Double container, refill container, and method for manufacturing refill container

Abstract

A double container 3 has an outer container 2 and an inner container 1 housed in the outer container 2 in a replaceable manner as a refill. The outer container 2 has a bottom wall 21, a side wall 22, and a cylindrical mouth part 23 positioned above the side wall 22. The inner container 1 has a bottom surface 11, a side surface part 12, an upper end flange 15 protruding radially outward from the entire periphery of the upper end part of the side surface part, and hanging tabs 17 that hang downward from the outer edge of the upper end flange 15. Thin parts 27A, 27B are provided to the mouth part 23 of the outer container 2, and in the state of the double container 3 in which the inner container 1 is mounted onto the outer container 2, the upper end flange 15 of the inner container 1 is positioned on the upper end of the mouth part 23 of the outer container 2, and the hanging tabs 17 are positioned on the outside of the thin parts 27A, 27B, respectively. The inner container 1 is composed of a resin sheet material.

Description

Double container, refill container, and method for manufacturing refill container

[0001] The present invention relates to a double container, a refill container included in the double container, and a method for manufacturing the refill container.

[0002] In recent years, in the field of cosmetics, the use of double-layered containers with replaceable inner containers has become widespread in order to conserve resources from the perspective of the Sustainable Development Goals (SDGs). The resin inner containers used in such double-layered containers have often been manufactured by injection molding. To further reduce the amount of resin used, inner containers manufactured by sheet molding have also been proposed (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-97318

[0004] In the above-mentioned Patent Document 1, a flange is provided at the top end of the inner container, and the double container is assembled by fitting it into the outer container from above. However, when replacing the inner container as a refill, when the flange of the inner container is peeled off from the top end of the mouth of the outer container, there is no part on the inner container to grab to release the engagement, making it difficult to disassemble.

[0005] In view of the above circumstances, the present invention aims to provide a double container that reduces the amount of resin used and allows the inner container to be easily disengaged from the outer container when replacing it as a refill.

[0006] In order to solve the above problems, one aspect of the present invention provides a double container having an outer container and an inner container that is replaceably stored in the outer container as a refill, wherein the outer container has a bottom wall, a side wall, and a cylindrical mouth portion located on the side wall, the inner container has a bottom surface, a side portion, an upper flange that protrudes radially outward from the entire periphery of the upper end of the side portion, and a hanging tab that hangs down from the outer edge of the upper flange, the mouth portion of the outer container is provided with thin-walled portions in the same number as the hanging tabs, and when the inner container is attached to the outer container to form a double container, the upper flange of the inner container is located above the upper end of the mouth portion of the outer container and the hanging tabs are located outside the thin-walled portions, and the inner container is made of a resin sheet material.

[0007] According to one aspect, in the double container, when the inner container is replaced as a refill, it is easy to release the engagement from the outer container.

[0008] 1 is a perspective view of a double container according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of a double container according to the first embodiment. FIG. 3 is a cross-sectional view of a double container according to the first embodiment. FIG. 4 is an exploded perspective view of a double container with a cap according to the first embodiment. FIG. 5 is a bottom perspective view of an inner container according to the first embodiment. FIG. 6 is a flowchart of a first manufacturing method for the inner container of FIG. 4. FIG. 7 is a cross-sectional view of a first manufacturing method for an inner container. FIG. 8 is a cross-sectional view of a second manufacturing method for an inner container of FIG. 8. FIG. 9 is a cross-sectional view of a second manufacturing method for an inner container of FIG. 8. FIG. 10 is a cross-sectional view of a second manufacturing method for an inner container of FIG. 8. FIG. 11 is a cross-sectional view of a second manufacturing method for an inner container of FIG. 8. FIG. 12 is a cross-sectional view of a second manufacturing method for an inner container of FIG. 8. FIG. 13 is a cross-sectional view of a second manufacturing method for an inner container of FIG. 8. FIG. 14 is a cross-sectional view of a second manufacturing method for an inner container of FIG. 8. FIG. 15 is a cross-sectional view of a third manufacturing method for an inner container according to a third embodiment of the present invention.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes embodiments of the present invention with reference to the accompanying drawings. In the following drawings, the same components are designated by the same reference numerals, and redundant explanations may be omitted.

[0010] The present invention relates to a double-walled container, particularly a double-walled container for storing a viscous or solid substance. The inner container of the double-walled container is a sheet-formed resin container, which may or may not be self-supporting. The outer container of the double-walled container is a self-supporting container, preferably made of glass, but may also be made of wood, resin, silicone, metal, paper, etc.

[0011] It is preferable that the contents placed in the inner container held by the outer container of the double container of the present invention are not single-use items such as cosmetics, perfumes, detergents, seasonings, etc., but viscous or solid substances that are to be used in portions.

[0012] In this specification, viscous substances refer to viscous cosmetics such as viscous creams, hair waxes, ointments, viscous medicines, viscous soaps, etc. Solid substances refer to solid or semi-solid cosmetics such as particularly hard hair sticks, hair waxes, and solid beauty serums (for example, those with a similar hardness to stick beauty serums), as well as solid soaps, cheese, butter, and other foods.

[0013] In the present invention, the viscous or solid substance is filled in the storage section in advance, and the inner container is set in the outer container in advance, or the viscous or solid substance is filled by replacing the inner container as a refill (refill container).

[0014] <Overall configuration of first embodiment> First, the overall configuration of the double container according to the first embodiment of the present invention will be described using Figures 1 to 4. Figure 1 is a perspective view of the double container according to the first embodiment of the present invention. Figures 2A and 2B are cross-sectional views of the double container according to the first embodiment. In Figures 2A and 2B, Figure 2A is a cross-sectional view taken along line AA' in Figure 1, and Figure 2B is a cross-sectional view taken along line BB' in Figure 1. Figure 3 is an exploded perspective view of the double container with a cap according to the present invention. Figure 4 is a bottom perspective view of the inner container according to the first embodiment of the present invention.

[0015] The double container 3 according to the present invention comprises an inner container 1 and an outer container 2. The double container 3 shown in Figures 2A and 2B has a wide-mouthed, low-profile jar shape. The double container 3 can be engaged with a cap 4 (see Figure 4).

[0016] In this embodiment, the inner container 1 comprises a cylindrical storage section 10 with a bottom having a bottom surface 11 and a side surface 12, an upper flange 15 that protrudes outward from the upper end of the storage section 10, and a hanging tab (hanging piece) 17 that hangs down in a rectangular cross section from a part of the outer edge of the upper flange 15.

[0017] More specifically, a portion of the outer edge of the upper flange 15 is recessed inward, and the recessed outer edge is provided with a hanging tab 17 that hangs down from the outer edge of the recessed narrow flange 15R.

[0018] 2A, 2B, 3, and 4, outer edge 17E of the outer peripheral surface (outer surface) of hanging tab 17 is raised outward more than other portions, and a circumferentially extending convex portion (inner rib) 18 is provided on the inner peripheral surface (inner surface) of hanging tab 17. More specifically, as shown in Fig. 4, hanging tab 17 has a uniform thickness, and is stretched by vacuum molding to form convex portion 18 that protrudes inward, resulting in a concave outer surface.

[0019] The side surface portion 12 of the inner container 1 has a tapered side surface 13 at the bottom, the diameter of which decreases downward, and an upper polygonal cylindrical side surface 14. In this example, the cylindrical polygon constituting the upper polygonal cylindrical side surface 14 is a regular dodecagon, but the polygon is preferably a regular quadrilateral to a regular 24-gon. More preferably, it is a regular quadrilateral to a regular 15-gon. The provision of the tapered side surface 13, the diameter of which decreases at the bottom of the side surface of the inner container 1, makes it easier to remove a used inner container from the outer container and set an unused inner container (refill) into the outer container 2.

[0020] Fig. 2A is a cross-sectional view taken along a side of the polygonal cylindrical side surface 14 of the inner container 1, and Fig. 2B is a cross-sectional view taken along a corner of the polygonal cylindrical side surface 14. In the polygonal cylindrical side surface 14 at the top of the side surface portion 12 of the inner container according to this embodiment, the line connecting opposing sides in the polygonal cross section is shorter than the diagonal line connecting opposing corners.

[0021] Therefore, in the state of the double container 3, as shown in Fig. 2A, a gap (clearance) is formed between the sides (portions other than the corners) of the polygonal cylindrical side surface 14 of the inner container 1 and the inner surface of the mouth 23 of the outer container 2. For example, the gap is about 0.2 to 4 mm.

[0022] On the other hand, in the double container 3, the corners of the polygonal tube side surface 14 of the inner container 1 shown in Figure 2B are in contact with the inside surface of the mouth 23 of the outer container 2, i.e., there is zero clearance. As described above, since the inner container 1 is formed from a thin resin sheet, the polygonal tube side surface 14 is deformed by crushing the corners, even at the lower part of the inside surface of the mouth 23 of the outer container 2, where the diameter is smaller than at the upper end, and the polygonal tube side surface 14 and the mouth 23 are maintained in contact.

[0023] 2B shows an example in which the corners of the polygonal tube side surface 14 are in contact with the inner surface of the mouth 23 of the outer container 2 in the state of the double container 3, but in consideration of the possibility of manufacturing variations in the outer container 2, there may be a gap of about 0 to 2 mm between the corners of the polygonal tube side surface 14 and the inner surface of the mouth 23 of the outer container 2. Even when a gap occurs between the corners of the polygonal tube side surface 14 and the inner surface of the mouth 23 in this way, the gap distance is smaller than the gap between the edge of the polygonal tube side surface 14 and the inner surface of the mouth 23.

[0024] The inner container 1 is formed by sheet molding of a thin resin sheet. The resin constituting the inner container 1 may be, for example, a polyester resin such as polypropylene (PP), polyethylene (PE), acrylonitrile butadiene styrene (ABS), polybutylene terephthalate (PBT), polyacetal (POM), or polyethylene terephthalate (PET), polycarbonate (PC), an acrylic resin (PMMA), or a biodegradable resin.

[0025] The outer container 2 is a container housing portion that replaceably houses the inner container 1. The outer container 2 has a case portion 20 having a bottom wall 21 and a side wall 22. In the outer container 2, a shoulder portion 28 extending outward is provided at the upper end of the case portion 20, and a cylindrical mouth portion 23 extending upward is provided from the inner edge of the shoulder portion 28. As shown in Figures 1, 2A, and 2B, the cylindrical mouth portion 23 has a smaller diameter than the side wall 22 of the case portion 20 and is located more inward than the side wall 22.

[0026] As shown in Figure 3, the mouth 23 of the outer container 2 has thick-walled mouth portions 24A, 24B and thin-walled mouth portions 27A, 27B. The inner surface of the mouth 23 is a continuous circumferential surface, and the outer surface is formed of multiple alternating thick-walled mouth portions 24A, 24B and thin-walled mouth portions 27A, 27B, whose thickness changes stepwise from the circumferential surface. Specifically, the thin-walled mouth portions 27A, 27B are vertically elongated rectangular regions of the mouth 23 that are partially recessed on the outside, extending from the upper end of the mouth 23 but not reaching the lower end. Therefore, the portions of the mouth 23 below the annular ridges 26 of the thin-walled mouth portions 27A, 27B have the same thickness as the thick-walled mouth portions 24A, 24B.

[0027] In the mouth 23, the mouth thick portions 24A, 24B are circumferentially longer than the mouth thin portions 27A, 27B. Thread projections 25 are provided on the outer peripheral surfaces of the mouth thick portions 24A, 24B. Furthermore, an annular ridge 26 extending circumferentially is provided around the entire outer periphery of the lower portion of the mouth 23. In this embodiment, the thread projections 25 are interrupted circumferentially at or near the mouth thin portions 27A, 27B, while the lower annular ridge 26 is continuous circumferentially and provided below the mouth thin portions 27A, 27B. Furthermore, grooves 29 are provided on the outer peripheral surfaces of the mouth thin portions 27A, 27B.

[0028] The screw projections 25 of the outer container 2 threadably engage with the screw projections (not shown) of the cap 4. The annular ridges 26 are located below the screw projections 25, and the cap 4 engages by fitting over the annular ridges 26. The annular ridges 26 can also serve as a downward finger hook on the outer container 2 side when pulling the inner container 1 out of the outer container 2. Grooves 29 on the outer peripheral surfaces of the thin-walled mouth portions 27A, 27B are engaging portions into which the protrusions 18 on the inner surface of the hanging tab 17 of the inner container 1 fit.

[0029] The outer container 2 of the present invention is preferably made of glass, but may also be made of resin, wood, silicone, metal, paper, etc. In the case of resin, it may be made of, for example, polyester resins such as PP, PE, ABS, PBT, POM, PET, etc., or PC, PMMA, or biodegradable resins, as with the inner container 1 described above. In the case of wood, for example, coniferous wood such as cedar, cypress, and pine, and hardwood wood such as oak, walnut, black cherry, alder, and rubberwood, as well as bamboo, are included. In the case of paper, for example, it may be self-supporting cardboard.

[0030] 3, the cap 4 has a top surface 41 and a peripheral wall 42, and a threaded protrusion is provided on the inside of the peripheral wall 42. In Fig. 3, the upper surface of the top surface 41 is hemispherically convex upward, and the outer surface of the peripheral wall 42 widens downward. However, the shape of the cap is not limited to this, and the top surface of the top surface may be flat, and the outer surface of the peripheral wall may also have a shape with a constant diameter.

[0031] The cap 4 of the present invention is a lid that covers the upper flange 15 of the inner container 1 and the cylindrical opening 23 of the outer container 2, and is made of polyester resins such as PP, PE, ABS, PBT, POM, PET, etc., or resins such as PC, PMMA, or biodegradable resins, glass, wood, silicon, metal, paper, etc.

[0032] 3, a packing 5, which is a sealing material for preventing leakage, may be provided on the inside (lower side) of the top surface 41 of the cap 4. The packing 5 may be provided by adhering it to the cap 4, or may be provided separately from the cap 4. The packing 5 is formed of, for example, elastic rubber or resin (for example, PP or PE).

[0033] When the cap 4 is engaged with the double container 3, the screw projections 25 on the opening 23 of the outer container 2 are threadedly engaged with the screw projections on the cap 4. At this time, the gasket 5 is engaged in a state sandwiched between the underside of the top surface 41 of the cap 4 and the upper flange 15 of the inner container 1.

[0034] When the cap 4 and the double container 3 are engaged with each other with the elastic packing 5 sandwiched therebetween, the contents do not leak even if the double container 3 is tilted or turned upside down.

[0035] As shown in the exploded view of Figure 3, the inner container 1 is a replaceable (detachable and replaceable) refill together with the viscous or solid substance contained therein, while the outer container 2, cap 4, and packing 5 are reusable after replacement.

[0036] Therefore, the empty inner container 1 can be replaced with a new refill of the same shape, and the outer container 2 can be used repeatedly.

[0037] The inner container 1 that can be replaced as a replacement refill can have its top surface covered with a film stretched over the upper flange 15 or a cover that surrounds the upper flange 15. This allows the inner container 1 that is a refill to be distributed as a single unit.

[0038] 1 to 4 show an example in which the inner container 1 is provided with two hanging tabs 17, but the number of hanging tabs 17 may be one or three or more. Similarly, an example in which the mouth 23 of the outer container 2 is provided with two thin-walled mouth portions is shown, but the number of thin-walled mouth portions may be the same as the number of hanging tabs 17, or may be greater than the number of hanging tabs 17, and if there are more thin-walled mouth portions than hanging tabs, the number of thin-walled mouth portions is a multiple of the number of hanging tabs.

[0039] 3, in the double container 3 in which the inner container 1 and outer container 2 are engaged, the upper flange 15 of the inner container 1 is located above the upper end of the mouth 23 of the outer container 2. Therefore, the width of the upper flange 15 of the inner container is the same as or wider than the thickness of the thick-walled portions 24A, 24B of the mouth 23 of the outer container.

[0040] When engaging the inner container 1 configured as above with the outer container 2, the user pushes the upper flange 15 of the inner container 1 from above, pushing it into the outer container 2. This causes the hanging tab 17 of the inner container 1 to cover the outside of the thin-walled mouth portions 27A and 27B of the outer container 2, and the convex portions 18 on the inner surface of the hanging tab 17 to fit into the grooves 29 of the thin-walled mouth portions 27A and 27B.

[0041] Conversely, when replacing the refill, the user places their fingers on the thin-walled portions 27A, 27B of the outer container 2 and pushes up the lower end of the hanging tab 17 of the inner container 1, thereby disengaging the convex portion 18 on the inside surface of the hanging tab 17 from the groove portion 29 of the thin-walled opening portions 27A, 27B, and separating the inner container 1 from the outer container 2. Alternatively, the inner container 1 can be pulled upward relative to the outer container 2 by hooking a finger on the outer edge of the upper flange 15 of the inner container 1 or on a part of the inside surface of the side portion 12 of the inner container 1. Thus, in the double-walled container of the present invention, the inner container 1 can be easily disengaged from the outer container 2 when replacing it as a refill.

[0042] <Inner container manufacturing method (1)> Next, a manufacturing method for an inner container in the first embodiment will be described using Figures 5, 6A to 6E, 7A and 7B. Figure 5 is a flowchart of a first manufacturing method for an inner container of the present invention. Figures 6A to 6E are cross-sectional explanatory views showing the first manufacturing method for an inner container. Figures 7A and 7B are detailed explanatory views of the sheet and cutting position on a mold, showing the first manufacturing method for an inner container.

[0043] 6A to 6E, Fig. 6A is an explanatory diagram of step S11, and Fig. 6B is a top view of the mold M1 in Fig. 6A. Fig. 6C is a schematic explanatory diagram of step S12, Fig. 6D is a diagram of the container after a portion of the sheet has been formed into a container shape after step S12, and Fig. 6E is an explanatory diagram of step S14. Note that while Figs. 6A and 6C show the mold M1 in schematic form, in more detail, the mold M1 has different shapes in cross section A and cross section B, as shown in Figs. 6B, 7A, and 7B.

[0044] First, in step S11, a thin resin sheet S is heated (FIG. 6A). The thickness of the resin sheet S before heating is about 0.3 to 3.0 mm, and heating makes the sheet easier to stretch.

[0045] In step S12, the resin sheet S is brought close to the mold M1 and sucked from the underside of the mold M1, and vacuum and pressure molding is performed by air pressure or a pressing force from a plug from above the mold (FIG. 6C).

[0046] The details of the mold used in this molding process will be described with reference to Figures 6B, 7A, and 7B. In Figures 7A and 7B, Figure 7A is a cross-sectional view of Figure 6B taken along surface A and passing through the depending tab 17, and Figure 7B is a cross-sectional view of Figure 6B taken along surface B and not passing through the depending tab 17.

[0047] The mold M1 used in this manufacturing method has a recess R formed therein, and a protrusion P is provided around the recess R. In this embodiment, the recess R formed in the mold M1 is a recess with an upper polygonal prism shape and a lower downward-facing truncated cone shape, similar to the storage section of the inner container 1. Here, the amount of depression of the recess R in the mold M1 relative to the outside is larger than the amount of protrusion of the protrusion P relative to the outside, and is about 5 to 20 times larger.

[0048] The protrusion P provided around the recess R has a polygonal inner edge and a circular outer edge, and is generally annular in top view. Furthermore, part of the outer edge of the protrusion P is a narrow protrusion Pa that is recessed toward the inner diameter side. The outer surface of the narrow protrusion Pa, which is thinner on the outer diameter side than the other protrusions P, forms the hanging tab 17.

[0049] Furthermore, the mold M1 is formed with a plurality of thin holes H for evacuation. Of the vacuum holes H, the vacuum hole H1 on the lower side of the mold M1 is connected to the recess R, while the vacuum holes H2 (H2a, H2b) on the outer side are not connected to the recess R. Note that although FIGS. 6A and 6C show a configuration in which the vacuum holes H1 and H2 are connected within the mold M1, as shown in FIGS. 7A and 7B, the vacuum holes H1, H2a, and H2b may not be connected to each other and may extend independently to the lower end of the mold M1. Note that although the vacuum hole H2 is shown as a straight line in FIGS. 6A and 6C, the vacuum holes H2 (H2a, H2b) are curved outward at their upper ends and extend in detail as shown in FIGS. 7A and 7B. In accordance with the thickness of the protrusions Pa and P, the portion of the upper end of the vacuum suction hole H2a shown in FIG. 7A that extends laterally is shorter than the vacuum suction hole H2b shown in FIG. 7B.

[0050] Furthermore, as shown in FIG. 7A, the vacuum hole H2a branches upward and communicates with a depression Par on the outer peripheral surface of the protrusion Pa.

[0051] A thin resin sheet S is brought close to the mold M1 and suction is applied from below the mold M1, stretching the resin sheet S along the recessed portion R of the mold M1 to form the storage portion 10. Furthermore, the outside of the recessed portion R of the mold M1 is suctioned through vacuum holes H2a and H2b, stretching the resin sheet S along the protruding portions P and Pa of the mold M1. As a result, upper flanges 15S are formed above the upper surfaces of the protruding portions P and Pa, a hanging piece 17S is formed along the outer surface of the protruding portion Pa, and a temporary outer ring OR is formed along the outside of the protruding portion P. At this time, the portion of the resin sheet S facing the recessed portion Par of the protruding portion Pa is stretched by vacuum molding to form a protruding portion (inner surface) 18 that protrudes from the inner surface of the hanging piece 17S, resulting in a recessed outer surface. That is, the outer surface of the hanging piece 17S is recessed while the protruding portion 18 is formed on the inner surface. FIG. 6D shows a top perspective view of the resin container with an outer rim formed on the mold in this way.

[0052] In step S13, the molded container is punched and cut into a circular shape in top view (separation step). More specifically, as shown by the dotted lines in Fig. 6E and Figs. 7A and 7B, a portion slightly inside the outer edge of the protrusion P and outside the outer edge of the narrow protrusion Pa is cut into a circular shape in top view. As a result, the upper sides of the upper surfaces of the protrusion P and narrow protrusion Pa form the upper flange 15, and the outer surface of the narrow protrusion Pa forms the depending tab 17. By cutting into a circular shape in this manner, the molded upper flange 15 and depending tab 17 are separated together with the container 10 from the rest of the sheet, including the temporary outer ring OR.

[0053] In addition, the boundary with the outer ring OR and the difference in outer diameter between the convex portion P of the mold and the narrow convex portion Pa become the outer edge portion 17E, which is a bulge at the outer edge of the outer surface of the hanging tab 17, and is slightly thicker than the center of the outer surface of the hanging tab 17.

[0054] Furthermore, since the sheet deforms more in the storage section 10 molded along the recessed section R than in the upper flange 15 and the hanging tab 17 molded along the protruding sections P and Pa, the bottom surface 11 and side surface sections 12 constituting the storage section 10 are thinner than the upper flange 15 and the hanging tab 17. For example, if the thickness of the thin sheet S before molding is 1, the thickness of the storage section 10 is 0.05 to 0.9, and the thickness of the upper flange is about 0.5 to 0.95. In other words, the thickness of the storage section 10 is about 1 / 10 to 19 / 20 of the thickness of the upper flange 15.

[0055] In step S14, the cut inner container 1 is released from the mold (demolded).

[0056] The inner container formed by the above process is made of a thin sheet, for example, 0.3 to 3.0 mm thick. After forming, the thickness of the upper flange 15 is 0.15 to 2.85 mm, and the thicknesses of the side wall 12 and bottom wall 11 are 0.015 to 2.7 mm.

[0057] However, with containers of a thickness that can be produced by conventional injection molding, variations in the thickness of the glass container can cause the fit to be too tight or too loose, resulting in easy separation. However, the inner container molded from a thin sheet as described above uses less resin than conventional injection-molded containers due to its thinness, and is soft and highly flexible. Therefore, even if the outer container is molded from glass, which is prone to manufacturing variations, the inner container can easily adapt to molding variations and fit, thereby preventing the above problems from occurring.

[0058] Furthermore, in this embodiment, a hanging tab 17 is provided connected to the upper flange 15 of the formed inner container housing, and a projection 18 for engagement is formed on the hanging tab 17, thereby enabling secure engagement with the outer container. As a result, even if the upper flange 15 comes into close contact with the packing 5 after, for example, a typhoon or other sudden change in air pressure around the capped double container, or after the container is turned upside down, the double container will maintain its engaged state without rotating together with the cap 4.

[0059] On the other hand, in this configuration, when the container is double-walled, the hanging tab 17 of the inner container 1 is positioned opposite the thin-walled mouth portions 27A, 27B of the outer container 2, so even if the storage section 10 of the inner container 1 is sized to fit snugly with the outer container 2, when removal is intended, the inner container can be easily removed from the outer container 2 by applying direct force to the lower end of the hanging tab 17.

[0060] 8 is a perspective view of an inner container according to a second embodiment of the present invention. The inner container 1α of this embodiment differs from the first embodiment in that the hanging tab 17α does not have an outer edge 17E that protrudes toward the outer diameter side. The rest of the shape is the same as that of the inner container 1 of the first embodiment.

[0061] <Inner container manufacturing method (2)> Next, a manufacturing method for the inner container 1α in the second embodiment will be described using Figure 9 and Figures 10A to 10D. Figure 9 is a flowchart of a second manufacturing method for the inner container of the present invention. Figures 10A to 10D are cross-sectional explanatory views showing the second manufacturing method for the inner container. Only the differences from the first manufacturing method will be described below.

[0062] 10A to 10D, FIG. 10A is an explanatory diagram of step S21, FIG. 10B is a top view of mold M2 in FIG. 10A, FIG. 10C is a schematic explanatory diagram of step S22, and FIG. 10D is an explanatory diagram of secondary processing in step S25.

[0063] First, in step S21, a thin resin sheet S is heated in the same manner as described above. Then, in step S22, the resin sheet S is brought close to a mold M2 and sucked from the underside of the mold M2, and vacuum and pressure-molded by air pressure or a plug pressure from above the mold (FIG. 10C).

[0064] The details of the mold used in this molding process will be described with reference to Figures 10B and 10C. Figure 10C is a cross-sectional view of the plane A of Figure 10B, passing through horizontal tab 17H in the stage preceding the depending tab 17.

[0065] The mold M2 used in this manufacturing method has a recess R1 formed therein. The recess R1 formed in the mold M2 of this embodiment is a recess with an upper polygonal prism shape and a lower downward-facing truncated cone shape, similar to the storage section of the inner container 1.

[0066] Two band-shaped recesses R2 are provided extending in two opposing directions so as to communicate with the recess R1. The band-shaped recesses R2 are provided with grooves R2r extending in the width direction. An annular recess R3 is provided around the recess R1 in the area other than the band-shaped recesses R2.

[0067] Furthermore, the mold M2 used in this manufacturing method is formed with multiple thin holes H for vacuuming. Of the vacuum holes H, the vacuum hole H1 on the lower side of the mold M2 is connected to the recess R1, while the vacuum hole H3 on the outer side is not connected to the recess R1. While FIGS. 10A and 10C show a configuration in which the vacuum holes H1 and H3 are connected within the mold M2, the vacuum holes H1 and H3 may not be connected and may extend independently to the lower end of the mold M2. The vacuum hole H3 extends, bending upward at its upper end. Although not shown, a vacuum hole similar to H2b in FIG. 7B is also provided below the annular recess R3. The sheet formed in this manner has a horizontal tab 17H, as shown in FIG. 10B, in which a tab portion protrudes from a circular shape when viewed from above. Specifically, the molded container has a storage portion 10 formed along the recess R1, an upper flange 15 above the annular recess R3, and a horizontal tab 17H above the band-shaped groove R2. Because the resin sheet S that forms the horizontal tab 17H has a uniform thickness, the horizontal tab 17H is pulled along the groove R2r of the mold M2 by vacuum molding to form a protrusion 18 that protrudes from the lower surface, resulting in a recess in the outer upper surface. That is, the upper surface of the horizontal tab 17H is recessed, while a protrusion is formed on the lower surface.

[0068] In step S23, the molded container is punched and cut so as to include the tab portion, that is, the portion that protrudes from the circular shape in top view. Specifically, the cut is made along the outer edge of the upper flange 15 and the outer edge of the horizontal tab 17H.

[0069] Thereafter, in step S24, the cut container is sucked from above, and the container is separated from the mold (de-molded).

[0070] Then, in step S25, the tab portion is folded and shaped by secondary processing to complete the container (see FIG. 10D). Specifically, the boundary between horizontal tab 17H and upper flange 15 is folded to turn horizontal tab 17H into hanging tab 17. Note that by folding horizontal tab 17H, protrusion 18, which was located on the underside before processing, is now located on the inner surface of hanging tab 17.

[0071] Both the containers formed by the first and second manufacturing methods are provided with a hanging tab. Therefore, even if the inner and outer containers of the double-layered container are tightly attached, they can be easily removed by applying force to the hanging tab. On the other hand, even if the upper flanges of the cap and the gasket are tightly attached due to changes in air pressure, temperature, humidity, etc., the hanging tab fits into the thin-walled portion, preventing the inner container from rotating together with the cap and from coming off.

[0072] Third Embodiment FIG. 11 is a bottom perspective view of an inner container according to a third embodiment of the present disclosure.

[0073] The inner container 1β of this embodiment has a cylindrical body. Specifically, the side surface 12β of the inner container 1β has a lower, tapered side surface 13β that is circular in cross section at the top and decreases in diameter downward, and an upper, cylindrical side surface 14β. Therefore, in this embodiment, the upper flange 15β of the body has an annular shape with both the inner and outer edges being circular.

[0074] The inner container 1β of this embodiment is also manufactured by the first manufacturing method shown in Fig. 5. In the inner container 1β shown in Fig. 11, an outer edge 17E is provided on the hanging tab 17, but an inner container 1β having a cylindrical body may be formed by the second manufacturing method shown in Fig. 9, and may not have the outer edge 17E.

[0075] In this embodiment, the inner container 1β is also provided with a hanging tab 17. As shown in Figure 3, the inner container 1β of this embodiment also engages with an outer container 2 having thin-walled mouth portions 27A and 27B to form a double-walled container. Therefore, even if the inner container 1β is tightly attached to the outer container, force is applied to the hanging tab 17, allowing the inner container 1β to be easily removed. Furthermore, even if the upper flanges of the cap and the packing are tightly attached to each other due to changes in air pressure, temperature, humidity, etc., the fitting of the hanging tab into the thin-walled portion prevents the inner container from rotating together with the cap and from coming off together with the cap.

[0076] (Variant) In the above example, no hanging portion is provided on the outer edge of the upper flange other than the hanging tab 17, but an annular ring (peripheral ring) shorter than the hanging tab 17 may be provided on a portion other than the hanging tab 17.

[0077] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the embodiments of the present invention described in the claims.

[0078] This application claims priority based on Japanese Patent Application No. 2024-000275, filed on January 4, 2024, the entire contents of which are incorporated herein by reference.

[0079] DESCRIPTION OF SYMBOLS 1, 1α, 1β Inner container 10, 10α Storage section 11 Bottom surface 12, 12β Side surface 13, 13β Diameter-reducing side surface 14 Polygonal cylindrical side surface 14β Cylindrical side surface 15, 15β Upper end flange 17, 17α Hanging tab 18 Convex portion on inner surface 2 Outer container 20 Case portion 21 Bottom wall 22 Side wall 23 Mouth portion (cylindrical mouth portion) 24A, 24B Thick-walled portion of mouth portion (thick-walled portion) 25 Screw projection 26 Annular protrusion 27A, 27B Thin-walled portion of mouth portion (thin-walled portion) 28 Shoulder portion 3 Double container 4 Cap 5 Gasket (sealing material) 6 Double container with cap M1, M2 Mold

Claims

1. A double container having an outer container and an inner container that is removably accommodated as a refill in the outer container, wherein the outer container has a bottom wall, a side wall, and a cylindrical mouth portion located above the side wall, the inner container has a bottom surface, a side surface portion, an upper end flange that projects radially outward from the entire circumference of the upper end of the side surface portion, and a hanging tab that hangs down from the outer edge of the upper end flange, a thin portion is provided at the mouth portion of the outer container, in a state of the double container with the inner container mounted in the outer container, the upper end flange of the inner container is located above the upper end of the mouth portion of the outer container, and the hanging tab is located outside the thin portion, the inner container is a double container made of a resin sheet material.

2. A convex portion is formed on the inner surface of the hanging tab of the inner container, an engaging portion is provided on the outer surface of the thin portion of the outer container, in a state of the double container with the inner container mounted in the outer container, the convex portion on the inner surface of the hanging tab engages with the engaging portion of the thin portion. The double container according to claim 1.

3. The double container according to claim 1, wherein at least the outer periphery of the upper part of the side surface portion of the inner container is polygonal.

4. The double container according to claim 1, wherein at least the outer periphery of the upper part of the side surface portion of the inner container is cylindrical.

5. Two or more hanging tabs are provided on the inner container, at the mouth portion of the outer container, the inner surface is a continuous circumferential surface, and a thick portion having a large radial thickness from the inner surface and a thin portion that is recessed stepwise in the radial direction from the end of the thick portion and is shorter in the circumferential direction than the thick portion are alternately provided. The double container according to any one of claims 1 to 4.

6. A refill container that is removably accommodated in an outer container having a cylindrical mouth portion, wherein the refill container includes a bottom surface, a side surface portion, an upper end flange that projects radially outward from the entire circumference of the upper end of the side surface portion, and a hanging tab that hangs down from a part of the outer edge of the upper end flange, the refill container is a refill container made of a resin sheet material.

7. A method for manufacturing a refill container that is removably accommodated in an outer container, the method comprising: setting a resin sheet material in a mold having a recess; forming the sheet material into a container shape by vacuum and pressure molding the mold; separating the formed refill container by punching; and a mold release step of removing the separated refill container from the mold. In the mold, a substantially annular convex portion that protrudes from the outer portion with a predetermined width is formed at the peripheral edge of the recess, and a part of the outer edge of the convex portion is a narrow convex portion that is recessed inward on the inner diameter side. In the separating step, by cutting out a portion that is slightly inside the outer edge of the convex portion and outside the outer edge of the narrow convex portion in a circular shape in a top view, an upper end flange is formed by the upper side of the upper surface of the convex portion and the narrow convex portion, and a hanging tab is formed by the outer surface of the narrow convex portion. A method for manufacturing a refill container.

8. In the thin portion of the mold, a recess is formed in the outer peripheral surface of the recess, which is the end point of the vacuum suction hole. In the forming step, a convex portion is formed on the inner surface while the outer surface is recessed in a portion of the hanging tab that faces the recess. The method for manufacturing a refill container according to claim 7.

9. A method for manufacturing a refill container that is removably accommodated in an outer container, the method comprising: setting a synthetic resin sheet material in a mold having a recess; forming the sheet material into a container shape by vacuum and pressure molding the mold; separating the outside of the refill container by punching; a mold release step of removing the separated refill container from the mold; and a secondary processing step of bending a part of the released refill container. In the mold, the peripheral edge of the recess is an annular recess that is recessed annularly from the outer portion, and a strip-shaped groove portion is formed outside the recess by a part of the outer edge of the annular recess protruding outward. In the formed container, the upper side of the annular recess becomes the upper end flange, and the upper side of the strip-shaped groove portion becomes the horizontal tab. In the separating step, it is cut out in a circular shape in a top view along the outer edge of the upper end flange and the outer edge of the horizontal tab. In the secondary processing step, the portion at the boundary between the horizontal tab and the upper end flange is bent to make the horizontal tab a hanging tab. A method for manufacturing a refill container.

10. In the mold, a concave portion is formed on the upper surface of the strip-shaped groove portion. In the step of molding, a convex portion is formed on the lower surface while the upper surface is recessed at a portion of the horizontal tab facing the concave portion. By bending in the secondary processing step, the convex portion on the lower surface of the horizontal tab becomes the convex portion on the inner surface of the hanging tab. The method for manufacturing a refill container according to claim 9.

Images