Container, method for producing same, and double container

Abstract

Provided is a container in which it is possible to introduce a rotation-restricting structure while increasing the degree of freedom of selection of a mouth part attachment member.　According to the present invention, a container comprises a container body, and a mouth part attachment member attached to a mouth part of the container body, wherein: the mouth part attachment member is configured to be attached to the mouth part in a plugging manner; the container body is provided with an axial engagement part that engages with the mouth part attachment member in the axial direction, and a circumferential engagement part that engages with the mouth part attachment member in the circumferential direction; the axial direction is the direction in which the central axis of the opening extends, and the circumferential direction is the rotational direction centered on the central axis; the circumferential direction engagement part is disposed at a position farther away from the opening end of the mouth part than the axial direction engagement part; the mouth part attachment member is provided with an engagement part; and the engagement part of the mouth part attachment member engages with the axial direction engagement part in the axial direction and engages with the circumferential direction engagement part in the circumferential direction. The container according to the present invention is exceptional in recyclability and can be suitably used for producing a recycled material.

Description

Container and manufacturing method thereof, double container

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

[0002] (First Aspect) Patent Document 1 discloses a configuration in which a discharge tool is engaged with a portion of an inner layer of a double container that protrudes from an outer layer.

[0003] (Second aspect) Patent document 2 discloses a double container that is configured such that a mouth attachment member that is circumferentially engaged with the inner bag is rotated relative to the outer shell, thereby rotating the inner bag relative to the outer shell, thereby twisting the inner bag to reduce its diameter, and then the mouth attachment member is pulled so that the inner bag can be pulled out of the container body.

[0004] (Third and Fourth Aspects) Conventionally, double-layered containers including a container body having an outer shell and an inner bag have been known. For example, Patent Document 3 discloses a double-layered container formed by biaxially stretch blow molding an outer shell preform and an inner bag preform in a stacked state.

[0005] JP 2023-67209 A JP 2024-018821 A JP 2019-10741 A

[0006] (First Aspect) In Patent Document 1, rotation of the dispenser in the circumferential direction is restricted by engaging an anti-rotation rib provided on the dispenser with a vertical rib provided on the inner layer in the circumferential direction.

[0007] Such a rotation restriction structure is premised on the use of a discharge tool with a specific structure, and cannot be used with a commonly available discharge tool.

[0008] The present invention has been made in view of the above circumstances, and aims to provide a container that allows for the introduction of a rotation restriction structure while increasing the degree of freedom in the selection of a spout attachment member.

[0009] (Second Aspect) In the double-walled container of Patent Document 2, the spout attachment member is attached to the inner bag using a stopper-type fastening mechanism, and even when the spout attachment member is rotated relative to the inner bag, it does not come off the inner bag. On the other hand, some commercially available spout attachment members are screw-type. When such spout attachment members are attached to the inner bag, applying torque to the spout attachment member to rotate the inner bag relative to the outer shell may result in relative rotation between the spout attachment member and the inner bag, rather than relative rotation between the inner bag and the outer shell. For this reason, screw-type spout attachment members cannot currently be used. Furthermore, even with a stopper-type spout attachment member, if the spout attachment member and the inner bag are not circumferentially engaged, rotating the spout attachment member relative to the outer shell may prevent the inner bag from rotating relative to the outer shell. These circumstances limit the freedom of choice when selecting spout attachment members.

[0010] The present invention was made in consideration of these circumstances, and provides a double container that allows the inner bag to be twisted to reduce its diameter while increasing the freedom of selection of the mouth attachment member.

[0011] (Third aspect) However, when the outer shell and inner bag of such a double container are formed from 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.

[0012] The outer shell and the inner bag can be separated by the user by pulling the inner bag from the outer shell, and it is desirable to reduce the force required to pull out the inner bag. It is also desirable to have excellent dischargeability of the contents from the double container.

[0013] The present invention has been made in consideration of the above circumstances, and provides a double container that can reduce the force required to pull out the inner bag and has excellent discharge properties for the contents.

[0014] (Fourth aspect) However, when the outer shell and inner bag of such a double container are formed from 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.

[0015] It is assumed that the outer shell and inner bag will be separated by pulling the inner bag out of the container body, and in order to simplify the process of pulling the inner bag out of the container body as much as possible, one possible method is to engage the cap with the inner bag in the axial direction and then pull the cap to pull out the inner bag.

[0016] However, to prevent the contents of the inner bag from leaking, a cap is attached to seal the opening of the inner bag, and if you try to pull out the inner bag with the cap attached, the air inside the inner bag will not escape, causing the inner bag to not shrink and making it difficult to pull out the inner bag.

[0017] The present invention has been made in view of the above circumstances, and aims to provide a double container in which the inner bag can be easily pulled out from the container body.

[0018] (First Aspect) According to the present invention, the following inventions are provided. [1] A container comprising a container body and a spout mounting member attached to a spout of the container body, wherein the spout mounting member is configured to be attached to the spout in a stoppered manner, and the container body comprises an axial engaging portion that engages with the spout mounting member in an axial direction and a circumferential engaging portion that engages with the spout mounting member in a circumferential direction, the axial direction being the direction in which a central axis of the spout extends, the circumferential direction being the direction of rotation about the central axis, the circumferential engaging portion being positioned farther from the open end of the spout than the axial engaging portion, and the spout mounting member comprising an engaging portion, the engaging portion of the spout mounting member engaging with the axial engaging portion in the axial direction and engaging with the circumferential engaging portion in the circumferential direction. [2] The container according to [1], wherein the circumferential engaging portion comprises a plurality of engaging protrusions arranged at intervals along the circumferential direction. [3] The container according to [1] or [2], wherein the axial engaging portion comprises an annular convex portion. [4] The container according to any one of [1] to [3], wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the inner bag comprises a protrusion protruding from an open end of the outer shell, and the axial engaging portion and the circumferential engaging portion are provided on the protrusion. [5] The container according to any one of [1] to [4], wherein the spout attachment member comprises an outer tube, and the engaging portion is provided on the inner circumferential surface of the outer tube.

[0019] (Second Aspect) The present invention provides the following inventions. [1] A double container comprising a container body, an engaging member, and a spout attachment member, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the inner bag having a protrusion protruding from the open end of the outer shell, the spout attachment member attached to the protrusion, and the engaging member and the protrusion engaged circumferentially at a circumferential engagement portion. [2] The double container according to [1], wherein the container body is configured such that, when viewed from above the double container, rotating the inner bag in one direction relative to the outer shell displaces the inner bag in a direction that causes it to slip out of the container body. [3] The double container according to [2], wherein the spout attachment member and the protrusion are screwed together such that rotation of the spout attachment member in the one direction relative to the protrusion is a loosening direction of the screw engagement. [4] The double container according to any one of [1] to [3], wherein the engaging member and the protruding portion are engaged in a concave-convex manner in the circumferential direction at the circumferential engaging portion. [5] The double container according to any one of [1] to [4], wherein the protruding portion has a male thread portion, the inner bag has a flange, the lower surface of the flange abuts against the outer shell, and the circumferential engaging portion is disposed between the male thread portion and the flange. [6] The double container according to any one of [1] to [5], wherein the protruding portion is disposed in an opening provided in the engaging member. [7] The double container according to [6], wherein the engaging member has a cylindrical portion and a top surface portion provided on a top surface of the cylindrical portion, the opening is provided on the top surface portion, and the peripheral surface of the opening and the outer peripheral surface of the protruding portion are engaged in the circumferential direction. [8] A double container as described in [7], wherein the protrusion is provided with a male thread portion, the inner bag is provided with a flange, the lower surface of the flange abuts against the outer shell, the circumferential engaging portion is arranged between the male thread portion and the flange, the upper surface of the flange abuts against the top surface portion, and the tubular portion of the engaging member is arranged to surround the outer shell.

[0020] (Third Aspect) According to the present invention, the following inventions are provided: [1] A double container comprising a container body, the container body comprising an inner bag and an outer shell arranged to cover the inner bag, the inner bag configured to be removable from the container body, the container body comprising a mouth, a body, and a bottom, the mouth being a tubular portion having an open end, the body being arranged adjacent to the mouth on a side farther from the open end than the mouth, the bottom being configured to close the lower end of the body, the direction in which the central axis of the mouth of the container body extends is defined as an axial direction, the overall height of the container body is defined as H, and a shoulder portion configured such that the circumferential length in a cross section perpendicular to the axial direction increases with increasing distance from the mouth portion, where Hmax / H is 0.20 to 0.40; and where DLmax is the outer diameter in the major axis direction at which the outer diameter is greatest in the maximum circumferential portion and DSmax is the outer diameter in the minor axis direction perpendicular to the major axis direction, DSmax / DLmax is 0.70 to 0.95. [2] The double-walled container according to [1], wherein the portion of the body portion where the circumferential length in a cross section perpendicular to the axial direction is the smallest is defined as a minimum circumferential portion, and where the height of the minimum circumferential portion from the bottom surface of the container body is Hmin and the outer diameter in the major axis direction at the minimum circumferential portion is DLmin, the ratio (DLmax-DLmin) / (Hmin-Hmax) is 0.26 to 0.46. [3] The double-walled container according to [2], wherein Hmin / H is 0.80 to 0.90. [4] The double container according to any one of [1] to [3], wherein the body portion has an inwardly convex curved portion that is convex inward and an outwardly convex curved portion that is convex outward, the outwardly convex curved portion is located closer to the bottom surface than the inwardly convex curved portion, the maximum perimeter portion is located on the outwardly convex curved portion, and where Hb is the height from the bottom surface of the boundary portion between the inwardly convex curved portion and the outwardly convex curved portion and DLb is the outer diameter in the major axis direction at the boundary portion, (DLmax - DLb) / (Hb - Hmax) is 0.28 to 0.48. [5] The double container according to [4], wherein Hb / H is 0.45 to 0.75.

[0021] (Fourth Aspect) The present invention provides the following: [1] A double container comprising a container body and a spout attachment member attached to the spout of the container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, and wherein, when the direction in which the central axis of the spout of the container body extends is taken as the axial direction, the spout attachment member comprises a main body member and an open / close member, the main body member engages with the inner bag in the axial direction and has a discharge port communicating with the interior of the inner bag, the open / close member is configured to be able to open and close the discharge port, and the open / close member is provided with an easy-to-open portion having a structure that makes it easy to form an opening that communicates with the interior of the inner bag. [2] The double container according to [1], wherein the open / close member comprises an outer cylinder that forms the outer peripheral surface of the open / close member, and the main body member has an exposed portion that is not covered by the lower end of the outer cylinder and is exposed to the outside. [3] The double container according to [1] or [2], wherein the easily opening forming portion comprises a weakened portion provided on the opening / closing member and a protrusion provided adjacent to the weakened portion, a cavity provided below the protrusion, and the easily opening forming portion is configured to be able to form the opening by tearing the weakened portion and connecting the cavity to the outside when the protrusion is tilted. [4] The double container according to [1] or [2], wherein the easily opening forming portion comprises a weakened portion provided on the opening / closing member and a protrusion provided adjacent to the weakened portion, a cavity provided below the protrusion, and the easily opening forming portion is configured to be able to form the opening by tearing the weakened portion when the protrusion is pushed into the cavity. [5] A double container as described in [1] or [2], wherein the easy-to-open portion comprises a pressing portion provided on the opening / closing member, a cavity is provided below the pressing portion, the pressing portion is composed of a weakened portion or is provided adjacent to the weakened portion, and the easy-to-open portion is configured so that the opening can be formed by pressing the tip of an opening tool against the pressing portion and forcing the opening tool into the cavity, thereby tearing the weakened portion.[6] A double container as described in [1] or [2], wherein the easy-to-open forming portion comprises a lid portion provided on the opening / closing member, the lid portion is connected to the peripheral wall of a cavity provided on the underside of the lid portion at a connecting portion, and the easy-to-open forming portion is configured to be able to tear the connecting portion by gripping and pulling up a gripping portion provided on the lid portion, thereby exposing the cavity and forming the opening. [7] A double container comprising a container body and a mouth attachment member attached to the mouth of the container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, and when the direction in which the central axis of the mouth of the container body extends is taken as the axial direction, the mouth attachment member comprises a main body member and an opening / closing member, the main body member engages with the inner bag in the axial direction and has a discharge port communicating with the inside of the inner bag, the opening / closing member is configured to be able to open and close the discharge port, and the opening / closing member has an outer tube that forms the outer peripheral surface of the opening / closing member, and the main body member has an exposed portion that is not covered by the lower end of the outer tube and is exposed to the outside.

[0022] (First Aspect) In the container of the present invention, the circumferential engaging portion is located farther from the open end of the mouth than the axial engaging portion, and the engaging portion provided on the mouth attachment member is configured to engage with the circumferential engaging portion and the axial engaging portion. In this configuration, a rotation restricting structure is configured by the engaging portion of the mouth attachment member engaging with the circumferential engaging portion. Since the engaging portion of the mouth attachment member is a portion that is present on substantially all stopper-type mouth attachment members, according to the present invention, it is possible to introduce a rotation restricting structure while increasing the freedom of selection of the mouth attachment member.

[0023] (Second aspect) In the double container of the present invention, the engaging member is circumferentially engaged with the protruding portion of the inner bag, so that by gripping the engaging member and rotating it relative to the outer shell, the inner bag is rotated relative to the outer shell, thereby twisting the inner bag to reduce its diameter. Therefore, in the double container of the present invention, there is no need to apply torque to the spout attachment member when twisting the inner bag, so there is no need for the spout attachment member and the inner bag to be circumferentially engaged, and the freedom of selection of the spout attachment member is increased.

[0024] (Third Aspect) In the double-walled container of the present invention, the maximum circumferential portion, where the circumferential length is greatest, is located at a low position on the container body, allowing the body of the container body to gradually expand in diameter from the opening of the container body toward the maximum circumferential portion. If the body of the container body rapidly expands in diameter, friction between the inner bag and the outer shell increases when the inner bag is pulled out, and the force required to pull out the inner bag increases. However, by gradually expanding the body of the container body toward the maximum circumferential portion, the force required to pull out the inner bag can be reduced. Furthermore, since the container body of the double-walled container of the present invention has a flattened shape at the maximum circumferential portion, it is easy to crush the container body and dispense the contents. Therefore, according to the present invention, the force required to pull out the inner bag can be reduced and a double-walled container with excellent content dispensability can be obtained.

[0025] (Fourth Aspect) In the double container of the present invention, the opening / closing member provided on the spout attachment member is provided with an easy-to-open portion having a structure that makes it easy to form an opening that communicates with the inside of the inner bag. Therefore, it is easy to form an opening in the opening / closing member, and after the opening is formed, air inside the inner bag escapes through the opening when the inner bag is pulled out, making it easy to pull the inner bag out of the container body.

[0026] (First View) A perspective view of a container 11 according to a first embodiment of the present invention. The dashed-dotted lines in the figure represent boundaries where the curvature of the surfaces constituting the surface shape changes. This also applies to other figures. An exploded perspective view of the container 11 of FIG. 1. FIG. 3A is a longitudinal cross-sectional view of the container 11 of FIG. 1 with the opening / closing member 42 closed. FIG. 3B is an enlarged view of region B in FIG. 3A. FIG. 3A is an exploded view of FIG. 3A with the opening / closing member 42 slightly open. FIG. 4 is a division view of the container body 2 of FIG. 4. FIG. 6A is an exploded perspective view of the vicinity of the mouth 5 of FIG. 2, and FIG. 6B is a front view of the inner bag 4. FIG. 7A is a perspective view of the main body member 41 of the mouth attachment member 8 of FIG. 2, viewed from a different angle. FIG. 7B is a cross-sectional perspective view of the main body member 41 of FIG. 7A cut in half. A perspective view showing the inner preform 14 and the outer preform 13 separated. FIG. 9A is a perspective view of a preform 15 formed by covering an outer preform 13 on an inner preform 14, and FIG. 9B is a front view of the preform 15. FIG. 10A is a view of the side of the inner preform 14 from a direction along the parting line PL, FIG. 10B is an end view taken along line B-B in FIG. 10A, and FIGS. 10C to 10F are enlarged views of areas C to F in FIG. 10B. (Second Perspective) A perspective view of a double container 1 according to an embodiment of the present invention. An exploded perspective view of the double container 1 of FIG. 11. An exploded perspective view of the vicinity of the mouth 5 of the container body 2 in FIG. 12. A cross-sectional view of the double container 1 of FIG. 11. However, only a portion of the pump 9 is shown in cross-section, with the remainder shown in front view. This is an exploded view of the cross-sectional view of FIG. 14. However, only a portion of the pump 9 is shown. FIG. 16A is a perspective view of the engaging member 45 seen obliquely from below. FIG. 16B is a bottom view of the engaging member 45. Fig. 16C is an end view taken along line CC in Fig. 14. Fig. 16C is an enlarged view of the vicinity of the mouth 5 in a state in which the pump 9 has been removed from the double container 1 in Fig. 11 and the top surface 45e of the engaging member 45 has been removed. Fig. 16B is a perspective view showing a state in which the inner preform 14 and the outer preform 13 have been separated. Fig. 16C is a perspective view of a double container 1 according to an embodiment of the present invention, in which the inner preform 14 is covered with the outer preform 13. ...23A and Fig. 23B are a right side view and a bottom view, respectively, of the container body 2 in Fig. 20.24A to 24C are cross-sectional views taken along lines A-A, B-B, and C-C in FIG. 22, respectively. (Fourth Viewpoint) A perspective view of the double container 1 according to the first embodiment of the present invention. The dashed-dotted lines in the figures represent the boundary lines where the curvature of the surfaces constituting the surface shape changes. This also applies to the other figures. An exploded perspective view of the double container 1 in FIG. 25. FIG. 27A is a longitudinal cross-sectional view of the double container 1 in FIG. 25 with the opening / closing member 42 closed. FIG. 27B is an enlarged view of region B in FIG. 27A. An exploded view of FIG. 27A. FIG. 29A is a perspective view of the opening / closing member 42 of the spout-mounted member 8 in FIG. 26, viewed from a different angle. FIG. 29B is an enlarged view of region B in FIG. 29A. FIG. 30A is a cross-sectional perspective view of the opening / closing member 42 in FIG. 29A, and FIG. 30B is an enlarged view of region B in FIG. 30A. FIG. 31A is a cross-sectional view of the opening / closing member 42 with the protrusion 8f folded down to form the opening 51. Fig. 31B is an enlarged view of region B in Fig. 31A. Fig. 32A is a perspective view of open-close member 42 according to a second embodiment of the present invention, and Fig. 32B is an enlarged view of region B in Fig. 32A. Fig. 33A is a cross-sectional view of open-close member 42 in Fig. 32A, and Fig. 33B is a cross-sectional view after protrusion 8f is pushed into cavity 53 from the state of Fig. 33A to form opening 51. Fig. 34A is a perspective view of open-close member 42 according to a third embodiment of the present invention, and Fig. 34B is an enlarged view of region B in Fig. 34A. Fig. 35A is a cross-sectional view of open-close member 42 in Fig. 34A, and Fig. 35B is a cross-sectional view after tip 54a of opening tool 54 is pushed into cavity 53 from the state of Fig. 35A to form opening 51. FIG. 36A is a cross-sectional view of a modified example of the opening / closing member 42 of FIG. 34A, and FIG. 36B is a cross-sectional view after the tip 54a of the opening tool 54 is pushed into the cavity 53 from the state of FIG. 36A to form the opening 51. FIG. 37A is a perspective view of the opening / closing member 42 of a fourth embodiment of the present invention, and FIG. 37B is a front view of the opening / closing member 42 of FIG. 37A. FIG. 38A is a cross-sectional view of the opening / closing member 42 of FIG. 37A with the lid portion 8j partially removed, and FIG. 38B is an enlarged view of the lid portion 8j and base 8m in FIG. 38A. FIG. 39A is a cross-sectional view taken along line A-A in FIG. 37B, and FIG. 39B is an enlarged view of the base 8m in FIG. 39A. FIG. 40A is a perspective view of the cross-section taken along line B-B in FIG. 37B, and FIG. 40B is an enlarged view of region B in FIG. 40A.FIG. 41A is a cross-sectional view taken along line A-A in FIG. 39A , and FIG. 41B is a cross-sectional view showing the state after the lid portion 8j has been pulled up from the state shown in FIG. 41A to form the opening 51. FIG. 42A is a perspective view of the mouth attachment member 8 according to a fifth embodiment of the present invention, and FIG. 42B is a cross-sectional view of the mouth attachment member 8 shown in FIG. 42A . FIG. 43A is a perspective view of an opening / closing member 42 according to a sixth embodiment of the present invention, and FIG. 43B is a perspective view of the opening / closing member 42 shown in FIG. 43A from a different angle. FIG. 44A is a perspective view of the mouth attachment member 8 having the opening / closing member 42 shown in FIG. 43A , and FIG. 44B is a cross-sectional view of the mouth attachment member 8 shown in FIG. 44A . FIG. 45A is a perspective view of the opening / closing member 42 according to a seventh embodiment of the present invention, and FIG. 45B is a perspective view of the opening / closing member 42 shown in FIG. 45A from a different angle. 46A is a perspective view of the mouth attachment member 8 having the opening and closing member 42 of FIG. 45A, and FIG. 46B is a cross-sectional view of the mouth attachment member 8 of FIG. 46A.

[0027] Hereinafter, embodiments of the present invention will be described. Various features shown in the following embodiments can be combined with each other. Each feature can be an invention independently. In the following embodiments, elements not specified in the claims are optional elements and can be omitted. Any number of "0"s (for example, one or two) may be added to the end of numerical values ​​disclosed in the following description. For example, one or two "0"s may be added after "1.4" to make it "1.40" or "1.400".

[0028] (First Viewpoint) 1. First Embodiment A container 11 according to a first embodiment of the present invention will be described using Figures 1 to 10. In the following description, terms relating to directions, such as "upper" and "lower," refer to directions when the bottom 7 is in contact with the ground. Furthermore, in the following description, the "axial direction" refers to the direction in which the central axis C (shown in Figure 2) of the mouth 5 extends, e.g., the direction in which the inner bag 4 is pulled out from the container body 2. The "circumferential direction" refers to the direction of rotation about the central axis C of the mouth 5, e.g., the direction in which the inner bag 4 is rotated relative to the outer shell 3 at the mouth 5. Unless otherwise specified, "clockwise" and "counterclockwise" refer to directions as viewed from the top of the container 11.

[0029] 1-1. Configuration of Container 11 As shown in Fig. 1, the container 11 of the first embodiment of the present invention comprises a container body 2 and a spout attachment member 8. In this embodiment, the container 11 is a double-walled container 1, and the container body 2 comprises an inner bag 4 and an outer shell 3, but the rotation restriction structure of this embodiment can also be applied to cases where the container 11 is a single-walled container. Each component will be described in detail below.

[0030] 2 and 3, the container body 2 includes a mouth 5, a body 6, and a bottom 7. The mouth 5 is a tubular (preferably cylindrical) portion having an open end 5c. The open end 5c is the open end of the container body 2 and also the open end of the inner bag 4.

[0031] The body 6 is disposed adjacent to the mouth 5 on a side farther from the open end 5c than the mouth 5. The body 6 has a larger outer diameter (in this specification, "outer diameter" means the circular equivalent diameter when the cross section is not circular) than the mouth 5. The body 6 is cylindrical, and the bottom 7 is provided at the lower end of the body 6 and closes the lower end of the body 6. The body 6 has a shoulder 6b whose outer diameter increases with increasing distance from the mouth 5. The body 6 also has a body main body 6c on the bottom 7 side of the shoulder 6b. The body main body 6c has a shape in which the outer diameter is approximately constant toward the bottom 7, or a shape in which the diameter decreases toward the bottom 7, for example.

[0032] 3 to 6, the container body 2 includes an inner bag 4 and an outer shell 3 disposed to cover the inner bag 4. The inner bag 4 has an inner bag body 4d other than the protruding portion 4c housed within the outer shell 3. In the following description, the portions of the inner bag 4 that correspond to the mouth 5, body 6, and bottom 7 of the container body 2 will be referred to as the mouth 5, body 6, and bottom 7 of the inner bag 4, respectively. The same applies to the outer shell 3.

[0033] <Engagement Structure Between Container Body 2 and Mouth Attachment Member 8> The mouth attachment member 8 is a member attached to the mouth 5 of the container body 2. In this embodiment, the mouth attachment member 8 is a cap 8a, but it may also be another member such as a pump. The mouth attachment member 8 is configured to be attached to the mouth 5 in a stoppering manner. As shown in FIG. 6 , the container body 2 has an axial engagement portion 4ma that engages with the mouth attachment member 8 in the axial direction, and a circumferential engagement portion 4mb that engages with the mouth attachment member 8 in the circumferential direction. The circumferential engagement portion 4mb is positioned farther from the open end 5c of the mouth 5 than the axial engagement portion 4ma. It is preferable that the container body 2 and the mouth attachment member 8 do not engage with each other at any location other than the axial engagement portion 4ma and the circumferential engagement portion 4mb.

[0034] The spout attachment member 8 includes an engaging portion 8b. The engaging portion 8b is preferably provided on the inner circumferential surface of the outer tube 41a of the spout attachment member 8. The engaging portion 8b is preferably an annular protrusion 8b3. The engaging portion 8b axially engages with the axial engaging portion 4ma and circumferentially engages with the circumferential engaging portion 4mb. The circumferential engagement between the circumferential engaging portion 4mb and the engaging portion 8b may be a concave-convex engagement or a frictional engagement. Since the engaging portion 8b is provided on substantially all capping-type spout attachment members 8, the configuration of the present invention makes it possible to realize a rotation-restricting structure between the spout attachment member 8 and the container body 2 using a capping-type spout attachment member 8 of substantially any configuration, greatly increasing the freedom of selection of the spout attachment member 8. Capping-type spout attachment members having dimensions and shapes conforming to the F-port standard are widely available and are highly available.

[0035] 6, the axial engaging portion 4ma preferably includes an annular protrusion 4c5, and the circumferential engaging portion 4mb preferably includes a plurality of engaging protrusions 4c2 spaced apart along the circumferential direction. The annular protrusion 4c5 has a tapered surface 4c8 on its upper surface. This makes it easier for the engaging portion 8b to climb over the annular protrusion 4c5 when attaching the mouth-mounting member 8.

[0036] When the engaging portion 8b overcomes the axial engaging portion 4ma and engages with it, the state shown in FIG. 3B is reached. In this state, the tip 8b4 of the engaging portion 8b is pressed against the circumferential engaging portion 4mb, and the engaging portion 8b and the circumferential engaging portion 4mb are frictionally engaged. Furthermore, for example, if the circumferential engaging portion 4mb is composed of multiple engaging protrusions 4c2, each of the engaging protrusions 4c2 has a tapered shape, and the engaging portion 8b is more easily deformed than the engaging protrusions 4c2, when the engaging portion 8b is pressed against the engaging protrusions 4c2, the engaging protrusions 4c2 will sink into the engaging portion 8b, and the engaging portion 8b and the engaging protrusions 4c2 will engage with each other in the circumferential direction. For example, if the engaging portion 8b is made of a polyethylene-based resin and the engaging protrusions 4c2 are made of a polypropylene-based resin, the engaging protrusions 4c2 will easily sink into the engaging portion 8b because polypropylene-based resins are typically more rigid than polyethylene-based resins.

[0037] <Detailed Structure of Outer Shell 3 and Inner Bag 4> As shown in Fig. 4, the inner bag 4 has a protrusion 4c that protrudes from the open end 3a of the outer shell 3. As shown in Figs. 5 and 6, the inner bag 4 has a first tube 4a and a second tube 4b. The first tube 4a is disposed within the outer shell 3. The second tube 4b has a larger outer diameter than the first tube 4a and is disposed closer to the open end 5c of the inner bag 4 than the first tube 4a. The entire second tube 4b may be disposed outside the outer shell 3, or part or all of the second tube 4b may be disposed within the outer shell 3, with the remainder disposed outside the outer shell 3. The protrusion 4c preferably protrudes along the axial direction.

[0038] As shown in FIG. 5 , the second tube 4b includes a peripheral wall 4b1 and a lower wall 4b2 disposed below the peripheral wall 4b1 and configured to reduce the diameter of the peripheral wall 4b1 toward the first tube 4a. The inner bag 4 is positioned so that the lower wall 4b2 abuts against the outer shell 3. The abutment of the lower wall 4b2 with the outer shell 3 prevents the inner bag 4 from penetrating into the outer shell 3. The peripheral wall 4b1 preferably extends parallel to the axial direction. Furthermore, the angle α of the peripheral wall 4b1 relative to the lower wall 4b2 is preferably 90 degrees or greater (90 degrees in this embodiment). In this case, the bending of the inner bag 4 at the corner 4b3 between the lower wall 4b2 and the peripheral wall 4b1 is relatively gentle, making it less likely to crack when impacted, thereby improving impact resistance. The length L1 between the lower surface 4b4 of the lower wall 4b2 and the lower surface 4m3 of the axial engagement portion 4ma is preferably 2 mm or greater. This further reduces local bending of the inner bag 4. The length L1 is, for example, 2 to 10 mm, preferably 3 to 6 mm (4.5 mm in this embodiment). Specifically, the length L1 may be, for example, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, or 10.0 mm, or may be in a range between any two of the values ​​exemplified here. The peripheral wall 4b1 preferably has a portion parallel to the axial direction. The portion parallel to the axial direction preferably has a length from the lower surface 4b4 within the above-mentioned range. Furthermore, the peripheral wall 4b1 is preferably parallel to the axial direction between the lower surface 4b4 and the lower surface 4m3, and is preferably parallel to the axial direction throughout the entire portion between the lower surface 4b4 and the lower surface 4m3.

[0039] The open end 3a of the outer shell 3 is provided with a base surface 3a1, an annular protrusion 3a2, and an inner bag support surface 3a3. The base surface 3a1 is preferably annular. The annular protrusion 3a2 is disposed inside the base surface 3a1 and protrudes axially from the base surface 3a1. Preferably, as shown in FIGS. 3 and 4 , the base surface 3a1 faces the open end 41a1 of the outer tube 41a of the mouth-attached member 8, and the annular protrusion 3a2 protrudes toward the inside of the outer tube 41a of the mouth-attached member 8. With this configuration, even if the contents of the inner bag 4 enter the gap 44 between the base surface 3a1 and the open end 41a1, the annular protrusion 3a2 prevents the contents from penetrating between the inner bag 4 and the outer shell 3. Furthermore, it is preferable that the apex 3a4 of the annular protrusion 3a2 is higher than the open end 41a1. In this case, the penetration of the contents is further prevented.

[0040] The inner bag support surface 3a3 is the surface against which the lower wall 4b2 abuts. The inner bag support surface 3a3 is preferably annular. When the lower wall 4b2 abuts against the inner bag support surface 3a3, the inner bag 4 is supported by the outer shell 3, preventing the inner bag 4 from penetrating into the outer shell 3. The inner bag support surface 3a3 is disposed inside the base surface 3a1 and the annular protrusion 3a2. The inner bag support surface 3a3 is preferably located lower than the base surface 3a1. In this case, a portion of the peripheral wall 4b1 closer to the lower wall 4b2 is covered by the outer shell 3, and therefore the lower wall 4b2 and corners 4b3 are also covered by the outer shell 3. This protects the corners 4b3, which have relatively low impact resistance, by the outer shell 3, further improving the impact resistance of the inner bag 4.

[0041] As shown in Figures 4 and 6, the inner bag 4 has an axial engagement portion 4ma and a circumferential engagement portion 4mb on a protruding portion 4c that protrudes from the open end 3a of the outer shell 3. As shown in Figures 5 and 6, the axial engagement portion 4ma and the circumferential engagement portion 4mb are provided so as to protrude radially outward from the peripheral wall 4b1. As shown in Figure 5, a recess 4c13 is provided on the inner peripheral surface of the axial engagement portion 4ma. It is preferable that the mouth attachment member 8 does not engage with the outer shell 3.

[0042] As shown in Figure 5, the length L2 in the axial direction between the open end 5c of the inner bag 4 and the underside 4m3 of the axial engagement portion 4ma is preferably 4.0 to 5.0 mm. The F-port standard specifies that the length L2 be 4.5 mm, and by setting the length L2 within this range, a mouth attachment member 8 that complies with the F-port standard can be used. Various mouth attachment members 8 that comply with the F-port standard are commercially available, making them highly available. Specifically, the length L2 may be, for example, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 mm, or may be within a range between any two of the values ​​exemplified here.

[0043] The inner bag 4 includes an inclined portion 4e and a tubular sealing portion 4f, in this order, closer to the opening end 5c than the lower surface 4m3. As shown in Figures 3 and 4, the inner surface of the tubular sealing portion 4f closely contacts the outer surface 41b1 of the inner tube 41b provided in the mouth attachment member 8. This prevents leakage of the contents inside the inner bag 4. The inclined portion 4e is configured to reduce the diameter of the axial engagement portion 4ma toward the tubular sealing portion 4f. As shown in Figure 5, the length L3 between the lower end of the tubular sealing portion 4f and the lower surface 4m3 of the axial engagement portion 4ma in the axial direction is preferably 1.2 to 4.0 mm. Setting the length L3 in this range makes it easier to set the length L2 within the above range. Specifically, the length L3 may be, for example, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, or 4.0 mm, or may be in a range between any two of the values ​​exemplified here.

[0044] An expanded diameter portion 4o is provided at the open end 5c of the inner bag 4, which makes it easier to insert the inner tube 41b into the inner bag 4.

[0045] The axial length L4 between the opening end 5c and the lower end of the tubular seal portion 4f, and the length L5 of the tubular seal portion 4f, are preferably 0.5 to 3.3 mm. By setting the lengths L4 and L5 within these ranges, it becomes easier to set the lengths L2 and L3 within the above ranges. Specifically, the lengths L4 and L5 are, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, and 3.3 mm, respectively, and may be within a range between any two of the values ​​exemplified here.

[0046] The axial engaging portion 4ma preferably has a protruding length L6 from the peripheral wall 4b1 of 0.60 to 1.85 mm. This has the advantage that it is easier to keep L2 to L4 within the above range. Specific examples of the protruding length L6 include 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, and 1.85 mm, and may be in a range between any two of the values ​​exemplified here.

[0047] In order to comply with the F-port standard, it is preferable that at least one of the following dimensions is satisfied: - The outer diameter of the axial engagement portion 4ma is 30.5 to 33.8 mm (preferably 31.8 to 33.3 mm, and more preferably 32.3 to 33.3 mm; in this embodiment, 32.8 mm); - The outer diameter of the open end 5c of the inner bag 4 is 29.0 to 31.0 mm (preferably 29.5 to 30.5 mm; in this embodiment, 30.0 mm); - The diameter of the outer peripheral surface of the cylindrical sealing portion 4f is 28.1 to 30.1 mm (preferably 28.6 to 29.6 mm; in this embodiment, 29.1 mm).

[0048] 6, a ridge 4g is provided on the outer peripheral surface of the inner bag 4 (more specifically, the inner bag main body 4d). The lower surface of the ridge 4g is inclined so as to approach the open end 5c in the counterclockwise direction.

[0049] A plurality of ridges 4g are provided on the outer peripheral surface of the inner bag 4, and the start and end points of the plurality of ridges 4g are offset from one another in the circumferential direction. In this embodiment, two ridges 4g are arranged 180 degrees apart in the circumferential direction. The angle at which each ridge 4g extends is preferably 180 degrees or less, and more preferably 90 degrees or less. This angle is, for example, 15 to 180 degrees, and preferably 30 to 90 degrees (approximately 45 degrees in this embodiment). Specifically, this angle may be, for example, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, or 180 degrees, or may be in a range between any two of the values ​​exemplified here.

[0050] A cam rail 3l is provided on the inner peripheral surface of the outer shell 3. A recess 3m that can engage with the protrusion 4g is provided in a portion of the cam rail 3l. The recess 3m is preferably provided at the end of the cam rail 3l. The upper surface of the cam rail 3l is inclined so as to approach the open end 3a as it progresses in the counterclockwise direction. The protrusion 4g and the recess 3m are configured to be engageable with each other by rotating the inner bag 4 clockwise relative to the outer shell 3, and to be disengaged by rotating the inner bag 4 counterclockwise relative to the outer shell 3. The recess 3m is configured as a non-through hole. In this case, cracks are less likely to occur in the outer shell 3 than when the recess 3m is configured as a through hole.

[0051] A plurality of cam rails 3l are provided on the inner peripheral surface of the outer shell 3, and the start and end points of the plurality of cam rails 3l are offset from one another in the circumferential direction. In this embodiment, two cam rails 3l are arranged offset by 180 degrees in the circumferential direction. The angle at which each cam rail 3l extends is preferably 360 degrees or less, and more preferably 270 degrees or less. This angle is, for example, 90 to 360 degrees, and preferably 120 to 240 degrees (180 degrees in this embodiment). Specifically, this angle may be, for example, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, or 360 degrees, or may be in a range between any two of the values ​​exemplified here.

[0052] The recessed strip 3m is preferably provided on each cam rail 31. The angle at which the recessed strip 3m extends is the same as the angle at which the protruding strip 4g extends.

[0053] The container body 2 is preferably provided with a rotation restriction structure that restricts relative rotation between the inner bag 4 and the outer shell 3. Examples of this rotation restriction structure include a structure that increases the frictional force between the inner bag 4 and the outer shell 3, and a structure that engages the inner bag 4 and the outer shell 3 in a circumferential direction.

[0054] Before the inner bag 4 is pulled out of the container body 2, the lower surface of the ridge 4g abuts against the upper surface of the cam rail 3l within the groove 3m. The ridge 4g and the cam rail 3l form a cam mechanism 31. When the inner bag 4 is rotated counterclockwise relative to the outer shell 3, the cam mechanism 31 causes the inner bag 4 to be displaced in a direction that allows it to come out of the container body 2. At this time, the inner bag 4 is twisted and its diameter is reduced. The cam mechanism 31 has an inclined structure that is inclined in the same direction as a right-handed screw.

[0055] As shown in Figures 5 and 6, the outer peripheral surface of the outer shell 3 is provided with first and second flange portions 3f1, 3f2 in this order from the opening end 3a of the outer shell 3. The cam mechanism 31 is preferably positioned so that its lower end is closer to the opening end 3a than the lower surface 3f3 (preferably the central surface 3f4, more preferably the upper surface 3f5) of the second flange portion 3f2. The container body 2 is formed by biaxially stretch blow molding the preform 15 shown in Figures 8 to 10, and the second flange portion 13f2 and cam mechanism 15g of the preform 15 become the second flange portion 3f2 and cam mechanism 31 of the container body 2 after molding. The cam mechanism 15g is composed of the ridge 14g of the inner preform 14 and the cam rail 13l of the outer preform 13. Since the preform 15 is heated and stretched mainly on the bottom 15c side rather than the undersurface 13f3 of the second flange portion 13f2, by arranging the cam mechanism 15g in a position closer to the open end 13d of the outer preform 13 than the undersurface 13f3 of the second flange portion 13f2, it is possible to prevent the shape of the cam mechanism 15g provided on the preform 15 from collapsing during molding. Similarly, it is preferable that the recessed ribs 3m and the protruding ribs 4g and the portions of the preform 15 corresponding to the recessed ribs 3m and the protruding ribs 4g are arranged in positions closer to the open ends 3a and 13d than the undersurfaces 3f3 and 13f3 of the second flange portions 3f2 and 13f2.

[0056] As shown in FIG. 5 , the first flange portion 3f1 is configured with an expanded diameter at the opening end 3a. A recess 3g is preferably provided on the inner peripheral surface of the first flange portion 3f1. The lower surface of the recess 3g serves as the inner bag support surface 3a3. The F-port standard stipulates that the axial length from the opening end 5c of the container body 2 to the lower surface of the support ring that supports the opening 5 when the opening attachment member 8 is attached is 10.2 mm. Therefore, if a single flange portion provided on the outer shell 3 is to comply with the F-port cap standard, the flange portion must be located at or adjacent to the opening end 3a, as with the first flange portion 3f1. In this case, heat is more likely to be applied to the cam mechanism 15g provided on the preform 15 during molding, making the shape of the cam mechanism 15g more likely to collapse during molding. On the other hand, in this embodiment, the first and second flange portions 3f1 and 3f2 are provided, thereby preventing the shape of the cam mechanism 15g provided on the preform 15 from collapsing during molding. The first flange portion 3f1 is provided as a support ring, and it is preferable that the first flange portion 3f1 does not engage with the mouth portion attachment member 8.

[0057] The length L7 between the lower surfaces of the first and second flange portions 3f1, 3f2 in the axial direction is, for example, 3 to 9 mm, and preferably 4.5 to 7.5 mm (6 mm in this embodiment).Specific examples of the length L7 are 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, and 9.0 mm, and may be in a range between any two of the values ​​exemplified here.

[0058] <Detailed Configuration of Mouth Attachment Member 8> As shown in Fig. 4, the mouth attachment member 8 preferably has a discharge port 8d for discharging the contents in the inner bag 4. In addition, the mouth attachment member 8 preferably includes a nozzle 8c.

[0059] The spout-mounted member 8 preferably includes a main body member 41 and an opening / closing member 42. When the spout-mounted member 8 is a cap 8a, the main body member 41 is the cap main body, and the opening / closing member 42 is an overcap. The main body member 41 is configured to be able to engage with the protrusion 4c and includes a discharge port 8d. The opening / closing member 42 is configured to be able to open and close the discharge port 8d. FIG. 3 shows a closed state in which the discharge port 8d is closed, and FIG. 4 shows an open state in which the discharge port 8d is open. In this embodiment, the main body member 41 and the opening / closing member 42 are connected by a hinge 43, but they do not have to be connected. The opening / closing member 42 is preferably able to engage with the main body member 41 by a screw or a snap fit.

[0060] The main body member 41 includes an outer tube 41a, an inner tube 41b, a nozzle 8c, and an upper wall 41d. The inner tube 41b is disposed inside the outer tube 41a. The outer tube 41a and inner tube 41b are connected via the upper wall 41d. The nozzle 8c is disposed above the upper wall 41d. A flow hole 41i is provided in the upper wall 41d, and the flow passages of the inner tube 41b and the nozzle 8c are connected through the flow hole 41i. The tip of the nozzle 8c forms the discharge port 8d. The inner tube 41b is inserted into the protruding portion 4c and is in close contact with the inner surface 4f1 of the cylindrical seal portion 4f. As a result, the inner tube 41b and the cylindrical seal portion 4f are frictionally engaged in the circumferential direction. An engagement portion 8b is provided on the inner peripheral surface of the outer tube 41a.

[0061] The opening / closing member 42 includes an outer tube 42a, an inner tube 42b, and an upper wall 42d. The inner tube 42b is disposed inside the outer tube 42a. The outer tube 42a and the inner tube 42b are connected via the upper wall 42d. The upper wall 42d does not have a discharge port for discharging the contents of the inner bag 4.

[0062] When the discharge port 8d is closed by the opening / closing member 42, the inner tube 42b is inserted into the nozzle 8c of the main body member 41 and is in close contact with the inner surface of the nozzle 8c. The bottom surface of the outer tube 42a abuts against the upper wall 41d of the main body member 41. From this state, by gripping the outer tube 42a and applying an upward force to the opening / closing member 42, the opening / closing member 42 can be separated from the main body member 41 to open the discharge port 8d.

[0063] 3 and 4, the mouth portion attachment member 8 can be attached to the mouth portion 5 with the first flange portion 3f1 supported. The mouth portion attachment member 8 is preferably of a plugging type, and with the first flange portion 3f1 supported, the mouth portion attachment member 8 is placed over the protruding portion 4c. When a downward force is applied to the mouth portion attachment member 8 in this state, the engaging portion 8b overcomes the axial engaging portion 4ma, and the engaging portion 8b engages with the axial engaging portion 4ma and the circumferential engaging portion 4mb, and the mouth portion attachment member 8 can be attached to the mouth portion 5.

[0064] <Removal of inner bag 4> The mouth attachment member 8 is engaged with the mouth 5 of the inner bag 4 in the circumferential and axial directions, and is configured so that the inner bag 4 rotates at the mouth 5 relative to the outer shell 3 as the mouth attachment member 8 rotates. The inner bag 4 is configured to move in a direction to come out of the container body 2 as the inner bag 4 rotates due to the action of a cam mechanism 31 provided between the inner bag 4 and the outer shell 3. Furthermore, since the inner bag 4 is less likely to rotate relative to the outer shell 3 at the body 6 and bottom 7 than at the mouth 5, rotating the inner bag 4 relative to the outer shell 3 at the mouth 5 causes the inner bag 4 to twist.

[0065] With this configuration, by rotating the mouth attachment member 8, the inner bag 4 can be twisted and moved in a direction that allows it to come out of the container body 2, and then by pulling the mouth attachment member 8, the inner bag 4 can be pulled out of the container body 2.

[0066] 1-2. Manufacturing method of container 11 The container body 2 can be manufactured by biaxially stretching blow molding a preform 15 shown in Fig. 9. The container 11 can also be manufactured by attaching a mouth attachment member 8 to the container body 2.

[0067] <Configuration of Inner Preform 14 , Outer Preform 13 , and Preform 15 > As shown in FIG. 8 , the preform 15 includes the inner preform 14 that will become the inner bag 4 and the outer preform 13 that will become the outer shell 3 .

[0068] As shown in Fig. 8, the inner preform 14 is cylindrical with a bottom and includes a mouth 14a, a body 14b, and a bottom 14c. The bottom 14c is provided so as to close the lower end of the body 14b. The outer preform 13 is cylindrical with a bottom and includes a mouth 13a, a body 13b, and a bottom 13c. The bottom 13c is provided so as to close the lower end of the body 13b.

[0069] 9, a preform 15 can be formed by covering the inner preform 14 with the outer preform 13. In the preform 15, the mouth portion 14a faces the mouth portion 13a, and the body portion 14b faces the body portion 13b.

[0070] 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 primarily stretched in the biaxially stretch blow molding. The mouth portion 15a is hardly deformed during molding and becomes the mouth portion 5 of the container body 2. The above-described contents regarding the configuration included in the mouth portion 5 can also be applied to the configuration included in the mouth portion 15a, as long as it does not contradict the intent thereof.

[0071] <Materials and manufacturing method of inner preform 14, outer preform 13, and preform 15> The inner preform 14 and outer preform 13 can be formed by direct blow molding or injection molding using a thermoplastic resin such as polyester (e.g., PET) or polyolefin (e.g., polypropylene, polyethylene).

[0072] The outer preform 13 is preferably formed by injection molding. The inner preform 14 is preferably formed by direct blow molding using a molten cylindrical parison. When the inner preform 14 is formed by direct blow molding, a structure in which a recess 4c13 is formed on the inner peripheral surface of the axial engagement portion 4ma can be obtained. The inner preform 14 preferably has a multi-layer structure.

[0073] In one example, the inner preform 14 can be formed by direct blow molding using a split mold that opens to the left and right along the parting line PL shown in FIG. 10B. The inner preform 14 is provided with engaging protrusions 14c2 that become the engaging protrusions 4c2. As shown in FIG. 10B, the inner preform 14 is provided with eight engaging protrusions 14c2. Four engaging protrusions 14c2 (14c21, 14c22, 14c23, and 14c24) located in regions C to F in FIG. 10B have the shapes shown in FIGS. 10C to 10F. The remaining four engaging protrusions 14c2 in FIG. 10B have shapes that are point-symmetrical to the engaging protrusions 14c21, 14c22, 14c23, and 14c24. The engaging protrusions 14c21, 14c22, 14c23, and 14c24 are each formed in a shape that prevents undercuts when the split mold is opened in the left-right direction to remove the inner preform 14. This prevents the engaging protrusions 14c21, 14c22, 14c23, and 14c24 from losing their shape when the inner preform 14 is removed from the split mold.

[0074] 2. Other Embodiments The direction in which each component is rotated relative to the other may be reversed. In the above embodiment, the inner bag 4 is displaced in a direction in which it comes out of the container body 2 when the clockwise screw is rotated in the loosening direction. However, the inner bag 4 may be displaced in a direction in which it comes out of the container body 2 when the counterclockwise screw is rotated in the loosening direction.

[0075] (Second Aspect) 1. Configuration of the Double Container 1 A double container 1 according to an embodiment of the second aspect of the present invention will be described with reference to Figures 11 to 19. The matters described in the first aspect are applicable to this aspect as long as they do not contradict the spirit of the first aspect, and the matters described in this aspect are applicable to the first aspect as long as they do not contradict the spirit of the first aspect. The following description will focus on the differences from the first aspect.

[0076] <Overall Configuration> As shown in Figures 11 and 12, the double container 1 of this embodiment includes a container body 2, a spout attachment member 8 (a pump 9 in this embodiment), an engaging member 45, and a sealing member 46. The container body 2 is configured so that, when viewed from above the double container 1, rotating the inner bag 4 in one direction relative to the outer shell 3 displaces the inner bag 4 in a direction that causes it to slip out of the container body 2. The spout attachment member 8 and the protrusion 4c are configured to be threadably engageable with each other such that rotation of the spout attachment member 8 relative to the protrusion 4c in this one direction loosens the threaded engagement. In this embodiment, this one direction is a counterclockwise direction as viewed from above the double container 1. Hereinafter, "clockwise" and "counterclockwise" refer to directions as viewed from above the double container 1, unless otherwise specified. Each component will be described in detail below.

[0077] <Basic structure of container body 2> As shown in Fig. 12, the container body 2 includes a mouth 5, a body 6, and a bottom 7. A flange 5b is provided on the mouth 5. The flange 5b can be used to support the mouth 5 when a mouth attachment member 8 is attached to the mouth 5. The body 6 is disposed adjacent to the mouth 5 on a side farther from the open end 5c than the mouth 5. In one example, the body 6 is located below the flange 5b.

[0078] The double container 1 of this embodiment may be configured so that the inner bag 4 contracts as the contents are dispensed. In this case, the mouth attachment member 8 is provided with a check valve that allows the contents to be dispensed and prevents outside air from entering the inner bag 4. In this case, the container body 2 is also provided with an outside air inlet for introducing outside air into the space between the outer shell 3 and the inner bag 4.

[0079] <Detailed Configuration of Outer Shell 3 and Inner Bag 4> As shown in Fig. 13, 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 is provided with a protruding tube 4c1, a male thread portion 4c9, and an uneven portion 4i. The uneven portion 4i is located farther from the open end 5c than the male thread portion 4c9. The uneven portion 4i is configured by recessed portions 4i1 and protruding portions 4i2 that are arranged alternately in the circumferential direction. In this embodiment, 12 recessed portions 4i1 and 12 protruding portions 4i2 are arranged alternately in the circumferential direction.

[0080] A flange 4c10 is provided on the inner bag 4. The flange 4c10 is provided so as to protrude in the radial direction. The flange 4c10 is preferably provided around the entire circumference. An uneven portion 4i is provided between the flange 4c10 and the male thread portion 4c9. The flange 4c10 is provided adjacent to the uneven portion 4i.

[0081] As shown in FIGS. 14 and 15 , the lower surface 4c11 of the flange 4c10 abuts against the outer shell 3. The lower surface 4c11 abuts against the inner bag support surface 3a3 provided on the outer shell 3. Support of the lower surface 4c11 of the flange 4c10 by the inner bag support surface 3a3 prevents the inner bag 4 from falling into the outer shell 3. The inner bag support surface 3a3 may be flush with the base surface 3a1 of the opening end 3a, or may be provided at a higher or lower position than the base surface 3a1. In this embodiment, the inner bag support surface 3a3 is provided at a lower position than the base surface 3a1. Therefore, a portion of the flange 4c10 is disposed within the outer shell 3, and the remainder is disposed outside the outer shell 3. The flange 4c10 may be disposed entirely within the outer shell 3, or entirely outside the outer shell 3. When the inner bag 4 is formed by direct blow molding, the flange 4c10 tends to have low strength and is easily damaged when dropped, but damage to the flange 4c10 is suppressed by disposing at least a portion of the flange 4c10 inside the outer shell 3. In one example, the flange 4c10 is hollow.

[0082] <Detailed Configuration of Engaging Member 45> As shown in Figures 12 to 17, the engaging member 45 is a member that engages with the protruding portion 4c in the circumferential direction. The engaging member 45 may be annular or non-annular. If the engaging member 45 is annular, the engaging member 45 may be circular or non-circular in plan view (i.e., when viewed axially from above the double container 1). Furthermore, it is sufficient for the engaging member 45 to be circumferentially engaged with the protruding portion 4c to an extent that it can rotate integrally with the protruding portion 4c. It is not necessary for the engaging member 45 to cover the entire circumference of the protruding portion 4c; it is sufficient for it to cover at least a portion of the circumferential direction of the protruding portion 4c. The angle at which the engaging member 45 covers the protrusion 4c is, for example, 180 to 360 degrees, and more specifically, for example, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, or 360 degrees, or may be in a range between any two of the values ​​exemplified here.

[0083] In this embodiment, the engaging member 45 is an annular member having an opening 45a. The protruding portion 4c is disposed within the opening 45a. In other words, the engaging member 45 is disposed so as to surround the protruding portion 4c. As shown in FIGS. 16 and 17 , an uneven portion 45c is provided on a peripheral surface 45b of the opening 45a. The uneven portion 45c is configured by alternately arranging recessed portions 45c1 and protruding portions 45c2 in the circumferential direction. In this embodiment, 12 recessed portions 45c1 and 12 protruding portions 45c2 are alternately provided in the circumferential direction.

[0084] As shown in FIGS. 14 , 16C , and 17 , when the engaging member 45 is attached to the protruding portion 4c, the convex portions 45c2 on the engaging member 45 are disposed between the adjacent convex portions 4i2 on the protruding portion 4c. Therefore, the concave-convex portions 4i and 45c form a circumferential engaging portion 47, through which the engaging member 45 and the protruding portion 4c are circumferentially engaged. In the circumferential engaging portion 47, the peripheral surface 45b of the opening 45a and the outer peripheral surface 4c12 of the protruding portion 4c are circumferentially engaged. In this embodiment, the engaging member 45 and the protruding portion 4c are circumferentially engaged with each other. The circumferential engaging portion 47 is disposed farther from the opening end 5c than the male thread portion 4c9. The circumferential engaging portion 47 is also disposed between the male thread portion 4c9 and the flange 4c10.

[0085] At the circumferential engagement portion 47, the engagement member 45 and the protrusion 4c are circumferentially engaged with each other so that when the engagement member 45 is rotated counterclockwise relative to the outer shell 3, the inner bag 4 rotates relative to the outer shell 3 before the engagement member 45 rotates relative to the protrusion 4c. The engagement at the circumferential engagement portion 47 may be a concave-convex engagement or a frictional engagement. If the torque required to rotate the inner bag 4 counterclockwise relative to the outer shell 3 is T1 and the torque required to rotate the engagement member 45 counterclockwise relative to the protrusion 4c is T2, T2 / T1 is greater than 1, preferably 1.2 or greater, and more preferably 2 or greater. This value may be, for example, 1.2, 1.5, 2, 5, 10, or 100, or may be in a range between or greater than any two of the values ​​exemplified herein.

[0086] As shown in Figures 12 and 15, the engaging member 45 includes a cylindrical portion 45d and a top surface portion 45e provided on the top surface of the cylindrical portion 45d. The opening 45a is provided in the top surface portion 45e. As shown in Figures 14 to 15, the upper surface 4c14 of the flange 4c10 abuts against the top surface portion 45e. The cylindrical portion 45d is disposed so as to surround the outer shell 3. This configuration facilitates stable rotation of the engaging member 45. An open end 45h of the cylindrical portion 45d faces the flange 5b. An outer peripheral surface 45d1 of the cylindrical portion 45d and an outer peripheral surface 5b1 of the flange 5b are flush with each other.

[0087] <Mouth Attachment Member 8 and Seal Member 46> As shown in FIG. 12, the mouth attachment member 8 is attached to the mouth 5 of the container body 2. As shown in FIGS. 14 and 15, the mouth attachment member 8 has a female threaded portion 8b1 that can be threaded with the male threaded portion 4c9. By threading the male threaded portion 4c9 and the female threaded portion 8b1, the mouth attachment member 8 is attached to the protrusion 4c provided on the mouth 5 of the inner bag 4. The seal member 46 is a member that enhances adhesion between the container body 2 and the mouth attachment member 8 to prevent leakage of the contents of the container body 2. The seal member 46 is preferably made of an elastic material such as rubber. The seal member 46 has an opening 46a for allowing the contents to flow through. The seal member 46 is disposed on the open end 5c. In this embodiment, the mouth attachment member 8 is a pump 9, but it may also be another member such as a cap. The seal member 46 can be omitted if unnecessary.

[0088] When the mouth attachment member 8 is rotated counterclockwise relative to the outer shell 3, it is preferable that the mouth attachment member 8 and the protrusion 4c rotate relative to each other in the circumferential direction before the inner bag 4 rotates relative to the outer shell 3. In this case, there is a risk that the mouth attachment member 8 will rotate relative to the protrusion 4c before the inner bag 4 rotates relative to the outer shell 3, making the significance of applying the present invention particularly significant. If the torque required to rotate the inner bag 4 counterclockwise relative to the outer shell 3 is T1 and the torque required to rotate the mouth attachment member 8 counterclockwise relative to the protrusion 4c is T3, then T3 / T1 is less than 1, preferably 0.9 or less, and more preferably 0.8 or less. This value is, for example, 0.1 to 0.99, and specifically, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, or 0.99, and may be within a range between any two of the values ​​exemplified herein.

[0089] The pump 9 is configured to suck and discharge the contents of the container body 2 (more specifically, the inner bag 4). As shown in Figures 12 and 14-15, the pump 9, in one example, includes a cylindrical portion 9a, a nozzle 9b, a piston portion 9c, a pump mechanism portion 9d, and a tube 9e. The pump 9 is configured to slide the piston portion 9c to activate the pump mechanism within the pump mechanism portion 9d, thereby allowing the contents sucked up through the tube 9e to be discharged from the nozzle 9b communicating with the piston portion 9c. The tube 9e can be omitted if not needed. The nozzle 9b is provided on a head 9f, and the piston portion 9c can be slid as the head 9f is pressed and released.

[0090] As shown in FIG. 14 , the cylindrical portion 9a includes a threaded cylindrical portion 9a1, a top surface portion 9a2, and a sliding cylindrical portion 9a3. The top surface portion 9a2 is provided on the top surface of the threaded cylindrical portion 9a1. The sliding cylindrical portion 9a3 is provided on the top surface portion 9a2. The threaded cylindrical portion 9a1 and the sliding cylindrical portion 9a3 are connected to each other and are preferably arranged concentrically. A female thread portion 8b1 is provided on the inner circumferential surface of the threaded cylindrical portion 9a1. The lower end 9a4 of the cylindrical portion 9a faces the top surface portion 45e. In other words, the top surface portion 45e is disposed between the flange 4c10 and the cylindrical portion 9a. In this embodiment, a gap is provided between the upper surface 45g of the top surface portion 45e and the lower end 9a4. However, this gap may be eliminated, or the top surface portion 45e may be sandwiched and fixed between the flange 4c10 and the cylindrical portion 9a. Furthermore, a protrusion that can come into contact with the upper surface 45g of the top surface 45e may be provided on the inner bag 4, and the top surface 45e may be positioned between the flange 4c10 and the protrusion to fix the top surface 45e. In this case, the engaging member 45 can be attached so as to climb over the protrusion of the inner bag 4.

[0091] A flange 9g is provided on the outer peripheral surface of the pump mechanism 9d. The flange 9g is disposed between the top surface 9a2 and the open end 5c. A seal member 46 is preferably disposed between the flange 9g and the open end 5c. With this configuration, by rotating the tubular portion 9a clockwise relative to the protruding portion 4c and tightening it, the flange 9g (and the seal member 46) are clamped between the top surface 9a2 and the open end 5c, forming a seal structure that prevents leakage of the contents.

[0092] The head 9f includes a cylindrical portion 9f1. When a downward force is applied to the head 9f, the sliding cylindrical portion 9a3 enters the cylindrical portion 9f1 and the head 9f moves downward, at which time the head 9f presses down the piston portion 9c, thereby operating the pump mechanism in the pump mechanism portion 9d.

[0093] 2. Manufacturing the double container 1 and removing the inner bag 4 The double container 1 of this embodiment can be manufactured by filling the container body 2 with the contents and then attaching the engaging member 45 and the opening attachment member 8.

[0094] The engaging member 45 is circumferentially engaged with the protruding portion 4c of the inner bag 4, and is configured so that the inner bag 4 rotates relative to the outer shell 3 as the engaging member 45 rotates. By rotating the inner bag 4 relative to the outer shell 3, the inner bag 4 can be twisted and reduced in diameter. Also, due to the action of a cam mechanism 31 provided between the inner bag 4 and the outer shell 3, the inner bag 4 moves in a direction that removes it from the container body 2 as the inner bag 4 rotates. Therefore, by rotating the engaging member 45, the inner bag 4 can be moved in a direction that removes it from the container body 2 while being twisted and reduced in diameter.

[0095] Furthermore, the spout attachment member 8 is axially engaged with the protruding portion 4c by screwing. Furthermore, if the circumferential engagement portion 47 is positioned farther from the open end 5c than the male thread portion 4c9, when an attempt is made to pull the engagement member 45 in the axial direction to remove the inner bag 4, the engagement member 45 will come into contact with the spout attachment member 8. Therefore, the engagement member 45 is axially engaged with the protruding portion 4c via the spout attachment member 8. With this configuration, the inner bag 4 can be removed from the container body 2 by grasping the spout attachment member 8 and / or the engagement member 45 and pulling them in the axial direction.

[0096] In this way, in the double container 1 of this embodiment, there is no need to apply torque to the opening attachment member 8 when pulling out the inner bag 4, so a screw-type opening attachment member 8 can be used.

[0097] After the inner bag 4 is removed, the spout attachment member 8 can be rotated relative to the inner bag 4 in a direction that loosens the screw connection, thereby separating the spout attachment member 8 and the inner bag 4. Furthermore, after separating the spout attachment member 8, the engaging member 45 can be moved axially relative to the inner bag 4 to separate the engaging member 45 and the inner bag 4. The double-walled container 1 of this embodiment is highly recyclable because the multiple components constituting the double-walled container 1 are configured to be easily separable. After separation, the inner bag 4 and the outer shell 3 can be recycled separately. The other components may be recycled or reused. For example, a container body 2 filled with contents can be purchased, and the engaging member 45, sealing member 46, and spout attachment member 8 can be attached to it to regenerate the double-walled container 1 filled with contents. By distributing the container body 2 filled with contents without the engaging member 45 attached, it is possible to prevent the engaging member 45 from being rotated by tampering or other means during distribution.

[0098] 3. Manufacturing Method of Container Body 2 of Double Container 1 The container body 2 can be manufactured by biaxially stretching blow molding the preform 15 shown in Fig. 19. The preform 15 can be formed by covering the inner preform 14 shown in Fig. 18 with the outer preform 13.

[0099] 4. Other Embodiments The direction of relative rotation of each component may be reversed from that of the above embodiment. In the above embodiment, the inner bag 4 is configured to be displaced in a direction that removes it from the container body 2 when the clockwise thread is rotated in the loosening direction, and the threaded engagement between the spout attachment member 8 and the protrusion 4c is released. However, the inner bag 4 may be configured to be displaced in a direction that removes it from the container body 2 when the counterclockwise thread is rotated in the loosening direction, and the threaded engagement between the spout attachment member 8 and the protrusion 4c is released. In this case, the "one direction" referred to in the above embodiment refers to the clockwise direction, and "counterclockwise" in the description of the above embodiment is replaced with "clockwise" and "clockwise" is replaced with "counterclockwise".

[0100] The cam mechanism 31 can be omitted. If the cam mechanism 31 is omitted, the inner bag 4 will not be displaced in a direction that causes it to come out of the container body 2 even when it is rotated relative to the outer shell 3. However, by rotating the inner bag 4 relative to the outer shell 3, the inner bag 4 can be twisted and reduced in diameter, which makes it easier to pull the inner bag 4 out of the container body 2.

[0101] The spout attachment member 8 may be attached to the protrusion 4c in a manner different from that of the above embodiment, for example, it may be attached to the protrusion 4c in a stoppered manner. The spout attachment member 8 may or may not be circumferentially engaged with the protrusion 4c. On the other hand, as in the above embodiment, the significance of applying the present invention becomes apparent when, when the spout attachment member 8 is rotated counterclockwise relative to the outer shell 3, the spout attachment member 8 and the protrusion 4c rotate relative to each other in the circumferential direction before the inner bag 4 rotates relative to the outer shell 3. The preferred range of T3 / T1 is also the same as in the above embodiment.

[0102] (Third Viewpoint) A double container 1 according to an embodiment of the third viewpoint of the present invention will be described with reference to Figures 20 to 24. The matters described in the first viewpoint are applicable to this viewpoint as long as they do not contradict the spirit of the first viewpoint, and the matters described in this viewpoint are applicable to the first viewpoint as long as they do not contradict the spirit of the first viewpoint. The following description will focus on the differences from the first viewpoint.

[0103] 1-1. Configuration of the double container 1 As shown in Figure 20, the double container 1 of one embodiment of the present invention comprises a container body 2 and a spout attachment member 8. The contents are accommodated in the container body 2. One example of the contents is a high-viscosity substance having a viscosity of 100 mPa·s or more at 20°C. Examples of high-viscosity substances include ketchup, mayonnaise, and honey. The viscosity of the high-viscosity substance at 20°C is preferably 500 mPa·s or more, more preferably 1000 mPa·s or more, and even more preferably 5000 mPa·s or more. The upper limit of the viscosity of the high-viscosity substance at 20°C is not particularly specified, but is, for example, 10,000, 50,000, or 100,000 mPa·s.

[0104] 21 to 24, the container body 2 includes an inner bag 4 and an outer shell 3 disposed so as to cover the inner bag 4. The inner bag 4 is configured to be removable from the container body 2.

[0105] The container body 2 has a mouth 5, a body 6, and a bottom 7. The mouth 5 is a tubular (preferably cylindrical) portion having an open end 5c. The open end 5c is the open end of the container body 2 and also the open end of the inner bag 4.

[0106] The body 6 is disposed adjacent to the mouth 5, farther from the open end 5c than the mouth 5. The body 6 is cylindrical, and the bottom 7 is provided at the lower end of the body 6 and closes the lower end of the body 6. The body 6 includes a shoulder 6b whose circumferential length in a cross section perpendicular to the axial direction increases with increasing distance from the mouth 5. "Circumferential length" refers to the length of the outer periphery in a cross section perpendicular to the axial direction, as shown in Figures 24A to 24C. A decrease in circumferential length and an increase in circumferential length are also referred to as "reduced diameter" and "expanded diameter," respectively. The body 6 also includes a body main body 6c located closer to the bottom 7 than the shoulder 6b. The body main body 6c has, for example, a shape in which the outer diameter is substantially constant toward the bottom 7, or a shape in which the diameter decreases toward the bottom 7. In the following description, the portion below the lower surface 3f3 of the second flange 3f2 shown in Figure 22, excluding the bottom 7, is referred to as the body 6.

[0107] 22 to 24 , where H denotes the overall height of the container body 2, the portion of the body 6 where the perimeter in a cross section perpendicular to the axial direction is the maximum is the maximum perimeter portion 2a, and the height of the maximum perimeter portion 2a from the bottom surface 7a of the container body 2 is Hmax, Hmax / H is 0.20 to 0.40 (0.30 in this embodiment). In this manner, in this embodiment, the maximum perimeter portion 2a is located at a low position on the container body 2, so the body 6 of the container body 2 can be gradually expanded in diameter from the opening 5 of the container body 2 toward the maximum perimeter portion 2a. If the body 6 of the container body 2 were to rapidly expand in diameter, friction between the inner bag 4 and the outer shell 3 would increase when the inner bag 4 is pulled out, and the force required to pull out the inner bag 4 would likely increase. However, in this embodiment, the body 6 of the container body 2 is gradually expanded in diameter toward the maximum perimeter portion 2a, thereby reducing the force required to pull out the inner bag 4.

[0108] Hmax / H is preferably 0.25 to 0.35, specifically, for example, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, or may be in a range between any two of the values ​​exemplified here. H is, for example, 150 to 180 mm (164 mm in this embodiment), and is preferably 160 to 170 mm, specifically, for example, 150, 155, 160, 165, 170, 175, 180 mm, or may be in a range between any two of the values ​​exemplified here. Hmax is, for example, 40 to 60 mm (49 mm in this embodiment), preferably 45 to 55 mm, and specifically, for example, 40, 45, 50, 55, or 60 mm, or may be in a range between any two of the values ​​exemplified here.

[0109] As shown in Figure 24C, if the outer diameter (i.e., the "distance between the outer surfaces") in the major axis direction (left-right direction in Figure 22) at which the outer diameter is greatest at the maximum circumferential length portion 2a is DLmax and the outer diameter in the minor axis direction (left-right direction in Figure 23A) perpendicular to the major axis direction is DSmax, then DSmax / DLmax is 0.70 to 0.95 (0.83 in this embodiment). As such, in this embodiment, the container body 2 has a flattened shape at the maximum circumferential length portion 2a, making it easy to crush the container body 2 and dispense the contents. DSmax / DLmax is preferably 0.75 to 0.90, and specifically, for example, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, and may be in a range between any two of the numerical values ​​exemplified here. DLmax is, for example, 50 to 75 mm (62 mm in this embodiment), preferably 55 to 70 mm, and specifically, for example, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, or 75 mm, or may be in a range between any two of the numerical values ​​exemplified here. DSmax is, for example, 40 to 60 mm (51 mm in this embodiment), preferably 45 to 55 mm, and specifically, for example, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60 mm, or may be in a range between any two of the numerical values ​​exemplified here.

[0110] The wall thickness at the portion 2a1 of the maximum circumferential length portion 2a that is farthest from the central axis C is defined as TL, and the wall thickness at the portion 2a2 that is closest to the central axis C is defined as TS. TL / TS is, for example, 0.70 to 0.95 (0.83 in this embodiment). When discharging the contents from the double-walled container 1, the container body 2 is typically deformed so as to be crushed in the direction of its short side. When TL / TS is within the above-mentioned numerical range, the wall thickness at the portion 2a2 that is pressed when crushing the container body 2 is relatively large, and the wall thickness at the portion 2a1 that is bent when crushing the container body 2 is relatively small, making it easy to crush the container body 2 and to dispense the contents. The preferred numerical range for TL / TS is the same as that described above for DSmax / DLmax. Since the thickness of the container body 2 is inversely proportional to the degree of stretching (blow ratio) during blow molding, when the container body 2 is formed using a preform 15 (shown in FIG. 30) that is circular in cross section and has a constant thickness in the circumferential direction, the thickness of the container body 2 decreases the farther away from the central axis C. For this reason, it is preferable that TL / TS is proportional to DSmax / DLmax.

[0111] The minimum circumferential length portion 2b is the portion of the barrel 6 where the circumferential length in a cross section perpendicular to the axial direction is smallest. In this embodiment, the barrel 6 is slightly reduced in diameter from the lower surface 3f3 of the second flange portion 3f2 toward the minimum circumferential length portion 2b, and then gradually expanded in diameter toward the maximum circumferential length portion 2a, where the circumferential length is greatest, and then gradually reduced in diameter toward the bottom surface 7a.

[0112] If the height of the minimum circumferential length portion 2b from the bottom surface 7a of the container body 2 is Hmin and the outer diameter of the minimum circumferential length portion 2b in the major axis direction is DLmin, then (DLmax - DLmin) / (Hmin - Hmax) (hereinafter referred to as the "first diameter expansion index") is preferably 0.26 to 0.46 (0.36 in this embodiment). The first diameter expansion index is calculated by dividing the difference in outer diameter between the maximum circumferential length portion 2a and the minimum circumferential length portion 2b by the height distance, and is an index indicating the degree of diameter expansion in the body portion 6. The smaller the first diameter expansion index, the more gradually the container body 2 expands in diameter from the minimum circumferential length portion 2b toward the maximum circumferential length portion 2a, making it easier to pull out the inner bag 4. Because the maximum circumferential length portion 2a is located at a low position on the container body 2, the value of (Hmin - Hmax) is relatively large, and therefore the first diameter expansion index is relatively small. The first expansion index is preferably 0.30 to 0.42, and specifically, for example, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, and may be in a range between any two of the numerical values ​​exemplified here.

[0113] Hmin / H is preferably 0.80 to 0.90 (0.85 in this embodiment). Because the minimum circumferential length portion 2b is located at a high position on the container body 2, it is easy to increase the internal volume of the container body 2 and to reduce the value of the first diameter expansion index. Specific examples of Hmin / H are 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, and 0.90, and may be in a range between any two of the values ​​exemplified here. DLmin / DLmax is, for example, 0.38 to 0.58 (0.48 in this embodiment), preferably 0.43 to 0.53, and specifically, for example, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, and may be in a range between any two of the numerical values ​​exemplified here.

[0114] If the outer diameter in the minor axis direction at the minimum circumferential length portion 2b is DSmin, then DSmin / DLmin is, for example, 0.90 to 1.00 (1.00 in this embodiment). Thus, the container body 2 is substantially circular at the minimum circumferential length portion 2b. The container body 2 has a shape that gradually becomes flatter from the minimum circumferential length portion 2b toward the maximum circumferential length portion 2a. DSmin / DLmin is preferably 0.95 to 1.00, and specifically, for example, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, or 1.00, and may be in a range between any two of the values ​​exemplified here.

[0115] The body 6 preferably includes an inwardly convex curved portion 6d that is convex inward and an outwardly convex curved portion 6e that is convex outward. The outwardly convex curved portion 6e is located closer to the bottom surface 7a than the inwardly convex curved portion 6d. The maximum circumferential length portion 2a is located in the outwardly convex curved portion 6e. If the height from the bottom surface 7a of a boundary portion 6f between the inwardly convex curved portion 6d and the outwardly convex curved portion 6e is Hb and the outer diameter in the major axis direction at the boundary portion 6f is DLb, then (DLmax - DLb) / (Hb - Hmax) (hereinafter referred to as the "second diameter expansion index") is preferably 0.28 to 0.48 (0.38 in this embodiment). The second diameter expansion index is calculated by dividing the difference in outer diameter between the maximum circumferential length portion 2a and the boundary portion 6f by the distance in the height direction, and is an index indicating the degree of diameter expansion between the maximum circumferential length portion 2a and the boundary portion 6f. The smaller the second diameter expansion index, the more gradually the container body 2 expands in diameter from the boundary portion 6f toward the maximum circumferential portion 2a, which means that it is easier to pull out the inner bag 4. At the outwardly convex curved portion 6e, friction between the inner bag 4 and the outer shell 3 increases when the inner bag 4 is pulled out, and a large force is likely to be required to pull out the inner bag 4. However, in this embodiment, the body 6 of the container body 2 gradually expands in diameter from the boundary portion 6f toward the maximum circumferential portion 2a, thereby reducing the force required to pull out the inner bag 4. The second expansion index is preferably 0.33 to 0.43, and specifically, for example, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, and may be in a range between any two of the numerical values ​​exemplified here.

[0116] Hb / H is preferably 0.45 to 0.75 (0.60 in this embodiment). The boundary 6f is preferably provided near the center between the minimum circumferential length portion 2b and the maximum circumferential length portion 2a. In this case, the force required to pull out the inner bag 4 is particularly likely to be reduced. Hb / H is preferably 0.50 to 0.70, and specific examples thereof include 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, and 0.75, and may be in a range between any two of the numerical values ​​exemplified here. DLb / DLmax is, for example, 0.60 to 0.80 (0.70 in this embodiment), preferably 0.65 to 0.75, and specifically, for example, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, and may be in a range between any two of the numerical values ​​exemplified here.

[0117] If the outer diameter in the minor axis direction at the boundary portion 6f is DSb, then DSb / DLb is, for example, 0.76 to 0.96 (0.86 in this embodiment). Thus, the container body 2 is slightly flattened at the boundary portion 6f. The container body 2 has a shape that gradually becomes flatter from the boundary portion 6f toward the maximum circumferential length portion 2a. DSb / DLb is preferably 0.81 to 0.91, and specifically, for example, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, or 0.96, and may be in a range between any two of the values ​​exemplified here.

[0118] <Discharge of Contents> In one example, the double container 1 is a squeeze-type container. In this case, the double container 1 can be tilted so that the mouth attachment member 8 faces diagonally downward. By squeezing the body 6 in this state, the contents in the inner bag 4 can be discharged through the mouth attachment member 8. When the body 6 is released from compression after the contents are discharged, the outer shell 3 returns to its original shape due to its restoring force. If outside air easily enters the inner bag 4, the outer shell 3 and the inner bag 4 will return to their original shapes together. However, if the outer shell easily enters the intermediate space between the inner bag 4 and the outer shell 3, outside air will enter this intermediate space, and the outer shell 3 will separate from the inner bag 4 and return to its original shape. If the mouth attachment member 8 is provided with a check valve, outside air will not enter the inner bag 4, but will instead enter the intermediate space. Even if the mouth attachment member 8 is not provided with a check valve, if the contents are highly viscous, the contents may at least partially block the discharge port 8d, preventing outside air from entering the inner bag 4. This tendency is more pronounced as the inner diameter of the discharge port 8d becomes smaller. Furthermore, if an outside air inlet hole is provided in the outer shell 3, outside air is introduced into the intermediate space through the outside air inlet hole. However, even if the outer shell 3 does not have an outside air inlet hole, outside air may be introduced into the intermediate space through the gap between the outer shell 3 and the inner bag 4 at the opening 5. When outside air is introduced into the intermediate space, the amount of air contained in the inner bag 4 decreases accordingly. The smaller the amount of air contained in the inner bag 4, the more easily the diameter of the inner bag 4 is reduced when the inner bag 4 is pulled out. Therefore, by configuring the inner bag 4 so that outside air can be easily introduced into the intermediate space, the ease of pulling out the inner bag 4 can be improved.

[0119] (Fourth Aspect) 1. First Embodiment A double-layered container 1 according to a first embodiment of the fourth aspect of the present invention will be described using Figures 25 to 31. The matters described in the first aspect are applicable to this aspect as long as they do not contradict the spirit of the first aspect, and the matters described in this aspect are applicable to the first aspect as long as they do not contradict the spirit of the first aspect. The following description will focus on the differences from the first aspect. In the following description, the "axial direction" refers to the direction in which the central axis C (shown in Figure 26) of the mouth portion 5 extends, and is, for example, the direction in which the inner bag 4 is pulled out from the container body 2.

[0120] 25 to 27, the double container 1 of the first embodiment of the present invention comprises a container body 2 and a spout attachment member 8. The container body 2 comprises an inner bag 4 and an outer shell 3 arranged to cover the inner bag 4.

[0121] <Engagement structure between container body 2 and mouth attachment member 8> In this embodiment, the mouth attachment member 8 is configured to be attached to the mouth 5 by a stoppering method, but may also be configured to be attached to the mouth 5 by a screw method. In this embodiment, the circumferential engagement portion 4mb is disposed at a position farther from the opening end 5c of the mouth 5 than the axial engagement portion 4ma, but may also be disposed at a position closer to the opening end 5c of the mouth 5 than the axial engagement portion 4ma.

[0122] <Detailed Structure of Mouth Attachment Member 8> The mouth attachment member 8 will be described in detail using Figures 27 to 31. The mouth attachment member 8 is engaged with the inner bag 4 in the axial direction. Therefore, by pulling the mouth attachment member 8, the inner bag 4 can be pulled out. As shown in Figure 28, the mouth attachment member 8 preferably has a discharge port 8d for discharging the contents of the inner bag 4. In addition, the mouth attachment member 8 preferably has a nozzle 8c.

[0123] The spout-mounted member 8 includes a main body member 41 and an opening / closing member 42. When the spout-mounted member 8 is a cap 8a, the main body member 41 is the cap main body, and the opening / closing member 42 is an overcap. The main body member 41 is axially engaged with the inner bag 4 and includes a discharge port 8d that communicates with the interior of the inner bag 4. The opening / closing member 42 is configured to be able to open and close the discharge port 8d. FIG. 27 shows a closed state in which the discharge port 8d is closed. The opening / closing member 42 can be removed from the main body member 41 to set the discharge port 8d to an open state in which it is open. In this embodiment, the main body member 41 and the opening / closing member 42 are not connected to each other, but they may also be connected to each other by a hinge. The opening / closing member 42 is preferably engageable with the main body member 41 by an engagement structure such as a screw or a snap fit.

[0124] As shown in FIG. 28 , the main body member 41 includes an outer tube 41a, an inner tube 41b, a nozzle 8c, and an upper wall 41d. The inner tube 41b is disposed inside the outer tube 41a. The outer tube 41a and the inner tube 41b are connected via the upper wall 41d. The nozzle 8c is disposed above the upper wall 41d. A flow hole 41i is provided in the upper wall 41d, and the flow passage between the inner tube 41b and the nozzle 8c is connected through the flow hole 41i. Preferably, the flow hole 41i is sealed with a blocking member (not shown) before use. Upon use, the blocking member is removed to allow the contents to flow through the flow hole 41i. The tip of the nozzle 8c forms the discharge port 8d. The inner tube 41b is inserted into the protruding portion 4c and tightly contacts the inner surface 4f1 of the cylindrical seal portion 4f. As a result, the inner tube 41b and the cylindrical seal portion 4f are frictionally engaged in the circumferential direction. An engagement portion 8b is provided on the inner peripheral surface of the outer tube 41a. Preferably, an anti-slip shape is provided on the outer peripheral surface 41j of the outer tube 41a. In this case, it becomes easier to rotate the main body member 41 by gripping the outer peripheral surface 41j, and it is therefore possible to prevent the opening / closing member 42 from rotating without rotating the main body member 41 when pulling out the inner bag 4 while rotating it. Methods for providing an anti-slip shape include forming a knurled shape on the outer peripheral surface 41j, roughening the outer peripheral surface 41j, or making the outer peripheral surface 41j polygonal in plan view (e.g., hexagonal to dodecagonal).

[0125] The opening / closing member 42 comprises an outer tube 42a, an inner tube 42b, and an upper wall 42d. The outer tube 42a forms the outer peripheral surface of the opening / closing member 42. The inner tube 42b is disposed inside the outer tube 42a. The outer tube 42a and the inner tube 42b are connected via the upper wall 42d. The upper wall 42d does not have a discharge port for discharging the contents of the inner bag 4.

[0126] When the discharge port 8d is closed by the opening / closing member 42, the inner tube 42b is inserted into the nozzle 8c of the main body member 41 and is in close contact with the inner surface of the nozzle 8c. The bottom surface of the outer tube 42a abuts against the upper wall 41d of the main body member 41. From this state, by gripping the outer tube 42a and applying an upward force to the opening / closing member 42, the opening / closing member 42 can be separated from the main body member 41 to open the discharge port 8d.

[0127] As shown in Figures 28 to 31, the opening / closing member 42 is provided with an easy-to-open portion 50 having a structure that makes it easier to form an opening 51 that communicates with the interior of the inner bag 4. Examples of structures that make up the easy-to-open portion 50 include a structure that tears the weakened portion 8e and a structure that removes a lid that closes the opening 51. The opening 51 is preferably formed in the easy-to-open portion 50 without using any tools or with utensils used in eating (chopsticks or a straw). It is also preferable that the opening 51 is formed without using any power other than human power. The weakened portion 8e is a weakened portion that is made easier to tear, and can be formed by thinning the material or using a material with low rigidity.

[0128] 29 to 31 , in this embodiment, the easy opening forming portion 50 includes a weakened portion 8e provided on the opening / closing member 42 and a protrusion 8f provided adjacent to the weakened portion 8e. The underside of the protrusion 8f is a cavity 53. The easy opening forming portion 50 is configured so that when the protrusion 8f is tilted down, the weakened portion 8e is torn, thereby connecting the cavity 53 to the outside, thereby forming an opening 51. With this configuration, the opening 51 can be formed by tilting the protrusion 8f with a finger or the like.

[0129] More specifically, a recess 42e is provided in the upper wall 42d of the opening / closing member 42, and the weakened portion 8e and protrusion 8f are disposed within the recess 42e. The recess 42e is deep enough that the protrusion 8f does not protrude from the recess 42e. This prevents the protrusion 8f from getting in the way when the double container 1 is in use. To prevent the protrusion 8f from accidentally being knocked over when the double container 1 is in use, a protective seal 52 covering the recess 42e may be provided, as shown in FIG. 28 . The protrusion 8f can be knocked down after the protective seal 52 is removed. Alternatively, as shown in FIGS. 29 and 30 , a recess 42f may be provided surrounding the recess 42e. The recess 42f is shallower than the recess 42e, allowing the protective seal 52 to be disposed within the recess 42f. This makes it difficult for fingers to touch the edge of the protective seal 52, thereby preventing the protective seal 52 from being accidentally removed. The depth of the recess 42f is preferably equal to the thickness of the protective seal 52. In this case, the upper surface of the protective seal 52 and the upper surface around the recess 42f are flush with each other.

[0130] As shown in Figures 29 and 30, the bottom surface of the protrusion 8f is rectangular with rounded corners, and the weakened portion 8e is provided to surround three sides of the protrusion 8f. The remaining side without the weakened portion 8e serves as a hinge portion 8g, allowing the protrusion 8f to be folded down and tear the weakened portion 8e to form an opening 51. The weakened portion 8e may have any tearable thickness, e.g., 0.5 mm or less, preferably 0.3 mm or less. This thickness may be, for example, 0.01 to 0.5 mm, specifically, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, or 0.5 mm, or may be in a range between any two of the values ​​exemplified here. The weakened portion 8e is preferably formed by providing a groove 8h around the periphery of the protrusion 8f.

[0131] <Removal of inner bag 4> The mouth attachment member 8 is engaged with the mouth 5 of the inner bag 4 in the circumferential and axial directions, and is configured so that the inner bag 4 rotates relative to the outer shell 3 as the mouth attachment member 8 rotates. The cam mechanism 31 provided between the inner bag 4 and the outer shell 3 causes the inner bag 4 to move in a direction that pulls it out of the container body 2 as the inner bag 4 rotates.

[0132] With this configuration, by rotating the mouth attachment member 8, the inner bag 4 can be twisted and moved in a direction that allows it to come out of the container body 2, and then by pulling the mouth attachment member 8, the inner bag 4 can be pulled out of the container body 2.

[0133] Before pulling out the inner bag 4, the easy-opening forming section 50 forms an opening 51 in the mouth attachment member 8 that communicates with the interior of the inner bag 4, thereby preventing air inside the inner bag 4 from making it difficult to pull out the inner bag 4. When pulling out the inner bag 4, it is not essential to rotate the inner bag 4 relative to the outer shell 3; the inner bag 4 may be pulled out of the container body 2 by pulling it axially without rotating it relative to the outer shell 3. In this case, the mouth attachment member 8 only needs to be engaged with the inner bag 4 in the axial direction, and does not have to be engaged with it in the circumferential direction.

[0134] 2. Second Embodiment A second embodiment of the present invention will be described using Figures 32 and 33. This embodiment is similar to the first embodiment, and the contents described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs mainly from the first embodiment in the structure of the opening / closing member 42. The following description will focus on these differences.

[0135] In this embodiment, as shown in Figures 32 and 33, the easy opening forming portion 50 includes a weakened portion 8e provided on the opening / closing member 42 and a protrusion 8f provided adjacent to the weakened portion 8e. A cavity 53 is formed below the protrusion 8f. The easy opening forming portion 50 is configured so that the weakened portion 8e can be torn when the protrusion 8f is pushed into the cavity 53, thereby forming the opening 51. With this configuration, the opening 51 can be formed by pressing the protrusion 8f with a finger or the like.

[0136] In this embodiment, the weakened portion 8e and the protrusion 8f are also disposed in a recess 42e provided in the upper wall 42d. Since the protrusion 8f in this embodiment can be made lower than in the first embodiment, the recess 42e can also be made shallower than in the first embodiment.

[0137] As shown in Fig. 32, the bottom surface of the protrusion 8f is circular, with a hinge portion 8g provided on a portion of the outer periphery of the protrusion 8f and a weakened portion 8e provided in a portion other than the hinge portion 8g. When the protrusion 8f is pressed, the protrusion 8f rotates around the hinge portion 8g, tearing the weakened portion 8e and forming an opening 51. Preferably, as shown in Fig. 33A, the hinge portion 8g is thicker than the weakened portion 8e, and both the outer and inner surfaces of the hinge portion 8g are curved.

[0138] 3. Third Embodiment A third embodiment of the present invention will be described using Figures 34 and 35. This embodiment is similar to the first and second embodiments, and the contents described in the first and second embodiments can also be applied to this embodiment as long as they do not contradict the spirit of the first and second embodiments. This embodiment differs mainly from the first and second embodiments in the structure of the opening / closing member 42. The following description will focus on these differences.

[0139] In this embodiment, as shown in Figures 34 and 35, the opening-facilitating forming portion 50 includes a pressing portion 8i provided on the opening / closing member 42. A cavity 53 is formed below the pressing portion 8i. The pressing portion 8i is provided adjacent to the weakened portion 8e. The opening-facilitating forming portion 50 is configured so that the opening 51 can be formed by pressing the tip 54a of the opening tool 54 against the pressing portion 8i and forcing the opening tool 54 into the cavity 53, thereby tearing the weakened portion 8e. As the opening tool 54, any tool that can form the opening 51 by manually pressing the pressing portion 8i can be used, and it is preferable to use, for example, a tool used for eating (chopsticks or a straw).

[0140] The pressing portion 8i is disposed in a recess 42e provided in the upper wall 42d. Unlike the protrusion 8f, the pressing portion 8i does not need to protrude upward, so the recess 42e can be made shallower than in the first and second embodiments.

[0141] 34, the pressing portion 8i is circular, with a hinge portion 8g provided on a portion of the outer periphery of the pressing portion 8i and a weakened portion 8e provided in a portion other than the hinge portion 8g. The weakened portion 8e is preferably formed by providing a groove 8h around the periphery of the pressing portion 8i. When the tip 54a of the opening tool 54 presses the pressing portion 8i, the pressing portion 8i rotates around the hinge portion 8g, tearing the weakened portion 8e and forming the opening 51.

[0142] In a modification of the third embodiment, the pressing portion 8i is configured with a weakened portion 8e, as shown in Fig. 36. In this case, when the pressing portion 8i is pressed with the tip 54a of the opening tool 54, the weakened portion 8e is torn and the opening 51 is formed.

[0143] 4. Fourth Embodiment A fourth embodiment of the present invention will be described using Figures 37 to 41. This embodiment is similar to the first embodiment, and the contents described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs mainly from the first embodiment in the structure of the opening / closing member 42. The following description will focus on these differences.

[0144] 37 to 41, in this embodiment, the easy opening forming part 50 includes a lid part 8j provided on the opening / closing member 42. As shown in Fig. 40, the lid part 8j is connected to a peripheral wall of a cavity 53 provided on the underside of the lid part 8j at a connecting part 8k. As shown in Fig. 41, the easy opening forming part 50 is configured so that the connecting part 8k can be torn by gripping and pulling up a gripping part 8l provided on the lid part 8j, thereby exposing the cavity 53 and forming an opening 51.

[0145] As shown in Figures 38 and 39, the connecting portion 8k includes an annular portion 8k1 provided on the edge of the cavity 53 and a linear portion 8k2 connected to the annular portion 8k1. The linear portion 8k2 is preferably linear. The annular portion 8k1 is preferably provided between a pair of linear portions 8k2. In this case, tearing initiated at the end of the linear portion 8k2 can be transmitted to the annular portion 8k1, tearing the annular portion 8k1. The connecting portion 8k includes a tear stop portion 8k3 having a line width wider than the annular portion 8k1 and the linear portion 8k2. Tearing initiated at one end 8k4 of the linear portion 8k2 progresses through the annular portion 8k1 and stops at the tear stop portion 8k3. This prevents the cover portion 8j from being separated from the upper wall 42d.

[0146] As shown in Figures 38 and 40, a base 8m is preferably provided on the upper wall 42d, and a connecting portion 8k is provided between the base 8m and the lid portion 8j. The base 8m has an inclined surface 8m1 that is inclined so that the width of the base 8m narrows toward the connecting portion 8k. The inclined surface 8m1 and the lower surface 8j3 of the lid portion 8j intersect at an acute angle. Therefore, when a peeling force is applied to the lid portion 8j, tearing of the connecting portion 8k is likely to begin at the intersection of the inclined surface 8m1 and the lower surface 8j3.

[0147] 39 and 41, the end of the lid portion 8j on the side of one end 8k4 of the linear portion 8k2 is not connected to the base 8m, and this end serves as a grip portion 81. The distance between the lid portion 8j and the upper wall 42d widens toward one end 8j1 of the lid portion 8j at the grip portion 81, making it easier to grip the grip portion 8l.

[0148] 5. Fifth Embodiment A fifth embodiment of the present invention will be described using Figure 42. This embodiment is similar to the first embodiment, and the contents described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs mainly from the first embodiment in the structure of the mouth-mounted member 8. The following description will focus on these differences.

[0149] In the first embodiment, the outer tube 41a of the main body member 41 and the outer tube 42a of the opening / closing member 42 have the same diameter, and there is no step between them. While this configuration is preferable from the standpoint of appearance, there is a problem in that when rotating the mouth attachment member 8 to remove the inner bag 4, the main body member 41 and the opening / closing member 42 should be rotated together, but the opening / closing member 42 may be rotated by mistake. To prevent this problem from occurring, in this embodiment, the diameter of the outer tube 41a of the main body member 41 is made larger than the diameter of the outer tube 42a of the opening / closing member 42. In this case, the main body member 41 is provided with an exposed portion 41a2 that is not covered by the lower end 42a1 of the outer tube 42a and is exposed to the outside. With this configuration, when the mouth attachment member 8 is pinched with fingers to rotate it, the pressure with which the fingers press against the outer tube 41a of the main body member 41 increases. This makes it easier for the main body member 41 to rotate when attempting to rotate the mouth attachment member 8, thereby preventing the above problem from occurring. As explained in the first embodiment, it is preferable to provide a non-slip shape on the outer peripheral surface 41j of the outer cylinder 41a of the main body member 41. In this case, the main body member 41 can be rotated more easily.

[0150] 6. Sixth Embodiment A sixth embodiment of the present invention will be described using Figures 43 and 44. This embodiment is similar to the fifth embodiment, and the details described in the fifth embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the fifth embodiment. This embodiment differs mainly from the fifth embodiment in the structure of the mouth-mounted member 8. The following description will focus on these differences.

[0151] In the fifth embodiment, the exposed portion 41a2 was formed by expanding the diameter of the outer tube 41a of the main body member 41. However, in this embodiment, the shape of the main body member 41 is not changed, and the exposed portion 41a2 is formed by reducing the diameter of the outer periphery of the lower end 42a1 of the outer tube 42a of the open-close member 42. In the exposed portion 41a2, the main body member 41 is not covered by the lower end 42a1. In the exposed portion 41a2, a step is provided between the main body member 41 and the open-close member 42. In this embodiment, multiple (eight in this embodiment) reduced-diameter portions 42a2 are intermittently provided on the lower end 42a1, but the reduced-diameter portions 42a2 may be provided around the entire circumference of the lower end 42a1. In this embodiment, the reduced-diameter portions 42a2 are formed by reducing the thickness of the outer tube 42a. However, the outer tube 42a may protrude inward by the depth of the reduced-diameter portions 42a2 without changing the wall thickness. In this embodiment, the same effect as in the fifth embodiment can be achieved to prevent the problem of accidentally rotating only the opening / closing member 42. The reduced diameter portion 42a2 may extend to the upper end of the outer tube 42a. In the invention from the viewpoint of providing the exposed portion 41a2, it is not essential to provide the opening-facilitating portion 50 on the opening / closing member 42.

[0152] 7. Seventh Embodiment A seventh embodiment of the present invention will be described using Figures 45 and 46. This embodiment is similar to the sixth embodiment, and the details described in the sixth embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the sixth embodiment. This embodiment differs mainly from the sixth embodiment in the structure of the mouth-mounted member 8. The following description will focus on these differences.

[0153] In the sixth embodiment, the exposed portion 41a2 was formed by reducing the diameter of the outer periphery of the lower end 42a1 of the outer tube 42a of the open-close member 42. However, in this embodiment, the exposed portion 41a2 is formed by providing a notched portion 42a3 in the lower end 42a1. At the exposed portion 41a2, the main body member 41 is not covered by the lower end 42a1. In this embodiment, a plurality of notched portions 42a3 (eight in this embodiment) are provided intermittently in the lower end 42a1, but the reduced diameter portion 42a2 may be provided around the entire circumference of the lower end 42a1. This embodiment also achieves the same effect as the fifth embodiment, thereby preventing the problem of accidentally rotating only the open-close member 42.

[0154] 1: Double container, 2: Container main body, 2a: Maximum circumference, 2a1: Part, 2a2: Part, 2b: Minimum circumference, 3: Outer shell, 3a: Open end, 3a1: Base surface, 3a2: Annular convex part, 3a3: Inner bag support surface, 3a4: Vertex, 3f1: First flange, 3f2: Second flange, 3f3: Bottom surface, 3f4: center surface, 3f5: upper surface, 3g: recess, 3l: cam rail, 3m: grooved strip, 4: inner bag, 4a: first cylinder, 4b: second cylinder, 4b1: peripheral wall, 4b2: lower wall, 4b3: corner, 4b4: lower surface, 4c: protrusion, 4c1: protruding tube, 4c10: flange, 4c11: lower surface, 4c12: outer peripheral surface, 4c13: recess, 4c14: upper surface, 4c2: engaging protrusion, 4c5: annular protrusion, 4c8: tapered surface, 4c9: male thread portion, 4d: inner bag main body, 4e: inclined portion, 4f: sealing cylinder portion, 4f1: inner surface, 4g: ridge, 4i: uneven portion, 4i1: recess, 4i2: protrusion, 4m3: lower surface, 4ma: axial engaging portion, 4mb: circumferential engaging portion, 4o: enlarged diameter portion, 5: mouth portion, 5b: flange, 5b1: outer circumferential surface, 5c: opening end, 6: body portion, 6b: shoulder portion, 6c: body main body, 6d: inwardly convex curved portion, 6e: outwardly convex curved portion, 6f: boundary portion, 7: bottom, 7a: bottom surface, 8: mouth portion attachment member, 8a: cap, 8b: Engagement portion, 8b1: ​​female screw portion, 8b3: annular convex portion, 8b4: tip, 8c: nozzle, 8d: discharge port, 8e: weakened portion, 8f: protrusion, 8g: hinge portion, 8h: groove, 8i: pressing portion, 8j: lid portion, 8j1: one end, 8j3: lower surface, 8k: connecting portion, 8k1: annular portion, 8k2: linear portion, 8k3: tear stop portion, 8k4: one end, 8l: gripping portion, 8m: base, 8m1: inclined surface, 9: pump, 9a: cylindrical portion, 9a1: threaded cylindrical portion, 9a2: top surface portion, 9a3: sliding cylindrical portion, 9a4: lower end, 9b: nozzle, 9c: piston portion, 9d: pump mechanism portion, 9e: tube, 9f: head, 9f1: cylindrical portion, 9g: flange, 11: container, 13: outer preform, 13a: mouth, 13b: body, 13c: bottom, 13d: open end, 13f2: second flange, 13f3: lower surface, 13l: cam rail, 14: inner preform, 14a: mouth, 14b: body, 14c: bottom, 14c2: engagement convex part, 14c21: engaging convex part, 14c22: engaging convex part, 14c23: engaging convex part, 14c24: engaging convex part, 14g: convex stripe, 15: preform, 15a: mouth part, 15b: body part, 15c: bottom part, 15g: cam mechanism, 31: cam mechanism, 41: main body member, 41a: outer cylinder, 41a1: opening end,41a2: exposed portion, 41b: inner cylinder, 41b1: outer peripheral surface, 41d: upper wall, 41i: flow hole, 41j: outer peripheral surface, 42: opening / closing member, 42a: outer cylinder, 42a1: lower end, 42a2: reduced diameter portion, 42a3: missing portion, 42b: inner cylinder, 42d: upper wall, 42e: recess, 42f: recess, 43: hinge, 44: gap, 45: engaging member, 45a: opening, 45b: peripheral surface, 45c : uneven portion, 45c1: recess, 45c2: protrusion, 45d: cylindrical portion, 45d1: outer peripheral surface, 45e: top surface, 45g: upper surface, 45h: opening end, 46: sealing member, 46a: opening, 47: circumferential engagement portion, 50: easy opening forming portion, 51: opening, 52: protective seal, 53: cavity, 54: opening tool, 54a: tip, C: central axis, PL: parting line, α: angle,

Claims

1. A container comprising a container body and a mouth attachment member attached to the mouth of the container body, wherein the mouth attachment member is configured to be attached to the mouth in a stoppered manner, the container body comprising an axial engagement portion that engages with the mouth attachment member in the axial direction and a circumferential engagement portion that engages with the mouth attachment member in the circumferential direction, the axial direction is the direction in which a central axis of the mouth extends and the circumferential direction is a rotational direction about the central axis, the circumferential engagement portion is positioned at a position farther from the open end of the mouth than the axial engagement portion, the mouth attachment member comprising an engagement portion, and the engagement portion of the mouth attachment member engages with the axial engagement portion in the axial direction and engages with the circumferential engagement portion in the circumferential direction.

2. A container according to claim 1, wherein said circumferential engaging portion comprises a plurality of engaging protrusions spaced apart along said circumferential direction.

3. A container according to claim 1, wherein the axial engagement portion comprises an annular protrusion.

4. A container as described in claim 1, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the inner bag has a protrusion protruding from the open end of the outer shell, and the axial engagement portion and the circumferential engagement portion are provided on the protrusion.

5. A container according to any one of claims 1 to 4, wherein the mouth attachment member comprises an outer tube, and the engagement portion is provided on the inner peripheral surface of the outer tube.

6. A method for manufacturing a container according to any one of claims 1 to 4, wherein the container body is manufactured by biaxially stretching and blow molding a preform.

7. A double container comprising a container body, an engaging member, and a mouth attachment member, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the inner bag has a protrusion protruding from the open end of the outer shell, the mouth attachment member is attached to the protrusion, and the engaging member and the protrusion are engaged circumferentially at a circumferential engagement portion.

8. A double container as described in claim 7, wherein the container body is configured such that, when viewed from above the double container, the inner bag is rotated in one direction relative to the outer shell so that the inner bag is displaced in a direction that causes it to slip out of the container body.

9. A double container according to claim 8, wherein the mouth attachment member and the protrusion are screwed together such that rotation of the mouth attachment member relative to the protrusion in the one direction is a direction for loosening the screwing.

10. A double container according to any one of claims 7 to 9, wherein the engaging member and the protrusion are engaged in a concave-convex manner in the circumferential direction at the circumferential engaging portion.

11. A double container as claimed in any one of claims 7 to 9, wherein the protrusion is provided with a male thread portion, the inner bag is provided with a flange, the lower surface of the flange abuts against the outer shell, and the circumferential engagement portion is disposed between the male thread portion and the flange.

12. A double container according to any one of claims 7 to 9, wherein the protrusion is disposed within an opening provided in the engaging member.

13. A double container as described in claim 12, wherein the engaging member comprises a cylindrical portion and a top surface portion provided on the top surface of the cylindrical portion, the opening is provided on the top surface portion, and the peripheral surface of the opening and the outer circumferential surface of the protrusion are engaged in the circumferential direction.

14. A double container as described in claim 13, wherein the protrusion is provided with a male thread portion, the inner bag is provided with a flange, the lower surface of the flange abuts against the outer shell, the circumferential engagement portion is disposed between the male thread portion and the flange, the upper surface of the flange abuts against the top surface portion, and the tubular portion of the engagement member is disposed so as to surround the outer shell.

15. A double container comprising a container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, and the inner bag is configured to be removable from the container body, the container body comprises a mouth, a body and a bottom, the mouth being a tubular portion having an open end, the body being arranged adjacent to the mouth on a side farther from the open end than the mouth, and the bottom being configured to close the lower end of the body, wherein the direction in which the central axis of the mouth of the container body extends is defined as the axial direction, the total height of the container body is defined as H, the portion of the body having the greatest perimeter in a cross section perpendicular to the axial direction is defined as a maximum perimeter portion, and the height of the maximum perimeter portion from the bottom surface of the container body is defined as Hmax, the body comprises a shoulder portion configured such that the perimeter in a cross section perpendicular to the axial direction increases with increasing distance from the mouth, and Hmax / H is 0.20 to 0.40, The double container has an outer diameter in the major axis direction at which the outer diameter is maximum at the maximum circumferential length portion as DLmax, and an outer diameter in the minor axis direction perpendicular to the major axis direction as DSmax, in which DSmax / DLmax is 0.70 to 0.

95.

16. A double container as claimed in claim 15, wherein the part of the body which has the smallest perimeter in a cross section perpendicular to the axial direction is defined as a minimum perimeter part, the height of the minimum perimeter part from the bottom surface of the container body is defined as Hmin, and the outer diameter in the major axis direction at the minimum perimeter part is defined as DLmin, where (DLmax-DLmin) / (Hmin-Hmax) is 0.26 to 0.

46.

17. The double container according to claim 16, wherein Hmin / H is 0.80 to 0.

90.

18. A double container according to any one of claims 15 to 17, wherein the body portion has an inner convex curved portion that is convex inward and an outer convex curved portion that is convex outward, the outer convex curved portion being disposed closer to the bottom surface than the inner convex curved portion, the maximum circumference portion being disposed on the outer convex curved portion, and wherein, where Hb is the height from the bottom surface of the boundary portion between the inner convex curved portion and the outer convex curved portion and DLb is the outer diameter in the major axis direction at the boundary portion, (DLmax-DLb) / (Hb-Hmax) is 0.28 to 0.

48.

19. The dual container according to claim 18, wherein Hb / H is 0.45 to 0.

75.

20. A double container comprising a container body and a mouth attachment member attached to the mouth of the container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, and when the direction in which the central axis of the mouth of the container body extends is defined as the axial direction, the mouth attachment member comprises a main body member and an opening and closing member, the main body member engages with the inner bag in the axial direction and has a discharge outlet communicating with the inside of the inner bag, the opening and closing member is configured to be able to open and close the discharge outlet, and the opening and closing member is provided with an easy-to-open opening forming portion having a structure that makes it easy to form an opening communicating with the inside of the inner bag.

21. A double container as described in claim 20, wherein the opening / closing member has an outer tube that forms the outer peripheral surface of the opening / closing member, and the main body member has an exposed portion that is not covered by the lower end of the outer tube and is exposed to the outside.

22. A double container as described in claim 20 or claim 21, wherein the easy-to-open forming portion comprises a weakened portion provided on the opening / closing member and a protrusion provided adjacent to the weakened portion, a cavity is provided below the protrusion, and the easy-to-open forming portion is configured to be able to form the opening by tearing the weakened portion and connecting the cavity to the outside when the protrusion is tilted down.

23. A double container as described in claim 20 or claim 21, wherein the easy-to-open forming portion comprises a weakened portion provided on the opening / closing member and a protrusion provided adjacent to the weakened portion, a cavity is provided below the protrusion, and the easy-to-open forming portion is configured to tear the weakened portion and form the opening when the protrusion is pushed into the cavity.

24. A double container as described in claim 20 or claim 21, wherein the easy-to-open opening forming portion comprises a pressing portion provided on the opening / closing member, a cavity is provided below the pressing portion, the pressing portion is composed of a weakened portion or is provided adjacent to a weakened portion, and the easy-to-open opening forming portion is configured so that the opening can be formed by tearing the weakened portion by pressing a tip of an opening tool against the pressing portion and forcing the opening tool into the cavity.

25. A double container as described in claim 20 or claim 21, wherein the easy-to-open forming portion comprises a lid portion provided on the opening / closing member, the lid portion is connected to a connecting portion at a peripheral wall of a cavity provided on the underside of the lid portion, and the easy-to-open forming portion is configured to be able to form the opening by gripping and pulling up a gripping portion provided on the lid portion to tear the connecting portion and expose the cavity.

26. A double container comprising a container body and a mouth attachment member attached to the mouth of the container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, and when the direction in which the central axis of the mouth of the container body extends is defined as the axial direction, the mouth attachment member comprises a main body member and an opening and closing member, the main body member engages with the inner bag in the axial direction and has a discharge port communicating with the inside of the inner bag, the opening and closing member is configured to be able to open and close the discharge port, the opening and closing member comprises an outer tube that forms the outer peripheral surface of the opening and closing member, and the main body member has an exposed portion that is not covered by the lower end of the outer tube and is exposed to the outside.

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