JP6310743B2 - Plastic container lid - Google Patents

Description

The present invention, on the inner peripheral surface of the tamper evident bottom portion directed to plastic container closure which locking projections are provided.

As beverage container, provided with a neck of cylindrical shape, this is the outer peripheral surface of the mouth-and-neck portion and an annular engaged ridge positioned below the male threaded with male screw thread is formed, Containers made of synthetic resin or glass are widely used in practice. As a container lid for such a container, as disclosed in Patent Documents 1 and 2 below, a circular top wall and a cylindrical skirt wall depending from the periphery of the top wall are provided, and the skirt A circumferentially breakable line extending in the circumferential direction is formed on the wall, and the skirt wall has a main portion above the circumferentially breakable line and a tamper evidence skirt below the circumferentially breakable line. A synthetic resin container lid in a form partitioned into two is proposed and put into practical use. A female thread is formed on the inner peripheral surface of the skirt wall, and a plurality of locking ridges extending in the circumferential direction or spaced in the circumferential direction on the inner peripheral surface of the tamper evidence skirt are continuous in the circumferential direction. An annular locking ridge extending in the direction is formed. The locking ridge has a lower surface whose radius gradually increases upward, a cylindrical outer peripheral surface, and a substantially horizontal upper surface. An annular fitting surface is disposed at a portion of the inner peripheral surface of the tamper evidence hem portion that follows the upper surface of the locking protrusion, and the inner diameter of the fitting surface is somewhat higher than the inner diameter of the portion above it. It is made small.

When sealing the mouth and neck by attaching the container lid to the mouth and neck of the container filled with the contents, put the container lid on the mouth and neck and close it (clockwise as viewed from above). Rotate and screw the female thread on the container lid onto the male thread on the mouth and neck. The container lid is gradually lowered with respect to the mouth and neck in accordance with the screwing of the female thread and the male thread, and the locking protrusion formed on the tamper evidence hem is formed on the mouth and neck. the engaged protrusions overcame elastically be brought located below. When opening the mouth and neck to consume the contents, the container lid is rotated in the opening direction (counterclockwise as viewed from above) to gradually release the threaded engagement of the female thread with the male thread. The part other than the tamper-evidence hem of the container lid is gradually raised with respect to the mouth and neck as the female thread is unscrewed from the male thread, but the tamper-evidence hem is formed on the inner peripheral surface. The raised locking ridge is locked to the locked ridge of the mouth-and-neck portion, so that the ascent is prevented, thereby breaking the circumferential breakable line, and the tamper evidence skirt is formed on the skirt wall. Separated from main part. Then, the tamper evidence hem is left in the mouth and neck, the portion other than the tamper evidence hem of the container lid is detached from the mouth and neck, and the mouth and neck are opened. In the time of the circumferential breakable line is broken, the engageable locking ridges tamper evident bottom portion also been slightly raised is formed on the tamper evident bottom portion is formed in the neck together it is caused to engage the locking protrusion, fitting surface that is arranged on the inner peripheral surface of the tamper evident bottom portion is brought resiliently engaged with the outer peripheral surface of the stopping projections of the neck The tamper evident hem is maintained in tension, which ensures that the circumferentially breakable line is sufficiently broken (in other words, the tamper evident skirt also rises without breaking the circumferential breakable line). Thus, the so-called slipping out of the mouth and neck is sufficiently reliably avoided).

JP 2011-143942 A Japanese Patent No. 5291175

Thus, according to the experience of the present inventors, it has been found that the conventional container lid as described above has the following problems to be solved. Tamper evident bottom portion in the circumferential direction breakable line is broken is also raised somewhat, the Kakaritome突mating surfaces neck disposed on the inner peripheral surface of the tamper evident bottom portion Even after the circumferentially breakable line is broken, due to the fact that the tamper evidence hem is maintained in a tensioned state elastically locked to the outer circumferential surface of the strip over the entire circumferential direction, The tamper-evidence hem is held in a raised position without being lowered, so that when the consumer holds the mouth and neck and consumes the contents, the tamper-edent hem is placed on the consumer's lips. It tends to abut and give consumers discomfort. In addition, when a portion other than the tamper evidence hem of the container lid is reattached to the mouth and neck, there is no sufficient gap between the lower end of the main part of the skirt wall and the upper end of the tamper evidence hem. Therefore, it is not clearly indicated that the circumferentially breakable line has already been broken, and the tamper evidence characteristics may be damaged.

The present invention has been made in view of the above-mentioned facts, and its main technical problem is to improve the container lid, and when opening the mouth and neck, the circumferentially breakable line is broken and the tamper evident hem is broken. When the part is separated from the main part of the skirt wall, the tamper evidence skirt is kept sufficiently lowered without being held in the raised position.

  As a result of diligent research and experiments, the present inventor has formed a plurality of protruding ribs on the inner peripheral surface of the tamper evidence hem at circumferential intervals, and each of the protruding ribs is connected to the inner surface of the tamper evidence hem. By arranging between adjacent locking ridges in the circumferential direction on the peripheral surface and in a radially outer portion of the upper surface of the locking ridge and / or following the upper surface of the locking ridge when viewed in the vertical direction. It has been found that the main technical problem can be achieved.

That is, according to the first aspect of the present invention, the synthetic resin container lid capable of achieving the main technical problem includes a circular top wall and a cylindrical skirt wall depending from the periphery of the top wall. The skirt wall is formed with a circumferentially breakable line extending in the circumferential direction, and the skirt wall has a main portion above the circumferentially breakable line and a lower part of the circumferentially breakable line. The tamper evident hem is divided into hems, female threads are formed on the inner circumferential surface of the main portion, and the inner circumferential surface of the tamper evidence hem is circumferentially spaced in the circumferential direction. A plurality of locking ridges extending are formed, and each of the locking ridges is a synthetic resin container lid having an upper surface that extends horizontally inward or inclined downward.
An annular inclined surface having an inverted frustoconical shape whose radius gradually increases downward is disposed on a portion of the inner peripheral surface of the tamper evidence skirt that follows the upper surface of the locking protrusion, and the inclined surface A plurality of projecting ribs are formed on the surface at intervals in the circumferential direction, and each of the projecting ribs is a lower end portion between adjacent locking projections when viewed in the circumferential direction on the inclined surface , and The protruding rib is disposed at a radially outer portion of the upper surface of the locking ridge and / or a portion following the upper surface of the locking ridge when viewed in the vertical direction, and the protruding rib has an inner surface extending in the axial direction. A synthetic resin container lid is provided.

Further, according to the second aspect of the present invention, a circular top wall and a cylindrical skirt wall depending from the peripheral edge of the top wall are provided, and a circumferentially breakable line extending in the circumferential direction is provided on the skirt wall. The skirt wall is partitioned into a main portion above the circumferentially breakable line and a tamper evidence skirt below the circumferentially breakable line, A female thread is formed on the circumferential surface, and a plurality of locking ridges extending in the circumferential direction are formed on the inner circumferential surface of the tamper evidence skirt at intervals in the circumferential direction. Each of the ridges is a synthetic resin container lid having an upper surface extending horizontally or inclining downward inward in the radial direction.
An annular inclined surface having an inverted frustoconical shape whose radius gradually increases downward is disposed on a portion of the inner peripheral surface of the tamper evidence skirt that follows the upper surface of the locking protrusion, and the inclined surface A plurality of projecting ribs are formed on the surface at intervals in the circumferential direction, and each of the projecting ribs is a lower end portion between adjacent locking projections when viewed in the circumferential direction on the inclined surface, and The protruding rib is disposed at a radially outer portion of the upper surface of the locking ridge and / or a portion following the upper surface of the locking ridge when viewed in the vertical direction, and the protruding rib has a linear inner edge extending in the axial direction. A synthetic resin container lid is provided.

In the synthetic resin container lid according to the first aspect and the second aspect of the present invention, the radius gradually decreases downward at the portion of the inner peripheral surface of the tamper evidence skirt that continues to the upper surface of the locking protrusion. An annular inclined surface with an increasing inverted frustoconical shape is arranged, the tamper evidence hem is raised slightly, and the locking ridge formed on the tamper evidence hem is formed on the mouth neck is allowed engaged with the engaged projection being, in the time of the circumferential breakable line is broken, the specific portion in the vertical direction of the inner circumferential surface of the tamper evident bottom portion is formed in the neck rather than resiliently engaged over the entire circumferential direction on the outer peripheral surface of the engaging ridges are, and vertically a lower end between adjacent engaging projections when viewed in the circumferential direction of the inclined plane A radially outer portion of the top surface of the locking ridge as viewed in the direction; and Or locking protruding ribs disposed on site following the upper surface of the ridge is locally resiliently brought engage the outer circumferential surface of the stopping projections formed on the neck, thus mouth neck adhesion of the tamper evident bottom portion with respect to the stopping projections formed on the parts are relatively small. Therefore, if the circumferentially breakable line is broken and the tamper evidence skirt is separated from the main part of the skirt wall, the tamper evidence skirt is lowered sufficiently without being held in the raised position. It is done.

The front view which shows a suitable embodiment of the synthetic resin container lid comprised according to the 1st aspect of this invention in part with a cross section. FIG. 2 is a development view of a tamper evidence skirt of the container lid shown in FIG. 1. The partial slope figure which shows the protrusion rib of the container lid shown in FIG. The fragmentary sectional view of the part in which the protrusion rib is formed which shows the state which mounted | wore the mouth neck part with the container lid shown in FIG. The fragmentary sectional view of the part in which the protrusion rib is not formed which shows the state which mounted | wore the mouth neck part with the container lid shown in FIG. In the second preferred embodiment of the plastic container closure constructed in accordance with aspects of the present invention, partial slant view illustrating a protruding Li blanking. Front view of a portion of a preferred embodiment of the container in cross-section. The fragmentary sectional view of the part in which the protrusion rib of the container is formed which shows the state which mounted | wore the container cover to the container shown in FIG. The fragmentary sectional view of the part in which the protrusion rib of the container is not formed which shows the state which mounted | wore the container shown in FIG. The partial slope figure which shows the modification of a protrusion rib.

  First, a preferred embodiment of a synthetic resin container lid constructed according to the first aspect of the present invention will be described in detail with reference to the accompanying drawings.

  Referring to FIG. 1, a container lid 2 that can be injection-molded or compression-molded from a suitable synthetic resin such as polyethylene or polypropylene includes a circular top wall 4 and a cylindrical skirt depending from the periphery of the top wall 4. Wall 6. A cylindrical inner seal piece 8 that hangs downward and a cylindrical outer seal piece 10 that also hangs downward are formed on the inner peripheral edge of the top wall 4. Further, a relatively small annular protrusion 12 is formed at the outer peripheral surface proximal end portion of the inner seal piece 8.

  The skirt wall 6 has a relatively thick thick upper portion 14 and a relatively thin thin thin portion 16. A breakable line 18 extending in the circumferential direction is formed at the upper end of the thin lower portion 16, and the skirt wall 6 has a main portion 20 above the breakable line 18 and a tamper evidence skirt 22 below the breakable line 18. It is divided into and. In the illustrated embodiment, the breakable line 18 includes a plurality of slits (grooves) 24 that extend in the circumferential direction at intervals in the circumferential direction, and a plurality of bridge portions 26 that remain between the slits 24. The tamper evidence skirt portion 22 is connected to the main portion 20 via a plurality of bridging portions 26.

On the outer peripheral surface of the main portion 20 of the skirt wall 6, anti-skid knurls 28 are formed which are formed of uneven shapes alternately present in the circumferential direction. A female thread 30 is formed on the inner peripheral surface of the main portion 20 of the skirt wall 6. A locking protrusion 32 is provided on the inner peripheral surface of the tamper evidence skirt 22. A plurality of locking protrusions 32 are arranged at intervals in the circumferential direction, and in the illustrated embodiment, five locking ridges 32 are arranged at equal angular intervals in the circumferential direction. Each main portion (portion excluding both end portions) of the locking protrusion 32 has a lower surface 34 whose radius gradually increases upward, a substantially arc-shaped outer peripheral surface 36, and a horizontally extending upper surface 38. The upper surface 38 may be inclined downward and extend inward in the radial direction .

2 and FIG. 3 together with FIG. 1, the radius gradually increases downward at a portion of the inner peripheral surface of the tamper evidence skirt 22 that continues to the upper surface of the locking protrusion 32. An annular inclined surface 40 having an inverted frustoconical shape is disposed (see FIG. 4). A plurality of protruding ribs 42 are formed on the inclined surface 40 at intervals in the circumferential direction, and each of the protruding ribs 42 is a lower end between adjacent locking protrusions 32 when viewed in the circumferential direction on the inclined surface 40. The protruding rib 42 extends in the axial direction and is disposed at a radially outer portion of the upper surface of the locking ridge and / or a portion following the upper surface of the locking ridge when viewed in the vertical direction. It is important to have an inner surface . In the illustrated embodiment, butt out rib 42, as will be clearly understood by reference to Figure 2, the locking projections 32 adjacent as viewed in the circumferential direction of the inner peripheral surface of the tamper evident bottom portion 22 One is arranged at the center in the circumferential direction between each of them. As clearly understood by referring to FIGS. 3 and 4, the protruding rib 42 has an inner surface 44 that extends in the axial direction, and preferably has a convex arc shape.

FIG. 1 also shows the mouth / neck portion 46 of the container together with the container lid 2. The mouth and neck portion 46 of the container which can be formed from an appropriate synthetic resin such as polyethylene terephthalate, glass or metal thin plate has a cylindrical shape as a whole, and a male thread 48 and a male thread are formed on the outer peripheral surface of the mouth and neck part 46. the stopping projections 50 are formed to be located below the 48. As will be understood by reference to FIGS. 4 and 5 in conjunction with FIG. 1, the stopping projections 50 are arcuate upper surface 52 having an outer diameter gradually increases downward, substantially vertically downwards following the upper surface 52 And a lower surface 56 extending substantially horizontally toward the inside in the radial direction. The boundary area between the outer peripheral surface 54 and the lower surface 56 forms a smooth curved surface. Disposed on the outer peripheral surface of the neck 46, further support ring 58 which is located below of the locking projections 50 (such support ring 58 to the person skilled in the art is used for the transport of containers as is well known) is also Has been.

When the container lid 2 is attached to the mouth / neck part 46 after filling the contents in the container and the mouth / neck part 46 is sealed, the container lid 2 is fitted on the mouth / neck part 46 and the container lid 2 is closed. 1, the female thread 30 of the container lid 2 is screwed to the male thread 48 of the mouth-and-neck portion 46. When the female thread 30 is screwed into the male thread 48 until the state shown in FIG. 1, the inner seal piece 8 of the container lid 2 enters the mouth neck part 46 and is brought into close contact with the inner peripheral surface of the mouth neck part 46. The annular protrusion 12 is brought into intimate contact with the top surface of the mouth and neck portion 46, and the outer seal piece 10 is brought into intimate or close proximity to the outer peripheral surface of the mouth and neck portion 46, thus sealing the mouth and neck portion 46. Stopping projections 32 disposed on the inner peripheral surface of the tamper evident bottom portion 22 to be locking projections 50 of the neck 46 is elastically (i.e. elastic deformation or displacement of the tamper evident bottom portion 22 by) overcome positioned below the stopping projections 50.

When opening the mouth-and-neck portion 46 to consume the contents, the container lid 2 is rotated in the opening direction, that is, counterclockwise as viewed from above in FIG. Thus, the screwing of the male thread 48 and the female thread 30 is gradually released, and the main portion 20 of the skirt wall 6 is moved upward in the axial direction along with the rotation. On the other hand, the tamper evident bottom portion 22 moving in the axial direction upwards is prevented because the engagement projection 32 is brought into engagement in the stopping projections 50 of the neck 46, thus bridges the fracture line 18 junction Stress is generated at 26, the bridging portion 26 is broken, and the tamper evidence skirt 22 is separated from the main portion 20 of the skirt wall 6. This time is slightly raised also tamper evident bottom portion 22 is in, but acts on the outer peripheral surface 54 of the annular inclined surface 40 is the stopping projections 50 in the initial stage of the tamper evident bottom portion 22 is raised Thus, the tamper evidence skirt 22 is gradually displaced outward in the radial direction, and when the tamper evidence skirt 22 is raised to the position shown in FIG. 4, the tamper evidence skirt 22 is disposed at intervals in the circumferential direction. only the inner surface 44 of the projecting rib 42 is brought into locally resiliently engaged with the outer peripheral surface of the engaging projections 50 formed on the neck 46. As will be appreciated by reference to Figure 5, in the region where the projecting ribs 42 are not present, a gap exists between the inner peripheral surface and the stopping projections 50 of the tamper evident bottom portion 22. Therefore, as compared with the case where the inner circumferential surface of the tamper evident bottom portion 22 is resiliently engaged with the outer peripheral surface over the entire circumferential direction of the locking projections 50 formed on the neck 46, adhesion of the tamper evident bottom portion 22 with respect to the stopping projections 50 formed on the mouth-neck portion 46 is small. Therefore, when the bridging portion 26 is broken and the tamper evidence skirt 22 is separated from the main portion 20 of the skirt wall 6, the tamper evidence skirt 22 is sufficiently held without being held in the raised position. To the position supported by the support ring 58. After the breakable line 18 is broken, the main portion 20 of the container lid 2 is freely moved upward in the axial direction along with the rotation and detached from the mouth and neck portion 46, and thus the mouth and neck portion 46 is opened.

FIG. 6 illustrates a preferred embodiment of a synthetic resin container lid constructed according to the second aspect of the present invention , wherein the protruding rib 42 has a linear inner edge 60 instead of an inner surface constructed from a curved surface. . The protruding rib 42 has a triangular cross-sectional shape and has a linear inner edge 60 extending in the axial direction. In the illustrated embodiment, the linear inner edge 60 is a straight line, but can be a curved line such as a convex arc if desired. In embodiments where the projecting ribs 42 have a linear inner edge 60 results in each of the projecting ribs 42 upon opening the neck 46 is locally linear or point contact with the stopping projections 50, the The adhesion force of the tamper evidence skirt 22 to the locking protrusion 50 is further reduced.

Next, a preferred embodiment of the container will be described in detail with reference to the accompanying drawings.

Figure 7 is a neck 146 of the container is shown. A mouth and neck portion 146 of a container that can be formed from an appropriate synthetic resin such as polyethylene terephthalate or glass has a cylindrical shape as a whole, and a male screw 148 and a male screw 148 on the outer peripheral surface of the mouth and neck portion 146. the stopping projections 150 are formed to be positioned below. The stopping projections 150 extending substantially horizontally toward the outer peripheral surface 154 and a radially inwardly extending substantially vertically downwardly following the arcuate top surface 152, top surface 152 having an outer diameter gradually increases downward It has a lower surface 156. Disposed on the outer peripheral surface of the neck 146, further, the support ring 158 located below of the stopping projections 150 (according support ring 158 to one skilled in the art is used for the transport of containers as is well known) is also Has been.

The lower portion of the outer peripheral surface of the stopping projections 150 at intervals in the circumferential direction that are formed a plurality of projecting ribs 162. In the illustrated embodiment, the protruding rib 162 is formed on the lower end of the outer peripheral surface 154 of the locking protrusion 150. As clearly understood by referring to FIG. 8 in conjunction with FIG. 7, the protruding rib 162 has an outer surface 164 that extends in the axial direction, and preferably has a convex arc shape.

  After filling the contents in the container, the container lid 102 is attached to the mouth and neck portion 146, and the mouth and neck portion 146 is sealed. The container lid 102 attached to the mouth-and-neck portion 146 may be different from the container lid 2 shown in FIG. 1 only in that the protruding rib 42 is not formed (in FIGS. 8 and 9, The number corresponding to each part of the container lid 2 shown in FIG. 1 is given by adding 100 to the number given to each part of the container 2). When the container lid 102 is attached to the mouth-and-neck portion 146, the container lid 102 is fitted on the mouth-and-neck portion 146, the container lid 102 is rotated in the closing rotation direction, and the female thread 130 of the container lid 102 is moved to the mouth-and-neck. The male thread 148 of the part 146 is screwed together.

When opening the mouth and neck 146 to consume the contents, the container lid 102 is rotated in the opening direction. As a result, the male screw 148 and the female screw 130 are gradually disengaged, and the main portion 120 of the skirt wall 106 is moved upward in the axial direction along with the rotation. On the other hand, the tamper evident bottom portion 122 moves in the axial direction upwards is prevented because the locking protrusions 132 is brought into engagement in the stopping projections 150 of the neck 146, thus bridges the fracture line 118 junction Stress is generated at 126, the bridging portion 126 is broken, and the tamper evidence skirt 122 is separated from the main portion 120 of the skirt wall 106. This time is slightly raised also tamper evident bottom portion 122 is in. In the initial stage of the tamper evident bottom portion 122 is raised annular inclined surface 140 is applied to the outer circumferential surface of the stopping projections 150 that When the tamper evidence skirt 122 is gradually displaced outward in the radial direction, and when the tamper evidence skirt 122 is raised to the position shown in FIG. 8, the circumferentially spaced protrusions are provided. Only the outer surface 164 of the rib 162 is locally elastically locked. Shiku monkey understood by reference to Figure 9, in the region where the protruding rib 162 is not present, a gap exists between the inner peripheral surface and the stopping projections 150 of the tamper evident bottom portion 122. Therefore, as compared with the case where the inner circumferential surface of the tamper evident bottom portion 122 is resiliently engaged with the outer peripheral surface over the entire circumferential direction of the stopping projections 150 are formed on the neck 146, adhesion of the tamper evident bottom portion 122 with respect to the stopping projections 150 are formed on the neck 146 is small. Therefore, when the bridging portion 126 is broken and the tamper evidence skirt 122 is separated from the main portion 120 of the skirt wall 106, the tamper evidence skirt 122 is sufficiently held without being held in the raised position. To a position supported by the support ring 158. After the breakable line 118 is broken, the main portion 120 of the container lid 102 is freely moved upward in the axial direction along with the rotation and detached from the mouth and neck portion 146, and thus the mouth and neck portion 146 is opened.

FIG. 10 illustrates a modified example of the protruding rib 162. The protruding rib 162 shown in FIG. 10 has a linear outer edge 166 extending in the axial direction rather than an outer surface extending in the axial direction. If desired, the outer edge 166 can be curved, such as a convex arc. Will be the inner circumferential surface of the tamper evident bottom portion 122 is a line or point contact with the outer edge 166 of protruding ribs 162 upon opening the neck 146 in the case of the protruding ribs 162 shown in FIG. 10, the locking The adhesion force of the tamper evidence skirt 122 to the ridge 150 is further reduced.

2, 102: Container lid 4, 104: Top wall 6, 106: Skirt wall 18, 118: Breakable line 22, 122: Tamper evidence hem 26, 126: Bridge 32, 132: Locking ridge
38: Upper surface
42: protruding rib
44: inner surface of 46,146: the mouth-and-neck portion 50, 150: the locking projections
60: Inner edge 162: Protruding rib 164: Outer surface 166: Outer edge

Claims (2)

A circular top wall and a cylindrical skirt wall depending from the periphery of the top wall, the skirt wall is formed with a circumferential breakable line extending in the circumferential direction, and the skirt wall is in the circumferential direction A main portion above the breakable line and a tamper evidence bottom below the circumferential breakable line are partitioned, and an internal thread is formed on the inner peripheral surface of the main portion, and the tamper A plurality of locking ridges extending in the circumferential direction are formed on the inner peripheral surface of the evidence skirt, and each of the locking ridges is horizontally directed radially inward. Or a synthetic resin container lid having an upper surface extending obliquely downward,
An annular inclined surface having an inverted frustoconical shape whose radius gradually increases downward is disposed on a portion of the inner peripheral surface of the tamper evidence skirt that follows the upper surface of the locking protrusion, and the inclined surface A plurality of projecting ribs are formed on the surface at intervals in the circumferential direction, and each of the projecting ribs is a lower end portion between adjacent locking projections when viewed in the circumferential direction on the inclined surface , and The protruding rib is disposed at a radially outer portion of the upper surface of the locking ridge and / or a portion following the upper surface of the locking ridge when viewed in the vertical direction, and the protruding rib has an inner surface extending in the axial direction. A synthetic resin container lid. A circular top wall and a cylindrical skirt wall depending from the periphery of the top wall, the skirt wall is formed with a circumferential breakable line extending in the circumferential direction, and the skirt wall is in the circumferential direction A main portion above the breakable line and a tamper evidence bottom below the circumferential breakable line are partitioned, and an internal thread is formed on the inner peripheral surface of the main portion, and the tamper A plurality of locking ridges extending in the circumferential direction are formed on the inner peripheral surface of the evidence skirt, and each of the locking ridges is horizontally directed radially inward. Or a synthetic resin container lid having an upper surface extending obliquely downward,
An annular inclined surface having an inverted frustoconical shape whose radius gradually increases downward is disposed on a portion of the inner peripheral surface of the tamper evidence skirt that follows the upper surface of the locking protrusion, and the inclined surface A plurality of projecting ribs are formed on the surface at intervals in the circumferential direction, and each of the projecting ribs is a lower end portion between adjacent locking projections when viewed in the circumferential direction on the inclined surface , and The protruding rib is disposed at a radially outer portion of the upper surface of the locking ridge and / or a portion following the upper surface of the locking ridge when viewed in the vertical direction, and the protruding rib has a linear inner edge extending in the axial direction. to which the synthetic resin container closure, characterized in that.