JP2006151405A - Container lid composed of sheet metal shell and synthetic resin packing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a container lid (2) which does not require an excessive unsealing torque, allows a circumferential breaking line (12) to be broken certainly before unsealing a mouth-to-neck part (46), and has a sufficient impact resistance and appropriate blow-off characteristics. <P>SOLUTION: For the container lid (2), a synthetic resin packing (6) is employed, which is molded separately from a shell (4) and capable of moving freely, instead of employing a synthetic resin liner embossed and fixed on the inner surface of a top wall (8) of the shell (4). The packing (6) has an annular outside seal ring (36) hanging from lower surface of the peripheral edge of the packing (6), an annular additional hanging part (40) hunging from the lower surface of the annular outside seal ring, and an annular flange (42) on the outside of the outside seal ring. The outside seal ring, the additional hanging part, and the flange have respective specific forms. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a container lid composed of a thin metal plate shell having a top wall and a skirt wall depending from the peripheral edge of the top wall, and a synthetic resin packing having a generally disk shape inserted into the shell. About.

  As is well known, as a container for beverages such as coffee, a metal thin plate container having a curl formed at the upper end and a male thread and a locking jaw on the outer peripheral surface has been widely used recently. It is used for practical use. As a container lid suitable for such a metal thin plate container, a container lid composed of a metal thin plate shell and a synthetic resin liner has been proposed as disclosed in Patent Documents 1 and 2 below. The shell has a top wall and a skirt wall depending from the peripheral edge of the top wall, and the skirt wall has a circumferential break line extending in the circumferential direction, and the skirt wall is above the circumferential break line. And a tamper-evidence skirt below the circumferential break line. A plurality of ventilation holes are formed in the upper part of the main part of the skirt wall at intervals in the circumferential direction. Each of the vent holes is formed by forming a lateral slit extending substantially horizontally and forcing the lower portion of the slit radially inward to generate an inward displacement portion. A synthetic resin liner is formed by supplying a soft or molten synthetic resin material to the inner surface of the top wall of the shell, and stamping the synthetic resin material into a required shape, and is fixed to the inner surface of the shell's top wall. ing.

When sealing the mouth and neck by attaching a container lid to the mouth and neck of the container, the container lid is fitted on the mouth and neck and pressed downward, and usually the top wall of the shell and the skirt wall And the liner is brought into intimate contact with the mouth and neck. While maintaining such a state, a female thread is formed in the main part of the shell corresponding to the male thread of the mouth and neck, and the lower part of the tamper evidence hem is deformed radially inward to form the mouth and neck. Lock to the locking jaw of the part. When opening the mouth and neck, rotate the container in the opening direction. Thus, since the female thread of the shell is moved along the male thread of the mouth and neck, the container lid is raised with the rotation. However, the tamper evident hem is prevented from rising because the lower part is locked to the locking jaw of the mouth and neck, and therefore considerable stress is generated in the circumferential break line, and the circumferential break line breaks. As a result, the tamper evidence hem is separated from the main part of the skirt wall. After that, the tamper evidence hem is left in the mouth and neck, the container lid is raised with rotation, is detached from the mouth and neck, and the mouth and neck are opened. If an axial break line is formed at the tamper evidence hem, a portion of the circumferential break line is maintained without breaking, the axial break line is broken, and the tamper evidence skirt is The container lid is developed from an endless annular shape to an end-band shape, and the entire container lid including the tamper evidence skirt is detached from the mouth and neck.
JP 2001-139053 A JP 2003-175862 A

  Therefore, in the case of a container lid applied to various types of containers as well as the above-described metal sheet containers, the necessary opening torque that must be applied to the container lid when opening the mouth and neck of the container is excessive. It is important that women and children can easily open and that the circumferential break line is broken sufficiently and the tamper-evidence characteristics are ensured sufficiently before the mouth and neck are unsealed. is there. Furthermore, it has sufficient impact resistance, that is, it maintains the sealing of the mouth and neck without damaging the container lid even if the container with the container lid is dropped in an inverted state and a considerable impact is applied to the container lid. And having so-called blow-off characteristics, that is, if the pressure in the container increases excessively, for example, due to excessive heating of the container contents, the sealing is released, the internal pressure is released, and the container bursts. Alternatively, it is important that flight of the container lid is avoided. However, according to the experience of the present inventors, the above-described conventional container lid cannot always satisfy these requirements.

  The present invention has been made in view of the above facts, and the main technical problem thereof is that the necessary opening torque does not become excessive, and the circumferential break line is sufficiently ensured before the opening of the neck and neck is released. It is intended to provide a container lid that is particularly suitable for, but not limited to, a sheet metal container, having sufficient impact resistance and suitable blow-off characteristics.

  As a result of earnest research, the present inventors have replaced the synthetic resin liner that is embossed on the inner surface of the top surface wall of the shell and fixed to the inner surface of the top surface wall. Adopting a synthetic resin packing that can move freely, an annular outer seal ring that hangs from the lower surface of the peripheral edge, an annular additional hanging portion that hangs further from the lower surface of the annular outer seal ring, and the outside of the outer seal ring It has been found that the main technical problem can be achieved by making the outer seal ring, the additional drooping portion and the flange each have a specific shape by having the annular flange located at the position.

That is, according to the present invention, the container lid that achieves the main technical problem described above is composed of a thin metal shell and a synthetic resin packing, and the shell is a top wall and a skirt wall that hangs down from the periphery of the top wall. The skirt wall is formed with a circumferential break line extending in the circumferential direction, and the skirt wall is a main portion above the circumferential break line and below the circumferential break line. And a plurality of ventilation holes are provided at an upper portion of the main part at intervals in the circumferential direction, and each of the ventilation holes extends substantially horizontally. In the container lid formed by forming a lateral slit and forcing the lower part of the lateral slit radially inward to generate an inward displacement part,
The packing comprises a main wall portion that is generally disc-shaped, an annular outer seal ring that hangs from the lower surface of the peripheral edge of the outer main wall portion, an additional suspending portion that further hangs from the lower surface of the outer seal ring, and an outer seal ring Having an annular flange located on the outside;
The inner peripheral surface of the outer seal ring is radially outwardly directed downward at an inclination angle α of 20 to 40 degrees with respect to the central axis of the container lid before the container lid is attached to the mouth / neck portion of the container. It is in the shape of a truncated cone that tilts in the direction, and when the container lid is attached to the mouth and neck of the container, it is brought into close contact with the upper outer peripheral surface of the mouth and neck,
The inner peripheral surface of the additional drooping portion is displaced radially outward with respect to the inner peripheral surface of the outer seal ring, and even when the container lid is attached to the mouth and neck of the container, The outer peripheral surface of the additional drooping portion is located immediately inside the inward displacement portion of the shell in a radial direction without being intimately contacted;
The bottom surface of the flange is positioned opposite to the upper end edge of the inward displacement portion of the shell with a distance D1 of 0.3 to 3.5 mm in a state where the container lid is attached to the mouth and neck of the container. To
A container lid is provided.

  Preferably, the radial distance D2 between the outer peripheral edge of the lower surface of the flange of the packing and the minimum inner peripheral edge of the upper edge of the inward displacement portion of the shell is 0 when the container lid is attached to the mouth and neck of the container. .1 to 1.0 mm. When the container lid is attached to the mouth and neck of the container, the outer peripheral surface of the additional hanging portion of the packing has an inverted truncated cone shape that is inclined radially inward downward, and the additional hanging portion in the radial direction. It is preferable that the upper end of the outer peripheral surface of the shell is substantially aligned with the minimum inner peripheral edge of the upper end edge of the inner displacement portion of the shell. An annular ridge is formed on the upper surface of the peripheral edge of the packing, and the annular ridge is advantageously brought into contact with the inner surface of the top wall of the shell. Preferably, an annular inner ring is also formed on the lower surface of the packing so as to hang radially inward from the outer seal ring, and the inner side of the container with the container lid attached to the mouth and neck of the container. The ring is inserted into the mouth and neck of the container. When attached to the mouth and neck of the container, the boundary between the top wall and the skirt wall of the shell is expediently immersed downward and radially inward.

  In the container lid of the present invention, since the shell and the packing are relatively movable, when the circumferential break line of the shell is broken in order to open the mouth and neck of the container, the shell and packing are in close contact with each other. It is not necessary to rotate the packing that has been squeezed, it is sufficient to rotate only the shell, and therefore the initial required rotational torque at the time of opening can be made sufficiently small. Since the upper edge of the inner displacement portion of the shell faces the lower surface of the gasket flange with a gap D1 of 0.3 to 3.5 mm when mounted on the mouth and neck of the container, the circumferential direction of the shell After the break line is broken and the main portion of the top wall and the skirt wall of the shell rises by a predetermined distance D1, the upper edge of the inner displacement portion of the shell comes into contact with the lower surface of the flange of the packing, and thus the top wall and the skirt of the shell As the main part of the wall is raised, the packing is raised, so that after the circumferential breaking line of the shell is broken, the packing is raised so that it is separated from the mouth and neck and the sealing of the mouth and neck is released. It is reliably prevented that the peripheral edge portion of the packing is excessively bent and the flange moves below the inner displacement portion of the shell by the additional hanging portion coming into contact with the inner peripheral surface of the inner displacement portion. In addition, as clearly understood from Examples and Comparative Examples described later, it has appropriate blow-off characteristics with sufficient impact resistance.

  Hereinafter, a preferred embodiment of a container lid constructed according to the present invention will be described in more detail with reference to the accompanying drawings.

  Referring to FIG. 1 illustrating a preferred embodiment of a container lid constructed in accordance with the present invention, the container lid, generally designated by the numeral 2, is formed from a suitable metal sheet such as an aluminum-based alloy sheet. The shell 4 and the shell 4 are separately composed of an appropriate synthetic resin, for example, a packing 6 formed of a blend resin of styrene elastomer and polypropylene.

  The shell 4 has a circular top wall 8 and a skirt wall 10 that is generally cylindrical and hangs down from the periphery of the top wall 8. The central part of the top wall 8 is immersed in the peripheral part. More specifically, the top wall 8 has an annular peripheral edge portion 8a extending substantially horizontally, an intermediate portion 8b having an inverted frustoconical shape, and a central immersion portion 8c that is substantially horizontal. A circumferential break line 12 is formed in the lower part of the skirt wall 10 of the shell 4, and the skirt wall 10 has a main portion 14 above the circumferential break line 12 and a tamper evidence below the circumferential break line 12. It is partitioned into a skirt 16. In the illustrated embodiment, an annular bulging portion 18 is formed at the lower part of the skirt wall 10, and the annular bulging portion 18 is spaced between the slit 20 extending in the circumferential direction and spaced between the slit 20. The circumferential direction fracture line 12 comprised from the bridge part 22 which exists in this is arrange | positioned. An annular groove portion 24 is formed in the main portion 14 of the skirt wall 10. A plurality of vent holes 26 are disposed above the annular groove portion 24 at intervals in the circumferential direction. As clearly understood by referring to FIG. 2 in conjunction with FIG. 1, each of the vent holes 26 forms a transverse slit 28 extending in a circumferential direction and extending substantially horizontally and below the transverse slit 28. It is formed by forcing the portion radially inward to generate the inward displacement portion 30.

  When the description is continued with reference to FIG. 2 together with FIG. 1, the packing 6 has a main wall portion 32 having a disk shape as a whole. The main wall portion 32 includes a peripheral edge portion 32a extending substantially horizontally, an inverted frustoconical intermediate portion 32b, and an immersion central portion 32c that is substantially horizontal. An annular protrusion 34 is formed on the upper surface of the peripheral edge portion 32 a of the main wall portion 32.

  On the lower surface of the peripheral surface portion 32a of the main wall portion 32, two annular rings, that is, an annular outer seal ring 36 and an annular inner ring 38 are formed. The inner peripheral surface 36a of the outer seal ring 36 has a frustoconical shape that is inclined radially outwardly at an inclination angle α with respect to the central axis of the container lid 2, and the inclination angle α is 20 to 40 degrees. , Preferably 25 to 35 degrees. The inner ring 38, which is located radially inwardly with respect to the outer seal ring 36, is suspended longer than the outer seal ring 36, extends substantially vertically and then tilts somewhat radially inward toward the bottom. Thus, the outer peripheral surface extends substantially vertically, the inner peripheral surface extends substantially vertically, and the lower surface is relatively narrow. The lower end portion of the outer peripheral surface and the outer peripheral edge portion of the lower surface are connected by a smooth curved surface. When viewed in the radial direction, the annular protrusion 34 disposed on the upper surface of the main wall portion 32 is located between the outer seal ring 36 and the inner ring 38.

  It is important that the outer seal ring 36 is provided with an additional drooping portion 40 that hangs further downward from its lower surface and an annular flange 42 that is located radially outward. Conveniently, the additional drooping portion 40 has an annular shape extending continuously in the circumferential direction. The inner peripheral surface 40 a of the additional drooping portion 40 is displaced radially outward with respect to the inner peripheral surface 36 a of the outer seal ring 36, and the lower end of the inner peripheral surface 36 a of the outer seal ring 36 and the additional drooping portion 40. A downwardly facing annular shoulder surface 44 extending substantially horizontally is formed between the upper end of the inner peripheral surface 40a. The radial width of the annular shoulder surface 44 is preferably about 0.1 to 0.5 mm. The inner peripheral surface 40a of the additional drooping portion 40 may also have a truncated cone shape that inclines downward in the radial direction. It is preferable that the outer peripheral surface 40b of the additional drooping portion 40 has a cylindrical shape extending substantially vertically or an inverted frustoconical shape inclined somewhat inward in the radial direction downward. The lower surface 40c of the additional drooping portion 40 may be an annular plane that extends substantially horizontally. The flange 42 attached to the outside of the outer seal ring 36 has a lower surface 42c that is an annular flat surface extending substantially horizontally. In the illustrated embodiment, the lower surface 42c of the flange 42 is positioned substantially in the same plane as the lower surface of the outer seal ring 36 (ie, the annular shoulder surface 44). The flange 42 also has an outer peripheral surface 42b having a substantially vertical cylindrical shape and an upper surface 42d having a substantially truncated cone shape. An upper surface 42 d of the flange 42 forms an extended surface of the upper surface of the main wall portion 32. Such a packing 6 is inserted into the shell 4, and as understood by referring to FIG. 2, the flange 42 of the packing 6 is elastically deformed so that the upper edge of the inward displacement portion 30 in the shell 4 is deformed. It is allowed to pass.

  FIG. 3 also shows the mouth / neck portion 46 of the container to which the container lid 2 is applied together with the container lid 2 described above. The mouth and neck portion 46 of the container, which can be formed of a chromic acid-treated steel sheet, an aluminum-based alloy sheet, or a tin sheet, has a substantially cylindrical shape as a whole, and a male thread 48 is formed at the center in the axial direction. A locking jaw 50 having an annular bulging shape is formed below the male screw 48. The upper part of the mouth / neck part 46 is formed into a truncated cone shape whose diameter gradually decreases upward, and an outer curl 52 is formed at the upper end of the mouth / neck part 46. The curl 52 extends upward in the cross-sectional view, extends in an arc shape upward and radially outward, extends in an arc shape downward and radially outward, extends downward, and downwards and radially inward. It extends in a circular arc shape and further extends in a circular arc shape upward and radially inward. Since the metal container itself provided with such a mouth-and-neck part 46 is well known, detailed description of the metal container itself is omitted in this specification.

  An example of the mounting operation for mounting the container lid 2 on the container's mouth / neck 46 and sealing the mouth / neck 46 will be described as follows. When the contents to be filled in the container are coffee, normally, after filling the container with coffee, nitrogen gas is introduced into the container to remove the air in the upper space of the container from the container. At the same time, water vapor is introduced into the container, and then the container lid 2 is fitted onto the mouth and neck portion 46. When the water vapor is liquefied due to the temperature drop, the inside of the container fitted with the container lid 2 is decompressed, and the container lid 2, particularly its packing 6, is sucked by the decompression, and as shown in FIG. The inner seal ring 38 is advanced into the mouth-and-neck portion 46, and thus the mouth-and-neck portion 46 is temporarily sealed. In such a state, the packing 6 is raised relative to the shell 4, and the annular protrusion 34 formed on the upper surface of the peripheral edge portion 32 a of the main wall portion 32 of the packing 6 (see also FIG. 2). Is brought into contact with the inner surface of the peripheral edge 8 a of the top wall 8 of the shell 4.

  Next, as shown in FIG. 4, the pressing tool 54 having a flat annular lower surface is pressed against the top wall 8 of the shell 4, and the pressing tool 56 having a shoulder 58 facing downward is connected to the top wall 8 and the skirt wall 10. Acting on the boundary between the two and immersing the boundary downward and radially inward. In this way, as clearly shown in FIG. 5, the annular protrusion 34 formed on the upper surface of the peripheral edge portion 32 a of the main wall portion 32 of the packing 6 is brought into close contact with the inner surface of the peripheral edge portion 8 a of the top wall 8 of the shell 4. Further, the inner peripheral surface 36a of the outer annular seal ring 36 of the packing 6 is brought into close contact with the upper portion of the outer peripheral surface of the outer curl 52 of the mouth / neck portion 46 to seal the mouth / neck portion 46. The inner peripheral surface 40a of the additional hanging portion 40 of the packing 8 is spaced apart from the outer peripheral surface of the outer curl 52 of the mouth / neck portion 46 without being in close contact. Further, the thread forming tool 60 is applied to the skirt wall 10 of the shell 4 to form the female thread 62 along the male thread 48 of the mouth-and-neck section 46 downward from the annular groove 24 (FIG. 1). . Further, a locking tool 64 is applied to the lower part of the tamper evidence skirt 16 of the skirt wall 10 to force the lower part of the tamper evidence skirt 16 radially inward to lock the jaws of the mouth and neck 46. Lock to 50. The construction of the pressing tools 54 and 56, the thread forming tool 60 and the locking tool 64, and also the capping by them may be in a form well known to those skilled in the art, so a detailed description thereof will be given here. Omitted.

  The description will be continued with reference to FIG. 4 and FIG. 5. In the state where the container lid 2 is attached to the mouth / neck portion 46 of the container as required as described above, It is important that a gap D1 of 0.3 to 3.5 mm exists between the upper edge of the lateral displacement portion 30 and the lower surface of the flange 42 of the packing 6. The radial distance D2 between the outer peripheral edge of the lower surface 42c of the flange 42 of the packing 6 and the minimum inner peripheral edge of the upper end edge of the inner displacement portion 30 of the shell 4 is preferably 0.1 to 1.0 mm. is there. Further, the outer peripheral surface 40b of the additional drooping portion 40 of the packing 6 has an inverted conical shape inclined inward in the radial direction downward, and the upper end of the outer peripheral surface 40b of the additional drooping portion 40 and the inner displacement portion 30 in the radial direction. It is preferable that the upper end circle is substantially aligned with the minimum inner peripheral edge of the upper end circle.

  When the content filled in the container is coffee, the container lid 2 is usually attached to the neck and neck portion 46 as described above, and then the container is heated to, for example, about 130 ° C. to be sterilized. Cool with good cooling water. The cooling water sprayed into the container enters the shell 4 through the air holes 26 formed in the skirt wall 10 of the shell 4, but the upper surface of the packing 6, particularly the annular ridge 34 is the inner surface of the top wall 8 of the shell 4. Therefore, the cooling water is reliably prevented from entering between the immersive central portion 8c of the top wall 8 of the shell 4 and the immersive central portion 32c of the packing 6.

  When the contents of the mouth and neck 46 of the container are opened and the contents are consumed, the shell 4 of the container lid 2 is rotated in the opening direction, that is, counterclockwise as viewed from above in FIG. Thus, the shell 4 is raised along with the rotation by the cooperation of the male thread 48 of the mouth and neck portion 46 and the female thread 62 of the shell 4. However, the tamper-evidence skirt 16 of the shell 4 is locked to the locking jaw 50 of the mouth-neck 46 and is therefore prevented from rising, whereby the circumferential direction formed on the skirt wall 10 of the shell 4 A considerable stress is generated at the bridging portion of the breaking line 12, and the circumferential breaking line 12 is broken. When the circumferential break line 12 is broken, the packing 6 that is in close contact with the mouth and neck portion 46 is formed separately from the shell 4, and thus is in close contact with the mouth and neck portion 46. Since only the shell 4 can be rotated without the packing 6 being rotated, the circumferential break line 12 can be broken sufficiently easily without requiring excessive torque.

  After the circumferential break line 12 is broken, the tamper evidence skirt 16 remains, and the top wall 8 of the shell 4 and the main portion 14 of the skirt wall 10 are raised with rotation. When the top surface wall 8 of the shell 4 and the main portion 14 of the skirt wall 10 are raised over the distance D1, as shown in FIG. 6, the upper edge of the inward displacement portion 30 generated in the shell 4 becomes the packing. 6 is brought into contact with the lower surface 42c of the flange 42. After that, the packing 6 is also raised with the rise of the top surface wall 8 of the shell 4 and the main portion 14 of the skirt wall 10, so that the packing 6 is separated upward from the mouth-and-neck portion 46 and the mouth-and-neck portion. 46 is released, and the packing 6 is detached from the mouth and neck portion 46 together with the top wall 8 of the shell 4 and the main portion 14 of the skirt wall 10, and the mouth and neck portion 46 is opened. The packing 6 is separated upward from the mouth-and-neck portion 46 and the sealing of the mouth-and-neck portion 46 is released. The circumferential break line 12 in the shell 4 is broken and the main wall 8 and the skirt wall 10 of the shell 4 are broken. After the portion 14 has been raised over the distance D1, the sealing of the mouth and neck portion 46 is not released prior to the breaking of the circumferential break line 12. When the inner displacement portion 30 of the shell 4 is brought into contact with the lower surface 42c of the flange 42 of the packing 6, the peripheral portion of the packing 6, particularly the flange 42, tends to bend upward and radially inward. Is limited by the contact of the outer peripheral surface of the additional drooping portion 40 with the inner peripheral surface of the inner displacement portion 30, and therefore the flange 6 of the packing 8 moves downward beyond the upper edge of the inner displacement portion 30 of the shell 4. In other words, the so-called slipping out of the upper end edge of the inner displacement portion 30 that moves upward beyond the flange 42 of the packing 8 is reliably prevented.

  When only a part of the contents of the container is consumed, the packing 6 held therein together with the top surface wall 8 of the shell 4 and the main portion 14 of the skirt wall 10 separated from the mouth-and-neck portion 46 is placed in the mouth-and-neck. The female thread 62 of the shell 4 is re-threaded with the male thread 48 of the mouth-and-neck part 46, and the mouth-and-neck part 46 can be resealed.

  In the embodiment described above, when opening the mouth and neck portion 46, the circumferential break line 12 formed in the skirt wall 10 of the shell 4 is broken over the entire circumferential direction, and the tamper evidence skirt portion 16 is formed. It is completely separated from the main part 14 of the skirt wall 10, but if desired, one or more axial break lines may be provided at the tamper evidence skirt 16 to open the mouth and neck 46. The circumferential rupture line is not completely ruptured, but part of it remains, and the axial rupture line is ruptured so that the tamper evidence hem is developed from an endless annular shape to an end band shape. The entire shell 4 including the hem portion can be detached from the mouth and neck portion 46.

Next, examples and comparative examples will be described.
Example 1
A mouth and neck shell having a nominal diameter of 38 mm was formed from an aluminum-based alloy having a thickness of 0.25 mm as shown in FIGS. 1 and 2. Further, a packing as shown in FIGS. 1 and 2 was formed from a blend resin of styrene elastomer and polypropylene. And this packing was inserted in the shell, and the container lid as illustrated in FIG.1 and FIG.2 was formed in this way. The inner peripheral surface of the outer seal ring in the packing had an inclination angle α of 30 degrees with respect to the central axis of the container lid, the upper end diameter of the inner peripheral surface was 32.60 mm, and the lower end diameter was 33.85 mm. The drooping length of the additional drooping portion that hangs down from the lower surface of the outer sealing ring is 0.9 mm, and the radial width of the shoulder surface between the inner peripheral surface of the outer seal ring and the inner peripheral surface of the additional drooping portion is 0. It was 25 mm. The radial width of the lower surface of the flange of the packing was 0.65 mm.

Drop impact test The product is sold by Toyo Seikan Co., Ltd. under the trade name “TEC200”, has a nominal diameter of 38 mm, and has a mouth-and-neck portion as shown in FIGS. 3, 4 and 8 and an internal volume of 215. A 5 ml chromic acid treated steel plate container was filled with 190 g of 85 ° C. ± 2 ° C. water. Next, the container lid was attached to the mouth and neck of the container in the manner described with reference to FIG. 4 to seal the mouth and neck. Thereafter, retorting was performed at 123 ° C. for 21 minutes, followed by slow cooling at room temperature (about 23 ° C.), and then storing in a storage room at 5 ° C., 23 ° C. and 60 ° C., respectively, for 24 hours. Storage), Sample B (23 ° C. storage) and Sample C (60 ° C. storage) were prepared.

  Each of the samples A, B, and C was subjected to 30 cm, 40 cm, and 50 cm drop impact tests in the following procedure. Steel whose samples A, B, and C in an inverted state are dropped by 30 cm, 40 cm, and 50 cm in cylinders that are arranged substantially vertically, respectively, and the upper surface is inclined at an inclination angle of 10 degrees with respect to the horizontal. It collided with the upper surface of the block. Then, it was confirmed whether or not a leak occurred due to a decrease in the reduced pressure value of the internal pressure of the container (determination that a leak occurred when the internal pressure increased to -30 KPa or more) and a leak of the filled water. The results of performing the drop impact test on 10 samples A, B and C are as shown in Table 1 below, and no leakage was observed.

Blow-off test The product is sold by Toyo Seikan Co., Ltd. under the trade name “TEC200”, has a nominal diameter of 38 mm, and has a mouth-and-neck portion as shown in FIGS. 3, 4 and 8 with an internal volume of 215. A 5 ml chromic acid-treated steel plate container was filled with 190 g of 85 ° C. ± 2 ° C. water. Next, the container lid was attached to the mouth and neck of the container in the manner described with reference to FIG. 4 to seal the mouth and neck. Thereafter, it was retorted at 123 ° C. for 21 minutes, then slowly cooled at room temperature (about 23 ° C.), and then stored in a 23 ° C. storage room for 24 hours. After that, once the container lid is removed from the mouth and neck of the container, the mouth and neck is opened, water is substantially completely discharged, 190 ml of citric acid solution is filled, and the internal pressure of the container becomes 0.8 MPa. The prepared sodium bicarbonate particles were added, and an easy lid was again temporarily attached to the mouth and neck to seal the mouth and neck. Subsequently, it was stored in a storage room at 23 ° C. for 72 hours, and thus sample D was prepared.

  About the sample D, the container lid attached to the mouth-and-neck portion was manually manually rotated suddenly in the opening direction, and it was confirmed whether or not the container lid flew at this time. The fact that the lid did not fly means that the internal pressure of the container was appropriately released. The results of performing the blow-off test on 100 samples D are as shown in Table 2 below, and none of the container lids flew.

Comparative Example 1
The inner peripheral surface of the outer seal ring in the packing has an inclination angle α of 15 degrees with respect to the central axis of the container, and the diameter at the lower end of the inner peripheral surface is 33.55 mm. A container lid was created.

Drop impact test And as a result of performing the drop impact test in the same manner as the drop impact test in Example 1, as shown in Table 1 below, no occurrence of leakage was observed.

Blow-off test The blow-off test was also performed in the same manner as the blow-off test in Example 1. The result is as shown in Table 2 below, and when two natural flying occurs where the container lid flew before manually rotating the container lid, and when manually rotating it suddenly in the opening direction, There were three things that the container lid flew. This fact indicates that the internal pressure of the container was not properly released.

Comparative Example 2
The inner peripheral surface of the outer seal ring in the packing has an inclination angle α of 45 degrees with respect to the central axis of the container, and the diameter at the lower end of the inner peripheral surface is 34.35 mm. A container lid was created.

Drop impact test And, as a result of performing the drop impact test in the same manner as the drop impact test in Example 1, as shown in Table 1 below, 1 to 4 samples A, B and C Occurrence of leakage was observed in

Blow-off test The blow-off test was also performed in the same manner as the blow-off test in Example 1. The results are as shown in Table 2 below, and any container lid could fly.

The front view which shows a suitable embodiment of the container lid comprised according to this invention in part with sectional drawing. The expanded partial sectional view which shows a part of container lid of FIG. The front view which shows a state with which the container lid of FIG. 1 was covered by the mouth neck part in order to mount | wear with the mouth neck part of a container, with a sectional view. The front view which shows the state which mounted | wore the container neck of FIG. The partial expanded sectional view which shows the state which mounted | wore the container neck of FIG. 1 to the mouth neck part of the container as needed. The front view which shows a state in which the shell is raised with respect to the packing and the inward displacement portion of the shell is in contact with the lower surface of the annular flange of the packing when opening the mouth and neck of the container.

Explanation of symbols

2: Container lid 4: Shell 6: Packing 8: Top wall 10: Skirt wall 12: Circumferential rupture line 14: Main part of skirt wall 16: Tamper evidence hem part 26: Vent hole 28: Horizontal slit 30: Inward Displacement portion 32: main wall portion 34: annular protrusion 36: outer seal ring 36a: inner peripheral surface of outer seal ring
38: Inner annular ring 40: Additional hanging portion 40a: Inner circumferential surface of additional hanging portion 40b: Outer circumferential surface of additional hanging portion 42: Flange 42c: Lower surface of flange 46: Mouth and neck portion of container

Claims (6)

A shell made of a thin metal plate and a synthetic resin packing, the shell having a top wall and a skirt wall depending from the periphery of the top wall, and a circumferential break line extending in the circumferential direction on the skirt wall The skirt wall is divided into a main part above the circumferential break line and a tamper evidence skirt below the circumferential break line, and the upper part of the main part is A plurality of ventilation holes are provided at intervals in the circumferential direction, and each of the ventilation holes forms a horizontal slit extending substantially horizontally, forcing the lower part of the horizontal slit radially inward. In the container lid formed by generating the inward displacement portion,
The packing has a disk-shaped main wall as a whole, an annular outer seal ring that hangs from the lower surface of the peripheral edge of the main wall, an additional drooping portion that further hangs from the lower surface of the outer seal ring, and the outer side of the outer seal ring Having an annular flange located at
The inner peripheral surface of the outer seal ring is radially outwardly directed downward at an inclination angle α of 20 to 40 degrees with respect to the central axis of the container lid before the container lid is attached to the mouth / neck portion of the container. It is in the shape of a truncated cone that tilts in the direction, and when the container lid is attached to the mouth and neck of the container, it is brought into close contact with the upper outer peripheral surface of the mouth and neck,
The inner peripheral surface of the additional drooping portion is displaced radially outward with respect to the inner peripheral surface of the outer seal ring, and even when the container lid is attached to the mouth and neck of the container, The outer peripheral surface of the additional drooping portion is located immediately inside the inward displacement portion of the shell in a radial direction without being intimately contacted;
The bottom surface of the flange is positioned opposite to the upper end edge of the inward displacement portion of the shell with a distance D1 of 0.3 to 3.5 mm in a state where the container lid is attached to the mouth and neck of the container. To
A container lid characterized by that.   In a state where the container lid is mounted on the mouth and neck of the container, the radial distance D2 between the outer peripheral edge of the lower surface of the flange of the packing and the minimum inner peripheral edge of the upper end edge of the inward displacement portion of the shell is 0.1 to The container lid according to claim 1, which is 1.0 mm.   When the container lid is attached to the mouth and neck of the container, the outer peripheral surface of the additional hanging portion of the packing has an inverted truncated cone shape that is inclined radially inward downward, and the additional hanging portion in the radial direction. 3. The container lid according to claim 1, wherein an upper end of the outer peripheral surface of the shell and a minimum inner peripheral edge of the upper end edge of the inner displacement portion of the shell are substantially aligned.   The container lid according to any one of claims 1 to 3, wherein an annular ridge is formed on an upper surface of the peripheral edge of the packing, and the annular ridge is brought into contact with the inner surface of the top wall of the shell. .   An annular inner ring that hangs radially inward from the outer seal ring is also formed on the lower surface of the packing. The inner ring is attached to the mouth and neck of the container when the container lid is attached to the container neck. The container lid according to any one of claims 1 to 4, wherein the container lid is inserted into the mouth and neck.   The boundary between the top wall and the skirt wall of the shell is immersed downward and radially inward when mounted on the mouth and neck of the container. Container lid.

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