 is removed from the paper container 10, and the paper container 20 and the forming film 40 can be easily separated when the paper container 20 is recycled. Therefore, the ease of opening the lid material 50 can be prevented from decreasing, and the paper container 20 and the forming film 40 can be easily separated when the paper container 20 is recycled.

[0062] (Second Modification) Also, as shown in FIG. 10 and FIG. 11, the heat-sealing-resistant layer AH may be provided in a predetermined pattern on the entire surface of the blank material 30. For example, as shown in FIG. 10, the heat-sealing-resistant layer AH may be provided on the surface of the blank material 30 so as to present a polka dot pattern. Also, as shown in FIG. 11, the heat-sealing-resistant layer AH may be provided in a striped pattern on the surface of the blank material 30. The pattern shape of the heat-sealing-resistant layer AH is not particularly limited. Although not shown, the heat-sealing-resistant layer AH may be provided on the surface of the blank material 30 so that the area where the heat-sealing-resistant layer AH is not provided presents a polka dot pattern. Also, the heat-sealing-resistant layer AH may be provided on the surface of the blank material 30 so as to present another pattern such as a checkered pattern, or may be provided on the surface of the blank material 30 in a lattice pattern. Also, although not shown, in this case, the heat-sealing-resistant layer AH is provided on the entire surface of the paper container 20 produced from the blank material 30 in a predetermined pattern. The heat-seal resistant layer AH may be provided on a portion of the surface of the blank material 30 in a predetermined pattern.

[0063] (Third Modification) Although not shown, a heat seal resistant layer AH may be provided on at least a portion of the surface of the flange piece 25 of the paper container 20. In this case, the heat seal resistant layer AH may be provided on at least a portion of the surface of the flange piece panel 35 in the blank material 30. Even in this case, the formed film 40 can be prevented from peeling off from the paper container 20 when the lid material 50 is removed from the paper container 10, and the paper container 20 and the formed film 40 can be easily separated when the paper container 20 is recycled. This prevents the ease of opening the lid material 50 from decreasing, and the paper container 20 and the formed film 40 can be easily separated when the paper container 20 is recycled. EXAMPLES

[0064] Next, a specific example of the above embodiment will be described.

[0065] 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, an anti-heat seal agent containing an acrylate resin (UV L Carton (product name) manufactured by T&K TOKA) was applied by offset printing to the entire surface of the paper material in the areas corresponding to the bottom panel 31 and the side panels 33. In addition, a film containing an ethylene-vinyl acetate copolymer was prepared as the forming film 40. Next, the film was laminated on the surface of the paper material to produce the paper container 10.

[0066] (1) Adhesive strength measurement test Next, an adhesive strength evaluation test was performed between the paper container 20 and the molded film 40. The test pieces were the bottom 21 to which the molded film 40 was attached, cut into a rectangle having a width of 15 mm and a length of 50 mm. A total of three test pieces were prepared. Next, a 90° peel test was performed on these test pieces using a tensile tester (for example, Tensilon universal material testing machine: RTC1310A, manufactured by Orientec Co., Ltd.) at a peel speed of 50 mm / min to measure the adhesive strength between the bottom 21 and the molded film 40. The average value of all the test pieces was taken as the adhesive strength between the bottom 21 and the molded film 40.

[0067] Also, an adhesive strength evaluation test was conducted between the side portions 23 and the molded film 40. The side portions 23 to which the molded film 40 was adhered were cut into a rectangular shape having a width of 15 mm and a length of 50 mm to be used as test pieces. At this time, a total of 12 test pieces were prepared, three for each side portion 23. Next, the adhesive strength between the side portions 23 and the molded film 40 was measured in the same manner as in the measurement of the adhesive strength between the bottom portion 21 and the molded film 40. The average value of all the test pieces was taken as the adhesive strength between the side portions 23 and the molded film 40.

[0068] Furthermore, an adhesive strength evaluation test was conducted between the flange pieces 25 and the molded film 40. The flange pieces 25 to which the molded film 40 was adhered were cut into rectangular shapes with a width of 15 mm and a length of 50 mm to be used as test pieces. In this case, a total of 12 test pieces were prepared, three for each flange piece 25. Next, the adhesive strength between the flange pieces 25 and the molded film 40 was measured in the same manner as in the measurement of the adhesive strength between the bottom 21 and the molded film 40. The average value of all the test pieces was taken as the adhesive strength between the flange pieces 25 and the molded film 40.

[0069] (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.

[0070] Example 2 An adhesive strength measurement test and a peelability evaluation test were carried out in the same manner as in Example 1, except that a wax-containing heat-sealing agent (UV low odor peelable OP varnish, manufactured by DIC Graphics) was used.

[0071] Example 3 An adhesive strength measurement test and a peelability evaluation test were carried out in the same manner as in Example 1, except that a silicone-containing heat-sealing agent (UV Carton US release varnish, manufactured by DIC Graphics) was used.

[0072] Example 4 An adhesive strength measurement test and a peelability evaluation test were carried out in the same manner as in Example 1, except that an anti-heat seal agent containing an oil-resistant resin (Solvella PT5060 (product name) manufactured by Solvay Socresis) was used.

[0073] Comparative Example 1 The adhesive strength measurement test and peelability evaluation test were carried out in the same manner as in Example 1, except that no anti-heat-sealing agent was applied to the surface of the paper material.

[0074] The above results are shown in Table 1.

[0075] [Table 1]

[0076] In the column for peelability in Table 1 above, "◯" means that when the molded film 40 was peeled off from the paper container 20, no paper peeling (part of the paper container peeled off) occurred on the paper container 20, and the molded film 40 could be easily peeled off from the paper container 20. Also, "×" means that when the molded film was peeled off from the paper container, some paper peeling occurred on the paper container.

[0077] As a result, as shown in Table 1, in the peelability evaluation test, in the paper container of Comparative Example 1, when the formed film was peeled off from the paper container, paper peeling occurred on the paper container.

[0078] In contrast, in the paper containers 10 according to Examples 1 to 4, when the molded film 40 was peeled off from the paper container 20, no peeling occurred on the paper container 20, and the molded film 40 could be easily peeled off from the paper container 20. Therefore, it was found that with the paper container 10 according to this embodiment, the paper container 20 and the molded film 40 can be easily separated when recycling the paper container 20, improving recyclability.

[0079] 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]

[0080] 10 Paper containers 20 Paper containers 21 Bottom 22 First broken line 23 Side 24 Second broken 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 50 Lid material AH Heat seal resistant layer

Claims

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 heat-seal resistant layer is provided on at least a portion of the surface of the paper container, The heat-seal resistant layer is provided on the bottom and on the sides, the weight per unit area of ​​the heat-seal resistant layer on the side is less than the weight per unit area of ​​the heat-seal resistant layer on the bottom; an adhesive strength between the flange piece and the formed film is greater than an adhesive strength between the side portion and the formed film; A paper container, wherein the adhesive strength between the side portion and the formed film is greater than the adhesive strength between the bottom portion and the formed film.

2. In the region where the heat-sealing resistant layer is provided, the adhesive strength between the paper container and the formed film is 0.05 N / 15 mm or more and 0.4 N / 15 mm or less; 2. The paper container according to claim 1, wherein the adhesive strength between the paper container and the forming film in the area where the heat-sealing resistant layer is not provided is greater than 0.4 N / 15 mm.

3. The paper container according to claim 1 or 2, A paper container with a lid, comprising a lid that seals the paper container.

4. A blank material having a molded film laminated on its surface, 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, A gap is formed between the side panels, A heat-seal resistant layer is provided on at least a portion of the surface, the heat seal resistant layer is disposed on the bottom panel and on the side panels; A blank material, wherein the weight per unit area of ​​the heat seal resistant layer on the side panels is less than the weight per unit area of ​​the heat seal resistant layer on the bottom panel.

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