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

Abstract

In a double container 3 having an outer container 2 and an inner container 1 housed in a replaceable manner as a refill, the outer container 2 has a bottom wall 21, a side wall 22, a shoulder part 23 extending from an upper end of the side wall 22 to an outer diameter side, and a cylindrical opening part 24 positioned above the shoulder part 23 and having a diameter smaller than that of the side wall 22, and the inner container 1 has a bottom surface 11, a trunk part 12 formed from a lower side surface 13 and an upper side surface 14, and an upper end flange 15 protruding radially outward from an entire periphery of an upper end of the upper side surface 14. In the trunk part 12 of the inner container 1, the diameter of the lower side surface 13 is larger than the diameter of the upper side surface 14. The inner container 1 is composed from a resin sheet material. In the state of the double container in which the inner container 1 is attached to the outer container 2, the upper end flange 15 of the inner container 1 is positioned above the upper end of the opening part 24 of the outer container 2, and the length from the upper end of the upper side surface 14 of the inner container 1 to the step of the boundary between the upper side surface 14 and the lower side surface 13 is longer than the length of the opening part 24 of the outer container 2.

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 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 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] JP 2023-28030 A

[0004] However, some outer containers of double-walled containers, such as wide-mouth glass outer containers produced by blow molding, have a larger body diameter than the mouth diameter. When an inner container with a straight side surface in cross section is fitted into an outer container of this shape, a large space is created between the housing portion of the outer container and the outer peripheral surface of the side surface of the housing portion of the inner container, and this space becomes dead space.

[0005] In view of the above circumstances, the present invention has an object to provide a double container in which dead space is reduced when the diameter of the side wall of the outer container is larger than the diameter of the opening.

[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 can be stored in the outer container as a refill, wherein the outer container has a bottom wall, side walls, a shoulder that extends outward from the upper end of the side wall, and a tubular mouth that is located on the shoulder and has a diameter smaller than that of the side wall, the inner container has a bottom, a body consisting of lower and upper side surfaces, and an upper end flange that protrudes radially outward from the entire circumference of the upper end of the upper side surface, the diameter of the lower side surface of the body of the inner container is larger than the diameter of the upper side surface, the inner container is made of a resin sheet material, and when the inner container is attached to the outer container, the upper end flange of the inner container is located above the upper end of the mouth of the outer container, and the length from the upper end of the upper side surface of the inner container to the step at the boundary with the lower side surface is longer than the length of the mouth of the outer container.

[0007] According to one aspect, in a double container, when the diameter of the side wall of the outer container is larger than the diameter of the opening, the dead space can be reduced.

[0008] FIG. 1 is a cross-sectional view of a double container according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view of a double container with a cap according to the first embodiment. FIG. 3 is a bottom perspective view of an inner container according to the first embodiment. FIG. 4 is a flowchart of a method for manufacturing an inner container according to the first embodiment. FIG. 5 is an explanatory view showing a method for manufacturing an inner container according to the first embodiment. FIG. 6 is an explanatory view showing a method for manufacturing an inner container according to the first embodiment. FIG. 7 is a perspective view of an inner container according to a second embodiment of the present invention. FIG. 8 is a perspective view of an inner container according to a third embodiment of the present invention. FIG. 9 is a cross-sectional view of a double container having an inner container according to a modified example of the present invention. FIG. 10 is a cross-sectional view of a double container having an inner container according to a modified example 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 container, particularly a double container for storing a viscous or solid substance. The inner container of the double container is a sheet-formed resin container, which may or may not be self-supporting. The outer container of the double container is a self-supporting container, preferably made of glass, but may also be made of wood, resin, silicone, metal, 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 substance or solid substance is filled into the storage section in advance as a refill (refill container) by replacing the entire inner container. Alternatively, the viscous substance or solid substance may be filled into the inner container while the inner container is set in the outer container during manufacturing.

[0014] <First embodiment> First, the overall configuration of a double container according to a first embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a cross-sectional view of a double container according to a first embodiment of the present invention. Figure 2 is an exploded perspective view of a double container with a cap according to the present invention. Figure 3 is a perspective view of the bottom of an 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 1 and 2 has a wide-mouthed, low-profile jar shape. The double container 3 can be engaged with a cap 4 (see Figure 2).

[0016] In this embodiment, the inner container 1 comprises a cylindrical storage portion 10 with a bottom, which has a bottom surface 11 and a body portion 12 , and an upper end flange 15 that projects outward from the upper end of the storage portion 10 .

[0017] The body 12 of the inner container 1 has a lower side surface 13 with a larger diameter and an upper side surface 14 with a smaller diameter than the lower side surface 13. For example, the diameter ratio of the lower side surface 13 to the upper side surface 14 depends on the ratio of the inner diameter of the mouth portion 24 of the outer container 2 to the inner diameter of the side wall 22 of the case portion 20, but for example, the diameter of the lower side surface 13 is about 1.05 to 1.2 times the diameter of the upper side surface 14.

[0018] 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.

[0019] 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 23 is provided at the upper end of the case portion 20, extending radially outward from the entire circumference of the upper end of the side wall 22, and a cylindrical mouth portion 24 is provided that extends upward from the inner edge of the shoulder portion 23. As shown in Figures 1 and 2 , the cylindrical mouth portion 24 has a smaller diameter than the side wall 22 of the case portion 20 and is located more inward than the side wall 22.

[0020] The outer peripheral surface of the mouth 24 is provided with a screw projection 25 at the top and an annular ridge 26 extending in the circumferential direction. The screw projection 25 of the outer container 2 threadably engages with a screw projection (not shown) of the cap 4. The annular ridge 26 is located below the screw projection 25, and the cap 4 engages with it so that it covers the annular ridge 26. The annular ridge 26 may 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.

[0021] The length L14 from the top end of the upper side surface 14 of the inner container 1 to the step at the boundary with the lower side surface is longer than the length L24 of the mouth of the outer container. As a result, when the inner container 1 is set as a double container 3, as shown in Figure 1, the position of the outer outer diameter step OS where the diameter of the body 12 of the inner container 1 changes is located below the inner step IS, which is the position of the boundary between the side wall 22 and the mouth 24 of the outer container 2.

[0022] The outer diameter OR13 of the lower side surface 13 of the inner container 1 is larger than the narrowest inner diameter IR24 of the opening 24 of the outer container 2.

[0023] With these configurations, when the double container 3 is in a state where the space inside the side wall 22 of the outer container 2 is in a state where it is surrounded by the lower side surface 13 of the inner container 1, the portion of the space inside the side wall 22 of the outer container 2 is wider horizontally than the inner diameter of the mouth 24, so that dead space is reduced, the space can be used effectively, and the capacity of the contents that can be stored in the inner container 1 can be increased.

[0024] The outer container 2 of the present invention is preferably made of glass, but may also be made of resin, glass, wood, silicon, 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.

[0025] 2, 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. 2, 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.

[0026] 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 24 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.

[0027] 2, 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).

[0028] When the cap 4 engages with the double container 3, the screw projections 25 on the opening 24 of the outer container 2 and the screw projections on the cap 4 are threadedly engaged. At this time, the gasket 5 is engaged while being sandwiched between the underside of the top surface 41 of the cap 4 and the upper flange 15 of the inner container 1. When the cap 4 and the double container 3 are engaged with the elastic gasket 5 sandwiched between them, the contents will not leak even if the double container 3 is tilted or turned upside down.

[0029] 2, 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.

[0030] 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.

[0031] 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.

[0032] 2, 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 24 of the outer container 2. Therefore, the radial width of the upper flange 15 of the inner container 1 is the same size as or wider than the width of the mouth 24 of the outer container 2.

[0033] When engaging the inner container 1 configured as above with the outer container 2, the user pushes the upper end flange 15 of the inner container 1 from above, pushing it into the outer container 2. At this time, the lower side surface 13 of the body 12 of the inner container 1 deforms and moves over the inner step IS of the outer container 2, and the lower side surface 13 of the inner container 1 enters inside the side wall 22 of the case part 20 of the outer container 2.

[0034] Conversely, when removing the inner container 1 for replacing the refill, the user puts his / her fingers on the upper end flange 15 and lifts it up, causing the lower side surface 13 of the body 12 of the inner container 1 to deform and climb over the inner step IS of the outer container 2, thereby separating the inner container 1 from the outer container 2.

[0035] The inner container 1 of the present invention is formed by sheet molding a thin resin sheet. Because it is thin and easily deformable, even if the outer diameter OR13 of the lower side surface 13 of the inner container 1 is larger than the inner diameter IR24 of the narrowest part of the mouth 24 of the outer container 2, the inner container 1 can temporarily deform to overcome this and be attached or detached.

[0036] As a result, the diameter of the lower side surface 13 of the inner container 1 is large in correspondence with the thickness of the side wall 22 of the case part 20, which is thicker than the mouth part 24 of the outer container 2, thereby reducing the dead space of the outer container 2 in the double container 3. Note that while Fig. 1 shows an example in which the bottom surface 11 of the inner container is separated from the bottom wall 21 of the outer container 2 when the double container 3 is engaged, the bottom surface 11 of the inner container may also be in contact with the upper surface of the bottom wall 21 of the outer container 2, in which case the dead space of the outer container can be further reduced.

[0037] In addition, since the lower side surface 13 of the body 12 of the inner container 1 deforms when it is attached to or detached from the outer container 2, it is preferable to take the amount of deformation into consideration and not to fill the inner container 1 to the very top, but to leave a margin of about 0.05% to 20% of the total volume of the storage section 10.

[0038] <Manufacturing of inner container> Next, a manufacturing method of the inner container in the first embodiment will be described with reference to Figure 4 and Figures 5A to 5C. Figure 4 is a flowchart of the manufacturing method of the inner container of the present invention. Figures 5A to 5C are explanatory diagrams showing the manufacturing method of the inner container.

[0039] 5A to 5C, FIG. 5A is an explanatory diagram of the mold in step S1, FIG. 5B is a diagram showing the molding in step S2, and FIG. 5C is a top view showing the punching position in step S3.

[0040] First, in step S1, a thin resin sheet S is heated (FIG. 5A). 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.

[0041] In step S2, the resin sheet S is brought close to the mold M and sucked from below the mold M, and vacuum and pressure molding is performed using air pressure or a pressing force from a plug from above the mold (FIG. 5B).

[0042] 5A and 5B, the mold M used in this manufacturing method has a recess R formed therein. Similar to the storage section 10 of the inner container 1, the recess R formed in the mold M has a larger diameter at the bottom than at the top, with the bottom being a large-diameter space rl and the top being a small-diameter space rs.

[0043] Furthermore, a plurality of thin holes for vacuuming are formed in the mold M. Of the vacuum holes, the vacuum hole H1 on the lower side of the mold M is in communication with the lower surface of the large diameter space rl of the recess R, and the vacuum hole H2 on the outer side is in communication with a stepped portion on the side surface at the boundary between the large diameter space rl and the small diameter space r2 of the recess R. Note that although Figures 5A and 5B show a configuration in which the vacuum holes H1 and H2 are independent up to the bottom end of the mold M, the vacuum holes H1 and H2 may extend to meet partway through the mold M.

[0044] A thin resin sheet S is brought close to a mold M and sucked from below the mold M, whereby the resin sheet S is stretched along the recess R of the mold M to form the storage section 10. At this time, the portion that was in contact with the side surface of the large diameter space r1 becomes the lower side surface 13 of the body of the storage section 10, and the portion that was in contact with the side surface of the small diameter space r2 becomes the upper side surface 14.

[0045] In step S3, the molded container is punched and cut into a circular shape in top view (separation step). At this time, as shown in Fig. 5C, by cutting a ring shape slightly outside the recess R, the upper end flange 15 is separated from the other parts of the molded sheet together with the storage portion 10.

[0046] Here, in the sheet forming process using a mold, the storage section 10 formed along the recess R deforms more than the upper flange 15 around the recess R, so the bottom surface 11 and body 12 that make up the storage section 10 are thinner than the upper flange 15. For example, if the thickness of the thin sheet S before forming 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.

[0047] In step S4, the cut inner container 1 is released from the mold M (demolded).

[0048] The inner container formed by the above process is made from 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 body 12 and bottom 11 are 0.015 to 2.7 mm. In the formed container 10, the lower side surface 13 has a larger diameter than the upper side surface 14, so the sheet deforms more, and the lower side surface 13 becomes slightly thinner than the upper side surface 14.

[0049] 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.

[0050] Furthermore, the outer diameter OR13 of the lower side surface 13 of the molded storage section 10 of the inner container 1 is larger than the narrowest inner diameter IR24 of the opening 24 of the outer container 2. Therefore, even if the double container 3 is accidentally knocked over, the step OS of the body 12 of the inner container 1 will catch on the opening 24 of the outer container 2, making it difficult for the inner container 1 to unintentionally come off from the outer container 2.

[0051] On the other hand, when removing the inner container 1 from the double container state, the user grasps the outer container 2 and pulls it upward by the upper flange 15, causing the lower side surface 13 to deform and overcome the inner step IS of the mouth portion 24, thereby disengaging the engagement.

[0052] Second Embodiment Next, the configuration of a second embodiment will be described with reference to Fig. 6. Fig. 6 is a perspective view of an inner container according to a second embodiment of the present invention.

[0053] In the inner container 1A of this embodiment, the outer surface of the lower side surface 13A of the body 12A of the container section is provided with a plurality of vertically extending grooves 16, giving it a so-called bellows structure in the circumferential direction. In this embodiment, too, the diameter of the lower side surface 13A of the body 12A of the inner container 1A is larger than the diameter of the upper side surface 14.

[0054] Furthermore, in the inner container 1A of this embodiment, the length of the upper side surface 14 is also longer than the length of the mouth of the outer container with which it is engaged. Therefore, when the inner container 1A is engaged with the outer container 2 in Figures 1 and 2 to form a double-walled container, the position of the step OSA where the diameter of the body 12A of the inner container 1A changes is located below the position of the step IS between the side wall 22 and the mouth 24 of the outer container 2. The outer diameter of the lower side surface 13 of the inner container 1 is larger than the narrowest inner diameter IR24 of the mouth 24 of the outer container 2. This configuration reduces dead space within the space of the case portion of the outer container, allowing for effective use of space and increasing the capacity of the contents to be accommodated in the inner container.

[0055] Furthermore, in this embodiment, the grooves 16 are provided on the lower side surface 13A, which is made of a thin sheet, so that the lower side surface 13A is more likely to deform when it overcomes the inner step IS between the mouth and side wall of the outer container when attaching or detaching the inner container 1A to or from the outer container 2. This reduces the resistance when inserting the storage section of the inner container 1A into the outer container 2.

[0056] When the inner container shown in Fig. 6 is molded from sheet material as shown in Figs. 5A to 5C, multiple ribs extending in the vertical direction are provided on the inner surface of the side surface of the large diameter space r1 below the recess R of the mold. As a result, when the heated sheet is molded, the portions corresponding to the ribs of the mold become multiple grooves.

[0057] Third Embodiment Next, the configuration of a third embodiment will be described with reference to Fig. 7. Fig. 7 is a perspective view of an inner container according to a third embodiment of the present invention.

[0058] In the inner container 1B of this embodiment, the outer surface of the lower side surface 13B of the body 12B of the container section has a wavy polygonal shape with rounded corners. The wavy shape is a flower-like shape (like a so-called African flower) in which the corners of the polygon are rounded and the centers of each side of the polygon are concave inward. The polygon that forms the wavy shape is preferably a regular 4 to 24-sided polygon.

[0059] In the lower side surface 13B of the inner container 1B of this embodiment, in a cross-sectional view, at least the diagonal line passing through the outwardly protruding corners of the rounded polygon is larger than the diameter of the upper side surface 14. Also, in this embodiment, the length of the upper side surface 14 is longer than the length of the mouth 24 of the mating outer container 2. Therefore, when the inner container 1B of this embodiment is engaged with the outer container 2 in the double-container state shown in Figures 1 and 2, the step OSB where the diameter of the body 12B of the inner container 1B changes is located below the step IS between the side wall 22 and the mouth 24 of the outer container 2. This configuration reduces dead space within the space of the side wall 22 of the outer container 2, allowing for effective use of space and increasing the capacity of the contents held in the inner container 1B. Furthermore, even if the double-container 3 is overturned, the step OSB of the body 12B of the inner container 1B catches on the mouth 24 of the outer container 2, making it difficult for the inner container 1B to unintentionally detach from the outer container 2.

[0060] Furthermore, in this embodiment, the lower side surface 13B, which is made of a thin sheet and has a wavy polygonal shape, is easily deformed when the lower side surface 13B passes over the inner step IS of the outer container 2 during attachment / detachment of the inner container 1B to / from the outer container 2, as the recessed portions of the wavy shape of the lower side surface 13B fold inward. This reduces the resistance when inserting the storage section of the inner container 1B into the outer container 2.

[0061] 7 is formed from a sheet material as shown in FIGS. 5A to 5C, the large-diameter space r1 below the recess R of the mold has a polygonal wavy cross section. As a result, when the heated sheet is formed, the portion corresponding to the wavy shape of the large-diameter space r1 of the mold becomes a polygonal wavy lower side surface 13B.

[0062] In the above example, as an inner container having stepped side surfaces with different diameters, as shown in Fig. 1, the upper side surface is linear from top to bottom across the entire cross section, and the lower side surface is linear except for the area near the bottom, with the diameter barely changing in each area. However, as long as the upper side surface is a linear cylindrical shape in cross section, the lower side surface may have a different shape. Figures 8A and 8B are cross-sectional views of double containers having inner containers according to modified examples.

[0063] (Modification 1) As an example, the body 12C of the inner container 1C may have a shape in which the center of the lower side surface 13C bulges out into a substantially spherical shape, like a round-bottom flask shown in FIG. 8A.

[0064] In the inner container 1C of this configuration, the outer diameter OR13C passing through at least the most outwardly bulging portion of the substantially spherical lower side surface 13C is larger than the inner diameter IR24 of the mouth 24 of the mating outer container 2. Furthermore, in this configuration, the length of the upper side surface 14 is also longer than the length of the mouth 24 of the mating outer container 2. Therefore, when the double container 3C is engaged with the outer container 2, the step OSC where the diameter of the inner container's body 12C changes is located below the inner step IS of the outer container. These configurations reduce dead space within the sidewall 22 of the outer container 2, allowing for effective use of space and increasing the capacity of the contents held in the inner container 1C. Furthermore, even if the double container 3C is accidentally toppled, the step OSC of the body 12C of the inner container 1C and the bulge of the lower side surface 13C catch on the mouth 24 of the outer container 2, making it less likely for the inner container 1C to unintentionally detach from the outer container 2.

[0065] (Variation 2) Alternatively, the lower side surface 13D of the inner container 1D may have a larger diameter at the upper side near the boundary with the upper side surface 14 and a smaller diameter at the lower end, for example, like the shape of the storage section of the outer container in FIG. 1 (see FIG. 8B).

[0066] In the inner container 1D of this configuration, the outer diameter OR13D passing through the uppermost outwardly protruding end of the lower side surface 13D is larger than the inner diameter IR24 of the opening 24 of the mating outer container 2. Furthermore, in this embodiment, the length of the upper side surface 14 is also longer than the opening 24 of the mating outer container 2. Therefore, when the double container 3D is mated with the outer container, the step OSD where the diameter of the body 12D of the inner container 1D changes is located below the inner step IS of the outer container 2. These configurations reduce dead space within the sidewall 22 of the outer container 2, allowing for effective use of space and increasing the capacity of the contents held in the inner container 1D. Furthermore, even if the double container 3D is accidentally toppled, the step OSD of the body 12D of the inner container 1D catches on the opening 24 of the outer container 2, making it less likely for the inner container 1D to unintentionally detach from the outer container 2.

[0067] (Variation 3) In the above example, the inner container is provided with only an upper ring, but the upper ring may be provided with hanging tabs that hang down from a part of its outer edge. In this case, it is preferable that the opening of the outer container be provided with vertically elongated thin-walled portions that are thin on the outer diameter side, the number of which is equal to the number of hanging tabs.

[0068] (Variation 4) Alternatively, the inner container may be provided with an outer ring that hangs down around the entire outer edge of the upper ring. In this case, it is preferable that the opening of the outer container has a thin upper portion that is thinner near the upper end.

[0069] 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.

[0070] This application claims priority based on Japanese Patent Application No. 2023-219988, filed on December 26, 2023, the entire contents of which are incorporated herein by reference.

[0071] DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D Inner container 10 Storage section 11, 11C, 11D Bottom surface 12, 12A, 12B, 12C, 12D Body 13, 13A, 13B, 13C, 13D Lower side surface 14 Upper side surface 15 Upper flange 16 Groove 2 Outer container 20 Case 21 Bottom wall 22 Side wall 23 Shoulder 24 Mouth portion (cylindrical mouth portion) 25 Screw projection 26 Annular ridge 3, 3C, 3D Double container 4 Cap 5 Gasket (sealing material) 6 Double container with cap L14 Length of upper side surface L24 Length of mouth OR13, OR13C, OR13D Outer diameter of lower side surface IR24 Inner diameter of mouth OS Step at the body of the inner container (external step) IS Step at the boundary between the mouth and side wall of the outer container (internal step)

Claims

1. A double container having an outer container and an inner container that is replaceably accommodated as a refill in the outer container, wherein the outer container has a bottom wall, a side wall, a shoulder extending outward in the diameter direction from the upper end of the side wall, and a cylindrical mouth portion located above the shoulder and having a smaller diameter than the side wall, the inner container has a bottom surface, a body portion composed of a lower side surface and an upper side surface, and an upper end flange protruding radially outward from the entire circumference of the upper end of the upper side surface, in the body portion of the inner container, the diameter of the lower side surface is larger than the diameter of the upper side surface, the inner container is composed of a resin sheet material, in the state of the double container in which the inner container is mounted on 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 length of the upper side surface of the inner container from the upper end to the step at the boundary with the lower side surface is longer than the length of the mouth portion of the outer container. Double container.

2. The double container according to claim 1, wherein the outer diameter of the lower side surface of the inner container is larger than the inner diameter of the portion with the smallest diameter of the mouth portion of the outer container.

3. The double container according to claim 1, wherein in the body portion of the inner container, the outer diameter of the lower side surface is 1.05 to 1.2 times the outer diameter of the upper side surface.

4. In the inner container, the thickness of the upper end flange is 0.15 to 2.85 mm, the thickness of the body portion and the bottom surface is 0.015 to 2.7 mm, and in the body portion, the thickness of the lower side surface is thinner than the thickness of the upper side surface. The double container according to claim 1.

5. The double container according to claim 1, wherein a plurality of groove portions extending in the vertical direction are formed on the outer side surface of the lower side surface of the inner container.

6. The lower side surface of the inner container is any one of a wavy flower shape in which the corners of the polygon are rounded and the center of each side of the polygon is recessed inward, a shape in which the center in the vertical direction of the inner container bulges spherically, or a shape in which the upper side near the boundary with the upper side surface has a larger diameter and the lower end side has a smaller diameter. The double container according to claim 1.

7. A refill container that is removably accommodated in an outer container having a mouth portion with a diameter smaller than that of the side wall, the refill container having a bottom surface, a body portion composed of a lower side surface and an upper side surface, and an upper end flange that protrudes radially outward from the entire circumference of the upper end of the upper side surface. In the body portion, the diameter of the lower side surface is larger than the diameter of the upper side surface, and the length of the upper side surface from the upper end to the step at the boundary with the lower side surface is longer than the length of the mouth portion of the outer container. The refill container is a refill container composed of a resin sheet material.

8. A method for manufacturing a refill container that is removably accommodated in an outer container, the method including a step of heating a resin sheet material, a step of forming the sheet material into a container shape by vacuum and pressure molding using a mold with a recess formed therein, a step of punching out and separating the formed container-shaped sheet in a circular shape outside the recess of the mold in a top view, and a mold release step of separating the formed container from the mold. In the mold used in the forming step, the lower part has a larger diameter than the upper part on the side surface of the recess, so that the formed container has a housing portion with a two-stage side surface where the lower side surface is larger in diameter than the upper side surface. In the separating step, the upper side around the recess is used as an upper end flange, and together with the housing portion, it is separated from other parts. A method for manufacturing a refill container.

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