Stopper and packaging container

Abstract

To enable a separated band part to drop smoothly.SOLUTION: A plug comprises a spout, a cap, a band part and a fracturing part. The band part has a band main body in a cylindrical shape, a plurality of flaps which extend from a lower end part of the band main body and contact a lower surface of the notch to restrict the cap from separating from the spout, and a plurality of thin parts which are smaller in thickness than the plurality of flaps. The fracturing part connects the band main body to one end of the peripheral wall so that the band part is separated from the cap when the cap is removed from the spout. Between a lower end of the band part and a portion of the flange of the spout facing the lower end of the band part is formed a clearance. The plurality of flaps are arranged along a circumferential direction. Each of the plurality of thin parts connects the flaps arranged adjacent to each other, of the plurality of flaps, to each other.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a stopper and a packaging container.

Background Art

[0002] Patent Document 1 discloses a nozzle structure of a bottle with enhanced tamper-evident function. Patent Document 2 discloses a composite container lid composed of a combination of a lid body, an inner lid made of a thin metal plate, and an upper lid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a stopper and a packaging container in which a separated band portion can fall smoothly.

Means for Solving the Problems

[0005] The stopper according to one aspect of the present disclosure includes a spout, a cap, a band portion, and a breaking portion. The spout has a cylindrical side wall, an external thread provided on the outer peripheral surface of the side wall, a flange provided on one end side of the side wall, and a notch formed so as to protrude outward from the side wall. The cap has a top plate, a peripheral wall connected to the outer peripheral edge of the top plate, and an internal thread provided on the inner peripheral surface of the peripheral wall and screwed with the external thread. The band portion has a cylindrical band body, and a plurality of flaps that incline and extend from the lower end portion of the band body toward the top plate and regulate the separation of the cap from the spout by contacting the lower surface of the notch, and a plurality of thin portions having a thickness smaller than that of the plurality of flaps. The breaking portion connects the band body and one end of the peripheral wall so that the band portion and the cap are separated when the cap is removed from the spout. A gap is provided between the lower end of the band portion and the portion of the flange facing the lower end of the band portion. The plurality of flaps are arranged along the circumferential direction around the central axis of the cap. Each of the plurality of thin portions connects adjacent flaps among the plurality of flaps.

[0006] In the flap, a restoring force that tries to fall toward the spout may occur, and due to the restoring force, the flap sandwiches the spout, so that when the cap is removed, the band portion may not fall downward. In the above stopper, adjacent flaps are connected by a thin portion. Therefore, even if any one of the flaps tries to fall due to the restoring force toward the central axis, the movement of trying to fall is restricted. As a result, the possibility that the flap falls toward the central axis and sandwiches the spout can be reduced. Therefore, in the above stopper, the separated band portion can fall smoothly.

[0007] The ratio of the thickness of the plurality of flaps to the thickness of the plurality of thin portions may be 1.5 to 5.0. When the ratio is 1.5 or more, the processing of the flap becomes easy. Further, when the ratio is 5.0 or less, the fall due to the restoring force that may occur in the flap can be more reliably suppressed.

[0008] The thickness of the plurality of thin portions may be 0.15 mm to 0.35 mm. The thickness of the plurality of flaps may be 0.6 mm to 0.8 mm. By the thickness being 0.15 mm or more, it is possible to more reliably suppress the collapse due to the restoring force that can occur in the flap. By the thickness being 0.35 mm or less, the processing of the flap is easy.

[0009] Each of the plurality of flaps may be formed such that the width decreases from the tip toward the lower end of the band body. In this case, when removing the cap, bending processing at the base of the flap is easy while maintaining the range where the plurality of flaps contact the notch.

[0010] The number of the plurality of flaps may be 8 to 12. By the number of the plurality of flaps being 8 or more, the flaps are likely to catch on the notch and a force to break the breaking portion is likely to be generated when removing the cap. Also, by the number of the plurality of flaps being 12 or less, the bending processing of the plurality of flaps is easy.

[0011] The plurality of flaps may be arranged so as to face the lower surface of the notch in a state separated from the spout. Since the flaps are arranged in a state separated from the spout, it is difficult for the flaps to contact the spout when the cap is removed. Therefore, the separated band portion can fall more smoothly.

[0012] In the longitudinal section including the central axis, the distance d1 in the direction orthogonal to the central axis between one of the plurality of flaps and the side wall of the spout may be 0.3 mm to 0.7 mm. By the distance d1 being 0.3 mm or more, it is possible to more reliably avoid the contact between the flap and the spout. Also, by the distance d1 being 0.7 mm or less, it is possible to reduce the possibility that the tip of the flap is not caught by the notch when removing the cap, and the function of the flap can be more reliably exhibited.

[0013] In the longitudinal section including the above central axis, the distance d2 in the direction orthogonal to the above central axis between point A located at the outermost side of the notch and point B located at the innermost side of one of the plurality of flaps may be 0.5 mm to 0.9 mm. Since the distance d2 is 0.5 mm or more, the possibility that the tip of the flap is not caught by the notch when removing the cap can be reduced, and the function of the flap can be more reliably exhibited. Also, since the distance d2 is 0.9 mm or less, contact between the flap and the spout can be more reliably avoided.

[0014] In the longitudinal section including the above central axis, the width wb along the direction orthogonal to the above central axis of the portion of the side wall located below the notch may be 1.0 mm to 1.4 mm. Since the width wb is 1.0 mm or more, the strength of the spout can be maintained. Since the width wb is 1.4 mm or less, contact between the flap and the spout can be more reliably avoided.

[0015] In the longitudinal section including the above central axis, the distance xb in the direction orthogonal to the above central axis between the portion of the side wall located below the notch and point A located at the outermost side of the notch may be larger than the distance xa in the direction orthogonal to the above central axis between the portion of the side wall located above the notch and point A located at the outermost side of the notch. In this case, the possibility of contact between the flap and the spout can be reduced.

[0016] The ratio of the distance xb to the distance xa may be 1.5 or more. Since the above ratio is 1.5 or more, the possibility of contact between the flap and the spout can be further reduced.

[0017] The distance xb may be 1.0 mm to 1.4 mm. Since the distance xb is 1.0 mm or more, the possibility of contact between the flap and the spout can be further reduced. Also, since the distance xb is 1.4 mm or less, the strength of the spout can be maintained.

[0018] The notch may include a protruding portion that forms a side surface extending along the central axis, and an inclined surface that extends from the lower surface of the protruding portion and is inclined with respect to the outer peripheral surface of the side wall. In this case, even if the flap falls toward the spout due to the restoring force, the tip of the flap can contact the inclined surface. Contact with the inclined surface makes the flap slippery, so that the band portion can fall smoothly. Therefore, the possibility that the band portion remains in its original position can be reduced.

[0019] Each of the plurality of flaps may include a base end portion connected to the lower end portion of the band body and formed to curve downward, and an inclined portion connected to the base end portion and formed to extend toward the top plate. In the longitudinal section including the central axis, the radius of curvature of the upper surface of the base end portion may be 0.55 mm to 0.75 mm. By the radius of curvature being 0.55 mm or more, the possibility that the tip of the flap is not caught by the notch when removing the cap can be reduced, and the function of the flap can be more reliably exhibited. By the radius of curvature being 0.75 mm or less, the degree of deformation increases, and the restoring force generated in the inclined portion can be reduced.

[0020] Each of the plurality of flaps may include a base end portion connected to the lower end portion of the band body and formed to curve downward, and an inclined portion connected to the base end portion and formed to extend toward the top plate. In the longitudinal section including the central axis, the minimum value of the inclination angle of the side surface facing the central axis among the inclined portions with respect to the direction orthogonal to the central axis may be 50° or more. By the minimum value of the inclination angle being 50° or more, the possibility of contact between the flap and the spout can be reduced.

[0021] The packaging container according to one aspect of the present disclosure includes any one of the above-mentioned stoppers and a container body to which the stopper is attached. In this packaging container, since any one of the above-mentioned stoppers is provided, the separated band portion can fall smoothly.

Advantages of the Invention

[0022] According to the present disclosure, there are provided a stopper in which a separated band portion can fall smoothly, and a packaging container.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0024] Hereinafter, some embodiments will be described with reference to the drawings. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following content. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant descriptions may be omitted as appropriate. The dimensional ratios of the respective elements are not limited to the ratios shown in the drawings. In some of the drawings, an orthogonal coordinate system defined by the X-axis, Y-axis, and Z-axis is shown.

[0025] FIG. 1 shows a perspective view of a packaging container according to an embodiment. The packaging container 1 is a container for containing contents. The contents contained in the packaging container 1 may be in a liquid state, and specific examples thereof include alcoholic beverages, drinks, and seasonings. The packaging container 1 includes a container body 2 and a stopper 4. The container body 2 is a main body portion for containing contents such as a liquid. Examples of the material of the container body 2 include paper, resin, and glass. The material of the container body 2 may be a laminate of paper and resin. The stopper 4 is attached to the container body 2.

[0026] (Stopper) The stopper 4 is a member for forming a spout for pouring out the contents from the packaging container 1 (container body 2). FIGS. 2(a) and 2(b) show side views of the stopper 4. FIG. 3 shows a longitudinal section of the stopper 4 shown in FIG. 2(a). As shown in FIGS. 2(a), 2(b), and 3, the stopper 4 includes a cap 10, a spout 30, and a band portion 40. The cap 10 is fixed (attached) to the spout 30.

[0027] The cap 10, the spout 30, and the band portion 40 may all be made of resin. For example, the cap 10 and the band portion 40 may be made of polypropylene resin. The spout 30 may be made of low-density polyethylene resin, and among them, it may be made of linear low-density polyethylene resin. Hereinafter, each of the cap 10, the spout 30, and the band portion 40 will be described. In the following description, with reference to the central axis Ax of the cap 10 (see FIG. 3), the direction toward the central axis Ax is defined as "inward", the direction away from the central axis Ax is defined as "outward", the direction along the central axis Ax is defined as "vertical direction", the direction in which the cap 10 moves away from the spout 30 is defined as "upward", and the direction in which the cap 10 approaches the spout 30 is defined as "downward".

[0028] The cap 10 has a top plate 12, a peripheral wall 14, an internal thread 15, and an inner ring 16. The top plate 12 is formed in a disc shape. A tapered portion 18 is formed on the outer peripheral edge of the top plate 12. The peripheral wall 14 extends downward from the tapered portion 18 and has a cylindrical shape. The upper end of the peripheral wall 14 is connected to the outer peripheral edge of the top plate 12. The central axis Ax of the cap 10 may pass through the center of the top plate 12 and be orthogonal to the upper surface of the top plate 12. A knurl 20 is formed on the outer peripheral surface of the peripheral wall 14.

[0029] The knurl 20 is constituted by, for example, a plurality of protrusions 22 and a plurality of bases 24. The plurality of protrusions 22 and the plurality of bases 24 are arranged alternately one by one along the circumferential direction centered on the central axis Ax of the cap 10. That is, in the above circumferential direction, each protrusion 22 is sandwiched between a pair of bases 24, and each base 24 is sandwiched between a pair of protrusions 22. In a plan view of the cap 10 (when viewed from above along the central axis Ax), the outer edge of the protrusion 22 may be serrated.

[0030] In a plan view of the cap 10, the outer edge of the base 24 may be located inside a virtual circle connecting the tops of the outer edges of the plurality of protrusions 22. The outer edge of the base 24 may be curved, straight, or serrated. The shape of the knurl 20 is not limited to the examples shown in FIGS. 2(a) and 2(b), and the knurl 20 may be formed in any manner from the viewpoint of improving the operability of the cap 10.

[0031] The peripheral wall 14 may include a base portion 28 provided below the knurling 20. The base portion 28 has a cylindrical shape. A band portion 40 is connected to the lower end of the base portion 28. By providing the base portion 28, the molding of the cap 10 and the connection with the band portion 40 can be facilitated. In the present disclosure, being connected (attached) to a member includes not only the case of being directly connected to the member but also the case of being connected (attached) via another fixing member. The knurling 20 is formed between the lower end of the tapered portion 18 and the upper end of the base portion 28. Different from the examples shown in FIGS. 2(a) and 2(b), the cap 10 may not have the tapered portion 18 and may not have the base portion 28. The knurling 20 may be formed over the entire peripheral wall 14 of the cap 10.

[0032] As shown in FIG. 3, the internal thread 15 is provided on the inner peripheral surface of the peripheral wall 14. The inner ring 16 is provided on the inner surface (lower surface) of the top plate 12. The inner ring 16 extends along the central axis Ax from the inner surface of the top plate 12 and has a cylindrical shape. The inner ring 16 is disposed inside the peripheral wall 14 with a gap provided between the inner ring 16 and the peripheral wall 14.

[0033] The spout 30 has a side wall 32, an external thread 33, and a flange 34. The side wall 32 has a cylindrical shape. The diameter of the side wall 32 is smaller than the diameter of the peripheral wall 14 of the cap 10. That is, the distance between the side wall 32 and the central axis Ax is smaller than the distance between the peripheral wall 14 and the central axis Ax. The external thread 33 is provided on the outer peripheral surface of the upper half of the side wall 32. The internal thread 15 formed on the peripheral wall 14 of the cap 10 is screwed onto the external thread 33. The upper end portion (the upper end and its vicinity) of the side wall 32 is inserted between the peripheral wall 14 and the inner ring 16. The side wall 32 and the external thread 33 are in close contact with the peripheral wall 14, the internal thread 15, and the inner ring 16 at a plurality of locations. Thereby, leakage of the content (for example, liquid leakage) from between the spout 30 and the cap 10 is prevented.

[0034] The flange 34 is provided at one end side of the side wall 32. The flange 34 is connected to the lower end portion of the side wall 32 and extends outward from the side wall 32. The flange 34 is formed in an annular shape. The flange 34 is a joint portion when attaching the plug 4 to the container body 2. The flange 34 may include an upper surface 34a to which the packaging material of the container body 2 is joined. The joining of the packaging material and the flange 34 may be performed by ultrasonic welding, adhesion, or the like. The flange 34 includes a portion where the upper surface 34a is formed (hereinafter referred to as "flange portion 35") and a ring portion 36 that connects the flange portion 35 and the lower end portion of the side wall 32. The ring portion 36 is disposed inside the flange portion 35 and is connected to, for example, the side surface of the lower end portion of the side wall 32.

[0035] The spout 30 has a notch 38. The notch 38 is formed on the outer peripheral surface of the side wall 32 and is formed to protrude outward from the side wall 32. The notch 38 is formed in an annular shape and is continuously provided along the circumferential direction around the central axis Ax on the outer peripheral surface of the side wall 32. The notch 38 is located below the external thread 33 and is provided at the central portion in the vertical direction of the side wall 32. The notch 38 has a function of restricting the movement of the band portion 40.

[0036] The band portion 40 is attached to the lower end of the peripheral wall 14 of the cap 10. The band portion 40 is connected to, for example, the lower end of the base portion 28 included in the peripheral wall 14. The band portion 40 has a cylindrical shape. The outer diameter of the band portion 40 substantially coincides with the outer diameter of the peripheral wall 14 of the cap 10. The band portion 40 is disposed between the peripheral wall 14 and the spout 30 (for example, the ring portion 36) and restricts the cap 10 from separating from the spout 30.

[0037] As shown in FIG. 2(a), a gap g is formed between the lower end of the band portion 40 and the portion of the flange 34 of the spout 30 that faces the lower end of the band portion 40. For example, a gap g is provided between the lower end of the band portion 40 and the ring portion 36 of the flange 34. The gap g is formed for the purpose of preventing tampering. The band portion 40 is connected to the peripheral wall 14 such that when the cap 10 in the unopened state (the initial state in which the cap 10 has never been removed) is removed from the spout 30, the band portion 40 and the cap 10 are separated. When the band portion 40 and the cap 10 are separated (detached), they are in a state where they are not connected to each other. In this case, when the cap 10 is removed from the spout 30 and opened, the band portion 40 remains on the spout 30.

[0038] The band portion 40 separated from the cap 10 can move downward so that its lower end abuts against the ring portion 36 of the flange 34. The gap g is formed such that when the band portion 40 is separated from the cap 10, the band portion 40 drops downward. When the once-opened cap 10 is reattached to the spout 30, as shown in FIG. 2(b), a gap g1 is formed between the lower end of the cap 10 and the upper end of the band portion 40 remaining on the spout 30. The size (width) of the gap g1 substantially coincides with the size (width) of the gap g in the unopened state. After being opened once, a gap is formed between the lower end of the cap 10 and the upper end of the band portion 40, so that it can be visually confirmed that the cap 10 has already been opened.

[0039] The size of the gap g (the size of the gap g1) may be 0.5 mm or more. The size of the gap g is defined by the shortest distance between the lower end of the band portion 40 and the upper end of the ring portion 36. From the viewpoint of visibility (more specifically, the visibility of the gap after opening), the size of the gap g may be 0.7 mm or more, 0.8 mm or more, 0.9 mm or more, or 1.0 mm or more. From the viewpoint of ensuring the size of the cap 10 (the length along the central axis Ax), the size of the gap g may be 2.0 mm or less, 1.8 mm or less, 1.6 mm or less, or 1.4 mm or less.

[0040] Figure 4 shows a bottom view when looking at the band portion 40 from below along the central axis Ax, and some elements of the cap 10 and the illustration of the spout 30 are omitted. In the left half of Figure 3, a cross-section along line IIIA in Figure 4 is shown, and in the right half of Figure 3, a cross-section along line IIIB in Figure 4 is shown. The band portion 40 has a band main body 41, a plurality of flaps 42, and a plurality of thin-walled portions 48. The band main body 41 is disposed below the peripheral wall 14 of the cap 10 and has a cylindrical shape. The outer diameter of the band main body 41 may substantially coincide with the outer diameter of the peripheral wall 14 (the base portion 28 of the peripheral wall 14).

[0041] The flap 42 is connected to the lower end portion of the band main body 41 and extends from the lower end portion toward the top plate 12 of the cap 10. The flap 42 is inclined with respect to the central axis Ax and a plane perpendicular to the central axis Ax (the X-Y plane in the figure). The flap 42 is formed such that the distance between the central axis Ax and the flap 42 decreases as it approaches the top plate 12.

[0042] The plurality of flaps 42 have a function of restricting the cap 10 from moving relatively away from the spout 30. At least a part of the tip 42a (upper end surface) of the flap 42 faces the lower surface 38a of the notch 38 of the spout 30. When attempting to remove the cap 10, each flap 42 abuts against the lower surface 38a of the notch 38, thereby restricting the cap 10 from moving relatively away from the spout 30.

[0043] The flap 42 may be arranged to face the lower surface 38a of the notch 38 in a state separated from the spout 30. Any part of the flap 42 may be formed so as not to contact the side wall 32 and the notch 38. The tip 42a (upper end surface) of the flap 42 may be separated from the spout 30. When the tip 42a of the flap 42 is separated from the spout 30, the tip 42a of the flap 42 does not contact the side wall 32 and the notch 38 of the spout 30. The tip 42a of the flap 42 may not contact the inner peripheral surface of the band body 41 (may also be separated from the inner peripheral surface of the band body 41) in addition to the spout 30.

[0044] Each flap 42 includes a base end portion 43 connected to the lower end portion of the band body 41 and curved downward, and an inclined portion 44 connected to the base end portion 43 and formed to extend toward the top plate 12. By the base end portion 43 curving downward, the base end portion 43 has a shape convex downward. The tip of the inclined portion 44 (the end surface on the side opposite to the end surface connected to the base end portion 43) corresponds to the tip 42a of the flap 42.

[0045] As shown in FIG. 4, the plurality of flaps 42 are arranged along the circumferential direction around the central axis Ax. The plurality of flaps 42 are arranged at intervals from each other in the circumferential direction around the central axis Ax (provided at a predetermined interval). The number of the plurality of flaps 42 may be 8. Different from the example shown in FIG. 4, the number of the plurality of flaps 42 may be 9 to 12. Each flap 42 is formed in a plate shape so as to extend along the circumferential direction around the central axis Ax. The plurality of flaps 42 may have the same shape as each other.

[0046] Each of the plurality of thin portions 48 connects the flaps 42 adjacent to each other in the circumferential direction around the central axis Ax among the plurality of flaps 42. One flap 42 and one thin portion 48 are alternately arranged in the circumferential direction around the central axis Ax. One thin portion 48 connects (joins) a pair of flaps 42 sandwiching itself in the circumferential direction around the central axis Ax. The thin portion 48 is formed in a plate shape so as to extend along the circumferential direction around the central axis Ax. The plurality of thin portions 48 may have the same shape as each other.

[0047] The thickness Th2 of the plurality of thin portions 48 is smaller than the thickness Th1 of the plurality of flaps 42 (see also FIGS. 6(a) and 6(b)). The thicknesses Th2 of the plurality of thin portions 48 may be substantially the same as each other, and the thicknesses Th1 of the plurality of flaps 42 may be substantially the same as each other. The ratio of the thickness Th1 of the flap 42 to the thickness Th2 of the thin portion 48 may be 5.0 or less, 4.5 or less, 4.0 or less, or 3.5 or less from the viewpoint of suppressing the restoring force of the flap 42. The ratio of the thickness Th1 of the flap 42 to the thickness Th2 of the thin portion 48 may be 1.5 or more, 2.0 or more, 2.5 or more, or 3.0 or more from the viewpoint of ease of processing of the flap 42. The ratio of the thickness Th1 of the flap 42 to the thickness Th2 of the thin portion 48 may be 1.5 to 5.0, or 2.0 to 4.5.

[0048] The thickness Th2 of the thin portion 48 may be 0.15 mm or more, 0.18 mm or more, 0.20 mm or more, or 0.22 mm or more from the viewpoint of suppressing the restoring force of the flap 42. The thickness Th2 of the thin portion 48 may be 0.35 mm or less, 0.32 mm or less, 0.30 mm or less, or 0.28 mm or less from the viewpoint of ease of processing of the flap 42. The thickness Th2 of the thin portion 48 may be 0.15 mm to 0.35 mm, or 0.22 mm to 0.28 mm. The thickness Th2 of the thin portion 48 may be measured at the tip of the thin portion 48 (the tip surface located on the side opposite to the band body 41).

[0049] The thickness Th1 of the flap 42 may be 0.60 mm or more, 0.62 mm or more, 0.64 mm or more, or 0.65 mm or more from the viewpoint of enabling the flap 42 to function. The thickness Th1 of the flap 42 may be 0.80 mm or less, 0.78 mm or less, 0.76 mm or less, or 0.75 mm or less from the viewpoint of ease of processing of the flap 42. The thickness Th1 of the flap 42 may be 0.6 mm to 0.8 mm, or may be 0.65 mm to 0.75 mm. The thickness Th1 of the flap 42 may be measured at the tip of the flap 42 (the tip surface located on the side opposite to the band body 41).

[0050] Each of the plurality of flaps 42 may be formed such that the width decreases from the tip (the end close to the central axis Ax) toward the lower end of the band body 41. As shown in FIG. 4, when viewed from below along the central axis Ax, the width along the circumferential direction around the central axis Ax of the flap 42 decreases from the inside to the outside. When viewed from below along the central axis Ax, the length of the line segment connecting both ends of the inner peripheral edge 47a of the flap 42 is smaller than the length of the line segment connecting both ends of the outer peripheral edge 47b of the flap 42. The length of the line segment connecting both ends of the outer peripheral edge 47b may be 1 / 5 to 4 / 5 times the length of the line segment connecting both ends of the inner peripheral edge 47a. The distance between the pair of side edges 47c connecting the inner peripheral edge 47a and the outer peripheral edge 47b decreases as the distance from the central axis Ax increases.

[0051] The thin portion 48 may not be connected to the tip (inner peripheral edge 47a) of the flap 42. When viewed from below along the central axis Ax, the amount of protrusion y1 of the flap 42 from the inner peripheral surface of the band body 41 is larger than the amount of protrusion y2 of the thin portion 48 from the inner peripheral surface of the band body 41. The amount of protrusion y2 may be 0.7 times to 0.95 times the amount of protrusion y1.

[0052] Figure 5 shows an enlarged cross-sectional view of the area surrounded by the V line in Figure 3. Figures 3 and 5 show longitudinal cross-sections when the stopper 4 is cut along a plane that includes the central axis Ax and passes through any one of the flaps 42. Hereinafter, a longitudinal cross-section that includes the central axis Ax and passes through the flap 42 is referred to as an "observation cross-section". The observation cross-section may be set so as to include the central axis Ax and pass through the center of the circumference around the central axis Ax of the flap 42. In the observation cross-section, the direction perpendicular to the central axis Ax is defined as the "lateral direction". In the example shown in Figure 5, the observation cross-section corresponds to the X-Z plane, and the lateral direction corresponds to the X-axis direction.

[0053] In the observation cross-section, the lateral distance d1 between the flap 42 and the spout 30 may be 0.30 mm or more, 0.35 mm or more, 0.40 mm or more, or 0.45 mm or more from the viewpoint of more surely avoiding contact between the flap 42 and the spout 30. The distance d1 may be 0.70 mm or less, 0.65 mm or less, 0.60 mm or less, or 0.55 mm or less from the viewpoint of enabling the flap 42 to function. The distance d1 may be 0.3 mm to 0.7 mm, or may be 0.45 mm to 0.55 mm. The distance d1 is defined as the shortest lateral distance between the flap 42 and the spout 30. In the example shown in Figure 5, the distance d1 corresponds to the shortest lateral distance between the tip 42a of the flap 42 and the spout 30.

[0054] In the observation cross-section, the lateral distance d2 between the point A located at the outermost side of the notch 38 and the point B located at the innermost side of the flap 42 may be 0.50 mm or more, 0.55 mm or more, 0.60 mm or more, or 0.65 mm or more from the viewpoint of enabling the flap 42 to function. The lateral distance d2 between the point A and the point B may be 0.9 mm or less, 0.85 mm or less, 0.80 mm or less, or 0.75 mm or less from the viewpoint of more surely avoiding contact between the flap 42 and the spout 30. The distance d2 may be 0.5 mm to 0.9 mm, or may be 0.65 mm to 0.75 mm.

[0055] In the observation cross-section, the minimum value of the inclination angle with respect to the lateral direction of the side surface facing the central axis Ax of the inclined portion 44 (the portion corresponding to the inclined portion 44 among the side surfaces 45 of the flap 42) may be 50° or more, 55° or more, 60° or more, or 65° or more from the viewpoint of more surely avoiding contact between the flap 42 and the spout 30. The minimum value of the inclination angle may be 85° or less from the viewpoint of enabling the flap 42 to function. The maximum value of the inclination angle may be 85° or less. When the side surface facing the central axis Ax of the inclined portion 44 has a plurality of inclination angles, the plurality of inclination angles (the minimum angle among the plurality of inclination angles) may be 50° or more, or may be 50° to 85°. In the example shown in FIG. 5, the plurality of inclination angles are indicated by "θ1" and "θ2", and the inclination angle θ2 is smaller than the inclination angle θ1. The inclination angle θ2 may be 50° or more.

[0056] Here, a portion of the side wall 32 of the spout 30 located above the notch 38 is defined as an "upper portion 32a", and a portion located below the notch 38 is defined as a "lower portion 32b". The notch 38 may include a protruding portion 39a extending along the central axis Ax and forming a side surface 37a facing the inner peripheral surface of the band body 41, and an inclined portion 39b forming an inclined surface 37b extending from the upper end of the side surface 37a of the protruding portion 39a to the upper portion 32a in an inclined state. The upper portion 32a of the side wall 32 is located above the upper end of the inclined portion 39b, and the lower portion 32b of the side wall 32 is located below the lower end of the protruding portion 39a.

[0057] In the observation cross-section, the width wb along the lateral direction of the lower portion 32b may be 1.40 mm or less, 1.35 mm or less, 1.30 mm or less, or 1.25 mm or less from the viewpoint of more surely avoiding contact between the flap 42 and the spout 30. The width wb may be 1.0 mm or more, 1.05 mm or more, 1.10 mm or more, or 1.15 mm or more from the viewpoint of the strength of the spout 30. The width wb may be 1.0 mm to 1.4 mm, or may be 1.15 mm to 1.25 mm. The width wb may be smaller than the width wa of the upper portion 32a. The width wb may be 0.5 times to 0.8 times the width wa.

[0058] In the observation cross-section, the lateral distance xb (the shortest distance in the lateral direction) between the lower portion 32b and the outermost point A of the notch 38 may be greater than the lateral distance xa (the shortest distance in the lateral direction) between the upper portion 32a and the point A. From the perspective of more reliably avoiding contact between the flap 42 and the spout 30, the ratio of the distance xb to the distance xa may be 1.5 or more, 1.6 or more, 1.7 or more, or 1.8 or more. From the perspective of ease of manufacturing the spout 30, the ratio of the distance xb to the distance xa may be 3.0 or less.

[0059] The widthwise distance xb between the lower portion 32b and the point A may be 1.00 mm or more, 1.05 mm or more, 1.10 mm or more, or 1.15 mm or more from the perspective of more reliably avoiding contact between the flap 42 and the spout 30. From the perspective of the strength of the spout 30, the distance xb may be 1.40 mm or less, 1.35 mm or less, 1.30 mm or less, or 1.25 mm or less. The distance xb may be 1.0 mm to 1.4 mm, or may be 1.15 mm to 1.25 mm. The widthwise distance xa between the upper portion 32a and the point A may be 0.4 mm to 0.8 mm.

[0060] FIG. 6(a) schematically shows an example of the state when the flap 42 is formed. FIG. 6(b) schematically shows an example of the cross-section of the thin portion 48. The cap 10 and the band portion 40 are integrally formed by resin molding. In the state immediately after molding, as shown by the broken line in FIG. 6(a), the flap 42 (a plurality of flaps 42 and a plurality of thin portions 48) protrudes outside the internal space formed by the cap 10 and the band portion 40. By bending the protruding flap 42 and thin portion 48 toward the internal space with a jig or the like, the above-described flap 42 and thin portion 48 are formed. At this time, in the flap 42, a base end portion 43 and an inclined portion 44 are formed. With the bending of the flap 42, a curved base end portion 43 is formed, and a restoring force (a restoring force that tends to fall toward the central axis Ax) that tries to return the flap 42 to its original state may occur.

[0061] The upper surface 43a of the base end portion 43 is curved so as to be concave downward. The radius of curvature of the upper surface 43a may be 0.75 mm or less, 0.72 mm or less, 0.70 mm or less, or 0.68 mm or less from the viewpoint of reducing the restoring force in the inclined portion 44. The radius of curvature of the upper surface 43a may be 0.55 mm or more, 0.57 mm or more, 0.60 mm or more, or 0.62 mm or more from the viewpoint of enabling the flap 42 to function. The radius of curvature of the upper surface 43a may be 0.55 mm to 0.75 mm.

[0062] Returning to FIG. 3, the stopper 4 includes a breaking portion 50. The breaking portion 50 connects the band main body 41 and the peripheral wall 14 of the cap 10 so that the band portion 40 and the cap 10 are separated when the cap 10 is removed from the spout 30. The breaking portion 50 has, for example, a plurality of ribs 52. The plurality of ribs 52 are provided on the inner peripheral surface of the band main body 41 and the inner peripheral surface of the base portion 28 of the peripheral wall 14, and project inward (toward the central axis Ax) from those inner peripheral surfaces (see also FIG. 4).

[0063] The plurality of ribs 52 are provided at predetermined intervals along the circumferential direction around the central axis Ax. For example, each of the plurality of ribs 52 is disposed between adjacent flaps 42 in the circumferential direction around the central axis Ax. Each of the plurality of ribs 52 is located above the thin portion 48. The thickness of the rib 52 (the amount of protrusion from the inner peripheral surface of the band main body 41) may be smaller than the amount of protrusion of the flap 42 from the inner peripheral surface of the band main body 41. A cut 54 extending to the inside (for example, substantially the center) of the rib 52 may be formed at the boundary between the lower end of the base portion 28 in the peripheral wall 14 of the cap 10 and the upper end of the band main body 41. The cap 10 and the band portion 40 are partitioned by the cut 54.

[0064] In one example, after the portion corresponding to the cap 10, the portion corresponding to the band portion 40, and the plurality of ribs 52 are integrally formed, at the height position that becomes the boundary between the cap 10 and the band portion 40, a cut 54 is formed that extends from the outside of the peripheral wall of the cap 10 to a position where the rib 52 is not divided. The cut 54 is continuously formed along the circumferential direction around the central axis Ax. By forming the cut 54, the cap 10 and the band portion 40 are formed, and the peripheral wall 14 (base portion 28) and the band main body 41 are in a state of being connected via the thin portion 56. The thin portion 56 is a portion of the rib 52 where the cut 54 is not formed at the height position of the cut 54.

[0065] The cut 54 is located above the upper end of the protruding portion 39a (side surface 37a) that forms the side surface 37a of the notch 38. The distance along the vertical direction between the cut 54 and the upper surface of the top plate 12 is smaller than the distance along the vertical direction between the upper end of the protruding portion 39a (side surface 37a facing the band main body 41) and the upper surface of the top plate 12. The distance between the lower end of the band main body 41 and the cut 54 (that is, the upper end of the band main body 41) may be 3.0 mm to 5.0 mm, or may be 3.5 mm to 4.5 mm. The thickness of the rib 52 may be 0.40 mm to 0.60 mm, or may be 0.45 mm to 0.55 mm.

[0066] When a user such as a consumer extracts the contents from the unopened packaging container 1, the cap 10 is rotated relative to the spout 30. Along with the relative rotation of the cap 10, the screwing engagement between the internal thread 15 formed on the peripheral wall 14 of the cap 10 and the external thread 33 formed on the side wall 32 of the spout 30 is gradually released. As the screwing engagement between the internal thread 15 and the external thread 33 is released, the cap 10 and the band portion 40 gradually separate from the flange 34 of the spout 30.

[0067] When the cap 10 and the band portion 40 begin to separate from the flange 34, soon a plurality of flaps 42 of the band portion 40 abut (hit) against the lower surface 38a of the notch 38 of the spout 30. When the flap 42 abuts against the notch 38, tensile stress is generated between the cap 10 and the band portion 40 (the thin portion 56 of the break portion 50), and the separation of the cap 10 and the band portion 40 from the flange 34 of the spout 30 is restricted. When the relative rotation of the cap 10 continues and the tensile stress reaches a predetermined value, the thin portion 56 breaks.

[0068] Each thin portion 56 of the plurality of ribs 52 is formed to have a strength such that it breaks when the tensile stress reaches a predetermined value. When all the thin portions 56 break, the cap 10 and the band portion 40 are physically separated (detached), and the restriction on the movement of the cap 10 is released. The band portion 40 separated from the cap 10 moves downward to a position where it contacts the ring portion 36 of the spout 30. After the cap 10 is removed from the spout 30, the band portion 40 remains on the spout 30.

[0069] (Method for manufacturing the stopper) Subsequently, an example of the method for manufacturing the stopper 4 will be described below. The method for manufacturing the stopper 4 includes at least a step of preparing the spout 30, a step of preparing the cap member, a step of screwing the internal thread 15 onto the external thread 33 to attach the cap member to the spout 30, and a step of forming the notch 54.

[0070] In the step of preparing the spout 30, for example, the spout 30 is manufactured by resin molding. In the step of preparing the cap member, a cap member in which a portion corresponding to the cap 10, a portion corresponding to the band portion 40, and a plurality of ribs 52 are integrated is manufactured, for example, by resin molding. The cap member has the same shape as the cap 10, the band portion 40, and the plurality of ribs 52, except that it does not have the thin-walled portion 56 (the cut 54 is not formed). Therefore, the cap member will be described below using the names of the constituent members of the cap 10 and the band portion 40. The peripheral wall of the cap member corresponds to the peripheral wall 14 of the cap 10 and the band main body 41 of the band portion 40 before they are separated from each other.

[0071] Immediately after resin molding, the plurality of flaps 42 and the plurality of thin-walled portions 48 protrude outside the internal space of the cap member. After resin molding, the plurality of flaps 42 and the plurality of thin-walled portions 48 in a connected state with each other are bent (folded) into the internal space of the cap member by a jig or the like. By bending with a jig or the like, a base end portion 43 and an inclined portion 44 are formed on the flap 42. The flap 42 is folded into the internal space of the cap member until the tip 42a of the flap 42 does not contact the inner peripheral surfaces of the spout 30 and the band main body 41.

[0072] Next, the upper end portion of the side wall 32 of the spout 30 is inserted inside the peripheral wall of the cap member. When the cap member is rotated in one direction around the central axis Ax with respect to the spout 30, the internal thread 15 of the peripheral wall 14 and the external thread 33 of the side wall 32 are screwed together, and the cap member moves in a direction approaching the flange 34 of the spout 30. Then, after the plurality of flaps 42 come into contact with the notch 38 (the inclined portion 39b), they begin to ride over the notch 38. Also, the upper end portion of the side wall 32 begins to be inserted between the peripheral wall 14 of the cap member and the inner ring 16.

[0073] When the cap member is further rotated relative to the spout 30, each flap 42 gets over the notch 38, and the upper end of the side wall 32 of the spout 30 is inserted between the peripheral wall of the cap member and the inner ring 16. As a result, the spout 30 is in a state capped by the cap member (a state where the cap member is attached to the spout 30).

[0074] Next, a step of forming a cut 54 (thin-walled portion 56) in the cap member is performed. For example, a cut is made around the entire circumference of the peripheral wall of the cap member using a score cutter to form the cut 54. In one example, the blade of the score cutter is applied from the outer periphery of the peripheral wall 14 to the portion that will later be the boundary between the base portion 28 and the band portion 40 of the peripheral wall 14 and the position corresponding to the portion that will be the boundary of each rib 70. In each of the plurality of ribs 52, the blade of the score cutter is inserted up to a substantially central portion in the lateral direction orthogonal to the central axis Ax of the rib 52.

[0075] Then, with the score cutter applied to the inside of the cap member and the ribs, the cap member and the spout 30 are rotated around the central axis Ax to form the cut 54. Thereby, the thin-walled portion 56 is formed in the rib 52. By forming the thin-walled portion 56, in the cap member, the cap 10 and the band portion 40 are separated, and these members are in a state connected via the rib 52 (thin-walled portion 56), and the mouthplug 4 is obtained. By adjusting the size of the cut 54 to change the size and thickness of the thin-walled portion 56, the force required for breaking can be adjusted. Thereafter, a step of attaching the mouthplug 4 to the container body 2 is performed, and the packaging container 1 is manufactured.

[0076] (Modification example) As shown in FIG. 7, the spout 30 may have a notch 38A instead of the notch 38. The notch 38A differs from the notch 38 in that it includes an inclined portion 39c in addition to the protruding portion 39a and the inclined portion 39b. The inclined portion 39c is a portion that forms an inclined surface 37c extending toward the side wall 32 in an inclined state from the lower surface of the protruding portion 39a. The inclined surface 37c of the inclined portion 39c may extend from the lower surface of the protruding portion 39a to the side wall 32. In the observation cross section including the central axis Ax, the point C where the inclined surface 37c of the inclined portion 39c intersects the lower surface of the protruding portion 39a is located inside the side surface 37a of the protruding portion 39a (point A located at the outermost side of the notch 38A).

[0077] The lower portion 32b of the side wall 32 is located below the lower end of the inclined portion 39c. In the observation cross section, when the boundary (the lower end of the inclined surface 37c) between the inclined portion 39c and the outer peripheral surface of the lower portion 32b is defined as point D, point D may be lower than the tip 42a of the flap 42. In this case, in the observation cross section, the shortest distance in the lateral direction orthogonal to the central axis Ax between the flap 42 (the tip 42a of the flap 42) and the spout 30 is defined by the shortest distance in the lateral direction between the tip 42a and the inclined portion 39c.

[0078] In the observation cross section, the lateral distance xc between the outer peripheral surface of the lower portion 32b and point C may be 55% or less, 50% or less, 45% or less, or 40% or less of the lateral distance xb between the outer peripheral surface of the lower portion 32b and point A from the viewpoint of enabling the flap 42 to function. The distance xc may be 0.6 mm or less, 0.55 mm or less, 0.50 mm or less, or 0.45 mm or less from the viewpoint of enabling the flap 42 to function.

[0079] In the observation cross-section, the corner near the side wall 32 of the tip 42a of the flap 42 may have a rounded shape. In the observation cross-section, the radius of curvature of the corner 44R formed by the tip 42a and the side surface 45 facing the central axis Ax of the flap 42 may be 0.30 mm or more, 0.32 mm or more, 0.34 mm or more, or 0.35 mm or more from the viewpoint of facilitating the sliding of the flap 42 when the flap 42 contacts the side wall 32 of the spout 30. In the observation cross-section, the radius of curvature of the corner 44R may be 0.6 mm or less.

[0080] The breaking portion 50 is not limited to the configuration in which the thin portion 56 is formed in the rib 52 as in the above example. When the cap 10 is removed from the spout 30, it may be formed in any manner as long as the cap 10 and the band body 41 are physically separated. The breaking portion 50 may include a breaking line. The breaking line includes a plurality of bridges connecting between the peripheral wall 14 of the cap 10 and the band body 41 at a plurality of locations around the central axis Ax. The plurality of bridges are formed to break when the tensile stress applied to themselves reaches a predetermined value. The breaking line may be formed by cutting the peripheral wall of the cap member with a cutter leaving a plurality of bridges.

[0081] [Advantages of the Embodiment]

[0082] By bending the flap 42, a restoring force may be generated in the flap 42 that tries to fall toward the spout 30. Due to the restoring force, the flap 42 may sandwich the spout 30, and when the cap 10 is removed, the band portion 40 may not fall downward. In the above-mentioned stopper 4, the flaps 42 adjacent to each other are connected by the thin portion 48. Therefore, even if any one of the flaps 42 tries to fall due to the restoring force toward the central axis Ax, the movement to fall is restricted. Therefore, the possibility that the flap 42 falls toward the central axis Ax and sandwiches the spout 30 can be reduced. Therefore, in the above-mentioned stopper 4, the separated band portion 40 can fall smoothly.

[0083] The ratio of the thickness Th1 of the plurality of flaps 42 to the thickness Th2 of the plurality of thin portions 48 may be 1.5 to 5.0. When the ratio is 1.5 or more, the processing of the flap 42 becomes easy. Also, when the ratio is 5.0 or less, it is possible to more reliably suppress the collapse due to the restoring force that may occur in the flap 42.

[0084] The thickness Th2 of the plurality of thin portions 48 may be 0.15 mm to 0.35 mm. The thickness Th1 of the plurality of flaps 42 may be 0.6 mm to 0.8 mm. When the thickness Th1 is 0.6 mm to 0.8 mm, when the thickness Th2 is 0.15 mm or more, it is possible to more reliably suppress the collapse due to the restoring force that may occur in the flap 42. When the thickness Th1 is 0.6 mm to 0.8 mm, when the thickness Th2 is 0.35 mm or less, the processing of the flap 42 is easy.

[0085] Each of the plurality of flaps 42 may be formed such that the width decreases from the tip toward the lower end of the band main body 41. In this case, when removing the cap 10, the bending process at the base of the flap 42 is easy while maintaining the range where the plurality of flaps 42 contact the notch 38.

[0086] The number of the plurality of flaps 42 may be 8 to 12. When the number of the plurality of flaps 42 is 8 or more, the flap 42 is caught by the notch 38, and a force for breaking the breaking portion is likely to be generated when removing the cap 10. Also, when the number of the plurality of flaps 42 is 12 or less, the bending process of the plurality of flaps 42 is easy.

[0087] The plurality of flaps 42 may be arranged so as to face the lower surface 38a of the notch 38 in a state separated from the spout 30. Since the flap 42 is arranged in a state separated from the spout 30, when the cap 10 is removed, it is difficult for the flap 42 to contact the spout 30. Therefore, the separated band portion 40 can fall more smoothly.

[0088] In a longitudinal cross-section (observation cross-section) including the central axis Ax of the cap 10, the distance d1 in the direction (lateral direction) orthogonal to the central axis Ax of the cap 10 between one flap 42 and the side wall 32 of the spout 30 may be 0.3 mm to 0.7 mm. By the distance d1 being 0.3 mm or more, the contact between the flap 42 and the spout 30 can be more reliably avoided. Also, by the distance d1 being 0.7 mm or less, the possibility that the tip of the flap 42 gets caught in the notch 38 when removing the cap 10 can be reduced, and the function of the flap 42 can be more reliably exhibited.

[0089] In the above observation cross-section, the distance d2 in the lateral direction of the cap 10 between the point A located at the outermost side of the notch 38 and the point B located at the innermost side of one flap 42 may be 0.5 mm to 0.9 mm. By the distance d2 being 0.5 mm or more, the possibility that the tip of the flap 42 gets caught in the notch 38 when removing the cap 10 can be reduced, and the function of the flap 42 can be more reliably exhibited. Also, by the distance d2 being 0.9 mm or less, the contact between the flap 42 and the spout 30 can be more reliably avoided.

[0090] In the above observation cross-section, the width wb along the lateral direction of the cap 10 of the portion of the side wall 32 located below the notch 38 may be 1.0 mm to 1.4 mm. By the width wb being 1.0 mm or more, the strength of the spout 30 can be maintained. By the width wb being 1.4 mm or less, the contact between the flap 42 and the spout 30 can be more reliably avoided.

[0091] In the above observation cross-section, the lateral distance xb between the lower portion 32b of the side wall 32 located below the notch 38 and the point A located at the outermost side of the notch 38 may be larger than the lateral distance xa between the upper portion 32a of the side wall 32 located above the notch 38 and the point A. In this case, the possibility of contact between the flap 42 and the spout 30 can be reduced.

[0092] The ratio of distance xb to distance xa may be 1.5 or more. By having the ratio be 1.5 or more, the possibility of contact between the flap 42 and the spout 30 can be further reduced.

[0093] Distance xb may be 1.0 mm to 1.4 mm. By having distance xb be 1.0 mm or more, the possibility of contact between the flap 42 and the spout 30 can be further reduced. Also, by having distance xb be 1.4 mm or less, the strength of the spout 30 can be maintained.

[0094] The notch 38 may include a protruding portion 39a that forms a side surface 37a extending along the central axis of the cap 10, and an inclined surface 37c that extends from the lower surface of the protruding portion 39a and is inclined with respect to the outer peripheral surface of the side wall 32. In this case, even if the flap 42 falls toward the spout 30 by the above-mentioned restoring force, the tip 42a of the flap 42 can come into contact with the inclined surface 37c. Due to the contact with the inclined surface 37c, the flap 42 becomes slippery, so that the band portion 40 can fall smoothly. Therefore, the possibility of the band portion 40 staying in its original position can be reduced.

[0095] Each of the plurality of flaps 42 may include a base end portion 43 connected to the lower end portion of the band main body 41 and formed to curve downward, and an inclined portion 44 connected to the base end portion 43 and formed to extend toward the top plate 12. In the above-mentioned observation cross-section, the radius of curvature of the upper surface 43a of the base end portion 43 may be 0.55 mm to 0.75 mm. By having the radius of curvature be 0.55 mm or more, the possibility that the tip 42a of the flap 42 gets caught in the notch 38 when removing the cap 10 can be reduced, and the function of the flap 42 can be more reliably exerted. By having the radius of curvature be 0.75 mm or less, the degree of deformation becomes large, and the restoring force generated in the inclined portion 44 can be reduced.

[0096] In the above observation cross-section, the minimum value of the inclination angles θ1 and θ2 of the side surface facing the central axis Ax of the cap 10 among the inclined portions 44 with respect to the lateral direction may be 50° or more. By the minimum value of the inclination angle being 50° or more, the possibility of contact between the flap 42 and the spout 30 can be reduced.

[0097] As described above, several embodiments have been explained, but the present disclosure is not limited to the above embodiments at all. Some matters described in one example may be applied to the stoppers of other examples.

Explanation of reference numerals

[0098] 1... Packaging container, 2... Container body, 4... Stopper, 10... Cap, 14... Peripheral wall, 15... Internal thread, 30... Spout, 32... Side wall, 33... External thread, 34... Flange, 38, 38A... Notch, 39a... Protruding portion, 39c... Inclined portion, 40... Band portion, 41... Band body, 42... Flap, 43... Base end portion, 44... Inclined portion, 45... Side surface, 48... Thin portion, 50... Breaking portion.

Claims

1. A spout having a cylindrical side wall, an external thread provided on the outer peripheral surface of the side wall, a flange provided on one end side of the side wall, and a notch formed so as to protrude outward from the side wall. A cap having a top plate, a peripheral wall connected to the outer peripheral edge of the top plate, and an internal thread provided on the inner peripheral surface of the peripheral wall and screwed with the external thread. A band portion having a cylindrical band body, a plurality of flaps that extend obliquely from the lower end portion of the band body toward the top plate and regulate the separation of the cap from the spout by abutting against the lower surface of the notch, and a plurality of thin portions having a thickness smaller than that of the plurality of flaps. A break portion that connects the band body and one end of the peripheral wall so that the band portion and the cap are separated when the cap is removed from the spout. A gap is provided between the lower end of the band portion and a portion of the flange that faces the lower end of the band portion. The plurality of flaps are arranged along the circumferential direction around the central axis of the cap. Each of the plurality of thin portions is a stopper that connects adjacent flaps among the plurality of flaps.

2. The stopper according to claim 1, wherein the ratio of the thickness of the plurality of flaps to the thickness of the plurality of thin portions is 1.5 to 5.

0.

3. The stopper according to claim 1 or 2, wherein the thickness of the plurality of thin portions is 0.15 mm to 0.35 mm, and the thickness of the plurality of flaps is 0.6 mm to 0.8 mm.

4. The stopper according to any one of claims 1 to 3, wherein each of the plurality of flaps is formed such that the width decreases from the tip toward the lower end portion of the band body.

5. The stopper according to any one of claims 1 to 4, wherein the number of the plurality of flaps is 8 to 12.

6. The stopper according to any one of claims 1 to 5, wherein the plurality of flaps are arranged to face the lower surface of the notch in a state of being separated from the spout.

7. The stopper according to any one of claims 1 to 6, wherein in a longitudinal section including the central axis, a distance d1 in a direction orthogonal to the central axis between one of the plurality of flaps and the side wall of the spout is 0.3 mm to 0.7 mm.

8. In a longitudinal section including the central axis, the distance d2 in the direction orthogonal to the central axis between point A located at the outermost side of the notch and point B located at the innermost side of one of the plurality of flaps is 0.5 mm to 0.9 mm. The stopper according to any one of claims 1 to 7.

9. In a longitudinal section including the central axis, the width wb along the direction orthogonal to the central axis of the portion of the side wall located below the notch is 1.0 mm to 1.4 mm. The stopper according to any one of claims 1 to 8.

10. In a longitudinal section including the central axis, the distance xb in the direction orthogonal to the central axis between the portion of the side wall located below the notch and point A located at the outermost side of the notch is greater than the distance xa in the direction orthogonal to the central axis between the portion of the side wall located above the notch and point A located at the outermost side of the notch. The stopper according to any one of claims 1 to 9.

11. The ratio of the distance xb to the distance xa is 1.5 or more. The stopper according to claim 10.

12. The distance xb is 1.0 mm to 1.4 mm. The stopper according to claim 10 or 11.

13. The notch includes a protruding portion forming a side surface extending along the central axis and an inclined surface extending obliquely from the lower surface of the protruding portion with respect to the outer peripheral surface of the side wall. The stopper according to any one of claims 1 to 12.

14. Each of the plurality of flaps includes a base end portion connected to the lower end portion of the band body and formed to curve downward, and an inclined portion connected to the base end portion and formed to extend toward the top plate. In a longitudinal section including the central axis, the radius of curvature of the upper surface of the base end portion is 0.55 mm to 0.75 mm. The stopper according to any one of claims 1 to 13.

15. Each of the plurality of flaps includes a base end portion connected to the lower end portion of the band body and formed to curve downward, and an inclined portion connected to the base end portion and formed to extend toward the top plate. In a longitudinal section including the central axis, the minimum value of the inclination angle of the side surface facing the central axis of the inclined portion with respect to the direction orthogonal to the central axis is 50° or more. The stopper according to any one of claims 1 to 13.

16. A stopper according to any one of claims 1 to 15, and a container body to which the stopper is attached. A packaging container comprising the same.

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