Abstract:
A holographic sealing member for a container comprises a heat actuated sealant or adhesive layer that secures the sealing member to a container, a metal foil sealing layer over and covering and adhesively bonded to the heat actuated sealant or adhesive layer, a holographic layer over and covering and adhesively bonding to the metal foil layer having an upper plastic layer and a lower embossed image layer, and a tab over and covering and adhesively bonded to the upper plastic layer that may be pulled to remove the tab and the plastic layer from a container, thereby exposing the lower embossed image layer which must then be perforated to gain access to the contents of the container.

Description:
CROSS-REFERENCE To RELATED APPLICATIONS 
     This application is a continuation of prior application Ser. No. 12/026,723, filed Feb. 6, 2008, which claims priority pursuant to 35 U.S.C. §119(e) to U.S. Provisional Application No. 60/896,816, filed on Mar. 23, 2007, which are both incorporated herein by reference in their entirety. This application also claims benefit of U.S. Provisional Application No. 61/936,218, filed Feb. 5, 2014, which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The invention relates generally to a laminated sealing member for closing the mouth of a container, the sealing member having a graspable tab on its upper surface to expedite its removal from the container, and the sealing member also having a holographic security seal layer. 
     DESCRIPTION OF THE RELATED ART 
     In the figures, the first digit of the reference numbers correspond to the figure number. The remaining two digits of the reference numbers for elements within the various figures that correspond to each other always match. Hence, the bottom hot melt adhesive layer, which is essentially same in all of the figures, is assigned the reference number  122  in  FIG. 1, 222  in  FIG. 2, 322  in  FIGS. 3, and 422  in  FIG. 4 . 
     It is often desirable to seal a bottle, jar, or other container having a screw-on cap by providing a sealing member that attaches across the mouth of the container before the cap is screwed down onto the container for the first time. When the cap is later removed after purchase, the purchaser must penetrate, break, or otherwise remove the sealing member before the contents of the container may be accessed. The cap may then be screwed back into place to keep the contents fresh and to keep the contents from spilling out. If the sealing member is not present when the container is first opened, or if it is damaged, then the purchaser knows that the contents of the container may have been tampered with. And as an anti-counterfeiting measure, such a sealing member may include a hologram visible to the purchaser after the cap is removed, the pattern of the hologram being a unique identifier of a particular manufacturer. 
     Many sealing members are known which have tabs attached to their upper surface to facilitate their removal. One simply grasps the tab and pulls it to one side, and the entire sealing member is removed from the container in a single motion. 
     U.S. Pat. No. 5,514,442, which issued to Michael P. Gaida, et al. on May 7, 1996 discloses the sealing member  100  shown, in a side cross-sectional view, in  FIG. 1  (which is derived from  FIG. 4  of the &#39;442 patent). (For clarity, the cross sectioning lines have been omitted from the layers  102 ,  104 , and  110  in  FIG. 1  and are shown in the urethane adhesive layers  114  and  116  and hot melt bonding material or adhesive layer  122 .) The sealing member  100  is a laminated structure the lower half of which is formed from an aluminum foil layer  110  the underside of which is bonded to a hot melt bonding material or adhesive layer  122 . The upper half of the sealing member  100  is formed from a sheet of bleached craft paper  102  the lower half of which is glued to a polyester layer  104  (most likely a sheet or film of PET, or Polyethylene Terephthalate). As shown, the upper and lower halves of the sealing member  100  are joined by means of an adhesive layer  116  which extends only halfway (left-to-center) and which joins the aluminum foil layer  110  to the polyester layer  104 , leaving a gap  124  to the right. The sealing member  100  is circular and is die-cut from a much larger sheet of laminated materials, the cutting being positioned to cause the gap  124  to be present in each sealing member  100 , thereby forming a removal tab that comprises the craft paper  102  and the polyester  104  layer above the gap  124  to the right in  FIG. 1 . The &#39;442 patent teaches that this circular sealing member  100  is inserted deep into a screw-on cap (not shown) which is then screwed onto a container (not shown). Induction heating applied to the neck of the container then heats up the aluminum foil layer  110 , causing the hot melt bonding material or adhesive layer  122  to melt and thereby seal the sealing member  100  to the top of the container. After the container is purchased, the purchaser removes the cap and then grasps and pulls on the removal tab and thereby removes the sealing member  100  from the container. 
     U.S. Pat. No. 6,866,926, which issued to Joe Smelko et al on Mar. 15, 2005, teaches the design of an improved sealing member  200  which is shown, in a side cross-sectional view, in  FIG. 2  ((which corresponds to FIG. 3 of the &#39;926 patent). (For clarity, the cross-sectional lines have been omitted from the layers  202 ,  204 ,  206 ,  208 ,  210 , and  212  in  FIG. 2  and are shown in the urethane adhesive layers  218  and  220  and hot melt bonding material or adhesive layer  222 .) The upper layers of the sealing member  200  comprise an upper PET layer  202  bonded to a lower EVA (ethylene-vinyl acetate) layer  204 . The lower layers comprise an aluminum foil layer  210  which is bonded to a PET layer  212  which in turn is bonded to a hot melt bonding material or adhesive layer  322 . This design adds a PE (polyethylene) foam layer  208  over the upper surface of the aluminum foil layer  210 , as is illustrated in  FIG. 2  (which corresponds to FIG. 3 of the &#39;926 patent). The EVA layer  204  is heat bonded to the new PE foam layer  208  in the left half of the sealing member  200 , as is shown. To the right, a release strip  206 , made of PET, is coated on its underside with a silicon release coating to prevent the strip  406  from sticking to the PE foam layer  208 . The PET release strip  206  and the PET upper layer  202  sandwich the left half of the EVA layer  204  to a release tab. The EVA layer  204  and the PE foam layer  208  are heat bonded together. 
     Several patents teach the incorporation of holographic film into various types of seals for packages and containers. Such holographic sealing members enable counterfeit products to be identified and also signal, by their condition when the seals have previously been tampered with. 
     Once such Holographic seal is disclosed in U.S. Pat. No. 5,319,475, which issued to Ralph Kay, et al. on Jun. 7, 1994. This patent discloses a package sealing tape having a layered structure. Its upper layer is a removable layer formed from polypropylene or polyester film, smooth and transparent. This upper layer is loosely adhered (by means of wax or corona discharge treatment) to a much thinner, transparent polymer layer. The polymer layer is bonded to an embossable lacquer layer formed from non-cross-linkable polyurethane or polyester. This layer is embossed to define a hologram, and then a metallic film, such as aluminum, is deposited upon this layer and is optionally coated with a polymeric coating. The lowest layer is a pressure sensitive transfer adhesive bound to release paper. In use, the release paper is removed, and then the tape is used to seal a container. The upper layer is scuff resistant, so it may be left on during transit to protect the hologram. It may also be removed. In the face of solvents or heat, the embossable layer and its hologram is quickly and irreversibly damaged, thus making a permanent record of the attempt at tampering with the package. A similar arrangement is disclosed in U.S. Pat. No. 6,659,507, issued to Michael Banahan, et al. on Dec. 9, 2003, which also provides an additional fluorescent pattern visible only under ultraviolet light and a mechanism that breaks up the hologram if the layers are separated. 
     U.S. Pat. No. 7,012,032, which issued to Steven R. Consentino, et al. on Mar. 14, 2006, discloses in FIG. 3 of the &#39;302 patent a holographic image (col. 7, lines 20-34 of the &#39;032 patent) applied as the top layer in a laminated sealing member for a “bottle type container” with an upper PET layer, an intermediate thermal bonding polymer layer (a co polyester resin), and a lower woven or non-woven reinforcing scrim polymer layer (polyester such as PET) beneath which is an adhesive layer. In its “Background” portion, the &#39;302 patent says: “seals and lids can be constructed to have a tab that extends outwardly from the periphery of the seal so that a user can grasp the tap to aid in removing the seal from the container.” (&#39;032 patent, col. 1, lines 37-40) FIG. 3 of the &#39;032 patent discloses a tab 33 that is somehow attached to, and extending outwards from, the periphery of the lowest adhesive layer. The text accompanying this figure says: “Preferably the seal contains a small tab to facilitate removal.” Nothing more is said about this tab. 
     U.S. Pat. No. 4,892,209, which issued to Jan L. Dorfman, et al. on Jan. 9, 1990, discloses a liquor bottle capping assembly which includes a sealing member that comprises two parts: First, a lower circular disk, made of aluminum or “high durometer plastic” or some other material sufficiently strong to resist and/or provide evidence of penetration by a hypodermic needle; and second, an upper circular sheet member 26 that is adhesively laminated to the lower circular disk 60. The upper circular sheet member may be made of metal foil and may carry a laser-imprinted hologram obtained from American Bank Note Holographics, Inc. Alternatively, the circular disk 80 may be constructed from plastic film, metallised plastic, or some other material that will provide evidence of any tampering. The upper circular sheet member initially has a figure-8 shape, and it is folded back upon itself to form joined upper and lower circular portions, the lower circular portion forming the circular sheet member itself, and the upper circular portion forming a removal tab of slightly smaller diameter, as is illustrated in FIGS. 1 and 2 of the &#39;209 patent. 
     SUMMARY 
     An embodiment of the present invention can be found in a holographic sealing member for a container that comprises a heat actuated sealant or adhesive layer that secures the sealing member to a container, a metal foil sealing layer over and covering and adhesively bonded to the heat actuated sealant or adhesive layer means, a holographic layer over and covering and adhesively bonding to the metal foil layer having an upper plastic layer and a lower embossed image layer, and a tab over and covering and adhesively bonded to the upper plastic layer that may be pulled to remove the tab and the plastic layer from a container, thereby exposing the lower embossed image layer which must then be perforated to gain access to the contents of the container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  each present a cross-sectional side view of a prior-art laminated sealing member having a removable tab structure facing to the right. The vertical dimensions are exaggerated and are not drawn in proportion to the actual vertical dimensions of each layer of the sealing member. (Cross-sectioning lines are omitted from some layers for clarity.) 
         FIG. 3  presents a cross-sectional side view of a laminated sealing member having a removable tab structure facing to the right, the sealing member shown attached to the mouth of a container. The vertical dimensions are exaggerated and are not drawn in proportion to the actual vertical dimensions of each layer of the sealing member. (Cross-sectioning lines are omitted from some layers for clarity.) 
         FIG. 4  presents a cross-sectional side view of the laminated sealing member shown in  FIG. 3  following removal of the tab and the layers attached to the tab, the lowermost layers of the sealing member shown still attached to the mouth of the container. 
         FIG. 5  presents a cross-sectional side view of a laminated sealing member in accordance with an embodiment of the invention having a removable tab structure facing to the right. The vertical dimensions are exaggerated and are not drawn in proportion to the actual vertical dimensions of each layer of the sealing member. (Cross-sectioning lines are omitted from some layers for clarity.) 
     
    
    
     DETAILED DESCRIPTION 
     A sealing member  500 , designed in accordance with a first embodiment of the present invention, is illustrated in  FIG. 5 .  FIG. 5  is described in several later paragraphs. The immediately following paragraphs describe  FIGS. 3 and 4 , which describe a related invention. 
       FIG. 3  presents a side, cross-sectional view of the sealing member  300  and of the upper, circular rim of a PET container  324  to which the sealing member  300  is sealed by induction heating of an aluminum layer  310 , which melts the hot melt bonding material or adhesive layer  322  and binds the sealing member  300  to the circular rim of the container  324 . (Note that the cross sectioning lines have been omitted from the layers  302 ,  304 ,  308 ,  310 ,  307 , and  309  in  FIG. 3  and are shown in the urethane adhesive layers  318  and  320  and hot melt bonding material or adhesive layer  322 .) 
     The structure of the sealing member  300  ( FIG. 3 ) is essentially the same as that of the sealing member  200  ( FIG. 2  described above) except that the lower PET layer  212  in  FIG. 2  has been replaced in  FIG. 3  with a holographic film comprising a PET layer  307  bonded to a embossed image layer  309  which bears a holographic image and which has an aluminum substrate. The layer  309  in its turn is bonded by the hot melt bonding material or adhesive layer  322  to the land area of the container  324  (the land area of the container  324  is the uppermost, ring-shaped upper surface of the circular upper rim of the container  324 ). The PET layer  307  and the embossed image layer  309  are bonded together in such a manner, and with such a bonding strength, that the layers  307  and  309  are separable along their periphery—the bond at a splitting point  311  is not as strong as the bond formed by the layer  322  between the layer  309  and the container  324 . 
     Accordingly, when the tab formed by the layers  302 ,  304 , and  306  is pulled, all of the uppermost layers  302 ,  304 ,  308 ,  310 , and  307  of the sealing member  300  are pulled away along with all save a thin peripheral ring of the embossed image layer  309 , leaving only a thin peripheral ring  309 A (see  FIG. 4 ) of the embossed image layer  309  sealed by means of a thin ring of the hot melt bonding material or sealing layer  322 A to the land area of the container  324 . 
     Accordingly, a circular ring of the embossed image layer  309 A remains bonded to the land area of the container  324  after the sealing member  300  is removed. Thus, a thin ring of the hologram which the embossed image layer  309 A carries remains attached to the upper lip of the container  324 , while the remainder of the embossed image layer  309  is peeled away and is removed from the container  324  and is separated from the circular ring portion  309 A of the layer  309 . Hence, removal of the tab (formed by the layers  302 ,  304 , and  306 ) necessarily produces destruction of the hologram such that the holographic seal borne by the embossed image layer  309  is tom through and can never be reassembled and reattached to the container  324 . 
     The sealing member  300  is thus entirely removed in a single motion, but the ring portion  309 A of the embossed image layer  309  remains behind, attached to the land area of the container  324 , tom away from the remainder of the embossed image layer  309  in a way that destroys the hologram and makes it impossible to re-seal the sealing member  300  back onto the container  324 . After the sealing member  300  is removed from the container  324 , the holographic image is visible on the top side of the rim of the container  324 . It is not possible to reseal the container. 
     The bonding of the PET layer  307  to the embossed image layer  309  is carefully controlled to set the amount of adhesion that exists between the PET layer  307  and the embossed image layer  309 . This bonding strength must be low enough so that when force is applied to the tab formed by layers  302 ,  304 , and  306 , the sealing member  300  splits at the splitting point  311  around the periphery of the sealing member  300  but only above the land area of the container  324 , thus permitting most of the embossed image layer  309  to be ripped away still attached to the layers  302 ,  304 ,  306 , and  307  but leaving behind the ring portion  309 A of the embossed image layer  309  attached to the land area of the container  324 , as is shown in  FIG. 4 . PET holographic film produced by American Bank Note Holographics (ABNH) works well in this application. A product could be designed that would function in the same manner if the holographic film was modified to contain some type of release layer between the PET film layer  307  and the embossed image layer  309 . The PET film produced by ABNH has proved (in its normal, unmodified form) to have a structure that functions properly. 
     The PET layer  307 , the embossed image layer  309 , and the bond between them are preferably chosen to be relatively heat insensitive so that overheating by inductive heating of the hot melt bonding material or adhesive layer  322  does not adversely affect the amount of effort that is required to remove the sealing member  300 . In conventional designs, such as that shown in  FIG. 2 , it is the seal between the container (not shown in  FIG. 2 ) and the entire sealing member  200  that must be broken, and the amount of effort that is required to remove the sealing member  200  can be adversely affected by overheating during the inductive heat sealing of the sealing member  200  to a container. The ABNH PET holographic film is relatively insensitive to heat variations, as is explained more fully in a later paragraph. 
     In another embodiment of the invention illustrated in  FIGS. 3 and 4 , two American Bank Note Holographics, Inc. films are included in the same structure. The structure is the same as described in  FIGS. 3 and 4  with the addition of a second holographic film that is laminated between the aluminum foil layer  310  and the holographic film layer (layers  307  and  309 ) which is coated with the heat actuated coating (the layer  322 ). In addition, gold pigmentation is added to the adhesive layer between the two holographic film layers. When separation of the layer  322  and the metal and holographic embossed image layer  309  from the PET layer is invoked upon removal of the sealing member  300 , the holographic ring  309 A from the primary holographic layer remains on the rim of the PET container  324 , and the uncovering of the area where this ring separates from the primary seal exposes the secondary holographic film that appears in gold because of the added pigmentation. This leaves a portion of a holographic image on the container rim and another portion on the removed sealing member  300  components. 
     The heat activated hot melt bonding material or adhesive layer  322  in  FIG. 3  is a polyester heat seal coating 40-3 obtainable from Rohm and Haas. This heat actuated coating is applied to the metallic side of metallised holographic film (comprising the PET layer  307  and the embossed image layer  309  which includes a metal layer formed from aluminum). The PET side ( 307 ) of the holographic film is laminated and adhered to an aluminum foil layer  310 . Above this foil layer  310  an optional insulating layer  308  (polyethylene foam in  FIG. 3 , for example) can be applied, and polyethylene, polypropylene, or polyester may be applied above this insulating layer, or these materials may be applied directly to the foil layer if the optional insulating layer  308  is absent. A tab defining PET release strip  306  is placed over and covers at least a portion of the foil layer  310  or insulating layer  308 . An EVA or adhesive layer  304  lies above the PET release strip  206  and is covered by a PET layer  302  to form the tab that is used to remove the sealing member  300  from the rim of the container  324 . The splitting or separation point  311  occurs within the holographic film layer. Because the embossed image layer  309  is thin and is bonded firmly to the rim of the container  324 , in this case a PET container  324  to coincide with the PET heat seal coating (the hot melt bonding material or adhesive layer  322 ), the upper liner is completely removed from the rim, leaving the PET heat seal coating layer  322 A and the metal and image layer  309 A only on the rim of the container  324 . A strong bond is desired between the layer  322  and the upper lip of the container  324  to firmly attach the ring of embossed image layer  309 A to the upper lip of the container  324 . Some other heat seal coating can be selected that can provide a seal to other types of containers—for example, a polypropylene heat seal coating or a polyethylene heat seal coating can be used with a container made of those materials. It may also prove feasible to extrusion coat the metal side of the holographic film with a suitable polymer film as thin as 0.5 mils that would provide the desired splitting and adhesion in the rim area of the container  324 . 
     With reference to  FIG. 5 , the present invention is illustrated embodied in a sealing member  500 . (Once again, the cross sectional lines are omitted from the layers  502 ,  504 ,  506 ,  508 ,  507 ,  509 , and  510  in  FIG. 5  for clarity and are shown in the urethane adhesive layers  516 , and  518  and hot melt bonding material or adhesive layer  522 .) 
     The sealing member  500  is similar to the sealing member  200  shown in  FIG. 2 , but the polyester foam layer  208  shown in  FIG. 2  is replaced by a white PET layer  508  that is bonded to a holographic film formed by the combination of a PET layer  507  with an embossed image layer  509  that includes a metal (aluminum) layer, the layers  507  and  509  being bonded together in a manner such as to form a splitting point  511  that gives way then the layers  502 ,  504 , and  506  are pulled. The splitting point  511  is thus within the holographic film structure, between the image layer  509  and the PET layer  507 . The urethane adhesive layer  518  binds the metal and embossed image layer  509  to the upper surface of the adhesive coated (adhesive layer  522 ) aluminum foil layer  510 . The adhesive layer  522  is an easily punctured film such as MDPE (medium density polyethylene) 1.5 mils in thickness, obtainable from Covalence Specialty Materials Corporation. This design allows the holographic embossed image layer  509  and aluminum film layer  510  to be destroyed easily by puncturing through these two layers. In this design, there is no PET acid barrier layer beneath the two layers  509  and  510 , since such a layer would be difficult to penetrate with a finger. Other easily-punctured films, such as a NEX (a trademark of New England Extrusion, Inc.) sealant having an EVA content or SURL YN (a trademark of DuPont for a particular DuPont thermoplastic ionomer resin product), etc., may be used to form the layer  522 . 
     The strength of the bond between the layers  507  and  509  is chosen to cause the sealing member  500  to split apart at  511  when the tab formed by the layers  506 ,  504 , and  502  is pulled upwards and to the side. Accordingly, when the tab formed by the layers  506 ,  504 , and  502  is pulled, the sealing member  500  splits apart at the splitting point  511 , uncovering the hologram which is visible in the embossed image layer  509  and leaving in place the seal formed by the aluminum layer  510  that is bonded to the embossed image layer  509 . 
     After removing the upper layers  502 ,  504 ,  506 ,  508 , and  507  of the sealing member  500  by pulling on the tab formed by the layers  506 ,  504 , and  502 , an individual wishing to access the container (not shown) must then pierce the remaining layers  509  and  510 , thus breaking the holographic seal over the container. Hence, the seal on the container cannot be broken without the simultaneous destruction of the hologram. 
     This design again uses ABNH PET holographic film. The chemistry of the image layer of this product supports heat resistance for the image. The image layer is highly cross-linked, and this gives the film superior heat resistance and also explains why the bond between the layers within the holographic film tend to be relatively weaker. Many holographic films do not have this heat resistance, especially if the image is cast on a polypropylene film. Since induction container sealing can produce temperatures that can be in the range of 350 to 450 degrees Fahrenheit, if the holographic film technology does not possess adequate heat resistance, then the image or film or both would become distorted during induction heating, particularly when excessive heating is applied. 
     By removing, separating, or splitting the PET layer away from the image layer, the image of the hologram remains undisturbed and completely legible above only an easily pierced layer of foil and sealant and can be destroyed by simply puncturing it with a finger. If the PET layer were not stripped away when the tab layers were pulled away, then the PET layer would need to have sufficient heat stability, and it would also have to maintain the integrity of the image layer. It would be difficult to puncture through the lining of such a structure. 
     An alternative arrangement omits the white PET layer  508  and the bonding material  516  and has the EVA layer  504  bonded directly to the PET layer  507 . 
     While several embodiments of the invention have been described, numerous alternatives will occur to those skilled in the art. The claims appended to and forming a part of this patent application are intended to cover all such alternatives that fall within the true scope of the invention.