Lid material and packaging container

Abstract

To provide a lid material and a packaging container with a high paperization rate and excellent functionality.SOLUTION: A lid material attached to a mouth portion of a container body is formed by squeezing a circular sheet including a paper layer and thermoplastic resin layers laminated on one side and the other side of the paper layer. It comprises a paper molded body having a top surface portion and a skirt portion extending vertically from an edge of the top surface portion, and a resin molded body made of a resin material containing thermoplastic resin and insert-molded inside the paper molded body. The resin molded body comprises a side surface portion provided to cover the entire inner circumferential surface of the skirt portion, and a rib provided to partially cover an inner surface of the top surface portion, extending radially from the center of the top surface portion and connected to the side surface portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lid material in which a molded resin body is inserted into a molded paper body, and a packaging container using the same. [Background technology]

[0002] In recent years, from the viewpoint of reducing the environmental load and protecting resources, there has been a demand for reducing the amount of resin used in packaging containers, etc. Therefore, efforts have been made to increase the paper content of the container bodies and lids of packaging containers, and for example, Patent Document 1 describes a paper container lid that is formed by drawing a blank sheet made of a single piece of paper base material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent application No. 2005-226337 Summary of the Invention [Problem to be solved by the invention]

[0004] The paper lid for containers described in Patent Document 1 is mostly made of paper, which is preferable from the viewpoint of reducing the amount of resin. However, because it is made of paper, it is not possible to provide the paper lid with screws or inner rings for fitting with the container body, and it is inferior in functionality to general packaging containers that are mainly made of resin, and there is room for improvement.

[0005] The present invention has been made in view of the above problems, and aims to provide a lid material and a packaging container that have a high paper content and excellent functionality. [Means for solving the problem]

[0006] One aspect of the present invention for solving the above problem is a lid material to be attached to the mouth of a container body, the lid material being formed by squeezing a circular sheet including a paper layer and a thermoplastic resin layer laminated on one side and the other side of the paper layer, and comprising a paper molded body having a top surface and a skirt portion extending perpendicularly from the edge of the top surface, and a resin molded body made of a resin material containing thermoplastic resin and insert molded inside the paper molded body, the resin molded body comprising a side portion arranged to cover the entire inner surface of the skirt portion, and a rib arranged to partially cover the inner surface of the top surface, extending radially from the center of the top surface, and connected to the side portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a lid material and a packaging container that have a high paper recycling rate and excellent functionality. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a packaging container according to an embodiment. [Figure 2] 1 is a bottom view of a lid member according to an embodiment; [Figure 3] 1 is a cross-sectional view of an example of a sheet constituting a paper sheet; [Figure 4] 1 is a bottom view of a lid member according to an embodiment; [Figure 5] Schematic perspective view of a lid according to a reference example. DETAILED DESCRIPTION OF THE INVENTION

[0009] FIG. 1 is a cross-sectional view showing a schematic configuration of a packaging container according to an embodiment, and more specifically, FIG. 1(a) is a cross-sectional view showing a schematic configuration of the packaging container according to an embodiment, and FIG. 1(b) is a partially enlarged view of FIG. 1(a). FIG. 2 is a bottom view of a lid according to an embodiment. The cross section of the packaging container shown in FIG. 1 corresponds to a cross section taken along line I-I' of the lid in FIG. 2. For convenience, the male screw 6a is omitted from FIG. 2. The packaging container 100 comprises a lid 1 and a container body 2, and contains contents such as foodstuffs and cosmetics.

[0010] (lid material) The lid material 1 is attached to the mouth 5 of the container body 2 and closes the packaging container 100. The lid material 1 is composed of a molded paper body 20 made mainly of paper, and a molded resin body 30 made mainly of resin and inserted inside the molded paper body 20. The welding strength between the molded paper body 20 and the molded resin body 30 is preferably 5 N / 15 mm or more. If the welding strength is less than 5 N / 15 mm, the molded paper body 20 and the molded resin body 30 may separate during use.

[0011] (Paper molding) The molded paper body 20 has a top surface 21 and a skirt portion 22 extending perpendicularly from the edge of the top surface 21, and is obtained by drawing a circular sheet 10 made mainly of paper. The skirt portion 22 of the molded paper body 20 preferably has a folded portion 23 formed by folding the edge of the sheet 10 inward. By providing the folded portion 23, the physical strength of the lid material 1 can be improved without increasing the amount of resin.

[0012] 3 is a cross-sectional view of an example of a sheet constituting the paper sheet 10. The sheet 10 is composed of a laminate including, for example, a protective layer 15, an ink layer 12, a thermoplastic resin layer 11, a paper layer 13, a functional layer 14, a thermoplastic resin layer 11, an ink layer 12, and a protective layer 15, in that order from the outermost layer.

[0013] The protective layer 15 is an outermost and innermost layer provided to protect the ink layer 12, and is made of a thermoplastic resin or overprint varnish (OP varnish). When a thermoplastic resin is used for the protective layer 15, it is preferably weldable to the resin molded body 30. In this case, the thermoplastic resin is preferably the same material as the resin molded body 30 in consideration of weldability, but it may be different from the resin molded body 30 as long as a weld strength of 5 N / 15 mm or more can be ensured. When forming the protective layer 15 from a thermoplastic resin, methods such as film lamination, extrusion processing, and coating can be used. Furthermore, when an OP varnish is used for the protective layer 15, or when a thermoplastic resin is used for the protective layer 15 but the weld strength between the protective layer 15 and the resin molded body 30 is not 5 N / 15 mm or more, the protective layer 15 is not formed where the resin molded body 30 will be located, and the resin molded body 30 is welded to the thermoplastic resin layer 11 located inside the protective layer 15. If the resin molded body 30 is welded to the paper molded body 20, the protective layer 15 may be omitted.

[0014] The ink layer 12 is a layer that is printed to display various types of information, and is provided inside the protective layer 15. Ordinary inks can be used for printing. In addition, although the ink layer 12 is arranged outside the thermoplastic resin layer 11 in FIG. 3, it may be arranged inside the thermoplastic resin layer 11 so that the layering order of the ink layer 12 and the thermoplastic resin layer 11 is reversed. The ink layer 12 may also be omitted.

[0015] The thermoplastic resin layer 11 is provided to improve the weldability between the molded paper product 20 and the molded resin product 30, and is an essential layer when the weld strength between the protective layer 15 and the molded resin product 30 is less than 5 N / 15 mm. The thermoplastic resin layer 11 is welded to the molded resin product 30 through a portion where the protective layer 15 is not formed. In consideration of weldability, the thermoplastic resin layer 11 is preferably made of the same material as the molded resin product 30, but may be made of a different material from the molded resin product 30 as long as a weld strength of 5 N / 15 mm or more can be ensured. The thermoplastic resin layer 11 can be made of, for example, low-density polyethylene (LLDPE), polyethylene (PE), polypropylene (PP), cycloparaphenylene (CPP), polylactic acid (PLA), polybutylene succinate (PBS), polystyrene (PS), polyethylene terephthalate (PET), ethylene-vinyl alcohol copolymer (EVOH), cycloolefin polymer (COP), or the like. The thermoplastic resin layer 11 can be formed by dry lamination, extrusion processing, coating, etc. If the protective layer 15 can ensure a welding strength of 5 N / 15 mm or more to the resin molded body 30, the thermoplastic resin layer 11 may be omitted.

[0016] The paper layer 13 is a structural layer that imparts rigidity to the molded paper body 20 while reducing the amount of resin used in the lid material 1. There are no particular restrictions on the type of paper used for the paper layer 13, but considering printability, it is preferable to use paper with a double gloss finish or a clay layer. As the paper, waterproof paper or oilproof paper may be used as needed. The basis weight of the paper used for the paper layer 13 is 190 to 600 g / m 2 The basis weight of the paper used for the paper layer 13 is preferably 190 g / m 2 If the paper weight is less than 600 g / m, the rigidity will be insufficient, causing insert failure of the resin molding 30, or the paper thickness will vary partially, causing burrs. 2 If it exceeds this value, the rigidity will be too high and it will be difficult to draw the sheet 10 into a lid shape. From the viewpoint of increasing the paper content of the lid material 1, the mass ratio of the paper layer 13 contained in the sheet 10 is preferably 50% or more.

[0017] The functional layer 14 is a functional layer that blocks oxygen, water vapor, etc., thereby improving the shelf life of the contents, and is provided, for example, on the inner side of the paper layer 13. The functional layer 14 can be made of, for example, aluminum foil, an inorganic vapor deposition film, or an organic barrier resin. Examples of inorganic vapor deposition films that can be used include aluminum, alumina, and silica. Examples of organic barrier resins that can be used include ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVA), and barrier nylon (MXD-NY). The functional layer 14 may be omitted.

[0018] (Resin molded body) The resin molded body 30 is inserted inside the molded paper body 20 and is a part used to form screws and inner rings for fitting the lid material 1 and the container body 2 together. Furthermore, the formation of the resin molded body 30 increases the physical strength of the lid material 1, preventing deformation of the lid material 1, for example, when the packaging container is opened, closed, or capped. The resin molded body 30 is made of a resin material containing a thermoplastic resin and is welded to the protective layer 15 or the thermoplastic resin layer 11 of the molded paper body 20, with a weld strength of preferably 5 N / 15 mm or more. The resin molded body 30 includes a rib 31 provided so as to partially cover the inner surface of the top surface 21, and a side surface 32 provided so as to entirely cover the inner circumferential surface of the skirt portion 22 of the molded paper body 20.

[0019] The rib 31 is provided on the inner surface of the top surface portion 21, extends radially from the center of the top surface portion 21, and is connected to the side surface portion 32. From the viewpoint of reducing the amount of resin, the rib 31 is preferably thin. Furthermore, the gate position for injection molding the resin molded body 30 is located at the center of the top surface portion 21. In this case, if there is only one rib 31 (i.e., one resin path within the mold), the resin may not circulate completely within the mold, which may cause shortcuts or weld cracks at the resin junction. Furthermore, if there are too many ribs 31, the amount of resin used increases, which is not preferable. Therefore, as shown in Figures 1 and 3, the number of ribs 31 is preferably two to four (i.e., two to four resin paths within the mold), and they are preferably arranged at equal angles to each other.

[0020] The side surface portion 32 is provided to cover the entire inner peripheral surface of the skirt portion 22 of the molded paper body 20, and the inner peripheral surface of the side surface portion 32 is provided with a male thread 6a that screws into a female thread 6b provided on the outer peripheral surface of the container body 2. This allows the lid material 1 and the container body 2 to be fitted together by screwing. The side surface portion 32 is also provided to cover the end surface of the folded portion 23 of the molded paper body 20, thereby protecting the end surface of the molded paper body 20. Furthermore, since the side surface portion 32 shrinks after injection molding, providing the side surface portion 32 can reduce the angle between the top surface portion 21 and the skirt portion 22 of the molded paper body 20, thereby suppressing the expansion of the skirt portion 22 and improving sealing performance. Note that as long as the lid material 1 can be attached to the container body 2 by a method other than screwing, for example, a convex portion may be formed on the side surface portion 32 of the molded resin body 30 so that it fits into the container body 2 via an undercut.

[0021] The resin molded body 30 may be provided with a cylindrical inner ring 34 that fits onto the inner circumferential surface of the mouth portion 5 of the container body 2 in order to improve the sealing performance of the packaging container 100. In this case, the annular portion 33 may be provided in a region of the inner circumferential surface of the top surface portion 21 that covers a ring-shaped region along the outer circumferential edge, and the inner ring 34 may be formed on the inner circumferential end of the annular portion 33. In this case, the annular portion 33 is connected to the rib 31 and the side surface portion 32. Note that the inner ring 34 and the annular portion 33 may be omitted.

[0022] (Container body) The container body 2 is not particularly limited as long as it has a mechanism that allows it to fit with the lid material 1, and can be made of general resin or paper. However, from the viewpoint of reducing the amount of resin, it is preferable that the container body 2 is made mainly of paper.

[0023] (Reference example) The effects of this embodiment will be described with reference to a reference example. FIG. 5 is a schematic perspective view of a lid material according to the reference example. The lid material 101 according to the reference example is configured by replacing a portion of a resin lid material with a paper insert material 120 primarily composed of paper. The paper insert material 120 is sandwiched and held by a resin molded body 130 near the outer periphery of the top surface. Therefore, like the present invention, the lid material 101 according to the reference example can also form screws and inner rings inside the resin molded body 130 while reducing the amount of resin. However, since the portions other than the top surface 21 are primarily composed of paper, the amount of resin used is greater than that of the present invention. On the other hand, since the portions other than the top surface 21 are primarily composed of paper, the amount of resin used can be reduced compared to the lid material 101 according to the reference example, and the paper content ratio of the lid material 1 (the mass percentage of paper contained in the lid material 1) can be increased to 50% or more. A paper content ratio of 50% can be obtained as a paper mark indicating that the lid material 1 is made of paper. In addition, in the lid material 101 according to the reference example, the outer surface of the top surface and the skirt portion are made of resin, so printing can only be applied to a portion of the top surface where no resin is present. On the other hand, in the present invention, the outer surface of the lid material 1 can be made of a sheet 10 mainly made of paper, so printing can be applied to the entire outer surface of the lid material 1.

[0024] As explained above, the lid material 1 according to this embodiment comprises the molded paper body 20 and the molded resin body 30 insert-molded inside the molded paper body 20. Therefore, a thread or the like for screwing with the container body 2 can be formed on the side surface portion 32 of the molded resin body 30, and the lid material 1 and the container body 2 can be fitted together in the same way as with lid materials and container bodies made of general resins.

[0025] The resin molded body 30 also includes an inner ring 34. This allows the sealing performance of the packaging container 100 to be improved.

[0026] Furthermore, the skirt portion 22 of the molded paper body 20 is provided with a folded portion 23 formed by folding the end face of the sheet 10 inward, thereby improving the physical strength of the lid material 1 without increasing the amount of resin.

[0027] Furthermore, the side surface portions 32 of the resin molded body 30 are provided so as to cover the end surfaces of the molded paper body 20. This makes it possible to protect the end surfaces of the molded paper body 20.

[0028] The resin molded body 30 has two to four ribs 31, which are arranged at equal angles to one another. This reduces the amount of resin used while also reducing the occurrence of short cuts and weld cracks at resin junctions during injection molding of the resin molded body 30.

[0029] Furthermore, the welding strength between the molded paper body 20 and the molded resin body 30 is 5N / 15mm or more, which makes it possible to prevent the molded paper body 20 and the molded resin body 30 from separating.

[0030] Furthermore, the mass ratio of the paper layer 13 contained in the sheet 10 is 50% or more. This makes it possible to make the paper content of the lid material 1 (mass ratio of the amount of paper contained in the lid material 1) 50% or more. [Example]

[0031] Example 1 A sheet 10 having the configuration shown in Table 1 was produced. Specifically, a 12 μm thick transparent barrier film (manufactured by TOPPAN Corporation, product name: GL-PET) and a 40 μm thick unstretched polypropylene film (CPP, manufactured by Futamura Chemical Co., Ltd., product name: FHK-2) were dry laminated together using a two-component curing urethane adhesive (manufactured by Toyo Ink Co., Ltd., product name: TM242A / B) to produce an interior film. 2 The interior film thus prepared was bonded to one side of a cardboard (manufactured by Oji Paper Co., Ltd., trade name: OK Frace PRO) via extrusion sand lamination with a 20 μm PE resin (manufactured by Mitsubishi Chemical Group Corporation, trade name: Novatec LD, trade name: LC600A), and an 18 μm PP resin (manufactured by Japan Polypropylene Corporation, trade name: Novatec PP (registered trademark) EA6A) was laminated to the other side by extrusion lamination to produce processed paper. The processed paper was cut, offset printed, and coated with OP varnish, and then punched to produce a circular sheet 10 with a diameter of 116 mm.

[0032] The produced sheet 10 was subjected to drawing to produce a molded paper body 20 having a folded portion 23 .

[0033] The produced molded paper body 20 was placed in an injection mold, and a molded resin body 30 was inserted by insert injection molding to produce the lid member 1. At this time, a screw and an inner ring were formed in the molded resin body 30.

[0034] Example 2 Cardboard basis weight: 190 g / m 2 A lid material 1 was produced in the same manner as in Example 1, except that:

[0035] Example 3 Cardboard basis weight: 600 g / m 2 A lid material 1 was produced in the same manner as in Example 1, except that:

[0036] Example 4 Lidding material 1 was produced in the same manner as in Example 1, except that a 12 μm thick transparent barrier film (manufactured by TOPPAN Corporation, product name: GL-PET) and a 40 μm thick LLDPE (manufactured by Tamapoly Corporation, product name: SE620A) were dry laminated together using a two-component curing urethane adhesive (manufactured by Toyo Ink Co., Ltd., product name: TM242A / B) to produce an interior film, and that an 18 μm thick PE resin (manufactured by Mitsubishi Chemical Group Corporation, product name: Novatec LD, product name: LC600A) was extrusion laminated on the other side of the card paper to produce processed paper.

[0037] Example 5 Basis weight 310g / m 2 Lid material 1 was produced in the same manner as in Example 1, except that PP resin was extrusion coated on both sides of double-sided coated paper (manufactured by Oji Paper Co., Ltd., product name: OK Frace PRO) to produce a treated paper.

[0038] Example 6 A lid material 1 was produced in the same manner as in Example 1, except that the sheet 10 was made into a circle having a diameter of 90 mm and the folded-back portion 23 was not formed.

[0039] (Comparative Example 1) A lid material was produced in the same manner as in Example 1, except that the resin molded body 30 was not produced.

[0040] (Comparative Example 2) A lid material was produced in the same manner as in Example 1, except that the sheet 10 was formed into a circle with a diameter of 57 mm, and the sheet 10 was not subjected to drawing, resulting in a lid material 101 according to the reference example shown in Fig. 5. At this time, an inner ring and a screw were formed on the side portion of the lid material 101.

[0041] (Comparative Example 3) Cardboard basis weight: 180 g / m 2 A lid material was produced in the same manner as in Example 1, except that:

[0042] Comparative Example 4 Cardboard basis weight: 650 g / m 2 A lid material was produced in the same manner as in Example 1, except that:

[0043] (Evaluation method) The lid materials produced in the examples and comparative examples were evaluated for the possibility of forming a draw on the sheet 10, the possibility of adding screws, the paper yield, and the sealability. Regarding the possibility of forming a draw and the possibility of adding screws, if the formation was possible, it was evaluated as ○, and if it was not possible, it was evaluated as ×. Regarding the paper yield, if the paper yield was 50% or more, it was evaluated as ○, and if it was less than 50%, it was evaluated as ×. To evaluate the sealability, a leakage check liquid (0.1% aqueous surfactant solution) was placed on the inside of the lid material, and after leaving it inverted for one day, the presence or absence of liquid leakage was checked, and if there was no leakage, it was evaluated as ○, and if there was leakage, it was evaluated as ×. Furthermore, as an overall evaluation, if all of the above evaluation items were ○, it was evaluated as ○, and otherwise it was evaluated as ×.

[0044] Table 1 shows the sheet configuration for each example and comparative example, whether or not the paper molded body 20 is drawn, whether or not the resin molded body 30 is formed, and the results of each evaluation. The numerical values ​​listed in the sheet configuration column in Table 1 represent the layer thickness (μm) or the basis weight of the paper.

[0045] [Table 1]

[0046] In all of the lid materials 1 according to Examples 1 to 6, the molded paper body 20 was produced by squeezing a sheet 10 mainly made of paper. Therefore, the paper conversion rate was 50% or more. Furthermore, a molded resin body 30 was formed inside the molded paper body 20. Therefore, the male thread 6a and inner ring 34 could be formed on the side surface portion 32 of the molded resin body 30, and excellent sealing properties were demonstrated.

[0047] The lid material according to Comparative Example 1 was not formed with the resin molded body 30. Therefore, the male thread 6a and the inner ring 34 could not be formed in the lid material 1, and the sealing performance was poor.

[0048] The lid material of Comparative Example 2 was made of resin except for the top surface, so the amount of resin used was large and the paper conversion rate was less than 50%.

[0049] The lid material according to Comparative Example 3 has a paper basis weight of 180 g / m 2 As a result, the rigidity of the sheet 10 was insufficient, and buckling occurred in the injection mold for the resin molded body 30, making it impossible to form a screw. In addition, the resin molded body 30 was poorly formed, so it did not function as a lid material. Furthermore, the paper-recycling rate was less than 50%.

[0050] The lid material according to Comparative Example 4 has a paper basis weight of 650 g / m 2 Therefore, the rigidity of the sheet 10 was too high, making it difficult to perform drawing, and it was not possible to mold it into the molded paper product 20. [Industrial Applicability]

[0051] The lid material and packaging container according to the present invention can be used as a lid material and packaging container that require airtightness. [Explanation of symbols]

[0052] 1: Lid material 2: Container body 5: Mouth 6a: Male thread 6b: Female thread 10: Sheet 11:Thermoplastic resin layer 12: Ink layer 13:Paper layer 14: Functional layer 15:Protective layer 20: Paper molding 21:Top section 22: Skirt section 23: Folded section 30: Resin molded body 31: Rib 32: Side part 33: Annular section 34: Inner ring 100: Packaging container

Claims

1. A lid material attached to the mouth of a container body, a molded paper body formed by drawing a circular sheet including a paper layer and thermoplastic resin layers laminated on one side and the other side of the paper layer, the molded paper body having a top surface portion and a skirt portion extending perpendicularly from an edge of the top surface portion; a resin molded body made of a resin material containing a thermoplastic resin and insert-molded inside the paper molded body; The resin molded body is a side surface portion provided to cover the entire inner circumferential surface of the skirt portion; a rib that is provided to partially cover the inner surface of the top surface portion, extends radially from the center of the top surface portion, and is connected to the side surface portion.

2. The resin molded body is an annular portion provided to cover an annular region along an outer circumferential edge of an inner circumferential surface of the top surface portion and connected to the side surface portion and the rib; a cylindrical inner ring provided in the annular portion; The lid according to claim 1 , wherein the inner peripheral surface of the side portion is provided with a male thread that meshes with a female thread provided on the outer peripheral surface of the container body.

3. The skirt portion of the molded paper body is provided with a folded portion in which an end surface of the sheet is folded inward, The lid member according to claim 1 , wherein the side surface of the resin molded body is provided so as to cover the end surface of the paper molded body.

4. The lid material according to claim 1, wherein the number of the ribs is 2 to 4, and the ribs are arranged at equal angles to each other.

5. The lid material according to claim 1, wherein the weld strength between the molded paper body and the molded resin body is 5 N / 15 mm or more.

6. The lid material according to claim 1 , wherein the paper layer comprises 50% or more by mass of the sheet.

7. A packaging container comprising the lid material according to any one of claims 1 to 6 and the container body.

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