Double wall container and method for manufacturing same

Abstract

Provided is a double wall container capable of regulating the flow of air through an outside air introduction hole without increasing the dimensional accuracy of the outside air introduction hole.　According to one aspect of the present invention, provided is a double wall container including a container body. The container body is a biaxially stretched blow molded body. The container body is provided with an inner bag and an outer shell disposed so as to cover the inner bag. The container body is provided with an outside air introduction hole penetrating the outer shell, and an air flow regulation member for regulating the flow of air through the outside air introduction hole. In the air flow regulation member, at least one of the components constituting the air flow regulation member is welded or adhered to the outer shell. The double wall container according to the present invention has excellent recyclability, and thus can be suitably used in production of recycle materials.

Description

Double container and its manufacturing method

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

[0002] (First, Second and Fourth Aspects) Patent Document 1 discloses a method for producing a double-layered container by biaxially stretching blow molding.

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

[0004] WO2022 / 215598 JP 2024-018821 A

[0005] (First and second viewpoints) In the double container of Patent Document 1, an outside air inlet hole is provided in the container body, and a check valve is engaged with and attached to this outside air inlet hole, so that the compressive force applied to the outer shell is transmitted to the inner bag and the outer shell returns to its original shape when the compressive force is removed.

[0006] In order to fit the check valve into the air inlet hole, the dimensional accuracy of the air inlet hole must be extremely high, but it is not easy to increase the dimensional accuracy of the air inlet hole.

[0007] (First aspect) The first aspect of the present invention was made in consideration of the above circumstances, and provides a double container that can regulate the flow of air through an outside air inlet hole without increasing the dimensional accuracy of the outside air inlet hole.

[0008] (Second Aspect) The second aspect of the present invention has been made in view of the above circumstances, and provides a double container that can improve the dimensional accuracy of the outside air introduction hole.

[0009] (Third Viewpoint) Incidentally, the double-layered container disclosed in Patent Document 2 can be considered for use 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 an application, it is necessary to introduce outside air into the intermediate space between the outer shell and the inner bag at the barrel 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 barrel.

[0010] The third aspect of the present invention was made in consideration of the above circumstances, and provides 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.

[0011] (Fourth aspect) In the double container of Patent Document 1, an outside air inlet hole is provided in the container body, and a check valve is engaged and attached to this outside air inlet hole, thereby preventing air from leaking from the intermediate space between the outer shell and the inner bag when the outer shell is compressed, and regulating the flow of air so as to allow air to flow from the external space of the container into the intermediate space when the compression of the outer shell is released.

[0012] In the configuration of Patent Document 1, it is essential to form an outside air inlet hole in the container body with high precision, but it is not easy to form an outside air inlet hole in the container body with high precision, and it is desirable to regulate the flow of air between the intermediate space and the external space without forming an outside air inlet hole in the container body.

[0013] The fourth aspect of the present invention was made in consideration of the above circumstances, and provides a double container that can regulate the flow of air between the intermediate space and the external space without forming an external air inlet hole in the container body.

[0014] (First Aspect) According to the first aspect of the present invention, the following inventions are provided. [1] A double container comprising a container body, the container body being a biaxially stretched blow-molded product, the container body comprising an inner bag and an outer shell arranged to cover the inner bag, the container body being provided with an outside air inlet hole penetrating the outer shell and an air flow regulating member for regulating the flow of air through the outside air inlet hole, at least one of the components constituting the air flow regulating member being welded or bonded to the outer shell. [2] The double container according to [1], wherein the air flow regulating member comprises a valve body and a movable body, the movable body being configured to be movable within the space within the valve body, the valve body comprising a tubular portion having the space and a flange portion protruding radially from the tubular portion, the flange portion being welded or bonded to the outer shell. [3] The double container according to [2], wherein the tubular portion is inserted into the outside air inlet hole. [4] A double container as described in [1], wherein the air flow regulating member comprises a valve body and a moving body, the moving body being configured to be able to move within the space within the valve body, the valve body being configured by combining a first member and a second member, the first member having an opening through which the moving body can pass without deforming the first member, the second member having an air hole through which the moving body cannot pass, and the second member being welded or adhered to the first member so that the air hole is in communication with the opening, and the first member or the second member being configured by the outer shell. [5] A method for manufacturing a double-layered container, comprising a biaxially stretched blow molding step and an arrangement step, wherein in the biaxially stretched blow molding step, a preform is biaxially stretched blow molded, the preform is constructed by placing an outer preform on an inner preform, the outer preform has an outside air inlet hole at the bottom that penetrates the outer preform, the biaxially stretched blow molding is performed with the bottom supported by a bottom support mold, and in the arrangement step, after the biaxially stretched blow molding, an air flow regulating member is arranged to regulate the flow of air through the outside air inlet hole.[6] The method according to [5], wherein the container body formed by the method including the biaxial stretch blow molding step comprises an inner bag and an outer shell arranged to cover the inner bag, and the air flow regulating member is arranged by welding or adhering at least one of the components constituting the air flow regulating member to the outer shell. [7] The method according to [5] or [6], wherein the outer preform comprises an annular convex portion surrounding the outside air inlet hole, and the bottom support mold is configured to suppress extension of the annular convex portion. [8] The method according to any one of [5] to [7], wherein the air flow regulating member is a check valve, the check valve comprising a valve body and a movable body movable within a space within the valve body, and the outside air inlet hole is configured to be able to accommodate at least a portion of the valve body.

[0015] (Second Aspect) According to a second aspect of the present invention, the following inventions are provided. [1] A double container comprising a container body, the container body being a biaxially stretched blow-molded product, the container body comprising an inner bag and an outer shell arranged to cover the inner bag, first and second flange portions being provided on the outer peripheral surface of the outer shell in this order from the open end of the outer shell, and the outer shell being provided with an outside air introduction hole in an intermediate region between the first and second flange portions. [2] The double container according to [1], wherein the double container comprises an air flow restriction member that restricts the flow of air through the outside air introduction hole, the air flow restriction member being arranged in the intermediate region. [3] The double container according to [2], wherein the air flow restriction member is a check valve comprising a valve body and a movable body, the movable body being configured to be movable within a space within the valve body, and the valve body being arranged in the intermediate region. [4] The double container according to [3], wherein the valve body comprises a cylindrical portion having the space and an arm extending from the cylindrical portion, the arm having a protrusion that is inserted into a recess provided in the intermediate region. [5] The double container according to [2], wherein the air flow regulating member is a check valve comprising a valve body and a moving body, the moving body being configured to be movable within the space within the valve body, and the valve body being composed of the outer shell and the inner bag. [6] A double container comprising a container body and an air flow regulating member, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the outer shell having an outside air inlet hole, the air flow regulating member comprising a valve body and a moving body, and being a check valve configured to regulate the flow of air through the outside air inlet hole, the moving body being configured to be able to move within the space within the valve body, the valve body comprising a tubular portion having the space and an arm extending from the tubular portion, the arm having a protrusion which is inserted into a recess provided in the outer shell.[7] A double container comprising a container body and an air flow restricting member, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the outer shell having an outside air inlet hole, the air flow restricting member comprising a valve body and a movable body and a check valve configured to restrict the flow of air through the outside air inlet hole, the movable body being configured to be movable within the space within the valve body, the valve body being composed of the outer shell and the inner bag. [8] A method for manufacturing a double container comprising a biaxially stretch blow molding step, wherein the biaxially stretch blow molding step comprises biaxially stretch blow molding a preform, the preform being formed by placing an outer preform on an inner preform, the outer preform being provided with first and second flange portions in that order from an open end of the outer preform, and the outer preform being provided with an outside air inlet hole in an intermediate region between the first and second flange portions.

[0016] (Third Aspect) According to a third aspect of the present invention, the following invention is provided: [1] A double container comprising a container body, the container body comprising an inner bag and an outer shell arranged to cover the inner bag, the 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 of coming 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 disposed to cover the inner bag, the container body being provided with a cam mechanism configured to displace the inner bag in a direction away from 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 in response to rotation of the inner bag relative to the outer shell. [3] The double container according to [1] or [2], wherein the cam mechanism comprises a cam rail and a cam protrusion, the cam rail being formed by an inclined surface provided on the inner peripheral surface of the outer shell, the cam protrusion being provided on the outer peripheral surface of the inner bag, and the cam protrusion being configured to move along the cam rail in response to rotation of the inner bag relative to the outer shell, thereby displacing the inner bag. [4] The double container according to [3], 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 a state of abutment at their abutment surfaces, and when the inner bag is rotated relative to the outer shell from the abutment state, the abutment between the outer shell and the inner bag at the abutment surface is released. [5] The double container according to [3] or [4] citing [1], wherein the rotation restriction mechanism includes at least one engaging 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 towards the base. [7] The double container according to any one of [1] to [6], comprising a mouth attachment member attached to the mouth of the container body, the mouth attachment member having an outside air inlet hole communicating with the intermediate space between the outer shell and the inner bag. [8] The 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 inlet hole. [9] The 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] The method for manufacturing a double container according to any one of [1] to [9], wherein the container body is formed by biaxial stretch blow molding.

[0017] (Fourth Aspect) According to a fourth aspect of the present invention, the following invention is 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 mouth attachment member is attached to the mouth of the container body, and the mouth attachment member comprises a main body member attached to the container body and an air flow restricting member, the main body member comprises an outer tube arranged outside the mouth, the outer tube having a through hole on its circumferential surface, the air flow restricting member attached to the main body member so as to restrict the flow of air through the through hole, and the air flow restricting member restricts the flow of air between an intermediate space between the outer shell and the inner bag and an external space of the double container. [2] The double container according to [1], wherein the air flow restricting member is arranged on the inner surface of the outer tube. [3] The double container according to [1] or [2], wherein the air flow regulating member is a valve element that changes the opening of the through-hole by deformation or displacement. [4] The double container according to [3], wherein the valve element is an annular valve, and the outer peripheral surface of the annular valve is arranged so that it faces the inner peripheral surface of the outer tube. [5] The double container according to any one of [1] to [4], wherein the outer tube is in close contact with the outer shell at an outer-shell contact portion, the inner bag has a protrusion protruding from the outer shell, the outer tube has an engaging portion that engages with an axial engaging portion provided on the protrusion, and the through-hole is located between the engaging portion and the outer-shell contact portion. [6] The method for manufacturing a double container according to any one of [1] to [5], wherein the container body is formed by biaxially stretch blow molding a preform.

[0018] (First Aspect) In the double container of this aspect, the flow of air through the outside air inlet hole is restricted by joining an air flow restricting member to a portion surrounding the outside air inlet hole. With this configuration, the dimensional accuracy of the outside air inlet hole does not affect the attachment of the air flow restricting member or air leakage, so the flow of air through the outside air inlet hole can be restricted without increasing the dimensional accuracy of the outside air inlet hole.

[0019] In the double-walled container of this aspect, an air inlet hole is provided in the intermediate region between the first and second flanges of the outer shell. Since the intermediate region is hardly deformed during biaxially stretched blow molding, the dimensional accuracy of the air inlet hole can be improved.

[0020] (Third aspect) In the double container of this aspect, the rotation of the inner bag relative to the outer shell is restricted while a gap is formed 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, making it easier to introduce outside air into the intermediate space between the outer shell and the inner bag at the body of the container body.

[0021] (Fourth Aspect) In the double container of this aspect, the air flow restricting member is configured to restrict the flow of air through a through hole provided in the circumferential surface of the outer tube. With this configuration, it is possible to restrict the flow of air between the intermediate space and the external space without forming an outside air inlet hole in the container body. Furthermore, because the through hole is provided in the circumferential surface of the outer tube, it is easier for the through hole to communicate with the intermediate space than, for example, when the through hole is provided in the upper wall of the main body member.

[0022] (First Aspect) A front view of a double container 1 according to a first embodiment of this aspect. An exploded view of FIG. 1. FIGS. 3A and 3B are cross-sectional views of regions A and B in FIG. 1, respectively. A cross-sectional view showing a state in which the discharge member 43 has been separated from the state of FIG. 3A. A cross-sectional view showing a state in which the main body member 41 has been separated from the state of FIG. 4. FIG. 6A is an enlarged view of region A in FIG. 3B. FIG. 6B is an exploded view of FIG. 6A. A cross-sectional view showing a state in which the inner preform 14 and the outer preform 13 have been separated. A cross-sectional view of the preform 15 and the blow core 21. A cross-sectional view showing a state in which the preform 15 is attached to the blow core 21 and brought close to the heater 32. A cross-sectional view for explaining biaxial stretch blow molding of the preform 15. FIG. 11A is an enlarged view of region A in FIG. 10. FIG. 11B is an exploded view of FIG. 11A. A cross-sectional view of a molded body 2a obtained by biaxial stretch blow molding. FIG. 13A is a view corresponding to FIG. 6A of a double container 1 according to a second embodiment of this aspect. 13B is an exploded view of FIG. 13A. FIG. 14A is a view corresponding to FIG. 6A, showing a double container 1 according to a third embodiment of the present invention. FIG. 14B is an exploded view of FIG. 14A. FIG. 15A is a view corresponding to FIG. 6A, showing a double container 1 according to a fourth embodiment of the present invention. FIG. 15B is an exploded view of FIG. 15A. (Second Aspect) A perspective view of the double container 1 according to the first embodiment of the present invention. An exploded perspective view of the container body 2 and the air flow restriction member 53 of the double container 1 of FIG. 16. An enlarged view of the vicinity of the mouth portion 5 of FIG. 17. A longitudinal sectional view of the double container 1 of FIG. 16. An exploded view of FIG. 19. FIG. 21A is a sectional view taken along line A-A in FIG. 19. FIG. 21B is an enlarged view of region B in FIG. 21A. A perspective view showing a state in which the inner preform 14 and the outer preform 13 have been separated. A sectional view showing a state in which a preform 15 is attached to a blow core 21 and brought close to a heater 32. A sectional view for explaining biaxial stretch blow molding of a preform 15. 26A is a diagram corresponding to FIG. 19 and illustrating the double container 1 of the second embodiment of this aspect. FIG. 26A is a cross-sectional view taken along line A-A in FIG. 25. FIG. 26B is an enlarged view of region B in FIG. 26A. (Third aspect) A perspective view of the double container 1 of the first embodiment of this aspect. An exploded perspective view of the double container 1 of FIG. 27. FIG. 29A is a longitudinal cross-sectional view of the double container 1 of FIG. 27.29B is an enlarged view of region B in FIG. 29A. It is an exploded view of FIG. 29. It is an exploded perspective view of the vicinity of the mouth portion 5 of the container body 2. FIG. 32A is a cross-sectional view corresponding to FIG. 29A, showing a state after a gap 2c has been formed between the outer shell 3 and the inner bag 4. FIG. 32B is an enlarged view of region B in FIG. 32A. It is a perspective view showing a state in which the inner preform 14 and the outer preform 13 have been separated. It is a perspective view of the preform 15. (Fourth View) A perspective view of the double container 1 of the first embodiment of this view. It is an exploded view of the double container 1 of FIG. 35. It is an exploded view of the vicinity of the mouth portion 5 of the container body 2 of FIG. 36. It is a longitudinal cross-sectional view of the double container 1 of FIG. 35. It is an exploded view of FIG. 38. FIG. 40A is an end view taken along line A-A in FIG. 38. FIG. 40B is a cross-sectional view corresponding to FIG. 40A, showing a state in which the annular valve 53b has been deflected and a gap has been formed between the annular valve 53b and the outer cylinder 41a. Fig. 41A is a perspective view of the mouth portion attachment member 8 of Fig. 36 seen from another direction. Fig. 41B is an exploded view of Fig. 41A. Fig. 41B is a perspective view showing a state in which the inner preform 14 and the outer preform 13 are separated. Fig. 41B is a perspective view of a preform 15 formed by covering the inner preform 14 with the outer preform 13.

[0023] The following describes embodiments of the present invention. The various features described in the following embodiments can be combined with each other. Each feature can be an independent invention. Furthermore, elements in the following embodiments that are not defined in the claims are optional and can be omitted. Numerical values ​​disclosed in the following description may have any number of "0s" (e.g., one or two) added to the end. For example, "1.4" may be followed by one or two "0s" to make it "1.40" or "1.400." Furthermore, when drawings with subnumbers (e.g., Figures 1A and 1B) are included, a reference to the drawing without the subnumber (e.g., Figure 1) refers to all drawings with the subnumbers (e.g., Figures 1A and 1B in the above example). Furthermore, numerical values ​​in the following description may be average values ​​unless otherwise specified.

[0024] The first to fourth aspects of the present invention will be described below. The matters described in separate aspects can be combined with each other as long as it does not go against the spirit of the invention.

[0025] (First Aspect) The first aspect of the present invention will be described.

[0026] 1. First Embodiment A first embodiment of this aspect will be described with reference to FIGS.

[0027] 1-1. Configuration of the Double Container 1 <Basic Configuration> As shown in FIGS. 1 and 2 , the double container 1 of the first embodiment of this aspect includes a container body 2 and a spout attachment member 8. The double container 1 is a bottle-shaped container capable of holding beverages, seasonings, and the like. 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. Furthermore, in the following description, the "axial direction" refers to the direction in which the central axis C (shown in FIG. 2 ) of the spout 5 extends, e.g., the direction in which the inner bag 4 is pulled out of the container body 2. The "circumferential direction" refers to the rotational direction about the central axis C of the spout 5, e.g., the direction in which the inner bag 4 is rotated at the spout 5 relative to the outer shell 3. Unless otherwise specified, "clockwise" and "counterclockwise" refer to directions as viewed from the top of the double container 1.

[0028] As shown in Fig. 2, the container body 2 has a mouth 5, a body 6, and a bottom 7. The mouth 5 is a tubular (preferably cylindrical) portion having an open end 5c. The open end 5c is the open end of the container body 2 and also the open end of the inner bag 4.

[0029] 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 preferably has a larger outer diameter (in this specification, "outer diameter" means the circular equivalent diameter when the cross section is not circular) than the mouth 5. The body 6 is cylindrical, and the bottom 7 is provided at the lower end of the body 6 and closes the lower end of the body 6. The body 6 has a shoulder 6b whose outer diameter increases with increasing distance from the mouth 5. The body 6 also has a body main body 6c located closer to the bottom 7 than the shoulder 6b. The body main body 6c preferably has a shape in which the outer diameter is substantially constant toward the bottom 7 or a shape in which the diameter decreases toward the bottom 7; for example, the body main body 6c has a shape in which the outer diameter is substantially constant toward the bottom 7 or a shape in which the diameter decreases toward the bottom 7.

[0030] 3 to 6, the container body 2 includes an inner bag 4 and an outer shell 3 disposed to cover the inner bag 4. The inner bag 4 includes a protruding portion 4c protruding from the open end 3a of the outer shell 3, and the inner bag body 4d other than the protruding portion 4c is 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.

[0031] The container body 2 is a biaxially stretched blow molded article, and can be formed by biaxially stretching blow molding a preform 15, as will be described later.

[0032] The basic configuration of the double container 1 shown here also applies to other embodiments of this aspect, the second and third aspects, as long as it does not contradict the spirit thereof.

[0033] 4 and 5, the protruding portion 4c of the inner bag 4 is provided with an engaging portion 4c6 and an engaging portion 4c3 in this order from the opening end 5c side. The outer shell 3 is provided with first and second flange portions 3f1 and 3f2 in this order from the opening end 3a side.

[0034] 5 , the inner bag 4 includes 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.

[0035] The 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 edge 3a, or may be provided at a higher or lower position than the opening edge 3a. In this embodiment, the inner bag support surface 3a3 is provided at a lower position than the opening edge 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.

[0036] A cam mechanism is preferably provided between the inner bag 4 and the outer shell 3. The cam mechanism functions to displace the inner bag 4 in a direction that allows it to be removed from the container body 2 by rotating the inner bag 4 clockwise or counterclockwise relative to the outer shell 3. This cam mechanism can be configured, for example, by a ridge provided on the outer peripheral surface of the inner bag 4 and a cam rail provided on the inner peripheral 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 even easier to pull out.

[0037] <Mouth mounting member 8> The mouth mounting member 8 is a member that is attached to the mouth 5 of the container body 2. As shown in Fig. 3A, the mouth mounting member 8 includes a main body member 41 and a discharge member 43. The discharge member 43 has a discharge port 43a that communicates with the interior of the inner bag 4.

[0038] 5, an insertion hole 41h through which the protrusion 4c is inserted is provided in the main body member 41. The protrusion 4c is inserted into the insertion hole 41h.

[0039] The main body member 41 includes an inner tube 41b and a main body member seal tube 41d. The inner tube 41b has a smaller outer diameter than the main body member seal tube 41d. The main body member seal tube 41d is provided with an engaging protrusion 41d4 that axially engages with the protrusion 4c. The engaging protrusion 41d4 axially engages with the protrusion 4c (more specifically, with the engaging portion 4c3), thereby axially engaging the main body member 41 with the protrusion 4c. It is also preferable that the main body member seal tube 41d circumferentially engages with the protrusion 4c. In this case, the protrusion 4c can be rotated in conjunction with the rotation of the main body member 41. The inner tube 41b and the main body member seal tube 41d are connected to each other by a top surface 41g. An insertion hole 41h is provided in the top surface 41g.

[0040] As shown in FIG. 4 , the inner circumferential surface 41d2 of the main body member seal tube 41d and the outer circumferential surface 3g4 of the outer shell 3 at a position adjacent to the open end 3a are in close contact with each other at a contact surface 51. The contact surface 51 is preferably inclined with respect to the axial direction. This inclination angle is, for example, 0.5 to 15 degrees (7.5 degrees in this embodiment), and preferably 3 to 10 degrees. Specific examples of this inclination angle include 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 11, 12, 13, 14, and 15 degrees, and may be in a range between any two of the values ​​exemplified here.

[0041] The main body member sealing tube 41d does not engage with the outer shell 3 in a convex-concave manner. Because the main body member sealing tube 41d and the outer shell 3 are in close contact with each other, they are frictionally engaged, but the convex portions of one do not fit into the concave portions of the other. This allows the main body member sealing tube 41d to be quickly removed from the outer shell, suppressing an increase in the force required to pull out the inner bag 4. Furthermore, because the contact surface 51 is inclined to prevent undercuts, the contact at the contact surface 51 can be broken by slightly moving the main body member 41 away from the outer shell 3. This suppresses an increase in the force required to pull out the inner bag 4 due to friction at the contact surface 51.

[0042] The inner circumferential surface 41b1 of the inner cylinder 41b is in close contact with the outer circumferential surface 4c7 of the protrusion 4c. A contact surface 52 between the inner circumferential surface 41b1 of the inner cylinder 41b and the outer circumferential surface 4c7 of the protrusion 4c is preferably inclined with respect to the axial direction. This inclination angle is, for example, 0.5 to 15 degrees (6.7 degrees in this embodiment), and preferably 3 to 10 degrees. Specific examples of this inclination angle include 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 11, 12, 13, 14, and 15 degrees, and may be in a range between any two of the values ​​exemplified here.

[0043] With this configuration, the main body member 41 is in close contact with both the outer shell 3 and the inner bag 4, so that an airtight space can be formed between the outer shell 3 and the inner bag 4.

[0044] As shown in Figure 4, the discharge member 43 is attached to a tip portion 4c5 of the protrusion 4c that protrudes from the main body member 41 through an insertion hole 41h. More specifically, an engagement portion 4c6 is provided in the tip portion 4c5, and the discharge member 43 is attached to the tip portion 4c5 by engaging with the engagement portion 4c6. In this embodiment, the engagement portion 4c6 is a male thread portion 4c12 provided on the outer surface of the tip portion 4c5, and this male thread portion is threadedly engaged with a female thread portion 43b provided on the inner circumferential surface of the discharge member 43. The discharge member 43 may be attached to the tip portion 4c5 in a capping type.

[0045] As shown in FIG. 4 , the discharge member 43 includes a discharge member body 45 and an overcap 46. The discharge member body 45 includes a nozzle 45a and an engaging tube 45b. The nozzle 45a and the engaging tube 45b are connected to each other at a top surface 45c. The nozzle 45a is provided with a discharge port 45d that communicates with the interior of the inner bag 4, allowing the contents of the inner bag 4 to be discharged through the nozzle 45a and the discharge port 45d. The nozzle 45a is provided with a discharge valve 44. The discharge valve 44 is configured to allow the contents to be discharged while preventing outside air from entering the inner bag 4. The discharge port 45d can be closed using the overcap 46. When in use, the overcap 46 can be removed to open the discharge port 45d and discharge the contents.

[0046] As shown in Fig. 5, the open end 5c of the protrusion 4c has a reduced diameter portion 4c9 formed by bending a portion adjacent to the open end 5c radially inward. If the inner diameter of the reduced diameter portion 4c9 is Di and the outer diameter is Do, then Di / Do is, for example, 0.50 to 0.95 (0.70 in this embodiment), and preferably 0.76 to 0.90. Specific examples of this value include 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, and 0.95, and may be in a range between any two of the values ​​exemplified here.

[0047] If the thickness of the inner circumferential surface 4c13 of the reduced diameter portion 4c9 is T, the value of {(Do-Di) / T} is, for example, 2.5 or more (7.2 in this embodiment), and preferably 4 or more. This value is, for example, 2.5 to 15, and preferably 4 to 10, and specifically, for example, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 11, 12, 13, 14, or 15, or may be in a range between any two of the values ​​exemplified here. The thickness T is, for example, 0.40 to 1.20 mm, and preferably 0.50 to 1.00 mm. Specific examples of this thickness include 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, and 1.20 mm, and may be in a range between any two of the values ​​exemplified here.

[0048] A seal member 48 is welded to the upper surface 4c10 of the reduced diameter portion 4c9. In one example, the seal member 48 is configured by laminating a sealant layer and a gas barrier layer, with the sealant layer welded to the upper surface 4c10. In one example, the gas barrier layer is an aluminum layer. By welding the seal member 48 thus configured to the upper surface 4c10 and closing the opening 4c11 of the open end 5c, deterioration of the contents within the inner bag 4 is suppressed. At the start of use, the discharge member 43 can be temporarily removed, the seal member 48 can be peeled off, and then the discharge member 43 can be reattached to the tip portion 4c5.

[0049] The upper surface 4c10 of the reduced diameter portion 4c9 is preferably inclined so as to rise toward the radial center of the protruding portion 4c (i.e., toward the outside of the protruding portion 4c in the axial direction). The inclination angle of the upper surface 4c10 with respect to the horizontal plane (i.e., a plane perpendicular to the axial direction) is, for example, 1 to 25 degrees (12 degrees in this embodiment), and preferably 5 to 20 degrees. When this inclination angle is within the above range, welding defects of the seal member 48 are unlikely to occur. Specifically, this inclination angle may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 degrees, or may be in a range between any two of the values ​​exemplified here.

[0050] 3B and 6, the container body 2 is provided with an outside air introduction hole 3h penetrating the outer shell 3, and an air flow regulation member 53 that regulates the flow of air through the outside air introduction hole 3h. The outside air introduction hole 3h is preferably provided in the bottom 7, and preferably in the center of the bottom 7. Providing the outside air introduction hole 3h in this position not only makes the air flow regulation member 53 less noticeable, resulting in an excellent appearance, but also has the advantage that when an outside air introduction hole 13g (shown in FIG. 7) that serves as the outside air introduction hole 3h is provided in the outer preform 13, the outside air introduction hole 13g is less likely to deform during biaxial stretch blow molding.

[0051] As shown in FIG. 6A , the air flow restriction member 53 is welded or glued to the outer shell 3 at the joint 53a. Attaching the air flow restriction member 53 to the air inlet 3h by a method such as engagement requires extremely high dimensional accuracy of the air inlet 3h, which is not easy to achieve. In contrast, in this embodiment, the air flow restriction member 53 is welded or glued to the outer shell 3. This allows the air flow restriction member 53 to be positioned at a desired location to restrict the flow of air through the air inlet 3h without increasing the dimensional accuracy of the air inlet 3h. The joint 53a is preferably provided around the entire circumference of the air inlet 3h. In this case, air leakage from gaps between the air flow restriction member 53 and the outer shell 3 is suppressed.

[0052] The air flow restricting member 53 is configured to allow air to flow out of the intermediate space between the outer shell 3 and the inner bag 4 to an extent that, when the outer shell 3 is pressed from the outside of the container body 2 to discharge the contents of the inner bag 4, the pressure in the intermediate space between the outer shell 3 and the inner bag 4 increases to the extent that the contents can be easily discharged, or to prevent air from flowing out. When pressure is stopped, the air flow restricting 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.

[0053] Examples of the air flow restricting member 53 include a check valve 9 that restricts the flow of air as the moving body moves, and a ventilation membrane that allows a small amount of air flow. The ventilation membrane may be, for example, a microporous membrane made primarily of polytetrafluoroethylene (PTFE), and the microporous membrane may be a composite of a nonwoven fabric and a polyethylene terephthalate (PET) mesh.

[0054] The check valve 9 has the function of preventing air from flowing out through the outside air introduction hole 3h while allowing air to flow in through the outside air introduction hole 3h. The check valve 9 includes a valve body 9a and a movable body 9b. The movable body 9b is configured to be movable within a space 9a3 within the valve body 9a. The space 9a3 includes a first opening 9a1 on the outside space side and a second opening 9a2 on the intermediate space side. The valve body 9a includes a first abutment portion 9a4 that abuts against the movable body 9b when it moves toward the outside space, and a second abutment portion 9a5 that abuts against the movable body 9b when it moves toward the intermediate space. When the movable body 9b abuts against the first abutment portion 9a4, air is prevented from flowing out through the openings 9a1 and 9a2. When the movable body 9b is separated from the first contact portion 9a4 (for example, when the movable body 9b is in contact with the second contact portion 9a5), air is allowed to flow in through the openings 9a1 and 9a2.

[0055] The outside air introduction hole 3h is configured to accommodate at least a portion of the valve body 9a. The valve body 9a includes a base 9a6 and a tip 9a7 protruding from the base 9a6. The tip 9a7 has a smaller outer diameter than the base 9a6, and a flat portion 9a8 is provided at the boundary between the base 9a6 and the tip 9a7. The outside air introduction hole 3h includes, in order from the outer surface 3i side of the outer shell 3, a base 3h1 and a tip 3h2, and a flat portion 3h3 is provided at the boundary between the base 3h1 and the tip 3h2. The base 9a6 and the tip 9a7 are accommodated within the base 3h1 and the tip 3h2, respectively. The valve body 9a is welded or bonded to the outer shell 3. It is preferable that at least one (preferably two or three) of the base 9a6, the tip 9a7, and the flat portion 9a8 of the valve body 9a be welded or bonded. Furthermore, it is preferable that the valve body 9a be welded or bonded at least at the flat portion 9a8. In this case, the flat portion 9a8 of the valve body 9a can be easily pressed against the flat portion 3h3 for welding or bonding. Welding is preferable to bonding because it does not require adhesive. Furthermore, ultrasonic welding is preferable for welding. As described above, in this embodiment, the valve body 9a, which is one of the components constituting the air flow restricting member 53, is welded or bonded to the outer shell 3. It is preferable that the tip surface 9a10 of the valve body 9a is flat. Furthermore, when the valve body 9a is welded or bonded to the outer shell 3, it is preferable that the valve body 9a does not protrude inward from the inner surface of the outer shell 3, and it is preferable that the tip surface 9a10 and the inner surface of the outer shell 3 are flush with each other. In this case, damage to the inner bag 4 by the valve body 9a is suppressed.

[0056] <Uses of the Double Container 1> In this embodiment, the opening attachment member 8 is provided with a discharge valve 44, which causes the inner bag 4 to shrink as the contents of the inner bag 4 are discharged. Furthermore, an outside air inlet hole 3h is provided through the outer shell 3, allowing the inner bag 4 to separate from the outer shell 3 and shrink as the contents are discharged, creating a peelable container. Furthermore, an air flow restriction member 53 is provided to restrict the flow of air through the outside air inlet hole 3h, so that when the outer shell 3 is compressed, the pressure in the intermediate space increases, 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 restore its original shape. Therefore, this embodiment makes it possible to create a squeeze-type peelable container.

[0057] <Removing the inner bag 4> Because the main body member 41 is axially engaged with the protrusion 4c, the inner bag 4 can be removed from the container body 2 by pulling the main body member 41. Furthermore, if the main body member 41 is also circumferentially engaged with the protrusion 4c, the inner bag 4 can be twisted and reduced in diameter by rotating the main body member 41. Since the inner bag 4 is less likely to rotate relative to the outer shell 3 at the body 6 and bottom 7 than at the mouth 5, rotating the inner bag 4 relative to the outer shell 3 at the mouth 5 twists the inner bag 4 and reduces its diameter. This reduces the force required to remove the inner bag 4.

[0058] Furthermore, if a cam mechanism is provided between the inner bag 4 and the outer shell 3, the inner bag 4 is configured to move in a direction that causes it to come out of the container body 2 as it rotates. With this configuration, by rotating the main body member 41, the inner bag 4 can be moved in a direction that causes it to come out of the container body 2 while twisting, and then by pulling the main body member 41, the inner bag 4 can be pulled out of the container body 2. The cam mechanism is preferably provided in the opening 5. In the cam mechanism, it is preferable that the inner bag 4 and the outer shell 3 come into contact with each other.

[0059] 1-2. Manufacturing method of double container 1 The container body 2 can be manufactured by a method including a biaxially stretched blow molding process and a cutting process. In addition, after biaxially stretched blow molding, a placement process can be performed in which the air flow restriction member 53 is placed. Furthermore, a process can be performed in which the mouth attachment member 8 is attached to the container body 2. The double container 1 can be manufactured by the above processes.

[0060] 7 and 8, 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.

[0061] As shown in Fig. 7, the inner preform 14 is cylindrical with a bottom and includes a mouth 14a, a body 14b, and a bottom 14c. The bottom 14c is provided so as to close the lower end of the body 14b. A protrusion 14d is provided on the mouth 14a. As shown in Fig. 8, the protrusion 14d is a portion of the preform 15 that protrudes from the open end 13f of the outer preform 13. The protrusion 14d does not deform during molding and remains in its original shape to become the protrusion 4c.

[0062] 7 and 8, the inner preform 14 has a cylindrical extension 14f extending from a portion 14e corresponding to the open end 5c of the container body 2. The extension 14f is provided on the protruding portion 14d. The extension 14f has, in order from the open end 14g side of the inner preform 14, an expanded diameter portion 14h and a reduced diameter portion 14i. The reduced diameter portion 14i has an inner diameter smaller than that of the expanded diameter portion 14h. The expanded diameter portion 14h and the reduced diameter portion 14i are connected by an inclined portion 14j.

[0063] 7, 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 to close the lower end of the body 13b. The bottom 13c of the outer preform 13 is provided with an outside air introduction hole 13g and an annular protrusion 13h that surrounds the outside air introduction hole 13g. The shape of the outside air introduction hole 13g remains almost unchanged during biaxial stretch blow molding, and has substantially the same shape as the outside air introduction hole 3h.

[0064] As shown in Figure 8, the preform 15 can be formed by covering the inner preform 14 with the outer preform 13. The mouth portions 13a, 14a become the mouth portion 15a of the preform 15, the body portions 13b, 14b become the body portion 15b of the preform 15, and the bottom portions 13c, 14c become the bottom portion 15c of the preform 15. During biaxial stretch blow molding, the portion closer to the bottom portion 15c than the flange 13d (the body portion 15b and the bottom portion 15c) is mainly stretched. 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 does not contradict the intent thereof.

[0065] 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 (e.g., PET) or polyolefin (e.g., polypropylene, polyethylene). 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. Direct blow molding has the advantage that it is easier to make thinner and multi-layered parts than injection molding.

[0066] 8 to 10, the biaxially stretched blow molding process will be described. In the biaxially stretched blow molding process, the preform 15 is attached to the blow core 21 so that the insertion portion 21b of the blow core 21 is positioned within the preform 15, and the preform 15 is then biaxially stretched and blow molded.

[0067] In one example, the biaxial stretch blow molding process includes a mounting step, a heating step, and a stretching step. Each step will be described below.

[0068] <Attachment Process> In the attachment process, as shown in Figures 8 and 9, the preform 15 is attached to the blow core 21 so that the insertion portion 21b of the blow core 21 is positioned within the preform 15 (more specifically, the extension portion 14f). The blow core 21 includes a base portion 21a, an insertion portion 21b, and a through hole 21c. The insertion portion 21b is provided so as to protrude from the base portion 21a. The insertion portion 21b is tapered, making it easier to insert the insertion portion 21b into the extension portion 14f of the preform 15.

[0069] The insertion portion 21b has, in order from the distal end 21g side, a reduced diameter portion 21h, an inclined portion 21i, and an expanded diameter portion 21j. The reduced diameter portion 21h has a smaller outer diameter than the expanded diameter portion 21j. The expanded diameter portion 21j and the reduced diameter portion 21h are connected by the inclined portion 21i. The reduced diameter portion 21h, the inclined portion 21i, and the expanded diameter portion 21j have shapes corresponding to the reduced diameter portion 14i, the inclined portion 14j, and the expanded diameter portion 14h, respectively, and preferably have complementary shapes. As shown in Figures 8 and 9, when the insertion portion 21b is inserted into the extension portion 14f, it is preferable that at least one (preferably two or three) of the reduced diameter portion 21h, the inclined portion 21i, and the expanded diameter portion 21j abut or come into close proximity to the reduced diameter portion 14i, the inclined portion 14j, and the expanded diameter portion 14h, respectively. For example, the inclined portion 21i can be in contact with the inclined portion 14j, the reduced diameter portion 21h can be in contact with or close to the reduced diameter portion 14i, and the expanded diameter portion 21j can be in contact with or close to the expanded diameter portion 14h. By providing the extension portion 14f as in this embodiment, it is possible to make the inner circumferential surface of the inner preform 14 and the outer circumferential surface of the insertion portion 21b face each other over a wide area, and by making the inner circumferential surface of the extension portion 14f in contact with or close to the outer circumferential surface of the insertion portion 21b, leakage of air from the gap between the inner preform 14 and the blow core 21 during biaxial stretch blow molding is suppressed.

[0070] Furthermore, the preform 15 is preferably transported while being supported by the blow core 21, and by providing the extension 14f, the preform 15 can be stably supported by the blow core 21. On the other hand, if the inner preform 14 does not have the extension 14f, the preform 15 is supported by the blow core 21 at the inner peripheral surface, which has a small area, and the supporting state is likely to become unstable.

[0071] <Heating Process> The heating process can be performed using a heating device 35 shown in FIG. 9. In the heating process, the preform 15 is heated and softened to a softened state. In one example, the heating process can be performed by placing the preform 15 in proximity to a heater 32 while the preform 15 is attached to a blow core 21, as shown in FIG. 9. The heating process is performed by heating the body portion 15b and the bottom portion 15c while the flange 13d provided on the preform 15 is covered with a heat shield 33. This softens the body portion 15b and the bottom portion 15c. On the other hand, the flange 13d and the mouth portion 15a covered with the heat shield 33 receive little or no heat from the heater 32 and are not softened. In one example, the preform 15 can be heated while being rotated. In one example, the heater 32 is composed of multiple rod-shaped heaters arranged along the side of the preform 15, but other configurations are also possible.

[0072] <Stretching Step> The stretching step can be performed using a blow molding device 36 shown in Fig. 10. In the stretching step, the softened preform 15 is stretched. In one example, the stretching step includes a first stretching step and a second stretching step.

[0073] First Stretching Step In the first stretching step, the preform 15 is stretched along a first axial direction (i.e., the vertical direction). The first axis is, for example, a direction parallel to the central axis C of the mouth portion 5, i.e., the vertical direction in FIG. 10 . In one example, as shown in FIG. 10 , this step can be performed by setting the heated preform 15 in a molding die 23, supporting the bottom 15c of the preform 15 with a bottom support die 22, and then pressing a stretch rod 25 inserted through a through hole 21c in the blow core 21 against the inner bottom surface of the inner preform 14 to stretch it. At this time, it is preferable to retract the bottom support die 22 in synchronization with the extension of the stretch rod 25. This allows the preform 15 to be stably stretched.

[0074] The preform 15 can be transferred from the heating device 35 to the blow molding device 36 while supported by the blow core 21. The molding die 23 is composed of a split mold that can be opened and closed, and includes a cavity surface 23a corresponding to the outer surface shape of the container body 2, and a flange accommodating portion 23b that can accommodate the flange 13d. The preform 15 is set in the molding die 23 so that the flange 13d is disposed within the flange accommodating portion 23b. The first stretching step can be performed in a state where the flange 13d is pressed against an opposing surface 23c that faces the flange 13d in the first axial direction.

[0075] Second Stretching Step In the second stretching step, after the first stretching step, air is blown into the inner preform 14 to stretch (i.e., expand) the preform 15 in the second axial direction (i.e., the lateral direction) and shape it into the shape of the cavity surface 23a. Air can be blown in through the through holes 21c provided in the blow core 21. In this embodiment, the provision of the extensions 14f prevents air from leaking from the gap between the inner preform 14 and the blow core 21, thereby preventing molding defects.

[0076] By the above steps, a molded body 2a having a structure in which the extension 14f is connected to the container body 2 as shown in FIG. 12 is obtained.

[0077] In the method of this embodiment, as shown in FIGS. 10 and 11 , biaxial stretch blow molding is performed with the bottom 13c of the outer preform 13 supported by the bottom support mold 22, thereby suppressing deformation of the air inlet hole 13g. Furthermore, an annular convex portion 13h is provided surrounding the air inlet hole 13g, and the bottom support mold 22 is configured to suppress stretching of the annular convex portion 13h, further suppressing deformation of the air inlet hole 13g. In one example, the bottom support mold 22 has an annular convex portion 22a, which supports the bottom 13c so that the inner circumferential surface of the annular convex portion 22a is in close proximity to or abuts the outer circumferential surface of the annular convex portion 13h. With this configuration, deformation of the annular convex portion 13h can be suppressed by bringing the inner circumferential surface of the annular convex portion 22a into close proximity to or abutting the outer circumferential surface of the annular convex portion 13h. Furthermore, the bottom support mold 22 has a protrusion 22b that is inserted into the air inlet hole 13g. Since the temperature of the protrusions 22b is usually lower than that of the bottom portion 13c, deformation of the air introduction holes 13g is further suppressed by bringing the protrusions 22b into contact with the inner surface of the air introduction holes 13g.

[0078] 1-2-3. Cutting Step In the cutting step, after the biaxially stretch blow molding step, the extension 14f is cut off along the dotted line 47 as shown in Fig. 12. This results in the container body 2 having the structure shown in Fig. 5. After the cutting step, the opening end 5c is provided with a reduced diameter portion 4c9 formed by bending a portion adjacent to the opening end 5c radially inward. The outside air introduction hole 13g of the outer preform 13 becomes the outside air introduction hole 3h of the outer shell 3.

[0079] 1-2-4. Placement Process In the placement process, as shown in FIG. 6 , an air flow restriction member 53 is placed after biaxial stretch blow molding to restrict the flow of air through the outside air introduction hole 3h. In the method of this embodiment, deformation of the outside air introduction hole 13g is suppressed, and the shape of the outside air introduction hole 13g and the shape of the outside air introduction hole 3h are approximately the same, thereby suppressing problems associated with deformation of the outside air introduction hole 13g. In one example, as shown in FIG. 6 , the air flow restriction member 53 is a check valve 9. This check valve 9 includes a valve body 9a and a movable body 9b that can move within a space 9a3 within the valve body 9a, and the outside air introduction hole 3h is configured to accommodate at least a portion of the valve body 9a. According to the method of this embodiment, deformation of the outside air introduction hole 13g during biaxial stretch blow molding is suppressed, thereby suppressing problems that may occur when inserting the valve body 9a into the outside air introduction hole 3h.

[0080] Preferably, the container body 2 formed by a method including a biaxial stretch blow molding process includes an inner bag 4 and an outer shell 3 arranged to cover the inner bag 4, and the air flow restricting member 53 is arranged by welding or adhering at least one of the components constituting the air flow restricting member 53 to the outer shell 3. In this case, the air flow restricting member 53 is arranged more stably. In one example, the valve body 9a is welded or adhered to the outer shell 3 at the joint 53a. In this and the second embodiment, the air flow restricting member 53 is arranged by attaching a completed check valve 9. However, as in the third and fourth embodiments, the outer shell 3 may constitute a part of the check valve 9, and the air flow restricting member 53 may be arranged by welding or adhering other components of the check valve 9 to the outer shell 3 to complete the check valve 9. Note that, in the invention from the viewpoint of being able to suppress deformation of the outside air introduction hole 13g during biaxial stretch blow molding, the above-mentioned welding or adhering is not essential. In this case, the air flow restricting member 53 may be attached to the outside air introduction hole 3h by press-fitting or engagement.

[0081] 1-2-5. Content Filling Process and Sealing Process After the cutting process, the content filling process and sealing process may be performed in this order. In the content filling process, the container body 2 is filled with the content. Examples of the content include mayonnaise and sauce. In the sealing process, a sealing member 48 is welded to the upper surface 4c10 of the reduced diameter portion 4c9 to close the opening 4c11 at the open end 5c. This prevents the content from deteriorating.

[0082] 2. Second Embodiment A second embodiment of this aspect will be described using FIG. 13 . This embodiment is similar to the first embodiment, and the details described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs from the first embodiment mainly in the configuration of the air flow restriction member 53. The following description will focus on these differences.

[0083] In this embodiment, the valve body 9a includes a cylindrical portion 9c having a space 9a3 and a flange portion 9d protruding radially from the cylindrical portion 9c. The flange portion 9d is welded or glued to the outer shell 3 at a joint portion 53a. With this configuration, if the outside air introduction hole 3h is smaller than the flange portion 9d, the valve body 9a can be welded or glued to the outer shell 3. In this embodiment, the flange portion 9d of the valve body 9a, which is one of the components constituting the air flow restriction member 53, is welded or glued to the outer shell 3.

[0084] The cylindrical portion 9c is preferably inserted into the outside air introduction hole 3h. In this case, there is an advantage that the cylindrical portion 9c does not protrude outward from the flange portion 9d. The outside air introduction hole 3h only needs to be sufficiently large compared to the outer shape of the cylindrical portion 9c, and there is no need to increase the dimensional accuracy of the outside air introduction hole 3h. Such an outside air introduction hole 3h may be formed after biaxial stretch blow molding of the container body 2, or may originate from the outside air introduction hole 13g provided in the outer preform 13. The outside air introduction hole 13g of the outer preform 13 is prone to deformation during biaxial stretch blow molding, but in this embodiment, the dimensional accuracy of the outside air introduction hole 3h does not need to be high, so deformation during biaxial stretch blow molding does not pose a problem.

[0085] 3. Third Embodiment A third embodiment of this aspect will be described with reference to FIG. 14 . This embodiment is similar to the first embodiment, and the details described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs from the first embodiment mainly in the configuration of the air flow restriction member 53. The following description will focus on these differences.

[0086] In this embodiment, the air flow restriction member 53 is a check valve 9 and includes a valve body 9a and a movable body 9b. The valve body 9a is configured by combining a first member 9aa and a second member 9ab. The first member 9aa has an opening 9a9 through which the movable body 9b can pass without deforming the first member 9aa. The second member 9ab has an air vent 9ab1 through which the movable body 9b cannot pass, and is welded or bonded to the first member 9aa at a joint 53a so that the air vent 9ab1 communicates with the opening 9a9. The first member 9aa is configured as the outer shell 3. Therefore, in this embodiment, the second member 9ab, which is one of the members configuring the air flow restriction member 53, is welded or bonded to the outer shell 3.

[0087] That is, in this embodiment, the portion of the outer shell 3 that includes the outside air introduction hole 3h is cylindrical and functions as the first member 9aa. The movable body 9b can be inserted into the space 9a3 of the first member 9aa through the opening 9a9. Since no force is applied to either the first member 9aa or the movable body 9b when the movable body 9b is inserted, deformation of the first member 9aa and the movable body 9b is suppressed. After the second member 9ab is welded or bonded to the first member 9aa (i.e., the outer shell 3), the movable body 9b is prevented from separating from the space 9a3. Furthermore, outside air can be introduced into the intermediate space through the ventilation hole 9ab1. Furthermore, the second member 9ab is provided with a first abutment portion 9a4.

[0088] In the method of this embodiment, the first abutment portion 9a4, which requires high dimensional accuracy, is provided on the second member 9ab, which is separate from the outer shell 3, so that it is possible to regulate the flow of air through the outside air introduction hole 3h without increasing the dimensional accuracy of the outside air introduction hole 3h.

[0089] 4. Fourth Embodiment A fourth embodiment of this aspect will be described with reference to FIG. 15 . This embodiment is similar to the third embodiment, and the details described in the third embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the third embodiment. This embodiment differs mainly from the third embodiment in the configuration of the air flow restriction member 53. The following description will focus on these differences.

[0090] In the third embodiment, the first member 9aa is formed by the outer shell 3, but in the present embodiment, the second member 9ab is formed by the outer shell 3. Therefore, in the present embodiment, the first member 9aa, which is one of the members forming the air flow restricting member 53, is welded or glued to the outer shell 3.

[0091] As described above, in this embodiment, the portion of the outer shell 3 including the outside air introduction hole 3h functions as the second member 9ab. After the second member 9ab, which is formed by the outer shell 3, is welded or bonded to the first member 9aa at the joint 53a, the movable body 9b is prevented from separating from the space 9a3. Furthermore, outside air can be introduced into the intermediate space through the air vent 9ab1. Furthermore, the first member 9aa is provided with a first abutment portion 9a4. The first member 9aa preferably includes a cylindrical portion 9c having the space 9a3 and a flange portion 9d protruding radially from the cylindrical portion 9c, and the flange portion 9d is preferably welded or bonded. In this case, the first member 9aa is stably welded or bonded.

[0092] In the method of this embodiment, the first abutment portion 9a4, which requires high dimensional accuracy, is provided on the first member 9aa, which is separate from the outer shell 3, so that it is possible to regulate the flow of air through the outside air inlet hole 3h without increasing the dimensional accuracy of the outside air inlet hole 3h.

[0093] 5. Other Embodiments The shape of the mouth 5 of the container body 2 is not particularly limited and may be a shape other than that shown in the above embodiment. The extension 14f can be omitted if it is not required, in which case the cutting step can also be omitted. Furthermore, the content filling step and the sealing step can also be omitted if they are not required.

[0094] (Second Aspect) The second aspect of the present invention will be described below. The contents described in the first aspect can also be applied to this aspect as long as they are not contrary to the spirit of the first aspect.

[0095] 1. First Embodiment A double container according to a first embodiment of this aspect will be described with reference to FIGS.

[0096] 1-1. Configuration of Double Container 1 As shown in FIG. 16, the double container 1 of the first embodiment of this aspect comprises a container body 2, a spout mounting member 8, and an air flow restricting member 53.

[0097] <Basic Structure of Container Body 2> As shown in Figs. 17 and 18, the mouth 5 of the container body 2 is provided with an engaging portion 4m to which the mouth attachment member 8 can be attached.

[0098] As shown in FIG. 20, the container body 2 includes an inner bag 4 and an outer shell 3 disposed to cover the inner bag 4 .

[0099] The container body 2 is a biaxially stretched blow molded article, and can be formed by biaxially stretching blow molding a preform 15, as will be described later.

[0100] <Detailed Structure of Outer Shell 3 and Inner Bag 4> As shown in Figure 20, 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.

[0101] The 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 base surface 3a1 of the opening end 3a, or may be provided at a higher or lower position than the base surface 3a1. In this embodiment, the inner bag support surface 3a3 is provided at a lower position than the base surface 3a1. Therefore, a portion of the second tube 4b is disposed inside the outer shell 3, and the remainder is disposed outside the outer shell 3. An annular protrusion 3a2 is provided on the base surface 3a1.

[0102] By bringing the lower surface 4b4 into close contact with the inner bag support surface 3a3, air leakage from the gap between the inner bag 4 and the outer shell 3 is suppressed, and the intermediate space between the inner bag 4 and the outer shell 3 can be made into a sealed space. Note that additional sealing means may be employed to more reliably suppress air leakage from the gap between the inner bag 4 and the outer shell 3. Examples of additional sealing means include a means for bringing the mouth attachment member 8 into close contact with each of the outer shell 3 and the inner bag 4, and a means for bringing the outer shell 3 and the inner bag 4 into close contact via an elastomer.

[0103] A cam mechanism 31 is preferably provided between the inner bag 4 and the outer shell 3. The cam mechanism 31 functions to displace the inner bag 4 in a direction away from the container body 2 by rotating the inner bag 4 clockwise or counterclockwise relative to the outer shell 3. As shown in FIG. 21 , the cam mechanism 31 can be configured, for example, with a ridge 4g on the outer peripheral surface of the inner bag 4 and a cam rail 3l on the inner peripheral 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 contracted in diameter, making it easier to pull out. The cam rail 3l is provided with an engaging ridge 3m arranged to restrict the movement of the ridge 4g, thereby preventing the inner bag 4 from accidentally rotating. The cam mechanism 31 is preferably provided in a position that does not interfere with the air inlet 3h. The cam mechanism 31 is also preferably provided in the intermediate region 3n to prevent deformation during biaxial stretch blow molding. Therefore, it is preferable that the cam mechanism 31 is provided in a position in the intermediate region 3n that does not interfere with the outside air introduction hole 3h. It is preferable that the inner bag 4 and the outer shell 3 come into contact with each other at the cam mechanism 31.

[0104] 18 and 20, first and second flange portions 3f1, 3f2 are provided on the outer peripheral surface of the outer shell 3 in this order from the opening end 3a of the outer shell 3. The first flange portion 3f1 is provided adjacent to the opening end 3a. The outer shell 3 is provided with an air introduction hole 3h in an intermediate region 3n between the first and second flange portions 3f1, 3f2. Because the intermediate region 3n is hardly deformed during biaxial stretch blow molding, the dimensional accuracy of the air introduction hole 3h can be improved.

[0105] 20, the length L between the first and second flange portions 3f1, 3f2 in the axial direction is, for example, 3 to 9 mm, and preferably 4 to 7 mm (5 mm in this embodiment).Specific examples of the length L7 are 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, and 9.0 mm, and may be in a range between any two of the values ​​exemplified here.

[0106] 16 and 19, the container body 2 is provided with an air flow restriction member 53 that restricts the flow of air through the outside air introduction hole 3h. The air flow restriction member 53 is disposed in the intermediate region 3n. This makes it possible to restrict the flow of air through the outside air introduction hole 3h without providing an air flow restriction member on the mouth-mounted member 8.

[0107] The air flow restricting member 53 is configured to allow air to flow out of the intermediate space between the outer shell 3 and the inner bag 4 to an extent that, when the outer shell 3 is pressed from the outside of the container body 2 to discharge the contents of the inner bag 4, the pressure in the intermediate space between the outer shell 3 and the inner bag 4 increases to the extent that the contents can be easily discharged, or to prevent air from flowing out. When pressure is stopped, the air flow restricting 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.

[0108] Examples of the air flow restricting member 53 include a check valve 9 that restricts the flow of air as the moving object moves, and a ventilation membrane that allows a small amount of air to flow. The ventilation 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 disposing the air flow restricting member 53 in the intermediate region 3n is not limited and may be any of engagement, press-fitting, welding, adhesion, etc.

[0109] The check valve 9 functions to prevent air from flowing out through the outside air introduction hole 3h while allowing air to flow in through the outside air introduction hole 3h. As shown in FIG. 21B , the check valve 9 includes a valve body 9a and a movable body 9b. The movable body 9b is configured to be movable within a space 9a3 within the valve body 9a. The valve body 9a is attached to the intermediate region 3n. The space 9a3 includes a first opening 9a1 on the exterior space side and a second opening 9a2 on the intermediate space side. The valve body 9a includes a first abutment portion 9a4 that abuts against the movable body 9b when it moves toward the exterior space and a second abutment portion 9a5 that abuts against the movable body 9b when it moves toward the intermediate space. When the movable body 9b abuts against the first abutment portion 9a4, air is prevented from flowing out through the outside air introduction hole 3h. When the movable body 9b is in contact with the second contact portion 9a5, air is allowed to flow in through the outside air introduction hole 3h.

[0110] In this embodiment, the valve body 9a includes a cylindrical portion 9c having a space 9a3 and an arm 9f extending from the cylindrical portion 9c. The arm 9f is provided with a protrusion 9f1. The protrusion 9f1 is inserted into a recess 3j provided in the intermediate region 3n. This stably positions the valve body 9a in the intermediate region 3n. The protrusion 9f1 is provided with a claw portion 9f2, and the recess 3j is provided with an engaging protrusion 3j1 that engages with the claw portion 9f2. The engagement of the claw portion 9f2 with the engaging protrusion 3j1 prevents the arm 9f from coming off the recess 3j. The valve body 9a may be positioned in the intermediate region 3n by press-fitting, welding, adhesive bonding, or the like. Preferably, the valve body 9a includes a pair of arms 9f extending from the cylindrical portion 9c, and each of the pair of arms 9f is provided with a protrusion 9f1. Note that, from the perspective of the configuration for attaching the valve body 9a to the outer shell 3, the valve body 9a may be attached to any portion of the outer shell 3. In this case, the protrusion 9f1 of the arm 9f is inserted into a recess 3j provided at an arbitrary position on the outer shell 3.

[0111] In this embodiment, the valve body 9a is constructed as a single unit, but the valve body 9a may also be constructed by combining an attachment member attached to the intermediate region 3n with the outer shell 3. In this case, it is preferable that the attachment member be provided with a first opening 9a1 and a first abutment portion 9a4, and that the outer shell 3 be provided with a second opening 9a2 and a second abutment portion 9a5. The attachment member can be attached to the intermediate region 3n by engagement, press-fitting, welding, adhesive, or the like.

[0112] <Configuration of spout attachment member 8> The spout attachment member 8 is a member that is attached to the spout 5 of the container body 2. In this embodiment, the spout attachment member 8 is a cap 8a, but it may be another member such as a pump. As shown in Figure 20, the spout attachment member 8 has an engaging portion 8b that can engage with the engaging portion 4m. When the engaging portion 8b engages with the engaging portion 4m, the spout attachment member 8 axially engages with the spout 5 (preferably the protruding portion 4c) of the inner bag 4.

[0113] The spout attachment 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. 18, the inner bag 4 is provided with a circumferential engagement portion 4mb at a position farther from the opening edge 5c than the engagement portion 4m, and the spout attachment member 8 circumferentially engages with the spout 5 of the inner bag 4 at the circumferential engagement portion 4mb. The circumferential engagement portion 4mb preferably has a plurality of engagement protrusions 4c2 spaced apart along the circumferential direction, and when the engagement portion 8b is pressed against the engagement protrusions 4c2, the engagement portion 8b and the engagement protrusions 4c2 engage with each other in the circumferential direction.

[0114] 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.

[0115] The cap 8a preferably includes a cap body 41A and an overcap 42. The cap body 41A 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.

[0116] The cap body 41A includes an outer tube 41a, an inner tube 41b, a nozzle 8c, and an upper wall 41e. The inner tube 41b is disposed inside the outer tube 41a. The outer tube 41a and inner tube 41b are connected via the upper wall 41e. The nozzle 8c is disposed above the upper wall 41e. A flow hole 41i is provided in the upper wall 41e, and the flow passage between the inner tube 41b and the nozzle 8c is connected through the flow hole 41i. The tip of the nozzle 8c serves as the discharge port 8d. The inner tube 41b is inserted into the protruding portion 4c and is in close contact with the inner surface 4f1 of the cylindrical seal portion 4f. An engaging portion 8b is provided on the inner peripheral surface of the outer tube 41a. The cap body 41A is provided with a discharge valve 44. The discharge valve 44 is configured to allow the contents to be discharged while preventing 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 41e.

[0117] <Attaching the Mouth Attachment Member 8> As shown in FIG. 20 , the mouth attachment member 8 can be attached to the mouth 5 while the first flange portion 3f1 is supported. The mouth attachment member 8 is preferably a stopper type. With the first flange portion 3f1 supported, the mouth attachment member 8 is placed over the protruding portion 4c. When a downward force is applied to the mouth attachment member 8 in this state, the engaging portion 8b overcomes the engaging portion 4m, and the engaging portion 8b and the engaging portion 4m axially engage, attaching the mouth attachment member 8 to the mouth 5 (preferably the protruding portion 4c). In this embodiment, the mouth attachment member 8 may be attached to the mouth 5 (preferably the protruding portion 4c) using a screw type. The first flange portion 3f1 is provided as a support ring, and preferably does not engage with the mouth attachment member 8. The second flange portion 3f2 is too far from the open end 5c and may not fit into a device (e.g., a device conforming to the F-port standard) for attaching the mouth attachment member 8. Therefore, it is preferable to use the first flange portion 3f1 as a support ring.

[0118] 1-2. Manufacturing Method of Double Container 1 The container body 2 can be manufactured by biaxially stretching blow molding the preform 15 shown in Figures 22 and 23. After biaxially stretching blow molding, an arrangement step can be performed to arrange the air flow restriction member 53 in the intermediate region 3n. Furthermore, the double container 1 can be manufactured by attaching the mouth attachment member 8 to the container body 2.

[0119] 1-2-1 Preform 15 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.

[0120] As shown in Figure 22, the inner preform 14 is cylindrical with a bottom, and includes a mouth 14a, a body 14b, and a bottom 14c. A protrusion 14d is provided on the mouth 14a. As shown in Figures 22 and 23, the protrusion 14d is a portion of the preform 15 that protrudes from the open end 13f of the outer preform 13. The protrusion 14d does not deform during molding, and remains in its original shape to become the protrusion 4c. The bottom 14c is provided to close the lower end of the body 14b.

[0121] 22, the outer preform 13 is cylindrical and has a bottom, a mouth 13a, a body 13b, and a bottom 13c. The bottom 13c is provided to close the lower end of the body 13b. The outer preform 13 has first and second flanges 13f1, 13f2 and an outside air introduction hole 13g disposed in an intermediate region 13i therebetween. The first and second flanges 13f1, 13f2, the intermediate region 13i, and the outside air introduction hole 13g correspond to the first and second flanges 3f1, 3f2, the intermediate region 3n, and the outside air introduction hole 3h of the container body 2, respectively.

[0122] 23, a preform 15 can be formed by covering the inner preform 14 with the outer preform 13. In the preform 15, the mouth portion 14a faces the mouth portion 13a, and the body portion 14b faces the body portion 13b.

[0123] 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. In this embodiment, the portion of the second flange portion 13f2 closer to the bottom portion 15c than the lower surface 13f3 is mainly stretched during biaxial stretch blow molding. The portion of the second flange portion 13f2 closer to the opening end 15f than the lower surface 13f3 is hardly deformed during molding. With regard to the portion that is hardly deformed during biaxial stretch molding, the contents described in relation to the container body 2 can also be applied to the preform 15, as long as they are not contrary to the intent thereof.

[0124] <Materials and Manufacturing Methods of Inner Preform 14 and Outer Preform 13> The materials and manufacturing methods of the inner preform 14 and the outer preform 13 are the same as those in the first aspect.

[0125] 23 and 24, the biaxially stretched blow molding process will be described. In the biaxially stretched blow molding process, the preform 15 is attached to the blow core 21 so that the insertion portion 21b of the blow core 21 is positioned within the preform 15, and the preform 15 is then biaxially stretched and blow molded into the shape of the container body 2.

[0126] In one example, the biaxial stretch blow molding process includes a mounting step, a heating step, and a stretching step. Each step will be described below.

[0127] <Attachment Process> In the attachment process, as shown in Fig. 23 , the preform 15 is attached to the blow core 21 so that the insertion portion 21b of the blow core 21 is disposed within the preform 15. The blow core 21 includes a base portion 21a, an insertion portion 21b, and a through hole 21c. The insertion portion 21b is provided so as to protrude from the base portion 21a. The insertion portion 21b is inserted into the preform 15.

[0128] <Heating Process> The heating process can be performed using a heating device 35 shown in FIG. 23. In the heating process, the preform 15 is heated and softened to a softened state. In one example, the heating process can be performed by placing the preform 15 in close proximity to a heater 32 while the preform 15 is attached to a blow core 21, as shown in FIG. 23. The heating process is performed by covering the second flange portion 13f2 provided on the preform 15 with a heat shield 33 and heating a portion of the second flange portion 13f2 closer to the bottom 15c than the lower surface 13f3. This softens the heated portion. On the other hand, the portion of the second flange portion 13f2 closer to the opening end 15f than the lower surface 13f3 receives little or no heat from the heater 32 and is not softened. Furthermore, deformation of the intermediate region 13i between the first and second flange portions 13f1, 13f2 is further suppressed by the first and second flange portions 13f1, 13f2. Therefore, during biaxial stretch blow molding, the outside air introduction holes 13g arranged in the intermediate region 13i change shape little and become the outside air introduction holes 3h of the container body 2. In one example, the preform 15 can be heated while being rotated. Also, in one example, the heater 32 is composed of multiple rod-shaped heaters arranged along the side surface of the preform 15, but other configurations are also possible.

[0129] <Stretching step> The stretching step can be performed using a blow molding device 36 shown in Fig. 24. In the stretching step, the softened preform 15 is stretched to form the shape of the container body 2. In one example, the stretching step includes a first stretching step and a second stretching step.

[0130] <First Stretching Step> In the first stretching step, the preform 15 is stretched along a first axial direction (i.e., the vertical direction). The first axis is, for example, a direction parallel to the central axis C of the mouth portion 5, i.e., the vertical direction in FIG. 24 . In one example, as shown in FIG. 24 , this step can be performed by setting the heated preform 15 in a molding die 23, supporting the bottom 15c of the preform 15 with a bottom support die 22, and pressing a stretch rod 25 inserted through a through hole 21c in a blow core 21 against the inner bottom surface of the inner preform 14 to stretch it. At this time, it is preferable to retract the bottom support die 22 in synchronization with the extension of the stretch rod 25. This allows the preform 15 to be stably stretched.

[0131] The preform 15 can be transferred from the heating device 35 to the blow molding device 36 while supported by the blow core 21. The molding die 23 is composed of an openable and closable split mold and includes a cavity surface 23a corresponding to the outer surface shape of the container body 2 and a flange abutment surface 23d against which the lower surface 13f3 of the second flange portion 13f2 abuts. The first stretching step can be performed with the lower surface 13f3 of the second flange portion 13f2 abutting against the flange abutment surface 23d. If the second flange portion 13f2 were not present, the area closer to the bottom 15c than the lower surface of the first flange portion 13f1 would be heated, and the lower surface of the first flange portion 13f1 would be abutted against the flange abutment surface 23d for biaxial stretch blow molding, which would make the outside air introduction hole 13g more likely to deform during biaxial stretch blow molding. In this embodiment, the outside air introduction hole 13g is provided in the intermediate region 13i between the first and second flange portions 13f1, f2, thereby suppressing deformation of the outside air introduction hole 13g.

[0132] <Second Stretching Step> In the second stretching step, after the first stretching step, air is blown into the inner preform 14 to stretch (i.e., expand) the preform 15 in the second axial direction (i.e., the lateral direction) and shape it into the shape of the cavity surface 23a, thereby obtaining the container body 2 shown in Fig. 17. The air can be blown in through the through holes 21c provided in the blow core 21.

[0133] 2. Second Embodiment A second embodiment of this aspect will be described using Figures 25 and 26. This embodiment is similar to the first embodiment, and the details described in the first embodiment can also be applied to this embodiment as long as they do not contradict the spirit of the first embodiment. This embodiment differs mainly from the first embodiment in the configuration of the check valve 9. The following description will focus on these differences.

[0134] In this embodiment, the valve body 9a of the check valve 9 is composed of an outer shell 3 and an inner bag 4. The outer shell 3 has a recess 3k on its inner circumferential surface at a position communicating with the outside air introduction hole 3h. The inner bag 4 has a recess 4n on its outer circumferential surface at a position facing the outside air introduction hole 3h. The movable body 9b is disposed in a space 9a3 formed by the recess 3k and the recess 4n. Note that the space 9a3 may be formed by only the recess 3k or only the recess 4n.

[0135] The valve body 9a has a first abutment portion 9a4 that abuts against the movable body 9b when it moves toward the external space, and a second abutment portion 9a5 that abuts against the movable body 9b when it moves toward the intermediate space. When the movable body 9b abuts against the first abutment portion 9a4, the outflow of air through the outside air introduction hole 3h is suppressed. When the movable body 9b abuts against the second abutment portion 9a5, the inflow of air through the outside air introduction hole 3h is permitted.

[0136] According to this embodiment, the valve body 9 a can be mounted without using any additional components. From the viewpoint that the valve body 9 a is constituted by the outer shell 3 and the inner bag 4, it is not essential that the check valve 9 be disposed in the intermediate region 3 n, and it may be disposed in any position.

[0137] 3. Other Embodiments In the above embodiment, the air flow restricting member 53 is disposed in the intermediate region 3 n, but the air flow restricting member 53 can be disposed in any position that can restrict the flow of air through the outside air introduction hole 3 h. The air flow restricting member 53 can be disposed in the mouth-attached member 8, for example.

[0138] (Third Aspect) The third aspect of the present invention will be described below. The contents described in the first or second aspect can also be applied to this aspect as long as they are not contrary to the spirit of the first or second aspect.

[0139] 1. First Embodiment A double container according to a first embodiment of this aspect will be described with reference to FIGS.

[0140] 1-1. Configuration of Double Container 1 As shown in Figures 27 to 30, the double container 1 of the first embodiment of this aspect comprises a container body 2, a spout mounting member 8, and an air flow restriction member 53.

[0141] <Configuration of container body 2> As shown in Figure 30, the mouth 5 has an upper mouth 5a and a lower mouth 5b. The upper mouth 5a is the portion between the open end 5c of the container body 2 and the underside 5d1 of the flange 5d. The lower mouth 5b is the portion between the upper mouth 5a and the body 6. The base 5b1 of the lower mouth 5b is the portion below the underside 5d1 of the flange 5d where the outer diameter of the container body 2 begins to expand.

[0142] As shown in FIG. 30, the container body 2 includes an inner bag 4 and an outer shell 3 disposed to cover the inner bag 4 .

[0143] <Configuration of the mouth portion 5 of the outer shell 3> As shown in Figure 30, the outer peripheral surface of the outer shell 3 is provided with an expanded diameter portion 3o and a flange portion 5d, in that order from the opening end 3a of the outer shell 3. The expanded diameter portion 3o is configured 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.

[0144] The outer shell 3 has an inner tapered portion 3p in at least a part of the lower opening 5b, which is configured so that the inner diameter of the outer shell 3 narrows toward the base 5b1 of the lower opening 5b. In this case, the force required to pull out the inner bag 4 is reduced, and gap 2c is more likely to be formed.

[0145] 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 narrows toward the base 5b1. In this case, the inner tapered portion 3p is more likely to be formed.

[0146] 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 preferably each 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.

[0147] <Configuration of Cam Mechanism 31> As shown in FIG. 31 , 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 4o. The cam rail 3l is configured as 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 4o moves along the cam rail 3l, displacing the inner bag 4 in a direction away from the container body 2. As shown in FIG. 32 , 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.

[0148] A recess 3r capable of accommodating the cam protrusion 4o is provided in a portion of the cam rail 3l. Preferably, when the cam protrusion 4o is accommodated in the recess 3r, the outer shell 3 and the inner bag 4 are in abutting contact with each other at abutment surface 55, as shown in FIG. 29B . In this embodiment, the abutment surface 55 is the surface where the inner bag support surface 3a3 of the outer shell 3 abuts against the lower surface 4b4 of the inner bag 4. When the inner bag 4 is rotated relative to the outer shell 3 from this abutment state, the abutment between the outer shell 3 and the inner bag 4 at abutment surface 55 is released.

[0149] 31 , the container body 2 is provided with a rotation restricting mechanism 54. The rotation restricting 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 restricting 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.

[0150] 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 4o, restricting its movement, thereby restricting rotation of the inner bag 4. In this embodiment, the engagement protrusion 3s is provided to protrude from the upper surface of the cam rail 3l. However, for example, it may be provided to protrude from the inner peripheral surface of the outer shell 3. In this embodiment, the rotation restriction mechanism 54 includes a pair of engagement protrusions 3s spaced apart along the cam rail 3l. When the cam protrusion 4o is positioned between the pair of engagement protrusions 3s, the movement of the cam protrusion 4o in one direction and the other direction is restricted by the engagement protrusions 3s, thereby restricting bidirectional rotation of the inner bag 4. Alternatively, for example, the cam protrusion 4o may be provided with a recess that engages with the engagement protrusion 3s. In this case, one engagement protrusion 3s can restrict the movement of the cam protrusion 4o in one direction and the other direction.

[0151] In addition, in an invention in which a 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 restriction mechanism 54 can be omitted.

[0152] <Configuration of spout attachment member 8> The spout attachment member 8 is a member that is attached to the spout 5 of the container body 2. The description of the spout attachment member 8 is the same as that of the second aspect, except for the following points. As shown in Figure 30, the spout attachment member 8 has an engaging portion 8b that can engage with an engaging portion 4m provided on the spout 5 of the inner bag 4. When the engaging portion 8b engages with the engaging portion 4m, the spout attachment member 8 engages with the spout 5 (preferably the protruding portion 4c) of the inner bag 4 in the axial direction.

[0153] The spout attachment 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. 28 , the engagement portion 4m is provided with a plurality of engagement protrusions 4c2 spaced apart along the circumferential direction, and the engagement protrusions 4c2 engage with the spout attachment member 8 in the circumferential direction. The outer tube 41a of the cap body 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 enlarged diameter portion 3o). Because the spout attachment member 8 closely contacts both the outer shell 3 and the inner bag 4 in this manner, the intermediate space between the outer shell 3 and the inner bag 4 becomes a sealed space.

[0154] 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 41A (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 Figure 29, the outside air introduction hole 8h is located at a position farther from the open end 41a1 of the outer tube 41a than the abutment surface 56 between the outer tube 41a and the outer shell 3.

[0155] <Configuration of Air Flow Restricting Member 53> The mouth-mounted member 8 is preferably provided with an air flow restricting 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 restricting 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 not allow air to flow out. When pressure is stopped, the air flow restricting 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.

[0156] 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 primarily made 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-mounted member 8 is not limited, and may be any of engagement, press-fitting, welding, adhesive bonding, etc. The air flow restriction member 53 is preferably placed inside the outside air introduction hole 8h.

[0157] <Attaching the mouth attachment member 8> As shown in Figure 30, 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 with the enlarged diameter portion 3o or the flange portion 5d supported, the mouth attachment member 8 is placed over the protruding portion 4c. When a downward force is applied to the mouth attachment member 8 in this state, the engaging portion 8b moves over the engaging portion 4m, and the engaging portion 8b and the engaging portion 4m engage with each other in the axial direction, and the mouth attachment member 8 can be attached to the mouth 5 (preferably the protruding portion 4c).

[0158] <Use of Double Container 1> The description of the use of the double container 1 is the same as that of the first aspect. In addition, in this embodiment, a gap 2c is provided between the outer shell 3 and the inner bag 4, which is formed as the inner bag 4 rotates relative to the outer shell 3. Therefore, outside air can be smoothly introduced into the intermediate space in the trunk 6 of the container body 2.

[0159] <Removal of Inner Bag 4> The explanation of removing the inner bag 4 is the same as in the first aspect.

[0160] 1-2. Manufacturing Method of Double Container 1 The container body 2 can be manufactured by biaxially stretching blow molding the preform 15 shown in Figures 33 and 34. The double container 1 can also be manufactured by attaching the mouth attachment member 8 to the container body 2.

[0161] The inner preform 14 is provided with a cam protrusion 14o that becomes the cam protrusion 4o. The outer preform 13 is provided with a recess 13r that becomes the recess 3r. As shown in FIG. 34 , 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 protrusion 14o with the recess 13r. In other respects, the container body 2 can be manufactured in the same manner as in the first and second aspects.

[0162] <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 14o 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.

[0163] 2. Other Embodiments The direction in which each component is rotated relative to the other may be reversed. In the above embodiment, the inner bag 4 is displaced in a direction in which it comes out of the container body 2 when the clockwise screw is rotated in the loosening direction. However, the inner bag 4 may be displaced in a direction in which it comes out of the container body 2 when the counterclockwise screw is rotated in the loosening direction.

[0164] (Fourth Aspect) The fourth aspect of the present invention will now be described. The contents described in the first to third aspects are also applicable to this aspect as long as they are not contrary to the spirit of those aspects.

[0165] 1. First Embodiment A double container 1 according to a first embodiment of this aspect will be described with reference to FIGS.

[0166] 1-1. Configuration of double container 1 <Basic configuration> As shown in Figures 35 and 36, the double container 1 of the first embodiment of this aspect includes a container body 2 and a spout attachment member 8. The double container 1 is a bottle-shaped container that can hold beverages, seasonings, etc. The double container 1 is, for example, a squeeze-type container that is configured so that the contents in the container body 2 can be dispensed by compressing the barrel 6 of the container body 2.

[0167] As shown in FIGS. 37 to 39, the container body 2 includes an inner bag 4 and an outer shell 3 disposed to cover the inner bag 4.

[0168] <Outer shell 3 and inner bag 4> As shown in Figures 37 and 39, the protruding portion 4c of the inner bag 4 is provided with an engaging portion 4m to which the spout attachment member 8 can be attached. The engaging portion 4m includes an axial engaging portion 4ma that engages with the spout attachment member 8 in the axial direction, and a circumferential engaging portion 4mb that engages with the spout attachment member 8 in the circumferential direction. The circumferential engaging portion 4mb can be omitted if not required. The outer shell 3 is provided with first and second flange portions 3f1, 3f2 in this order from the opening end 3a side.

[0169] The inner bag 4 includes 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.

[0170] The second cylinder 4b includes a peripheral wall 4b1 and a lower wall 4b2 disposed below the peripheral wall 4b1 and configured to reduce the diameter of the peripheral wall 4b1 toward the first cylinder 4a. The peripheral wall 4b1 preferably has a portion extending parallel to the axial direction. The lower wall 4b2 is preferably disposed within the outer shell 3.

[0171] As shown in Figure 37, the inner bag 4 has a recess 4h in a 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 a portion facing the outer shell 3, and air can be introduced through the recess 4h into the intermediate space SP1 (shown in Figure 38) between the inner bag 4 and the outer shell 3. As shown in Figure 36, the recess 4h is preferably provided so as to extend to a position higher than the opening edge 3a of the outer shell 3. In this case, air flows more smoothly through the recess 4h.

[0172] As shown in Figure 37, the recess 4h is provided at the corner 4b3 between the bottom wall 4b2 and the peripheral wall 4b1. In this case, the recess 4h functions as a reinforcing rib, increasing the rigidity of the second tube 4b, making it easier to rotate the inner bag 4 relative to the outer shell 3 when pulling out the inner bag 4. The corner 4b3 is also located inside the outer shell 3. In this case, a gap is unlikely to form between the inner bag 4 and the outer shell 3, so there is significant technical significance in providing the recess 4h to make it easier for air to be introduced into the intermediate space SP1 between the inner bag 4 and the outer shell 3.

[0173] As shown in Figure 39, the lower surface 4b4 of the second tube 4b is preferably supported by abutting against the inner bag support surface 3a3. Supporting 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 edge 3a, or may be located lower than the opening edge 3a. In this embodiment, the inner bag support surface 3a3 is located lower than the opening edge 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.

[0174] A cam mechanism 31 is preferably provided between the inner bag 4 and the outer shell 3. The cam mechanism 31 functions to displace the inner bag 4 in a direction that allows it to come out of 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 configured, for example, by a ridge 4g provided on the outer peripheral surface of the inner bag 4 and a cam rail 3l provided on the inner peripheral 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 even easier to pull out.

[0175] Furthermore, before the inner bag 4 is pulled out of the container body 2, the ridge 4g is preferably positioned within the groove 3v provided on the outer shell 3. The outer shell 3 is provided with an engagement protrusion 3t at a position that abuts against the ridge 4g when the ridge 4g attempts to displace in the loosening direction. The ridge 4g abuts against the engagement protrusion 3t, preventing the ridge 4g from displacing, thereby preventing the inner bag 4 from accidentally slipping out. A protrusion 4k is provided downstream of the ridge 4g in the loosening direction. The undersides of the ridge 4g and the protrusion 4k are similarly inclined. By providing the protrusion 4k, even if the ridge 4g falls off the cam rail 3l when climbing over the engagement protrusion 3t, the cam mechanism 31 functions by the protrusion 4k moving along the cam rail 3l. The inner bag 4 is also provided with a movement suppression portion 4p. The movement suppression portion 4p abuts against the abutment surface 3w of the outer shell 3 when the inner bag 4 is rotated in the opposite direction to the loosening direction. This prevents the inner bag 4 from being accidentally rotated in the reverse direction. The movement suppressing portion 4p is provided on the protrusion 4k.

[0176] 35 and 36, 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.

[0177] As shown in Figures 38 and 39, the spout-mounted member 8 preferably includes a main body member 41, an opening / closing member 49, and an air flow restriction member 53. The main body member 41 is a member that is 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 includes a discharge port 8d for discharging the contents in the inner bag 4. The opening / closing member 49 is configured to be able to open and close the discharge port 8d. The opening / closing member 49 is preferably engageable with the main body member 41 by a screw or a snap fit. The opening / closing member 49 can be omitted if not required.

[0178] The main body member 41 includes an outer tube 41a, an inner tube 41b, an upper wall 41e, a discharge valve 44, and a nozzle member 50. The outer tube 41a is disposed outside the opening 5. Through holes 41k are provided in the circumferential surface of the outer tube 41a. In this embodiment, the number of through holes 41k is two, but the number may be one or three or more. Because the through holes 41k are provided in the circumferential surface of the outer tube 41a, communication between the through holes 41k and the intermediate space SP1 is easier than when the through holes 41k are provided in the upper wall 41e. Furthermore, if the through holes 41k were provided in the upper wall 41e, there is a risk that the through holes 41k would be blocked by the opening / closing member 49. However, in this embodiment, the through holes 41k are provided in the outer tube 41a, so this problem does not occur.

[0179] The air flow restriction member 53 is attached to the main body member 41 so as to restrict the flow of air through the through-hole 41k. The air flow restriction member 53 restricts the flow of air between the external space SP2 and the intermediate space SP1. Examples of the air flow restriction member 53 include an air-permeable membrane that allows a slight flow of air, and a valve body that restricts the air flow by changing the opening of the through-hole 41k through deformation or displacement.

[0180] The air flow restriction member 53 is preferably attached to the outer tube 41a. The air flow restriction member 53 is preferably disposed on the inner surface of the outer tube 41a. The air flow restriction member 53 preferably does not protrude from the outer surface of the outer tube 41a. In this case, the air flow restriction member 53 is less visible from the outside, resulting in an aesthetically pleasing appearance. The air flow restriction member 53 is preferably not inserted into the through-hole 41k. The air flow restriction member 53 is preferably a separate member independent of the main body member 41. In this case, the main body member 41 and the air flow restriction member 53 can be prepared separately, and then the air flow restriction member 53 can be attached to the main body member 41 by a joining method such as engagement or adhesive. The air flow restriction member 53 is preferably detachable from the main body member 41 even after being attached to the main body member 41. The air flow restriction member 53 is preferably composed of a single member. In this case, component costs can be reduced more easily than with a valve composed of multiple members, such as a ball valve in which a ball moves inside a cylinder.

[0181] 40 and 41, the air flow restriction member 53 is preferably an annular valve 53b. The angle at which the annular valve 53b extends in the circumferential direction in a cross section (i.e., the cross section of FIG. 40A) that is perpendicular to the central axis C and passes through the through-hole 41k (more specifically, the center of the through-hole 41k) 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 53b may be completely annular (i.e., the angle is 360 degrees) or may have a shape in which a portion of the annular ring is missing (i.e., the angle is less than 360 degrees). Specifically, this angle may be, for example, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, or 360 degrees, or may be in a range between any two of the values ​​exemplified here.

[0182] The annular valve 53b has the advantages of a simple structure and a low space occupancy rate within the outer cylinder 41a. The annular valve 53b is preferably cylindrical, either completely or partially missing. The annular valve 53b is preferably arranged concentrically with the outer cylinder 41a. The outer peripheral surface of the annular valve 53b faces the inner peripheral surface of the outer cylinder 41a. The outer peripheral surface of the annular valve 53b preferably has a shape similar to that of the inner peripheral surface of the outer cylinder 41a. When no compressive force is applied to the body 6 of the double container 1, the outer peripheral surface of the annular valve 53b may or may not abut the inner peripheral surface of the outer cylinder 41a.

[0183] An annular housing portion 41m is provided on the inner peripheral surface of the outer cylinder 41a in a region including the through-hole 41k. The annular housing portion 41m is configured to be able to house the annular valve 53b. By disposing the annular valve 53b in the annular housing portion 41m, the annular valve 53b can be positioned appropriately without providing any other joining means. The annular housing portion 41m is provided between the annular protrusion 41p and the engagement portion 8b.

[0184] The annular valve 53b preferably has flexibility that allows it 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.

[0185] The thickness of the annular valve 53b is not particularly limited, and may be, 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. Specific examples of the thickness include 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 mm, and may be in a range between any two of the values ​​exemplified here.

[0186] The width (i.e., length in the axial direction) of the annular valve 53b is, for example, 2 to 10 mm (4.8 mm in this embodiment), preferably 3 to 7 mm. Specifically, this width may be, for example, 2, 3, 4, 5, 6, 7, 8, 9, or 10 mm, or may be in a range between any two of the values ​​exemplified here.

[0187] The material of the annular valve 53b may be a soft resin such as low-density polyethylene or elastomer, or silicone rubber.

[0188] An engagement portion 8b is provided on the inner peripheral surface of the outer cylinder 41a. The engagement portion 8b is configured as an annular convex portion that protrudes radially inward from the outer cylinder 41a. A plurality of engagement protrusions 41j that protrude radially inward from the outer cylinder 41a are provided between the engagement portion 8b and the upper wall 41e. The plurality of engagement protrusions 41j are arranged spaced apart in the circumferential direction. The engagement portion 8b axially engages with the axial engagement portion 4ma, thereby engaging the main body member 41 axially with the protrusion 4c. The engagement protrusions 41j circumferentially engage with the circumferential engagement portion 4mb, thereby engaging the main body member 41 circumferentially with the protrusion 4c.

[0189] The inner cylinder 41b is disposed inside the outer cylinder 41a. The outer cylinder 41a and inner cylinder 41b are connected via an upper wall 41e. The discharge valve 44 is configured to allow the contents of the inner bag 4 to be discharged while preventing outside air from entering the inner bag 4. The nozzle member 50 is a member having a nozzle 8c and is attached to the upper wall 41e. The tip of the nozzle 8c forms the discharge port 8d. In this embodiment, the discharge valve 44 is disposed inside the inner cylinder 41b, but it may be disposed in another position, for example, inside the nozzle 8c.

[0190] The opening / closing member 49 includes an outer tube 49a, an inner tube 49b, and an upper wall 49d. The inner tube 49b is disposed inside the outer tube 49a. The outer tube 49a and the inner tube 49b are connected via the upper wall 49d. The upper wall 49d does not have a discharge port for discharging the contents of the inner bag 4.

[0191] When the opening / closing member 49 closes the discharge port 8d, the inner tube 49b is inserted into the nozzle 8c of the main body member 41 and is in close contact with the inner surface of the nozzle 8c. The bottom surface of the outer tube 49a abuts against the upper wall 41e of the main body member 41. From this state, by gripping the outer tube 49a and applying an upward force to the opening / closing member 49, the opening / closing member 49 can be separated from the main body member 41 to open the discharge port 8d.

[0192] 38 , the main body member 41 includes an inner bag contacting portion 41n where the main body member 41 is in close contact with the inner bag 4, and an outer shell contacting portion 41l where the main body member 41 is in close contact with the outer shell 3. A sealed space SP3 formed by the main body member 41 and the container body 2 is formed between the inner bag contacting portion 41n and the outer shell contacting portion 41l. In this embodiment, the inner bag contacting portion 41n is formed by inserting the inner tube 41b into the protruding portion 4c and contacting the inner surface of the protruding portion 4c (more specifically, the inner surface 4f1 of the tubular sealing portion 4f). In this embodiment, the outer shell contacting portion 41l is formed by contacting the inner circumferential surface of the outer tube 41a (more specifically, the tip portion 41a2 of the outer tube 41a) with the outer circumferential surface of the outer shell 3 (more specifically, the first flange portion 3f1).

[0193] 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 engagement 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 is connected to the intermediate space SP1 through the gap between the opening end 3a of the outer shell 3 and the protruding portion 4c of the inner bag 4. Therefore, there is no need to provide an opening in the outer shell 3 to allow air to circulate.

[0194] 39 , the mouth portion attachment member 8 can be attached to the mouth portion 5 with the first flange portion 3f1 or the second flange portion 3f2 supported. The mouth portion attachment member 8 is preferably of a plugging type. With the first flange portion 3f1 or the second flange portion 3f2 supported, the mouth portion attachment member 8 is placed over the protruding portion 4c. When a downward force is applied to the mouth portion attachment member 8 in this state, the engaging portion 8b overcomes the axial engaging portion 4ma and engages with the axial engaging portion 4ma, thereby attaching the mouth portion attachment member 8 to the mouth portion 5. At this time, the engaging protrusion 41j engages circumferentially with the circumferential engaging portion 4mb, thereby circumferentially engaging the main body member 41 with the protruding portion 4c.

[0195] <Operation of the Double Container 1> When the user presses the barrel 6 of the container body 2 to dispense the contents from the double container 1, the outer shell 3 is compressed. The air flow restriction member 53 prevents air from leaking from the intermediate space SP1 when the outer shell 3 is compressed, so that the pressure in the intermediate space SP1 increases as the outer shell 3 is compressed, 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 as the outer shell 3 is compressed, and the contents within the inner bag 4 are dispensed through the discharge valve 44. The discharge of the contents causes the inner bag 4 to contract. The discharge valve 44 is configured to prevent outside air from entering the inner bag 4, so outside air does not enter the inner bag 4, and the inner bag 4 remains contracted.

[0196] 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. Because the air flow restriction member 53 is configured to allow air to flow from the external space SP2 into the intermediate space SP1 when the compression of the outer shell 3 is released, outside air is quickly introduced into the intermediate space SP1 as the pressure in the intermediate space SP1 decreases, and as a result, the outer shell 3 quickly returns to its original shape.

[0197] 40A, when the air flow restricting member 53 is an annular valve 53b, the annular valve 53b is pressed against the inner surface of the outer tube 41a, closing the through-hole 41k and preventing air from leaking from the intermediate space SP1 during compression of the outer shell 3. When the outer shell 3 is released from compression, the annular valve 53b bends as the pressure in the intermediate space SP1 decreases, forming a gap between the annular valve 53b and the outer tube 41a, allowing air to flow in through the through-hole 41k, as shown in FIG.

[0198] 1-2. Manufacturing method of double container 1 The container body 2 can be manufactured by biaxially stretching blow molding the preform 15 shown in Figures 42 and 43. The double container 1 can also be manufactured by attaching the mouth attachment member 8 to the container body 2.

[0199] 2. Other Embodiments In the above embodiment, the spout attachment member 8 is attached to the inner bag 4 by engaging the spout attachment member 8 with the inner bag 4 in the axial direction, but the spout attachment member 8 may be attached to the outer shell 3 by engaging the spout attachment member 8 with the outer shell 3 in the axial direction. In the above embodiment, the spout attachment member 8 is attached to the container body 2 by a stoppering method, but it may also be attached to the container body 2 by a screw method.

[0200] 1: double container, 2: container body, 2a: molded body, 2c: gap, 3: outer shell, 3a: opening end, 3a1: base surface, 3a2: annular convex portion, 3a3: inner bag support surface, 3f1: first flange portion, 3f2: second flange portion, 3g4: outer peripheral surface, 3h: outside air introduction hole, 3h1: base portion, 3h2: tip portion, 3h3: flat portion, 3i: outer surface, 3j: recessed portion, 3j1: engaging protrusion, 3k: recessed portion, 3l: cam rail, 3m: engaging protrusion, 3n: intermediate region, 3o: enlarged diameter portion, 3p: inner tapered portion, 3q: outer tapered portion, 3r: recessed portion, 3s: engaging protrusion, 3t: engaging protrusion, 3v: recessed strip, 3w: abutting surface, 4: Inner bag, 4a: first cylinder, 4b: second cylinder, 4b1: peripheral wall, 4b2: lower wall, 4b3: corner, 4b4: lower surface, 4c: protrusion, 4c10: upper surface, 4c 11: Opening portion, 4c12: Male thread portion, 4c13: Inner peripheral surface, 4c2: Engagement convex portion, 4c3: Engagement portion, 4c5: Tip portion, 4c6: Engagement portion, 4c7 : Outer peripheral surface, 4c9: Reduced diameter part, 4d: Inner bag body, 4f: Seal cylinder part, 4f1: Inner surface, 4g: Convex strip, 4h: Recessed part, 4k: Projection, 4m: Engaging part, 4ma: Axial engaging part, 4mb: Circumferential engaging part, 4n: Recessed part, 4o: Cam convex part, 4p: Movement suppressing part, 5: Mouth part, 5a: Upper mouth part, 5b: Lower mouth part , 5b1: base, 5c: opening end, 5d: flange portion, 5d1: lower surface, 6: body portion, 6b: shoulder portion, 6c: body portion main body, 7: bottom portion, 8: mouth portion attachment member, 8a: cap, 8b: engagement portion, 8c: nozzle, 8d: discharge port, 8h: outside air introduction hole, 9: check valve, 9a: valve body, 9a1: first opening, 9a10: tip surface, 9a2: second opening, 9a3: space, 9a4: first contact portion, 9a5: second contact portion, 9a6: base portion, 9a7: tip portion, 9a8: flat portion, 9a9: opening, 9aa: first member, 9ab: second member, 9ab1: vent hole, 9b: moving body, 9c: tubular portion, 9d: flange portion, 9f : arm, 9f1: protrusion, 9f2: claw portion, 13: outer preform, 13a: mouth portion, 13b: body portion, 13c: bottom portion, 13d: flange, 13f: opening end, 13f1: first flange portion, 13f2: second flange portion, 13f3: lower surface, 13g: outside air introduction hole, 13h: annular convex portion, 13i: intermediate region, 13r: recess, 14: inner preform, 14a: mouth portion, 14b: body portion, 14c: bottom portion, 14d: protrusion portion, 14e: portion, 14f: extension portion, 14g: opening end, 14h: enlarged diameter portion, 14i: reduced diameter portion, 14j: inclined portion, 14o: cam convex portion, 15: preform, 15a: mouth portion,15b: body portion, 15c: bottom portion, 15f: opening end, 21: blow core, 21a: base portion, 21b: insertion portion, 21c: through hole, 21g: tip portion, 21h: reduced diameter portion, 21i: inclined portion, 21j: expanded diameter portion, 22: bottom support mold, 22a: annular convex portion, 22b: protrusion, 23: molding mold, 23a: cavity surface, 23b: flange accommodating portion, 23c: opposing surface, 23d: flange abutting surface , 25: stretching rod, 31: cam mechanism, 32: heater, 33: heat shielding portion, 35: heating device, 36: blow molding device, 41: main body member, 41A: cap body, 41a: outer tube, 41a1: opening end, 41a2: tip portion, 41b: inner tube, 41b1: inner circumferential surface, 41d: main body member sealing tube, 41d2: inner circumferential surface, 41d4: engaging protrusion, 41e: upper wall, 41g: top surface portion, 41h : insertion hole, 41i: communication hole, 41j: engagement protrusion, 41k: through hole, 41l: outer shell contact portion, 41m: annular storage portion, 41n: inner bag contact portion, 41p: annular protrusion, 42: overcap, 43: discharge member, 43a: discharge port, 43b: female thread portion, 44: discharge valve, 45: discharge member body, 45a: nozzle, 45b: engagement tube, 45c: top surface portion, 45d: discharge port, 46: overcap Bar cap, 47: dotted line, 48: sealing member, 49: opening / closing member, 49a: outer cylinder, 49b: inner cylinder, 49d: upper wall, 50: nozzle member, 51: contact surface, 52: contact surface, 53: regulating member, 53a: joint portion, 53b: annular valve, 54: rotation regulating mechanism, 55: contact surface, 56: contact surface, C: central axis, SP1: intermediate space, SP2: external space, SP3: sealed space, T: wall thickness,

Claims

1. A double container comprising a container body, wherein the container body is a biaxially stretched blow molded body, the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the container body is provided with an outside air inlet hole penetrating the outer shell and an air flow regulating member that regulates the flow of air through the outside air inlet hole, and at least one of the components constituting the air flow regulating member is welded or adhered to the outer shell.

2. A double container as described in claim 1, wherein the air flow regulating member comprises a valve body and a moving body, the moving body being configured to be able to move within the space within the valve body, the valve body comprising a tubular portion having the space and a flange portion protruding radially from the tubular portion, and the flange portion being welded or bonded to the outer shell.

3. A double container according to claim 2, wherein the cylindrical portion is inserted into the outside air introduction hole.

4. A double container as described in claim 1, wherein the air flow regulating member comprises a valve body and a moving body, the moving body being configured to be movable within the space within the valve body, the valve body being configured by combining a first member and a second member, the first member having an opening through which the moving body can pass without deforming the first member, the second member having an air hole through which the moving body cannot pass, and the second member being welded or glued to the first member so that the air hole communicates with the opening, and the first member or the second member being configured by the outer shell.

5. A method for manufacturing a double-layered container, comprising a biaxially stretched blow molding step and an arrangement step, wherein in the biaxially stretched blow molding step, a preform is biaxially stretched blow molded, the preform is configured by placing an outer preform over an inner preform, the outer preform has an outside air introduction hole at its bottom that passes through the outer preform, the biaxially stretched blow molding is performed with the bottom supported by a bottom support mold, and in the arrangement step, after the biaxially stretched blow molding, an air flow regulating member is arranged to regulate the flow of air through the outside air introduction hole.

6. A method according to claim 5, wherein the container body formed by the method including the biaxially stretched blow molding step comprises an inner bag and an outer shell arranged to cover the inner bag, and the air flow restriction member is arranged by welding or adhering at least one of the members constituting the air flow restriction member to the outer shell.

7. The method according to claim 5, wherein the outer preform has an annular protrusion surrounding the external air introduction hole, and the bottom support mold is configured to suppress extension of the annular protrusion.

8. A method according to any one of claims 5 to 7, wherein the air flow restriction member is a check valve, the check valve comprises a valve body and a movable body that is movable within the space within the valve body, and the outside air introduction hole is configured to be able to accommodate at least a portion of the valve body.

9. A double container comprising a container body, wherein the container body is a biaxially stretched blow molded body, the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the outer peripheral surface of the outer shell is provided with first and second flange portions in that order from the open end side of the outer shell, and the outer shell is provided with an outside air inlet hole in the intermediate region between the first and second flange portions.

10. A double container according to claim 9, comprising an air flow restriction member that restricts the flow of air through the outside air inlet hole, the air flow restriction member being positioned in the intermediate region.

11. A double container according to claim 10, wherein the air flow regulating member is a check valve comprising a valve body and a moving body, the moving body being configured to be movable within the space within the valve body, and the valve body being positioned in the intermediate region.

12. A double container according to claim 11, wherein the valve body comprises a cylindrical portion having the space and an arm extending from the cylindrical portion, the arm having a protrusion, and the protrusion being inserted into a recess provided in the intermediate region.

13. A double container as described in claim 10, wherein the air flow regulating member is a check valve having a valve body and a moving body, the moving body is configured to be movable within the space within the valve body, and the valve body is configured by the outer shell and the inner bag.

14. A double container comprising a container body and an air flow restriction member, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the outer shell having an outside air introduction hole, the air flow restriction member comprising a valve body and a moving body, and being a check valve configured to restrict the flow of air through the outside air introduction hole, the moving body being configured to be able to move within the space within the valve body, the valve body comprising a tubular portion having the space and an arm extending from the tubular portion, the arm having a protrusion, and the protrusion being inserted into a recess provided in the outer shell.

15. A double container comprising a container body and an air flow regulating member, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the outer shell having an outside air introduction hole, the air flow regulating member comprising a valve body and a moving body and being a check valve configured to regulate the flow of air through the outside air introduction hole, the moving body being configured to be movable within the space within the valve body, and the valve body being composed of the outer shell and the inner bag.

16. A method for manufacturing a double-layered container, comprising a biaxially stretched blow molding process, wherein in the biaxially stretched blow molding process, a preform is biaxially stretched blow molded, the preform is constructed by placing an outer preform over an inner preform, the outer preform is provided with first and second flange portions in that order from the open end side of the outer preform, and the outer preform is provided with an outside air introduction hole in the intermediate region between the first and second flange portions.

17. A double container comprising a container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, 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 of coming out of the container body by rotating the inner bag relative to the outer shell, and the rotation restriction mechanism 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.

18. A double container comprising a container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the container body is provided with a cam mechanism, and the cam mechanism is configured to displace the inner bag in a direction that causes it to escape from the container body by rotating the inner bag relative to the outer shell, and a gap is 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.

19. A double container as claimed in claim 17 or claim 18, 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 so that the cam protrusion moves along the cam rail as the inner bag rotates relative to the outer shell, thereby displacing the inner bag.

20. A double container as described in claim 19, 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 abutting contact 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 surface is released.

21. A double container according to claim 19, which relies on claim 17, wherein the rotation restriction mechanism includes at least one engaging protrusion provided along the cam rail.

22. A double container as described in claim 17, 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 towards the base.

23. A double container as described in claim 17, comprising a mouth attachment member attached to the mouth of the container body, the mouth attachment member having an outside air introduction hole communicating with the intermediate space between the outer shell and the inner bag.

24. A double container according to claim 23, wherein the opening attachment member is provided with an air flow restriction member that restricts the flow of air through the outside air introduction hole.

25. A double container according to claim 23, wherein the opening attachment member is in close contact with both the inner bag and the outer shell.

26. A method for manufacturing a double-layered container according to claim 17, wherein the container body is formed by biaxially stretched blow molding.

27. 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 mouth attachment member is attached to the mouth of the container body, the mouth attachment member comprises a body member attached to the container body and an air flow regulating member, the body member comprises an outer tube arranged on the outside of the mouth, the outer tube has a through hole on its circumferential surface, the air flow regulating member is attached to the body member so as to regulate the flow of air through the through hole, and the air flow regulating member regulates the flow of air between the intermediate space between the outer shell and the inner bag and the external space of the double container.

28. A double container according to claim 27, wherein the air flow restricting member is disposed on the inner surface side of the outer cylinder.

29. A double container according to claim 27, wherein the air flow regulating member is a valve body that changes the opening of the through hole by deformation or displacement.

30. A double container according to claim 29, wherein the valve element is an annular valve, and the outer peripheral surface of the annular valve and the inner peripheral surface of the outer cylinder are arranged to face each other.

31. A double container according to any one of claims 27 to 30, wherein the outer tube is in close contact with the outer shell at an outer shell contact portion, the inner bag has a protruding portion that protrudes from the outer shell, the outer tube has an engaging portion that engages with an axial engaging portion provided on the protruding portion, and the through hole is positioned between the engaging portion and the outer shell contact portion.

32. A method for manufacturing a double container according to claim 27, wherein the container body is formed by biaxially stretch blow molding a preform.

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