Double container and method for manufacturing the same

Abstract

To provide a double container in which outside air is easily introduced into an intermediate space between an outer shell and an inner bag in a barrel part of a container body.SOLUTION: According to the present invention, there is provided a double container including a container body, wherein the container body includes an inner bag and an outer shell disposed so as to cover the inner bag, the container body is provided with a cam mechanism and a rotation restricting mechanism, and the cam mechanism is configured to displace the inner bag in a direction in which the inner bag comes out of the container body by rotation of the inner bag with respect to the outer shell, the rotation restricting mechanism is configured to restrict rotation of the inner bag with respect to the outer shell in a state where a gap is formed between the outer shell and the inner bag at a mouth portion of the container main body by rotating the inner bag with respect to the outer shell. Since the double-walled container of the present invention is excellent in recyclability, it can be suitably used for producing a recycled material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Patent document 1 discloses a double container that is configured so that the inner bag can be rotated relative to the outer shell by rotating a mouth attachment member that is circumferentially engaged with the inner bag relative to the outer shell, thereby twisting the inner bag to reduce its diameter, and then the mouth attachment member can be pulled to pull the inner bag out of the container body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2024-018821 Summary of the Invention [Problem to be solved by the invention]

[0004] The double-layered container disclosed in Patent Document 1 can be used as a peelable container in which the inner bag separates from the outer shell and shrinks as the contents inside the inner bag are dispensed. When used for such purposes, it is necessary to introduce outside air into the intermediate space between the outer shell and the inner bag at the body of the container body. Outside air can be introduced from the interface between the outer shell and the inner bag at the mouth of the container body, but if the outer shell and the inner bag are in close contact at the mouth of the container body, it may be difficult for outside air to reach the body.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a double container that makes it easy to introduce outside air into the intermediate space between the outer shell and the inner bag at the barrel of the container body. [Means for solving the problem]

[0006] According to the present invention, the following inventions are provided: [1] A double-layered container comprising a container body, the container body comprising an inner bag and an outer shell arranged to cover the inner bag, the container body being provided with a cam mechanism and a rotation-restricting mechanism, the cam mechanism being configured to displace the inner bag in a direction to come out of the container body by rotation of the inner bag relative to the outer shell, and the rotation-restricting mechanism being configured to restrict rotation of the inner bag relative to the outer shell in a state in which a gap is formed between the outer shell and the inner bag at the opening of the container body by rotating the inner bag relative to the outer shell. [2] 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 container body being provided with a cam mechanism, the cam mechanism being configured to displace the inner bag in a direction of coming out of the container body by rotation of the inner bag relative to the outer shell, and a gap being formed between the outer shell and the inner bag at the mouth of the container body due to the rotation of the inner bag relative to the outer shell. [3] A double container according to [1] or [2], wherein the cam mechanism comprises a cam rail and a cam protrusion, the cam rail being composed of an inclined surface provided on the inner surface of the outer shell, and the cam protrusion being provided on the outer surface of the inner bag, and wherein the double container is configured such that the cam protrusion moves along the cam rail as the inner bag rotates relative to the outer shell, thereby displacing the inner bag. [4] [3] A double container as described above, wherein a recess capable of accommodating the cam protrusion is provided in a portion of the cam rail, and when the cam protrusion is accommodated in the recess, the outer shell and the inner bag are in abutment with each other at their abutment surfaces, and when the inner bag is rotated relative to the outer shell from this abutment state, the abutment between the outer shell and the inner bag at the abutment surfaces is released. [5] A double container according to [3] or [4] citing [1], wherein the rotation restriction mechanism includes at least one engagement protrusion provided along the cam rail. [6] A double container according to any one of [1] to [5], wherein the outer shell has a flange portion, the container body has the mouth portion, a body portion, and a bottom portion, the mouth portion has an upper mouth portion and a lower mouth portion, the upper mouth portion is the portion between the open end of the container body and the underside of the flange portion, the lower mouth portion is the portion between the upper mouth portion and the body portion, the portion below the underside of the flange portion where the outer diameter of the container body begins to expand is the base of the lower mouth portion, the bottom portion is the portion that closes the lower end of the body portion, and the outer shell has an inner tapered portion in at least a part of the lower mouth portion that is configured so that the inner diameter of the outer shell narrows toward the base. [7] A double container according to any one of [1] to [6], comprising a mouth attachment member that is attached to the mouth of the container body, the mouth attachment member having an outside air introduction hole that communicates with the intermediate space between the outer shell and the inner bag. [8] A double container according to [7], wherein the mouth attachment member is provided with an air flow restriction member that restricts the flow of air through the outside air introduction hole. [9] A double container according to [7] or [8], wherein the mouth attachment member is in close contact with both the inner bag and the outer shell.

[10] A method for producing a double-layered container according to any one of [1] to [9], wherein the container body is formed by biaxially stretched blow molding. [Effects of the Invention]

[0007] The double container of the present invention is configured to restrict the rotation of the inner bag relative to the outer shell while forming a gap between the outer shell and the inner bag at the mouth of the container body by rotating the inner bag relative to the outer shell, thereby making it easy to introduce outside air into the intermediate space between the outer shell and the inner bag at the body of the container body. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view of a double container 1 according to a first embodiment of the present invention. 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 exploded perspective view of the double container 1 of FIG. [Figure 3] Fig. 3A is a longitudinal cross-sectional view of the double container 1 of Fig. 1. Fig. 3B is an enlarged view of region B in Fig. 3A. [Figure 4] FIG. 4 is an exploded view of FIG. 3. [Figure 5] FIG. 2 is an exploded perspective view of the vicinity of the mouth 5 of the container body 2. [Figure 6] Fig. 6A is a cross-sectional view corresponding to Fig. 3A, showing a state after gap 2c has been formed between outer shell 3 and inner bag 4. Fig. 6B is an enlarged view of region B in Fig. 6A. [Figure 7] FIG. 2 is a perspective view showing a state in which the inner preform 14 and the outer preform 13 are separated. [Figure 8] FIG. 2 is a perspective view of a preform 15. DETAILED DESCRIPTION OF THE INVENTION

[0009] The following describes embodiments of the present invention. The 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 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."

[0010] The embodiments shown below include at least the inventions of the following aspects.

[0011] The invention of the first aspect is as follows: A double container comprising a container body, The container body includes an inner bag and an outer shell disposed to cover the inner bag, The container body is provided with a cam mechanism and a rotation restriction mechanism, the cam mechanism is configured to displace the inner bag in a direction to be removed from the container body by rotation of the inner bag relative to the outer shell, The rotation restriction mechanism is a double container that is configured to restrict the rotation of the inner bag relative to the outer shell by rotating the inner bag relative to the outer shell, thereby forming a gap between the outer shell and the inner bag at the mouth of the container body.

[0012] The invention of the second aspect is as follows: A double container comprising a container body, The container body includes an inner bag and an outer shell disposed to cover the inner bag, The container body is provided with a cam mechanism, the cam mechanism is configured to displace the inner bag in a direction to be removed from the container body by rotation of the inner bag relative to the outer shell, This is a double container, in which a gap is formed between the outer shell and the inner bag at the mouth of the container body as the inner bag rotates relative to the outer shell.

[0013] 1. First embodiment The double-sided container according to the first embodiment of the present invention will be described with reference to Figures 1 to 8. 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. In addition, 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, or in other words, 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, or in other words, the direction in which the inner bag 4 is rotated at the mouth 5 relative to the outer shell 3. Unless otherwise specified, "clockwise" and "counterclockwise" refer to directions as viewed from the top of the double-sided container 1.

[0014] 1-1. Structure of double container 1 1 and 3, the double container 1 of the first embodiment of the present invention comprises a container body 2, a spout mounting member 8, and an air flow restricting member 53. Each component will be described in detail below.

[0015] <Configuration of container body 2> 2 and 3, 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.

[0016] 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 equivalent circular 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.

[0017] As shown in Fig. 4, the mouth 5 has an upper mouth 5a and a lower mouth 5b. The upper mouth 5a is the region between the open end 5c of the container body 2 and the lower surface 5d1 of the flange 5d. The lower mouth 5b is the region between the upper mouth 5a and the body 6. The base 5b1 of the lower mouth 5b is the region below the lower surface 5d1 of the flange 5d where the outer diameter of the container body 2 begins to expand.

[0018] As shown in Fig. 4, 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 has an inner bag body 4d other than a 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.

[0019] <Configuration of the mouth portion 5 of the 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. 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.

[0020] A lower surface 4b4 of the second tube 4b abuts against the outer shell 3. The lower surface 4b4 abuts against an inner bag support surface 3a3 provided on the outer shell 3. Support of the lower surface 4b4 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 opening end 3a, or may be provided at a higher or lower position than the opening end 3a. In this embodiment, the inner bag support surface 3a3 is provided at a lower position than the opening end 3a. Therefore, a portion of the second tube 4b is disposed inside the outer shell 3, and the remainder is disposed outside the outer shell 3.

[0021] <Configuration of mouth portion 5 of outer shell 3> As shown in Figure 4, the outer peripheral surface of the outer shell 3 is provided with an expanded diameter portion 3o and a flange portion 5d in this order from the opening end 3a of the outer shell 3. The expanded diameter portion 3o is formed by expanding the diameter of the opening end 3a. A recess is preferably provided on the inner peripheral surface of the expanded diameter portion 3o. The lower surface of this recess serves as the inner bag support surface 3a3.

[0022] At least a part of lower opening 5b of outer shell 3 has inner tapered portion 3p configured so that the inner diameter of outer shell 3 narrows toward base 5b1 of lower opening 5b. In this case, the force required to pull out inner bag 4 is reduced, and gap 2c is more likely to be formed.

[0023] The outer shell 3 preferably has an outer tapered portion 3q in at least a part of the lower opening 5b so that the outer diameter of the outer shell 3 decreases toward the base 5b1. In this case, the inner tapered portion 3p is more likely to be formed.

[0024] If the lengths of the lower opening 5b, the inner tapered portion 3p, and the outer tapered portion 3q in the axial direction of the mouth 5 of the container body 2 are L, Li, and Lo, respectively, then Li / L and Lo / L are each preferably 0.50 to 1.00 (in this embodiment, both are 1.00). In this case, the force required to pull out the inner bag 4 is more effectively reduced. Li / L and Lo / L are each preferably 0.75 to 1.00, and specific examples of these values ​​are 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, and 1.00, and may be within a range between any two of the values ​​exemplified here.

[0025] <Configuration of cam mechanism 31> As shown in FIG. 5, the container body 2 is provided with a cam mechanism 31. The cam mechanism 31 is configured to displace the inner bag 4 in a direction away from the container body 2 by rotation of the inner bag 4 relative to the outer shell 3. In this embodiment, the cam mechanism 31 includes a cam rail 3l and a cam protrusion 4n. The cam rail 3l is configured with an inclined surface provided on the inner peripheral surface of the outer shell 3. The cam rail 3l is inclined so as to approach the open end 3a as it moves counterclockwise or clockwise (counterclockwise in this embodiment). With this configuration, as the inner bag 4 rotates relative to the outer shell 3, the cam protrusion 4n moves along the cam rail 3l, displacing the inner bag 4 in a direction away from the container body 2. As shown in FIG. 6, a gap 2c is formed between the outer shell 3 and the inner bag 4 (more specifically, between the inner bag support surface 3a3 of the outer shell 3 and the underside 4b4 of the inner bag 4). In this embodiment, since the outer shell 3 is provided with the inner tapered portion 3p, a gap 2c is likely to be formed at the lower opening 5b as the inner bag 4 is displaced.

[0026] A recess 3r capable of accommodating the cam protrusion 4n is provided in a portion of the cam rail 3l. Preferably, when the cam protrusion 4n is accommodated in the recess 3r, the outer shell 3 and the inner bag 4 are in contact with each other at a contact surface 55, as shown in Fig. 3B. In this embodiment, the contact surface 55 is the surface where the inner bag support surface 3a3 of the outer shell 3 and the lower surface 4b4 of the inner bag 4 come into contact. When the inner bag 4 is rotated relative to the outer shell 3 from this contact state, the contact between the outer shell 3 and the inner bag 4 at the contact surface 55 is released.

[0027] <Configuration of rotation restriction mechanism 54> As shown in Fig. 5, the container body 2 is provided with a rotation restriction mechanism 54. The rotation restriction mechanism 54 is configured to restrict rotation of the inner bag 4 relative to the outer shell 3 in a state in which a gap 2c is formed between the outer shell 3 and the inner bag 4 at the opening 5 of the container body 2 by rotating the inner bag 4 relative to the outer shell 3. The rotation restriction mechanism 54 restricts rotation of the inner bag 4 in both directions relative to the outer shell 3. This prevents the inner bag 4 from accidentally rotating in a direction away from the container body 2, causing the inner bag 4 to slip out of the container body 2, or prevents the inner bag 4 from accidentally rotating in a direction toward the inside of the container body 2, narrowing the gap 2c between the outer shell 3 and the inner bag 4.

[0028] The rotation restriction mechanism 54 preferably includes at least one engagement protrusion 3s provided along the cam rail 3l. The engagement protrusion 3s interferes with the cam protrusion 4n, restricting the movement of the cam protrusion 4n, thereby restricting the rotation of the inner bag 4. In this embodiment, the engagement protrusion 3s is provided so as to protrude from the upper surface of the cam rail 3l, but it may also be provided so as to protrude from the inner peripheral surface of the outer shell 3, for example. In this embodiment, the rotation restriction mechanism 54 is provided so as to protrude from the upper surface of the cam rail 3l along the cam rail 3l. The cam protrusion 4n has a pair of engagement protrusions 3s spaced apart from each other. When the cam protrusion 4n is positioned between the pair of engagement protrusions 3s, the movement of the cam protrusion 4n in one direction and the other direction is restricted by the engagement protrusions 3s, thereby restricting the rotation of the inner bag 4 in both directions. Alternatively, for example, a recess may be formed in the cam protrusion 4n, and this recess may be engaged with the engagement protrusion 3s. In this case, the movement of the cam protrusion 4n in one direction and the other direction can be restricted by one engagement protrusion 3s.

[0029] In addition, in the invention in which the gap 2c is formed between the outer shell 3 and the inner bag 4 at the mouth 5 of the container body 2 by rotating the inner bag 4 relative to the outer shell 3, the rotation restricting mechanism 54 can be omitted.

[0030] <Configuration of mouth-mounted member 8> The mouth attachment member 8 is a member that is 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. As shown in FIG. 4, the mouth attachment member 8 has an engaging portion 8b that can engage with an engaging portion 4m provided on the mouth 5 of the inner bag 4. When the engaging portion 8b engages with the engaging portion 4m, the mouth attachment member 8 engages with the mouth 5 (preferably the protruding portion 4c) of the inner bag 4 in the axial direction.

[0031] The spout-attaching member 8 preferably also circumferentially engages with the spout 5 (preferably the protruding portion 4c) of the inner bag 4. In this embodiment, as shown in Fig. 2, the engaging portion 4m is provided with a plurality of engaging protrusions 4c2 spaced apart along the circumferential direction, and the engaging protrusions 4c2 engage with the spout-attaching member 8 in the circumferential direction.

[0032] The mouth-mounted member 8 preferably has a discharge port 8d for discharging the contents in the inner bag 4. The mouth-mounted member 8 also preferably includes a nozzle 8c.

[0033] The cap 8a preferably includes a cap body 41 and an overcap 42. The cap body 41 is configured to be able to engage with the protrusion 4c and includes a discharge port 8d. The overcap 42 is configured to be able to open and close the discharge port 8d.

[0034] The cap body 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 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 closely contacts the inner surface 4f1 of the cylindrical seal portion 4f. An engagement portion 8b is provided on the inner peripheral surface of the outer tube 41a. The outer tube 41a closely contacts the outer shell 3. More specifically, the inner peripheral surface of the outer tube 41a closely contacts the outer peripheral surface of the outer shell 3 (more specifically, the outer peripheral surface of the expanded diameter portion 3o). In this way, the mouth attachment member 8 is in close contact with both the outer shell 3 and the inner bag 4, and therefore the intermediate space between the outer shell 3 and the inner bag 4 becomes a sealed space.

[0035] The cap body 41 is provided with a discharge valve 44. The discharge valve 44 is configured to allow the content to be discharged and to prevent outside air from entering the inner bag 4. In this embodiment, the discharge valve 44 is provided in the nozzle 8c, but it may also be provided in, for example, the upper wall 41d.

[0036] The spout-mounted member 8 has an outside air introduction hole 8h that communicates with the intermediate space between the outer shell 3 and the inner bag 4. More specifically, the outside air introduction hole 8h is provided in the cap body 41 (more specifically, the outer tube 41a). Outside air can be introduced into the intermediate space between the outer shell 3 and the inner bag 4 through the outside air introduction hole 8h. As shown in FIG. 3 , the outside air introduction hole 8h is located at a position farther from the open end 41a1 of the outer tube 41a than the contact surface 56 between the outer tube 41a and the outer shell 3.

[0037] <Configuration of Air Flow Restriction Member 53> The mouth-mounted member 8 is preferably provided with an air flow restriction member 53 that restricts the flow of air through the outside air introduction hole 8h. When the outer shell 3 is pressed from the outside of the container body 2 to expel the contents of the inner bag 4, the air flow restriction member 53 is configured to either allow air to flow out of the intermediate space between the outer shell 3 and the inner bag 4 to an extent that the pressure in the intermediate space increases to facilitate the expulsion of the contents, or to prevent air from flowing out. When pressure is stopped, the air flow restriction member 53 is configured to allow air to flow into the intermediate space from outside the container body 2 so that the shape of the outer shell 3 is restored.

[0038] Examples of the air flow restriction member 53 include a check valve that restricts the flow of air as the mobile object moves, and a breathable membrane that allows a small amount of air to flow. The breathable membrane may be, for example, a microporous membrane made primarily of polytetrafluoroethylene (PTFE), and the microporous membrane may be a composite of nonwoven fabric and polyethylene terephthalate (PET) mesh. The means for attaching the air flow restriction member 53 to the mouth-attached member 8 is not limited, and may be any of engagement, press-fitting, welding, adhesion, etc. The air flow restriction member 53 is preferably placed inside the outside air introduction hole 8h.

[0039] <Attachment of mouth attachment member 8> As shown in Fig. 4, the mouth attachment member 8 can be attached to the mouth 5 with the enlarged diameter portion 3o or the flange portion 5d supported. The mouth attachment member 8 is preferably of a plugging type, and when the mouth attachment member 8 is placed over the protruding portion 4c with the enlarged diameter portion 3o or the flange portion 5d supported and a downward force is applied to the mouth attachment member 8 in this state, the engaging portion 8b climbs over the engaging portion 4m, and the engaging portion 8b and the engaging portion 4m engage in the axial direction, allowing the mouth attachment member 8 to be attached to the mouth 5 (preferably the protruding portion 4c).

[0040] <Use of double container 1> In this embodiment, the nozzle-mounted member 8 is provided with a discharge valve 44, which allows the inner bag 4 to contract as the contents of the inner bag 4 are discharged. Furthermore, an outside air inlet hole 8h is provided through the outer shell 3, allowing the inner bag 4 to separate from the outer shell 3 and contract as the contents are discharged. A gap 2c is formed between the outer shell 3 and the inner bag 4 as the inner bag 4 rotates relative to the outer shell 3, allowing outside air to smoothly enter the intermediate space in the barrel 6 of the container body 2. Furthermore, an air flow restriction member 53 is provided to restrict the flow of air through the outside air inlet hole 8h. Compressing the outer shell 3 increases the pressure in the intermediate space, allowing the contents to be discharged from the inner bag 4. When the compressive force on the outer shell 3 is removed and the outer shell 3 returns to its original shape, outside air is introduced into the intermediate space, allowing the outer shell 3 to quickly return to its original shape. Therefore, this embodiment allows for a squeeze-type peelable container to be realized.

[0041] <Pull out inner bag 4> The mouth attachment member 8 is axially engaged with the mouth 5 of the inner bag 4, so by pulling the mouth attachment member 8, the inner bag 4 can be pulled out of the container body 2. Furthermore, if the mouth attachment member 8 is also circumferentially engaged with the mouth 5 of the inner bag 4, the inner bag 4 can be twisted and reduced in diameter by rotating the mouth attachment member 8. This reduces the force required to pull out the inner bag 4.

[0042] Furthermore, since the container body 2 is provided with a cam mechanism 31, as the inner bag 4 rotates, the inner bag 4 moves in the direction of coming out of the container body 2. Therefore, by rotating the spout attachment member 8, the inner bag 4 can be moved in the direction of coming out of the container body 2 while twisting, and thereafter, by pulling the spout attachment member 8, the inner bag 4 can be pulled out of the container body 2.

[0043] 1-2. Manufacturing method of double container 1 The container body 2 can be manufactured by biaxially stretching and blow molding a preform 15 shown in Fig. 8. In addition, the double container 1 can be manufactured by attaching a mouth attachment member 8 to the container body 2.

[0044] <Configuration of inner preform 14, outer preform 13, and preform 15> As shown in FIG. 7, the preform 15 includes an inner preform 14 that will become the inner bag 4 and an outer preform 13 that will become the outer shell 3.

[0045] 7, the inner preform 14 is cylindrical with a bottom and includes a mouth portion 14a, a body portion 14b, and a bottom portion 14c. The bottom portion 14c is provided so as to close the lower end of the body portion 14b. The inner preform 14 is provided with a cam protrusion 14n that becomes the cam protrusion 4n.

[0046] 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. The outer preform 13 is provided with a recess 13r that will become the recess 3r.

[0047] 8, the preform 15 can be formed by covering the inner preform 14 with the outer preform 13. At this time, it is preferable to prevent the inner preform 14 from coming off the outer preform 13 by engaging the cam protrusions 14n with the recesses 13r.

[0048] 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 biaxial 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 configuration included in the mouth portion 5 can also be applied to the configuration included in the mouth portion 15a, as long as it is not contrary to the intent thereof.

[0049] <Materials and manufacturing methods for inner preform 14, outer preform 13, and preform 15> The inner preform 14 and the outer preform 13 can be formed from a thermoplastic resin such as polyester (e.g., PET) or polyolefin (e.g., polypropylene, polyethylene). The inner preform 14 and the outer preform 13 can be formed by direct blow molding or injection molding. The inner preform 14 is preferably formed by direct blow molding using a tubular parison in a molten state. Direct blow molding has the advantage that it is easier to make thinner and multi-layered parts than injection molding.

[0050] <Formation of gap 2c> The gap 2c between the outer shell 3 and the inner bag 4 can be formed at any timing. The gap 2c may be formed before or after biaxial stretch blow molding. However, from the viewpoint of preventing the inner preform 14 from coming off the outer preform 13, it is preferable to engage the cam protrusion 14n provided on the inner preform 14 with the recess 13r provided on the outer preform 13 before biaxial stretch blow molding. Furthermore, from the viewpoint of the stability of biaxial stretch blow molding, it is preferable that the inner preform 14 is pressed axially against the outer preform 13 during biaxial stretch blow molding. For this reason, it is preferable to form the gap 2c after biaxial stretch blow molding. In other words, it is preferable to form the container body 2 by performing biaxial stretch blow molding while the inner preform 14 and the outer preform 13 are abutting at a position corresponding to the gap 2c, and then rotate the inner bag 4 relative to the outer shell 3 to form the gap 2c.

[0051] 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 the direction of coming out of the container body 2 by rotating the clockwise screw in the loosening direction, but the inner bag 4 may be displaced in the direction of coming out of the container body 2 by rotating the counterclockwise screw in the loosening direction. [Explanation of symbols]

[0052] 1:Double container 2: Container body 2c: Gap 3: Outer shell 3a: Open end 3a3: inner bag support surface 3l: Cam rail 3o: Expanded diameter part 3p: Inner tapered section 3q: Outer tapered section 3r: Recess 3s: Engagement protrusion 4: Inner bag 4a: 1st tube 4b: 2nd tube 4b4:Bottom surface 4c:Protrusion 4c2: Engagement convex part 4d: Inner bag body 4f: Seal cylinder 4f1: Inner surface 4m: Engagement part 4n: Cam protrusion 5: Mouth 5a: Upper mouth part 5b: Lower mouth part 5b1 : Root 5c: Open end 5d: Flange part 5d1: Bottom surface 6: Body 6b:Shoulder 6c: Body 7: Bottom 8: Mouth attachment member 8a: Cap 8b: Engagement part 8c: Nozzle 8d:Discharge port 8h: Outside air intake 13: Outer preform 13a: Mouth 13b: Torso 13c: Bottom 13r: Recess 14: Inner preform 14a: Mouth 14b: Torso 14c: Bottom 14n: Cam protrusion 15: Preform 15a: Mouth 15b: Body 15c: bottom 31: Cam mechanism 41: Cap body 41a: Outer cylinder 41a1: Open end 41b: Inner cylinder 41d: Upper wall 41i :Flow hole 42: Overcap 44: Discharge valve 53: Air flow control member 54: Rotation restriction mechanism 55: Contact surface 56: Contact surface C: Central axis

Claims

1. A double container comprising a container body, The container body includes an inner bag and an outer shell disposed to cover the inner bag, The container body is provided with a cam mechanism and a rotation restriction mechanism, the cam mechanism is configured to displace the inner bag in a direction to be removed from the container body by rotation of the inner bag relative to the outer shell, The rotation restriction mechanism is configured to restrict the rotation of the inner bag relative to the outer shell by rotating the inner bag relative to the outer shell, thereby forming a gap between the outer shell and the inner bag at the mouth of the container body.

2. A double container comprising a container body, The container body includes an inner bag and an outer shell disposed to cover the inner bag, The container body is provided with a cam mechanism, the cam mechanism is configured to displace the inner bag in a direction to be removed from the container body by rotation of the inner bag relative to the outer shell, A double container, wherein a gap is provided between the outer shell and the inner bag at the mouth of the container body, the gap being formed as the inner bag rotates relative to the outer shell.

3. The double container according to claim 1 or claim 2, The cam mechanism includes a cam rail and a cam protrusion. the cam rail is formed by an inclined surface provided on the inner circumferential surface of the outer shell, The cam protrusion is provided on the outer peripheral surface of the inner bag, The double container is configured such that the cam protrusion moves along the cam rail as the inner bag rotates relative to the outer shell, thereby displacing the inner bag.

4. The double container according to claim 3, A recess capable of accommodating the cam protrusion is provided in a portion of the cam rail, When the cam protrusion is housed in the recess, the outer shell and the inner bag are in contact with each other at their contact surfaces, When the inner bag is rotated relative to the outer shell from the abutting state, the abutment between the outer shell and the inner bag at the abutment surface is released.

5. A double container according to claim 3 which relies on claim 1, The rotation restriction mechanism includes at least one engagement protrusion provided along the cam rail.

6. The double container according to claim 1, The outer shell includes a flange portion, The container body includes the mouth, a body, and a bottom, The mouth portion includes an upper mouth portion and a lower mouth portion, the upper opening portion is a portion between the open end of the container body and the lower surface of the flange portion, the lower opening is a portion between the upper opening and the body, a portion where the outer diameter of the container body begins to increase below the lower surface of the flange portion is the base of the lower opening portion; the bottom portion is a portion that closes the lower end of the body portion, The outer shell has an inner tapered portion configured such that the inner diameter of the outer shell narrows toward the base at at least a portion of the lower opening.

7. The double container according to claim 1, a mouth attachment member that is attached to the mouth of the container body, The double container, wherein the mouth attachment member has an outside air introduction hole communicating with an intermediate space between the outer shell and the inner bag.

8. The double container according to claim 7, The double container is provided with an air flow restriction member on the mouth attachment member that restricts the flow of air through the outside air introduction hole.

9. The double container according to claim 7, The mouth attachment member is in close contact with both the inner bag and the outer shell, forming a double container.

10. A method for manufacturing a double container according to claim 1, The method wherein the container body is formed by biaxially stretch blow molding.

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