Double container

Abstract

To provide a double container capable of reducing a protrusion amount of an inner bag from an opening end of an outer shell.SOLUTION: A double container includes: a container body; and a mouth part mounting member mounted on a mouth part of the container body. The container body includes: an inner bag; and an outer shell arranged so as to cover the inner bag. The inner bag includes a protrusion part protruding from an opening end of the outer shell. At the protrusion part, an engagement part is provided capable of being engaged with the mouth part mounting member, and the engagement part comes into contact with the outer shell.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, a double container having a container body having an outer shell and an inner bag is known. For example, Patent Document 1 discloses a method of manufacturing a container body having an inner bag and an outer shell covering the inner bag by biaxially stretching and blow molding a preform formed by covering an inner preform with an outer preform. In addition, in the container body of Patent Document 1, the inner bag has a protruding portion protruding from the open end of the outer shell, and the protruding portion is provided with an abutting flange that abuts against the open end of the outer shell. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-26868 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the mouth attachment member is engaged with an engagement protrusion provided on the inner bag, and the inner bag is pulled out by pulling the mouth attachment member. Also, a seal structure is adopted in which the outer peripheral surface of the inner tube provided on the mouth attachment member is tightly attached to the inner peripheral surface of the inner bag. In Patent Document 1, the engagement protrusion of the inner bag is provided at the open end of the inner bag, and the above seal structure is formed at the portion where the engagement protrusion is provided.

[0005] When the inner preform is formed by injection molding, the shape of the inner surface of the inner preform does not reflect the shape of the outer surface, making it possible to adopt the above-mentioned sealing structure. However, when the inner preform is formed by direct blow molding, the shape of the inner surface of the inner preform reflects the shape of the outer surface, so that a recess that reflects the shape of the outer surface of the engaging convex portion is formed on the inner surface of the engaging convex portion, making it difficult to adopt the above-mentioned sealing structure.

[0006] When the inner preform is formed by direct blow molding, it is possible to provide a portion where the above-mentioned seal structure can be formed on the opening end side closer to the engaging convex portion; however, in that case, problems are likely to arise such as the protruding portion protruding too much, reducing the freedom of selection of the mouth attachment member.

[0007] The present invention has been made in consideration of the above circumstances, and provides a double container that can reduce the amount of protrusion of the inner bag from the open end of the outer shell. [Means for solving the problem]

[0008] According to the present invention, the following inventions are provided. [1] A double container comprising a container body and a mouth attachment member attached to the mouth of the container body, wherein the container body comprises an inner bag and an outer shell arranged to cover the inner bag, the inner bag has a protrusion protruding from the opening end of the outer shell, the protrusion has an engagement portion capable of engaging with the mouth attachment member, and the engagement portion abuts against the outer shell. [2] The double container according to [1], wherein a recess is provided on the inner circumferential surface of the engaging portion. [3] A double container as described in [1] or [2], wherein the inner bag has a sealing tube portion located closer to the opening end of the inner bag than the engagement portion, the engagement portion has an inclined wall provided so as to reduce the diameter of the engagement portion toward the sealing tube portion, and the inner surface of the sealing tube portion is in close contact with the outer peripheral surface of the inner tube provided on the mouth attachment member. [4] The double container according to any one of [1] to [3], wherein the outer shell has a flange portion at an open end of the outer shell, and the flange portion abuts against the engagement portion. [5] A method for manufacturing a double container described in any one of [1] to [4], comprising a step of manufacturing the container body by biaxially stretching blow molding a preform, the preform comprising an inner preform which becomes the inner bag and an outer preform which becomes the outer shell, the inner preform being formed by direct blow molding. Effect of the Invention

[0009] In conventional double containers such as that in Patent Document 1, an abutment flange is provided on the underside of the engagement portion, and the abutment flange is abutted against the outer shell to prevent the inner bag from penetrating into the outer shell. However, in the double container of the present invention, the engagement portion of the inner bag is abutted against the outer shell to prevent the inner bag from penetrating into the outer shell, so there is no need to provide a configuration such as the abutment flange in Patent Document 1, and the amount of protrusion of the inner bag from the opening end of the outer shell can be reduced. [Brief description of the drawings]

[0010] [Figure 1] 1 is a perspective view of a double container 1 according to a first embodiment of the present invention. The dashed and dotted lines in the figure represent the boundary lines at which the curvature of the faces that make up the surface shape changes. The same is true for the other figures. [Diagram 2] FIG. 2 is an exploded perspective view of the double container 1 of FIG. [Diagram 3] 2 is a longitudinal cross-sectional view of the double container 1 of FIG. 1 with the overcap 42 closed. [Figure 4] FIG. 4 is an exploded view of FIG. 3 with the overcap 42 slightly open. [Diagram 5] 5 is a divided view of the container body 2 in FIG. 4. FIG. [Figure 6] FIG. 3 is an exploded perspective view of the vicinity of the mouth portion 5 in FIG. 2. [Figure 7]Fig. 7A is a perspective view of the cap body 41 of the mouth-mounted member 8 in Fig. 2, seen from a different angle. Fig. 7B is a cross-sectional perspective view of the cap body 41 in Fig. 7A cut in half. [Figure 8] FIG. 2 is a perspective view showing a state in which the inner preform 14 and the outer preform 13 are separated. [Figure 9] 1 is a perspective view of a preform 15 formed by covering an inner preform 14 with an outer preform 13. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments of the present invention will be described. The various features shown in the following embodiments can be combined with each other. Each feature can be an independent invention. In the following embodiments, elements that are not specified in the claims are optional elements and can be omitted.

[0012] 1. First embodiment The double container according to the first embodiment of the present invention will be described with reference to Figs. 1 to 9. In the following description, terms related to directions such as "upper" and "lower" refer to directions when the bottom 7 is in contact with the ground. In addition, in the following description, the "axial direction" refers to the direction in which the central axis C (shown in Fig. 2) of the mouth 5 extends, in other words, the direction in which the inner bag 4 is pulled out from the container body 2. The "circumferential direction" refers to the direction of rotation about the central axis C of the mouth 5, in other words, the direction in which the inner bag 4 is rotated relative to the outer shell 3 at the mouth 5. "Clockwise" and "counterclockwise" refer to directions as viewed from the top of the double container 1, unless otherwise specified.

[0013] 1-1. Structure of double container 1 As shown in Fig. 1, the double container 1 of the first embodiment of the present invention comprises a container body 2 and a mouth attachment member 8. Each component will be described in detail below.

[0014] <Basic configuration of container body 2> As shown in Figures 2 and 3, the container body 2 has a mouth 5, a body 6, and a bottom 7. The mouth 5 is a tubular (preferably cylindrical) portion having an open end 5c. The open end 5c is the open end of the container body 2 and also the open end of the inner bag 4. The mouth 5 has an engagement portion 4m to which a mouth attachment member 8 can be attached.

[0015] The body 6 is disposed adjacent to the mouth 5 on the side farther from the open end 5c than the mouth 5. The body 6 has a larger outer diameter (in this specification, "outer diameter" means a circular equivalent diameter when the cross section is not circular) than the mouth 5. The body 6 is cylindrical, and the bottom 7 is provided at the lower end of the body 6 and closes the lower end of the body 6. The body 6 has a shoulder 6b whose outer diameter increases with increasing distance from the mouth 5. The body 6 also has a body main body 6c on the bottom 7 side of the shoulder 6b. The body main body 6c has a shape in which the outer diameter is approximately constant toward the bottom 7, or a shape in which the diameter decreases toward the bottom 7, for example.

[0016] 3 to 6, the container body 2 includes an inner bag 4 and an outer shell 3 arranged to cover the inner bag 4. The inner bag 4 has an inner bag body 4d other than the protruding portion 4c housed within the outer shell 3. In the following description, the portions of the inner bag 4 that correspond to the mouth 5, body 6, and bottom 7 of the container body 2 will be referred to as the mouth 5, body 6, and bottom 7 of the inner bag 4, respectively. The same applies to the outer shell 3.

[0017] <Detailed structure of outer shell 3 and inner bag 4> 4, the inner bag 4 has a protruding portion 4c protruding from the open end 3a of the outer shell 3. The protruding portion 4c is provided with an engaging portion 4m that can be engaged with the mouth-mounted member 8.

[0018] 4, an engagement portion 8b engageable with the engagement portion 4m is provided on the inner circumferential surface of the outer tube 41a of the mouth-mounted member 8, and the mouth-mounted member 8 is mounted on the mouth 5 by engaging the engagement portion 8b with the engagement portion 4m. A recess 4c13 is provided on the inner circumferential surface of the engagement portion 4m.

[0019] As shown in Fig. 6, the engaging portion 4m preferably includes an annular protrusion 4c5 and an engaging protrusion 4c2. The annular protrusion 4c5 engages with the engaging portion 8b of the mouth mounting member 8 in the axial direction. The engaging protrusion 4c2 engages with the mouth mounting member 8 in the circumferential direction. The engagement between the engaging protrusion 4c2 and the mouth mounting member 8 may be a concave-convex engagement or a frictional engagement. The engaging protrusion 4c2 may be omitted, in which case it is preferable that the annular protrusion 4c5 and the mouth mounting member 8 frictionally engage in the circumferential direction.

[0020] The engaging protrusions 4c2 are preferably provided at a plurality of locations (eight locations in this embodiment) spaced apart in the circumferential direction. The engaging protrusions 4c2 are disposed on the annular protrusion 4c5 and are provided so as to protrude radially outward from the annular protrusion 4c5. The annular protrusion 4c5 and the engaging protrusions 4c2 have tapered surfaces 4c8 on their upper surfaces. This makes it easier for the engaging portion 8b provided on the mouth attachment member 8 to climb over the annular protrusion 4c5 and the engaging protrusions 4c2 when the mouth attachment member 8 is attached.

[0021] The engaging portion 4m (more specifically, the lower surface 4m3 of the engaging portion 4m) abuts against the outer shell 3 (more specifically, the opening end 3a of the outer shell 3), thereby preventing the inner bag 4 from entering into the outer shell 3. In addition, according to this configuration, since there is no need to provide a configuration such as the abutting flange of Patent Document 1 on the lower side of the engaging portion 4m, the amount of protrusion of the inner bag 4 from the opening end 3a of the outer shell 3 can be reduced. If the amount of protrusion of the inner bag 4 is reduced, there is an advantage that the degree of freedom in selecting the mouth attachment member 8 is easily increased. For example, the F-port standard, which is widely adopted as the standard for the mouth attachment member, specifies that the axial length between the opening end 5c of the container body 2 and the lower surface of the support ring that supports the mouth 5 when the mouth attachment member 8 is attached is 10.2 mm. The greater the amount of protrusion of the inner bag 4, the more difficult it is to comply with this standard. However, according to the present invention, since it is possible to reduce the amount of protrusion of the inner bag 4, it becomes possible to adopt the mouth attachment member 8 that complies with the F-port standard after making the shape of the mouth 5 comply with the F-port standard. Various types of mouth attachment members 8 that comply with the F mouth standard are commercially available and are highly available.

[0022] The inner bag 4 has a cylindrical seal portion 4f at a position closer to the open end 5c of the inner bag 4 than the engaging portion 4m. The engaging portion 4m has an inclined wall 4n provided so as to reduce the diameter of the engaging portion 4m toward the cylindrical seal portion 4f. The inner surface of the cylindrical seal portion 4f is in close contact with the outer peripheral surface 41b1 of the inner tube 41b provided on the mouth attachment member 8. The inner bag 4 is preferably formed by biaxially stretching blow molding the inner preform 14, which is a direct blow molded body. When the inner bag 4 is formed by this method, a recess 4c13 is formed on the inner peripheral surface of the engaging portion 4m. If the recess 4c13 is present on the inner peripheral surface of the engaging portion 4m, the rigidity of the engaging portion 4m is lower than when the recess 4c13 is not present. Therefore, when the mouth attachment member 8 is engaged with the engaging portion 4m and the mouth attachment member 8 is pulled in the axial direction to pull out the inner bag 4, the engaging portion 4m may be deformed. In this embodiment, in order to suppress deformation of the engagement portion 4m, the force applied to the engagement portion 4m by the mouth mounting member 8 is easily transmitted to the cylindrical seal portion 4f through the inclined wall 4n, and the outer peripheral surface of the inner tube 41b is brought into contact with the inner surface of the cylindrical seal portion 4f to suppress deformation of the cylindrical seal portion 4f. As shown in Fig. 5, the inclined wall 4n is preferably provided so as to connect the lower wall 4p of the engagement portion 4m and the cylindrical seal portion 4f.

[0023] The inner bag 4 has an expanded diameter portion 4o located closer to the open end 5c than the cylindrical seal portion 4f. This makes it easier to insert the inner tube 41b into the inner bag 4.

[0024] 6, a ridge 4g is provided on the outer circumferential surface of the inner bag 4 (more specifically, the inner bag main body 4d). The lower surface of the ridge 4g is inclined so as to approach the open end 5c in the counterclockwise direction.

[0025] A plurality of ridges 4g are provided on the outer peripheral surface of the inner bag 4, and the start and end points of the plurality of ridges 4g are offset from each other in the circumferential direction. In this embodiment, two ridges 4g are arranged offset from each other by 180 degrees in the circumferential direction. The angle at which each ridge 4g extends is preferably 180 degrees or less, and more preferably 90 degrees or less. This angle is, for example, 15 to 180 degrees, and preferably 30 to 90 degrees (about 45 degrees in this embodiment). Specifically, this angle may be, for example, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, or 180 degrees, or may be in a range between any two of the values ​​exemplified here.

[0026] A cam rail 3l is provided on the inner peripheral surface of the outer shell 3. A recessed strip 3m that can engage with the protruding strip 4g is provided in a portion of the cam rail 3l. The recessed strip 3m is preferably provided at the end of the cam rail 3l. The upper surface of the cam rail 3l is inclined so as to approach the opening end 3a as it advances in the counterclockwise direction. The protruding strip 4g and the recessed strip 3m are configured to be engageable by rotating the inner bag 4 clockwise relative to the outer shell 3, and to be disengaged by rotating the inner bag 4 counterclockwise relative to the outer shell 3. The recessed strip 3m is configured as a non-through hole. In this case, cracks are less likely to occur in the outer shell 3 compared to when the recessed strip 3m is configured as a through hole. A wide portion 3a1 in which the width of the opening end 3a is wider is provided at a portion directly above the recessed strip 3m. This makes it easier for the engagement portion 4m to be supported more stably at the opening end 3a.

[0027] A plurality of cam rails 3l are provided on the inner peripheral surface of the outer shell 3, and the start points and end points of the plurality of cam rails 3l are offset from each other in the circumferential direction. In this embodiment, two cam rails 3l are disposed offset by 180 degrees in the circumferential direction. The angle at which each cam rail 3l extends is preferably 360 degrees or less, and more preferably 270 degrees or less. This angle is, for example, 90 to 360 degrees, and preferably 120 to 240 degrees (180 degrees in this embodiment). 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.

[0028] The recessed strip 3m is preferably provided on each cam rail 3l. The angle at which the recessed strip 3m extends is the same as the angle at which the protruding strip 4g extends.

[0029] The container body 2 is preferably provided with a rotation restricting structure that restricts relative rotation between the inner bag 4 and the outer shell 3. Examples of the rotation restricting structure include a structure that increases the frictional force between the inner bag 4 and the outer shell 3, and a structure that engages the inner bag 4 and the outer shell 3 in a circumferential direction.

[0030] Before the inner bag 4 is pulled out from the container body 2, the lower surface of the ridge 4g abuts against the upper surface of the cam rail 3l within the groove 3m. The ridge 4g and the cam rail 3l form a cam mechanism 31. When the inner bag 4 is rotated counterclockwise relative to the outer shell 3, the cam mechanism 31 causes the inner bag 4 to be displaced in a direction that allows it to come out of the container body 2. At this time, the inner bag 4 is twisted and reduced in diameter. The cam mechanism 31 has an inclined structure in the same direction as a positive screw.

[0031] 5 and 6, 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 side of the outer shell 3. The cam mechanism 31 is preferably disposed so that the lower end of the cam mechanism 31 is closer to the opening end 3a than the lower surface 3f3 of the second flange portion 3f2. In this case, there is an advantage that the shape of the cam mechanism 31 is less likely to collapse during molding.

[0032] The first flange portion 3f1 is provided at the open end 3a of the outer shell 3. In other words, the first flange portion 3f1 constitutes a part of the open end 3a. The first flange portion 3f1 abuts against the engagement portion 4m. When the mouth attachment member 8 is engaged with the engagement portion 4m, a strong downward force is applied to the engagement portion 4m, which tends to deform the engagement portion 4m. However, by supporting the engagement portion 4m with the first flange portion 3f1, the deformation of the engagement portion 4m is suppressed. If the inner peripheral surface of the engagement portion 4m has a recess 4c13, the engagement portion 4m tends to deform, so the technical significance of suppressing the deformation of the engagement portion 4m by providing the first flange portion 3f1 is remarkable.

[0033] The second flange portion 3f2 can function as a support ring that supports the mouth portion 5 when the mouth mounting member 8 is attached to the mouth portion 5. The F standard specifies that the axial length between the opening end 5c of the container body 2 and the lower surface of the support ring that supports the mouth portion 5 when the mouth mounting member 8 is attached is 10.2 mm. In order to enable the mouth mounting member 8 to be attached to the mouth portion 5 using a device that complies with such a standard, the axial length L8 between the opening end 5c and the lower surface 3f3 of the second flange portion 3f2 is preferably 9.2 to 11.2 mm, and more preferably 9.7 to 10.7 mm. Specifically, the length L8 may be, for example, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11.0, 11.1, or 11.2 mm, or may be in a range between any two of the numerical values ​​exemplified here.

[0034] <Configuration of Mouth-mounted Member 8> The mouth attachment member 8 is a member that is attached to the mouth 5 of the container body 2. In this embodiment, the mouth attachment member 8 is a cap 8a, but may be another member such as a pump. As shown in FIG. 4, the mouth attachment member 8 has an engagement portion 8b that can engage with the engagement portion 4m. The engagement portion 8b is preferably an annular protrusion 8b3. The mouth attachment member 8 preferably has a discharge port 8d for discharging the contents in the inner bag 4. In addition, the mouth attachment member 8 preferably has a nozzle 8c.

[0035] The cap 8a preferably includes a cap body 41 and an overcap 42. The cap body 41 is configured to be able to engage with the protruding portion 4c, and includes an outlet 8d. The overcap 42 is configured to be able to open and close the outlet 8d. FIG. 3 shows a closed state in which the outlet 8d is closed, and FIG. 4 shows an open state in which the outlet 8d is open. In this embodiment, the cap body 41 and the overcap 42 are connected by a hinge 43, but they do not have to be connected. The overcap 42 is preferably able to engage with the cap body 41 by a screw or a snap fit.

[0036] The cap body 41 includes an outer cylinder 41a, an inner cylinder 41b, a nozzle 8c, and an upper wall 41d. The inner cylinder 41b is disposed inside the outer cylinder 41a. The outer cylinder 41a and the inner cylinder 41b are connected via the upper wall 41d. The nozzle 8c is disposed above the upper wall 41d. A flow hole 41i is provided in the upper wall 41d, and the flow passage of the inner cylinder 41b and the nozzle 8c are connected through the flow hole 41i. The tip of the nozzle 8c becomes the discharge port 8d. The inner cylinder 41b is inserted into the protruding portion 4c and is in close contact with the inner surface 4f1 of the sealing cylinder portion 4f. Therefore, the inner cylinder 41b and the sealing cylinder portion 4f are frictionally engaged in the circumferential direction. An engagement portion 8b is provided on the inner peripheral surface of the outer cylinder 41a.

[0037] The overcap 42 includes an outer tube 42a, an inner tube 42b, and an upper wall 42d. The inner tube 42b is disposed inside the outer tube 42a. The outer tube 42a and the inner tube 42b are connected via the upper wall 42d. The upper wall 42d is not provided with a discharge port for discharging the contents in the inner bag 4.

[0038] With the discharge port 8d closed by the overcap 42, the inner tube 42b is inserted into the nozzle 8c of the cap body 41 and is in close contact with the inner surface of the nozzle 8c. In addition, the bottom surface of the outer tube 42a abuts against the upper wall 41d of the cap body 41. From this state, by gripping the outer tube 42a and applying an upward force to the overcap 42, the overcap 42 can be separated from the cap body 41 to open the discharge port 8d.

[0039] <Attachment of mouth attachment member 8> 3 and 4, the mouth attachment member 8 can be attached to the mouth 5 with the second flange portion 3f2 supported. The mouth attachment member 8 is preferably of a plug type, and when the mouth attachment member 8 is placed over the protruding portion 4c with the second flange portion 3f2 supported and 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 engage with each other in the circumferential and axial directions, so that the mouth attachment member 8 can be attached to the mouth 5.

[0040] <Removing inner bag 4> The mouth attachment member 8 is engaged with the mouth 5 of the inner bag 4 in the circumferential and axial directions, and is configured so that the inner bag 4 rotates relative to the outer shell 3 as the mouth attachment member 8 rotates. The inner bag 4 is configured to move in a direction coming out of the container body 2 as the inner bag 4 rotates due to the action of a cam mechanism 31 provided between the inner bag 4 and the outer shell 3.

[0041] According to this configuration, by rotating the mouth attachment member 8, the inner bag 4 can be moved in a direction that allows it to be removed from the container body 2 while being twisted, and then by pulling the mouth attachment member 8, the inner bag 4 can be pulled out of the container body 2. Note that the inner bag 4 may be separated from the container body 2 by pulling it in the axial direction without twisting it. In this case, the mouth attachment member 8 may not be engaged with the mouth 5 of the inner bag 4 in the circumferential direction, but may be engaged only in the axial direction.

[0042] 1-2. Manufacturing method of double container 1 The container body 2 can be manufactured by biaxially stretching and blow molding a preform 15 shown in Fig. 9. In addition, the double container 1 can be manufactured by attaching the mouth attachment member 8 to the container body 2.

[0043] <Configuration of inner preform 14, outer preform 13, and preform 15> As shown in FIG. 8, the preform 15 includes an inner preform 14 which becomes the inner bag 4 and an outer preform 13 which becomes the outer shell 3 .

[0044] As shown in Fig. 8, the inner preform 14 is a cylindrical shape with a bottom, and includes a mouth portion 14a, a body portion 14b, and a bottom portion 14c. The bottom portion 14c is provided so as to close the lower end of the body portion 14b. The outer preform 13 is a cylindrical shape with a bottom, and includes a mouth portion 13a, a body portion 13b, and a bottom portion 13c. The bottom portion 13c is provided so as to close the lower end of the body portion 13b.

[0045] 9, 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.

[0046] The mouth portions 13a and 14a become the mouth portion 15a of the preform 15, the body portions 13b and 14b become the body portion 15b of the preform 15, and the bottom portions 13c and 14c become the bottom portion 15c of the preform 15. The body portion 15b and the bottom portion 15c are mainly stretched in the biaxial stretch blow molding. The mouth portion 15a is hardly deformed during molding and becomes the mouth portion 5 of the container body 2. The above-mentioned contents regarding the configuration included in the mouth portion 5 can also be applied to the configuration included in the mouth portion 15a as long as it is not contrary to the spirit thereof.

[0047] <Materials and manufacturing methods of inner preform 14, outer preform 13, and preform 15> The inner preform 14 and the outer preform 13 can be formed by direct blow molding or injection molding using a thermoplastic resin such as polyester (eg, PET) or polyolefin (eg, polypropylene, polyethylene).

[0048] The outer preform 13 is preferably formed by injection molding. The inner preform 14 is preferably formed by direct blow molding using a molten cylindrical parison. When the inner preform 14 is formed by direct blow molding, a structure in which a recess 4c13 is formed on the inner peripheral surface of the engagement portion 4m can be obtained. The inner preform 14 is preferably of a multi-layer structure.

[0049] 2. Other embodiments The direction in which each member is rotated relative to the above embodiment may be reversed. In the above embodiment, the inner bag 4 is displaced in a direction to come out of the container body 2 by rotating the clockwise thread in the loosening direction, but the inner bag 4 may be displaced in a direction to come out of the container body 2 by rotating the counterclockwise thread in the loosening direction. [Explanation of symbols]

[0050] 1:Double container 2: Container body 3: Outer shell 3a: Open end 3a1: Wide section 3f1: First flange section 3f2: Second flange part 3f3:Bottom surface 3l: Cam rail 3m: Concave 4: Inner bag 4c:Protrusion 4c2: Engagement convex part 4c5: Circular convex part 4c8: Tapered surface 4c13: Recess 4d: Inner bag body 4f: Seal cylinder 4f1:Inner surface 4g: Convex stripe 4m: Engagement part 4m3: bottom surface 4n : Inclined wall 4o: Enlarged diameter section 4p: Lower wall 5: Mouth 5c: Open end 6: Torso 6b:Shoulder 6c: Body 7: Bottom 8: Mouth attachment member 8a: Cap 8b: Engagement part 8b3: Circular convex part 8c: Nozzle 8d:Discharge port 13: Outer preform 13a: Mouth 13b: Torso 13c: Bottom 14: Inner preform 14a: Mouth 14b: Torso 14c: Bottom 15: Preform 15a: Mouth 15b: Torso 15c: bottom 31: Cam mechanism 41: Cap body 41a: Outer cylinder 41b: Inner cylinder 41b1: Outer surface 41d: Upper wall 41i :Flow hole 42: Overcap 42a: Outer cylinder 42b: Inner cylinder 42d: Upper wall 43: Hinge C: Central axis

Claims

1. A double container comprising a container body and a mouth attachment member attached to a mouth of the container body, The container body includes an inner bag and an outer shell arranged to cover the inner bag. The inner bag has a protrusion protruding from an open end of the outer shell, The protrusion is provided with an engagement portion that can be engaged with the mouth attachment member, The double container, wherein the engagement portion abuts against the outer shell.

2. The double container according to claim 1, The double container has a recess on the inner circumferential surface of the engagement portion.

3. The double container according to claim 1, the inner bag includes a cylindrical seal portion located closer to an open end of the inner bag than the engagement portion; The engagement portion includes an inclined wall provided to reduce a diameter of the engagement portion toward the tubular seal portion, The inner surface of the cylindrical seal portion is in close contact with the outer peripheral surface of the inner tube provided on the mouth attachment member.

4. The double container according to claim 1, The outer shell includes a flange portion at an open end of the outer shell, The flange portion abuts against the engagement portion.

5. A method for manufacturing a double container according to any one of claims 1 to 4, A step of producing the container body by biaxially stretching and blow molding a preform, The preform includes an inner preform that becomes the inner bag and an outer preform that becomes the outer shell, The method of claim 1, wherein the inner preform is formed by direct blow molding.

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