Double-walled container and method for manufacturing the same

Abstract

This invention provides a double-walled container that can regulate the airflow between the intermediate space and the external space without forming an external air intake hole in the container body. [Solution] According to the present invention, a double-walled container is provided, comprising a container body and a mouth attachment member, wherein the container body comprises an inner bag and an outer shell disposed to cover the inner bag, the mouth attachment member is attached to the mouth of the container body, the mouth attachment member comprises a main body member attached to the container body and an airflow restricting member, the main body member comprises an outer cylinder disposed on the outside of the mouth, the outer cylinder has through holes on its circumferential surface, the airflow restricting member is attached to the main body member so as to restrict the flow of air through the through holes, and the airflow restricting member restricts the airflow between the intermediate space between the outer shell and the inner bag and the external space of the double-walled container. Furthermore, the double-walled container of the present invention has excellent recyclability and is therefore suitable for use in the manufacture of recycled materials.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a method for manufacturing a double container by biaxial stretch blow molding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the double container of Patent Document 1, an outside air introduction hole is provided in the container body, and a check valve is engaged and attached to this outside air introduction hole, so that when the outer shell is compressed, air leakage from the intermediate space between the outer shell and the inner bag is suppressed, and when the compression of the outer shell is released, the air flow is regulated so that air can flow from the external space of the container into the intermediate space.

[0005] In the configuration of Patent Document 1, it is essential to accurately form an outside air introduction hole in the container body, but it is not easy to accurately form an outside air introduction hole in the container body, and it is desired to regulate the air flow between the intermediate space and the external space without forming an outside air introduction hole in the container body.

[0006] The present invention has been made in view of such circumstances, and provides a double container capable of regulating the air flow between the intermediate space and the external space without forming an outside air introduction hole in the container body.

Means for Solving the Problems

[0007] According to the present invention, the following inventions are provided. [1] A double-walled container comprising a container body and a mouth attachment member, wherein the container body comprises an inner bag and an outer shell disposed to cover the inner bag, the mouth attachment member is attached to the mouth of the container body, the mouth attachment member comprises a main body member attached to the container body and an airflow restricting member, the main body member comprises an outer cylinder disposed on the outside of the mouth, the outer cylinder has through holes on its circumferential surface, the airflow restricting member is attached to the main body member so as to restrict the flow of air through the through holes, and the airflow restricting member restricts the airflow between the intermediate space between the outer shell and the inner bag and the external space of the double-walled container. A double-walled container as described in [2][1], wherein the airflow restricting member is located on the inner surface side of the outer cylinder. A double-walled container according to [3] [1] or [2], wherein the airflow restricting member is a valve body that changes the opening of the through-hole by deformation or displacement. A double container as described in [4][3], wherein the valve body is an annular valve, and the annular valve is arranged so that its outer surface and the inner surface of the outer cylinder face each other. A double-walled container as described in any one of [5][1] to [4], wherein the outer cylinder is in close contact with the outer shell at the outer shell contact portion, the inner bag has a protruding portion that protrudes from the outer shell, the outer cylinder has an engaging portion that engages with an axial engaging portion provided on the protruding portion, and the through hole is located between the engaging portion and the outer shell contact portion. A method for manufacturing a double-walled container according to any one of [6][1] to [5], wherein the container body is formed by biaxial stretch blow molding of a preform. [Effects of the Invention]

[0008] In the double-walled container of the present invention, the airflow restricting member is configured to restrict the airflow through through-holes provided on the circumferential surface of the outer cylinder. With this configuration, the airflow between the intermediate space and the external space can be restricted without forming an outside air intake hole in the container body. Furthermore, since the through-holes are provided on the circumferential surface of the outer cylinder, communication between the through-holes and the intermediate space is easier compared to, for example, the case where the through-holes are provided on the upper wall of the main body member. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a double-walled container 1 according to the first embodiment of the present invention. The dashed lines in the figure represent boundary lines where the curvature of the surfaces constituting the surface shape changes. The same applies to the other figures. [Figure 2] Figure 1 is an exploded view of the double-walled container 1. [Figure 3] Figure 2 is an exploded view of the vicinity of the mouth 5 of the container body 2. [Figure 4] Figure 1 is a longitudinal cross-sectional view of the double-walled container 1. [Figure 5] Figure 4 is an exploded view. [Figure 6] Figure 6A is an end view of line AA in Figure 4. Figure 6B is a cross-sectional view corresponding to Figure 6A, showing the state in which the annular valve 53a is bent and a gap is formed between the annular valve 53a and the outer cylinder 41a. [Figure 7] Figure 7A is a perspective view of the mouth attachment member 8 from Figure 2, viewed from a different direction. Figure 7B is an exploded view of Figure 7A. [Figure 8] This is a perspective view showing the inner preform 14 and outer preform 13 separated. [Figure 9] This is a perspective view of a preform 15 constructed by covering an inner preform 14 with an outer preform 13. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Various features shown in the embodiments described below can be combined with each other. Also, an invention can be made independently for each feature. Furthermore, among the following embodiments, elements not defined in the claims are arbitrary elements and can be omitted. At the end of the numerical values disclosed in the following description, any number (for example, one or two) of "0"s may be added. For example, one or two "0"s may be added after "1.4" to be "1.40" or "1.400".

[0011] 1. First Embodiment The double container 1 of the first embodiment of the present invention will be described with reference to FIGS. 1 to 9. Terms related to directions such as "up" and "down" in the following description mean the directions in the state where the bottom 7 is grounded. Also, the "axial direction" in the following description is the direction in which the central axis C (shown in FIG. 2) of the mouth portion 5 extends, for example, the direction in which the inner bag 4 is pulled out from the container body 2. The "circumferential direction" is the rotational direction around the central axis C of the mouth portion 5, for example, the direction in which the inner bag 4 is rotated with respect to the outer shell 3 at the mouth portion 5. "Clockwise" and "counterclockwise" are the directions as viewed from the upper side of the double container 1 unless otherwise specified.

[0012] 1-1. Configuration of the double container 1 <Basic configuration> As shown in FIGS. 1 to 2, the double container 1 of the first embodiment of the present invention includes a container body 2 and a mouth attachment member 8. The double container 1 is a bottle-shaped container capable of storing beverages, seasonings, etc. The double container 1 is, for example, a squeeze-type container configured to be able to discharge the contents inside the container body 2 by compressing the body portion 6 of the container body 2. Hereinafter, each configuration will be described in detail.

[0013] The container body 2 includes a mouth portion 5, a body portion 6, and a bottom portion 7. The mouth portion 5 is a cylindrical (preferably circular cylindrical) portion having an open end 5c. The open end 5c is the open end of the container body 2 and also the open end of the inner bag 4.

[0014] The body portion 6 is disposed adjacent to the mouth portion 5 on the side away from the opening end 5c of the mouth portion 5. The body portion 6 has a larger outer diameter than the mouth portion 5 (in this specification, the "outer diameter" means the equivalent diameter of a circle when the cross-section is not circular). The body portion 6 is cylindrical, and the bottom portion 7 is provided at the lower end of the body portion 6 and closes the lower end of the body portion 6. The body portion 6 includes a shoulder portion 6b whose outer diameter increases as it moves away from the mouth portion 5. Further, the body portion 6 includes a body portion main body 6c on the side of the bottom portion 7 rather than the shoulder portion 6b. The body portion main body 6c has a shape including, for example, a portion where the outer diameter is substantially constant toward the bottom portion 7 or a portion where the diameter decreases toward the bottom portion 7.

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

[0016] <The outer shell 3 and the inner bag 4> As shown in FIGS. 3 and 5, an engaging portion 4m to which the mouth attachment member 8 can be attached is provided on the protruding portion 4c of the inner bag 4. The engaging portion 4m includes an axial engaging portion 4ma that axially engages with the mouth attachment member 8 and a circumferential engaging portion 4mb that circumferentially engages with the mouth attachment member 8. The circumferential engaging portion 4mb can be omitted if unnecessary. The outer shell 3 is provided with first and second flange portions 3f1 and 3f2 in order from the opening end 3a side.

[0017] The inner bag 4 includes a first cylinder 4a and a second cylinder 4b. The first cylinder 4a is disposed in the outer shell 3. The second cylinder 4b has a larger outer diameter than the first cylinder 4a and is disposed at a position closer to the opening end 5c of the inner bag 4 than the first cylinder 4a. The second cylinder 4b may be entirely disposed outside the outer shell 3, or a part or all of the second cylinder 4b may be disposed in the outer shell 3 and the remainder may be disposed outside the outer shell 3.

[0018] The second cylinder 4b comprises a circumferential wall 4b1 and a lower wall 4b2 provided below the circumferential wall 4b1 and configured to reduce the diameter of the circumferential wall 4b1 toward the first cylinder 4a. The circumferential wall 4b1 preferably has a portion that extends parallel to the axial direction. The lower wall 4b2 preferably is located inside the outer shell 3.

[0019] As shown in Figure 3, the inner bag 4 has a recess 4h in the portion facing the outer shell 3. The recess 4h is formed by recessing the inner bag 4 inward. The inner bag 4 has a recess 4h in the portion facing the outer shell 3, and air can be introduced through the recess 4h into the intermediate space SP1 (shown in Figure 4) between the inner bag 4 and the outer shell 3. As shown in Figure 2, it is preferable that the recess 4h is provided so as to extend to a position higher than the open end 3a of the outer shell 3. In this case, the airflow through the recess 4h becomes even smoother.

[0020] As shown in Figure 3, the recess 4h is provided at the corner 4b3 between the lower wall 4b2 and the peripheral wall 4b1. In this case, the recess 4h functions as a reinforcing rib, increasing the rigidity of the second cylinder 4b, making it easier to rotate the inner bag 4 relative to the outer shell 3 when pulling out the inner bag 4. Furthermore, the corner 4b3 is located inside the outer shell 3. In this case, a gap is less likely to form between the inner bag 4 and the outer shell 3, highlighting the significant technical importance of providing the recess 4h to facilitate the introduction of air into the intermediate space SP1 between the inner bag 4 and the outer shell 3.

[0021] As shown in Figure 5, it is preferable that the lower surface 4b4 of the second cylinder 4b is supported by contact with the inner bag support surface 3a3. By supporting the lower surface 4b4 with the inner bag support surface 3a3, the inner bag 4 is prevented from falling into the outer shell 3. The inner bag support surface 3a3 may be flush with the opening end 3a, or it may be located at a lower position than the opening end 3a. In this embodiment, the inner bag support surface 3a3 is located at a lower position than the opening end 3a. Therefore, a part of the second cylinder 4b is located inside the outer shell 3, and the rest is located outside the outer shell 3.

[0022] Preferably, a cam mechanism 31 is provided between the inner bag 4 and the outer shell 3, which functions to displace the inner bag 4 in a direction that allows it to detach from the container body 2 by rotating the inner bag 4 clockwise or counterclockwise (hereinafter referred to as the "loosening direction") relative to the outer shell 3. The cam mechanism 31 can be composed of, for example, a protrusion 4g provided on the outer circumferential surface of the inner bag 4 and a cam rail 3l provided on the inner circumferential surface of the outer shell 3. When the inner bag 4 is rotated relative to the outer shell 3 at the opening 5, the inner bag 4 is twisted and its diameter is reduced, making it easier to pull out the inner bag 4.

[0023] Furthermore, before the inner bag 4 is pulled out of the container body 2, it is preferable that the protrusion 4g is positioned within the recess 3m provided on the outer shell 3. The outer shell 3 is provided with an engaging projection 3j at a position that contacts the protrusion 4g when the protrusion 4g attempts to displace in the loosening direction. By the protrusion 4g contacting the engaging projection 3j, the displacement of the protrusion 4g is suppressed, thereby preventing the inner bag 4 from unexpectedly coming out. A projection 4k is provided on the downstream side of the protrusion 4g in the loosening direction. The lower surfaces of the protrusion 4g and the projection 4k are similarly inclined. By providing the projection 4k, even if the protrusion 4g falls off the cam rail 3l when it overcomes the engaging projection 3j, the projection 3k moves along the cam rail 3l, allowing the cam mechanism 31 to function. In addition, the inner bag 4 is provided with a movement-restricting part 4p. The movement-restricting part 4p contacts the contact surface 3s of the outer shell 3 when attempting to rotate the inner bag 4 in the opposite direction to the loosening direction. This prevents the inner bag 4 from being accidentally rotated in the wrong direction. The movement-restricting part 4p is provided on the projection 4k.

[0024] <Mouth attachment member 8> As shown in Figures 1 and 2, the mouth attachment member 8 is attached to the mouth 5 of the container body 2, and preferably to the protruding portion 4c of the inner bag 4. In this embodiment, the mouth attachment member 8 is a cap 8a.

[0025] As shown in Figures 4 and 5, the mouth attachment member 8 preferably comprises a main body member 41, an opening / closing member 42, and an airflow restricting member 53. The main body member 41 is a member attached to the container body 2. The main body member 41 is attached to the inner bag 4 (more specifically, the protruding portion 4c). The main body member 41 has a discharge port 8d for discharging the contents of the inner bag 4. The opening / closing member 42 is configured to open and close the discharge port 8d. The opening / closing member 42 preferably can be engaged with the main body member 41 by a screw or snap fit. The opening / closing member 42 can be omitted if it is not needed.

[0026] The main body member 41 comprises an outer cylinder 41a, an inner cylinder 41b, an upper wall 41d, a discharge valve 44, and a nozzle member 46. The outer cylinder 41a is positioned outside the mouth portion 5. Through holes 41k are provided on the circumferential surface of the outer cylinder 41a. In this embodiment, there are two through holes 41k, but there may be one or three or more. Since the through holes 41k are provided on the circumferential surface of the outer cylinder 41a, communication between the through holes 41k and the intermediate space SP1 is easier compared to the case where the through holes 41k are provided on the upper wall 41d. Furthermore, if the through holes 41k are provided on the upper wall 41d, there is a risk that the through holes 41k may be blocked by the opening / closing member 42, but in this embodiment, since the through holes 41k are provided on the outer cylinder 41a, the above problem does not occur.

[0027] The airflow restricting member 53 is attached to the main body member 41 to restrict the airflow through the through hole 41k. The airflow restricting member 53 restricts the airflow between the external space SP2 and the intermediate space SP1. Examples of the airflow restricting member 53 include a ventilation membrane that allows a small amount of airflow, and a valve body that restricts the airflow by changing the opening of the through hole 41k through deformation or displacement.

[0028] It is preferable that the airflow restricting member 53 is attached to the outer cylinder 41a. It is preferable that the airflow restricting member 53 is positioned on the inner surface side of the outer cylinder 41a. It is preferable that the airflow restricting member 53 does not protrude outwards from the outer surface side of the outer cylinder 41a. In this case, the airflow restricting member 53 is difficult to see from the outside and has a superior aesthetic appearance. It is preferable that the airflow restricting member 53 is not inserted into the through hole 41k. It is preferable that the airflow restricting member 53 is a separate member independent of the main body member 41. In this case, after preparing the main body member 41 and the airflow restricting member 53 separately, the airflow restricting member 53 can be attached to the main body member 41 by joining means such as engagement or adhesive. It is preferable that the airflow restricting member 53 can be attached to and detached from the main body member 41 even after being attached to the main body member 41. It is preferable that the airflow restricting member 53 is composed of a single member. In this case, it is easier to reduce the cost of materials compared to a valve composed of multiple members, such as a ball valve in which a ball moves inside the cylinder.

[0029] The airflow restricting member 53 is preferably an annular valve 53a. The angle at which the annular valve 53a extends circumferentially in a cross section perpendicular to the central axis C and passing through the through hole 41k (more specifically, the center of the through hole 41k) (i.e., the cross section in Figure 6A) is, for example, 90 to 360 degrees (360 degrees in this embodiment), preferably 180 to 360 degrees, and more preferably 270 to 360 degrees. In other words, the annular valve 53a may be a complete annular shape (i.e., the above angle is 360 degrees), or it may have a shape in which a part of the ring is missing (i.e., the above angle is less than 360 degrees). These angles are specifically, for example, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, and 360 degrees, and may also be within a range between any two of the values ​​exemplified here.

[0030] The annular valve 53a has advantages such as a simple structure and a low space occupancy rate within the outer cylinder 41a. Preferably, the annular valve 53a is a complete or partially missing cylindrical shape. Preferably, the annular valve 53a is positioned concentrically with the outer cylinder 41a. The outer circumferential surface of the annular valve 53a faces the inner circumferential surface of the outer cylinder 41a. Preferably, the outer circumferential surface of the annular valve 53a is similar in shape to the inner circumferential surface of the outer cylinder 41a. When no compressive force is applied to the body 6 of the double container 1, the outer circumferential surface of the annular valve 53a may or may not be in contact with the inner circumferential surface of the outer cylinder 41a.

[0031] An annular housing portion 41m is provided on the inner circumferential surface of the outer cylinder 41a in a region including the through hole 41k. The annular housing portion 41m is configured to accommodate the annular valve 53a. By placing the annular valve 53a within the annular housing portion 41m, the annular valve 53a can be positioned appropriately without providing any other joining means. The annular housing portion 41m is provided between the annular projection 41p and the engaging portion 8b.

[0032] Preferably, the annular valve 53a has the flexibility to deform in response to pressure changes in the intermediate space SP1 when the double container 1 is in use, thereby opening and closing the through hole 41k.

[0033] The thickness of the annular valve 53a is not particularly limited, and is, for example, 0.1 to 1.0 mm (0.3 mm in this embodiment), preferably 0.1 to 0.7 mm, and more preferably 0.2 to 0.4 mm. Specifically, this thickness may be, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 mm, and may be in the range between any two of the values ​​exemplified here.

[0034] The width (i.e., axial length) of the annular valve 53a is, for example, 2 to 10 mm (4.8 mm in this embodiment), and preferably 3 to 7 mm. Specifically, this width may be, for example, 2, 3, 4, 5, 6, 7, 8, 9, or 10 mm, and may be in the range between any two of the values ​​exemplified here.

[0035] Examples of materials for the annular valve 53a include soft resins such as low-density polyethylene and elastomers, and silicone rubber.

[0036] An engaging portion 8b is provided on the inner circumferential surface of the outer cylinder 41a. The engaging portion 8b is composed of an annular projection that protrudes radially inward from the outer cylinder 41a. Between the engaging portion 8b and the upper wall 41d, a plurality of engaging protrusions 41j are provided, which protrude radially inward from the outer cylinder 41a. The plurality of engaging protrusions 41j are spaced apart in the circumferential direction. The main body member 41 engages axially with the projection 4c when the engaging portion 8b engages axially with the axial engaging portion 4ma. The main body member 41 engages circumferentially with the projection 4c when the engaging protrusions 41j engage circumferentially with the circumferential engaging portion 4mb.

[0037] The inner cylinder 41b is positioned inside the outer cylinder 41a. The outer cylinder 41a and the inner cylinder 41b are connected via the upper wall 41d. The discharge valve 44 is configured to allow the discharge of the contents inside the inner bag 4 and to prevent outside air from entering the inner bag 4. The nozzle member 46 is a member having a nozzle 8c and is mounted on the upper wall 41d. The tip of the nozzle 8c becomes the discharge port 8d. In this embodiment, the discharge valve 44 is positioned inside the inner cylinder 41b, but it may be positioned in another location, such as inside the nozzle 8c.

[0038] The opening / closing member 42 comprises an outer cylinder 42a, an inner cylinder 42b, and an upper wall 42d. The inner cylinder 42b is positioned inside the outer cylinder 42a. The outer cylinder 42a and the inner cylinder 42b are connected via the upper wall 42d. The upper wall 42d does not have an outlet for discharging the contents of the inner bag 4.

[0039] When the discharge port 8d is closed by the opening / closing member 42, the inner cylinder 42b is inserted into the nozzle 8c of the main body member 41 and is in close contact with the inner surface of the nozzle 8c. Also, the bottom surface of the outer cylinder 42a abuts against the upper wall 41d of the main body member 41. From this state, by gripping the outer cylinder 42a and applying an upward force to the opening / closing member 42, the opening / closing member 42 can be separated from the main body member 41 and the discharge port 8d can be opened.

[0040] As shown in Figure 4, the main body member 41 includes an inner bag contact portion 41n in which the main body member 41 is in close contact with the inner bag 4, and an outer shell contact portion 41l in which the main body member 41 is in close contact with the outer shell 3. A sealed space SP3 composed of the main body member 41 and the container body 2 is formed between the inner bag contact portion 41n and the outer shell contact portion 41l. In this embodiment, the inner bag contact portion 41n is formed when 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 (more specifically, the inner surface 4f1 of the seal cylinder portion 4f). In this embodiment, the outer shell contact portion 41l is formed when the inner circumferential surface of the outer cylinder 41a (more specifically, the tip portion 41a1 of the outer cylinder 41a) is in close contact with the outer circumferential surface of the outer shell 3 (more specifically, the first flange portion 3f1).

[0041] The through-hole 41k is positioned to communicate with the sealed space SP3 provided between the main body member 41 and the container body 2. Furthermore, the recess 4h of the inner bag 4 is also positioned to communicate with the sealed space SP3. With this configuration, air from the external space SP2 of the double container 1 is easily introduced into the intermediate space SP1 through the through-hole 41k, the sealed space SP3, and the recess 4h. Preferably, the through-hole 41k is positioned between the engaging portion 8b and the outer shell contact portion 41l. With this configuration, air from the external space SP2 is easily introduced into the intermediate space SP1 through the through-hole 41k. In this embodiment, the sealed space SP3 communicates with the intermediate space SP1 through the gap between the open end 3a of the outer shell 3 and the protruding portion 4c of the inner bag 4. Therefore, it is not necessary to provide an opening in the outer shell 3 for air circulation.

[0042] <Attachment of mouth attachment member 8> As shown in Figure 5, the mouth mounting member 8 can be attached to the mouth 5 while supporting the first flange portion 3f1 or the second flange portion 3f2. The mouth mounting member 8 is preferably of the plug type, and while supporting the first flange portion 3f1 or the second flange portion 3f2, the mouth mounting member 8 is placed over the protrusion portion 4c, and when a downward force is applied to the mouth mounting member 8 in this state, the engaging portion 8b overcomes the axial engaging portion 4ma, and the engaging portion 8b engages with the axial engaging portion 4ma, thereby attaching the mouth mounting member 8 to the mouth 5. At this time, the engaging projection 41j engages with the circumferential engaging portion 4mb, causing the main body member 41 to engage with the protrusion portion 4c in the circumferential direction.

[0043] <Operation of Double Container 1> When the user presses the body 6 of the container body 2 to dispense the contents from the double-walled container 1, the outer shell 3 is compressed. The air flow restricting member 53 suppresses air leakage from the intermediate space SP1 when the outer shell 3 is compressed, so the pressure in the intermediate space SP1 increases with the compression of the outer shell 3, making it easier for the compressive force applied to the outer shell 3 to be transmitted to the inner bag 4. As a result, the inner bag 4 is compressed along with the compression of the outer shell 3, and the contents inside the inner bag 4 are dispensed through the discharge valve 44. The inner bag 4 is contracted by the discharge of the contents. The discharge valve 44 is configured to prevent outside air from entering the inner bag 4, so no outside air enters the inner bag 4, and the inner bag 4 remains contracted.

[0044] When the compression of the outer shell 3 is released, the outer shell 3 attempts to return to its original shape due to its own restoring force. At this time, the pressure in the intermediate space SP1 decreases. The air flow restricting member 53 is configured to allow air to flow from the external space SP2 to the intermediate space SP1 when the compression of the outer shell 3 is released. As a result of the decrease in pressure in the intermediate space SP1, outside air is quickly introduced into the intermediate space SP1, and the outer shell 3 is quickly restored to its original shape.

[0045] When the airflow restricting member 53 is an annular valve 53a, as shown in Figure 6A, when the outer shell 3 is compressed, the annular valve 53a is pressed against the inner surface of the outer cylinder 41a, thereby closing the through hole 41k and suppressing air leakage from the intermediate space SP1. When the outer shell 3 is released from compression, as shown in Figure 6B, the annular valve 53a deflects as the pressure in the intermediate space SP1 decreases, creating a gap between the annular valve 53a and the outer cylinder 41a, allowing air to flow in through the through hole 41k.

[0046] <Pulling out inner bag 4> The mouth attachment member 8 is engaged with the protrusion 4c of the inner bag 4 in the circumferential and axial directions, and is configured to rotate relative to the outer shell 3 so that the inner bag 4 twists as the mouth attachment member 8 rotates. Furthermore, due to the action of a cam mechanism 31 provided between the inner bag 4 and the outer shell 3, the inner bag 4 moves in a direction that allows it to detach from the container body 2 as it rotates. In addition, at the body 6 and bottom 7, the inner bag 4 is less likely to rotate relative to the outer shell 3 compared to the mouth 5, so when the inner bag 4 is rotated relative to the outer shell 3 at the mouth 5, the inner bag 4 is twisted.

[0047] With this configuration, by rotating the mouth attachment member 8, the inner bag 4 can be twisted and moved in a direction that allows it to come out of the container body 2. After that, by pulling the mouth attachment member 8, the inner bag 4 can be pulled out of the container body 2.

[0048] 1-2. Manufacturing method of double-walled container 1 The container body 2 can be manufactured by biaxial stretch blow molding the preform 15 shown in Figure 9. Furthermore, the double-walled container 1 can be manufactured by attaching the mouth attachment member 8 to the container body 2.

[0049] <Composition: Inner preform 14, outer preform 13, and preform 15> The preform 15 comprises an inner preform 14 which becomes the inner bag 4 and an outer preform 13 which becomes the outer shell 3.

[0050] As shown in Figure 8, the inner preform 14 is a bottomed cylindrical shape and comprises a mouth 14a, a body 14b, and a bottom 14c. The bottom 14c is provided to close the lower end of the body 14b. The outer preform 13 is a bottomed cylindrical shape and comprises a mouth 13a, a body 13b, and a bottom 13c. The bottom 13c is provided to close the lower end of the body 13b.

[0051] As shown in Figure 9, the preform 15 can be formed by placing the outer preform 13 over the inner preform 14.

[0052] 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 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 description of the components included in the mouth portion 5 is also applicable to the components included in the mouth portion 15a, insofar as it does not contradict the purpose of the description.

[0053] <Materials and manufacturing methods for inner preform 14, outer preform 13, and preform 15> The inner preform 14 and outer preform 13 can be formed from thermoplastic resins such as polyester (e.g., PET) or polyolefins (e.g., polypropylene, polyethylene). 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 molten cylindrical parison. Direct blow molding has the advantage of making it easier to thin the wall and create multiple layers compared to injection molding.

[0054] 2. Other Embodiments In the above embodiment, the mouth attachment member 8 is attached to the inner bag 4 by engaging the mouth attachment member 8 with the inner bag 4 in the axial direction. However, the mouth attachment member 8 may also be attached to the outer shell 3 by engaging the mouth attachment member 8 with the outer shell 3 in the axial direction. In the above embodiment, the mouth attachment member 8 is attached to the container body 2 by a stopper, but it may also be attached to the container body 2 by a screw. [Explanation of symbols]

[0055] 1:Double container 2: Container body 3: Outer shell 3a: Open end 3a3: Inner bag support surface 3f1: First flange section 3f2: Second flange section 3j: Engagement protrusion 3k:Protrusion 3L: Cam Rail 3m: Concave 3s: Contact surface 4: Inner bag 4a: 1st tube 4b: 2nd cylinder 4b1: Peripheral wall 4b2 :Bottom wall 4b3 : Corner 4b4:Bottom surface 4c:Protrusion 4d: Inner bag body 4f: Seal cylinder part 4f1: Inner self 4g: convex 4h: recessed 4k :protrusion 4m: Engagement part 4ma: Axial engagement part 4mb: Circumferential engagement part 4p: Movement suppression part 5: Mouth 5c: Open end 6: Torso 6b:Shoulder 6c: Torso body 7: Bottom 8: Mouthpiece mounting member 8a: Cap 8b: Engagement part 8c: Nozzle 8d:Discharge port 13: External preform 13a: Mouth 13b: Torso 13c: Bottom 14: Internal preform 14a: Mouth 14b: Torso 14c: Bottom 15: Preform 15a: Mouth 15b: Torso 15c: bottom 31: Cam mechanism 41: Main body components 41a: Outer cylinder 41a1:Tip 41b: Inner cylinder 41d: Upper wall 41j: Engagement protrusion 41k :Through hole 41l: Outer shell sealing area 41m: Circular storage area 41n: Inner bag sealing area 41o: opening 41p: Annular protrusion 42: Opening / closing member 42a: Outer cylinder 42b: Inner cylinder 42d: Upper wall 44: Discharge valve 46: Nozzle component 53: Airflow regulating member 53a: Annular valve C: Central axis SP1: Intermediate space SP2: External space SP3: Sealed space

Claims

1. A double-walled container comprising a container body and a mouth attachment member, The container body comprises an inner bag and an outer shell positioned to cover the inner bag. The mouth attachment member is attached to the mouth of the container body, The mouth attachment member comprises a main body member that is attached to the container body and an airflow restricting member. The main body member comprises an outer cylinder positioned outside the opening, The outer cylinder has through holes on its circumferential surface, The airflow restricting member is attached to the main body member so as to restrict the airflow through the through hole. A double container in which the airflow restricting member restricts the airflow between the intermediate space between the outer shell and the inner bag and the external space of the double container.

2. A double-walled container according to claim 1, The airflow restricting member is a double container positioned on the inner surface side of the outer cylinder.

3. A double-walled container according to claim 1, The airflow restricting member is a double-walled container, which is a valve body that changes the opening of the through-hole by deformation or displacement.

4. A double container according to claim 3, The valve body is an annular valve, A double container in which the outer circumferential surface of the annular valve and the inner circumferential surface of the outer cylinder are arranged to face each other.

5. A double-walled container according to any one of claims 1 to 4, The outer cylinder is in close contact with the outer shell at the outer shell contact portion, The inner bag is provided with a protrusion that extends from the outer shell, The outer cylinder is provided with an engaging portion that engages with an axial engaging portion provided on the protruding portion, The through hole is located between the engaging portion and the outer shell contact portion of the double container.

6. A method for manufacturing a double container according to claim 1, The container body is formed by biaxial stretch blow molding of a preform.

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