JP2009161227A - Cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cap capable of securely preventing splash when opened. <P>SOLUTION: The cap has a vent slit 4 at the upper part of a skirt part 2, and a sealing liner 7 having a flat plate part 7a for covering the central part of the inner surface of a top plate part 1 and a sealing part located at the peripheral part of the top plate part 1 and sealing a curled part 8 at the inner surface side of the top plate part 1. The sealing part includes a flat part 7b which abuts on the top portion of the curled part 8 and an inner rib 7c which abuts on the inner circumferential surface of the curled part 8. When the curled part 8 is sealed by the sealing liner 7, the outer circumferential surface of the inner rib 7c of the sealing liner 7 is brought into close contact with the inner circumferential surface of the curled part 8 and the lower end of the inner rib 7c is located to coincide with a central part O in a longitudinal sectional shape of the curled part 8 or is located above the central part O. The thickness of the lower surface of the inner rib 7c in the radial direction of the cap is 0.4-1 mm, and a thick-walled part 7e is formed at a connection part between the inner rib 7c and the flat plate part 7a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cap having a sealing liner that prevents the contents from being blown out together with the gas when the gas inside the container escapes at the time of opening, in a container having a positive internal pressure.

  Conventionally, as a container filled with contents such as carbonated drinks and coffee, a resealable metal bottle-shaped can sealed by a sealing liner formed on the inner surface of the top plate portion of the metal cap has been used. Yes. As such a bottle-shaped can, Patent Document 1 discloses that the inner seal protrusion of the liner provided on the inner surface of the top plate portion of the cap is provided on the curl portion having a substantially circular longitudinal section which is the opening end portion of the container. There is described a cap that seals the container by bringing the outer seal projection of the liner into close contact with the outer peripheral surface of the open end while being in close contact with the inner peripheral surface of the end.

JP 2007-230640 A

  On the other hand, when the container pressure is positive, such as when the contents are carbonated beverages or when liquid nitrogen is sealed in the container, it is made of metal so that the pressure inside the container can be quickly released when the container is opened. A thing in which a vent slit formed by cutting a part of the skirt portion in the circumferential direction is formed above the skirt portion of the cap is used.

  However, when the outer peripheral surface of the inner seal protrusion of the liner is in close contact with the inner peripheral surface of the curl portion having a substantially circular longitudinal section as in the invention described in Patent Document 1, the lower half of the inner peripheral surface of the curl portion is the inner side. The upper part of the inner peripheral surface of the curl part and the upper part of the outer peripheral surface of the inner seal protrusion are in close contact with each other because it is curved away from the seal protrusion, but the lower part of the inner peripheral surface of the curl part and the outer peripheral surface of the inner seal protrusion A gap is formed without being in close contact with the lower part of the substrate. In such a cap, when the container is vibrated or laid down, the contents may enter and accumulate in the gap between the lower part of the inner peripheral surface of the curled part and the lower part of the outer peripheral surface of the inner seal protrusion, When the container is opened in this state, the contents accumulated in the gap between the lower part of the inner peripheral surface of the curled part and the lower part of the outer peripheral surface of the inner seal protrusion when the internal pressure of the container is released from the vent slit. There is a risk that it will blow out to the outside of the container together with other gases and adhere to consumers' hands and clothes.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a cap that can effectively prevent the content from being blown out (that is, splash) when the container is opened.

  In order to achieve the above object, the invention according to claim 1 is a cap for sealing a container having a curled portion having a substantially circular longitudinal section at the opening end of the mouth, the top plate portion and the ceiling. A skirt part hanging from the peripheral part of the plate part, and a vent slit formed by cutting a part of the skirt part is formed in the upper part of the skirt part, and on the inner surface side of the top plate part, A sealing liner provided with a flat plate portion covering a central portion of the inner surface of the top plate portion and a sealing portion located at a peripheral portion of the top plate portion and sealing the curled portion; The cap has a flat portion that contacts the top of the curled portion and an inner rib that contacts the inner peripheral surface of the curled portion at the peripheral edge of the sealing liner. When sealed, the sealing liner The outer peripheral surface of the inner rib is in intimate contact with the inner peripheral surface of the curled portion, and the lower end of the inner rib is positioned to coincide with the central portion in the longitudinal sectional shape of the curled portion or above the central portion. And the thickness of the lower surface of the inner rib in the radial direction of the cap is in the range of 0.4 to 1 mm, and a thick portion is formed at a connection portion between the inner peripheral surface of the inner rib and the outer surface of the flat plate portion. It is characteristic that it is formed.

  A second aspect of the present invention is the cap according to the first aspect of the present invention, wherein a cap axial direction distance between a lower end of the inner rib and a lower surface of the flat portion is 0.5 to 1 mm.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the thick portion is in a range from a lower end portion of the inner rib to a peripheral portion of the flat plate portion, and from the lower end portion of the inner rib to the flat plate portion. The cap is characterized in that it is formed so as to gradually increase its thickness toward the peripheral edge of the cap.

  According to the first aspect of the present invention, when the curled portion is sealed with the sealing liner, the outer peripheral surface of the inner rib of the sealing liner is in close contact with the inner peripheral surface of the curled portion, and the lower end of the inner rib is the curled portion. A lower portion of the inner peripheral surface of the curled portion that is curved in a direction away from the inner rib, and the inner rib. No gap is formed by the cap, and the thickness of the bottom surface of the inner rib in the radial direction of the cap is in the range of 0.4 to 1 mm. The lower end of the rib can be sufficiently in close contact with the curled portion, and a thick wall portion is formed at least at the connecting portion between the inner peripheral surface of the inner rib and the outer surface of the flat plate portion, so that a sealing liner is provided on the curled portion. When in close contact Ribs can be effectively prevented from falling down radially inward of the cap. As a result, it is possible to sufficiently suppress the occurrence of a gap between the inner rib and the curl portion, and to prevent the contents from blowing out together with the gas inside the container from the vent slit when the cap is opened (that is, splash). .

  According to the invention of claim 2, when the cap axial direction distance between the lower end of the inner rib and the lower surface of the flat portion is 0.5 to 1 mm, the top plate portion of the cap is pressed into the curled portion during capping. Even if the sealing liner is pressed, it is possible to reliably prevent the lower end of the inner rib from being positioned below the center in the longitudinal cross-sectional shape of the curled portion, and the shorter length makes the curled portion and the inner rib closer to each other. Sometimes, the inner rib can be prevented from falling inwardly in the cap radial direction.

  According to the invention of claim 3, the thick portion gradually increases in thickness from the lower end portion of the inner rib toward the peripheral portion of the flat plate portion in a range from the lower end portion of the inner rib to the peripheral portion of the flat plate portion. As a result, it is possible to sufficiently reinforce not only the connection part between the inner peripheral surface of the inner rib and the outer surface of the flat plate part, but also the vicinity of the lower end part of the inner rib, and therefore the adhesion between the inner rib and the curled part Can be ensured, and it is possible to more reliably suppress the occurrence of a gap between the lower end portion of the inner rib and the curled portion.

  The cap of the present invention comprises a cap shell made of a thin metal plate and a sealing liner made of a thermoplastic resin, and the cap is attached to the mouth portion of a metal bottle-shaped can having a screw portion at the mouth portion. After the crown is attached, the corners of the cap shell are drawn and roll-on so that the curl portion having a substantially circular longitudinal section located at the opening end of the mouth portion of the container and the sealing liner are in close contact with each other. The container is used to seal the container by threading so as to be screwed into the threaded portion of the mouth by the capper. The curl portion having a substantially circular longitudinal section is an arc shape in which at least a half or more of the longitudinal sectional shape of the curled portion (that is, the sectional shape appearing when cut along a plane along the central axis of the mouth) is continuous. It is a curled portion that is formed.

  As the material of the cap shell, conventionally known metal plates for caps such as aluminum alloy plates and surface-treated steel plates are used. In addition, at least the inner surface side of the cap shell is covered with a synthetic resin coating such as a synthetic resin coating or film, and in particular, a protective coating made of a polymer that is adhesive to the resin material of the sealing liner may be provided. It is desirable to eliminate the need for an adhesive. In addition, as a resin paint constituting the synthetic resin film, an epoxy resin or a polyester resin can be suitably used, and as a resin film, an olefin resin such as polyethylene or polypropylene, or a polyester resin such as polyethylene terephthalate, etc. Can be suitably used.

  As shown in FIG. 1, the cap or cap shell of the present invention is formed by drawing a metal plate as described above with a press or the like, thereby forming a disk-shaped top plate portion 1 and a cylindrical skirt portion 2. Are formed integrally in a cup shape, and after drawing, a knurl portion 3 is formed on the upper portion of the skirt portion 2 in which concave portions 3a and convex portions 3b are alternately repeated over the entire circumferential direction. A vent slit 4 extending in the circumferential direction is formed in the upper part of the recess 3a of the knurled portion 3 so as to quickly discharge the gas inside the container when the container is opened. A rupture line 5 is formed at the lower portion of the skirt portion 2 by a plurality of bridges 5 a and slits 5 b extending in the circumferential direction. The skirt portion 2 is formed by a main portion above the rupture line 5 and a rupture line 5. Is also divided into a lower pilfer proof band portion 6.

  Further, a sealing liner 7 made of synthetic resin is formed on the inner surface of the top plate portion 1 of the cap shell, and as the resin material of the sealing liner 7, an olefin resin, a polyester resin, a styrene resin, Conventionally known materials such as acrylic resins can be used. For example, a blend material of styrene elastomer and polypropylene resin, a blend material of low density polyethylene and styrene elastomer, a polyester elastomer, etc. can be suitably used. A pigment, a lubricant, a softener and the like can be appropriately added to these resins. In the present invention, the contact angle of water with the resin material of the liner 7 formed into a flat plate shape is used as the resin material of the sealing liner 7 so that the contents are less likely to adhere and remain on the surface of the sealing liner 7. It is preferable to use a material having a wetting angle of 70 degrees or more. For example, a blend material of a styrene elastomer and a polypropylene resin is preferably used.

  The sealing liner 7 is a state in which such a resin material is melted, supplied to the inner surface side of the top plate portion 1 of the cap shell, and the resin material is embossed into a predetermined shape by a mold. A flat plate portion 7a covering the central portion of the inner surface of the top plate portion 1; and a sealing portion located at the peripheral portion of the top plate portion 1 for sealing the open end of the mouth portion of the container. Are formed so as to protrude downward from the inner peripheral edge of the flat portion 7b, and to be in contact with the top of the curled portion 8 which is the opening end of the mouth portion of the container. The inner rib 7c is in close contact, and the outer rib 7d is formed so as to protrude downward from the outer peripheral edge of the flat portion 7b and is in close contact with the outer peripheral surface of the curled portion 8.

  In the present invention, the cap axis direction distance L1 between the lower surface of the flat portion 7b of the sealing liner 7 and the lower end of the inner rib 7c is set in the range of 0.5 to 1 mm as shown in FIG. The thickness T1 in the cap radial direction of the lower surface of 7c is set in the range of 0.4 to 1 mm, and the cap axial direction distance L2 between the lower surface of the flat portion 7b and the lower end of the outer rib 7d is 0.2 to 0. The thickness T2 in the cap radial direction on the lower surface of the outer rib 7d is set in the range of 0.5 to 1.5 mm, and sealing is performed from the inner surface of the top plate portion 1 of the cap shell. The cap axial direction distance L3 to the lower surface of the flat portion 7b of the liner 7 is set in the range of 0.5 to 1.5 mm. Further, the inner peripheral surface of the sealing portion gradually increases in thickness from the lower end of the inner rib 7c toward the peripheral portion of the flat plate portion 7a in a range from the lower end of the inner rib 7c to the peripheral portion of the flat plate portion 7a. A thick wall portion 7e having an arcuate vertical cross section is formed.

  The thick portion 7e may be formed at least at the connection portion between the inner peripheral surface of the inner rib 7c and the outer surface of the flat plate portion 7a in terms of preventing the inner rib 7c from falling down. In order to sufficiently reinforce the vicinity of the portion, the thickness is gradually increased from the lower end portion of the inner rib 7c toward the peripheral portion of the flat plate portion 7a in the range from the lower end portion of the inner rib 7c to the peripheral portion of the flat plate portion 7a. It is preferable to form as follows. Further, the inner peripheral surface shape of the thick portion 7e is not limited to the one having a circular section in the longitudinal section, but may be one in which the longitudinal section is formed in a straight line or a combination thereof.

  The cap of the present invention having such a sealing liner 7 is put on the mouth portion 9 of a metal bottle-shaped can having a substantially circular curled portion 8 having a longitudinal section and a radius of 1.2 mm at the opening end of the mouth portion. The top plate portion 1 of the cap is pressed downward in the can axis direction with a load of about 900 N, and the corner portion 10 between the top plate portion 1 and the skirt portion 2 is drawn as shown in FIG. When capping by pressing the skirt part 2 with a threading roll along the male thread part formed in the mouth part 9 of the bottle-shaped can with the plate part 1 being pressed, and forming the female thread part on the skirt part 2, The flat portion 7b of the liner 7 is in close contact with the top of the curled portion 8, the inner peripheral surface of the outer rib 7d is in close contact with the outer peripheral surface of the curled portion 8, and the outer peripheral surface of the inner rib 7c is the inner peripheral surface of the curled portion 8. The lower end of the inner rib 7c And thus it is disposed so as to be positioned above the position or said center portion O substantially coincides with the center O of the vertical section of the part 8.

  According to such a cap of the present invention, when the curled portion 8 is sealed by the sealing liner 7, the outer peripheral surface of the inner rib 7 c of the sealing liner 7 is in close contact with the inner peripheral surface of the curled portion 8, and the inner side The lower end of the rib 7c is positioned so as to coincide with the central portion O in the longitudinal sectional shape of the curled portion 8 or is positioned above the central portion O, so that the curled portion 8 curved in a direction away from the inner rib 7c. No gap is formed between the lower portion of the inner rib 7c and the inner rib 7c, and the thickness of the lower surface of the inner rib 7c in the cap radial direction is in the range of 0.4 to 1 mm. The strength of the lower end portion is sufficiently secured, the lower end portion of the inner rib 7c can be sufficiently intimately contacted with the curled portion 8, and the thick portion is at least connected to the inner peripheral surface of the inner rib 7c and the outer surface of the flat plate portion 7a. 7e is formed By are, when brought into close contact with the sealing liner 7 to the curl portion 8, can be effectively prevented that the inner ribs 7c from falling down radially inward of the cap. As a result, it is possible to prevent a gap from being formed between the inner rib 7c and the curled portion 8, and to sufficiently suppress the contents from being blown out together with the gas inside the container from the vent slit 4 when the cap is opened.

  That is, when the lower end of the inner rib 7c is positioned below the center portion O in the longitudinal sectional shape of the curled portion 8, the curled portion 8 having a substantially circular longitudinal section is curved in a direction away from the inner rib 7c. Since the inner rib 7c cannot be brought into close contact with the lower part of the inner peripheral surface of the curled portion 8, a gap is generated between the curled portion 8 and the lower end of the inner rib 7c. If the thickness of the lower surface of the inner rib 7c in the cap radial direction is less than 0.4 mm, the inner rib 7c cannot be sufficiently strong, and the inner rib 7c does not sufficiently adhere to the curled portion 8 and is sealed. If the thickness of the lower surface of the inner rib 7c in the cap radial direction is greater than 1 mm, the sealing liner 7 may be damaged. Therefore, a large amount of resin material is required, which may increase production cost and decrease production speed.

  Further, by setting the cap axial distance L1 between the lower end of the inner rib 7c and the lower surface of the flat portion 7b to be in the range of 0.5 to 1 mm, the top plate portion 1 of the cap is pressed when the container is sealed with the cap. Even if the sealing liner 7 is pressed against the curled portion 8, the lower end of the inner rib 7 c can be prevented from being positioned below the center portion O in the longitudinal sectional shape of the curled portion 8, and the curled portion is short because of its short length. When the 8 and the inner rib 7c are in close contact with each other, the inner rib 7c can be prevented from falling inward in the cap radial direction. That is, if the cap axis direction distance L1 between the lower end of the inner rib 7c and the lower surface of the flat portion 7b is shorter than 0.5 mm, there is a possibility that the sealability of the inner peripheral surface of the curled portion 8 by the inner rib 7c cannot be sufficiently secured. Further, if the cap axial distance L1 between the lower end of the inner rib 7c and the lower surface of the flat portion 7b is longer than 1 mm, the inner rib is pressed when the top plate portion 1 of the cap is pressed and the sealing liner 7 is pressed against the curled portion 8. There is a possibility that the lower end of 7c may be positioned below the center portion O in the longitudinal cross-sectional shape of the curled portion 8, and the inner rib 7c has a cap radius when the curled portion 8 and the inner rib 7c are in close contact with each other due to the longer length. There is a risk that a gap will be easily formed between the curled portion 8 and the inner rib 7c. Further, the thick portion 7e gradually increases in thickness from the lower end portion of the inner rib 7c toward the peripheral portion of the flat plate portion 7a in the range from the lower end portion of the inner rib 7c to the peripheral portion of the flat plate portion 7a. By being formed, not only the connection portion between the inner peripheral surface of the inner rib 7c and the outer surface of the flat plate portion 7a but also the vicinity of the lower end portion of the inner rib 7c can be sufficiently reinforced, so the inner rib 7c and the curled portion 8 Can be further ensured, and the occurrence of a gap between the lower end portion of the inner rib 7c and the curled portion 8 can be more reliably suppressed.

It is a half sectional view showing an example of a cap concerning the present invention. It is a fragmentary sectional view for demonstrating the dimension of each part of the liner for sealing. It is a fragmentary sectional view which shows the state which capped the cap which concerns on this invention to the container opening part by roll-on molding.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Top plate part, 2 ... Skirt part, 4 ... Vent slit, 7 ... Sealing liner, 8 ... Curl part, 9 ... Mouth part.

Claims (3)

A cap for sealing a container having a curled part having a substantially circular longitudinal section at an opening end of a mouth part, comprising a top plate part and a skirt part depending from a peripheral part of the top plate part, the skirt A vent slit in which a part of the skirt portion is cut is formed at the top of the portion, and on the inner surface side of the top plate portion, a flat plate portion covering a central portion of the inner surface of the top plate portion, A sealing liner is provided at a peripheral portion of the top plate portion and includes a sealing portion for sealing the curled portion, and the sealing portion is provided at a peripheral portion of the sealing liner at a top portion of the curling portion. In a cap having a flat part that comes into contact with the inner rib and an inner rib that comes into contact with the inner peripheral surface of the curled part,
When the curled portion is sealed by the sealing liner, the outer peripheral surface of the inner rib of the sealing liner is in close contact with the inner peripheral surface of the curled portion, and the lower end of the inner rib is a longitudinal section of the curled portion. The inner rib is located at or above the center of the surface shape, and has a thickness in the cap radial direction of the lower surface of the inner rib in the range of 0.4 to 1 mm. A cap having a thick portion formed at a connecting portion between the inner peripheral surface of the flat plate and the outer surface of the flat plate portion.   The cap according to claim 1, wherein a cap axial direction distance between a lower end of the inner rib and a lower surface of the flat portion is in a range of 0.5 to 1 mm.   The thick portion is formed so as to gradually increase in thickness from the lower end portion of the inner rib toward the peripheral portion of the flat plate portion in a range from the lower end portion of the inner rib to the peripheral portion of the flat plate portion. The cap according to claim 1, wherein the cap is provided.

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