JPS62122956A - Vessel cover made of olefin group resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an olefin resin container lid having pilfer-proof properties. More specifically, the container is made of olefin resin having pilfer-proof properties for a container having a mouth and neck part in which a male thread and a locking jaw part located below the male thread are formed on the outer peripheral surface. This relates to container lids.

The bridge portion at the weakened line is reliably prevented from breaking when the container lid is attached to the mouth and neck of the container, and the bridge portion at the weakened line is easily and securely broken when the container lid is removed. The object of the present invention is to provide an improved olefin-based resin container lid that can ensure the following.

In recent years, synthetic resin container lids have been proposed in place of metal container lids as pilfer-proof container lids for containers such as beverage and food bottles, and have come into practical use. It has become. Such a synthetic resin container lid includes a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall. A weakened line consisting of a plurality of slits extending in the circumferential direction at intervals in the circumferential direction and a plurality of bridges existing between the slits is formed in the skirt wall, and the skirt wall is formed along the weakened line. It is divided into an upper main part and a pilfer-proof hem part below this weakened line. A female thread is formed on the inner surface of the main portion, and a plurality of locking means are formed on the inner surface of the pilfer-proof hem.

The above-mentioned container lid is applied to a container having a neck portion in which a male thread and a locking jaw portion located below the male thread are formed on the outer peripheral surface. When closing the mouth and neck of a container with a container lid, the container lid is fitted onto the mouth and neck and rotated in a predetermined direction, that is, the closing direction, so that the female thread on the container lid is connected to the male thread on the mouth and neck. Screw together. In this way, the container lid is lowered as it rotates, and the locking means of the container lid is sexually displaced or deformed and passes through the locking jaws of the mouth and neck, and then elastically restores and locks. It is engaged with the lower surface of the stop jaw. When opening the mouth and neck of the container, the container lid is rotated in the opposite direction, that is, in the opening direction. In this way, the female thread of the container lid is moved along the male thread of the mouth and neck, and the container lid is therefore raised as it rotates. However, the pilfer-proof hem cannot rise because the locking means formed on its inner surface are engaged with the lower surface of the locking jaws of the mouth and neck, and therefore, the locking means formed on the skirt wall cannot rise. Significant stress is created in the bridge at the weakened line, which ruptures and separates the pilfer-proof skirt from the main portion. In this way, the container lid is removed from the mouth and neck leaving the pilfer-proof hem, and the mouth and neck are opened.

The conventional synthetic resin container lids described above have various problems as described below. That is, regarding conventional synthetic resin container lids, when the container lid is attached to the mouth and neck of the container, more specifically, when the locking means of the container lid is passed through the locking jaws of the mouth and neck, the container lid is attached to the mouth and neck of the container. It is necessary to apply a considerable rotational torque to the lid, thereby creating significant stresses in the bridge at the line of weakness of the container lid. This causes the bridge to break considerably.

In order to solve this problem, it may be possible to increase the strength at the weakened line, but this would require applying a fairly large rotational torque to the container lid when it is removed from the container. , it becomes extremely difficult for the mouth and neck of the container to separate from the container lid. In addition, in order to solve these problems, it is possible to reduce the amount of radial protrusion of the locking means of the container lid. The retention of the means becomes insufficient, and when the container lid is removed from the mouth and neck, the engagement between the locking jaw and the locking means is released without breaking the bridge at the weakened line. There is a tendency for the container lid to become detached from the container, thus destroying the pilfer-proof properties.

JP 80-158049 and JP 60-18335
In the case of a lid having a locking means consisting only of an annular protrusion or a plurality of protrusions as seen in the specifications of each publication of No. 5, the weakened line is prevented from breaking when the cap is closed, and the weakened line is prevented from breaking when the cap is opened. It is very difficult to guarantee any reliable rupture. That is, if the amount of axial protrusion of the locking means is too large, reliable breakage is achieved when the cap is opened, but the weakened line is likely to break when the cap is opened. On the other hand, if the amount of axial protrusion of the locking means is too small, there will be no problem in preventing the weakened line from breaking when the bottle is opened, but the weakened line will not break completely when the bottle is opened.

I'm going to write it. HigashiFrom the above, the present invention does not have these problems (disadvantages), that is, it not only avoids the breakage of the bridge in the weakened line when attaching the container lid to the mouth and neck of the container, but also prevents the container from breaking. To obtain a synthetic resin container lid having an improved pilfer-proof property so that the bridging portion at the weakened line is easily broken when the container lid is removed from the mouth and neck of a person, and can be reliably guaranteed. It is.

According to the present invention, these problems can be solved by having a mouth and neck part in which a male thread and a locking jaw part located below the female thread are formed on the outer peripheral surface. This is an olefin-based resin container lid for a container, comprising a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, and the skirt wall has a cylindrical skirt wall arranged at intervals in the circumferential direction. A weakened line is formed by a plurality of slits extending in the direction of the slit and a plurality of bridges existing between the slits, and the skirt 11 has a main portion above the weakened line and a pilfer below the weakened line. A female thread is formed on the inner surface of the main portion to be screwed together with a male thread on the pilfer-proof hem. In the container lid in which an annular protrusion is formed to be engaged with the locking jaw, at least two flap pieces are formed at one end of the annular protrusion at equal intervals when viewed in the circumferential direction. The solution can be solved by a container lid made of olefin resin, which is characterized by the fact that it is made of olefin resin. The present invention will be explained in detail below.

The olefin resin used in the present invention is widely produced industrially and used in many fields, and its production method and various physical properties are well known.

Typical examples of this olefin resin include ethylene homopolymers and ethylene-based resins (at least 8
0% by weight) α-olefin type (generally has 3 to 1 carbon atoms)
(hereinafter referred to as "ethylene-based polymers") as well as propylene homopolymers and propylene-based copolymers (at least 80% by weight) of ethylene or other α-olefins (generally carbon The density of the ethylene polymer is usually 0.935 g/cm" or more, and the density of the ethylene polymer is usually 0.935 g/cm" or more. , 0.935-0.955 g/cm
'' is preferable, especially 0.940 to 0.955 g/
crn" is preferred. Density is 0.935g/cm"
If less than 100% of the ethylene polymer is used, the resulting container lid will have low rigidity, and when used as a lid for a carbonated beverage container, there will be problems with pressure resistance. On the other hand, 0.955 g/c
If an ethylene polymer exceeding rn' is used, the environmental stress cracking resistance of the resulting container lid will be poor, and the melt flow index (measured under 1 condition 4 according to JIS K7210, hereinafter referred to as 1. J) is generally 0.1 to 10 g/10 minutes, and 0.2 to 1
0 g / 1 G is desirable, especially 0.5 to 5 g
/lo minutes is preferred, M, 1. If an ethylene polymer with a content of less than 0.1 g/lO is used, the moldability will not be good when manufacturing container lids.On the other hand, if an ethylene polymer with a content of more than 10 g/lO is used, the resultant container lid will have poor formability. Poor environmental stress cracking resistance.

Furthermore, the melt flow rate of propylene polymer (
1 condition according to JIS K7210! 4, hereinafter referred to as r MFRJ) is usually 0.5 to 30 g/10
minutes, preferably 0.5 to 20 g/10 minutes, and preferably 1.0 to 20 g/10 minutes. MFR
If a propylene polymer with a weight of less than 0.5g710 minutes is used, moldability will be poor when manufacturing container lids.
On the other hand, if a propylene-based polymer exceeding 30 g and 710 minutes is used, the resulting container lid will have low impact strength.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific example of an improved olefin resin container lid according to the present invention will be described in more detail with reference to the accompanying drawings.

The three lids of the container shown in Figure 1 (the left half is a cross-sectional view, the right half is a side view) use the above ethylene polymer or propylene polymer, and are commonly used in the field of these olefin resins. It can be obtained by compression or injection molding under these common molding conditions.

The entire lid body 1 includes a circular top wall 2 and a cylindrical skirt hanging from the periphery of the top wall 2! S! 3. A sealing ring 5 is formed on the inner surface of the top wall 2, and an annular protrusion 4 is formed on the inner surface of the skirt wall 3, which provide sealing properties to the container lid, so there is no need to insert a liner material. .

A weakened line 6 extending in the circumferential direction is formed in the skirt wall 3, and the skirt wall 3 is divided into a main portion 7 above the weakened line 6 and a pilfer-proof hem 8 below the weakened line 6. There is. The weakened line 6 itself is formed by a plurality of (six in the illustrated case) slits 9 extending in the circumferential direction at intervals in the circumferential direction and a plurality of (six in the illustrated case) bridge portions 10 located between the slits 9. The pilfer-proof hem portion 8 is connected to the main portion 7 by a plurality of bridge portions IO. Such weakened lines 6 can be formed when forming the lid body 1, or can be formed by cutting the slits 9 after forming the lid body 1.

Advantageously, the outer surface of the main portion 7 of the skirt 3 is provided with a concave-convex shape or a knurled shape 11 to prevent fingers from slipping thereon.

A female thread 12 is formed on the inner surface of the main portion 7 of the skirt wall. A locking means 13 is formed on the inner surface of the pilfer-proof hem 8, which is advantageously thinner than the main portion 7. In the embodiment shown, the locking means 13 are continuous in the circumferential direction. Extending annular protrusion 13-A and annular protrusion 1
It is comprised of a flap piece 13-B that gradually protrudes radially inward from the upper end of 3-A. Referring to FIG. 2 together with FIG. 1, it has an upper portion 14 that gradually projects downward in the axial direction and radially inward, and a lower portion 15 that gradually retreats downward in the axial direction and radially outward. However, it is advantageous that the boundary area between the upper portion 14 and the lower portion 15 is rounded, and the overall shape is smooth without any corners. Advantageously, the angle of inclination α of the upper part 14 with respect to the inner surface of the pilfer-proof hem 8 is between 60 and 80 degrees;
Advantageously, the angle of inclination β of the lower part 15 with respect to the inner surface of the pilfer-proof skirt 8 is between 10 and 60 degrees.

In the container lid improved in accordance with the present invention, the flap pieces 13-B projecting radially inward from the upper end of the annular protrusion 13-A of the locking means 13 are arranged at equal intervals when viewed in the circumferential direction. In the illustrated example, it is important that at least two ribs are formed at the upper end of the annular protrusion 13-A of the locking means 13 between the bridge portions 10 when viewed in the circumferential direction. A plurality of (six in the illustrated case) flap pieces 13-B are formed, each located in the middle. Of course, instead of forming the flap piece 13-B at the upper end of the annular protrusion 13-A of the locking means 13 between each of the bridge parts 10, for example, one flap piece 13-B is formed at the bridge part.
-B can be formed, or a flap piece 13-B can be formed continuously over the entire circumference when viewed in the circumferential direction (in this case, it becomes an annular protrusion 13-B).

The container lid as described above has a form as shown in FIG. An engaging jaw portion 18 is formed below this male thread 17.

When the container lid is attached to the mouth and neck part 16 to close the mouth and neck part 16, the container lid is fitted onto the mouth and neck part 16 and rotated in the closing direction, that is, clockwise when viewed from above in FIG. In this way, connect the female thread 12 of the container lid to the male thread 17 of the mouth and neck part 16.
Screw together. In this way, the container lid is moved downward as it rotates, and at this time, the locking means 13 of the container lid is elastically displaced or deformed, and the locking jaws 1 of the mouth and neck portion 16 are elastically displaced or deformed.
Get over 8. When the female thread 12 is fully screwed into the male thread 17, the locking means 13 completely passes through the locking jaw 18 and is elastically restored as shown in FIG. It engages below the locking jaw 18. In this way, when the locking means 13 passes over the locking jaws 18, a force acts on the pilfer-proof hem 8 to expand it in the radial direction. -B exists and is easily elastically deformed as shown in FIG. Breaking of the connecting portion 10 is reliably avoided.

To unseal the mouth and neck portion 16, the container lid is rotated in the opposite direction, that is, counterclockwise when viewed from above in FIG. In this way, the female thread 12 of the container lid can be attached to the mouth neck part 16.
The container lid is rotated and moved upward in order to move along the male thread 17 of the container lid. However, the pilfer-proof hem 8 has a flap piece 13 formed on its inner surface.
-B is shown in FIG. 3B, the annular protrusion 13-
It overlaps with A, and the amount of protrusion of the annular protrusion is actually increased, and the pilfer-proof hem 8 is securely engaged with the lower surface of the locking jaw 18 and cannot move upward, thus forming the 1 weakened line. Considerable stress is generated in the bridge portion 10 of No. 6, which ensures that the bridge portion 10 is ruptured. After the bridging portion lO is broken and the pilfer-proof hem 8 of the skirt wall 3 is separated from the main portion 7 of the skirt a, the portion of the container lid other than the pilfer-proof hem 8 rotates upward. It is moved and separated from the mouth and neck part 16, and the mouth and neck part 16 is opened in this way. The pilfer-proof hem 8 remains on the mouth and neck region 16. In order to ensure that the pilfer-proof hem part 8 falls below the locking jaw part 18 and to improve the pilfer-proof property, as shown in FIG. 16 and the pilfer-proof hem 8 may be made as large as possible.

As mentioned above, in the specific example shown in the drawings,
When opening the neck part 16, all the bridging parts 1O are broken and the pilfer-proof hem 8 is completely separated from the main part 7 of the skirt wall 3, so that the pilfer-proof hem 8 is separated from the mouth and neck. If desired, one or more of the bridging parts 10 may be strengthened and the pilfer-proof hem 8 may be axially extending at least 1
The weakened lines formed in the pilfer-proof hem 8 are formed on the pilfer-proof hem 8 when the neck 16 is opened. ruptured, the pilfer-proof hem 8 is changed from an endless annular shape to a right-end band shape, which causes the locking means 13 to disengage from the locking jaws 18, and also causes one of the bridging portions 1O to become rigid. or 2
In this way, the entire container lid including the pilfer-proof hem 8 can be maintained without being broken into more than one piece, allowing the neck 16 to be removed.

- And hereafter, the invention will be explained in more detail with reference to Examples. Ten container lids were molded in the configuration shown. In the molded container lid, the female thread inner diameter d = 25.6 mm, outer diameter D = 30.0 mm,
Total height H = 20.5111 m, pill 7 hoop-proof hem height hl = 4.5 ts.

Pilfer-proof hem thickness t l = 1.5 mar,
Radial protrusion amount p of the locking means = Q, 5 mm, upper inclination angle α of the locking means = 70 degrees, lower inclination angle β of the locking means = 1
5 degrees, Width in the bridging direction of the Tachibana connection part W1 construction 1. Oam, radial thickness of the bridging portion E2=0.5I1m, height of the bridging portion h2=0.
It was 5■. And flap single width W 2 =2−
Oam, fluff piece thickness t3=0.5111. The total protrusion of the flap piece was = 1.0 ts intestine.

Ten such container lids were attached to the mouth and neck of a glass container with a nominal diameter of 28 mm in the form shown in FIG. 4, and the required rotational torque was measured. Roughly, it was examined whether the bridging portion was broken properly when the container lid was removed from the mouth and neck. The required rotational torque for the device was 11 to 13 kg-crs, and all the bridges were broken when removed.

Comparative Example Ten container lids were molded which were the same as in the example except that the flap piece 13-B was not present.

Regarding the 10 container lids formed in this way, the necessary rotational torque was measured when they were attached to the mouth and neck in the same manner as in the example, and the bridging portions were successfully broken when removed from the mouth and neck. We tested whether or not.

The required rotational torque for the device is IO or 12Kg -cr
However, no breakage was observed in any of the bridge sections at the time of separation.

From the results of the above Examples and Comparative Examples, it is clear that the container lid of the present invention maintains good rupture at the bridging portion when detached from the mouth and neck of the container, and therefore does not damage the pilfer-proof property. It is clear that it is possible to considerably reduce the required rotational torque when applying a container lid to the neck, thereby reliably avoiding breakage of the bridge when applying a container lid to the mouth and neck. be.

The olefin resin container lid of the present invention exhibits the following effects (features).

(1) Breakage of the bridge portion can be reliably avoided when the cap is closed.

(2) When opening the bottle, the bridge can be reliably broken (
Very good pilfer proof).

(3) Very good sealing performance (no liner material required).

(4) Since it is linerless, it is very advantageous in terms of manufacturing cost.

(5) It is very easy to open.

(a) The outer surface of the skirt can be knurled.

(b) The strength of the bridge portion can be weakened.

[Brief explanation of drawings]

FIG. 1 is a side view showing a part of a specific example of the container lid of the present invention in cross section, and FIG. 2 is a partially enlarged view showing the shape of the locking means in the container lid shown in FIG. 1. FIG. Moreover, FIG. 3A is a schematic diagram of the deformed state of the flap 13-H when the cap is closed, and FIG. 3B is a schematic diagram of the deformed state of the flap piece 13-H when the cap is opened. Further, FIG. 3C is a conceptual diagram of a preferred example of a pilfer-proof hem. Furthermore, FIG. 4 is a partial cross-sectional view of the container lid shown in FIG. 1 in a state where it is attached to the mouth and neck of the container. l...Container lid body, 2...Top wall 3...Skirt wall, 4...Annular protrusion 5...Sealing ring , 6...Weakening line 7...Main part of skirt wall 8...Pilfur proof hem 9...
Slit, 10...Bridging portion 11...
...notch, 12...female thread. 13...Locking means, 13-A...
Annular protrusion 13-B...flap piece, 16...mouth neck of container, 17...male thread 18...locking jaw part

Claims (2)

[Claims] (1) An olefin-based resin container lid for a container having a mouth and neck part in which a male thread and a locking jaw part located below the male thread are formed on the outer peripheral surface, It comprises a face wall and a cylindrical skirt wall hanging down from the periphery of the top wall, and the skirt wall has a plurality of slits extending in the circumferential direction at intervals in the circumferential direction and a plurality of slits existing between the slits. The skirt wall is divided into a main part above the weakened line and a pilfer-proof hem below the weakened line. is formed with a female thread that is screwed into the male thread on the mouth and neck, and an annular protrusion is formed on the inner surface of the pilfer-proof hem that is engaged with the locking jaw on the mouth and neck. 1. A container lid made of olefin resin, characterized in that at least two flap pieces are formed at the upper end of the annular protrusion at equal intervals when viewed in the circumferential direction. (2) The olefin resin container lid according to claim 1, wherein the amount of protrusion of the annular protrusion is smaller than the amount of protrusion of the flap piece.