Double container and method of pulling out inner bag

Abstract

To provide a double container which enables an inner bag to be easily pulled out from an outer shell.SOLUTION: According to the invention, a double container includes a container body having an inner bag and an outer shell. The container body is a biaxial orientation blow-molded item. The inner bag and the outer shell are interlocked in an axial direction at a mouth part of the container body. The double container of the invention is excellent in recyclability and thus can be preferably used for manufacturing of a recycled material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a double-layered container and a method for removing the inner bag. [Background technology]

[0002] Conventionally, double-layered containers having a container body with an outer shell and an inner bag have been known. For example, Patent Document 1 discloses a double-layered container formed by biaxially stretching blow molding an outer shell preform and an inner bag preform in a stacked state. [Prior art documents] [Patent documents]

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

[0004] However, when the outer shell and inner bag of such a double container are 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.

[0005] The outer shell and the inner bag are expected to be separated by pulling the inner bag out of the outer shell, and it is desirable to make it easier to pull the inner bag out of the outer shell.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a double-layered container in which the inner bag can be easily pulled out from the outer shell. [Means for solving the problem]

[0007] According to the present invention, the following inventions are provided. [1] A double container comprising a container body having an inner bag and an outer shell, wherein the container body is a biaxially stretched blow molded body, and the inner bag and the outer shell are axially engaged with each other at the mouth of the container body. [2] The double container according to [1], wherein the recessed and projecting engagement is configured to be releasable by relative rotation of the inner bag and the outer shell. [3] A double container according to [1] or [2], wherein the concave-convex engagement is constituted by a convex portion provided on the outer peripheral surface of the inner bag and a concave portion provided on the inner peripheral surface of the outer shell. [4] A double container as described in [1] or [2], wherein the container body has a mouth and a shoulder, the shoulder being a portion whose outer diameter increases as it moves away from the mouth, and the inner bag and the outer shell abutting at the shoulder. [5] A double container according to [4], wherein the outer surface of the inner bag and the inner surface of the outer shell have the same inclination angle at the shoulder portion. [6] A double container according to [1] or [2], comprising a stopper-type mouth attachment member that is attached to the mouth of the container body. [7] A double container as described in [1] or [2], wherein the inner bag and the mouth attachment member each have a plurality of engaging protrusions spaced apart in the circumferential direction, and the inner bag and the mouth attachment member engage with each other in the circumferential direction by engaging the engaging protrusions of the inner bag with the engaging protrusions of the mouth attachment member. [8] A double container as described in [1] or [2], comprising a mouth attachment member attached to the mouth of the container body, and the inner bag is configured to rotate in accordance with the rotation of the mouth attachment member. [9] A double container according to [1] or [2], wherein the inner bag has a cylindrical shape in the entire portion facing the mouth of the outer shell.

[10] A double container according to [1] or [2], configured so that the inner bag does not shrink when the contents of the inner bag are discharged.

[11] A method for removing an inner bag from a double container according to [1] or [2], comprising a step of directly gripping the inner bag and rotating the inner bag. [Effects of the Invention]

[0008] In the container body of the double-layered container of the present invention, the inner bag and the outer shell are axially engaged with each other at the opening of the container body through a concave-convex structure. This container body is formed by biaxially stretching blow molding a preform consisting of an inner preform and an outer preform that are axially engaged with each other through a concave-convex structure. In this case, there is no need to tightly fit the outer preform and the inner preform to prevent the outer preform from falling out of the inner preform, and even in the container body obtained by biaxial stretching blow molding, the outer shell and the inner bag are not tightly fitted together. Therefore, by releasing the concave-convex engagement between the inner bag and the outer shell, the inner bag can be easily pulled out from the outer shell. [Brief explanation of the drawings]

[0009] [Figure 1] This is a perspective view of the double container 1 of the first embodiment of the present invention, showing the state in which the spout attachment member 8 is separated from the container body 2. The dashed dotted line in the figure indicates the boundary line where the curvature of the faces that make up the surface shape changes. The same applies to the other figures. [Figure 2] FIG. 2 is an enlarged view of region B in FIG. [Figure 3] 2 is a cross-sectional view taken along a plane passing through the central axis of the mouth portion 5 of the container body 2 and perpendicular to the opening surface 5c1. [Figure 4] FIG. 2 is an exploded perspective view of the container body 2. [Figure 5] FIG. [Figure 6] FIG. 6A is a perspective view of the mouth-mounted member 8 with a portion cut away, and FIG. 6B is a perspective view of the mouth-mounted member 8 as seen obliquely from below. [Figure 7] FIG. 2 is a front view of the spout-mounted member 8 mounted on the container body 2. [Figure 8] 8A and 8B are end views taken along planes A and B in FIG. 7, respectively. [Figure 9] FIG. 2 is a perspective view showing a state in which the inner preform 14 and the outer preform 13 are separated. [Figure 10]FIG. 1 is a perspective view of a preform 15 formed by covering an outer preform 13 on an inner preform 14. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes embodiments of the present invention. The various features shown in the following embodiments can be combined with each other. Furthermore, each feature can be an independent invention.

[0011] 1. First embodiment 1-1. Structure of double container 1 <Basic configuration> As shown in FIG. 1, the double container 1 of the first embodiment of the present invention comprises a container body 2 and a spout attachment member 8.

[0012] As shown in Figures 1 and 2, 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 mouth 5 has an engagement portion 5a to which a mouth attachment member 8 such as a cap or a pump can be attached. In this embodiment, the mouth attachment member 8 is of a stopper type, and therefore the engagement portion 5a is an annular protrusion 5a2 that protrudes in the circumferential direction. The mouth attachment member 8 may or may not have a check valve (not shown). The mouth 5 is provided with a flange 5b. The flange 5b can be used to support the mouth 5 when the mouth attachment member 8 is attached to the mouth 5.

[0013] The body 6 is disposed adjacent to the mouth 5 on the 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 circumscribed circle diameter if 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 with a substantially constant outer diameter, located closer to the bottom 7 than the shoulder 6b.

[0014] As shown in Fig. 3, the container body 2 includes an inner bag 4 and an outer shell 3 arranged to cover the inner bag 4. The inner bag 4 is housed within the outer shell 3 except for the protruding portion 4c. 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.

[0015] The thickness of the outer shell 3 at the center in the height direction of the container body 2 is, for example, 0.2 to 0.8 mm, preferably 0.25 to 0.5 mm. Specific examples of this thickness include 0.2, 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.8 mm, and may be within a range between any two of the values ​​exemplified here. The thickness of the inner bag 4 at the center in the height direction of the container body 2 is, for example, 0.05 to 0.25 mm, preferably 0.08 to 0.20 mm. Specific examples of this thickness include 0.05, 0.08, 0.10, 0.15, 0.20, and 0.25 mm, and may be within a range between any two of the values ​​exemplified here.

[0016] If the mouth-attached member 8 is not provided with a check valve, the inner bag 4 does not shrink even after the contents of the inner bag 4 are expelled, making it difficult to pull out the inner bag 4 through the mouth 5 of the outer shell 3. Since the present invention makes it easy to pull out the inner bag 4 through the mouth 5 of the outer shell, the significance of applying the present invention is particularly evident when the mouth-attached member 8 is not provided with a check valve.

[0017] The inner diameter D2 of the mouth portion 5 of the outer shell 3 is, for example, 20 to 50 mm, and preferably 25 to 40 mm. The outer diameter D4 of the mouth portion 5 of the outer shell 3 (the outer diameter of the portion other than the engaging portion 5a and the flange 5b) is, for example, 25 to 55 mm, and preferably 30 to 45 mm. The inner diameter D2 is specifically, for example, 20, 25, 30, 35, 40, 45, or 50 mm, and the outer diameter D4 is specifically, for example, 25, 30, 35, 40, 45, 50, or 55 mm, and each may be within a range between any two of the numerical values ​​exemplified here. The length of the mouth portion 5 is, for example, 15 to 35 mm, and specifically, for example, 15, 20, 25, 30, or 35 mm, and may be within a range between any two of the numerical values ​​exemplified here.

[0018] <Engagement structure between the mouth attachment member 8 and the container body 2> The mouth attachment member 8 is preferably configured to be attachable to the mouth 5, and configured so that the inner bag 4 rotates at the mouth 5 as the mouth attachment member 8 rotates (here, relative rotation with respect to the outer shell 3). With this configuration, it is possible to rotate the inner bag 4 at the mouth 5 by rotating the mouth attachment member 8. In the container body 2 of this embodiment, by rotating the inner bag 4 relative to the outer shell 3, the inner bag 4 moves in a direction that pulls it out of the outer shell 3, so that by rotating the mouth attachment member 8, the inner bag 4 can be raised from the outer shell 3. Then, the raised portion of the inner bag 4 from the outer shell 3 can be used as a trigger to easily pull the inner bag 4 out of the outer shell 3.

[0019] Furthermore, since the body 6 of the container body 2 has a larger outer diameter than the mouth 5, it is not easy to pull the inner bag 4 out through the mouth 5 of the outer shell 3 simply by pulling the inner bag 4. However, by rotating the mouth 5 of the inner bag 4 and twisting the inner bag 4 to reduce the diameter of the body 6 of the inner bag 4, the body 6 of the inner bag 4 can more easily pass through the mouth 5 of the outer shell 3, and the inner bag 4 can be easily pulled out of the outer shell 3.

[0020] The engagement structure between the spout mounting member 8 and the container body 2 will be described in more detail below.

[0021] 4, inner bag 4 has a protruding portion 4c that protrudes from open end 3a of outer shell 3. Protruding portion 4c has a protruding tube 4c1, an engaging protrusion 4c2, and an abutting flange 4c4.

[0022] The engaging protrusions 4c2 protrude radially outward from the circumferential surface of the protruding tube 4c1. The engaging protrusions 4c2 are provided at multiple locations (eight locations in this embodiment) spaced apart in the circumferential direction. The engaging protrusions 4c2 have a tapered surface 4c3 on their upper surfaces. This makes it easier for the annular protrusion 28c (shown in FIG. 6A) of the nozzle attachment member 8 to climb over the engaging protrusions 4c2, as will be described later.

[0023] The abutment flange 4c4 is an annular portion that is positioned to abut against the open end 3a and has a larger diameter than the protruding tube 4c1. The abutment of the abutment flange 4c4 against the open end 3a prevents the inner bag 4 from falling out into the outer shell 3. Alternatively, the abutment flange 4c4 may not be provided, and the engagement protrusion 4c2 may be abutted against the open end 3a to prevent the inner bag 4 from falling out into the outer shell 3.

[0024] An annular protrusion 5a2 and engagement protrusions 3k intermittently provided on the annular protrusion 5a2 are provided on the outer peripheral surface of the mouth portion 5 of the outer shell 3. The engagement protrusions 3k are provided at multiple locations (eight locations in this embodiment) on the annular protrusion 5a2, spaced apart in the circumferential direction.

[0025] As shown in Figure 6, the mouth attachment member 18 is a plug-type, and can be attached to the mouth 5 by applying an axial force (a direction perpendicular to the opening surface 5c1 surrounded by the opening end 5c of the mouth 5) to the mouth attachment member 18.

[0026] The mouth attachment member 18 comprises a main body 28 and a band 29. The main body 28 and the band 29 are connected to each other via an easily tearable connecting portion 30. The band 29 engages with the mouth 5 of the outer shell 3 in the circumferential and axial directions. Therefore, the band 29 is restricted from moving in the circumferential and axial directions relative to the mouth 5 of the outer shell 3. The main body 28 engages with the mouth 5 of the inner bag 4 in the circumferential and axial directions. Therefore, the main body 28 is restricted from moving in the circumferential and axial directions relative to the mouth 5 of the inner bag 4.

[0027] The connecting portion 30 is configured so that it can be torn apart by applying a force (shear force, rotational force, etc.) between the main body portion 28 and the band portion 29. The connecting portion 30 is preferably thinner than the main body portion 28 and the band portion 29. The connecting portion 30 is preferably provided at multiple locations spaced apart in the circumferential direction, which makes it even easier to tear.

[0028] The band portion 29 is belt-shaped and is disposed so as to surround the annular protrusion 5a2. The inner peripheral surface of the band portion 29 is provided with an engaging protrusion 29a extending in the circumferential direction and an engaging recess 29b provided at a position closer to the connecting portion 30 than the engaging protrusion 29a. The engaging recesses 29b are provided at multiple locations (eight locations in this embodiment) spaced apart in the circumferential direction. The engaging protrusion 29a engages with the annular protrusion 5a2 in the axial direction, thereby causing the band portion 29 to engage with the opening portion 5 of the outer shell 3 in the axial direction. A tapered surface 29a1 is provided on the underside of the engaging protrusion 29a, which reduces the force required for the engaging protrusion 29a to overcome the annular protrusion 5a2.

[0029] 8B, the engagement projections 3k are housed in the engagement recesses 29b, whereby the band portion 29 circumferentially engages with the mouth portion 5 of the outer shell 3. As will be described later, the double container 1 of this embodiment is configured so that the mouth attachment member 18 and the inner bag 4 rotate together, causing the inner bag 4 to move in a direction that pulls it out of the outer shell 3. If the mouth attachment member 18 rotates unintentionally relative to the outer shell 3, there is a risk that the inner bag 4 will unintentionally pull out of the outer shell 3. To prevent this problem from occurring, the band portion 29 of the mouth attachment member 18 is engaged circumferentially with the mouth portion 5 of the outer shell 3, preventing the mouth attachment member 18 from rotating relative to the mouth portion 5 of the outer shell 3.

[0030] A notch 29c is provided in the band portion 29. By grasping one end of the band portion 29 at the notch 29c and pulling it radially outward, the connecting portion 30 is torn apart, and the band portion 29 can be removed. Note that a knob may be provided at one end of the band portion 29 to make it easier to grasp the one end of the band portion 29.

[0031] The main body 28 includes an outer cylinder 28a, an inner cylinder 28b, an annular projection 28c, an engaging projection 28d, a top plate 28e, and a discharge port 28f.

[0032] Top plate 28e is provided on the upper surface of outer cylinder 28a. Top plate 28e is provided with discharge port 28f. Discharge port 28f may be provided with a nozzle. Inner cylinder 28b has a smaller diameter than outer cylinder 28a and is a so-called inner ring that is disposed inside outer cylinder 28a.

[0033] Annular protrusion 28c is an annular protrusion provided on the inner peripheral surface of outer tube 28a so as to extend in the circumferential direction. Annular protrusion 28c engages with engaging protrusion 4c2 in the axial direction, thereby engaging main body 28 with opening 5 of inner bag 4 in the axial direction. Engaging protrusions 28d are provided at multiple locations (eight locations in this embodiment) spaced apart in the circumferential direction. As shown in FIG. 8A , engaging protrusions 28d are disposed between adjacent engaging protrusions 4c2, thereby engaging main body 28 with opening 5 of inner bag 4 in the circumferential direction.

[0034] <Engagement structure between outer shell 3 and inner bag 4> As shown in Figure 4, cam protrusions 4g and engagement protrusions 4h are provided on the outer peripheral surface of inner bag 4. Cam protrusions 4g and engagement protrusions 4h are connected to each other. The lower surfaces of cam protrusions 4g and engagement protrusions 4h are each inclined clockwise when viewed from the opening end 5c of mouth 5 so as to approach the opening end 5c.

[0035] As shown in FIG. 5, a cam rail 3l and an engagement recess 3m are provided on the inner peripheral surface of the outer shell 3. The engagement recess 3m is provided so that the lower surface of the engagement recess 3m is continuous with the upper surface of the cam rail 3l. The upper surface of the cam rail 3l and the lower surface of the engagement recess 3m are inclined clockwise when viewed from the opening end 3a so as to approach the opening end 3a. Before the inner bag 4 is pulled out of the outer shell 3, the engagement protrusion 4h is disposed within the engagement recess 3m, and the lower surface of the cam protrusion 4g abuts against the upper surface of the cam rail 3l. The cam protrusion 4g and the cam rail 3l form a cam mechanism 31. In this embodiment, the engagement recess 3m is a through hole, but it may also be a blind hole.

[0036] <How to remove inner bag 4> Before starting to pull out the inner bag 4, the main body 28 and band 29 of the mouth attachment member 18 are connected, and the band 29 is axially engaged with the mouth 5 of the outer shell 3, so in this state the inner bag 4 cannot be pulled out from the outer shell 3. For this reason, first, one end of the band 29 is grasped at the notch 29c and pulled radially outward to tear the connecting portion 30 and remove the band 29. This releases the engagement between the mouth attachment member 18 and the mouth 5 of the outer shell 3, making it possible to pull out the inner bag 4.

[0037] Next, the spout attachment member 18 is rotated clockwise as viewed from the opening end 5c. Because the inner bag 4 is circumferentially engaged with the spout attachment member 18, the inner bag 4 rotates in the same direction as the spout attachment member 18 rotates, and the cam projections 4g move along the cam rails 3l. This movement causes the inner bag 4 to move in a direction that removes it from the outer shell 3. At this time, the inner bag 4 is twisted, and the body portion 6 of the inner bag 4 is reduced in diameter. Note that, if an attempt is made to rotate the inner bag 4 counterclockwise as viewed from the opening end 5c, as shown in FIG. 8B, the cam projections 4g of the inner bag 4 interfere with the projections 3l1 that form the cam rails 3l, preventing the inner bag 4 from rotating. This prevents the inner bag 4 from being rotated in the wrong direction.

[0038] Thereafter, the mouth attachment member 18 is moved axially so as to pull the inner bag 4 out of the outer shell 3. Because the mouth attachment member 18 is axially engaged with the inner bag 4, the axial force applied to the mouth attachment member 18 is transmitted to the inner bag 4, causing the inner bag 4 to be pulled out of the outer shell 3. This pulling out is performed in a state where the inner bag 4 is raised above the outer shell 3, so the force required to pull out the inner bag 4 is reduced.

[0039] 1-2. Manufacturing method of double container 1 As shown in FIGS. 9 and 10, the container body 2 can be formed by heating a preform 15 and biaxially stretching and blow molding it.

[0040] <Configuration of inner preform 14, outer preform 13, and preform 15> For example, the preform 15 can be constructed by covering an inner preform 14 that will become the inner bag 4 with an outer preform 13 that will become the outer shell 3 .

[0041] As shown in Figure 9, the inner preform 14 is cylindrical with a bottom and includes a mouth portion 14a, a body portion 14b, and a bottom portion 14c. A protrusion 14d is provided at the open end of the mouth portion 14a. The protrusion 14d does not deform during molding and remains in its original shape to become the protrusion 4c. Therefore, the matters described for the protrusion 4c also apply to the protrusion 14d. The bottom portion 14c is provided so as to close the lower end of the body portion 14b. A positioning pin 14c1 is provided on the bottom portion 14c. The outer peripheral surface of the mouth portion 14a of the inner preform 14 is provided with a cam protrusion 14g and an engagement protrusion 14h that become the cam protrusion 4g and the engagement protrusion 4h.

[0042] As shown in Fig. 9, the outer preform 13 is cylindrical with a bottom and includes a mouth portion 13a, a body portion 13b, and a bottom portion 13c. The bottom portion 13c is provided so as to close the lower end of the body portion 13b. The bottom portion 13c is provided with an annular protrusion 13d and a positioning hole (not shown). The mouth portion 13a of the outer preform 13 is provided with a cam rail 13l that becomes the cam rail 3l and an engagement recess 13m that becomes the engagement recess 3m.

[0043] 10, when forming the preform 15, the protrusion 14d is brought into contact with the open end of the mouth portion 13a, and the positioning pin 14c1 is inserted into the positioning hole. This positions the inner preform 14 and the outer preform 13 relative to each other. In this state, the mouth portion 14a faces the mouth portion 13a, and the body portion 14b faces the body portion 13b.

[0044] The mouth portions 13a and 14a become the mouth portion 15a of the preform 15, the body portions 13b and 14b become the body portion 15b of the preform 15, and the bottom portions 13c and 14c become the bottom portion 15c of the preform 15. The body portion 15b and the bottom portion 15c are mainly stretched in the biaxial stretch blow molding.

[0045] <Engagement of the Concave and Convex Parts at the Mouth Portion 15a of the Inner Preform 14 and the Outer Preform 13> When the preform 15 is heated and biaxially stretched and blow-molded, the inner peripheral surface of the preform 15 (i.e., the inner peripheral surface of the inner preform 14) is usually supported. The preform 15 can be conveyed upright, with the bottom 15c facing downward, or inverted, with the bottom 15c facing upward. Upright conveyance is common and preferred. However, conveying the preform 15 upright can cause a problem in that the outer preform 13 becomes detached from the inner preform 14 and falls off. While tightly fitting the outer preform 13 and the inner preform 14 together at the mouth 15a can prevent the outer preform 13 from falling off, this creates a new problem in that the inner bag 4 is difficult to detach from the outer shell 3 in the container body 2 obtained by molding.

[0046] Therefore, in this embodiment, in order to make it possible to easily pull out the inner bag 4 from the outer shell 3 after use while preventing the outer preform 13 from falling off, the inner preform 14 and the outer preform 13 are engaged with each other via a concave-convex structure at the mouth portion 15a.

[0047] 9, in this embodiment, the concave-convex engagement is an engagement between an engaging protrusion 14h provided on the outer peripheral surface of the mouth portion 14a of the inner preform 14 and an engaging recess 13m provided on the inner surface of the mouth portion 13a of the outer preform 13. The engaging protrusion 14h and the engaging recess 13m become the engaging protrusion 4h and the engaging recess 3m, respectively.

[0048] <Materials and manufacturing method of the inner preform 14 and the outer preform 13> The inner preform 14 and the outer preform 13 can be formed by direct blow molding, injection molding, or the like using thermoplastic resin such as polyester (e.g., PET) or polyolefin (e.g., polypropylene, polyethylene). In one example, the inner preform 14 is made of polyolefin (e.g., polypropylene), and the outer preform 13 is made of PET.

[0049] The inner preform 14 is preferably formed by direct blow molding. Direct blow molding (blow molding using a molten cylindrical parison) makes it easy to form the inner preform 14 with a laminated structure. The outer preform 13 is preferably formed by injection molding.

[0050] 2. Other embodiments It is not essential that the mouth-attached member 8 be engaged with the inner bag 4, and the inner bag 4 may be directly gripped to rotate or pull out the inner bag 4. The cam mechanism 31 may be any mechanism that can change the relative rotation between the inner bag 4 and the outer shell 3 into axial movement of the inner bag 4 .

[0051] 3. Notes The original claims of the original application are attached. [1] A double container comprising a container body having an inner bag and an outer shell, wherein the double container is configured such that the inner bag moves in a direction away from the outer shell by rotating the inner bag relative to the outer shell. [2] The double container according to [1], wherein the inner bag is movable by a cam mechanism. [3] A double container according to [2], wherein the cam mechanism is provided on the outer peripheral surface of the inner bag and the inner peripheral surface of the outer shell. [4] The double container according to any one of [1] to [3], further comprising a mouth attachment member, the mouth attachment member comprising a main body and a band, the main body and the band being connected to each other via an easily tearable connecting part, the band engaging with the mouth of the outer shell in the circumferential and axial directions, the main body engaging with the mouth of the inner bag in the circumferential and axial directions, and the band being configured to be separable from the main body by tearing the connecting part. According to the present invention, the following inventions are provided. [Explanation of symbols]

[0052] 1:Double container 2: Container body 3: Outer shell 3a: Open end 3f: Recess 3k: Engagement convex part 3l: Cam rail 3l1: Convex part 3m: Engagement recess 4: Inner bag 4c:Protrusion 4c1:Protruding tube 4c2: Engagement convex part 4c3: Tapered surface 4c4: Abutting flange 4g: Cam protrusion 4h: Engagement protrusion 5: Mouth 5a: Engagement part 5a2: Annular convex part 5b: Flange 5c: Open end 5c1: Opening surface 6: Body 6b:Shoulder 6c: Body 7: Bottom 8: Mouth attachment member 13: Outer preform 13a: Mouth 13b: Torso 13c: Bottom 13d: Annular convex part 13l: Cam rail 13m: Engagement recess 14: Inner preform 14a: Mouth 14b: Torso 14c: Bottom 14c1: Locating pin 14d:Protrusion 14g: Cam protrusion 14h: Engagement protrusion 15: Preform 15a: Mouth 15b: Body 15c: bottom 18: Mouth attachment member 28: Main body 28a: Outer cylinder 28b: Inner cylinder 28c: Annular convex part 28d: Engagement convex part 28e: Top plate 28f:Discharge port 29: Band Club 29a: Engagement protrusion 29a1: Tapered surface 29b: Engagement recess 29c: Notch 30:Connection part 31: Cam mechanism

Claims

1. A double container comprising a container body having an inner bag and an outer shell, the container body is a biaxially stretched blow molded article, A double container, wherein the inner bag and the outer shell are engaged with each other in an axial direction at the mouth of the container body.

2. The double container according to claim 1, The double container is configured so that the engagement between the inner bag and the outer shell can be released by relative rotation of the inner bag and the outer shell.

3. The double container according to claim 1 or claim 2, The concave-convex engagement is constituted by a convex portion provided on the outer peripheral surface of the inner bag and a concave portion provided on the inner peripheral surface of the outer shell.

4. The double container according to claim 1 or claim 2, The container body has a mouth and a shoulder, The shoulder portion is a portion whose outer diameter increases with increasing distance from the mouth portion, The inner bag and the outer shell abut at the shoulder portion.

5. The double container according to claim 4, A double container, wherein the outer surface of the inner bag and the inner surface of the outer shell have the same inclination angle at the shoulder portion.

6. The double container according to claim 1 or claim 2, A double container comprising a stopper-type mouth attachment member attached to the mouth of the container body.

7. The double container according to claim 1 or claim 2, the inner bag and the mouth attachment member each include a plurality of engaging protrusions spaced apart in the circumferential direction, The double container has an engaging protrusion on the inner bag and an engaging protrusion on the spout attachment member, which engage with each other in the circumferential direction of the inner bag and the spout attachment member.

8. The double container according to claim 1 or claim 2, a mouth attachment member that is attached to the mouth of the container body, The inner bag is configured to rotate in accordance with the rotation of the mouth attachment member.

9. The double container according to claim 1 or claim 2, The inner bag has a cylindrical shape at the entire portion facing the mouth of the outer shell.

10. The double container according to claim 1 or claim 2, A double container configured so that the inner bag does not shrink when the contents of the inner bag are discharged.

11. A method for removing an inner bag from a double container according to claim 1 or 2, comprising: The method comprises the step of directly grasping the inner bag and rotating the inner bag.

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