Double container

Abstract

To provide a dual container which allows an inner bag to be easily pulled out from an outer shell.SOLUTION: There is provided a dual container having a container body and a mouth part attachment member, in which the container body comprises a mouth part, a trunk part, and a bottom part. The mouth part is a cylindrical portion having an opening end. The trunk part is disposed adjacent to the mouth part on a side away from the opening end of the mouth part, and has a larger outside diameter than that of the mouth part. The bottom part is configured to close a bottom edge of the trunk part. The container body comprises an inner bag, and an outer shell disposed to cover the inner bag. The mouth part attachment member is configured to be attachable to the mouth part, and is configured so that the inner bag rotates with rotation of the mouth part attachment member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention discloses a dual container. [Background technology]

[0002] Conventionally, double containers having a container body with an outer shell and an inner bag have been known. For example, Patent Document 1 discloses that an outer shell preform and an inner bag preform are stacked together and biaxially stretched blow molded to form a double container (so-called delaminating container) configured so that the inner bag shrinks as the contents decrease. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-10741 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the outer shell and inner bag of such a double container are made of different materials, or when contents remain inside the inner bag after use, it is desirable to separate the outer shell and inner bag when recycling the double container.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a double-layered container in which the inner bag can be easily pulled out from the outer shell. [Means for solving the problem]

[0006] According to the present invention, there is provided a double container including a container body and a mouth-attaching member. The container body includes a mouth portion, a body portion, and a bottom portion. The mouth portion is a cylindrical portion having an open end. The body portion is disposed adjacent to the mouth portion on a side farther from the open end than the mouth portion and has an outer diameter larger than that of the mouth portion. The bottom portion is configured to close the lower end of the body portion. The container body includes an inner bag and an outer shell disposed to cover the inner bag. The mouth-attaching member is configured to be attachable to the mouth portion and to rotate the inner bag as the mouth-attaching member rotates.

[0007] In the double container of the present invention, since the inner bag is configured to rotate as the mouth-attaching member rotates, it is possible to twist the inner bag by rotating the mouth-attaching member. Since the outer diameter of the body portion of the container body is larger than that of the mouth portion, it is not easy to pull out the inner bag through the mouth portion simply by pulling the inner bag. However, by twisting the inner bag to reduce the diameter of the body portion, the body portion of the inner bag can easily pass through the mouth portion of the outer shell, and the inner bag can be easily pulled out from the outer shell.

[0008] Hereinafter, various embodiments of the present invention will be exemplified. The embodiments shown below can be combined with each other. Preferably, in the double container described above, the inner bag includes a protruding portion protruding from the open end of the outer shell. The protruding portion includes a protruding cylinder and an engaging protrusion protruding radially outward from the circumferential surface of the protruding cylinder. The engaging protrusion is configured to rotate the inner bag as the mouth-attaching member rotates by engaging with a claw portion of the mouth-attaching member in the rotational direction of the mouth-attaching member. Preferably, in the double container described above, the protruding portion includes an engaging flange at a position farther from the open end than the engaging protrusion. The engaging flange is configured to pull out the inner bag from the outer shell as the mouth-attaching member moves in a direction away from the open end by engaging with a claw portion of the mouth-attaching member in the axial direction of the mouth portion. Preferably, the double container described above, wherein the protruding portion includes a contact flange that contacts the opening end, and the engaging protrusion is disposed between the contact flange and the engaging flange, is a double container. Preferably, the double container described above, wherein at least one of the inner surfaces of the mouth portion and the position adjacent to the mouth portion of the body portion has an uneven shape in which concave and convex ridges appear alternately in the circumferential direction of the mouth portion, and the concave and convex ridges extend non-parallel to the circumferential direction of the mouth portion, is a double container. Preferably, a double container including a container body, wherein the container body includes a mouth portion, a body portion, and a bottom portion, the mouth portion is a cylindrical portion having an open end, the body portion is disposed adjacent to the mouth portion on the side farther from the open end than the mouth portion and has a larger outer diameter than the mouth portion, the bottom portion is configured to close the lower end of the body portion, the container body includes an inner bag and an outer shell disposed to cover the inner bag, and at least one of the mouth portion and the position adjacent to the mouth portion of the body portion has an uneven shape in which concave and convex ridges appear alternately in the circumferential direction of the mouth portion, and the concave and convex ridges extend non-parallel to the circumferential direction of the mouth portion, is a double container.

Brief Description of the Drawings

[0009] [Figure 1] It is a front view of a double container 1 according to an embodiment of the present invention, showing a state where the mouth mounting member 8 is separated from the container body 2. The dashed-dotted line in the figure represents the boundary line where the curvature of the surface forming the surface shape changes. The same applies to other figures. [Figure 2] Figure 2A is a cross-sectional view taken along line A-A in Figure 1, and Figure 2B is a cross-sectional view taken along line B-B in Figure 2A. [Figure 3] It is an enlarged perspective view of the vicinity of the mouth portion 5 in Figure 1. [Figure 4] Figure 4A is a perspective view with a part of the mouth mounting member 8 cut away, and Figure 4B is a perspective view of the mouth mounting member 8 viewed from the lower oblique side. [Figure 5] Figure 5A is a front view of a state where the mouth mounting member 8 is mounted on the container body 2, and Figure 5B is a cross-sectional view taken along line B-B in Figure 5A. [Figure 6] It is a perspective view showing a state in which the inner preform 14 and the outer preform 13 are separated. [Figure 7] FIG. 7A is a front view of the inner preform 14, FIGS. 7B and 7C are cross-sectional views taken along line B-B and line C-C in FIG. 7A, respectively, and FIG. 7D is a perspective view of the inner preform 14 seen obliquely from above. [Figure 8] It is a perspective view of the preform 15 formed by covering the inner preform 14 with the outer preform 13.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described. Various characteristic matters shown in the embodiments shown below can be combined with each other. Also, an invention can be established independently for each characteristic.

[0011] 1. Double container 1 As shown in FIG. 1, the double container 1 according to an embodiment of the present invention includes a container body 2 and a mouthpiece mounting member 8.

[0012] As shown in FIG. 1, the container body 2 includes a mouth portion 5, a body portion 6, and a bottom portion 7. The mouth portion 5 is a cylindrical (preferably circular cylindrical) portion having an open end 5c. The mouth portion 5 includes an engaging portion 5a to which a mouthpiece mounting member 8 such as a cap or a pump can be mounted. When the mouthpiece mounting member 8 is screw-type, the engaging portion 5a is a male screw portion, and when the mouthpiece mounting member 8 is a stopper type, it is an annular protrusion protruding in the circumferential direction. The mouthpiece mounting member 8 preferably has a check valve (not shown), and although the discharge of the content is possible, outside air does not flow into the container body 2. A flange 5b is provided on the mouth portion 5. The flange 5b can be used to support the mouth portion 5 when the mouthpiece mounting member 8 is mounted on the mouth portion 5.

[0013] The body portion 6 is disposed adjacent to the mouth portion 5 on the side away from the opening end 5c of the mouth portion 5. The body portion 6 has a larger outer diameter than the mouth portion 5 (in this specification, the "outer diameter" means the circumscribed circle diameter when the cross-section is not circular). The body portion 6 is cylindrical, and the bottom portion 7 is provided at the lower end of the body portion 6 and closes the lower end of the body portion 6. The body portion 6 includes a shoulder portion 6b whose outer diameter increases as it moves away from the mouth portion 5, and a body portion main body 6c provided on the bottom portion 7 side of the shoulder portion 6b and having a substantially constant outer diameter.

[0014] The diameter of the mouth portion 5 excluding the engaging portion 5a is, for example, 20 to 40 mm, preferably 25 to 35 mm, specifically, for example, 20, 25, 30, 35, 40 mm, and may be within the range between any two of the values exemplified here. The length of the mouth portion 5 is, for example, 15 to 35 mm, specifically, for example, 15, 20, 25, 30, 35 mm, and may be within the range between any two of the values exemplified here.

[0015] As shown in FIG. 2, the container body 2 includes an inner bag 4 and an outer shell 3 disposed so as to cover the inner bag 4. In the inner bag 4, portions other than the protruding portion 4c described later are accommodated inside the outer shell 3. In the following description, the portions of the inner bag 4 corresponding to the mouth portion 5, the body portion 6, and the bottom portion 7 of the container body 2 are respectively referred to as the mouth portion 5, the body portion 6, and the bottom portion 7 of the inner bag 4. The same applies to the outer shell 3.

[0016] When a check valve is provided in the mouth portion mounting member 8, the inner bag 4 contracts as the content of the inner bag 4 is discharged. When a check valve is not provided in the mouth portion mounting member 8, the inner bag 4 does not contract even after the content of the inner bag 4 is discharged, so it is not easy to pull out the inner bag 4 through the mouth portion 5 of the outer shell 3. Since the present invention facilitates pulling out the inner bag 4 through the mouth portion 5 of the outer shell by twisting and reducing the diameter of the inner bag 4, when a check valve is not provided in the mouth portion mounting member 8, the significance of applying the present invention is particularly remarkable. However, even when a check valve is provided in the mouth portion mounting member 8, the inner bag 4 may not appropriately reduce its diameter when contracting, so even when a check valve is provided in the mouth portion mounting member 8, the significance of applying the present invention is remarkable.

[0017] An outside air introduction hole 16 is provided in the body portion 6 or the bottom portion 7. The outside air introduction hole 16 is a through hole penetrating the outer shell 3, and outside air can be introduced into the intermediate space between the outer shell 3 and the inner bag 4 through the outside air introduction hole 16. When the double container 1 is a so-called squeeze-type container configured to discharge the contents by compressing the outer shell 3, it is preferable to provide a check valve for controlling the inflow and outflow of air through the outside air introduction hole 16. The check valve is preferably configured to close the outside air introduction hole 16 when the outer shell 3 is compressed and to open the outside air introduction hole 16 when the compression force is removed. In this case, when a compression force is applied to the outer shell 3, the compression force is likely to be applied to the inner bag 4, and after the contents are discharged, outside air is quickly introduced into the intermediate space, and the shape of the outer shell 3 is quickly restored.

[0018] When a check valve is provided in the outside air introduction hole 16, the outside air introduction hole 16 is preferably disposed in a recess 6d provided in the body portion 6. In this case, it is possible to avoid the check valve interfering with the shrink film when the body portion 6 is covered with the shrink film. Further, it is preferable to provide a groove 6e extending from the recess 6d toward the mouth portion 5. The groove 6e extends to a position not covered with the shrink film. Thereby, it is possible to avoid the recess 6d being sealed with the shrink film.

[0019] As shown in Fig. 2, on at least one of the inner surfaces of the mouth part 5 and the position adjacent to the mouth part 5 in the body part 6, an uneven shape 9 is provided in which concave stripes 9a and convex stripes 9b appear alternately in the circumferential direction of the mouth part 5. The uneven shape 9 is provided on the inner surface of the inner bag 4. The number of the concave stripes 9a is, for example, 4 to 30, and preferably 10 to 20. The concave stripes 9a and the convex stripes 9b preferably extend non-parallel to each other in the circumferential direction of the mouth part 5. The direction in which the concave stripes 9a and the convex stripes 9b extend is preferably 0 to 60 degrees, and more preferably 0 to 30 degrees, with respect to the axial direction of the mouth part 5. Specifically, this angle is, for example, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 degrees, and may be within the range between any two of the numerical values exemplified here. The uneven shape 9 may be provided only on the mouth part 5, or may be provided at a position adjacent to the mouth part 5 in the body part 6, but is preferably provided across the mouth part 5 and the body part 6. The uneven shape 9 may be formed by reducing the wall thickness of the concave stripe 9a compared to other parts of the mouth part 5 of the inner bag 4, or by increasing the wall thickness of the convex stripe 9b, or by reducing the wall thickness of the concave stripe 9a and increasing the wall thickness of the convex stripe 9b.

[0020] Since the wall thickness of the convex stripe 9b is larger than that of the concave stripe 9a, when the twist applied to the mouth part 5 is transmitted to the body part 6, the convex stripe 9b transmits force more easily than the concave stripe 9a. As a result, the convex stripe 9b rotates faster than the concave stripe 9a, and as a result, a crease is formed in the inner bag 4 on the concave stripe 9a and its extension line, so that the inner bag 4 can be easily folded in a pleated shape. Therefore, by providing the uneven shape 9, the body part 6 is folded in a pleated shape, and as a result, the diameter of the body part 6 is quickly reduced. It should be noted that it is preferable not to provide an uneven shape on the outer surface of the inner bag 4. This is because if an uneven shape is provided on the outer surface of the inner bag 4, the inner bag 4 and the outer shell 3 engage with each other in the rotation direction of the inner bag 4, making it difficult for the inner bag 4 to rotate relative to the outer shell 3.

[0021] If the thickness of the inner bag 4 at the ridges 9b of the mouth 5 (the radius of the circumscribing circle of the inner bag 4 minus the radius of the inscribed circle passing through the apexes of the ridges 9b) is T and the depth of the recesses 9a (the radius of the inscribed circle passing through the bottoms of the recesses 9a minus the radius of the inscribed circle passing through the apexes of the ridges 9b) is D, the maximum value of D / T is, for example, 0.2 to 0.8, and preferably 0.3 to 0.5. Specific examples of this value are 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.8, and may be within a range between any two of the values exemplified here. The thickness of the inner bag 4 at the mouth 5 other than the concave-convex shape 9 is, for example, 1 to 2 mm, specifically, for example, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 mm, and may be within a range between any two of the numerical values exemplified here. The depth of the recessed stripes 9a at the portion where the depth is greatest is, for example, 0.3 to 1.0 mm, specifically, for example, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 mm, and may be within a range between any two of the numerical values exemplified here.

[0022] The distance from the opening edge 5c of the mouth portion 5 to the upper end of the uneven shape 9 is, for example, 0 to 30 mm, specifically, for example, 0, 5, 10, 15, 20, 25, or 30 mm, and may be within a range between any two of the numerical values exemplified here. The distance from the upper end to the lower end of the uneven shape 9 is, for example, 10 to 40 mm, specifically, for example, 10, 15, 20, 25, 30, 35, or 40 mm, and may be within a range between any two of the numerical values exemplified here.

[0023] The mouth attachment member 8 is configured to be attachable to the mouth 5, and is configured so that the inner bag 4 rotates as the mouth attachment member 8 rotates (here, relative rotation with respect to the outer shell 3). With this configuration, it is possible to twist the inner bag 4 by rotating the mouth attachment member 8. Because the body 6 of the container body 2 has a larger outer diameter than the mouth 5, it is not easy to pull the inner bag 4 through the mouth 5 of the outer shell 3 simply by pulling the inner bag 4. However, by twisting the inner bag 4 and reducing the diameter of the body 6 of the inner bag 4, the body 6 of the inner bag 4 can more easily pass through the mouth 5 of the outer shell 3, and the inner bag 4 can be easily pulled out of the outer shell 3.

[0024] The engagement structure between the mouth-attached member 8 and the inner bag 4 will now be described in more detail.

[0025] 2 and 3, the inner bag 4 has a protruding portion 4c that protrudes from the open end 3a of the outer shell 3. The protruding portion 4c has a protruding tube 4c1, an engaging protrusion 4c2, an engaging flange 4c3, and an abutting flange 4c4.

[0026] The engaging protrusion 4c2 protrudes radially outward from the circumferential surface of the protruding tube 4c1. The engaging flange 4c3 is an annular portion located farther from the open end 3a than the engaging protrusion 4c2 and having a larger diameter than the protruding tube 4c1. The abutting flange 4c4 is an annular portion located at a position abutting the open end 3a and having a larger diameter than the protruding tube 4c1. The abutting flange 4c4 abuts against the open end 3a, thereby preventing the inner bag 4 from falling into the outer shell 3. Alternatively, the abutting flange 4c4 may be omitted and the engaging protrusion 4c2 may be abutted against the open end 3a to prevent the inner bag 4 from falling into the outer shell 3.

[0027] As shown in FIGS. 3 to 5, the mouth attachment member 8 includes an outer tube 8a, an intermediate tube 8b, an inner tube 8c, an engagement portion 8d, a claw portion 8e, a top plate 8f, and a nozzle 8g.

[0028] An engagement portion 8d is provided on the inner surface of the outer cylinder 8a. The engagement portion 8d is an engagement portion that engages with the engagement portion 5a of the mouth portion 5, and the mouth-mounted member 8 is attached to the mouth portion 5 by engaging the engagement portion 8d with the engagement portion 5a.

[0029] The intermediate cylinder 8b has a smaller diameter than the outer cylinder 8a and is disposed above the outer cylinder 8a. The inner cylinder 8c has a smaller diameter than the intermediate cylinder 8b and is a so-called inner ring that is disposed inside the outer cylinder 8a and the intermediate cylinder 8b. The upper surface of the intermediate cylinder 8b is covered with a top plate 8f. A nozzle 8g is provided on the top plate 8f.

[0030] Claws 8e are provided on the inner surface of the intermediate cylinder 8b. A plurality of claws 8e (eight in this embodiment) are provided and spaced apart in the circumferential direction. The number of claws 8e is, for example, 1 to 20, and preferably 4 to 12. Each claw 8e has an upper surface 8e1 and a lower inclined surface 8e2. A through hole 8h is provided in the top plate 8f at a position facing the claw 8e.

[0031] The mouth attachment member 8 having such a shape can be manufactured using a split mold that opens and closes in the vertical direction. Because the through-hole 8h and the upper surface 8e1 can be formed using the protrusions on the upper mold, the claws 8e can be formed without forcibly removing the lower mold. Therefore, it is not necessary to set the protrusion amount of the claws 8e to an amount that allows for forcible removal, and the protrusion amount can be set to an amount suitable for engagement with the inner bag 4 (e.g., 1 mm or more).

[0032] In this embodiment, since the engaging portion 5a is a male screw portion and the engaging portion 8d is a female screw portion, the mouthpiece mounting member 8 can be mounted on the mouthpiece 5 by relatively rotating the mouthpiece mounting member 8 with respect to the mouthpiece 5 in the tightening direction (usually the clockwise direction when viewed from above). (Hereinafter, the relative rotation with respect to the mouthpiece 5 is also simply referred to as "rotation".) When the mouthpiece mounting member 8 is rotated in the tightening direction, while the engaging portion 8d is screwed onto the engaging portion 5a, the claw portion 8e gradually approaches the protruding portion 4c, and at a certain point, the lower inclined surface 8e2 abuts against the engaging flange 4c3. In this state, when the mouthpiece mounting member 8 is further rotated in the tightening direction, the claw portion 8e overrides the engaging flange 4c3 and reaches the state shown in FIG. 5. In this state, the claw portion 8e is disposed between the engaging flange 4c3 and the abutting flange 4c4. The engaging flange 4c3 is accommodated in the gap between the claw portion 8e and the top plate 8f. As shown in FIG. 5B, the protruding cylinder 4c1 is disposed between the claw portion 8e and the inner cylinder 8c. At this point, if the screws of the engaging portion 5a and the engaging portion 8d are not fully tightened, the claw portion 8e is guided by the circumferential inclined surface 4c5 provided on the engaging protrusion 4c2 and overrides the engaging protrusion 4c2, so that the mouthpiece mounting member 8 can be further rotated in the tightening direction. After the screws of the engaging portion 5a and the engaging portion 8d are fully tightened, the mouthpiece mounting member 8 cannot be rotated in the tightening direction and cannot move in the axial direction of the mouthpiece 5.

[0033] In this state, the engaging protrusion 4c2 is engaged with the claw portion 8e of the mouthpiece mounting member 8 in the rotational direction of the mouthpiece mounting member 8, and the engaging flange 4c3 is engaged with the claw portion 8e of the mouthpiece mounting member 8 in the axial direction of the mouthpiece 5. That is, the claw portion 8e is engaged with the engaging protrusion 4c2 and the engaging flange 4c3.

[0034] Therefore, after the contents in the inner bag 4 are used up, when the mouthpiece mounting member 8 is rotated in the loosening direction (usually the counterclockwise direction when viewed from above), the inner bag 4 rotates as the mouthpiece mounting member 8 rotates. As a result, the inner bag 4 is twisted and its diameter is reduced.

[0035] When the mouthpiece mounting member 8 is further rotated in the loosening direction and the screwing engagement between the engaging portion 8d and the engaging portion 5a is released, the mouthpiece mounting member 8 becomes movable in the direction away from the open end 3a (i.e., the axial direction of the mouthpiece 5). Since the engaging flange 4c3 is engaged with the mouthpiece mounting member 8 in the axial direction of the mouthpiece 5, when the mouthpiece mounting member 8 is moved in the axial direction of the mouthpiece 5, the inner bag 4 also moves together with the mouthpiece mounting member 8, and the inner bag 4 is pulled out from the outer shell 3.

[0036] As described above, according to the configuration of the present embodiment, by simply rotating the mouthpiece mounting member 8 in the loosening direction, after the inner bag 4 is twisted and its diameter is reduced, it is pulled out from the outer shell 3, so that the inner bag 4 and the outer shell 3 can be smoothly separated with a simple operation.

[0037] 2. Manufacturing method of the double container 1 As shown in FIGS. 6 to 8, the container body 2 can be formed by heating a preform 15 formed by covering an inner preform 14 that becomes the inner bag 4 with an outer preform 13 that becomes the outer shell 3 and performing biaxial stretch blow molding.

[0038] As shown in FIG. 6, the inner preform 14 has a bottomed cylindrical shape and includes a mouth portion 14a, a body portion 14b, and a bottom portion 14c. A protruding portion 14d is provided at the open end of the mouth portion 14a. The protruding portion 14d remains in its original shape without being deformed during molding and becomes the protruding portion 4c. Therefore, the matters described for the protruding portion 4c also apply to the protruding portion 14d. The bottom portion 14c is provided so as to close the lower end of the body portion 14b. A positioning pin 14c1 is provided on the bottom portion 14c.

[0039] As shown in FIG. 7, an uneven shape 19 is provided on the inner surface of the inner preform 14. The uneven shape 19 remains in its original shape or is stretched during molding to become the uneven shape 9 of the container body 2. The description regarding the uneven shape 9 also applies to the uneven shape 19 as long as it does not contradict the gist thereof.

[0040] As shown in FIG. 6, the outer preform 13 is a bottomed cylindrical shape and includes a mouth portion 13a, a body portion 13b, and a bottom portion 13c. The bottom portion 13c is provided so as to close the lower end of the body portion 13b. A positioning hole (not shown) is provided in the bottom portion 13c.

[0041] As shown in FIG. 8, when forming the preform 15, the protruding portion 14d is brought into contact with the opening end of the mouth portion 13a, and the positioning pin 14c1 is inserted into the positioning hole. Thereby, the inner preform 14 and the outer preform 13 are positioned relative to each other. In this state, the mouth portion 14a and the mouth portion 13a face each other, and the body portion 14b and the body portion 13b face each other.

[0042] The mouth portions 13a and 14a become the mouth portion 15a of the preform 15, the body portions 13b and 14b become the body portion 15b of the preform 15, and the bottom portions 13c and 14c become the bottom portion 15c of the preform 15. The body portion 15b and the bottom portion 15c are mainly stretched in the biaxial stretch blow molding.

[0043] The inner preform 14 and the outer preform 13 can be formed by direct blow molding or injection molding of a thermoplastic resin such as polyester (e.g., PET) or polyolefin (e.g., polypropylene, polyethylene). The inner preform is preferably made of a material having a larger molding shrinkage rate than the outer preform. In this case, a gap is formed between the outer shell 3 and the inner bag 4 due to molding shrinkage, facilitating the introduction of outside air into the intermediate space between the outer shell 3 and the inner bag 4.

[0044] In one example, the inner preform 14 is made of polyolefin (e.g., polypropylene), and the outer preform 13 is made of PET. Since polyolefin has a larger molding shrinkage rate than PET, such a resin configuration makes it easier to form a gap between the outer shell 3 and the inner bag 4. Also, by making the materials of the inner preform 14 and the outer preform 13 different, welding between them during blow molding is suppressed.

[0045] The inner preform 14 is preferably formed by direct blow molding. According to direct blow molding (blow molding using a molten tubular parison), the inner preform 14 having a laminated structure can be easily formed. The outer preform 13 is preferably formed by injection molding.

[0046] After the preform 15 is subjected to biaxial stretch blow molding, the container body 2 shown in FIG. 1 can be obtained by forming an outside air introduction hole 16 in the outer shell 3. Then, after filling the inner bag 4 with the content, the double container 1 can be obtained by attaching the mouthpiece attachment member 8 to the mouthpiece 5.

[0047] 3. Other Embodiments · In the above embodiment, the outside air introduction hole 16 is formed after biaxial stretch blow molding, but a through hole serving as the outside air introduction hole may be formed in the outer preform 13 in advance. · The outside air introduction hole 16 may be formed at the bottom of the outer shell 3. · From another perspective, the present invention can be understood as an invention that aims to provide a double container 1 including an inner bag 4 that is easily reduced in diameter by twisting. From this perspective, the configuration for twisting the inner bag 4 is not particularly limited, so it does not have to be configured such that the inner bag 4 rotates as the mouthpiece attachment member 8 rotates. In this case, for example, the inner bag 4 may be pinched with a finger and rotated. Therefore, as the mouthpiece attachment member 8, a cap or a pump having no structure for engaging with the inner bag 4 may be used. Further, the container body 2 does not have to include the protruding portion 4c. For example, instead of the protruding portion 4c, a flange may be provided at the open end of the inner bag 4, and by bringing this flange into contact with the open end of the outer shell 3, it is possible to prevent the inner bag 4 from falling off into the outer shell 3.

Explanation of Reference Numerals

[0048] 1: Double container 2: Container body 3: Outer shell 3a: Open end 4: Inner bag 4c: Protruding portion 4c1: Protruding cylinder 4c2: Engagement projection 4c3: Engagement flange 4c4: Contact flange 4c5: Circumferential inclined surface 5: Mouth part 5a: Engagement part 5b: Flange 5c: Open end 6: Barrel part 6b: Shoulder 6c: Barrel body 6d: Recess 6e: Groove 7: Bottom part 8: Mouth part mounting member 8a: Outer cylinder 8b: Intermediate cylinder 8c: Inner cylinder 8d: Engagement part 8e: Claw part 8e1: Upper surface 8e2: Lower inclined surface 8f: Top plate 8g: Nozzle 8h: Through hole 9: Concavo-convex shape 9a: Concave stripe 9b: Convex stripe 13: Outer preform 13a: Mouth part 13b: Barrel part 13c: Bottom part 14: Inner preform 14a: Mouth part 14b: Barrel part 14c: Bottom part 14c1: Positioning pin 14d: Protrusion 15: Preform 15a: Mouth part 15b: Barrel part 15c: Bottom part 16: Outer air introduction hole 19: Concavo-convex shape

Claims

1. A double container comprising a container body and a mouthpiece mounting member, wherein: The container body includes a mouth portion, a body portion, and a bottom portion. The mouth portion is a cylindrical portion having an open end. The body portion is disposed adjacent to the mouth portion on a side farther from the open end than the mouth portion, and has an outer diameter larger than that of the mouth portion. The bottom portion is configured to close the lower end of the body portion. The container body includes an inner bag and an outer shell disposed so as to cover the inner bag. The mouthpiece mounting member is configured to be attachable to the mouth portion, and the inner bag is configured to rotate as the mouthpiece mounting member rotates. The double container is configured to twist the inner bag as the mouthpiece mounting member rotates to reduce the diameter of the body portion.

2. The double container according to Claim 1, wherein: The inner bag includes a protruding portion that protrudes from the open end of the outer shell. The protruding portion includes a protruding cylinder and an engaging protrusion that protrudes radially outward from the circumferential surface of the protruding cylinder. The double container is configured such that the inner bag rotates as the mouthpiece mounting member rotates by the engaging protrusion engaging with a claw portion of the mouthpiece mounting member in the rotation direction of the mouthpiece mounting member.

3. A double container comprising a container body and a mouthpiece mounting member, wherein: The container body includes a mouth portion, a body portion, and a bottom portion. The mouth portion is a cylindrical portion having an open end. The body portion is disposed adjacent to the mouth portion on a side farther from the open end than the mouth portion, and has an outer diameter larger than that of the mouth portion. The bottom portion is configured to close the lower end of the body portion. The container body includes an inner bag and an outer shell disposed so as to cover the inner bag. The mouthpiece mounting member is configured to be attachable to the mouth portion, and the inner bag is configured to rotate as the mouthpiece mounting member rotates. The inner bag includes a protruding portion that protrudes from the open end of the outer shell. The protruding portion includes a protruding cylinder and an engaging protrusion that protrudes radially outward from the circumferential surface of the protruding cylinder. The double container is configured such that the inner bag rotates as the mouthpiece mounting member rotates by the engaging protrusion engaging with a claw portion of the mouthpiece mounting member in the rotation direction of the mouthpiece mounting member. The claw portion engages with the engaging protrusion by abutting against the engaging protrusion along the rotation direction of the mouthpiece mounting member.

4. A double container comprising a container body and a mouthpiece mounting member, wherein: The container body includes a mouth portion, a body portion, and a bottom portion. The mouth part is a cylindrical part having an open end, The body part is arranged adjacent to the mouth part on the side farther from the open end than the mouth part, and has a larger outer diameter than the mouth part. The bottom part is configured to close the lower end of the body part. The container body includes an inner bag and an outer shell arranged to cover the inner bag. The mouth part mounting member is configured to be mountable on the mouth part, and the inner bag is configured to rotate as the mouth part mounting member rotates. The inner bag includes a protruding part protruding from the open end of the outer shell. The protruding part includes a protruding cylinder and an engaging protrusion protruding radially outward from the circumferential surface of the protruding cylinder. The engaging protrusion is configured such that the inner bag rotates as the mouth part mounting member rotates by engaging with a claw part of the mouth part mounting member in the rotation direction of the mouth part mounting member. The protruding part includes an engaging flange at a position farther from the open end than the engaging protrusion. The double container in which the engaging flange engages with a claw part of the mouth part mounting member in the axial direction of the mouth part, and the inner bag is pulled out of the outer shell as the mouth part mounting member moves in a direction away from the open end.

5. The double container according to claim 4, The protruding part includes a contact flange that contacts the open end. The engaging protrusion is arranged between the contact flange and the engaging flange. The double container.

6. The double container according to any one of claims 1 to 5, On at least one of the inner surfaces of the mouth part and the position adjacent to the mouth part of the body part, an uneven shape in which concave stripes and convex stripes appear alternately in the circumferential direction of the mouth part is provided. The concave stripes and the convex stripes extend non-parallel to each other in the circumferential direction of the mouth part. The double container.

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