JPH11100054A - Synthetic resin cap and closing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superior low cost synthetic resin cap and a closing device in which a sealing closed state can be kept even with a container which causes a phenomenon of falling of a bottle mouth. SOLUTION: A synthetic resin cap 1 is comprised of a cap main body 4 including a top plate 2 and a cylindrical part 3 suspended from a circumferential edge of the top plate. In this case, the cylindrical part 3 is divided by a weakening line 7 into a major part 8 higher than the weakening line and a lower TE ring 9. The inner wall surface of the major part 8 is formed with a threaded part 10 and the inner wall surface of the TE ring is provided with a plurality of engaging protrusions 11 which can be corrugated. An annular resilient protrusion 12 extending in a downward direction and an annular sealing protrusion 13 extending from an inner wall surface of the cylindrical part lower than the resilient protrusion with its extremity end being directed toward an inward diameter direction and having at least its extremity end of resiliency are arranged integrally with the top plate at any one of the positions ranging form a circumferential edge of the top plate to an upper end of the cylindrical part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap made of synthetic resin having tamper-evidence and a closing device using the same.

[0002]

2. Description of the Related Art In recent years, a synthetic resin container (PET bottle) made of polyethylene terephthalate resin has been awarded as a beverage container. The synthetic resin container has excellent characteristics that it is lighter and does not break as compared with a conventional glass bottle. In addition, as a cap for this type of synthetic resin container, a metal cap such as an aluminum alloy has conventionally been used. The use of a synthetic resin cap instead of this type of metal cap is being studied. This synthetic resin cap is disclosed in, for example, JP-A-62-2513.
No. 52, JP-A-2-296666 are known. These conventional synthetic resin caps have a male screw formed at the mouth and are screwed into a container having an annular bulge formed below the male screw.
The cap body is made of a synthetic resin cap body composed of a top plate part and a cylindrical part hanging down from the periphery thereof, and a thin liner provided on the inner surface of the top plate part of the cap body. A horizontal score formed in the circumferential direction leaving a plurality of narrow bridges divides the main portion above the horizontal score and a tamper evidence ring portion below the horizontal score. The inner wall surface of the main part of the cap body has a threaded part that is screwed to the external thread of the container mouth, and the inner wall surface of the tamper evidence ring has a number of wings and tabs (locking projections) that can be raised and lowered. Is provided. Further, as the container, one having a male screw formed on the outer periphery of the upper end portion of the mouth portion and an annular bulging portion (locking ring) provided below the male screw is used.

[0003]

In a conventional synthetic resin cap, a cap body is manufactured using a relatively hard resin such as polypropylene, and then a soft resin is applied to the inner surface of the top plate to form a liner. Therefore, there is a problem that the cost is increased because the material and the processing cost are required. Another problem is that when a container made of synthetic resin such as a PET bottle is rapidly cooled from a high-temperature state to a low-temperature state, such as when it is filled with a heated liquid, the upper end of the mouth shrinks in diameter and the upper end in the radial direction. There is a case where a phenomenon of falling inward (hereinafter, referred to as a bottle opening phenomenon) may occur. When this phenomenon occurs, the conventional liner cap has a problem that the sealing performance is easily deteriorated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an excellent synthetic resin cap and a closing device which are inexpensive and can maintain the sealing property even in a container in which a bottle opening phenomenon occurs. And

[0005]

According to the present invention, there is provided a synthetic resin cap having a cap body comprising a top plate and a tube hanging down from the periphery of the cap, wherein the tube is provided with a weakening line. An upper main portion and a lower tamper evidence ring portion are partitioned, a screw portion is formed on an inner wall surface of the main portion, and a plurality of undulating projections are provided on the inner wall surface of the tamper evidence ring portion. In the synthetic resin cap, an annular resilient projection extending downward to any position from the periphery of the top plate portion to the upper end portion of the cylindrical portion,
A tip is extended radially inward from the inner wall surface of the cylindrical portion below the resilient projection, and at least a tip has a flexible annular seal projection provided integrally with the top plate portion. It becomes.

The closing device according to the present invention includes a cap body including a top plate portion and a tubular portion hanging down from the periphery thereof, and the tubular portion is cut by a weakening line, and is connected to a main portion above the weakening line. A synthetic resin which is partitioned into a lower tamper-evidence ring portion, a screw portion is formed on an inner wall surface of the main portion, and a plurality of undulating locking projections protruding from the inner wall surface of the tamper-evidence ring portion. A male screw is formed on the outer periphery of the upper end of the mouth portion, and a closing device including a container having an annular bulge formed below the male screw, wherein the synthetic resin cap is An annular resilient projection extending downward to any position from the periphery of the top plate to the upper end of the cylinder, and a tip extending radially inward from the inner wall surface of the cylinder below the resilient projection Out, at least the tip is flexible An annular seal projection having the same is provided integrally with the top plate part, and when the synthetic resin cap is attached to the container mouth, the seal projection abuts on the container mouth and bends to form a resilient projection. It is characterized in that it is configured to be pressed radially outward. In this closing device, the synthetic resin cap is provided with a plate-shaped undulating tab as a locking projection, and the container is provided with the synthetic resin cap attached to the bulging portion at the container opening. When turning in the cap opening direction, a pressing part having an inclined surface that gradually bulges downward in the cap opening direction may be formed, engaging with the tab of the cap and pushing down the tab. . Further, the pressing portion may be provided with an extended step portion that engages with the tab pressed down by the inclined surface and prevents the tab from moving upward. Further, it is preferable that the side of the extension step portion opposite to the inclined surface is a storage guide surface that gradually reduces the protruding height in the cap opening direction. In the closing device of the present invention, it is desirable that the cap attached to the container opening is rotated in the opening direction and the bridge cutting angle, which is the rotation angle up to the position where the bridge is cut, is 90 degrees or less.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A synthetic resin cap (hereinafter referred to as a cap) and a closing device using the same according to the present invention are described below.
An annular resilient projection extending downward to any position from the periphery of the top plate of the cap to the upper end of the cylindrical portion, and a tip directed radially inward from the inner wall surface of the cylindrical portion below the elastic projection. An annular seal protrusion extending at least at the distal end is provided integrally with the top plate, and when the cap is attached to the container mouth, the seal protrusion abuts on the container mouth to bend. Since the resilient projection is configured to be pressed outward in the radial direction, a low-cost linerless cap can be provided without applying another liner material to the cap body.
Further, in a state where the cap is attached to the container mouth, the container mouth is sealed in a state where the sealing projection is pressed against the upper end of the container mouth by the elastic force of the resilient projection, so that the sealing can be reliably performed. . Furthermore, when a bottle mouth falling phenomenon in which the upper end of the container mouth falls down in the radial direction occurs, the fall can be compensated for by the elastic projection returning radially inward,
Even when the bottle mouth collapse phenomenon occurs, it is possible to maintain good sealing performance. Further, in the closing device of the present invention, when the cap attached to the container mouth is turned in the opening direction in the bulging portion of the container, the tab engages with the tab (locking projection) of the cap to engage it. A configuration in which a pressing portion having an inclined surface that gradually bulges downward in the cap opening direction is formed, or the pressing portion is engaged with a tab pressed down by the inclined surface to push upward. An extension step for preventing movement is continuously provided, and preferably, a storage guide is formed on the opposite side of the inclined surface of the extension step to gradually reduce the protruding height in the cap opening direction, thereby opening the cap. At this time, the locking projection of the cap comes into contact with the pressing portion of the container mouth portion and is pressed down, whereby the tamper evidence ring portion (hereinafter referred to as TE ring portion) is also pressed down, so that it rises along the external thread of the container. With the main part E ring portion and is rapidly separated from each other,
Since the weakening line connecting the main portion and the TE ring portion is broken, the bridge cutting angle (BBA) can be set to 90 degrees or less.

FIGS. 1 to 4 show an example of a cap and a closing device according to the present invention. This closing device comprises a cap 1 and a container 21. The cap 1 includes a top plate portion 2 and a cylindrical portion 3 hanging down from the periphery thereof, and includes only a cap body 4 made of a synthetic resin such as polypropylene. The cylindrical portion 3 of the cap body 4
By a horizontal score 7 (a weakened line) obtained by cutting the cylindrical portion 3 along the circumferential direction while leaving a plurality of narrow bridges 6,
The horizontal score 7 is divided into a main part 8 above and a tamper evidence ring part 9 (hereinafter referred to as a TE ring part) below. A screw portion 10 is formed on an inner wall surface of the main portion 8, and a large number of plate-like tabs 11 serving as locking projections are provided on the inner wall surface of the TE ring portion 9 so as to be able to undulate. Note that an annular bead may be formed immediately below the base end of the tab 11 so as to protrude radially inward to prevent the tip of the tab 11 from falling down. The TE ring 9 may be formed with a vertical weakening line that is cut almost simultaneously with the cutting of the horizontal score 7 to open the TE ring 9 in a band shape.

When the tab 11 is not mounted on the container, its tip is substantially horizontal with its tip directed radially inward. When the cap 1 is mounted on the container opening 21A, the male screw 22 or the annular shape is used. When it comes into contact with the bulging portion 23, the upper end is folded upward, so that the male screw 22 and the annular bulging portion 23 can be climbed over with almost no resistance. In the cap 1 of the present embodiment, twelve tabs 11 are arranged on the inner peripheral surface of the TE ring portion 9.

An annular elastic projection 12 extending downward is provided at a boundary portion from the peripheral edge of the top plate 2 to the upper end of the cylindrical portion 3, and extends from the inner wall surface of the cylindrical portion 3 below the elastic projection 12. Has a distal end extending radially inward, and at least a distal end is provided with a flexible annular seal projection 13. These resilient projections 12 and seal projections 13 are provided integrally with the cap body 4. When the cap 1 is attached to the container opening 21A, the sealing protrusion 13 is attached to the container opening 2A.
1A, it bends and presses the resilient projection 12 radially outward.

The dimensions of the cap 1 are not particularly limited, but the preferred range of each dimension for a general-purpose cap is as follows. The protruding length of the tab 11 from the inner wall surface of the TE ring portion 9 is 1.5 to 4.0 mm, preferably 2.0.
It is about 3.0 mm. This protrusion length is 1.5mm
If it is smaller than this, the abutment of the tab on the outer surface of the container is reduced, so that the bridge is hardly cut at the time of opening, and the protruding length is 4.0.
If it is larger than mm, molding becomes difficult and capping becomes difficult. The number of tabs 11 to be formed, the circumferential length of the tabs 11 and the interval between the tabs 11 are not particularly limited. For example, when 12 tabs are formed on the inner wall surface of the TE ring portion 9 having an inner diameter of about 29 mm. The circumferential length of the tab 11 is about 4 to 7 mm, and the gap between the tabs is 0.5 to 3.5.
mm. When the circumferential length of the tab 11 is smaller than 4 mm, the locking force of the tab 11 to the container opening is weakened, and there is a possibility that a bridge cutting failure may occur.
If it is larger than mm, the mechanical strength of the tab 11 increases and it becomes difficult to form. Further, the thickness of the tab 11 may be uniform, or the tip portion may be made thicker or thinner. Usually, the thickness of the tab 11 is 0.2 to 1.2 mm, preferably 0.6 to 1.0 mm.
mm. If the tab thickness is less than 0.2mm,
The tab is easily bent, so that the TE ring 9 cannot be guided downward at the time of opening, and there is a possibility that a disconnection failure of the bridge may occur. If the tab thickness is larger than 1.2 mm, molding is difficult. It is not preferable because the capping characteristics are also deteriorated. When the thickness of the distal end portion is larger than the proximal end portion of the tab 11 (the inner wall side of the TE ring 9), for example, the proximal end length is about 0.3 to 0.7 mm, and the distal end length is 1.
When the thickness is about 5 to 2.5 mm, the base thickness is 0.4 to
It is desirable that the thickness be 0.6 mm and the thickness of the tip be 0.5 to 1.0 mm. If the base end portion thickness and the tip end portion thickness of the tab are smaller than the above ranges, the strength (bending resistance) of the tab 11 is weak when the cap 1 is attached to the container mouth 21A and turned in the opening direction. In this case, the tab engaged with the pressing portion 24 is bent with its tip directed downward, so that the cap 1 may come off the container opening 21A without separating the TE ring portion 9 from the main portion 8, which is not preferable. When the thickness of the base end portion and the thickness of the distal end portion of the tab 11 are larger than the above ranges, the tab 1
1 (unbending strength) increases unnecessarily, and when the cap 1 is mounted on the container opening 21A, the resistance when the tab 11 passes through the pressing portion 24 increases, so that the cap 1 has a predetermined resistance. There is a possibility that inconvenience that the stopper cannot be sufficiently opened up to the screwing end angle may occur.

The number of the bridges 6 is particularly limited.
However, the sum of the cross-sectional areas of all the bridges 6 is 0.3 to
9.0mm^TwoOf the bridge 6 during tensioning
The total shear strength is about 10 to 18 kg. bridge
The sum of the cross-sectional areas of 6 is 9.0 mm ^TwoBigger, bridge
If the breaking strength (at the time of tension) is greater than 18 kg,
Caps come off without breaking the bridge, BBA is large
Tamper evidence characteristics (opening display characteristics)
It may be worse. The sum of the cross-sectional areas of the bridge 6 is
0.3mm^TwoSmaller, bridge breaking strength (tensile)
Is smaller than 10kg, the bridge will be
There is a risk of being cut off.

The resilient projection 12 is pushed radially outward by the container opening 21A via the seal projection 13 with the cap 1 attached to the container opening 21A. It is necessary to have strength to return to When this resilient projection has a length of about 1.5 mm, its thickness is about 0.5 to 1.0 mm. 0.5 thickness
mm, seal projection 1 when cap 1 is attached
There is a possibility that the pressing force of No. 3 is weakened and the sealing performance is deteriorated. On the other hand, if the thickness is larger than 1.0 mm, the mechanical strength becomes high, it becomes difficult to attach the cap, and there is a disadvantage that the closing torque and the opening torque are increased. When the cap 1 is attached to the container mouth 21A, the seal projection 13
It is necessary to have enough flexibility to be able to bend easily by contacting the mouth 21A. Preferably, the thickness of the tip portion in contact with the container mouth 21A and the resilient projection 12 is 0.5 to 1.0 m.
m.

The container 21 has a male screw 22 formed on the outer periphery of the upper end of the mouth thereof, an annular bulge 23 provided below the male screw 22, and a flange-like member provided below the annular bulge 23. Is formed. When the cap 1 attached to the container opening 21A is turned in the opening direction (counterclockwise), the annular bulging portion 23 engages with the tab 11 of the cap 1 and pushes the tab 11 down. Pressing part 24
And a horizontal extension step 25 which engages with the tab 11 pushed down by the pushing section 24 and prevents the tab 11 from moving upward.
Are provided in the circumferential direction. Note that the number of the bridge stretching means 26 is not limited to this embodiment, and may be one or more.

The pressing portion 24 has an inclined surface that gradually bulges downward in the cap opening direction when the cap 11 is opened. In addition, the extension step 25
A storage guide surface 27 is formed on the surface on the opposite side of the inclined surface to gradually reduce the protruding height in the cap opening direction. The inclination angle formed by the pressing portion 24 and the annular bulging portion is 5 to 5
It is set to 0 degrees. If this angle is larger than 50 degrees, when the cap 1 attached to the container opening 21A is turned in the opening direction, the resistance for pushing down the tab 11 becomes strong, and the tab may not be pushed down. On the other hand, if this angle is smaller than 5 degrees, BBA is undesirably increased.

The length from the annular bulge 23 to the extension step 25 is about 0.5 to 4.0 mm. If this length is smaller than 0.5 mm, the effect of pressing down the tab at the time of opening is not sufficiently exhibited, and BBA increases. If this length is larger than 4.0 mm, the excess portion Is disadvantageous in terms of cost. The length of the horizontal portion of the extension step 25 is 3 to 10 mm. If this length is smaller than 3 mm, BBA increases, and if it is larger than 10 mm, the excess portion becomes large, which is disadvantageous in cost.
The length of the pressing portion 24 (length of the inclined portion) is 1.5 to 8 mm.
It is said. If the length of this inclined portion is smaller than 1.5 mm,
When the cap is opened, the effect of pushing down the tab is not fully exhibited, and 8
If it is larger than mm, the excess portion becomes large, which is disadvantageous in cost. The inclination angle of the storage guide surface 27 is set to 15 to 60 degrees.

Next, the operation of the closing device according to the present embodiment will be described. After the container 21 is filled with the desired content liquid, the container 21 is conveyed to a cap mounting device (not shown), which supports the lower surface of the flange 29, and preferably covers the opening 21A with the cap 1 while conveying the container in a suspended state. , And are screwed and screwed clockwise. FIG. 2 shows an initial state of cap screwing. When the cap 1 is screwed into the container opening 21A, the upper end of the container opening 21A comes into contact with the lower surface of the seal projection 13. FIG. 3 shows a state in the middle stage of cap screwing. When the cap 1 is lowered in accordance with the screwing of the cap 1, the seal projection 13 is pushed up by the upper end of the mouth and comes into contact with the tip of the resilient projection 12. After that, the seal projection 13
It is bent along the upper end of the container opening 21A. FIG.
The state (mounting state) at the end of cap screwing is shown.
In this mounted state, the seal projection 13 is
It is sandwiched between the upper end of 1A and the resilient projection 12 and is pressed exactly against the outer surface of the upper end of the container opening 21A, so that the container opening 21A is completely sealed. The resilient projection 12 is pushed and bent radially outward via the seal projection 13, but biases the seal projection 13 in a direction to return to the original position, that is, radially inward. In the example of FIG. 4, the seal protrusion 13 is in contact with the outer surface of the upper end portion of the container mouth 21A at the time of mounting.
The seal projection 13 is further extended, so that the container
May be configured so as to reach the upper surface.

When the cap 1 is attached to the container opening 21A, the tabs 11 of the cap 1 pass through the annular bulging portion 23 with the tip folded upward, so that extra force is applied to the bridge 6. It does not work. Also, cap 1
In the final stage of mounting, the tab 11 that overlaps the four bridge extending means 26 in the mounted state passes through the annular bulging portion 23 so that the tip comes into contact with the outer peripheral surface of the container mouth below the annular bulging portion 23. In a state of being slightly opened inward in the radial direction, it comes into contact with the storage guide surface 27 of the bridge extending means 26. In this example,
When the tab 11 comes into contact with the tab storage guide surface 27 and moves in the closing direction by forming the storage guide surface 27 that gradually reduces the protruding height in the direction in which the cap is opened in the bridge extending means 26, this tab is used. 11 is folded with the tip thereof facing upward along the inclination of the tab storage guide surface 27, so that the bridge 6 is not cut.

In this way, the cap 1 is mounted on the container opening 21A by tightening the cap 1 with a predetermined closing torque value. In this cap mounted state, of the plurality of tabs of the cap 1, each of the tabs 11 excluding the tab that overlaps the bridge extending means 26 has its tip abutting on the outer peripheral surface of the container mouth below the annular bulging portion 23. Then, it is slightly opened radially inward. Further, the tab 11 overlapping the bridge extending means 26 is in a state where the tip is folded upward. As described above, the upper end of the container 21 is tightly sealed with the seal protrusion 13. In this mounting state, even if the upper end portion of the container mouth 21A falls inward and the bottle mouth falls, the resilient projection 12 moves inward in the radial direction in accordance with the fall, and falls down. Is maintained, the sealed state of the container opening 21A by the resilient projection 12 and the seal projection 13 is maintained.

The operation at the time of opening the closing device with the cap attached will be described. When the cap 1 is turned in the opening direction (counterclockwise), a slight rotational movement of the cap 1 causes
The tip of the tab 11 on the opening direction side is in contact with the pressing portion 24 of the bridge extending means 26 formed in the container opening 21A, and the tip of the tab 11 is gradually pushed down according to the inclination of the pressing portion 24. The tab 11 that has rotated the pressing portion 24 while being pressed down along the inclination of the pressing portion 24 smoothly transitions from the pressing portion 24 to the horizontal extension step 25. When the tab 11 reaches the extension step portion 25, the TE ring portion 9 is pushed down, while the main portion 8 rises along the male screw 22, so that the main portion immediately starts rotating in the opening direction. 8 and the TE ring portion 9 are separated from each other, and a plurality of thin bridges 6 connecting the main portion 8 and the TE ring portion 9 are stretched and cut or formed into a thin thread shape that is easily cut.

After the tab 11 moves from the pressing portion 24 to the extension step portion 25, the TE ring portion 9 is no longer depressed.
The main part 8 is still raised according to the external thread 22 so that the bridge 6 is further extended and the tab 11 is extended
5 is completely cut on the way. After that, the main part 8
Is further rotated in the opening direction to remove the main portion 8 from the container opening 21A.

The closing device according to the present embodiment includes a pressing portion 24 which engages with the tab 11 of the cap 1 and pushes down the cap 1 when the cap 1 attached to the mouth 21A is turned in the opening direction. The tab 1 pushed down by the pushing portion 24
Extension 25 that engages with the first and prevents upward movement
By providing at least one bridge extending means 26 having the following structure, the cap 1 attached to the container mouth 21A is provided.
Is turned in the opening direction, the pressing portion 2 of the bridge extending means 26 is
Since the tab 11 adjacent to the fourth side comes into contact with the pressing part 24 and is pressed down, and the TE ring part 9 is also pressed down, the main part 8 and the TE ring part 9 rising along the male screw 22 of the container 21 Are rapidly separated, and a plurality of narrow bridges 6 connecting the main part 8 and the TE ring part 9 are extended. Further, after the tab 11 shifts to the extension step portion 25, the TE ring portion 9 is prevented from rising, and the main portion 8 still rises along the male screw 22.
The bridge 6 is cut, and the TE ring portion 9 is separated from the main portion 8, which clearly indicates that the TE ring portion 9 has been opened. Therefore, according to this closing device, the cap 1 attached to the container opening 21A is rotated in the opening direction, and the bridge cutting angle (BBA) is the rotation angle up to the position where the bridge 6 is cut. Can be reduced to 90 degrees or less, preferably 45 degrees or less. Also, this cap 1
An annular resilient projection 12 extending downward from the periphery of the top plate 2 of the cap 1 to a boundary between the upper end of the cylindrical portion, and a tip extending toward the inner wall of the cylindrical portion 3 at least toward the inner wall. An annular sealing protrusion 13 having flexibility is provided integrally with the top plate portion 2. When the cap 1 is attached to the container opening 21A, the sealing protrusion 13 is bent by contacting the container opening 21A. Since the resilient projections 12 are configured to be pressed outward in the radial direction, a low-cost linerless cap can be obtained without applying another liner material to the cap body 4. When the cap 1 is attached to the container mouth 21A, the sealing projection 13 is pressed against the upper end of the container mouth 21A by the elastic force of the resilient projection 12 and is sealed.
It can be sealed securely. Further, the container mouth 21A
In the event of a bottle-mouth falling phenomenon in which the upper end of the bottle falls radially inward, the falling can be compensated for by the elastic projection 12 returning inward in the radial direction. Can maintain sex.

Note that the present invention is not limited to the above-described example, and various changes and modifications can be made. In the above embodiment, the container 21 is provided with the bridge extending means 26 having the pressing part 24 having the inclined surface and the horizontal extending step 25 from the annular bulging part 23. 26, for example, JP-A-62-251.
As described in JP-A-352-352 and JP-A-2-296666, a container having only an annular bulge may be used. When the bridge extending means 26 is provided, the extension step portion 25 may be omitted, and only the pressing portion 24 that can surely cut the bridge 6 when the plug is opened may be provided. Further, in the above embodiment, a plurality of tabs 11 are arranged in a row on the TE ring portion as the locking projections, but instead of the tabs 11, as described in JP-A-62-251352. It is good also as composition which arranged a suitable wing.

[0024]

EXAMPLE A closing device shown in FIG. 1 was manufactured and its sealing performance was confirmed. 33m outside diameter made of polypropylene
The cap 1 shown in FIG. 1 having a m, a height of 17 mm, a projection length of the resilient projection of 1.5 mm, a length of the seal projection of 4 mm, and a tip part thickness of 0.5 mm was produced. 0.3-
A prototype cap was changed to 1.5 mm, and a container (PET bottle) having a mouth structure shown in FIG. 1 was filled with hot water at 85 ° C., and immediately thereafter, the cap was attached using a capping machine manufactured by Alcoa and sealed. The sex was examined. (Sealing test) A cycle of 9 hours in a thermostat at 55 ° C. and 15 hours at room temperature was repeated twice for the sample after filling and cooling, and further, in a refrigerator at 5 ° C., checked whether there was any leakage after storage for 24 hours. To check. (Results)-Sample 1 with the thickness of the resilient projection being 0.3 mm was 50
Leaks occurred in 15 of the books. -Sample 2 having a thickness of the resilient projection of 0.5 mm is 50
No leakage occurred in the book. -Sample 3 having a thickness of the resilient projection of 1.0 mm is 50
No leakage occurred in the book.・ Sample 4 having a thickness of the resilient projection of 1.5 mm is 50
Leakage occurred in 20 of the books. As a result, when the protrusion length of the resilient projection is 1.5 mm, the thickness of the good resilient projection is 0.3 mm or more and 1.5 mm or more.
It was found to be less than about 0.5 mm, preferably about 0.5 to 1.3 mm, and more preferably about 0.5 to 1.0 mm. Note that the leak in the sample 1 occurs because the elastic projections have a low elasticity, and the pressure for pressing the seal projections against the container opening is weak. In the sample 4, the leaks have a high rigidity. , Due to incomplete mounting of the cap.

[0025]

As described above, the synthetic resin cap of the present invention and the closing device using the same are provided with the cap downward at any position from the periphery of the top plate of the synthetic resin cap to the upper end of the cylindrical portion. And an annular seal projection having a tip extending radially inward from the inner wall surface of the cylindrical portion below the elastic projection and having at least the tip end having flexibility. It is provided integrally with the plate part, and when the synthetic resin cap is attached to the container mouth, the seal projection comes into contact with the container mouth and bends, and the elastic projection is pressed radially outward. As a result, good sealing performance can be obtained in a linerless cap in which another liner material is not applied to the cap body, and a low-cost synthetic resin cap can be provided. In addition, when the synthetic resin cap is attached to the container mouth, the container mouth is sealed in a state where the sealing projection is pressed against the upper end of the container mouth by the elastic force of the resilient projection, so that the sealing is securely performed. be able to. Furthermore, when a bottle mouth falling phenomenon in which the upper end of the container mouth part falls inward in the radial direction occurs, the falling can be compensated for by the resilient projection returning radially inward, and the bottle mouth falling phenomenon occurs. Even in such a case, the hermeticity can be maintained, so that it is excellent in adaptability to a container.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view showing an example of a closing device of the present invention.

FIG. 2 is an essential part cross-sectional view showing the same closing device in an initial state of cap screwing.

FIG. 3 is a cross-sectional view of a main part showing a state in the middle of the cap screwing similarly.

FIG. 4 is a cross-sectional view of a main part showing a state where the cap screw connection is completed similarly.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... synthetic resin cap, 2 ... top plate part, 3 ... cylinder part, 4 ... cap body, 6 ... bridge, 7 ... horizontal score, 8 ... main part, 9 ... TE ring part Reference numeral 10: screw portion, 11: tab, 12: resilient projection, 13: seal projection, 21: container, 21A: container mouth portion, 22:
Male screw, 23 ... Annular bulge, 24 ... Pressing part, 25 ...
... extension step, 26 ... bridge extension means, 27 ... storage guide surface.

Claims (6)

[Claims] 1. A cap body comprising a top plate portion and a tubular portion hanging down from the periphery thereof, the tubular portion being formed by a weakening line with a main portion above the weakening line and a tamper evidence ring portion below the weakening line. In a synthetic resin cap that is partitioned and has a threaded portion formed on the inner wall surface of the main portion, and a plurality of undulating projections provided on the inner wall surface of the tamper evidence ring portion, An annular resilient projection extending downward to any position up to the upper end of the cylindrical portion, and a tip extending radially inward from the inner wall surface of the cylindrical portion below the resilient projection, at least the distal end portion A synthetic resin cap, wherein a flexible annular seal projection is provided integrally with the top plate portion. 2. A cap body comprising a top plate portion and a tubular portion hanging down from the periphery thereof, wherein the tubular portion is cut by a weakening line, and a main portion above the weakening line, and a lower tamper evidence ring. A synthetic resin cap defined by a threaded portion formed on an inner wall surface of the main portion, and provided with a plurality of undulating protrusions protruding from an inner wall surface of the tamper evidence ring portion; And a container having an annular bulge formed below the male screw on the outer periphery of the upper end of the top plate. An annular resilient projection extending downward to any position from the to the upper end of the cylindrical portion, and a tip extending radially inward from the inner wall surface of the cylindrical portion below the resilient projection, at least the distal end portion Is a flexible annular seal When the synthetic resin cap is attached to the container mouth, the seal projection comes into contact with the container mouth and bends, and the resilient projection is radially outward. A closing device characterized in that the closing device is pressed. 3. The synthetic resin cap is provided with a plate-shaped undulating tab as a locking projection, and the container is provided with the synthetic resin cap mounted on the bulging portion at the container opening. When turned in the opening direction, a pressing portion having an inclined surface that gradually bulges downward in the cap opening direction is formed, which is engaged with the tab of the cap to push down the tab. 3. The closing device according to claim 2, wherein 4. The closure according to claim 3, wherein the pressing portion is provided with an extended step portion that engages with the tab pressed down by the inclined surface and prevents the tab from moving upward. apparatus. 5. The closing device according to claim 3, wherein a side of the extension step portion opposite to the inclined surface is a storage guide surface that gradually reduces a protruding height in a cap opening direction. 6. A bridge cutting angle, which is a rotation angle up to a position at which a bridge is cut, by rotating a cap attached to a container mouth in an opening direction, and is 90 degrees or less. The closing device according to any one of claims 1 to 5.