JP6091420B2 - Resin cap and method for manufacturing the same - Google Patents

Description

  The present invention relates to a resin cap that is mounted to seal a container that contains a beverage or the like, and a method for manufacturing the same.

  2. Description of the Related Art As a resin cap that is attached to a container that contains a beverage or the like, one having a tamper evidence performance that can confirm the presence or absence of unauthorized opening is widely used. If the customer can confirm that the beverage has not been opened before purchasing the beverage, etc., damage caused by mischief can be prevented and the quality of the contents is guaranteed. For example, a cap body composed of a disk-shaped top plate and a side wall portion extending from the edge of the top plate, and a bulging portion of the container mouth portion connected to the opening end of the cap body via a plurality of breakable bridges There is known a resin cap provided with a tamper-evidence band having a locking portion for locking to the inside.

  In the resin cap, the locking portion is locked to the bulging portion of the container mouth portion by the opening operation from the mounted state, and the plurality of bridges are broken by a tensile force acting on the plurality of bridges. The cap body and the tamper evidence band are separated from each other. Thereby, when it is confirmed that the bridge is broken, it is recognized that the bridge is opened.

  In general, even if the opening force is applied to the bridge and the tensile force begins to act on the bridge, the resin bridge does not break immediately, and it stretches with the rotation of the cap body until the rising amount of the cap body exceeds a predetermined amount. Go. On the other hand, since interest in quality has been increasing more recently, further improvement in tamper evidence performance is desired, and a characteristic that can quickly break the bridge when the opening operation starts is required. Yes. For example, Patent Document 1 describes a resin cap in which the bridge is ruptured quickly by making the circumferential dimension of the bridge larger than usual and reducing the number thereof.

JP 2010-76797 A

  From the aspect of quality assurance, the bridges of the resin cap are required to have a certain strength as well as being easily broken. In this respect, the number of bridges of the resin cap described in Patent Document 1 is significantly smaller than the conventional one, and the force acting on each bridge is very large. Therefore, although the radial dimension of each bridge is increased, there is a possibility that sufficient strength cannot be obtained with respect to the acting force.

  Accordingly, an object of the present invention is to provide a resin cap capable of quickly breaking a plurality of bridges while maintaining sufficient strength, and a method for manufacturing the same, in view of the above-described problems of the prior art.

In order to achieve the above object, the following technical measures were taken.
The present invention comprises a cap body attached to the container mouth portion, and a tamper evidence band connected to the open end of the cap body via a plurality of breakable bridges, and the opening operation from the attached state is performed by the opening operation. A resin cap in which a plurality of bridges are broken and the cap body and the tamper evidence band are separated from each other, and is directed radially inward from an outer wall surface at a boundary between the cap body and the tamper evidence band. The cap body and the tamper-evidence band are separated from each other by the slits that are inserted, and the plurality of bridges are formed by connecting portions that do not include the slits in the boundary portions. In the cap made of steel, the circumferential dimension of the connecting portion of each of the plurality of bridges Is a 0.65～1.10Mm, and each of the plurality of bridges have the usual bridge and the intensity of substantially equal circumferential dimension is less than 0.55mm of a linking moiety, the circumferential dimension of the connecting portion Is a [mm], and the radial dimension of the connecting portion is b [mm], the relationship of 0.10 <a × b <0.18 is satisfied.

  According to the resin cap of the present invention, the circumferential dimension of each connecting portion of the plurality of bridges is 0.65 to 1.10 mm, and each of the plurality of bridges has substantially the same strength as a normal bridge. Therefore, the radial dimension of the connecting portion is small, and a plurality of bridges can be quickly broken when a plug opening operation is performed. Since each of the plurality of bridges has substantially the same strength as a normal bridge, and it is not necessary to significantly reduce the number of the plurality of bridges, it is sufficient for the force acting on each bridge. The strength can be maintained.

  When the circumferential dimension of the connecting part is a [mm] and the radial dimension of the connecting part is b [mm], when the relationship of 0.10 <a × b <0.18 is satisfied, When the circumferential dimension a [mm] is in the range of 0.65 to 1.10 mm, sufficient strength of each of the plurality of bridges can be maintained.

  The plurality of bridges that connect the cap body and the tamper evidence band can be configured in various forms, for example, a plurality of cross-sections that cross between the cap body and the tamper evidence band between them. The inner rib of a shape is formed, and what is formed by making the remaining allowance which put the said slit in the said some inner rib into the said connection part is mentioned. In the above-described prior art in which the bridge is formed by a plurality of inner ribs and the number of the bridges is greatly reduced, the circumferential dimension between adjacent bridges is greatly widened, so that a force is applied when grasping and turning the resin cap. The cap body twists depending on the condition. For this reason, it is difficult to always perform quick breakage of a plurality of bridges stably. In the present invention, it is not necessary to significantly reduce the number of the plurality of bridges, and the distance between adjacent bridges does not increase greatly, so that twisting of the cap body when gripping and turning the resin cap can be reduced. . Therefore, even when the bridge is formed by the plurality of inner ribs, the plurality of bridges can always be promptly broken stably.

The present invention comprises a cap body attached to the container mouth portion, and a tamper evidence band connected to the open end of the cap body via a plurality of breakable bridges, and the opening operation from the attached state is performed by the opening operation. A resin cap in which a plurality of bridges are broken and the cap body and the tamper evidence band are separated from each other, and is directed radially inward from an outer wall surface at a boundary between the cap body and the tamper evidence band. The cap body and the tamper-evidence band are separated from each other by the slits that are inserted, and the plurality of bridges are formed by connecting portions that do not include the slits in the boundary portions. in manufacturing the cap, the plurality of bridges, the circumferential dimension of the connecting portion 0.5 a first bridge circumferential dimension of the plurality of 0.65~1.10mm said connecting portion and having a normal bridge and intensity substantially equal is mm or less, the circumferential dimension of the connecting portion is less 0.55mm A plurality of second bridges that are normal bridges of the first bridge, the circumferential dimension of the connecting portion of each of the first bridges is a [mm], and the radial dimension of the connecting portion is b [mm]. In this case, the relationship of 0.10 <a × b <0.18 is satisfied.

  According to the resin cap of the present invention, the circumferential dimension of each connecting portion of the plurality of first bridges is 0.65 to 1.10 mm, and each of the plurality of first bridges is substantially equivalent to a normal bridge. Therefore, when the opening operation is performed, the plurality of first bridges are quickly broken. be able to. After the plurality of first bridges are broken, almost all of the force can be applied to the plurality of second bridges. As a result, the first and second bridges can be quickly broken. Since each of the plurality of first bridges has substantially the same strength as a normal bridge, and it is not necessary to reduce the number of first and second bridges, the force acting on each bridge is not affected. And sufficient strength can be maintained.

  When the circumferential dimension of the connecting portion of each of the plurality of first bridges is a [mm] and the radial dimension of the connecting portion is b [mm], 0.10 <a × b <0.18. When the relationship is satisfied, the sufficient strength of each of the plurality of first bridges is maintained when the circumferential dimension a [mm] of each of the connection portions of the plurality of first bridges is in the range of 0.65 to 1.10 mm. It becomes possible to do.

  The plurality of first bridges and the plurality of second bridges may be arranged in any manner, for example, each of the plurality of first bridges and each of the plurality of second bridges or two or more first bridges. Examples include one bridge group and two or more second bridge groups that are alternately arranged.

  The plurality of bridges that connect the cap body and the tamper evidence band can be configured in various forms, for example, a plurality of cross-sections that cross between the cap body and the tamper evidence band between them. The inner rib of a shape is formed, and what is formed by making the remaining allowance which put the said slit in the said some inner rib into the said connection part is mentioned. In the above-described prior art in which the bridge is formed by a plurality of inner ribs and the number of the bridges is greatly reduced, the circumferential dimension between adjacent bridges is greatly widened, so that a force is applied when grasping and turning the resin cap. The cap body twists depending on the condition. For this reason, it is difficult to always perform quick breakage of a plurality of bridges stably. In the present invention, it is not necessary to significantly reduce the number of the plurality of bridges, and the distance between adjacent bridges does not increase greatly, so that twisting of the cap body when gripping and turning the resin cap can be reduced. . Therefore, even when the bridge is formed by the plurality of inner ribs, the plurality of bridges can always be promptly broken stably.

  As described above, according to the present invention, since the radial dimension of each connecting portion of the plurality of bridges is small, the plurality of bridges can be quickly broken when the opening operation is performed. Each of the plurality of bridges has substantially the same strength as a normal bridge, and since it is not necessary to significantly reduce the number of the plurality of bridges, sufficient strength is provided for the force acting on each bridge. Can be maintained.

It is sectional drawing in the state which mounted | wore the container mouth part with the resin cap which concerns on 1st Embodiment of this invention, and the part left with a broken line is a partial side view of a resin cap. It is sectional drawing of a resin cap. It is the expansion perspective view which looked at the some bridge | bridging and its periphery from the inner side. It is an AA line expanded sectional view of Drawing 2 which is a portion in which a slit was formed. It is a figure corresponding to the sectional view on the AA line of FIG. 2 of the resin cap which concerns on 2nd Embodiment of this invention. (A) And (b) is a figure corresponding to the sectional view on the AA line of FIG. 2 of the resin-made caps concerning 3rd and 4th embodiment of this invention. (A) And (b) is a figure corresponding to the AA sectional view taken on the line of FIG. 2 of the resin caps according to the fifth and sixth embodiments of the present invention. It is sectional drawing of the resin caps which show other embodiment. It is a chart showing the relationship between the load and the displacement in the tensile test of the resin caps of Examples and Comparative Examples.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the resin cap 1 according to the first embodiment of the present invention attached to the mouth portion (container mouth portion) 51 of the container 50, and FIG. 2 is a cross-sectional view of the resin cap 1. . In the following description, the direction corresponding to the top and bottom of FIG. The resin cap 1 is used by being attached to the mouth 51 of a container 50 such as a plastic bottle made of synthetic resin. The resin cap 1 is integrally formed of polypropylene by compression molding or injection molding, and includes a cap body 2 located at the upper part and a tamper evidence band 3 connected to the lower end of the cap body 2. . The material for forming the resin cap 1 is not particularly limited, and polyethylene, polylactic acid, and the like are suitably used in addition to the polypropylene used in the present embodiment.

  The mouth portion 51 for mounting the resin cap 1 includes a cylindrical main body 52 formed with substantially the same diameter from the upper end to the lower end, a male screw 53 formed on the outer peripheral side of the main body portion 52, and the male screw 53. A bulging portion 54 having a diameter expanded on the lower side and a support ring 55 having a diameter larger than that of the bulging portion 54 on the lower side of the bulging portion 54 are provided.

  The cap body 2 is constituted by a top plate 4 positioned at the uppermost part and a side wall portion 5 extending downward from an outer edge 4a of the top plate 4, and the top plate 4 is a disc-like shape having required dimensions. A packing 20 for sealing the container 50 is provided inside the top plate 4. The packing 20 includes a disc-like plate-like portion 21 along the lower surface 4 b of the top plate 4, an annular side seal 22 that bends downward from the outer peripheral portion 21 a of the plate-like portion 21, and a lower surface from the lower surface 21 b of the plate-like portion 21. It has a cylindrical middle leg 23 extending toward it. The side seal 22 enters between the upper end portion 51 a of the mouth portion 51 and the side wall portion 5 of the cap body 2, and the middle foot 23 is in close contact with the inner surface n of the upper end portion 51 a of the mouth portion 51. The multiple sealing structure by these seals the mouth part 51 satisfactorily, so that the airtightness inside the container 50 is kept high.

  The side wall portion 5 of the cap body 2 is formed in a cylindrical shape having a required dimension, and a female screw 6 that is screwed into the male screw 53 of the mouth portion 51 is formed on the inner peripheral side thereof. As shown in FIG. 2, the female screw 6 is composed of a plurality of projecting portions 6A provided continuously at a predetermined interval in the circumferential direction, and allows liquid material to pass through in the vertical direction. A knurled groove 7 extending in the vertical direction is formed on the outer peripheral side of the side wall portion 5.

  As shown in FIG. 2, a plurality of bridges 8 are formed at predetermined intervals in the circumferential direction at the boundary between the side wall 5 and the tamper evidence band 3. Each of these bridges 8 connects the cap body 2 and the tamper evidence band 3 to each other, and breaks when pulled by a predetermined force. The tamper evidence band 3 is formed in a cylindrical shape whose diameter is slightly increased as it goes downward. On the inner side of the tamper evidence band 3, locking portions 9 that extend obliquely upward inward from the lower end portion 3 a of the tamper evidence band 3 are formed at regular intervals.

  The locking portion 9 has a substantially rectangular shape in plan view, and can be elastically deformed radially inward and radially outward. The locking portion 9 is positioned immediately below the bulging portion 54 in a state of being attached to the mouth portion 51, and is locked to the bulging portion 54 by a plugging operation.

  FIG. 3 is an enlarged perspective view of the plurality of bridges 8 and the periphery thereof viewed from the inside. A process of forming the resin cap 1 will be described. First, using a molding machine, a molded product in which the cap body 2 and the tamper evidence band 3 are integrally molded, and a plurality of inner ribs 12 having a substantially rectangular cross section extending between them are formed at the boundary portions thereof. obtain. By adjusting the mold, the circumferential dimension of the plurality of inner ribs 12 formed in the molded product is 0.65 to 1.10 mm, and the radial dimension is, for example, about 0.6 mm. Thereafter, the slit 10 is formed by the slit blade 60 so as to enter the radially inner side from the outer wall surface 3g of the portion corresponding to the plurality of inner ribs 12, and the cap body 2 and the tamper evidence band 3 are separated from each other. At the same time, a plurality of bridges 8 are formed by inserting slits 10 in the plurality of inner ribs 12 and using the remaining allowance 10 a as a connecting portion 11 between the cap body 2 and the tamper evidence band 3.

FIG. 4 is an enlarged cross-sectional view taken along line AA of FIG. 2 where the slit 10 is formed. As shown in the figure, the remaining allowance 10 a of the slit 10 that has entered the inner rib 12 formed in the above process becomes the connecting portion 11 of each bridge 8. The connecting portion 11 has a substantially rectangular shape when viewed from the side, and its circumferential dimension a is preferably 0.65 to 1.10 mm, and more preferably 0.80 mm to 0.95 mm. When the circumferential dimension a of the connecting portion 11 is 0.80 mm to 0.95 mm, the circumferential dimension of the inner rib 12 to be formed is set to 0.80 mm to 0.95 mm. Whereas the circumferential dimension of the connecting portion of the normal bridge is 0.55 mm or less, the connecting portion 11 of the resin cap 1 of the present embodiment is slightly wider in the circumferential direction than usual. The connecting portion 11 of each bridge 8 has a cross-sectional dimension that satisfies the following relational expression when the circumferential dimension is a [mm] and the radial dimension is b [mm].
0.10 <a × b <0.18

  When the circumferential dimension a of the connecting portion 11 is 0.65 mm to 1.10 mm and the circumferential dimension a and the radial dimension b satisfy the above relational expression, the strength of 9.0 kgf to 16.0 kgf is maintained. ing. Here, the strength refers to the strength that is not converted into a unit area when the bridge is pulled and broken. This strength is substantially equal to the strength of a normal bridge having a circumferential dimension of the connecting portion of 0.55 mm or less. In order to maintain such strength, the circumferential dimension a of the connecting portion 11 is The radial dimension b is adjusted with the change, and the radial dimension b is set to 0.10 mm to 0.30 mm. The radial dimension b is smaller than usual, that is, the connecting portion 11 of each bridge 8 in the present embodiment is laterally longer than usual and thinner in the radial direction. In a normal resin cap, the degree of penetration into the inner rib of the slit is about 50%, and the remaining allowance is a connecting portion of each bridge, whereas in the resin cap 1 of the present embodiment, The slit 10 is inserted deeper to about 55% to 90% of the inner rib 12, and the remaining allowance 10 a is a connecting portion 11 of each bridge 8.

  The circumferential dimension a of the connecting portion 11 is set to 0.65 mm to 1.10 mm. If the circumferential dimension a is smaller than 0.65 mm, the radial dimension b is set to maintain a predetermined range of strength. This is because the effect of adjusting the cross-sectional dimension of the connecting portion 11 is difficult to be obtained because it becomes too large, and if it exceeds 1.10 mm, the radial dimension b of the connecting portion 11 becomes too small and difficult to manufacture. The value obtained by multiplying the circumferential dimension a and the radial dimension b (area S: mm2) in the above relational expression varies depending on the target strength. For example, when the strength is 10 kgf, S = 0.10 S = 0.13 to 0.14 is preferable when the strength is 12 kgf to 13 kgf, and S = 0.17 to 0.18 is preferable when the strength is 13 kgf to 15 kgf. Is preferred.

  The function of each part when the resin cap 1 is attached to the mouth part 51 and the cap body 2 is separated from the tamper evidence band 3 by the opening operation will be described. When the resin cap 1 is turned in the closing direction, the resin cap 1 is depressed by the screws 6 and 53, and the engaging portion 9 is elastically deformed from the lower side to the upper side. However, it gets over the male screw 53 and the bulging portion 54 of the mouth portion 51. The locking portion 9 elastically returns to its original shape when it has passed over the bulging portion 54 and is fitted to the lower side of the bulging portion 54 to complete the mounting of the resin cap 1.

  When the resin cap 1 is turned in the opening direction and begins to rise upward, the locking portion 9 is locked to the bulging portion 54. Therefore, the tamper evidence band 3 cannot go upward any more, and a tensile force starts to act on the plurality of bridges 8. When the resin cap 1 is further rotated, the plurality of bridges 8 are further pulled as the cap body 2 is raised. And when the cap main body 2 raises only the required amount, the some bridge | bridging 8 is pulled largely and leads to a fracture | rupture. Thereby, the cap main body 2 is separated from the tamper evidence band 3, and the opening operation is completed.

  In the present embodiment, the slit 10 is inserted deeper into the wide inner rib 12 in the molding process, and the radial dimension b of the connecting portion 11 is smaller than usual. That is, the connecting portion 11 of each bridge 8 of the resin cap 1 is longer in the circumferential direction than usual and thinner in the radial direction as described above. Therefore, when a tensile force is applied to the plurality of bridges 8 by the opening operation, the plurality of bridges 8 can be quickly broken. Further, each of the plurality of bridges 8 has substantially the same strength as a normal bridge, and at the same time, it is not necessary to significantly reduce the number of the plurality of bridges 8. Sufficient strength against force can be maintained. Furthermore, since it is not necessary to significantly reduce the number of the plurality of bridges 8 and the distance between the adjacent bridges 8 does not increase greatly, the twist of the cap body 2 when the resin cap 1 is grasped and rotated can be reduced. it can. Thereby, the quick fracture | rupture of the some bridge | bridging 8 can always be performed stably.

  FIG. 5 is a view corresponding to the cross-sectional view taken along line AA of FIG. 2 of the resin cap 40 according to the second embodiment of the present invention. This embodiment differs from the above embodiment in that a bridge is formed without providing inner ribs. In the case of forming the resin cap 40, after obtaining a molded product in which the cap body and the tamper evidence band 41 are integrally molded, a slit blade (not shown) provided with irregularities in the radial direction is used to radially inward the outer wall surface 41g. The cap 42 and the tamper evidence band 41 are separated from each other. At the same time, a plurality of bridges 44 are formed by using the remaining portion 42 a with the slits 42 as a connecting portion 43 between the cap body and the tamper evidence band 41.

  Also in the present embodiment, the connecting portion 43 of each bridge 44 has a relation of 0.10 <a × b <0.18 when the circumferential dimension is a [mm] and the radial dimension is b [mm]. The relationship is satisfied, and the plurality of bridges 44 are quickly broken by the opening operation as in the first embodiment. Further, each of the plurality of bridges 44 has substantially the same strength as a normal bridge, and at the same time, it is not necessary to significantly reduce the number of the plurality of bridges 44. Sufficient strength against force can be maintained.

  6A and 6B are views corresponding to the cross-sectional view taken along the line AA of FIG. 2 of the resin caps 17 and 18 according to the third and fourth embodiments of the present invention, respectively. These embodiments are different from the first embodiment in that normal bridges are mixed. Both the plurality of bridges in FIG. 1A and the plurality of bridges in FIG. 2B have substantially the same strength as a normal bridge, and the circumferential dimension a of the connecting portion 11 is 0.65 to 1.10 mm. The plurality of first bridges 15 and the plurality of second bridges 71 that are normal bridges having a circumferential dimension c of the connecting portion 70 of 0.55 mm or less are configured.

  In the embodiment of FIG. 6 (a), each of the plurality of first bridges 15 and each of the plurality of second bridges 71 are arranged alternately, and in the embodiment of FIG. 6 (b), two first bridges are provided. The first bridge group 15A composed of 15 and 15 and the second bridge group 71A composed of two second bridges 71 and 71 are alternately arranged. A broken line 19 in the figure indicates a tip position where a slit blade enters when the slit 10 is formed.

  In the embodiment of FIG. 6B, the first bridge group 15A and the second bridge group 71A are both configured by two bridges, but the first and second bridges 15, 15A and 71A constituting the bridge groups 15A and 71A, 71 may be increased. The first bridge 15 and the second bridge 71, or the first bridge group 15A and the second bridge group 71A may be arranged irregularly instead of being alternately arranged. Also in these embodiments, when the circumferential dimension of the connecting portion 11 of each first bridge 15 is a [mm] and the radial dimension of the connecting portion is b [mm], 0.10 <a × b < The relationship of 0.18 is satisfied, and the plurality of first bridges 15 are quickly broken by the opening operation as in the first embodiment.

  After the plurality of first bridges 15 are broken, almost all of the force can be applied to the plurality of second bridges 71. As a result, the plurality of first and second bridges 15, 71 can be quickly broken. Can do. Since each first bridge 15 has substantially the same strength as each second bridge 71 which is a normal bridge, it is not necessary to reduce the number of the first and second bridges 15 and 71, respectively. Sufficient strength can be maintained with respect to the force acting on the bridges 15 and 71. It is not necessary to reduce the number of the first and second bridges 15 and 71 and the distance between adjacent bridges does not increase, so that the twist of the cap body 2 when the resin caps 17 and 18 are gripped and rotated is reduced. Can do. Thereby, the quick fracture | rupture of the some 1st, 2nd bridge | bridgings 15 and 71 can always be performed stably.

  FIGS. 7A and 7B are views corresponding to the cross-sectional view taken along the line AA of FIG. 2 of the resin caps 37 and 38 according to the fifth and sixth embodiments of the present invention. These embodiments are different from the first embodiment in that a bridge is formed without providing an inner rib and a normal bridge is mixed. Both the plurality of bridges in FIG. 1A and the plurality of bridges in FIG. 2B have substantially the same strength as a normal bridge, and the circumferential dimension a of the connecting portion 43 is 0.65 to 1.10 mm. A plurality of first bridges 16 and a plurality of second bridges 72 which are normal bridges having a circumferential dimension c of the connecting portion 73 of 0.55 mm or less.

  In the embodiment of FIG. 7A, each of the plurality of first bridges 16 and each of the plurality of second bridges 72 are arranged alternately, and in the embodiment of FIG. The first bridge group 16A composed of the bridges 16 and 16 and the second bridge group 72A composed of the two second bridges 72 and 72 are alternately arranged.

  In the embodiment of FIG. 7B, the first bridge group 16A and the second bridge group 72A are both configured by two bridges, but the first and second bridges 16 constituting the bridge groups 16A and 72A, 72 may be increased. The first bridge 16 and the second bridge 72, or the first bridge group 16A and the second bridge group 72A may be arranged irregularly instead of alternately. Also in these embodiments, when the circumferential dimension of the connecting portion 43 of each first bridge 16 is a [mm] and the radial dimension of the connecting portion 43 is b [mm], 0.10 <a × b The relationship <0.18 is satisfied, and the plurality of first bridges 16 are quickly broken by the opening operation.

  After the plurality of first bridges 16 are broken, almost all of the force can be applied to the plurality of second bridges 72. As a result, the plurality of first and second bridges 16, 72 can be quickly broken. Can do. Since each first bridge 16 has substantially the same strength as a normal bridge, and it is not necessary to reduce the number of the first and second bridges 16 and 72, it acts on each bridge 16 and 72. It is possible to maintain sufficient strength against the force to be applied.

  The resin caps of the embodiments disclosed above exemplify the resin caps according to the present invention, and the shape, dimensions, constituent resin, molding method and the like of each part are appropriately changed. For example, it is of course possible to apply to the one-piece cap shown in FIG. 8 that does not have a separate packing. In the resin cap 30 of FIG. 8, an annular middle leg 32 that is in close contact with the inner peripheral surface of the mouth portion of the container on the top plate 31, an annular rib 33 that is in contact with the upper end surface of the mouth portion, and an outer peripheral surface of the mouth portion. The outer legs 34 that are in close contact with each other are formed integrally, and the multiple seal structure formed by these seals the mouth of the container satisfactorily so that the airtightness inside the container is maintained high. .

  The number of bridges may be increased or decreased, or the arrangement of bridges may be changed. For example, a plurality of bridges may be arranged irregularly instead of at regular intervals. The shape of each bridge is not limited to a square cross section, but may be a triangular cross section, another polygonal cross section, or a circular cross section. In these cases, the degree of penetration of the slit is adjusted according to each shape so that the required strength can be maintained, and the circumferential dimension and the radial dimension of the connecting portion are determined. You may make it the cross-sectional shape of the connection part of a some bridge | bridging mutually differ. For example, forming the 2 or more types of bridge | bridging from which either the circumferential direction dimension and radial direction dimension of a connection part, or the circumferential direction dimension and radial direction dimension differ is mentioned. The container to which the resin cap of the present invention is applied is not limited, and the shape of the mouth is not limited.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. Ten resin caps of Examples 1 to 7 and Comparative Example each having different circumferential dimensions and radial dimensions of the connecting portion of the bridge were manufactured, and a strength test and a bridge fracture test were performed. In the strength test, a tensile / compression tester is used and the tensile speed is 50 mm / min. In the bridge fracture test, the container is filled with warm water or room temperature water and sealed with a resin cap, and then the resin cap is 1 rpm. The number of bridge breaks at the time of leakage was counted, and the ratio of the broken bridge to the total number of bridges was determined. Ten average values were obtained for both the strength test and the bridge break test.

  In Example 1, the circumferential dimension of the connecting portion of the bridge is 0.70 mm, the radial dimension is 0.19 mm, in Example 2, the circumferential dimension is 0.80 mm, and the radial dimension is 0.13 mm. Directional dimension 0.80mm, radial dimension 0.18mm, Example 4 circumferential dimension 0.80mm, radial dimension 0.22mm, Example 5 circumferential dimension 0.95mm, radial dimension Is 0.14 mm, the circumferential dimension is 0.95 mm as Example 6, the radial dimension is 0.18 mm, and the circumferential dimension is 1.10 mm and the radial dimension is 0.11 mm as Example 7. As a comparative example, a resin cap having a circumferential dimension of the connecting portion of the bridge of 0.55 mm and a radial dimension of 0.30 mm was manufactured.

  Table 1 shows the results of the strength test and the bridge break test of Examples 1 to 7 and the comparative example. In Examples 1 to 7, the ratio of the number of fractures of the bridge exceeds 70%, whereas in the comparative example, the ratio of the number of fractures of the bridge is 46%. In the resin caps of Examples 1 to 7 in which the radial dimension of the connecting portion is small, it is recognized that almost all the bridges are broken at the time of leakage or immediately after that.

  Resin caps of Example 3 (circumferential dimension: 0.80 mm), Example 5 (circumferential dimension: 0.95 mm), and Example 7 (circumferential dimension: 1.10 mm), and comparative example (circumferential dimension) FIG. 9 shows a chart showing the relationship between the load and the displacement in the tensile test of the resin cap having a directional dimension of 0.55 mm. Each chart is an average value of 10 in each example and comparative example. The distance from the peak position at which the maximum load value is reached to the fracture position is indicated by Rmm. That is, this distance is an index of the ease with which the bridge breaks. Table 2 shows R values and break angles of the resin caps of Example 3, Example 5, and Example 7 and the resin cap of the comparative example. In the resin caps of the examples and comparative examples, the cap body is lifted by 3.18 mm by turning 360 °, and the breaking angle is a line in which the line connecting the peak position and the breaking position is directed in the circumferential direction. The angle made with respect to.

  From Table 2, the break angle of the resin cap of each example is 30 to 70% of the break angle of the resin cap of the comparative example, and the bridge of the resin cap of each example breaks at a smaller rotation angle than before. Is allowed to do.

DESCRIPTION OF SYMBOLS 1 Resin cap 2 Cap main body 3, 41 Tamper evidence band 8, 44 Bridge 9 Locking part 10, 42 Slit 10a, 42a Remaining allowance 11, 43, 70, 73 Connection part 15, 16 First bridge 20 Packing 51 Mouth part 52 Main Body 54 Swelling 60 Slit Blade 71, 72 Second Bridge

Claims (7)

A cap body attached to the container mouth, and a tamper evidence band connected to the open end of the cap body via a plurality of breakable bridges. A resin cap that is broken and the cap body and the tamper evidence band are separated from each other,
The cap body and the tamper evidence band are separated from each other by a slit that enters radially inward from the outer wall surface of the portion that becomes the boundary between the cap body and the tamper evidence band. In the resin cap in which the plurality of bridges are formed by a connecting part that does not include the slit in the part to be,
The connecting portion of each of the plurality of bridges has a circumferential dimension of 0.65 to 1.10 mm, and each of the plurality of bridges includes a normal bridge having a connecting portion having a circumferential dimension of 0.55 mm or less. When the circumferential dimension of the connecting part is a [mm] and the radial dimension of the connecting part is b [mm], 0.10 <a × b <0.18. A resin cap characterized by satisfying the relationship.   2. The resin cap according to claim 1, wherein the connecting portion is formed on a plurality of inner ribs having a substantially rectangular cross section across a portion that becomes a boundary between the cap body and the tamper evidence band. . A cap body attached to the container mouth, and a tamper evidence band connected to the open end of the cap body via a plurality of breakable bridges. A resin cap that is broken and the cap body and the tamper evidence band are separated from each other,
The cap body and the tamper evidence band are separated from each other by a slit that enters radially inward from the outer wall surface of the portion that becomes the boundary between the cap body and the tamper evidence band. In the resin cap in which the plurality of bridges are formed by a connecting part that does not include the slit in the part to be,
Wherein the plurality of bridges, the first circumferential dimension circumferential dimension of the connecting portion and having a normal bridge and intensity substantially equal or less 0.55mm of multiple 0.65~1.10mm connecting portion The bridge includes a plurality of second bridges that are normal bridges having a circumferential dimension of 0.55 mm or less, and the circumferential dimension of the coupling part of each of the plurality of first bridges is a [ mm], and satisfying the relationship of 0.10 <a × b <0.18, where b [mm] is the radial dimension of the connecting portion.   Each of the plurality of first bridges and each of the plurality of second bridges, or a first bridge group consisting of two or more first bridges and a second bridge group consisting of two or more second bridges are staggered. The resin cap according to claim 3, wherein the resin cap is disposed on the surface. 5. The resin according to claim 3, wherein the connecting portion is formed on a plurality of inner ribs having a substantially rectangular cross section across a portion that becomes a boundary between the cap body and the tamper evidence band. Made of cap. It is a manufacturing method of the resin cap for manufacturing the resin cap as described in any one of Claims 1-5,
After obtaining a molded product in which the cap body and the tamper evidence band are integrally molded, a slit is made from the outer wall surface at the boundary between the cap body and the tamper evidence band toward the inside in the radial direction. And the tamper-evidence band are separated from each other, and the remaining caps with the slits are used as connecting portions to form the plurality of bridges. A plurality of substantially square inner ribs extending between the cap main body and the tamper evidence band are formed at a boundary portion between the cap main body and the tamper evidence band, and the remaining portion obtained by inserting the slits into the plurality of inner ribs is connected to the connecting portion. The method of manufacturing a resin cap according to claim 6, wherein the plurality of bridges are formed.

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