JP4707172B2 - Can container with pilfer proof cap - Google Patents

Description

  The present invention relates to a can container in which a pill fur proof cap is attached so that it can be resealed (resealed) with respect to a metal can body, and in particular, in a can container with such a pill fur proof cap, The present invention relates to a can container sealing structure comprising an outer curl portion formed at an upper end of a body neck portion and a resin liner provided on a lower surface side of a top plate portion of a pilfer proof cap.

  In recent years, can containers for beverage cans, such as bottle-type cans, in which metal pill fur proof caps (tamper evidence caps) are mounted on the mouth and neck of metal can bodies by roll-on molding, are widely used. In such a can container, the upper end of the mouth and neck portion of the can body is formed in an outer curled portion, and a sealing resin is formed on the lower surface side of the top plate portion of the cap. A liner is provided, and the tightness of the can container is secured by the close contact between the curled portion and the liner.

  Regarding the sealing structure of the can container by the curl portion of the mouth and neck and the liner of the cap, conventionally, the curl portion has a shape of a longitudinal section (a section by a plane including the central axis of the can body). In this case, the curl width (curl diameter in the lateral direction) is relatively large, and the top of the curl and the liner are in contact with each other over a wide area. There is a tendency for the force to become weaker and the sealing performance to worsen. To prevent this, the stopper load (pressing load that presses the cap from above) when mounting the cap is increased, and the top of the curl portion and the liner If the adhesion force is increased, the curled portion itself may be deformed to deteriorate the sealing performance, or the can body may be bent under the curled portion.

  In addition, in the curled portion that is ring-shaped when viewed from above, the outer diameter of the curled portion (ring outer diameter) is predetermined in relation to the cap diameter so that the screw portion of the cap does not interfere with the curled portion. In this case, the slope formed between the upper end of the threaded portion and the curled portion has a larger inward slope of the inclined surface as the curl width is larger (horizontal direction). When the cap is mounted, when it receives a load in the vertical direction from the top, or when it receives an impact from the cap side due to dropping, etc., it will be cramped at the inclined portion. It is likely to occur.

  In order to solve such a problem, when a curled portion having a substantially circular longitudinal cross-sectional shape is formed, it is also conceivable to reduce the curl width by reducing the curl diameter of the substantially circular curled portion. However, at the tip portion of the mouth and neck where the curl portion is formed, the diameter reduction processing is performed before the curl processing, and the plate thickness is increased from the original plate thickness and the moldability is deteriorated. There is a limit to molding that makes the curl diameter small (curling with a small radius of curvature), and in practice, the curl width cannot be made smaller than a certain degree.

On the other hand, in the following Patent Document 1, a curl crushing process is performed on a curl portion having a substantially circular longitudinal cross-sectional shape, thereby forming a flat portion on the outer portion of the curl portion and the top of the curl portion. It is disclosed that by forming the protrusion on the cap, the protrusion is bitten into the packing (liner) of the cap, thereby improving the sealing performance at the opening of the can container. Further, in Patent Document 2 below, a multi-structured curled portion is formed so that the tip portion (cut end portion) is rolled into the curled portion and crushed in the width direction, and the vertical cross-sectional shape is substantially circular. It is disclosed that by making the curl width smaller than that of the curled portion, the top of the curled portion is bitten into the liner, and the sealing performance at the opening of the can container is improved.
JP 2001-213417 A JP 2004-26306 A

  By the way, in a can container such as a bottle-type can in which a metal pill fur proof cap is mounted on the mouth and neck of a metal can body by roll-on molding, the pill fur proof is detachable at a breakable bridge portion. The pilfer-proof cap with a ring (tamper-evidence band) that is integrally formed is mounted on the mouth and neck of the can body by roll-on molding. The threaded part of the mouth and neck and the threaded part of the cap are screwed together, and the lower end of the cap (pill) is aligned with the locking part formed below the threaded part of the mouth and neck. The lower end portion of the fur proof ring is deformed inward, and the lower end portion of the pill fur proof ring is locked to the locking portion of the mouth neck.

  When opening such a can container, the cap is rotated in the opening direction so that the cap moves upward while being guided by the screw portion. Since the upward movement is prevented by the stop portion, the bridge portion is broken and only the pilfer proof ring remains in the mouth neck portion, and the cap moves upward and is removed from the mouth neck portion. That is, if the cap is rotated from the unopened state and removed from the mouth and neck, the bridge part of the pilfer proof cap is broken, so if the can container is opened by mistake etc. Can check it easily.

  In such a can container with a pill fur proof cap, when it is desired to improve the sealing performance by the curl portion of the mouth and neck portion and the liner of the cap, the curl portion as disclosed in Patent Documents 1 and 2 above is used. It is conceivable to adopt a structure. However, in each of the curl parts disclosed in Patent Documents 1 and 2, the top part of the curl part bites into the liner of the cap in a state in which the cap is attached to the mouth and neck part. Is sufficiently secured, but if the cap is slightly rotated in the opening direction from that state, the pressure on the contact surface between the top of the curl and the liner (contact surface pressure) decreases and the contact state is released. Thus, the seal at this part is released.

  That is, when the cap is slightly rotated in the opening direction, the contact surface pressure between the top of the curl and the liner hardly decreases, and the top of the curl is strong against the liner to such an extent that the sealed state can be maintained. In the case where the cap is bitten, since the opening torque when the cap is rotated in the opening direction becomes very large, the opening performance is greatly deteriorated. Therefore, if the cap opening property is made favorable, the top of the curled portion cannot be so strongly bited into the liner.

  Further, in any of the curled portions disclosed in Patent Documents 1 and 2, the outer surface of the curled portion (the surface of the portion outside the top of the curled portion) is a flat surface (or a curved surface that is almost nearly flat). However, even if the liner is brought into close contact with the outer surface of such a curled portion as disclosed in Patent Document 1, sufficient sealing performance can be obtained only with the outer surface of the curled portion. I can't.

  On the other hand, in an unopened can container equipped with a pilfer proof cap, when opening the can container by rotating the cap in the opening direction, the cap begins to rotate, and at the same time, formed into a pilfer proof cap One of the plurality of bridge portions (hereinafter simply referred to as “bridge portion”) is not first broken, but when the cap is rotated by a certain angle, Breaking will begin. On the other hand, with respect to the sealing performance by the curled portion and the liner, the sealing of the top portion of the curled portion and the liner is released at the same time as the cap starts rotating as described above, and only the outer surface of the curled portion is However, it is not possible to obtain sufficient sealability with the liner.

  The rotation angle of the cap when the bridge portion first breaks (hereinafter referred to as “leak break angle”) than the rotation angle of the cap when the sealing at the top of the curl portion is released (hereinafter referred to as “leak break angle”). , Which is called “bridge break angle”), when turning the cap in the opening direction when opening, before turning the cap to the bridge break angle and breaking the bridge part first In addition, the rotation of the cap reaches the leak break angle, and the sealing between the curled portion and the liner is released, and there is a possibility that the beverage in the can leaks or the gas escapes. In such a can whose sealability has been lowered, there is a risk of causing a serious quality defect such as the contents of the microorganisms being spoiled by the microorganisms.

  Therefore, by adopting the structure of the curl portion disclosed in Patent Documents 1 and 2 above, even if the sealing performance of the can container is improved when the cap is attached, the unopened can container If the cap is slightly rotated to the extent that the bridge portion is not broken, there is a possibility of mischief such as leakage of the beverage or outgassing. In cans, since the internal pressure of the can is high, if the contact surface pressure between the curled part and the liner decreases even a little, the leakage of the beverage and the degassing are likely to occur. Since it cannot be confirmed from the state, the pilfer proof function cannot be performed sufficiently.

  Further, in the one disclosed in Patent Document 1, a curl crushing process is performed on a curl portion having a substantially circular longitudinal cross-sectional shape, thereby forming a flat portion on the outer surface of the curl portion and a radius of curvature at the top of the curl portion. Has formed a small protrusion, but when a protrusion having a small radius of curvature is formed in this way, a resin coating layer (on the surface of the metal plate by laminating a resin film or applying a paint ( In order to prevent cracks and peeling in the protective coating layer), corrosion of the can and deterioration of the quality of the contents may occur. Doing so increases the cost of canning.

  An object of the present invention is to solve the above-described problems. Specifically, for a can container with a pilfer-proof cap, sufficient sealing performance is ensured without deteriorating the opening performance. Further, it is an object of the present invention to make it possible to sufficiently perform the pilfer proof function.

In order to solve the above-described problems, the present invention, in order from the top, includes an outer curled portion, an inclined portion that is inclined upward and inward, a screw portion that is screwed with a screw portion of the cap, A pill fur proof cap provided with a sealing resin liner on the lower surface side of the top plate portion with respect to a metal can body having a mouth and neck portion each formed with a locking portion for locking the lower end. However, with the screw part of the cap screwed into the screw part of the mouth and neck part, the lower end of the pill fur proof ring of the cap is locked to the locking part of the mouth and neck part. In a can container with a pilfer proof cap attached to the part, the curled part of the outer winding curls upward and outward to rise from the upper end of the inclined part and reaches the top part of the curled part. To curl up to the maximum outer diameter of the curled part. It is formed so that the front end of the curled portion reaches the upper end of the inclined portion by curling inward and downward from the large outer diameter portion, and a curve indicating the surface of the curled portion when viewed in the longitudinal sectional shape of the curled portion, The curl width is made smaller than the curl height without being subjected to curl crushing processing, and is composed of a plurality of curves with different curvature radii. The resin liner of the cap is in close contact with the surface of the curl part to a position below the maximum outer diameter part of the curl part, and the thickness of the liner at the position below the maximum outer diameter part is the maximum outer diameter. It is characterized by being thicker than the thickness of the liner at the part.

  According to the can container with a pilfer-proof cap of the present invention as described above, the curl width (lateral curl diameter) is smaller than the curl height (vertical curl diameter) without performing crushing processing or the like. Since the curled portion is formed, the resin coating layer on the can surface is not damaged when the curled portion is molded. When the cap is attached to the mouth and neck by roll-on molding or the like, The top portion can be bitten into the resin liner of the cap, and the sealing performance can be improved.

  In addition, the outer surface of the curled portion is formed in a curved surface that protrudes outward, and a curved surface that curls inward below the maximum outer diameter portion, whereas the resin liner of the cap is The thickness of the liner at the position below the maximum outer diameter portion is in close contact with the surface of the curl portion from the top of the curl portion to a position below the maximum outer diameter portion. As the cap is rotated to open the can container, the top of the curl part moves away from the liner and seals at this part as the cap moves upward when the can container is opened. However, on the outer surface of the curl portion, the lower end portion of the liner moves upward from the lower position toward the maximum outer diameter portion until the lower end portion of the liner reaches the maximum outer diameter portion. Is due to the surface of the curled part gradually expanding in diameter. The liner is gradually compressed to increase the contact surface pressure, and even if the lower end of the liner gets over the maximum outer diameter, the compressed liner is restored and a certain section adheres to the curled surface. The maintained state will be maintained.

  Therefore, in general, the cap can be rotated to the bridge break angle at which the bridge portion breaks first, with the sealability between the curl portion and the liner sufficiently secured, and the bridge portion breaks. As a result, it is possible to reliably prevent mischief such as causing beverage leakage and gas spillage by slightly rotating the cap to such an extent that the bridge portion is not broken. Can be prevented, and the pill fur proof function can be sufficiently performed.

  In the present invention as described above, the lower end of the close contact portion between the liner and the curl portion positioned below the maximum outer diameter portion of the curl portion with the cap attached to the mouth and neck portion is set to the maximum of the curl portion. By positioning it in the range of 0.1 to 0.4mm in the horizontal direction inward from the surface of the outer diameter part, the lower end part of the liner comes into contact with the surface of the curl part as the cap rises, and the maximum outside When moving toward the diameter portion, without increasing the contact surface pressure between the curl portion and the liner on the outer surface of the curl portion more than necessary, the state in which the openability is maintained better, and A sufficient sealing property can be secured. Further, by setting the vertical distance between the maximum outer diameter portion of the curl portion and the lower end of the liner to be 0.4 mm or more (preferably 0.7 mm or more), the leak break angle is made sufficiently larger than the bridge break angle. And the pilfer proof function can be further ensured.

The purpose of the can container with a pilfer proof cap is to ensure sufficient sealing performance without deteriorating the openability, and to sufficiently fulfill the pilfer proof function. As specifically shown in the following embodiment as the best mode, in order from the top, the curl portion of the outer winding, the inclined portion inclined upward and inward, the screw portion screwed with the screw portion of the cap, A pilfer provided with a resin liner for sealing on the lower surface side of the top plate portion against a metal can body having a mouth and neck portion each formed with a locking portion for locking the lower end of the cap With the proof cap screwed into the screw portion of the mouth and neck, the lower end of the pill fur proof ring of the cap is locked to the lock portion of the mouth and neck portion. Pilfer proof on the mouth and neck In the can container to which the cap is attached, the curled portion of the outer winding is curled upward and outward so as to rise from the upper end of the inclined portion to reach the top of the curled portion, and curled downward and outward from this top portion. The maximum outer diameter portion of the curled portion is formed, curled inward and downward from the maximum outer diameter portion, and the leading end of the curled portion reaches the vicinity of the upper end of the inclined portion. The curl portion surface is formed by a series of a plurality of curves having different curvature radii so that the curl width is smaller than the curl height without performing curl crushing processing. The thickness of the liner at a position below the maximum outer diameter portion is such that the resin liner of the cap is in close contact with the surface of the curl portion to a position below the maximum outer diameter portion of the curl portion at the outer surface portion of The maximum outer diameter It was achieved by the fact that thicker than the thickness of the liner.

  This embodiment is a bottle-type can in which a metal cap is mounted on the mouth and neck of a metal can body by roll-on molding, and is a metal composed of the mouth and neck, a shoulder, a trunk, and a bottom. A sealing resin liner is integrally attached to the cap mounted on the mouth and neck of the can body on the lower surface side of the top plate portion of the metal cap shell. In addition, as for the can body and cap shell of the bottle type can, for example, a metal plate such as an aluminum alloy plate or a surface-treated steel plate, or a resin coating in which a resin layer is previously coated on the metal surface of such a metal plate It is manufactured from a conventionally used metal plate for can manufacturing, such as a metal plate. The sealing resin liner is manufactured from a conventionally used resin material for a liner such as a polyethylene resin or a polypropylene resin, and the resin used has a D hardness ( ASTM D2240) is preferably from 10 to 50. With resins whose D hardness is softer than 10, the liner is too soft and the opening torque increases, resulting in inferior opening performance. On the other hand, with resins whose D hardness is higher than 50, the liner is too hard and curls. It will be inferior to sealing performance because the bite into the worse.

  As for the can of the bottle type can, a type in which a separate bottom lid is wound and fixed to a seamless can body in which the mouth and neck, shoulder and trunk are integrally formed, or a bottomed cylinder The shape of the cylindrical body of the cylindrical seamless can body is reduced to the upper part of the cylindrical body, and the neck and shoulder are formed on the shoulder and mouth neck. There are various types, such as a type in which a separate top lid and a separate bottom lid that are integrally molded are wound and fixed, but a pill fur proof cap is attached to the mouth and neck. As long as it is, any type may be used.

  As shown in FIG. 2, the bottle neck of the bottle body can have an outer curl portion 21 and an upwardly inwardly inclined portion (increasing in diameter toward the upper side) as shown in FIG. A portion 22, a screw portion 23 that is screwed with a screw portion of the cap, and a locking portion 24 that locks the lower end of the cap are formed. A cap that has not yet been threaded with respect to such a neck and neck is subjected to a capping load from above, and roll-on molding is performed to match the threaded portion of the mouth and neck. A threaded part is formed on the peripheral wall, and the lower end part of the cap (the lower end part of the pill fur proof ring) is deformed inward according to the locking part of the mouth and neck part, so that it is attached to the mouth and neck part. .

  The cap that is attached to the mouth and neck of the can body is a cap with a function to prevent mischief called pill fur proof (or tamper evidence), and is attached to the mouth and neck of the can body by roll-on molding. As shown in FIGS. 1 and 2, the screw portion 12 is formed on the peripheral wall of the cap 1 so that the screw portion 23 of the mouth-and-neck portion 2 is screwed, and a bridge portion is formed below the screw portion 12. The pilfer proof ring 14 that is integrally connected via 13 is deformed inward so that the lower end thereof is locked to the locking portion 24 of the mouth-neck portion 2. The pilfer-proof cap 1 is integrally provided with a sealing resin liner 15 on the lower surface side of the top plate portion 11 of the metal shell.

  By the way, in the bottle type can of the present embodiment in which the pill fur proof cap is attached to the mouth and neck portion of the can body as described above, the outer curled portion formed at the upper end of the mouth and neck portion of the can body is , Rising from the upper end of the inclined part of the mouth and neck, curling upward and leading to the top of the curled part, curling downward from this top to reach the maximum outer diameter part of the curled part, this maximum outer diameter part The curled portion is curled inward and downward so that the tip of the curled portion reaches the vicinity of the upper end of the inclined portion. That is, the outer surface of the curl portion (the surface of the outer portion from the top portion) is formed as a curved surface that protrudes outward, and a curved surface that curls inwardly below its maximum outer diameter portion.

  In the shape of the longitudinal section of such a curled portion (cross section with a plane including the central axis of the can body), the curve indicating the surface of the curled portion has a curvature radius (R1, R2, R3, R4) as shown in FIG. , R5) are constituted by a series of different curves. Further, the curl width W (lateral curl diameter) of the curled part 21 is smaller than the curl height H (vertical curl diameter), and the longitudinal sectional shape of the curled part 21 is a vertically long oval. Yes. In the present embodiment, specifically, the outer diameter of the screw portion of the mouth and neck portion is about 28 mm and the ring outer diameter of the curled portion is about 25 mm, whereas the curled width W of the curled portion is 1.4 mm, The curl height H is 1.7 mm.

  The curl width W of the curled portion is preferably about 1.1 mm to 1.7 mm. If the curled width W is too small, the resin coating layer that covers the surface of the metal plate when the curled portion is formed. On the other hand, if the curl width W is too large, the amount of biting of the curled part against the cap liner cannot be secured, and sufficient sealing performance is secured. Can not do it.

  The curl height H of the curled portion is preferably about 1.3 mm to 2.1 mm. When the curl height H is excessively small, the curl width W is small enough to secure the amount of biting into the liner. Attempting to form the curled portion makes it difficult to cause cracking or peeling in the resin coating layer covering the surface of the metal plate or forming the curled portion due to an increase in forming force. On the other hand, if the curl height H is excessively increased, the frictional force between the curl portion and the liner becomes excessively large, and the plug opening torque is increased, so that the plug opening performance is deteriorated. If the curl height H is excessively increased, the horizontal distance from the surface of the maximum outer diameter portion of the curl portion to the lower end of the close contact portion between the liner and the curl portion, and the maximum outer diameter portion of the curl portion and the liner This is not preferable because the vertical distance from the lower end may not be sufficiently secured, and the function for preventing mischief of the pilfer-proof cap may not be sufficiently exhibited.

  By reducing the curl width W of the curled portion as described above, as shown in FIG. 3, the angle θ with respect to the horizontal direction of the inclined portion 22 below the curled portion 21 is increased (the inclined surface 22 is increased inwardly). It is possible not to incline). For example, when the outer diameter of the screw portion of the mouth and neck is about 28 mm and the outer diameter of the ring of the curl portion is about 25 mm, the angle θ of the inclined surface with respect to the horizontal direction is the angle θ of the conventional circular curled portion. In contrast to the angle of approximately 45 to 50 °, the angle θ of the inclined surface with respect to the horizontal direction can be set to 50 to 70 ° in the curled portion having a vertically long cross-sectional shape in the present embodiment. In the present embodiment, the inclined surface following the curled portion is inclined so that the angle θ with the horizontal direction is in the range of 50 to 70 ° (specifically, about 60 °).

  In this way, the inclined surface below the curled portion is inclined so that the angle θ with the horizontal direction is in the range of 50 to 70 °, and the inward inclination of the inclined surface is reduced (the inclination of the inclined surface is reduced). It is possible to increase the strength of the inclined part against the load in the vertical direction as much as possible in the vertical direction). Even if it is received, the can body can be prevented from being deformed so as to bend at the inclined surface portion.

  Specifically, in this embodiment, the curve indicating the surface of the curled portion in the longitudinal cross-sectional shape of the curled portion is a portion extending from the upper end of the curled portion inner surface rising from the upper end of the inclined portion of the mouth and neck portion to the top of the curled portion. The radius of curvature R1 is about 0.9 mm, the radius of curvature R2 at the top of the curled portion is about 0.5 mm, and the portion curled outward from the top of the curled portion to reach the maximum outer diameter portion of the curled portion. The radius of curvature R3 is about 0.9 mm, and the radius of curvature R4 at the maximum outer diameter portion of the curled portion is about 0.5 mm. The curled portion curls downward and inward from the maximum outer diameter portion of the curled portion to the tip of the curled portion. The radius of curvature R5 at all the parts is about 0.9 mm.

  That is, in this embodiment, the radius of curvature R2 of the top of the curled portion is the smallest, and the radius of curvature R4 of the largest outer diameter portion of the curled portion is the radius of curvature R3 of the other portion on the outer surface of the curled portion. , R5 is smaller. The maximum outer diameter portion refers to a range of a curve having a certain curvature including a point (P2 shown in FIG. 4) where the ring outer diameter of the curl portion is maximum, and the top portion is the apex of the curl portion (see FIG. A range of a curve having a certain curvature including P1) shown in FIG. Each point of P1, P2, and P3 shown in FIG. 4 is a point in the longitudinal section, but is actually a circular line.

  The radius of curvature R2 at the top of the curl and the radius of curvature R4 at the maximum outer diameter of the curl are both suitably in the range of 0.2 mm to 1.0 mm (preferably 0.3 mm to 0.7 mm). However, if it is smaller than 0.2 mm, the resin coating layer (protective coating layer made of a film or a coating film) covering the surface of the metal plate may be cracked or peeled when the curled portion is formed, If it is larger than 1.0 mm, the amount of biting of the curled portion with respect to the liner of the cap cannot be sufficiently secured, and the sealing performance cannot be sufficiently improved. Further, during retort processing, the internal pressure of the can rises due to heating, and the top plate portion of the cap bulges upward, so that the peripheral portion of the top plate portion of the cap is deformed radially inward and downward in the can axis direction. However, if the radius of curvature is smaller than 0.2 mm, the curl part bites into the liner too much due to the deformation of the cap during such retort processing, and the openability is deteriorated. The part may penetrate the liner and the sealing performance may decrease.

  A sealing resin liner 15 attached to the lower surface side of the top plate portion of the cap is provided on the mouth and neck portion of the can body with respect to the curled portion of the mouth and neck portion of the can body configured as described above. With the cap attached, as shown in FIG. 4, the curled portion 21 is in close contact with the surface of the curled portion 21 from the inner surface to the apex (P1), and on the outer surface of the curled portion 21, the apex ( P1) is in close contact with the surface of the curled portion 21 from the maximum outer diameter portion to a position (P3) below the maximum outer diameter portion, and in the range from the surface (P2) of the maximum outer diameter portion to the lower end of the liner (P4), The thickness (horizontal width) is such that the thickness of the liner 15 at a position below the maximum outer diameter portion (P4) is larger than the thickness t of the liner 15 at the maximum outer diameter portion (P4). Yes.

  In the present embodiment, the lower end of the close contact portion between the liner 15 and the curled portion 21 (that is, the position of P3) is the maximum outside of the curled portion 21 in a state where the cap is attached to the mouth and neck portion of the can body. It is located in the range of 0.1 to 0.4 mm at a distance L1 in the horizontal direction inward from the surface (P2) of the diameter portion, and the maximum outer diameter portion (P2) of the curled portion 15 and the lower end ( The distance L2 in the vertical direction with respect to P4) is 0.4 mm or more (preferably 0.7 mm or more).

  According to the bottle-type can with a pill fur proof cap of the present embodiment configured as described above, the curl portion is formed so that the curl width W is smaller than the curl height H without performing curl crushing processing or the like. Because it is formed in a vertically long oval shape, it does not damage the resin coating layer on the surface of the can during molding of the curled part, and when the cap is attached to the mouth and neck by roll-on molding etc., the curled part The top part (the part with the smallest radius of curvature R2) can be cut into the resin liner of the cap, the contact surface pressure between the top part of the curl part and the liner can be increased, and the adhesiveness can be kept good, sealing. Can be improved.

  In the present embodiment, the curvature radius R4 of the maximum outer diameter portion is made smaller than the curvature radii R3, R5 of the other portions on the outer surface of the curled portion, so that the maximum outer diameter of this small curvature radius R4 is obtained. The amount of biting into the liner can be ensured by the portion, and the sealing performance on the outer surface of the curled portion can also be improved.

  Also, the outer surface of the curled part is formed in a curved surface that protrudes outward, with the curved part curling inward below the maximum outer diameter part, whereas the liner of the cap is curled. The thickness of the liner 15 at the position below the maximum outer diameter portion (P2) is close to the surface of the curl portion to the lower position (P3) than the maximum outer diameter portion (P2). Since it is thicker than the thickness t of the liner 15 in (P2), when the cap is rotated to open the can container, as the cap moves upward, the top of the curl portion ( P1) moves away from the liner, and the seal at this part is released. However, on the outer surface of the curl part, the lower end part (P4) of the liner moves upward toward the maximum outer diameter part (P2). At the same time, the lower end (P4) of the liner is the maximum outer diameter (P2). Until it reaches, the liner is gradually compressed by the surface of the curled portion to increase the adhesion, and even if the lower end portion (P4) of the liner gets over the maximum outer diameter portion (P2), it is compressed. While the liner is restored, a certain section is kept in close contact with the surface of the curled portion.

  For this reason, the cap can be rotated until the bridge portion is first broken while the curl portion and the liner are sufficiently sealed. As a result, it is possible to reliably prevent mischief such as leakage of beverages and outgassing by slightly turning the cap to such an extent that the bridge portion is not broken without causing leakage or outgassing. And the pill fur proof function can be sufficiently achieved.

  In this embodiment, the lower end (P3) of the close contact portion between the liner and the curl portion located below the maximum outer diameter portion of the curl portion is attached to the maximum outer portion of the curl portion with the cap attached to the mouth and neck portion. By being positioned in the range of 0.1 to 0.4 mm at a distance L1 in the horizontal direction inward from the surface (P2) of the diameter portion, the close contact lower end portion (P3) of the liner is raised as the cap rises. When moving toward the maximum outer diameter part (P2) while being in contact with the surface of the curled part, the opening performance is improved without unnecessarily increasing the contact surface pressure between the curled part and the liner on the outer surface of the curled part. Can be sufficiently secured and the sealing performance can be sufficiently secured.

  That is, when the horizontal distance L1 between the surface (P2) of the maximum outer diameter portion of the curled portion and the close contact lower end portion (P3) of the liner is less than 0.1 mm, when the cap is raised, the curled portion The contact surface pressure between the curled portion and the liner on the outer surface of the liner cannot be increased so much that the sealing performance cannot be secured sufficiently. On the other hand, if the distance L1 exceeds 0.4 mm, When it is raised, the contact surface pressure between the curl portion and the liner on the outer surface of the curl portion becomes too large, and the opening torque at the time of opening is increased and the opening performance is deteriorated. Further, when a cap that has been opened once is re-plugged, the re-plugging torque increases and the re-plugging property deteriorates.

  In this embodiment, the vertical distance L2 from the maximum outer diameter portion (P2) of the curl portion to the lower end portion (P4) of the liner is 0.4 mm or more (with a cap attached to the mouth and neck portion). (Preferably 0.7 mm or more), when the can container is opened by rotating the cap in the opening direction, the leak break angle can be made sufficiently larger than the bridge break angle, and the pilfer The proof function can be further ensured.

  That is, with respect to the vertical distance L2 from the maximum outer diameter portion (P2) of the curled portion to the lower end portion (P4) of the liner, when the cap is rotated to the bridge breaking angle at which the bridge portion of the cap is first broken. For example, when the outer diameter of the screw portion of the mouth and neck is about 28 mm, the bridge break angle of the cap is about 45 to 85 °, In terms of the amount of increase, the distance is about 0.4 to 0.7 mm. Therefore, in order to ensure the pilfer proof function, the distance L2 is preferably longer than that.

  About the bottle type can of the present Example which has the above effects, the effect was confirmed with the sample of an Example, and the sample of a comparative example.

  As a sample of the example, a bottle-shaped can having an outer diameter of the body portion of about 45 mm, an outer diameter of the screw portion of about 28 mm, and an outer diameter of the curl portion of about 25 mm, and the curl width W is 1 4 mm, the curl height H is 1.7 mm, and the curvature radius of each part of the surface of the curl portion shown in FIG. 3 is R1 = 0.9 mm, R2 = 0.5 mm, R3 = 0.9 mm, R4 = It formed so that it might be set to 0.5 mm and R5 = 0.9 mm, and the inclination part below the curl part was formed so that angle (theta) with a horizontal direction might be 60 degrees. Then, after filling the bottle-shaped can with carbonated water as a content, a pill fur proof cap was attached to the mouth and neck of the bottle-shaped can by roll-on molding, and the can was sealed. The height from P2 to P3 shown in FIG. 4 is 0.75 mm at the close contact portion between the resin liner of the pilfer proof cap and the outer surface of the curl portion.

As a test of the pilfer proof function, each of the ten samples of the above-described examples was performed by rotating the cap in the opening direction by a human hand.
As an evaluation, rotate the cap slowly until the bridge part is cut first, judge that the carbon dioxide gas has not escaped until then, and judge that the carbon dioxide gas escaped before the bridge part broke. did.
As a result, good evaluations could be obtained for all 10 samples, and it was confirmed that the bottle-shaped can of this example had a good pill fur proof function.

In addition, as a drop sealing test, a sample placed on a horizontal floor using a weight having a weight of 500 g, a top surface that is a horizontal plane, and a bottom surface that is inclined by 10 ° with respect to a horizontal plane. From 30 cm directly above, the weight was dropped vertically with the top surface horizontal, and the bottom surface was collided with the sample cap, and it was confirmed whether leakage occurred in the sample.
In this test, in addition to the sample of the above example, as a sample of a comparative example, the curled portion has a substantially circular longitudinal cross-sectional shape, the curled portion has a curl width W of 2.6 mm, and the inclined portion has an angle θ of 50 °. Except for the above, using the same sample as the sample of the above example, it was confirmed whether or not leakage occurred in the sample by the above method for each 10 cans of the sample of the example and the comparative example.
To confirm the occurrence of leakage, measure the internal pressure before colliding the weight with a tactile pressure tester in advance, store the sample with the weight collided for 24 hours at room temperature, and then use the same tactile pressure tester. The internal pressure was measured, and a sample in which the internal pressure after the collision was lower than the internal pressure before the collision was judged as having leaked.
As a result, in the sample of the example, no leakage occurred in all 10 cans, whereas in the sample of the comparative example, leakage occurred in 4 out of 10 cans. It was confirmed that the mold can has improved drop sealing performance.

  As mentioned above, although the Example of the can container with a pilfer proof cap of this invention was described, this invention is not limited only to said Example, For example, as a can container, it shows in said Example. It may be a can container such as a wide-mouthed reseal can with almost no shoulder, and the pill fur proof cap mounted on the mouth and neck of the can container As shown in Fig. 2, it is common to use a cap having a metal shell for a metal can container. However, in some cases, a cap having a resin shell or a shell made of metal and resin is used. Needless to say, the design can be appropriately changed, such as a cap made of a composite material.

The side view which shows the state by which the pilfer proof cap is mounted | worn with the mouth neck part of the can container. The longitudinal cross-sectional view which shows the state by which the pilfer proof cap is mounted | worn with the mouth neck part of the can container about one Example of this invention. The longitudinal cross-sectional view which expands and shows the part of the curl part of the mouth neck part of the can container shown in FIG. FIG. 4 is a longitudinal cross-sectional explanatory view showing a state in which the resin liner is in close contact with the curl portion shown in FIG. 3.

Explanation of symbols

1 Cap (pill fur proof cap)
2 (can body) mouth and neck part 11 (cap) top plate part 12 (cap) screw part 13 (cap) bridge part
14 (cap) pilfer proof ring 15 (cap) liner 21 curl part (mouth neck) 22 slant part (mouth neck) 23 screw part (mouth neck) screw part 24 (mouth neck part) Stop

Claims (2)

In order from the top, an outer curled part, an inclined part inclined upward and inward, a screw part screwed into the screw part of the cap, and a locking part for locking the lower end of the cap are formed. A pilfer proof cap with a sealing resin liner on the bottom side of the top plate is screwed into the screw can of the mouth and neck against a metal can with a mouth and neck. In the can container in which the pill fur proof cap is attached to the mouth and neck of the can body so that the lower end of the pill fur proof ring of the cap is locked to the locking portion of the mouth and neck, The curled part of the outer winding curls upward and outward so as to rise from the upper end of the inclined part and reaches the top of the curled part, and curls downward and outward from this top part to reach the maximum outer diameter part of the curled part. Curl downward and inward from the maximum outer diameter End is formed so as to reach the vicinity of the upper end of the inclined portion, and, viewed in longitudinal section of the curled portion, the curve showing the surface of the curl portion, and the radius of curvature is constituted by a succession of different curved lines, Carl The curl width is smaller than the curl height without being crushed , and the cap's resin liner is located on the outer surface of the curl. It is in close contact with the surface of the curl part to a lower position, and the thickness of the liner at the position below the maximum outer diameter part is thicker than the thickness of the liner at the maximum outer diameter part. Can container with pilfer proof cap.   In a state where the cap is attached to the mouth and neck, the lower end of the close contact portion between the liner and the curl portion is in a range of 0.1 to 0.4 mm in a horizontal distance inward from the surface of the maximum outer diameter portion of the curl portion. The can container with a pilfer proof cap according to claim 1, wherein a vertical distance between the maximum outer diameter portion of the curled portion and the lower end of the liner is 0.4 mm or more. .

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