JP6932705B2 - Resin cap - Google Patents

Description

The present invention relates to, for example, a resin cap attached to the mouth of a container for accommodating contents such as beverages.

As a conventional resin cap, an annular inner seal protrusion fitted into the container mouth portion and an opening of the container mouth portion are provided on the inner surface of the top plate portion of the cap body having a top plate portion and a tubular portion hanging from the peripheral edge thereof. An annular open-end seal protrusion that abuts on the end is formed, and it is known that this open-end seal protrusion is bent and deformed in the diameter-expanding direction until it abuts on the cap body by the container mouth when the cap is attached. (Patent Document 1).

With such a resin cap, even if the container mouth is easily bent and deformed in the radial direction due to the bulging deformation of the top plate as the pressure inside the container rises, the open end seal is used. It is said that the protrusions can reliably seal the open end and maintain high sealing performance.

JP-A-2002-68236

However, the conventional resin cap has room for improving moldability and sealing property.

The present invention has been made in consideration of the above-mentioned matters, and an object of the present invention is to provide a resin cap which is excellent in moldability and can also improve the sealing property.

In order to achieve the above object, the resin cap according to the present invention has a top wall and a skirt wall having a female screw extending downward from the outer peripheral portion of the top wall and screwing into a male screw at the mouth of the container. On the lower surface of the top wall, an annular middle leg that adheres to the inner peripheral surface of the container mouth portion, an annular rib that adheres to the annular upper end surface of the container mouth portion, and an outer peripheral surface of the container mouth portion. the inner peripheral surface Ri integrally formed tare the outer leg of the annular shape in close contact, the annular rib, resin cap at a position spaced from the metatarsal and the outer leg at the lower surface of the top wall The outer diameter of the middle foot is the maximum at the maximum outer diameter formed between the base end and the tip of the middle foot, and the outer foot is outside the base end of the middle foot. It extends to a position corresponding to the maximum diameter, the inner peripheral surface of the outer foot expands downward, the outer peripheral surface contracts downward, and the taper angle of the inner peripheral surface is used. The taper angle of the outer peripheral surface is increased (claim 1).

In the resin cap, the taper angle of the inner peripheral surface may be 5 ° or more, and the taper angle of the outer peripheral surface may be 20 ° or less (claim 2).
The resin cap may have a lower surface located on the inner peripheral side of the outer leg formed above the lower surface located on the outer peripheral side of the top wall (claim 3).
The resin cap is a length of the outer leg and more than 1.35mm may be I Thea (claim 4).

According to the present invention, a resin cap having excellent moldability and, by extension, improving hermeticity can be obtained.

That is, in the resin cap of the invention according to each claim of the present application, since a portion requiring forcible punching is not formed on the outer leg, the die-cutting property (moldability) can be improved, and the outer surface of the outer leg can be improved. Since the taper angle on the side is larger than the taper angle on the inner surface side and the outer leg is less likely to be elastically deformed in the diameter expansion direction, the adhesion force of the outer leg to the container mouth portion is increased, and thus the sealing property can be improved.

It is a bottom view which shows schematic structure of the resin cap which concerns on one Embodiment of this invention. FIG. 1 is a cross-sectional view taken along the line AA of FIG. FIG. 1 is a cross-sectional view taken along the line BB of FIG.

Embodiments of the present invention will be described below with reference to the drawings.

The resin cap (hereinafter referred to as a cap) 1 shown in FIGS. 1 to 3 is used by being attached to the mouth M (see FIG. 3) of a container such as a PET bottle, and is used by compression molding or injection molding. Is integrally molded with polyethylene. The material for forming the cap 1 is not particularly limited, and polypropylene or the like is preferably used in addition to the polyethylene used in the present embodiment.

Further, as shown in FIGS. 1 and 2, the cap 1 has a substantially circular top wall 2 in a plan view and a substantially cylindrical skirt wall 3 extending downward from the outer peripheral portion of the top wall 2. There is. Here, a knurled groove 4 is provided on the outer peripheral surface of the skirt wall 3, and a female screw 5 is provided on the inner peripheral surface, and the female screw 5 is connected to a male screw M1 (see FIG. 3) formed on the outer periphery of the container mouth. It is possible.

Then, when the cap 1 is rotated and attached to the container mouth M so that the female screw 5 of the skirt wall 3 is connected to the male screw M1 of the container mouth M, an annular ring is continuously provided on the inner surface (lower surface) of the top wall 2. The middle leg (inner ring) 6, the annular rib 7, and the annular outer leg (outer ring) 8 are in close contact with the container opening M, whereby the container opening is sealed (see FIG. 3). That is, as shown by a virtual line in FIG. 3, when the cap 1 is attached to the container mouth M, the middle leg 6 is inserted into the container mouth M and comes into close contact with the inner peripheral surface of the container mouth M. The annular rib 7 is configured to be in close contact with the annular upper end surface of the container mouth M, and the outer leg 8 is configured to be in close contact with the outer peripheral surface of the container mouth M.

Further, the cap 1 is a pilfer-proof cap having a function of proving that it has not been opened (it has never been opened), and when the unopened cap 1 attached to the container opening M is opened (first). When the cap 1 is rotated so that the connection between the male screw M1 and the female screw 5 is released at the time of opening the cap 1, the cap 1 is separated from the container mouth M, but the tamper evidence is connected to the lower part of the skirt wall 3. The band (hereinafter, simply referred to as “band”) 9 is configured to remain in the container mouth portion M.

That is, a band 9 is connected to the lower part of the skirt wall 3 via an annular weakening portion 10 extending over the entire circumference of the skirt wall 3 (see FIG. 3), and the annular weakening portion 10 is formed between the skirt wall 3 and the band 9. The bridge 10a is composed of a plurality of bridges 10a existing on the inner peripheral side of the boundary with the skirt wall 3 and slits 10b extending in the circumferential direction of the skirt wall 3 and the band 9 so as to vertically delineate the skirt wall 3 and the band 9. A part (outer peripheral portion) of the bridge 10a is also cut by the slit 10b so that the bridge 10a breaks when pulled by a predetermined force.

Further, on the inner peripheral side of the band 9, a plurality of locking pieces (flaps) 11 protruding inward are provided at intervals in the circumferential direction (8 in this example) (see FIGS. 1 to 3). ). Each locking piece 11 is positioned substantially below the annular protrusion (bead portion) M2 formed below the male screw M1 on the outer periphery of the container mouth portion M with the cap 1 attached to the container mouth portion M. Then, it is locked to the annular protrusion M2 by the opening operation (see FIG. 3). That is, the locking piece 11 is configured to be able to be locked to the annular protrusion M2 from below, and when opened, the cap body portion (skirt wall 3 and top wall 2) above the annular weakening portion 10 is the container mouth portion. The band 9 which is separated from M and is below the annular weakening portion 10 remains in the container mouth portion M, and the annular weakening portion 10 is broken accordingly.

Here, the band 9 is integrally molded with the cap main body (skirt wall 3 and top wall 2), and the locking piece 11 provided on the band 9 projects downward as shown in FIG. 2 when the cap 1 is molded. However, when the cap 1 is attached to the container mouth portion M, it is pushed up by the annular protrusion M2 and inverted, and as shown by a virtual line in FIG. 3, it protrudes upward.

Then, in the present embodiment, as shown in FIG. 3, the outer leg 8 extends 1.35 mm or more below the lower surface 2a located on the outer peripheral side of the outer leg 8 on the top wall 2. That is, the length L of the outer leg 8 (the length protruding from the lower surface 2a of the top wall 2) L is set to 1.35 mm or more, which is longer than the general one. As a result, the area where the outer leg 8 can be brought into close contact with the outer peripheral surface of the container mouth portion M is increased, and the sealing property can be improved. Specifically, the length L of the outer leg 8 can be 1.58 mm, 1.78 mm, or the like.

Here, the outer diameter of the middle foot 6 is maximum at the outer diameter maximum portion 6a formed between the base end and the tip of the middle foot 6, and the outer foot 8 is outside from the base end of the middle foot 6. It extends to a position corresponding to the maximum diameter portion 6a.

Further, in the present embodiment, as shown in FIG. 3, the inner peripheral surface of the outer leg 8 expands in diameter downward, the outer peripheral surface decreases in diameter downward, and the outer peripheral surface is outer peripheral than the taper angle α of the inner peripheral surface. The taper angle β of the surface is increased. Specifically, it is conceivable that the taper angle α of the inner peripheral surface is 5 ° or more and the taper angle β of the outer peripheral surface is 20 ° or less. With such a configuration, since a portion requiring forcible punching is not formed on the outer leg 8, the die-cutting property (formability) can be improved, and the taper angle β on the outer surface side of the outer leg 8 is on the inner surface side. Since the outer leg 8 is larger than the taper angle α and is unlikely to be elastically deformed in the diameter-expanding direction, the adhesion force of the outer leg 8 to the container mouth portion M is increased, and thus the sealing property can be improved. The latter effect is further enhanced by forming the lower surface 2b located on the inner peripheral side of the outer leg 8 on the top wall 2 above the lower surface 2a located on the outer peripheral side. Specifically, the taper angle α of the inner peripheral surface is set to 10 °, the taper angle β of the outer peripheral surface is set to 15 °, the taper angle α of the inner peripheral surface is set to 5 °, and the taper angle β of the outer peripheral surface is set to 10 °. The difference between the taper angles α and β is preferably 3 to 10 °, and more preferably about 5 ° or 5 ° (4 ° to 6 °).

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention can be variously modified and implemented without departing from the gist of the present invention. For example, the following modification examples can be given.

In the above embodiment, the lower surface 2b located on the inner peripheral side of the outer leg 8 is formed above the lower surface 2a located on the outer peripheral side of the top wall 2, but the lower surfaces 2a and 2b are not limited to this. It may be formed at the same height, or the lower surface 2a may be formed above the lower surface 2b.

As shown in FIGS. 2 and 3, the middle foot 6 projects downward from the outer foot 8, and the container mouth portion M contacts the middle foot 6 before the outer foot 8 during capping. Therefore, it is shown in FIG. In the example, the thickness of the base end of the outer foot 8 (width in the inner and outer diameter directions) is made larger than the thickness of the base end of the middle foot 6 (width in the inner and outer diameters), and the middle foot 6 is larger than the outer foot 8. By making it relatively easy to deform, the initial resistance at the time of capping is suppressed to be relatively small, and when the capping is completed, the outer leg 8 is brought into close contact with the container mouth portion M so that sufficient sealing performance can be obtained. Not limited to this, the thickness of the base end portion of the middle foot 6 may be equal to or greater than the thickness of the base end portion of the outer foot 8.

Further, in the above embodiment, the length L of the outer leg 8 is 1.35 mm or more, but it may be shorter than this.

Needless to say, the above modified examples may be combined as appropriate.

The resin cap according to the present invention can be used for a container containing various beverages in addition to fruit juice beverages and carbonated beverages, as well as liquids and powders other than beverages.

1 Cap 2 Top wall 2a Lower surface located on the outer peripheral side of the outer foot 2b Lower surface located on the inner peripheral side of the outer foot 3 Skirt wall 4 Laurette groove 5 Female screw 6 Middle foot 6a Outer diameter maximum part 7 Circular rib 8 Outer foot 9 Tamper Evidence band 10 Ring weakening part 10a Bridge 10b Slit 11 Locking piece L Length of outer foot M Container mouth M1 Male screw M2 Ring protrusion α Tapered angle of inner peripheral surface of outer foot β Tapering angle of outer peripheral surface of outer foot

Claims (4)

A top wall and a skirt wall having a female screw extending downward from the outer peripheral portion of the top wall and screwing into the male screw of the container mouth portion are provided, and the lower surface of the top wall has an inner circumference of the container mouth portion. An annular middle leg that is in close contact with the surface, an annular rib that is in close contact with the annular upper end surface of the container mouth portion, and an annular outer leg that is in close contact with the outer peripheral surface of the container mouth portion. formed tear is, the annular rib is a resin cap in the position separated from the metatarsal and the outer leg at the lower surface of the top wall,
The outer diameter of the middle foot is the maximum at the maximum outer diameter formed between the base end and the tip of the middle foot, and the outer foot extends from the base end to the maximum outer diameter of the middle foot. Extends to the corresponding position between
The inner peripheral surface of the outer leg is enlarged downward, the outer peripheral surface is reduced in diameter downward, and the taper angle of the outer peripheral surface is larger than the taper angle of the inner peripheral surface. Resin cap. The resin cap according to claim 1, wherein the taper angle of the inner peripheral surface is 5 ° or more, and the taper angle of the outer peripheral surface is 20 ° or less. The resin cap according to claim 1 or 2, wherein the lower surface of the top wall located on the inner peripheral side of the outer leg is formed above the lower surface located on the outer peripheral side. The resin cap according to any one of claims 1 to 3, wherein the length of the outer leg is 1.35 mm or more.

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