Cap structure and packaging container

Abstract

To provide a cap structure having a function of unsealing an inner plug by rotation of a cap and capable of being stably attached to a container body by capping, and to provide a packaging container using the same.SOLUTION: A cap structure to be attached to a mouth of a container body, comprises: an inner plug having a fitting part to be fitted to an open end of the mouth, a partition wall for sealing the inside of the fitting part, an annular fragile part disposed in the partition wall, and a protrusion connected to a portion surrounded by the fragile part in the partition wall; and a cap having a top plate, a cylindrical peripheral wall, an engagement part which is disposed on the inner surface side of the top plate and is engaged with the protrusion, and a plurality of columnar ribs having one end connected to the inner surface side of the top plate. The fragile part is broken by the drop of the protrusion accompanying the rotation of the cap in the closing direction, and the columnar ribs are bent.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cap structure for sealing the mouth of a container body and a packaging container using the same. [Background Art]

[0002] Various packaging containers have been proposed that include an inner plug and a cap for sealing a container body, and allow the inner plug to be opened by rotation of the cap. For example, Patent Document 1 describes a packaging container in which a planned opening portion of an inner plug is screwed together with an overcap, and the screwing engagement between the planned opening portion and the overcap is advanced by rotational movement of the overcap in the opening direction, so that the planned opening portion of the inner plug can be cut out. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2007 / 126062 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The inner plug having the above-described opening function is set in the cap in advance, and is attached to the container body filled with contents by plugging. However, since the inner plug is provided with a fragile portion that is broken by rotation of the cap, there is a possibility that the fragile portion may break during plugging.

[0005] Therefore, an object of the present invention is to provide a cap structure that has a function of opening the inner plug by rotation of the cap and can be stably attached to a container body by plugging, and a packaging container using the same. [Means for Solving the Problem]

[0006] The cap structure according to the present invention is a cap structure attached to the mouth of a container body, comprising an inner stopper that closes the mouth, and a cap connected to the inner stopper and screwed onto the mouth. The inner stopper has an annular fitting portion that fits onto the open end of the mouth, a partition connected to the fitting portion that closes the inside of the fitting portion, an annular weak portion provided on the partition and having relatively reduced strength, and a projection connected to the portion of the partition surrounded by the weak portion that extends upward toward the fitting portion. The cap has a flat top plate portion having an outlet, a cylindrical peripheral wall portion connected to the outer edge of the top plate portion, an engaging portion provided on the inner surface side of the top plate portion that engages with the projection, and a plurality of columnar ribs, one end of which is connected to the inner surface side of the top plate portion. Relative rotation between the inner stopper and the container body is restricted, and as the cap rotates in the closing direction, the weak portion breaks and the columnar ribs bend due to the downward movement of the projection.

[0007] The packaging container according to the present invention comprises a container body having a cylindrical mouth, an inner stopper that closes the mouth, and a cap connected to the inner stopper and screwed onto the mouth. The inner stopper has an annular fitting portion that fits onto the open end of the mouth, a partition connected to the fitting portion that closes the inside of the fitting portion, an annular weak portion provided on the partition and having relatively reduced strength, and a projection connected to the portion of the partition surrounded by the weak portion that extends toward the cap. The cap has a flat top plate portion having an extraction spout, a cylindrical peripheral wall portion connected to the outer edge of the top plate portion, an engaging portion provided on the inner surface side of the top plate portion that engages with the projection portion, and a plurality of columnar ribs, one end of which is connected to the inner surface side of the top plate portion. Relative rotation between the inner stopper and the container body is restricted, and as the cap rotates in the closing direction, the weak portion breaks and the columnar ribs bend as the projection portion descends. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a cap structure that has the function of opening the inner stopper by rotating the cap and can be stably attached to the container body by pressing it into place, as well as a packaging container using the same. [Brief explanation of the drawing]

[0009] [Figure 1] Longitudinal cross-sectional view of the cap structure according to the embodiment [Figure 2] Cross-sectional view of the cap structure according to the embodiment [Figure 3] Cross-sectional view of the cap structure according to the embodiment [Figure 4] Longitudinal cross-sectional view of the cap structure relating to the comparative example. [Figure 5] A schematic diagram illustrating the deformation of the columnar ribs due to the rotation of the cap. [Figure 6] A schematic diagram showing the positional relationship between the opening of the container body and the internal threads of the cap. [Modes for carrying out the invention]

[0010] Figure 1 is a longitudinal cross-sectional view of the cap structure according to the embodiment. Figures 2 and 3 are cross-sectional views of the cap structure according to the embodiment, corresponding to the cross-section viewed from the line II-II and the cross-section viewed from the line III-III shown in Figure 1(a), respectively.

[0011] The cap structure 1 comprises an inner stopper 3 for closing the mouth 8 of the container body 2, and a cap 4 that screws onto the mouth 8.

[0012] The container body 2 is not particularly limited as long as it has a cylindrical mouth 8 with an external thread 6, but for example, bottles blow-molded from resins such as polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET), bottles formed from multilayer films, glass bottles, laminate tubes, etc. can be used.

[0013] The inner plug 3 comprises a fitting portion 11, a partition wall 12, a fragile portion 13, a protruding portion 14, and a plurality of convex portions 16. The inner plug 3 can be integrally molded by injection molding using, for example, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or a resin mixture thereof.

[0014] The fitting portion 11 is an annular portion that fits onto the open end of the mouth 8 of the container body 2. The fitting portion 11 can be fitted onto the mouth 8 by pressing it into place, and as shown in Figure 1(b), it fits onto the mouth 8 while sandwiching a predetermined range from the open end of the mouth 8. The partition wall 12 is formed continuously with the inner periphery of the annular fitting portion 11 and closes the inside of the fitting portion 11. The partition wall 12 is provided with an annular weak portion 13. The weak portion 13 is a portion of the partition wall 12 whose strength is relatively weaker than other parts, and can be formed, for example, by making it thinner than other parts. The projection 14 is a portion of the partition wall 12 that is connected to the portion surrounded by the weak portion 13 and extends to the opposite side of the mouth of the container body (towards the top plate portion 21 of the cap 4). In this embodiment, the projection 14 has a cylindrical shape and is connected to the partition wall 12 along the weak portion 13 provided on the partition wall 12. The protruding portion 14 is not limited to this, and may, for example, be connected to the partition wall 12 inside the fragile portion 13. Furthermore, a window portion 17 is provided on the peripheral wall of the protruding portion 14, which serves as a flow path for the contents after opening, and a flange portion 15 is provided at the upper end of the protruding portion 14. The flange portion 15 is connected to the upper end of the cylindrical peripheral wall portion and is formed to extend in a direction perpendicular to the central axis of the inner stopper 3 (shown by the dashed line). In this embodiment, the flange portion 15 is provided as a part for engaging with the engaging portion 24 of the cap 4, which will be described later. Instead of providing the flange portion 15 and the window portion 17, the protruding portion 14 may be provided with multiple slits extending in the vertical direction. The convex portion 16 is provided on the upper surface of the fitting portion 11, as shown in Figures 1(a) and 3, and is intermittently arranged at predetermined intervals in the circumferential direction. The convex portion 16 is the part that triggers the deformation of the columnar rib 25 provided on the cap 4, but details will be described later.

[0015] The cap 4 comprises a top plate portion 21, a peripheral wall portion 23, an engaging portion 24, and a plurality of columnar ribs 25. The cap 4 can be integrally molded by injection molding using, for example, polypropylene, high-density polyethylene (HDPE), or LLDPE.

[0016] The top plate portion 21 has a flat plate shape. The top plate portion 21 is provided with a nozzle 27 having a spout 22. The peripheral wall portion 23 is a cylindrical portion connected to the outer peripheral edge of the top plate portion 21. The inner peripheral surface of the peripheral wall portion 23 is provided with an internal thread 7 that screws into the external thread 6 of the mouth portion 8. The engaging portion 24 is the portion that engages with the protruding portion 14 of the inner stopper 3. More specifically, the engaging portion 24 engages with the protruding portion 14 while clamping a predetermined range from the outer peripheral edge of the flange portion 15 of the inner stopper 3. The engagement structure between the cap 4 and the inner stopper 3 is not limited to that shown in Figure 1, and a structure in which the upper end of the protruding portion 14 is clamped and engaged by the engaging portion of the cap 4 without a flange portion 15, or a structure in which the engaging portion of the cap 4 engages with the window portion 17, may also be adopted. The columnar ribs 25 are formed so that one end is connected to the inner surface of the top plate portion 21 and extends in a direction parallel to the central axis of the cap 4 (shown by the dashed line). As shown in Figures 2 and 3, the multiple columnar ribs 25 are intermittently arranged at predetermined intervals in the circumferential direction. In the state shown in Figure 1(a), that is, when the protruding portion 14 of the inner stopper 3 is engaged with the engaging portion 24 of the cap 4 and the container is unopened (the fragile portion 13 is not broken), the other end of the columnar rib 25 (the lower end in Figure 1) is in contact with the upper surface of the fitting portion 11 of the inner stopper 3. Also, in the state shown in Figure 1(b), that is, when the fitting portion 11 of the inner stopper 3 is fitted into the mouth portion 8 of the container body 2 and the container is unopened, the columnar ribs 25 are positioned so as to overlap with the wall portion of the mouth portion 8 in a plan view. In this embodiment, one end of the columnar rib 25 is connected to the engaging portion 24, but the columnar rib 25 may also be connected to other parts of the top plate portion 21. In Figure 1(a), an example is shown in which the other end of the columnar rib 25 abuts against the upper surface of the fitting portion 11, but the columnar rib 25 only needs to support the cap 4 to prevent the fragile portion 13 from breaking when the cap is installed, and there may be a gap between the other end of the columnar rib 25 and the upper surface of the fitting portion 11. Such a gap is preferably 0.5 mm or less.

[0017] The cap structure 1 according to the present embodiment is further provided with an overcap 5 for closing the spout 22 of the cap 4. The overcap 5 is detachably attached to the outer peripheral surface of the nozzle 27 by screwing or fitting. Instead of the cap configuration provided with the overcap 5 as in the present embodiment, it is also possible to employ a hinge cap having a lid that can be opened and closed via a hinge on the top plate portion 21 or the peripheral wall portion 23 of the cap 4. Further, the nozzle 27 is not essential and may be omitted as long as a spout is provided on the top plate portion 21 of the cap 4. Furthermore, when the nozzle 27 is provided, the shape of the nozzle 27 is not particularly limited either.

[0018] As shown in FIG. 1(a), the inner plug 3 is preset in the cap 4. In the present embodiment, as described above, the cap structure 1 in which the inner plug 3 and the cap 4 are integrated can be configured by engaging the protruding portion 14 of the inner plug 3 with the engaging portion 24 of the cap 4.

[0019] A method of attaching the cap structure 1 to the container body 2 will be described.

[0020] The cap structure 1 according to the present embodiment is attached to a container body 2 pre-filled with contents by capping. Capping is performed by applying force to the position indicated by the open arrow shown in FIG. 1(a) in a state where the cap structure 1 and the mouth portion 8 of the container body 2 are aligned. In the cap structure 1 according to the present embodiment, the lower end of the columnar rib 25 provided on the cap 4 is in contact with the upper surface of the fitting portion 11 of the inner plug 3. Note that, as described above, the lower end of the columnar rib 25 and the upper surface of the fitting portion 11 may be in a positional relationship with a gap of, for example, 0.5 mm or less before capping. The columnar rib 25 bridges the top plate portion 21 of the cap 4 and the fitting portion 11 of the inner plug 3 to support the top plate portion 21. Therefore, even when force (impact) is applied to the top plate portion 21 of the cap 4 during capping, the columnar rib 25 supports the top plate portion 21 of the cap 4, and breakage of the fragile portion 13 caused by the force applied during capping can be suppressed. Therefore, with the cap structure 1 according to the present embodiment, efficient capping by capping is enabled, and breakage of the fragile portion 13 caused by capping can be suppressed. In addition, since the top plate portion 21 of the cap 4 is supported by the columnar ribs 25, breakage of the fragile portion 13 due to impact when dropped can also be suppressed. Furthermore, since the lower end of the columnar rib 25 is in contact with the upper surface of the fitting portion 11 during capping, the columnar rib 25 pushes the inner plug 3, so that the inner plug can be more reliably attached to the mouth portion 8.

[0021] Figure 4 is a longitudinal cross-sectional view of a cap structure according to a comparative example.

[0022] The cap structure 1' shown in Figure 4 is configured in the same manner as the cap structure 1 shown in Figure 1, except that the cap 4' does not include the columnar rib 25 shown in Figure 1 and the inner plug 3' does not include the convex portion 16 shown in Figure 1.

[0023] The cap structure 1' shown in Figure 4 does not have columnar ribs. Therefore, if the cap is pressed in with the inner stopper 3' already set in the cap 4', the force applied to the cap 4' for pressing will cause the weak part 13 of the inner stopper 3' to break. For this reason, as shown in Figures 4(a) and 4(b), the cap structure 1' in Figure 4 requires the inner stopper 3' to be attached to the mouth 8 of the container body 2 by pressing, and then the cap 4' to be screwed onto the container body 2. At this time, it is necessary to adjust the amount of rotation of the cap 4' relative to the container body 2 so that the inner stopper 3' and the cap 4' are in a rotational position that engages. Therefore, when using the cap structure 1', the sealing process of the container body 2 is inefficient.

[0024] In contrast, with the cap structure 1 according to this embodiment, it can be attached to the container body 2 by simply pressing it into place, and as shown in the comparative example in Figure 4, there is no need to adjust the amount of rotation of the cap 4, so the cap structure 1 can be attached to the container body 2 efficiently.

[0025] Referring again to Figure 1, the method for opening the cap structure 1 will be explained.

[0026] In the cap structure 1, relative rotation between the inner stopper 3 and the container body 2 is restricted when the inner stopper 3 is fitted into the opening 8. For example, the outer circumferential surface of the portion of the opening 8 of the container body 2 that is clamped by the fitting portion 11, and the inner circumferential surface of the fitting portion 11 that abuts against it, are provided with rotation-preventing knurling (ridges and grooves). Furthermore, in the cap structure 1, relative rotation between the inner stopper 3 and the cap 4 is restricted when the inner stopper 3 and the cap 4 are engaged. For example, the outer circumferential surface of the flange portion 15 of the inner stopper 3 and the inner circumferential surface of the engaging portion 24 that abuts against it, or the upper surface of the flange portion 15 of the inner stopper 3 and the lower surface of the top plate portion 21 that abuts against it, are provided with rotation-preventing knurling (ridges and grooves). In particular, when knurling is provided on the upper surface of the flange portion 15 of the inner stopper 3 and the lower surface of the top plate portion 21 that abuts against it, the cap 4 can be easily lowered while restricting the relative rotation between the inner stopper 3 and the cap 4.

[0027] When opening the container, the user rotates the cap 4 in the closing direction. As the cap 4 rotates in the closing direction, the protruding portion 14 connected to the cap 4 and the portion of the partition wall 12 surrounded by the fragile portion 13 rotate, causing the fragile portion 13 to break. In this embodiment, the protruding portion 14 of the inner stopper 3 is cylindrical, and the lower end of the protruding portion 14 is connected to the partition wall 12 along the fragile portion 13. Therefore, the rotational force of the cap 4 can be transmitted to the fragile portion 13 as a force acting in the circumferential direction of the fragile portion 13. In addition to the force generated by the rotation of the cap 4 that pushes the partition wall 12 inward into the container body 2, the rotational force transmitted in the circumferential direction of the fragile portion 13 allows the fragile portion 13 to break with a small torque. Alternatively, the fragile portion 13 may break as the protruding portion 14 is pushed downward by the cap 4 as it rotates in the closing direction. Furthermore, although the above example shows the lower end of the protruding portion 14 along the weak portion 13, the example is not limited to this, and for example, the lower end of the protruding portion 14 may be connected to the inside of the weak portion 13 with a predetermined gap between them.

[0028] Furthermore, as the cap 4 rotates in the closing direction, the columnar ribs 25 provided on the cap 4 bend. The bending of the columnar ribs 25 will be explained in detail below.

[0029] Figure 5 is a schematic diagram illustrating the deformation of the columnar ribs as the cap rotates.

[0030] Figure 5(a) shows the initial state before the cap 4 is rotated. In this embodiment, a weakened portion 26, which is relatively weaker in strength, is provided near the connection between the columnar rib 25 and the engaging portion 24 of the cap 4. The weakened portion 26 can be formed, for example, by cutting out a part of the columnar rib 25 or by making its thickness smaller than other parts. In addition, the columnar rib 25 shown in Figure 5(a) is formed in a tapered shape, with its thickness decreasing from the connection with the engaging portion 24 of the cap 4 towards the lower end. By forming the columnar rib 25 in a tapered shape, even if a weak portion 13 is provided, it is possible to remove the inner plug 3 from the mold during molding.

[0031] When the cap 4 is rotated in the closing direction (in the direction of the arrow shown in Figure 5), as shown in Figure 5(b), the lower end of the columnar rib 25 comes into contact with the protrusion 16 provided on the upper surface of the fitting portion 11 of the inner stopper 3, and as the cap 4 rotates, the columnar rib 25 begins to bend at the weakened portion 26 provided near the connection portion with the engaging portion 24 of the cap 4. As the rotation angle of the cap 4 increases, the bending of the columnar rib 25 progresses, as shown in Figure 5(c). As the cap 4 rotates, the weak portion 13 provided on the partition wall 12 breaks, and the protruding portion 14 of the inner stopper 3 connected to the cap 4 is pushed into the interior of the container body 2. Note that it is sufficient for the columnar rib 25 to bend down as it rotates the cap 4, and it is not necessary for it to form a protrusion 16.

[0032] Figure 5(d) shows the state after the cap 4 has been tightened, which corresponds to the state shown in Figure 1(c). The columnar rib 25 overcomes the protrusion 16 that it came into contact with at the start of bending and is housed in a bent state within the space enclosed by a pair of adjacent protrusions 16, the upper surface of the fitting portion 11, and the engaging portion 24 (top plate portion 21) of the cap 4.

[0033] Thus, the columnar ribs 25 provided on the cap 4 have the function of suppressing the breakage of the weak part 13 when the cap structure 1 is pressed onto the container body 2, but they bend when the cap 4 is rotated during opening and are housed in the space between the cap 4 and the inner stopper. Therefore, the columnar ribs 25 do not get in the way after opening and do not affect the dispensing of the contents.

[0034] In this embodiment, a weakened portion 26 is provided near the connection between the columnar rib 25 and the engaging portion 24 of the cap 4. Because the columnar rib 25 is easily bent by the weakened portion 26, the increase in torque required to rotate the cap 4 when opening the bottle can be suppressed.

[0035] Returning to Figure 1(c), as the cap 4 rotates in the closing direction, the fragile portion 13 breaks and the columnar rib 25 bends, and as shown in Figure 1(c), the protruding portion 14 and a part of the partition wall 12 connected to it are pushed into the interior of the opening 8. Since a window portion 17 is provided on the peripheral wall of the protruding portion 14, the inside of the container body 2 and the spout 22 are connected through the window portion 17, making it possible to dispense the contents.

[0036] Furthermore, a cylindrical inner ring 28 is provided on the inner surface of the top plate portion 21 of the cap 4 according to this embodiment. As shown in Figure 1(c), when a part of the broken partition wall 12 and the protruding portion 14 are pushed into the opening portion 8, the fitting portion 11 of the inner stopper 3 is housed in the inner ring 28. The inner diameter of the inner ring 28 is set to be the same as or slightly smaller than the outer diameter of the fitting portion 11 of the inner stopper 3, so that the outer circumferential surface of the fitting portion 11 housed in the inner ring 28 and the inner circumferential surface of the inner ring 28 are in close contact. Therefore, after the inner stopper 3 is opened, the close contact between the fitting portion 11 and the inner ring 28 seals the space between the cap 4 and the inner stopper 3, thereby improving the airtightness of the contents.

[0037] The following describes the structure that defines the rotational position of the cap 4 relative to the container body 2.

[0038] Figure 6 schematically shows the positional relationship between the mouth of the container body and the internal thread of the cap. Figure 6 corresponds to a view of the external thread 6 and internal thread 7 seen through the peripheral wall 23 of the cap 4. Also, the inner stopper 3 is omitted from the description in Figure 6.

[0039] The internal thread 7, located on the inner surface of the peripheral wall portion 23 of the cap 4, has skipped thread portions 9a and 9b. These skipped thread portions 9a and 9b can be formed, for example, by partially cutting out the threads of the internal thread 7 or by partially reducing the height of the threads of the internal thread 7. On the other hand, the outer surface of the mouth portion 8 of the container body 2 has engagement ribs 10a to 10c in the portion adjacent to the threads of the external thread 6. The engagement ribs 10a to 10c extend parallel to the central axis of the container body 2 and can be formed as protrusions having approximately the same height as the threads of the external thread 6.

[0040] Figure 6(a) shows the initial state of the cap structure 1 before opening, that is, the state in which the fitting portion 11 of the inner stopper 3 is fitted into the opening portion 8 and the fragile portion 13 has not broken. In this state, the rotation of the cap 4 is restricted by the engagement of the engagement ribs 10a and 10b of the outer thread 6, respectively, with the jumping screw portions 9a and 9b of the inner thread 7 engaging with each other. This prevents unexpected rotation of the cap 4 during transportation of the packaging container to which the cap structure 1 is attached, and maintains the unopened state. However, if the cap 4 is rotated by applying a torque above a certain level, the jumping screw portions 9a and 9b will overcome the engagement ribs 10a and 10b, allowing the cap 4 to rotate further in the closing direction.

[0041] Figure 6(b) shows the state in which the fragile portion 13 is broken and the cap 4 is tightened. In this state, the rotation of the cap 4 is restricted by the engagement of the engagement ribs 10b and 10c of the external thread 6, respectively, with the jumping screw portions 9a and 9b of the internal thread 7 engaging with each other. This prevents the cap 4 from loosening, maintaining the position of a part of the partition wall and the protruding portion 14 of the inner stopper 3 separated from the fitting portion 11 in the position shown in Figure 1(c), making it possible to stably dispense the contents. In addition, when the cap 4 is tightened during opening, a click sensation is created as the jumping screw portions 9a and 9b and the engagement ribs 10b and 10c change from a disengaged state to an engaged state, informing the user that the rotation operation is complete.

[0042] In the example shown in Figure 6, two skipped thread sections 9a and 9b are provided on the internal thread 7, but the number of skipped thread sections can be appropriately changed according to the number of threads in the internal thread 7. Also, the engagement ribs 10a to 10c provided on the mouth 8 of the container body 2 are provided at one location in the circumferential direction of the mouth 8, but depending on the number of threads, the engagement ribs may be provided at multiple locations in the circumferential direction of the mouth 8. Furthermore, only the engagement rib 10a may be provided to suppress the rotation of the cap 4 in the initial state, and the tightening completion position when closing may be free (arbitrary).

[0043] As described above, according to this embodiment, a cap structure 1 that can be stably attached to the container body 2 by pressing, while having the function of opening the inner stopper 3 by rotating the cap 4, and a packaging container using the same can be realized. [Industrial applicability]

[0044] This invention can be used for packaging containers such as condiment containers. [Explanation of Symbols]

[0045] 1 Cap structure 2. Container body 3. Inner stopper 4 caps 6 External threads 7 Internal thread 8 Mouth 9. Flying screw section 11 Fitting part 12 Bulkhead 13 Vulnerable parts 14 Protrusion 16 Convex part 21 Top panel 22 Spout 23 Peripheral wall section 24 Engagement part 25 Columnar Ribs 26 Weakened part 28 Inner Rings

Claims

1. A cap structure that is attached to the mouth of the container body, An inner stopper that closes the opening, It comprises a cap that is connected to the aforementioned inner stopper and screwed onto the mouth portion, The aforementioned stopper is An annular fitting portion that fits into the open end of the mouth, A partition wall connected to the fitting portion and closing the inside of the fitting portion, An annular, weakened portion is provided in the partition wall, The partition wall has a projection that is connected to the portion surrounded by the weak portion and extends upward toward the fitting portion, The aforementioned cap is A flat top plate having an extraction opening, A cylindrical peripheral wall portion connected to the outer edge of the top plate portion, An engaging portion is provided on the inner surface side of the top plate portion and engages with the protruding portion, It has a plurality of columnar ribs, one end of which is connected to the inner surface of the top plate portion, The relative rotation between the stopper and the container body is restricted. A cap structure in which the weak portion breaks and the columnar rib bends as the protruding portion descends due to the rotation of the cap in the closing direction.

2. The cap structure according to claim 1, wherein a weakened portion with relatively reduced strength is provided near one end of the columnar rib.

3. An annular inner ring capable of accommodating the fragile part is provided on the inner surface of the top plate portion of the cap. The cap structure according to claim 1 or 2, wherein, after the fragile portion breaks, as the cap rotates in the closing direction, the fitting portion is housed within the inner ring, and the outer circumferential surface of the fitting portion and the inner circumferential surface of the inner ring come into close contact.

4. The cap structure according to claim 1, wherein the inner stopper has a plurality of protrusions provided on the upper surface of the fitting portion and arranged at predetermined intervals in the circumferential direction.

5. The cap structure according to claim 4, wherein the columnar rib is bent and accommodated in the space between the plurality of protrusions.

6. The cap structure according to claim 1, wherein as the cap rotates in the closing direction, the portion of the partition wall surrounded by the protruding portion and the fragile portion rotates relative to the other portions of the partition wall.

7. A container body having a cylindrical opening, An inner stopper that closes the opening, It comprises a cap that is connected to the aforementioned inner stopper and screwed onto the mouth portion, The aforementioned stopper is An annular fitting portion that fits into the open end of the mouth, A partition wall connected to the fitting portion and closing the inside of the fitting portion, An annular, weakened portion is provided in the partition wall, The partition wall has a projection that is connected to the portion surrounded by the weak part and extends toward the cap, The aforementioned cap is A flat top plate having an extraction opening, A cylindrical peripheral wall portion connected to the outer edge of the top plate portion, An engaging portion is provided on the inner surface side of the top plate portion and engages with the protruding portion, It has a plurality of columnar ribs, one end of which is connected to the inner surface of the top plate portion, The relative rotation between the stopper and the container body is restricted. A packaging container in which the fragile portion breaks and the columnar rib bends as the protruding portion descends due to the rotation of the cap in the closing direction.

8. The outer surface of the mouth of the container body is provided with an external thread, and the inner surface of the peripheral wall of the cap is provided with an internal thread that engages with the external thread. A section of the internal thread is provided in the middle of the thread, in which a portion of the thread is cut out. An engaging rib is provided on the outer surface of the opening adjacent to the screw threads, which engages with the protruding screw portion. The packaging container according to claim 7, wherein the engaging rib restricts the rotation of the cap in both the state where the fitting portion of the inner stopper is fitted to the opening and the fragile portion has not broken, and the state where the cap is tightened until the fragile portion breaks.

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