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 which is accommodated in said outer container 2 so as to be replaceable as a refill. The outer container 2 has a bottom wall 21, a side wall 22, and a cylindrical mouth part 24 that is positioned over the side wall 22. The inner container 1 has a bottom surface 11, a side surface part 12, and an upper end flange 15 that protrudes radially outward from the whole periphery of an upper end part of the side surface part 12. The inner container 1 is composed of a sheet material made of a synthetic resin. The upper end flange 15 of the inner container 1 is positioned on the upper end of the mouth part 24 of the outer container 2 in a state of the the double container 3 in which the inner container 1 is fitted in the outer container 2, and the outer periphery of at least the upper part of the side surface part 12 of the inner container 1 is polygonal in shape.

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 light of the Sustainable Development Goals (SDGs), the use of double-layered containers with replaceable inner containers has become widespread in the cosmetics industry in order to conserve resources. 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 (Patent Document 1).

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

[0004] However, in Patent Document 1, when a sheet-formed inner container with no irregularities in the storage section as shown in Figure 1 is engaged with an outer container to form a double container, if the double container state continues, the outer surface of the inner container and the inner surface of the body of the outer container will come into close contact, making it difficult to remove the inner container when replacing it with a refill.

[0005] In view of the above circumstances, the present invention has an object to provide a double container including an inner container that can be easily removed from an outer container while minimizing the amount of resin used.

[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 wall, and an upper flange that protrudes radially outward from the entire circumference of the upper end of the side wall, the inner container is made of a synthetic resin sheet material, 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 of the outer container, and at least the upper outer periphery of the side wall of the inner container is polygonal.

[0007] According to one aspect, in a double container, the inner container can be easily removed from the outer container while minimizing the amount of resin used.

[0008] 1 is an exploded perspective view of a conventional double container with a cap. 2 is a perspective view of a double container according to a first embodiment of the present invention. 3 is a cross-sectional view of a double container with a cap according to a first embodiment of the present invention. 4 is a cross-sectional view of a double container with a cap according to a first embodiment of the present invention. 5 is an exploded perspective view of a double container with a cap according to the present invention. 6 is a flow chart of a method for manufacturing an inner container according to the present invention. 7 is an explanatory view showing a method for manufacturing an inner container according to the present invention. 8 is an explanatory view showing a method for manufacturing an inner container according to the present invention. 9 is a bottom perspective view of an inner container according to a modified example of the first embodiment of the present invention. 10 is a perspective view of an inner container according to a second embodiment of the present invention. 11 is a perspective view of an inner container according to a third embodiment of the present invention. 12 is a perspective view of an inner container according to a fourth embodiment of the present invention. 13 is a perspective view showing a modified outer container according to 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, the inner container is set in the outer container in advance, or the viscous or solid substance is filled by replacing the entire inner container as a refill (refill container).

[0014] <Overall Configuration of First Embodiment> First, the overall configuration of the double container of the first embodiment of the present invention will be described using Figures 2 to 4. Figure 2 is a perspective view of the double container 3 according to the first embodiment. Figures 3A and 3B are cross-sectional views of the double container 3 according to the first embodiment of the present invention. Figure 4 is an exploded perspective view of the double container 6 with a cap according to the first embodiment.

[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 Fig. 2 has a wide-mouthed, low-profile jar shape. The double container 3 can be engaged with a cap 4.

[0016] In this embodiment, the inner container 1 includes a cylindrical storage section 10 with a bottom surface 11 and a side surface 12, and an upper flange 15 that projects outward from the upper end of the storage section 10. Referring to FIG. 4 , the side surface 12 of the inner container 1 includes a tapered side surface 13 at a lower portion, the diameter of which decreases downward, and an upper polygonal cylindrical side surface 14. While the cylindrical polygon that forms the upper polygonal cylindrical side surface 14 is shown as a regular dodecagon in this example, a polygon having a regular quadrilateral to a regular 24-sided polygon is preferred. The tapered side surface 13, which reduces in diameter at the lower portion of the side surface of the inner container 1, makes it easier to remove a used inner container from the outer container and insert an unused inner container (refill) into the outer container 2.

[0017] 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), acrylic resin (PMMA), or biodegradable resin.

[0018] 3A and 3B, Fig. 3A is a cross-sectional view taken along the line AA' in Fig. 2, and Fig. 3B is a cross-sectional view taken along the line BB' in Fig. 2. That is, Fig. 3A is a cross-sectional view taken along a side of the polygonal cylindrical side surface 14 of the inner container 1, and Fig. 3B is a cross-sectional view taken along a corner of the polygonal cylindrical side surface 14.

[0019] In the polygonal cylindrical side surface 14 at the top of the side surface portion 12 according to this embodiment, in the cross section of the polygon, the line connecting the opposing sides is shorter than the diagonal line connecting the opposing corners.

[0020] Therefore, in the state of the double container 3, as shown in Fig. 3A, 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 24 of the outer container 2. For example, the gap is about 0.2 to 4 mm.

[0021] 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 3B are in contact with the inside surface of the mouth 24 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 24 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 24 are maintained in contact.

[0022] 3B shows an example in which the corners of the polygonal tube side surface 14 are in contact with the inner surface of the mouth 24 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 24 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 24 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 24.

[0023] The outer container 2 is a container housing that replaceably houses the inner container 1. The outer container 2 has a case 20 having a bottom wall 21 and a side wall 22. In the outer container 2, a shoulder 23 extending outward is provided at the upper end of the case 20, and a cylindrical mouth 24 extending upward is provided from the inner edge of the shoulder 23. As shown in Figures 3A and 3B , the cylindrical mouth 24 has a smaller diameter than the side wall 22 of the case 20 and is located more inward than the side wall 22.

[0024] 2 and 4, a screw projection 25 and an annular ridge 26 are provided on the outer peripheral surface of the mouth portion 24 of the outer container 2. The screw projection 25 of the outer container 2 is threadably engaged with the screw projection 43 of the cap 4. The annular ridge 26 is located below the screw projection 25, and the cap 4 engages with the screw projection 25 so as to cover the annular ridge 26. The annular ridge 26 may also serve as a downward finger hook on the outer container 2 side when the inner container 1 is pulled out of the outer container 2.

[0025] 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, PP, PE, ABS, PBT, POM, PET, polyester resin, biodegradable resin, or other resin, 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.

[0026] 4, the cap 4 has a top surface 41 and a peripheral wall 42, and a screw projection 43 is provided on the inside of the peripheral wall 42. In FIG. 4, 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.

[0027] 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 PP, PE, ABS, PBT, POM, PET, or polyester-based resin, biodegradable resin or other resin, glass, wood, silicon, metal, paper, or the like.

[0028] Furthermore, 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).

[0029] When the cap 4 is engaged with the double container 3, the screw projections 25 on the opening 24 of the outer container 2 and the screw projections 43 on the cap 4 are threadably engaged. 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 end flange 15 of the inner container 1.

[0030] 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.

[0031] As shown in the exploded view of Figure 4, 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 and cap 4 are reusable after replacement.

[0032] 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.

[0033] The inner container 1 that can be replaced as a refill can have its top surface covered with a film stretched over the top flange 15 or a cover that surrounds the top flange 15. This allows the refill inner container 1 to be distributed as a single unit.

[0034] 3A and 3B, 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 width of the upper flange 15 of the inner container is the same as or wider than the thickness of the mouth 24 of the outer container.

[0035] Thus, in this embodiment, the upper portion of the side portion (body portion) 12 of the inner container 1 has a polygonal cylindrical side surface 14 with a polygonal outer shape, and therefore, in the upper flange 15 with a circular outer edge, the corners of the polygon are close to the outer edge at a distance di, resulting in a narrower width, while the centers of the polygonal sides are farther from the outer edge at a distance dx, resulting in a wider width. The width di of the upper flange 15 is set according to the thickness of the mouth 24 of the outer container 2, and is, for example, 0.5 mm to 4 mm, while dx is greater than di, being 0.7 mm to 5 mm. Due to this shape, when the double container 3 is in the state where it ...

[0036] When engaging the inner container 1 configured as described 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. Conversely, when replacing the refill, the user can hook the outer edge of the upper flange 15 of the inner container 1 or part of the inner side surface of the side portion 12 of the inner container 1 with their fingers, and pull the inner container 1 upwards relative to the outer container 2.

[0037] <Manufacturing of Inner Container> Next, a manufacturing method for the inner container in the first embodiment will be described with reference to Fig. 5 and Figs. 6A to 6C. Fig. 5 is a flowchart of the manufacturing method for the inner container. Figs. 6A to 6C are explanatory diagrams showing the manufacturing method for the inner container. In Figs. 6A to 6C, Fig. 6A is an explanatory diagram of step S1, Fig. 6B is an explanatory diagram of step S2, and Fig. 6C is an enlarged explanatory diagram of the cut portion in step S3. Note that Figs. 6A and 6B show a schematic diagram of a mold.

[0038] First, in step S1, a thin resin sheet S is heated (FIG. 6A). The thickness of the resin sheet before heating is about 0.3 to 3.0 mm, and heating makes the sheet easier to stretch.

[0039] In step S2, the resin sheet S is brought close to the mold M, and vacuum is created by suction from the bottom of the mold, and air pressure is applied from above the mold to perform pressure molding (FIG. 6B).

[0040] Here, the recess R formed in the mold M is a recess with a polygonal prism-shaped upper portion and a downward-facing truncated cone-shaped lower portion, similar to the storage portion of the inner container 1. Also, in the example shown, the mold M has a substantially annular protrusion P with a polygonal inner edge and a circular outer edge around the recess R, but the protrusion P need not be provided. Here, the amount of depression of the recess R from the outside of the mold M is larger than the amount of protrusion of the protrusion P from the outside, and is about 5 to 20 times larger.

[0041] Furthermore, the mold M is formed with a plurality of thin holes H for vacuuming. Of the vacuum holes H, the vacuum hole H1 on the lower side of the mold M is in communication with the recessed portion R, and the vacuum hole H2 on the outer side is not in communication with the recessed portion R. Note that although Figures 6A and 6B show a configuration in which the vacuum holes H1 and H2 are in communication within the mold M, the vacuum holes H1 and H2 may not be in communication with each other and may extend independently to the lower end of the mold M. Note that although the vacuum hole H2 is shown as being straight in Figures 6A and 6B, the vacuum hole H2 extends while bending outward at its upper end, as shown in more detail in Figure 6C.

[0042] A thin resin sheet S is brought close to a mold M and suction is applied from below the mold M, stretching the resin sheet S along the recessed portion R of the mold M to form the storage portion 10. At this time, a vacuum hole H2 is formed on the outside of the recessed portion R of the mold M, forming an upper flange 15. Because the storage portion 10 along the recessed portion R deforms more than the upper flange 15 along the protruding portion P, the bottom surface 11 and side surface 12 that make up the storage portion 10 are thinner than the upper flange 15. For example, if the thickness of the thin sheet S before molding is 1, the thickness of the storage portion 10 is approximately 0.05 to 0.9, and the thickness of the upper flange is approximately 0.5 to 0.95. In other words, the thickness of the storage portion 10 is approximately 1 / 10 to 19 / 20 of the thickness of the upper flange 15.

[0043] In step S3, the outer edge of the formed container is punched out and cut (separation step). More specifically, as shown in Fig. 6C, the outer edge of the upper flange 15 is cut to form the upper flange.

[0044] In step S4, the molded inner container 1 is released from the mold (demolded).

[0045] 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.

[0046] 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 is softer and more flexible than conventional injection-molded containers due to its thinness. 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.

[0047] Furthermore, in this embodiment, since the upper part of the storage section of the inner container is polygonal, even if it is the exact size as the outer container, the body of the inner container does not adhere closely to the inner surface of the storage section of the outer container, and since the cross-sectional polygonal shape makes the side parts easily bend, it can be easily removed from the outer container.

[0048] 7 is a bottom perspective view of an inner container 1A according to a modification of the first embodiment of the present invention. In this modification, an outer peripheral ring 16, which is a short annular ring, is provided on the outside of the upper end flange 15 of the inner container 1A.

[0049] When manufacturing the inner container 1A of this configuration, in the cutting process of step S3, a portion (outside 16 in Figure 6C) of the outer edge of the convex portion P of the mold M is cut slightly (0.3 to 1 mm) outward in a circular shape when viewed from above, and the folded-over outer ring 16 is also separated from the rest of the sheet together with the upper end flange 15 and the storage section 10.

[0050] In this configuration, in the upper flange 15 having a circular outer edge, the polygonal corners of the inner edge are close to the outer edge at the distance di, resulting in a narrow flange width, while the centers of the sides of the polygonal inner edge are far from the outer edge at the distance dx, resulting in a wide flange width. Furthermore, when the inner container 1A is engaged with the outer container 2 to form a double-container, the outer peripheral ring 16 is located outside the mouth 24, so that the distances di and dx are both equal to or greater than the thickness of the mouth 24.

[0051] Second Embodiment FIG. 8 is a perspective view of an inner container 1α according to a second embodiment of the present invention.

[0052] In this embodiment, the side surface portion 12α of the inner container 1α has a lower tapered side surface 13α whose diameter decreases downward, and an upper wavy side surface 14α. The wavy side surface has a polygonal shape with rounded corners and recessed centers on each side, resembling a so-called African flower. The polygon that forms the wavy shape is preferably a regular 4- to 24-sided polygon.

[0053] In this embodiment, too, in a double-walled container in which the inner container 1α and the outer container 2 are engaged, the upper flange 15α of the inner container 1α is located above the upper end of the mouth 24 of the outer container 2, and therefore the width of the upper flange 15α of the inner container 1α is the same as or wider than the thickness of the mouth 24 of the outer container 2. More specifically, in this embodiment, the upper part of the body of the inner container is wavy and cylindrical, and therefore, as shown in Figure 8, in the upper flange 15α with an annular outer diameter, the rounded corners of the polygon have a small distance diα from the outer edge, resulting in a narrow width, while the recessed parts of the polygon have a large distance dxα from the outer edge, resulting in a wide width. For example, the width of diα is set according to the thickness of the mouth 24 of the outer container 2, and is, for example, 0.5 to 3 mm, and dxα is larger than diα, i.e., 0.7 to 5 mm. Due to this shape, when the container is in a double container state, the inner edges of the rounded corners are in contact with the mouth 24 of the outer container 2 or there is a gap of about 0 to 2 mm, and the recessed parts have a gap of about 0.2 mm to 4 mm.

[0054] In this embodiment, the inner container 1α is also formed from a thin resin sheet, as shown in Figures 5 and 6A to 6C. Because the inner container 1α is formed by sheet molding, its thinness and softness prevent it from fitting too tightly or too loosely, which can easily cause it to come off due to variations in glass manufacturing, and it can easily adapt to variations in molding.

[0055] Furthermore, in this embodiment, the upper part of the side of the inner container 1α is a wavy side surface 14α, so even if the outer container is the perfect size, the body of the inner container does not adhere flatly to the inside surface of the storage section of the outer container, and since the cross section is a wavy polygonal shape, the side surface is prone to bending, so it can be easily removed from the outer container when replacing the refill.

[0056] 9 is a perspective view of an inner container 1β according to a third embodiment of the present invention. In this embodiment, a side surface portion 12β of the inner container 1β has a tapered side surface 13β at the bottom that decreases in diameter toward the bottom, and a cylindrical side surface 14β at the top.

[0057] The outer peripheral surface of the cylindrical side surface 14β is provided with a plurality of vertically extending vertical ribs 17. The vertical ribs 17 are positioned inside the opening 24 when the outer container 2 is engaged with the outer container 2.

[0058] In this embodiment, too, in a double-walled container in which the inner and outer containers are engaged, the upper flange 15β of the inner container is positioned above the upper end of the mouth 24 of the outer container 2, so the width of the upper flange 15β of the inner container 1β is the same size as or wider than the thickness of the mouth 24 of the outer container 2. Specifically, in this embodiment, the upper portion of the body of the inner container is a normal cylindrical shape, so as shown in FIG. 9 , the upper flange 15β has a circular ring shape on both the outer and inner edges. Therefore, the width of the upper flange 15β is set according to the thickness of the mouth 24 of the outer container 2, but is, for example, uniformly about 0.5 to 4 mm. Furthermore, because a vertical rib 17 is provided on the upper portion of the side surface 12β, in the double-walled container state, the outer surface of the cylindrical side surface 14β does not contact the inner surface of the mouth 24 of the outer container 2, but the vertical rib 17 does contact the inner surface of the mouth 24.

[0059] Also in this embodiment, the inner container 1β is molded from a thin resin sheet as shown in the above-mentioned Figures 5 and 6A to 6C. Therefore, even if the outer container is molded from glass, which is prone to manufacturing variations, it can easily adapt to the manufacturing variations of the glass and fit together.

[0060] Furthermore, in this embodiment, multiple vertical ribs are provided on the upper part of the side of the inner container 1β, facing the mouth of the outer container, so that even if the size is a perfect fit, the body of the inner container does not adhere closely to the inside surface of the storage section of the outer container, and the vertical ribs form convex parts that protrude outward when the storage section is cross-sectioned, making the side section prone to bending, so that the inner container can be easily removed from the outer container when replacing the refill.

[0061] Fourth Embodiment FIG. 10 is a perspective view of an inner container 1γ according to a fourth embodiment of the present invention.

[0062] In this embodiment, the side surface portion 12γ of the inner container 1γ has a lower, tapered side surface 13γ whose diameter decreases downward, and an upper, cylindrical side surface 14γ.

[0063] The cylindrical side surface 14γ is provided on its outer peripheral surface with a circumferentially extending annular rib 18. When the outer container 2 is engaged with the annular rib 18, the annular rib 18 is positioned inside the opening.

[0064] In this embodiment, too, in a double container in which the inner and outer containers are engaged, the upper flange of the inner container is located above the upper end of the mouth of the outer container, and therefore the upper flange of the inner container is the same size as or wider than the thickness of the mouth 24 of the outer container. More specifically, in this embodiment, as in the third embodiment, the upper flange has an annular shape, and the width of the upper flange 15γ is set according to the thickness of the mouth 24 of the outer container 2, but is, for example, approximately 0.5 to 4 mm. Furthermore, because an annular rib is provided at the top of the side surface, in the double container state, the outer surface of the cylindrical side surface 14γ does not contact the inner surface of the mouth 24 of the outer container 2, and the annular rib 18 does contact the inner surface of the mouth 24.

[0065] In this embodiment, the inner container 1γ is also molded from a thin resin sheet, as shown in Figures 5 and 6A to 6C above. Therefore, even if the outer container is molded from glass, which is prone to manufacturing variations, it can easily adapt to manufacturing variations in the glass and fit together.

[0066] 10 shows an example in which the annular rib 18 is provided over the entire circumferential area, but the annular rib may be provided intermittently in the circumferential direction. Alternatively, a plurality of ribs extending in the circumferential direction may be provided in the vertical direction.

[0067] (Modification of Outer Container) In FIG. 2, the thickness of the mouth of the outer container is uniform, but the mouth may have a thin-walled portion in which part of the outer periphery is thin.

[0068] Referring to Figure 11, in this configuration, the mouth 24δ of the outer container 2δ has thick-walled mouth portions 27A, 27B and thin-walled mouth portions 28A, 28B. The mouth 24δ has a continuous circumferential inner surface and an outer surface with a stepped thickness change from the circumferential surface, with multiple alternating thick-walled mouth portions 27A, 27B and thin-walled mouth portions 28A, 28B. Specifically, the thin-walled mouth portions 28A, 28B are vertically elongated rectangular regions of the mouth 24δ that are partially recessed on the outside, extending from the upper end of the mouth 24δ but not reaching the lower end. Therefore, the portions below the annular ridges 26 of the thin-walled mouth portions 28A, 28B in the mouth 24δ have the same thickness as the thick-walled mouth portions 27A, 27B.

[0069] When the above-described inner container 1 is applied to the outer container of this configuration, the upper flange 15 of the inner container 1 is also located above the upper end of the mouth 24 of the outer container 2. The width of the upper flange 15 is the same as or wider than the thickness of the mouth thick-walled portions 27A, 27B of the mouth 24δ of the outer container 2δ.

[0070] In this configuration, when replacing the refill, the inner container 1 is separated from the outer container 2δ by placing fingers on the thin-walled mouth portions 28A, 28B of the outer container 2δ and pushing the inner container 1 and the upper end flange 15 upward or pulling the upper end flange 15 upward.

[0071] In the example of Figure 11, two thin-walled mouth portions 28 are provided at the mouth 24δ of the outer container 2δ, but the number of thin-walled mouth portions may be one or three or more.

[0072] 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.

[0073] This application claims priority based on Japanese Patent Application No. 2023-219987, filed on December 26, 2023, the entire contents of which are incorporated herein by reference.

[0074] DESCRIPTION OF SYMBOLS 1, 1A, 1α, 1β, 1γ Inner container 10, 10α, 10β, 10γ Storage section 11 Bottom surface 12, 12α, 12β, 12γ Side surface 13, 13α, 13β, 13γ Diameter-reducing side surface 14 Polygonal cylindrical side surface 14α Wavy side surface 14β, 14γ Cylindrical side surface 15 Upper end flange 17 Vertical rib 18 Annular rib 2, 2δ Outer container 20 Case section 21 Bottom wall 22 Side wall 23 Shoulder section 24 Mouth section (cylindrical mouth section) 25 Screw projection 26 Annular ridge 27A, 27B Mouth section thick-walled section (thick-walled section) 28A, 28B Mouth section thin-walled section (thin-walled section) 3 Double container 4 Cap 5 Gasket (sealing material) 6 Double container with cap M 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, and an upper end flange that protrudes radially outward from the entire circumference of the upper end portion of the side surface portion, the inner container is composed of a sheet material made of synthetic resin, in a state of the double container in which 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 portion of the outer container, and at least the outer circumference of the upper portion of the side surface portion of the inner container is polygonal. The double container.

2. 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, and an upper end flange that protrudes radially outward from the entire circumference of the upper end portion of the side surface portion, the inner container is composed of a sheet material made of synthetic resin, in a state of the double container in which 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 portion of the outer container, and the outer circumference of the side surface portion of the inner container is wavy. The double container.

3. 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 and having a smaller diameter than the side wall, the inner container has a bottom surface, a side surface portion, and an upper end flange that protrudes radially outward from the entire circumference of the upper end portion of the side surface portion, the inner container is composed of a sheet material made of synthetic resin, a plurality of vertical ribs are provided on the outer circumference of the side surface portion of the inner container, in a state of the double container in which 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 portion of the outer container, and the plurality of vertical ribs of the inner container are located inside the mouth portion of the outer container. The double container.

4. A double container having an outer container and an inner container that is removably accommodated as a refill with respect to the outer container, wherein the outer container has a bottom wall, a side wall, and a cylindrical mouth portion located above the side wall and having a smaller diameter than the side wall, the inner container has a bottom surface, a side surface portion, and an upper end flange that protrudes radially outward from the entire circumference of the upper end portion of the side surface portion, the inner container is composed of a synthetic resin sheet material, an annular rib is provided on the outer circumference of the side surface portion, in a state of the double container in which 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 portion of the outer container, and the annular rib of the inner container is located inside the mouth portion of the outer container.

5. The double container according to any one of claims 1 to 4, wherein the outer container is formed of glass.

6. A refill container that is removably accommodated with respect to an outer container having a cylindrical mouth portion, wherein the refill container includes a bottom surface, a side surface portion, and an upper end flange that protrudes radially outward from the entire circumference of the upper end portion of the side surface portion, the refill container is composed of a synthetic resin sheet material, and at least the outer circumference of the upper portion of the side surface portion is polygonal.

7. A refill container that is removably accommodated with respect to an outer container having a peripheral wall with a cylindrical inner peripheral surface, wherein the refill container includes a bottom surface, a side surface portion, and an upper end flange that protrudes radially outward from the entire circumference of the upper end portion of the side surface portion, the refill container is composed of a synthetic resin sheet material, and at least the outer circumference of the upper portion of the side surface portion is wavy.

8. A refill container that is removably accommodated with respect to an outer container having a peripheral wall with a cylindrical inner peripheral surface, wherein the refill container includes a bottom surface, a side surface portion, and an upper end flange that protrudes radially outward from the entire circumference of the upper end portion of the side surface portion, the refill container is composed of a synthetic resin sheet material, and a plurality of vertical ribs are provided on at least the upper portion of the outer peripheral surface of the side surface portion.

9. A refill container that is removably accommodated in an outer container having a peripheral wall with a cylindrical inner peripheral surface, the refill container comprising a bottom surface, a side surface portion, and an upper end flange that projects radially outward from the entire circumference of the upper end of the side surface portion, the refill container being made of a synthetic resin sheet material, and an annular rib being provided at least on an upper portion of the outer peripheral surface of the side surface portion.

10. The refill container according to any one of claims 6 to 9, wherein the side surface portion has a reduced-diameter side surface that tapers downward in the vicinity of the bottom surface.

11. A method for manufacturing a refill container that is removably accommodated in an outer container, the method comprising: heating a thin sheet material made of synthetic resin; bringing the sheet material close to a mold having a depression communicating with a vacuum suction hole and performing vacuum / pressure molding to mold the sheet material into a container shape; and separating the outside of the container by punching. In the mold, the inner wall surface constituting the depression is polygonal or wavy in top view, and the molded container has a receiving portion with a polygonal or wavy side surface that is recessed with respect to the outside. In the separating step, while forming an upper end flange at a predetermined interval outward from the upper end of the side surface of the receiving portion, the container is separated in a circular shape in top view.

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