JP7141812B2 - Container lid with metal body and synthetic resin liner - Google Patents

Description

The present invention is a container comprising a sheet metal main body having a circular top wall and a cylindrical skirt wall hanging down from the periphery of the top wall, and a synthetic resin liner disposed on the inner surface of the top wall of the main body. Regarding the lid.

It is made of a thin metal plate such as an aluminum-based alloy, and has an outer curl formed at the upper end of the cylindrical mouth and neck portion, and a female screw thread and a locking jaw located below it on the outer peripheral surface of the mouth and neck portion. Patent Documents 1 and 2 below disclose a circular top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall as a container lid particularly suitable for a container generally called a bottle can. and a synthetic resin liner disposed on the inner surface of the top wall of the main body. An annular recess is formed in the upper end of the skirt wall of the body. The liner is formed by embossing a first layer formed by embossing a hard synthetic resin material supplied to the inner surface of the top wall, and by embossing a soft synthetic resin material supplied to the lower surface of this first layer. and a second layer. The first layer of the liner includes a circular central portion extending along the inner surface of the top wall of the main body and an outer annular portion extending along the outer peripheral edge of the top wall of the main body and the upper end of the skirt wall. It has a peripheral edge and the second layer of liner is laminated to the central portion of the first layer.

Japanese Patent Application Laid-Open No. 2015-3325 Japanese Patent Application Laid-Open No. 2016-26961

According to the experience of the present inventors, the above-described conventional container lid has the following drawbacks: (1) a radially inner region at the outer peripheral edge of the first layer when the second layer is stamped; (2) When the second layer is stamped, the synthetic resin for molding the second layer is sufficiently smooth. It has been found that there is a problem to be solved that it may not flow as desired and it may not be possible to stamp the second layer with the desired shape.

The present invention has been made in view of the above facts, and its main technical problem is to emboss the second layer without causing separate problems such as a considerable increase in the amount of material used. A new and improved structure which avoids, as far as possible, damage to the radially inner region at the outer peripheral edge of the first layer , and also ensures that the desired shape of the second layer can be embossed. It is to provide a container lid that is made to last.

As a result of intensive research and incidents, the inventors of the present invention have found that the reason why the radially inner region of the outer peripheral edge of the first layer is damaged when the second layer is stamped is that the adjacent central portion is usually damaged. Against the fact that the thickness of the radially inner region of the outer peripheral edge, which is identical to the thickness of the radially outer region, is too small so that the mold parts for stamping the second layer abut with a considerable pressing force. I recognized that it was caused by not having sufficient resistance to Based on this recognition, the thickness of the radially inner region of the outer peripheral edge of the first layer is made larger than the thickness of the radially outer region of the central portion to form a step at the boundary between the central portion and the outer peripheral edge. It has been found that the first problem can be solved by allowing the step to exist (the first problem can be solved even if the thickness of the radially outer region of the central portion is similarly increased to prevent the step from existing). possible, but doing so would increase the amount of material required to mold the first layer). Further, as a result of intensive studies and experiments, it was found that the second layer was formed by embossing when an annular thickness variation region in which the thickness gradually decreased radially outward was provided in the central portion of the first layer. It has been found that the synthetic resin material for molding the second layer can flow sufficiently smoothly when molding.

That is, according to the present invention, as a container lid for achieving the above main technical problems, a sheet metal body having a circular top wall and a cylindrical skirt wall hanging down from the peripheral edge of the top wall; a synthetic resin liner disposed on the inner surface of the top wall,
A boundary region between the top wall and the skirt wall in the main body has an arcuate cross section, and an annular recess extending continuously in the circumferential direction is formed at the upper end of the skirt wall,
The liner is formed by embossing a first layer formed by embossing a hard synthetic resin material supplied to the inner surface of the top wall and a soft synthetic resin material supplied to the lower surface of the first layer. It consists of a second layer molded by
The first layer of the liner includes a circular central portion extending along the inner surface of the top wall of the main body, the inner surface of the outer peripheral edge portion of the top wall of the main body, and the inner surface of the upper end portion of the skirt wall. and an annular outer peripheral edge that extends through and is arcuate in cross section,
The second layer of the liner is laminated on the central portion of the first layer and has a circular thin central portion and an annular thick outer peripheral edge portion. is brought into close contact with the mouth and neck of the container,
In the container lid,
The thickness of the radially inner region of the outer peripheral edge of the first layer of the liner is greater than the thickness of the radially outer region of the central portion, and a step is provided at the boundary between the central portion and the outer peripheral edge of the liner. exists and
In the central portion of the first layer, there is an annular thickness variation region whose thickness gradually decreases radially outward, and the outer peripheral edge of the thickness variation region is the second layer. located radially inward of and adjacent to the inner peripheral edge of the thickened outer peripheral edge;
There is provided a container lid characterized by:

The step is preferably 0.05 to 0.40 mm . Advantageously , there is a downwardly projecting annular projection in the radially inner region of the thickened peripheral edge of the second layer. Advantageously, in the region of the thin central portion of the second layer facing the thickness variation region, the thickness gradually increases radially outward in accordance with the thickness variation of the thickness variation region. . Preferably, the thickness variation region is inclined at an inclination angle of 0.5 to 3.0 degrees with respect to the horizontal. Applied to a sheet metal container having an outer curl formed at the tip of the neck portion, and the outer peripheral surface of the annular protrusion of the second layer of the liner is at the upper end of the inner peripheral surface of the outer curl. Advantageously, the lower surface of the radially outer region of the thickened outer peripheral edge, which is in close contact and is located radially outwardly of the annular projection, is in close contact with the upper surface or outer peripheral surface of the unturned curl.

The terms "upper" and "lower" as used herein and in the claims mean above and below the container lid in its upright position (ie, the position shown in FIGS. 1-3).

In the container lid of the present invention, the thickness of the radially inner region of the outer peripheral edge of the first layer of the liner is greater than the thickness of the radially outer region of the central portion, and the boundary between the central portion and the outer peripheral edge is The thickness of the radially inner region of the outer peripheral edge of the first layer of the liner should be sufficient without the presence of a step and, therefore , excessively increasing the amount of material required to mold the first layer. This makes it possible to avoid damage to the radially inner region of the outer peripheral edge of the first layer when the second layer is embossed. In addition, in the central portion of the first layer, there is an annular thickness variation region in which the thickness gradually decreases radially outward. The flow of the material is promoted during press molding, and the second layer of the desired shape can be reliably press molded.

1 is a front view, partially in section, of a preferred embodiment of a container closure constructed in accordance with the present invention; FIG. The enlarged view which expands and shows a part of FIG. FIG. 2 is a front view partially showing a cross section of a state in which the container lid shown in FIG. The enlarged view which expands and shows a part of FIG.

Reference will now be made in more detail to the accompanying drawings which illustrate preferred embodiments of container closures constructed in accordance with the present invention.

Referring to FIG. 1, a container lid, generally designated 2, constructed in accordance with the present invention comprises a sheet metal body 4 and a synthetic resin liner 6. As shown in FIG.

The body 4, which can be formed from a suitable sheet metal such as an aluminum-based alloy sheet, has a circular top wall 8 and a cylindrical skirt wall 10 depending from the periphery of the top wall 8. As shown in FIG. A boundary region between the top wall 8 and the skirt wall 10 has an arc shape in cross section. An annular recess 12 extending continuously in the circumferential direction is formed in the upper end of the skirt wall 10 . A plurality of slits (notches) 14 extending in the circumferential direction are formed in a region immediately below the annular recess 12, and the region located below the slits 14 extends radially inward. displaced in the direction of A circumferentially breakable line 16 is provided at the lower end of the skirt wall 10 , and the skirt wall 10 has a main portion 18 above the circumferentially breakable line 16 and a temper portion below the circumferentially breakable line 16 . It is divided into an evidence skirt portion 20 and the evidence skirt portion 20 . The circumferential breakable line 16 in the illustrated embodiment is composed of a plurality of circumferentially extending slits 22 spaced apart in the circumferential direction and a plurality of bridging portions 24 remaining between the slits 22. The tamper-evident skirt portion 20 is connected to the main portion 18 via a plurality of bridging portions 24 . Such body 4 itself is of well-known form and therefore a detailed description of body 4 is omitted herein.

Continuing with FIG. 2 in conjunction with FIG. 1, liner 6 is comprised of first layer 26 and second layer 28 . The first layer 26 is formed by embossing a synthetic resin material supplied to the inner surface of the top wall 8 of the main body 4 . More specifically, the main body 4 is held on a base (not shown) in an inverted state, a synthetic resin material in a softened and melted state is supplied to the central portion of the top wall 8, and a desired shape is formed on the synthetic resin material. It is shaped by pressing a embossing member (not shown) with the required pressure. It is important that the first layer 26 is molded from a hard synthetic resin such as polyethylene or polypropylene which has excellent gas barrier properties. Accordingly, the first layer 26 has a higher gas barrier property than the second layer 28 constituting the sealing layer. The second layer 28 is formed by stamping a synthetic resin material supplied to the underside of the first layer 26 . More specifically, the main body 2 having the first layer 26 formed thereon is held upside down on a base (not shown), and a softened and melted synthetic resin material is supplied to the central portion of the first layer 26. The synthetic resin material is molded by pressing a embossing member (not shown) having a required shape with a required pressure. It is important that the second layer 28 is molded from a soft synthetic resin such as polyethylene or elastomer which has excellent sealing properties.

The first layer 26 extends along a circular center portion 30 extending along the inner surface of the top wall 8 of the main body 4, the inner surface of the outer peripheral edge portion of the top wall 8 of the main body 4, and the inner surface of the upper end portion of the skirt wall 10. It has an annular outer peripheral edge portion 32 that fits. The central portion 30 has an annular thickness variation region 34 whose thickness gradually decreases radially outward (therefore, the lower surface extends radially outward at an upward inclination), The outer peripheral edge of the thickness variation region 34 is located radially inwardly of the inner peripheral surface of the thick outer peripheral edge portion 38 (described later) of the second layer 28 (therefore, the inner peripheral edge of the annular projecting portion 40 described later). is important . The inclination angle α of the lower surface of the thickness variation region 34 with respect to the horizontal is preferably 0.5 to 3.0 degrees . The thickness of the radially inner region of the outer peripheral edge 32 of the first layer 26 is greater than the thickness of the radially outer region of the central portion 30, and the boundary between the central portion 30 and the outer peripheral edge 32 preferably has a thickness of 0.05 mm. It is important that there is a step s which is on the order of 0.40 mm.

The second layer 28 laminated on the central portion 30 of the first layer 26 has a circular thin central portion 36 and an annular thick peripheral edge portion 38 . In the radially inner region of the outer peripheral edge 38 there is a downwardly projecting annular projection 40 .

In the container lid 2 constructed in accordance with the present invention, the thickness of the radially inner region of the outer peripheral edge portion 32 of the first layer 26 constituting the liner 6 is greater than the thickness of the radially outer region of the central portion 30, A step s exists at the boundary between the central portion 30 and the outer peripheral edge portion 32. In other words, the thickness of the radially inner region of the outer peripheral edge portion 32 of the first layer 26 is relatively large. It is possible to avoid damage to the outer peripheral edge 32 of the first layer 26 caused by the embossing member acting on the radially inner region of the outer peripheral edge 32 of the first layer 26 during molding. be done. The thickness of the radially outer region of the central portion 30 of the first layer 26 is relatively small so that the amount of synthetic resin material for molding the first layer 26 is not excessively increased. Furthermore, in the container lid 2 constructed in accordance with the present invention, the central portion 30 of the first layer 26 has a thickness variation region 34 in which the thickness gradually decreases radially outward, so that the second layer When the second layer 28 is formed by stamping, the synthetic resin material flows sufficiently smoothly radially outward, so that the second layer 28 having the required shape can be formed with sufficient reliability.

Figures 3 and 4 also show a container neck 42 to which the container lid 2 is applied. The container neck 42, which is of a form known per se, which may be formed from any suitable sheet metal such as chromated steel sheet, tin sheet, or aluminum-based alloy sheet, is generally generally cylindrical in shape, An outer curl 44 is formed at the upper end where the outer diameter gradually decreases upward. A male thread 46 and a locking jaw 48 positioned below the male thread 46 are formed on the outer peripheral surface of the main portion of the mouth/neck portion 42 .

When the container lid 2 is attached to the mouth/neck portion 42 of the container and the mouth/neck portion 42 is sealed, the container lid 2 is fitted over the mouth/neck portion 42 and pressed downward to remove the second layer 28 of the liner 6. The state of being brought into close contact with the top of the mouth/neck portion 42, more specifically, the outer peripheral surface of the annular protrusion 40 of the second layer 28 and the radially outer side of the thick outer peripheral edge portion 38 located radially outside the annular protrusion 40. While maintaining the lower surface of the region in close contact with the upper end or upper surface of the inner peripheral surface of the outer curl 44 of the mouth and neck portion 40, the outer peripheral edge portion of the top wall 8 of the main body 2 and the upper end portion of the skirt wall 10 are moved. and deforms into the shape as shown in FIG. As a result, the outer peripheral surface of the annular protrusion 40 of the second layer 28 of the liner 6 is brought into close contact with the upper end of the inner peripheral surface of the outer curl 44, and the thick outer peripheral edge located radially outside the annular protrusion 40. The lower surface of the radially outer region of portion 38 is brought into intimate contact with the upper or outer peripheral surface of outer curl 44 . Further, the main portion 18 of the skirt wall 10 of the main body 2 is deformed along the male thread 46 formed in the mouth/neck portion 42 of the container to form the female thread, and the tampering in the skirt wall 10 of the main body 2 is performed. The lower end of evidence skirt 20 is deflected radially inward to engage locking jaws 48 on container neck 42 .

When opening the mouth/neck portion 42 to consume the contents of the container, put a finger on the skirt wall 8 of the main body 4 to open the container lid 2, that is, in the counterclockwise direction as viewed from above in FIG. Rotate. Thus, the female thread formed on the main portion 18 of the skirt wall 10 moves along the male thread 46 of the neck portion 42, so that the container lid 2 is moved upward with respect to the neck portion 42. . On the other hand, the tamper-evident bottom portion 20 of the skirt wall 10 is formed on the skirt wall 10 so that its lower end portion is locked by the locking jaw portion 48 of the mouth/neck portion 42 so that upward movement is prevented. A stress is generated in the bridge 24 at the circumferential breakable line 16 causing the bridge 24 to break. After that, the container lid 2 is rotated and moved upward leaving the tamper-evident bottom portion 20 to be separated from the mouth/neck portion 42, and the mouth/neck portion 42 is unsealed.

2: Container lid 4: Main body 6: Liner 8: Top wall 10: Skirt wall 26: First layer 28: Second layer 30: Central part of first layer 32: Peripheral edge part of first layer 34: Thickness variation Region 36: Thin center portion of second layer 38: Thick outer peripheral edge portion of second layer 40: Annular protruding portion 42: Mouth and neck portion of container

Claims (6)

A thin metal plate main body having a circular top wall and a cylindrical skirt wall hanging down from the peripheral edge of the top wall, and a synthetic resin liner disposed on the inner surface of the top wall of the main body,
A boundary region between the top wall and the skirt wall in the main body has an arcuate cross section, and an annular recess extending continuously in the circumferential direction is formed at the upper end of the skirt wall,
The liner is formed by embossing a first layer formed by embossing a hard synthetic resin material supplied to the inner surface of the top wall and a soft synthetic resin material supplied to the lower surface of the first layer. It consists of a second layer molded by
The first layer of the liner includes a circular central portion extending along the inner surface of the top wall of the main body, the inner surface of the outer peripheral edge portion of the top wall of the main body, and the inner surface of the upper end portion of the skirt wall. and an annular outer peripheral edge that extends through and is arcuate in cross section,
The second layer of the liner is laminated on the central portion of the first layer and has a circular thin central portion and an annular thick outer peripheral edge portion. is brought into close contact with the mouth and neck of the container,
In the container lid,
The thickness of the radially inner region of the outer peripheral edge of the first layer of the liner is greater than the thickness of the radially outer region of the central portion, and a step is provided at the boundary between the central portion and the outer peripheral edge of the liner. exists and
In the central portion of the first layer, there is an annular thickness variation region whose thickness gradually decreases radially outward, and the outer peripheral edge of the thickness variation region is the second layer. located radially inward of and adjacent to the inner peripheral edge of the thickened outer peripheral edge;
A container lid characterized by: 2. The container lid according to claim 1, wherein said step is 0.05 to 0.40 mm. 3. A container closure according to claim 1 or 2 , wherein a radially inner region of said thickened outer peripheral edge of said second layer has a downwardly projecting annular projection. 2. From claim 1 , wherein the thickness of a region facing the thickness variation region in the thin center portion of the second layer gradually increases radially outward in accordance with the thickness variation of the thickness variation region. 3. A container lid according to any one of 3 to 3 . 5. A container lid according to any one of claims 1 to 4 , wherein said thickness variation region is inclined at an inclination angle of 0.5 to 3.0 degrees with respect to the horizontal. Applied to a sheet metal container having an outer curl formed at the tip of the mouth and neck, and the outer peripheral surface of the annular protrusion of the second layer of the liner is at the upper end of the inner peripheral surface of the outer curl. 4. The container according to claim 3 , wherein the lower surface of the radially outer region of the thick-walled outer peripheral portion, which is in close contact and is located radially outwardly of the annular protrusion, is in close contact with the upper surface or outer peripheral surface of the outer curl. lid.

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