JP2000289758A - Shock-resistant easily openable container lid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To absorb and lighten an inverted drop impact and to reduce spurting- out of liquid from a sealed-up part while making a visual discernment of preservation of sealability possible by a method wherein an upwardly protuberant elastically deformative and restorable part is provided at the top face through a circumferential joint positioned at the inside of an inner peripheral edge of a sealing gasket. SOLUTION: For the present container lid, an upwardly protuberant, elastically deformative and restorable part, namely a button 5, is provided, through a circumferential joint 17, at its center panel 16 positioned at the inside of an inner peripheral edge of a groove 13. The height and the projected area of the upwardly protuberant part are desirable to be within a range of 0.3-0.7 mm for the height and 19.5-38.5 cm2 for the area, considering matters including absorption of impact on water hammering, functions such as strength, sealability and the like of the container lid and reversing and restoring capacities of the upwardly protuberant part. With an impact of water-hammering applied to the container lid, the button 5 is bent, being protuberant toward the inside of the container, and restored to its original state of protruding outward, and thereby the impact is absorbed and lightened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easily-openable container lid excellent in impact resistance, and more particularly, to an impact-resistant easy-open characteristic in which liquid splash due to an inverted drop impact (water hammer) is reduced. Related to container lid.

[0002]

2. Description of the Related Art Sake and other beverages are widely marketed in glass cup containers. The metal cap used for this type of cup container is with a tab ring, and the widely used one is to grip the tab and pull it to shear the score formed on the cap side wall. Then, the ring is removed, and the remaining part is opened by pushing up with a finger.

Japanese Patent No. 2632769 proposes a cap in which slits are formed at a position 63 degrees away from the center of the tab ring and at a position 105 degrees away from the center of the tab ring.

Japanese Utility Model Registration No. 25555616 discloses a metal cap having a circular top surface and a side wall hanging down from the periphery of the top surface, and a tab ring provided on the side wall via a connecting piece. A score is formed along the boundary between the top surface and the side wall from both ends of the connection piece through the side wall, and the score is such that each end point and the center of the top surface are located substantially on a straight line. Are described, and a slit is provided on a side wall on the side where no score is formed near the end point of each score.

[0005]

This type of cap is
Sealing is performed by providing a ring-shaped gasket around the inner surface of the top surface and caulking the lower end of the cap side wall below the bead provided at the mouth of the cup. Also, for ease of opening, the cap shell uses a relatively thin aluminum sheet that is somewhat flexible.

In connection with the sealing structure and the flexibility of the cap shell, when the sealing cup is dropped in an inverted state,
It has been found that there is a problem that the water hammer causes liquid splash. That is, the sealing effect of the contents is not impaired by the drop impact, but the contents liquid jumps out of the container through the sealing portion between the cup and the lid. When such a liquid splash occurs, even if the amount of the liquid is extremely small, mold or the like may be generated in the vicinity of the sealed portion, and it is strongly desired to reduce it from a sanitary viewpoint.

Accordingly, an object of the present invention is to provide an impact-resistant easy-open container lid in which liquid splash due to an inverted drop impact (water hammer) is reduced. Another object of the present invention is to provide an impact-resistant easily-openable container lid having excellent sealing properties and also having a function of easily confirming that the sealing properties are maintained by visual inspection.

[0008]

According to the present invention, a shell having a top surface portion and a short skirt portion, and a sealing gasket housed in a peripheral groove on the inner surface side of the top surface portion are provided. Is provided with an opening grip portion extending radially outward from the lower end thereof, and at least a pair of opening slits or scores extending in the height direction from the lower end at circumferential intervals from both side ends of the grip portion. In the easy-open container lid for decompression sealing, the top surface portion is provided with a portion that can be bent upward and deformed and restored via a circumferential base located inside the inner peripheral edge of the sealing gasket. An easily-openable container lid having impact resistance is provided. In the container lid of the present invention, the shell is formed from aluminum, and the aluminum is 25 kg / m2.
m ² or more, and the upwardly convex portion is
It is preferable to have a property of flipping down under reduced pressure at the time of sealing and having a property of flipping up by opening, and as a typical upwardly convex portion, the pressure difference between the outside of the container and the inside of the container is flipped down at 12 cmHg or more, In addition, a material having a characteristic of flipping up when the pressure difference between the outside of the container and the inside of the container is 8 cmHg or less can be given.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Operation] The container lid according to the present invention comprises a shell having a top surface and a short skirt portion, and a sealing gasket housed in a groove around the inner surface of the top surface portion. Is provided with an opening grip extending radially outward from the lower end thereof and at least a pair of opening start slits or scores extending in the height direction from the lower end at circumferential intervals from both side ends of the gripping portion. However, on the top surface, there is a part (hereinafter, also referred to as a button) that can be bent upward and deformed and restored via a circumferential base located inside the inner peripheral edge of the sealing gasket. The feature is that it is provided. In the present specification, the upwardly deformable portion capable of deforming and restoring is based on a partial spherical shell in terms of material mechanics. Thus, as shown in the examples described later, those having various structural modifications are also used. With this feature, according to the present invention, liquid splash due to an inverted drop impact (water hammer) can be effectively reduced.

See the experimental examples described below. When the above-described easily-openable container lid (Comparative Example 1) except that the above-mentioned convex bending deformation and restorable portion (button) were not provided was subjected to the inverted drop test, the liquid splash According to the present invention, the amount of generated gas reaches 24 mg, and in the easy-open container lid (Example 1) provided with a part (button) capable of bending deformation and restoring upward in the same drop test, The amount of occurrence of jump can be suppressed to 13 mg or less,
The unexpected effects of the present invention become apparent.

In the present invention, it is considered that the provision of an upwardly convex portion capable of deforming and restoring (button) can reduce liquid splash by the water hammer for the following reasons. That is, in this type of packaging container,
In order to improve the storage stability of the contents, the temperature is generally 60
After hot-filling the contents at ~ 90 ° C and tightening the easily-openable container lid, the sealed container is allowed to cool or forcibly cool. Due to this cooling, the inside of the container is 15 to 50 cm below the atmospheric pressure.
The button is in a depressurized state with a low Hg, the button is bent downward, that is, bent toward the container, and the button is kept bent downward as long as the container lid is maintained in a sealed state. When the sealed container is dropped in an inverted state, the impact of the water hammer is applied to the container lid, but this impact deforms the button from the state that the button momentarily bent to the container side to the original outward convex state This absorbs and reduces the impact of the water hammer. By this shock absorption and mitigation, liquid splash from the sealing portion is significantly reduced.

In the easy-open container lid of the present invention, it is also important that the button is provided at a central portion of the inner surface of the top surface inside the inner peripheral edge of the sealing gasket. With this configuration, it is possible to effectively absorb and reduce the impact of the water hammer, and even if the button is vertically deformed, this deformation does not adversely affect the sealing performance of the container lid. It is possible to do so. As actually shown in the examples described below, in the container lid of the present invention, even after the drop impact is applied, the degree of pressure reduction in the container is almost the same as before the drop impact is applied,
Excellent sealing properties are maintained. Of course, on the container lid after the drop impact is applied, the button is in a convexly bent state toward the container side, indicating that the depressurized and sealed state is maintained.

In the present invention, it is desirable that the shell of the container lid is made of aluminum from the viewpoint of easy opening, and this aluminum has a proof stress of 25 kg / mm ² or more, so that the impact of the water hammer can be effectively prevented. Desirable to reduce absorption. The proof stress of aluminum is a stress at a permanent set of 0.2%. When the proof stress is lower than the above range, the liquid leakage due to the water hammer tends to increase rather than in the above range. . This is probably because the higher the proof stress, the more effective it is in absorbing shock.

The upwardly convex portion used in the present invention preferably has a characteristic of flipping down under reduced pressure during sealing and flipping up by opening. Because the impact absorption and mitigation by the water hammer,
This is because it is expressed in a state where the upwardly convex portion is maintained in a state of being bent inward, and in the case of lacking the characteristic of flipping up by opening, for absorbing and relaxing impacts This is because deformation of the hardly occurs.

In the container lid of the present invention, in the reduced pressure sealed state,
Since it is in a flip-down state, it also has a quality assurance function and a tamper-evidence function that the contents can be easily visually checked from the outside of the container that the contents are sealed under reduced pressure.

[0016]

The present invention will be described with reference to the following examples. FIG.
FIG. 2 is a plan view showing an example of the container lid of the present invention, FIG. 2 is a bottom view of the container lid of FIG. 1, and FIG. 3 is a side view of the container lid of FIG. 4 is a side view of the container lid of FIG. 1 viewed from a position rotated 90 degrees from the position of FIG. 3, FIG. 5 is an enlarged side sectional view of the container lid of FIG. 1, and FIG. 6 is a container lid of FIG. 7 is a partially enlarged side view showing the detailed structure of the opening slit of FIG. 7, FIG. 7 is a cross-sectional view showing the container lid in a vacuum-sealed state together with the container mouth, and FIG. 8 is a thin partial sphere in the container lid of FIG. FIG. 9 is an explanatory diagram for explaining the dimensional relationship of the shell, and FIG. 9 is a graph for explaining the relationship between the amount of deflection of the container cover spherical shell and the pressure difference between the inside and outside of the container.

The container lid of the present invention has a metal shell 1 having a top surface portion 11 and a short skirt portion 12 hanging down from the periphery of the top surface portion, and a sealing member housed in a groove 13 around the inner surface side of the top surface portion. And gasket 2. Skirt part 1
2, an opening grip 3 extending radially outward from the lower end thereof, and at least a pair of opening slits or scores extending from the lower end in the height direction at circumferential intervals from both side ends of the grip, In the example, first slits 41, 41 and second slits 42, 42 are provided. These opening slits 41 and 42 are useful for removing the container lid from the container opening.

In the cap of this embodiment, as shown in FIG. 5, the top surface portion 11 has a ring-shaped top surface portion 14 at a small interval from the skirt portion 12, and from the inner peripheral edge of the ring-shaped top surface portion 14. There is a rim portion 15 that is inclined downward in a radially inward and downward direction, and a flat central panel portion 16 is connected to the rim portion 14. Thus, the upper part of the skirt part 12, the ring-shaped top part 14 and the rim part 15
It can be understood that the portion on the inner surface side surrounded by a circle is the gasket storage groove 13.

The opening gripping portion 3 is formed of a resin ring 31 and is fixed to a tongue piece 32 (see FIG. 5) extending from the lower end of the skirt portion 12 so as to be inseparable. At the time of opening, in order to weaken the tightening force of the skirt portion 12 on the container opening 61 (see FIG. 7), the skirt portion 12 extends in the height direction from the base portions 33 on both sides of the holding portion 3 for opening, and the top surface portion. An opening start score 34 is formed which extends a short distance from the periphery of the opening 11 in the direction opposite to the opening gripping portion 3.

On the other hand, the first slit 41 facilitates removal of the portion of the skirt portion 12 on the inner opening gripping portion side from the container opening 61 at the time of opening, while the second slit 42 allows the opening at the time of opening. The portion of the skirt portion 12 behind the second slit (the portion opposite to the opening gripping portion) is easily removed from the container opening 61. Thus, the first slit 41 is formed in the skirt 1
2 is formed on the side of the opening gripper 3 when the opening gripper 2 is divided into the opening gripper 3 and the opposite side, while the second slit 42 is formed on the opposite side of the opening gripper 3. Have been.

In FIG. 6 showing the detailed structure of these slits 41 (42), a notch (notch) 43 is formed at the lower end of the skirt portion 12, and at the deepest portion of the notch. A lower slit 44 is connected, and an upper slit 45 is provided via a bridge 46 so as to be in line with the lower slit 44. The opening operation by the slit will be described later in detail.

In the container lid of the present invention, the central panel portion 16 located inside the inner peripheral edge of the groove 13 has a portion that can be bent upward and deformed and can be restored through a circumferential base portion 17. Button) 5 is provided.

The upwardly convex, deformable and restorable portion 5 is in its simplest form a partial spherical shell,
In FIG. 8 for explaining various dimensions of the partial spherical shell,
The shape and size of the partial spherical shell 5 are determined by its radius of curvature R and half-vertical angle θ (radian). That is, the height H of the partial spherical shell is H = R−Rcos θ = R (1−cos θ), while the projected area (S) of the partial spherical shell in the vertical direction is S = π (Rsin θ) ² . .

On the other hand, in the embodiment shown in FIGS. 1 to 7, the upwardly convex portion 5 which can be deformed and restored has a shape obtained by deforming the partial spherical shell shown in FIG. A ring-shaped rising portion 51 having a smaller width inside the circumferential base portion 17, a frustoconical portion 52 connected to the inner peripheral edge of the ring-shaped rising portion 51, and a flat connected to the inner peripheral edge of the frustoconical portion 52. And a circular portion 53. The inclination angle of the rising portion 51 is larger than the inclination angle of the truncated cone portion, whereby the rising portion 51 itself bends slightly downward under reduced pressure and assists the downward reversal deformation of the truncated cone portion 52. Act like so. The flat circular center portion 53 is provided to impart work hardening to this portion, whereby the circular portion 53 moves up and down above or below a certain fixed pressure while maintaining its shape. It is possible. By making such a deformation possible, for example, it is also possible to generate a sound at the time of opening. Further, a shape in which a slight concave portion is provided between the rising portion 51 and the truncated cone portion 52 is also possible.

The height H of the upwardly convex portion and the projected area S thereof
Has a certain preferable range from the viewpoint of the function of absorbing the impact of the water hammer, the strength and the sealing property of the container lid, and the reversibility and reversibility of the upwardly convex portion. Generally, this height (H) is in the range H = 0.3-0.7 mm, while the area (S) is preferably in the range S = 19.5-38.5 cm ² . If the height (H) is below the above range, the amount of downward bending under reduced pressure sealing is reduced, so that the degree of shock absorption relaxation of the water hammer is reduced, and the liquid splash tends to increase. When (H) exceeds the above range, the mechanical strength and the sealing performance of the container lid tend to be reduced, and the inversion and restoring action of the upwardly convex portion tends not to occur. This is not preferable because sometimes the upwardly convex portion may be deformed or rubbed. Also, the area (S)
When the value is below the above range, the amount of downward bending and deformation volume under reduced pressure sealing is reduced, so that the degree of shock absorption relaxation of the water hammer is reduced, and the liquid splash tends to increase, while the area (S) Is more than the above range, the mechanical strength and sealing performance of the container lid tend to decrease, which is not preferable.

The downward bending amount (δ) of the upwardly convex portion 5 in the container lid of the present invention at the time of pressure-reducing sealing is not only the above-mentioned form factor but also the pressure difference between inside and outside (ΔP) and the elastic modulus of the metal material. (E) and the thickness (t) of the metal material. Ratio of bending amount per metal material thickness in partial spherical shell (δ / t)
And the characteristic value (ΔPR ² / 2Et ² ) proportional to the inside / outside air pressure difference
When Rθ ² / t is 5 or more, the value of ΔPR ² / 2Et ² is a minimum value (Min) in a region where δ / t is somewhat large, as shown by a curve A in FIG. Is known to exist. Among the above characteristic values (ΔPR ² / 2Et ² ), values other than the pressure difference (ΔP) always take a constant value for a constant partial spherical shell, so the curve shown in FIG. 9 shows the relationship between the pressure difference and the deflection. It may be considered to indicate

That is, the flip-down during the depressurized sealing of the container lid of the present invention is a process of generating the bending indicated by the right-pointing arrow B, while the flip-up at the time of depressurizing disappearance is the process of eliminating the bending indicated by the left-pointing arrow C And the deflection is stable near the minimum value.

The ratio (δ / t) of the amount of bending per metal material thickness in the container lid of the present invention is generally 1 in terms of prevention of liquid splash by a water hammer and clarification of vacuum sealing. It is preferably in the range of 0.0 to 5.0, particularly preferably in the range of 1.4 to 4.0. The pressure difference (ΔP) at the time of sealing under reduced pressure is generally 10 to 60 cmH.
g, especially in the range of 15 to 50 cmHg. Thus, so that the above-mentioned deflection amount is satisfied by the above-mentioned pressure difference,
The radius of curvature R and the half apex angle θ (radian) of the partial spherical shell 5 and the elastic modulus (E) and thickness (t) of the metal material forming the partial spherical shell 5 may be determined. Needless to say, even when the partial spherical shell is deformed, the same applies to the case of the partial spherical shell.

In the state of the easily-openable container lid of the present invention, before being closed, as shown best in the enlarged sectional view of FIG. 5, the upwardly convex portion 5 does not protrude from the top surface 14 of the top surface portion. It preferably exists in a range that is convex upward.

Prior to using the easily-openable container lid of the present invention for sealing the container, the inside of the container 6 is filled with the contents 7 in a hot state, for example, at a temperature of 60 to 90 ° C. Immediately after this hot filling, the container lid 1 was placed in the container opening 6.
While pressing at a constant pressure via the gasket 3, caulking the lower end of the skirt portion 12 so that the diameter is reduced,
The caulking portion 18 is engaged with the outer peripheral lower portion 62 of the container opening 61 on the bead. In this sealed container, the inside is decompressed as the contents 7 are cooled, and as a result, the upwardly convex portion 5 becomes a downwardly convexly bent state 55.

In this type of sealed container, when the height of the skirt portion is increased and the area of the caulked portion is increased, the opening force becomes extremely high, and opening becomes difficult. Therefore, in this type of cap, the swaged portion has to be made shallow, so that the liquid splashing phenomenon due to the water hammer is a peculiar phenomenon in this type of cap. In the present invention, FIG.
By permitting the deformation from the recessed state 55 to the protruding state 5 shown in FIG. 5, the amount of liquid splash generated has been significantly suppressed.

The opening operation of the easily-openable container lid of the present invention is performed as follows. First, the ring 31 of the opening gripping portion 3 is held by a finger and pulled toward the user. As a result, the opening start score 34 provided at the base 33 on the both sides of the grip portion 3 or in the vicinity thereof is sheared, and the skirt portion on the grip portion side becomes deformable. Next, when the gripping portion 3 is lifted upward while being held, the bridge 46 of the first opening slit 41 is sheared, and the slit 4 is opened.
The upper surface portion and the skirt portion can be bent or bent upward with the upper edge portion 1 as a fulcrum, and by continuing lifting upward, the second opening slit 42 is opened.
Bridge 46 is sheared, and the top surface and the skirt can be bent or bent upward with the upper edge portion of the slit 42 as a fulcrum.
1 and the opening is completed.

The lid shell of the present invention is preferably made of aluminum. Although the lid shell may be made of pure aluminum, it is generally preferable to use an aluminum alloy from the viewpoints of strength, rigidity, corrosion resistance, etc. In this aluminum, Si, Fe, Cu, M
Alloy metals such as n, Mg, Cr, Ti, and Ni are contained. A preferred aluminum substrate is Cu 0-0.8%, Mg
0 to 2.8%, Mn 0 to 1.5%, Fe 0 to 0.5%, Si 0
組成 0.5% (% by weight), for example, pure aluminum having a metal number of 1070, 1050, 1100, 1200, etc. according to JIS standard (H 4000), 2011, 2014, 2017, 202
Al-Cu based alloys such as No. 4, 3003, 3004, 30
Al-Mn based alloys such as No. 24, 5005, 5052, 5
Al-Mg based alloys such as 154, 5082, alloy number 5
Al-M such as 182, 5056, 5083, 5086
Al-Mg such as n-Mg alloys, 6061 and 6063
-Si-based alloys, Al-Zn-based alloys such as 7075 and 7N01, and the like are preferable. It is desirable that the thickness of the aluminum is generally in the range of 0.15 to 0.21, particularly 0.18 to 0.20.

It is preferable that at least the inner surface of the container lid shell used in the present invention has a protective coating known per se or is laminated with a resin film or the like. As the protective coating, a thermosetting resin paint, for example, phenol-formaldehyde resin, furan-formaldehyde resin, xylene-formaldehyde resin, ketone-formaldehyde resin, urea formaldehyde resin,
Melamine-formaldehyde resin, alkyd resin, unsaturated polyester resin, epoxy resin, bismaleimide resin, triallyl cyanurate resin, thermosetting acrylic resin, silicone resin, oily resin, or thermoplastic resin paint such as vinyl chloride Vinyl acetate copolymer, vinyl chloride-maleic acid copolymer, vinyl chloride-maleic acid-
Examples thereof include a vinyl acetate copolymer, an acrylic polymer, and a saturated polyester resin. These resin coatings may be used alone or in combination of two or more. On the other hand, examples of the protective laminate resin include low-density polyethylene, high-density polyethylene, polypropylene, poly 1-butene, poly 4-methyl-1-pentene or ethylene, propylene, 1-butene, 4-methyl-1-pentene. Polyolefins such as random or block copolymers of α-olefins among each other, ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, ethylene / vinyl compound copolymer such as ethylene / vinyl chloride copolymer, Styrene resins such as polystyrene, acrylonitrile / styrene copolymer, ABS, α-methylstyrene / styrene copolymer, polyvinyl chloride, polyvinylidene chloride, vinyl chloride / vinylidene chloride copolymer, polymethyl acrylate, polymethacryl Polyvinyl compounds such as methyl acid, Nylon 6, Nylon 6-6, Nylon 6
Resins of any of polyamides such as 10, nylon 11, and nylon 12, thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonates, and mixtures thereof. Suitably, the thickness of the protective coating or film is generally in the range of 4 to 8 μm.

The container lid shell used in the present invention can be manufactured by any method known per se except that a convexly deformable and restorable portion is formed at the center of the top surface. For example, a painted or laminated aluminum plate is press-formed into the shape of the top surface and the skirt shown in the figure, the above-described score or slit processing is performed, and a grip ring is formed integrally with the shell by compression molding or injection molding of resin. Just do it.

The material constituting the gasket is a resin or rubber known per se having cushioning properties and flexibility required for sealing, especially soft vinyl chloride resin, acrylic elastomer, low density polyethylene, ethylene-vinyl acetate. Polymers, thermoplastic polyolefin-based elastomers,
Thermoplastic styrene elastomers such as thermoplastic styrene-butadiene-styrene block copolymer and thermoplastic styrene-isoprene-styrene copolymer, ethylene-propylene rubber, ethylene-propylene-non-conjugated diene rubber, styrene-butadiene・ Rubber, nitrile
Butadiene rubber, butyl rubber, natural rubber, polybutadiene, chloroprene rubber, polyurethane, acrylic rubber, silicone rubber, and the like. Of these, low-density polyethylene, ethylene / propylene copolymer rubber, plastisol of vinyl chloride resin, acrylic plastisol, styrene-butadiene rubber (SBR), especially solvent type SBR, etc. are excellent in sealability and processability, so they are containers. Suitable for liners. These can be used alone or, if necessary, in combination of two or more kinds. In these resins or elastomers, a resin compounding agent known per se, for example, a plasticizer, a filler, a colorant, a heat stabilizer, a foaming agent, a crosslinking agent, and the like can be compounded according to a formulation known per se. . The gasket can be molded, for example, by injection molding, compression molding, or by applying a resin or elastomer melt or plastisol to the inside of the container lid and pressing it as needed to form a liner.

The following experimental examples are shown to specifically show the effects of the present invention. [Experimental Examples] 1) Preparation of Container Lid An aluminum material shown in Table 1 was pressed with a press die to form an easily-openable container lid shell shown in FIG.

2) Evaluation of Cap Performance A one-cup glass bottle for sake was heated at 70 ° C. for 200 m.
After filling, the container lid shown in Table 1 was capped with a Sakaguchi-type crown stopper and allowed to cool naturally. Then, the container was inverted and dropped from a height of 50 cm onto a steel pole having a 15 ° inclination angle, and brought to room temperature for 24 hours. After standing, reduce the pressure in the container with a vacuum cantester.
Was measured. After the natural cooling, the reduced pressure value in the container was measured in the same manner, although the container did not fall down. The weight of the filled product was measured before and after the container was inverted and the difference was defined as the amount of liquid splash mg. The inside of the container was depressurized by a vacuum pump, and the depressurized value when the convex portion above Comparative Example 2 and Example 1 was depressed toward the container was defined as a flip-down value cmHg. Further, the reduced pressure value in the container was released, and the reduced pressure value at the time of restoring the partially convex shape above Comparative Example 2 and Example 1 was defined as a flip-up value cmHg.

3) Evaluation of Cap Performance In Comparative Example 2, the upwardly projecting portion flipped down due to depressurization in the container, but no flip-up occurred when the depressurization was released. There was no difference. On the other hand, in Example 1, the upwardly projecting portion flipped down due to the reduced pressure in the container, and flipped up when the reduced pressure was released. Furthermore, the amount of liquid splashing when the container was inverted was clearly lower than in Comparative Examples 1 and 2.

[0040]

[Table 1]

[0041]

The container lid of the present invention comprises a shell having a top surface and a short skirt portion, and a sealing gasket housed in a peripheral groove on the inner surface side of the top surface portion. An opening grip portion extending radially outward from the lower end and at least a pair of opening start slits or scores extending in the height direction from the lower end at intervals in the circumferential direction from both side ends of the grip portion are provided, The top surface is provided with a portion (button) that is upwardly convex and can be deformed and restored via a circumferential base located inside the inner peripheral edge of the sealing gasket. In addition, it is possible to remarkably reduce liquid splash caused by an inverted drop impact (water hammer). That is, the present invention is applied to a container in which the contents are sealed in a reduced pressure state. In this state, the upwardly convex portion is maintained in a downwardly bent state. When the sealed container is dropped in an inverted state, the impact of the water hammer is applied to the container lid, but this impact restores the button from the state that the button bent to the container side to the original outward convex state. This absorbs and reduces the impact of the water hammer. Due to this shock absorption and mitigation, liquid splash from the sealed portion is significantly reduced. In the container lid of the present invention, in the depressurized sealed state, since it is in a depressed and bent state, it can be easily visually confirmed from outside the container that the contents are sealed in the depressurized state. It also has a quality assurance function and a tamper evidence function.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a container lid of the present invention.

FIG. 2 is a bottom view of the container lid of FIG.

FIG. 3 is a side view of the container lid of FIG. 1 as viewed from the side of an opening grip.

FIG. 4 is a side view of the container lid of FIG. 1 as viewed from a position rotated 90 degrees from the position of FIG. 3;

FIG. 5 is an enlarged side sectional view of the container lid of FIG. 1;

FIG. 6 is a partially enlarged side view showing a detailed structure of an opening slit of the container lid of FIG. 1;

FIG. 7 is a cross-sectional view showing a container lid in a reduced pressure sealed state together with a container mouth.

FIG. 8 is an explanatory diagram illustrating a dimensional relationship when an upwardly convex portion is a partial spherical shell.

FIG. 9 is a graph for explaining the relationship between the amount of deflection of the partial spherical shell of the container lid and the pressure difference between the inside and outside of the container.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Ryuichi Tsukamoto, Inventor 2-12 Nagatoro, Hiratsuka-shi, Kanagawa Japan Inside the Hiratsuka Plant, Japan (72) Inventor Hiroaki Kikuchi 2-12 Nagatoro, Hiratsuka-shi, Kanagawa Japan, Japan Inside the Hiratsuka Plant Co., Ltd. (72) Inventor Takeshi Fukui 180, Oji-shimotsu, Komaki City, Aichi Prefecture Japan Crown Cork Co., Ltd. F-term (reference) at Komaki Plant, Crown Cork Co., Ltd. 3E084 AA02 AA12 AA32 AB02 BA01 CA01 CC02 DA01 DB01 DB09 DC02 FA09 FD08 GA08 GB08 GB12 GB17 HA03 HB03 HC03 HD01 LA03 LA17

Claims (5)

[Claims] 1. A shell having a top surface portion and a short skirt portion, and a sealing gasket housed in a peripheral groove on an inner surface side of the top surface portion, wherein the skirt portion extends radially outward from a lower end thereof. In the depressurized sealing easy-open container lid provided with at least a pair of opening start slits or scores extending in the height direction from the lower end at intervals in the circumferential direction from the opening grip portion and both side ends of the grip portion. Wherein the top surface is provided with an upwardly convex portion capable of being deformed and restored via a circumferential base located inside the inner peripheral edge of the sealing gasket. Easy-opening container lid with the property. 2. The container lid shell is made of aluminum, the aluminum having a proof stress of 25 kg / mm ² or more, and the upwardly convex portion flips down under reduced pressure during sealing and is opened. 2. The easily-openable container lid according to claim 1, wherein the container lid has a characteristic of flipping up. 3. The upwardly convex portion has a property of flipping down when the pressure difference between the outside of the container and the inside of the container is 12 cmHg or more and flipping up when the pressure difference between the outside of the container and the inside of the container is 8 cmHg or less. The easy-open container lid according to claim 1 or 2, wherein 4. A top surface portion having a ring-shaped outer peripheral side top surface portion,
A rim portion hanging downward from the inner periphery of the top surface portion, and a flat central panel portion connected to a lower side of the rim portion, and a convex portion is formed on the central panel portion. The easy-open container lid according to any one of claims 1 to 3, characterized in that: 5. The height H and the projected area S of the upwardly convex portion are such that the height (H) is in the range of 0.3 to 0.7 mm,
And the easy-open container lid of claim 4, the area (S) is being in the range of 19.5~38.5cm ^2.