Double container

Abstract

To provide a double container excellent in recyclability.SOLUTION: According to the present invention, there is provided a double container comprising a container body and a mouth attachment member. The container body comprises an inner bag and an outer shell arranged to cover the inner bag. The inner bag has a projection part protruding from an opening end of the outer shell. The container body is configured such that, when viewed from above the double container, when the inner bag is rotated in one direction relative to the outer shell, the inner bag is displaced in a direction in which it comes out of the container body, and the mouth attachment member and the projection part are screwed together such that the relative rotation of the mouth attachment member in the one direction relative to the projection part is the tightening direction of the screwing.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, a double container having a container body having an outer shell and an inner bag is known. For example, Patent Document 1 discloses a double container formed by performing biaxial stretch blow molding on an outer shell preform and an inner bag preform in a stacked state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-10741 A 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 molded 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] It is also conceivable that the outer shell and the inner bag will be separated with the cap attached to the inner bag, and if the cap and the inner bag are formed from different materials, it is desirable for the cap and the inner bag to also be separated.

[0006] The present invention has been made in view of the above circumstances, and aims to provide a double-layered container with excellent recyclability. [Means for solving the problem]

[0007] According to the present invention, the following inventions are provided. [1] A double container comprising a container body 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 having a protrusion protruding from the open end of the outer shell, the container body being configured such that, when viewed from above the double container, the inner bag is displaced in a direction such that it comes out of the container body when the inner bag is rotated in one direction relative to the outer shell, and the mouth attachment member and the protrusion are screwed together such that the relative rotation of the mouth attachment member in one direction relative to the protrusion is the tightening direction of the screwing. [2] The double container according to [1], wherein the one direction is a counterclockwise direction when viewed from above the double container. [3] A double container as described in [1] or [2], wherein the mouth attachment member is attached to the protrusion with a tightening torque less than a threshold torque required to rotate the inner bag relative to the outer shell. [4] A double container as described in [1] or [2], wherein the protrusion has a male threaded portion, the mouth attachment member has a female threaded portion that can be screwed into the male threaded portion, and at least one of the male threaded portion and the female threaded portion is an intermittent threaded portion formed intermittently in the circumferential direction. Effect of the Invention

[0008] The double container of the present invention is configured to make it easier to pull out the inner bag from the container body by rotating the inner bag in one direction relative to the outer shell, and is configured so that when the mouth attachment member is rotated in the one direction relative to the protruding portion of the inner bag, the mouth attachment member is screwed onto the protruding portion. With this configuration, when the mouth attachment member is gripped and rotated in one direction, the inner bag also rotates in the same direction and is displaced in a direction that allows it to come out of the container body, making it easier to pull out the inner bag from the container body. After the inner bag is pulled out from the container body, when the mouth attachment member is rotated in the other direction relative to the protruding portion, the screw engagement between the mouth attachment member and the protruding portion is released, and the mouth attachment member and the inner bag can be separated, making it possible to recycle the mouth attachment member and the inner bag separately. Therefore, according to the present invention, a double container with excellent recyclability is obtained. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view of a double container 1 according to a first embodiment of the present invention. The dashed and dotted lines in the figure indicate the boundary line where the curvature of the faces constituting the surface shape changes. The same is true for the other figures. [Diagram 2] FIG. 2 is an exploded perspective view of the double container 1 of FIG. [Diagram 3] 2 is a longitudinal cross-sectional view of the double container 1 of FIG. 1 with the overcap 42 closed. [Figure 4] FIG. 4 is an exploded view of FIG. 3 with the overcap 42 slightly open. [Diagram 5] FIG. 3 is an exploded perspective view of the vicinity of the mouth portion 5 in FIG. 2. [Figure 6] Fig. 6A is a perspective view of the cap body 41 of the mouth-mounted member 8 in Fig. 2, seen from a different angle. Fig. 6B is a cross-sectional perspective view of the cap body 41 in Fig. 6A cut in half. [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] 1 is a perspective view of a preform 15 formed by covering an inner preform 14 with an outer preform 13. FIG. [Figure 9] 5, in which a concave-convex engagement structure made up of protrusions 4g1 and 3m1 is provided as a rotation restricting structure for restricting rotation of inner bag 4 relative to outer shell 3. FIG. [Figure 10] 13 is a cross-sectional view showing a state in which an intermittent thread portion 4m2 is provided on an inner bag 4, and an intermittent thread portion 8b2 is provided on a cap body 41. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present invention will be described. The various features shown in the following embodiments can be combined with each other. Each feature can be an independent invention. In the following embodiments, elements that are not specified in the claims are optional elements and can be omitted.

[0011] 1. First embodiment The double container according to the first embodiment of the present invention will be described with reference to Figs. 1 to 8. In the following description, terms related 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 Fig. 2) of the mouth 5 extends, 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, in other words, the direction in which the inner bag 4 is rotated at the mouth 5 relative to the outer shell 3.

[0012] 1-1. Structure of double container 1 <Overall composition> As shown in FIG. 1, the double container 1 of the first embodiment of the present invention includes a container body 2 and a mouth attachment member 8. As shown in FIGS. 3 and 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 includes a protruding portion 4c protruding from an open end 3a of the outer shell 3. The container body 2 is configured such that when the inner bag 4 is rotated in one direction relative to the outer shell 3 as viewed from above the double container 1, the inner bag 4 is displaced in a direction to come out of the container body 2. The mouth attachment member 8 and the protruding portion 4c are configured to be screwable together such that the relative rotation of the mouth attachment member 8 in the one direction relative to the protruding portion 4c is the tightening direction of the screwing. In this embodiment, the one direction is a counterclockwise direction as viewed from above the double container 1. Hereinafter, "clockwise" and "counterclockwise" refer to the directions as viewed from above the double container 1 unless otherwise specified. Each configuration will be described in detail below.

[0013] <Basic configuration of container body 2> As shown in Figs. 2 and 3, the container body 2 comprises a mouth 5, a trunk 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. The mouth 5 comprises an engagement portion 4m to which a mouth attachment member 8 can be attached. 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.

[0014] 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 a 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.

[0015] 3 to 5, 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 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.

[0016] <Detailed structure of outer shell 3 and inner bag 4> 2 to 5, the inner bag 4 has a protruding portion 4c protruding from the open end 3a of the outer shell 3. The protruding portion 4c has a protruding tube 4c1, an engaging portion 4m, and a contacting protrusion 4v.

[0017] In this embodiment, the engagement portion 4m is a reverse-threaded male screw portion 4m1. The engagement portion 4m is disposed at a position closer to the open end 5c of the inner bag 4 than the contact protrusion 4v. As shown in Fig. 4, a recess 4c13 is provided on the inner peripheral surface of the engagement portion 4m.

[0018] The contact protrusion 4v is disposed at a position where it contacts the open end 3a and is a portion that protrudes radially outward from the protruding tube 4c1. The contact protrusion 4v contacts the open end 3a, thereby preventing the inner bag 4 from falling off into the outer shell 3. The contact protrusion 4v is composed of one or more protrusions.

[0019] 5, a ridge 4g is provided on the outer circumferential 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.

[0020] As shown in Fig. 5, the inner peripheral surface of the outer shell 3 is provided with a cam rail 3l and a groove 3m. The groove 3m is provided so that the lower surface of the groove 3m is continuous with the upper surface of the cam rail 3l. The upper surface of the cam rail 3l is inclined so as to approach the opening end 3a as it progresses in the counterclockwise direction. The protrusion 4g and the groove 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 with each other by rotating the inner bag 4 counterclockwise relative to the outer shell 3.

[0021] The container body 2 is preferably provided with a rotation restriction structure that restricts the relative rotation between the inner bag 4 and the outer shell 3. Examples of the 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. In this embodiment, it is preferable to adopt a structure in which the width of the convex strip 4g is slightly larger than the width of the concave strip 3m to cause strong interference. As shown in FIG. 9, an example of a structure that engages the inner bag 4 and the outer shell 3 in a concave-convex manner is a structure in which a protrusion 4g1 provided on the convex strip 4g and a protrusion 3m1 provided at a position adjacent to the concave strip 3m are engaged in a concave-convex manner. The protrusion 4g1 and the protrusion 3m1 are arranged at positions where the protrusion 4g engages with the concave strip 3m. When the inner bag 4 is rotated counterclockwise relative to the outer shell 3 in a state in which the protrusion 4g1 and the protrusion 3m1 are engaged, the protrusion 4g1 and the protrusion 3m1 come into contact with each other, and the rotation of the inner bag 4 relative to the outer shell 3 is restricted. When the torque applied to the inner bag 4 is increased, the projections 4g1 and 3m1 are deformed, so that the projections 4g1 overcome the projections 3m1 and the restriction on rotation is released.

[0022] 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. 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 causes it to come out of the container body 2. At this time, the inner bag 4 is twisted and reduced in diameter. The cam mechanism 31 has an inclined structure in the same direction as a positive screw.

[0023] <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 may be another member such as a pump. As shown in FIG. 4, the mouth attachment member 8 has an engagement portion 8b that can be engaged with the engagement portion 4m. The engagement portion 8b is preferably a reverse-threaded female screw portion 8b1 that can be screwed with a reverse-threaded male screw portion 4m1. 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 has a nozzle 8c.

[0024] 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 protruding portion 4c, and includes an outlet 8d. The overcap 42 is configured to be able to open and close the outlet 8d. FIG. 3 shows a closed state in which the outlet 8d is closed, and FIG. 4 shows an open state in which the outlet 8d is open. In this embodiment, the cap body 41 and the overcap 42 are connected by a hinge 43, but they do not have to be connected. The overcap 42 is preferably able to engage with the cap body 41 by a screw or a snap fit.

[0025] The cap body 41 includes an outer tube 41a, an inner tube 41b, a nozzle 8c, an upper wall 41d, and an upper engagement portion 41e. 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 becomes the discharge port 8d. The upper engagement portion 41e is disposed above the upper wall 41d. The upper engagement portion 41e is configured to be able to engage with the overcap 42.

[0026] The inner cylinder 41b is inserted into the protruding portion 4c and is in close contact with the inner surface of the protruding portion 4c. The outer cylinder 41a has an inner peripheral surface provided with an engagement portion 8b that engages with the engagement portion 4m of the protruding portion 4c.

[0027] The overcap 42 includes an outer tube 42a, an inner tube 42b, an upper wall 42d, and an engagement portion 42e. 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 is not provided with a discharge port for discharging the contents in the inner bag 4. The engagement portion 42e is provided on the inner peripheral surface of the outer tube 42a. The overcap 42 is attached to the cap body 41 by the engagement portion 42e engaging with the upper engagement portion 41e.

[0028] With the discharge port 8d closed by the overcap 42, the inner tube 42b is inserted into the nozzle 8c of the cap body 41 and is in close contact with the inner surface of the nozzle 8c. In addition, the bottom surface of the outer tube 42a abuts against the upper wall 41d of the cap body 41. From this state, by gripping the outer tube 42a and applying an upward force to the overcap 42, the overcap 42 can be separated from the cap body 41 to open the discharge port 8d.

[0029] <Attachment of mouth attachment member 8> The mouth attachment member 8 can be attached to the mouth 5 by placing the mouth attachment member 8 on the mouth 5, rotating it counterclockwise, and screwing the male screw portion 4m1 and the female screw portion 8b1 together. At this time, if the mouth attachment member 8 is tightened too much, there is a risk that the inner bag 4 will rotate counterclockwise relative to the outer shell 3 and be displaced so as to slip out of the container body 2. In order to suppress the rotation of the inner bag 4 relative to the outer shell 3, it is preferable that the mouth attachment member 8 is attached to the protruding portion 4c with a tightening torque less than the threshold torque required to rotate the inner bag 4 relative to the outer shell 3. In order to increase the threshold torque, it is preferable that the container body 2 is provided with a rotation restriction structure that restricts the relative rotation of the inner bag 4 and the outer shell 3 in the direction in which the inner bag 4 slips out of the container body 2, as described above.

[0030] The mouth mounting member 8 may be attached to the protruding portion 4c by a plugging method. In this case, when a downward force is applied to the mouth mounting member 8 with the mouth mounting member 8 placed over the protruding portion 4c, the helical protrusion constituting the female screw portion 8b1 can ride over the helical protrusion constituting the male screw portion 4m1 to engage the female screw portion 8b1 with the male screw portion 4m1. In this case, as shown in FIG. 10, it is preferable that at least one of the female screw portion 8b1 and the male screw portion 4m1 is an intermittent screw portion 8b2, 4m2 formed intermittently in the circumferential direction. According to this configuration, in addition to reducing the force required to engage the female screw portion 8b1 with the male screw portion 4m1, when the female screw portion 8b1 rides over the male screw portion 4m1, it is easy to make the female screw portion 8b1 and the male screw portion 4m1 engaged by rotating the mouth mounting member 8 relative to the protruding portion 4c. When the mouth attachment member 8 is attached to the protruding portion 4c by a plugging method, no force is applied to the inner bag 4 in the circumferential direction, and therefore the above-mentioned rotation restriction structure is not essential.

[0031] <Removing inner bag 4> When the mouth attachment member 8 is gripped and rotated counterclockwise relative to the container body 2, the rotational force is transmitted to the protruding portion 4c of the inner bag 4 via the reverse-threaded engagement formed by the male screw portion 4m1 and the female screw portion 8b1, and the mouth portion 5 of the inner bag 4 rotates. When the mouth portion 5 of the inner bag 4 rotates, the inner bag 4 moves in a direction to come out of the container body 2 due to the action of the cam mechanism 31 provided between the inner bag 4 and the outer shell 3. At this time, the inner bag 4 is twisted and reduced in diameter. The mouth attachment member 8 is engaged with the inner bag 4 in the axial direction by the engagement of the male screw portion 4m1 and the female screw portion 8b1. Therefore, the inner bag 4 can be pulled out of the container body 2 by gripping and pulling the mouth attachment member 8.

[0032] Since counterclockwise is the tightening direction of the reverse thread, when the mouth attachment member 8 is rotated, the reverse thread engagement between the male thread portion 4m1 and the female thread portion 8b1 does not loosen, and the rotational force applied to the mouth attachment member 8 is reliably transmitted to the mouth 5 of the inner bag 4.

[0033] After the inner bag 4 has been pulled out, the mouth attachment member 8 is rotated clockwise relative to the inner bag 4 to release the screw engagement between the mouth attachment member 8 and the inner bag 4, allowing the mouth attachment member 8 and the inner bag 4 to be separated, making it possible to recycle the mouth attachment member 8 and the inner bag 4 separately. Thus, according to the present invention, a double container 1 with excellent recyclability is obtained.

[0034] 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 the mouth attachment member 8 to the container body 2.

[0035] <Configuration of inner preform 14, outer preform 13, and preform 15> As shown in FIG. 7, the preform 15 includes an inner preform 14 which becomes the inner bag 4 and an outer preform 13 which becomes the outer shell 3 .

[0036] As shown in Fig. 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 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.

[0037] 8, the 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.

[0038] 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. The mouth portion 15a is hardly deformed during molding and becomes the mouth portion 5 of the container body 2. The above-mentioned 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 is not contrary to the spirit thereof.

[0039] <Materials and manufacturing methods of inner preform 14, outer preform 13, and preform 15> The inner preform 14 and the outer preform 13 can be formed by direct blow molding or injection molding using a thermoplastic resin such as polyester (eg, PET) or polyolefin (eg, polypropylene, polyethylene).

[0040] 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 engagement portion 4m can be obtained. The inner preform 14 is preferably of a multi-layer structure.

[0041] 2. Other embodiments The direction in which each member is rotated relative to the above embodiment may be reversed. In the above embodiment, the inner bag 4 is displaced in a direction coming out of the container body 2 by rotating the positive screw in the loosening direction, and the mouth attachment member 8 is screwed into the protruding portion 4c by rotating the negative screw in the tightening direction, but the inner bag 4 may be displaced in a direction coming out of the container body 2 by rotating the positive screw in the loosening direction, and the mouth attachment member 8 may be screwed into the protruding portion 4c by rotating the positive screw in the tightening direction. In this case, the "one direction" referred to in the first embodiment is the clockwise direction. [Explanation of symbols]

[0042] 1:Double container 2: Container body 3: Outer shell 3a: Open end 3l: Cam rail 3m: Concave 3m1 :Protrusion 4: Inner bag 4c:Protrusion 4c1:Protruding tube 4c13: Recess 4d: Inner bag body 4g: Convex stripe 4g1 :Protrusion 4m: Engagement part 4m1: Male thread 4m2: Intermittent thread section 4v: Contact convex part 5: Mouth 5b: Flange 5c: Open end 6: Torso 6b:Shoulder 6c: Main body 7: Bottom 8: Mouth attachment member 8a: Cap 8b: Engagement part 8b1: Female thread 8b2: Intermittent thread section 8c: Nozzle 8d:Discharge port 13: Outer preform 13a: Mouth 13b: Torso 13c: Bottom 14: Inner preform 14a: Mouth 14b: Torso 14c: Bottom 15: Preform 15a: Mouth 15b: Torso 15c: bottom 31: Cam mechanism 41: Cap body 41a: Outer cylinder 41b: Inner cylinder 41d: Upper wall 41e: Upper engagement part 41i :Flow hole 42: Overcap 42a: Outer cylinder 42b: Inner cylinder 42d: Upper wall 42e: Engagement part 43: Hinge C: Central axis

Claims

1. A double container comprising a container body and a mouth attachment member, The container body includes an inner bag and an outer shell arranged to cover the inner bag. The inner bag has a protrusion protruding from an open end of the outer shell, The container body is configured such that, when viewed from above the double container, the inner bag is displaced in a direction to come out of the container body when the inner bag is rotated in one direction relative to the outer shell, The mouth attachment member and the protrusion are screwed together such that the relative rotation of the mouth attachment member with respect to the protrusion in the one direction corresponds to a tightening direction of the screwing.

2. The double container according to claim 1, The double container, wherein the one direction is a counterclockwise direction when viewed from above the double container.

3. The double container according to claim 1 or 2, The mouth attachment member is attached to the protrusion with a tightening torque less than a threshold torque required to rotate the inner bag relative to the outer shell.

4. The double container according to claim 1 or 2, The protruding portion is provided with a male thread portion, The mouth attachment member is provided with a female screw portion that can be screwed into the male screw portion, At least one of the male thread portion and the female thread portion is an intermittent thread portion formed intermittently in the circumferential direction.

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