Abstract:
An adhesive label for application upon a circumferential surface of a dry cell battery  50  having an axis and cover- and bottom-surfaces  51, 51  includes: a stretched, shrinkable, transparent cover foil with a top side and a bottom side, an imprint located beneath the cover foil visible from the top side and a contact adhesive layer located beneath the imprint, wherein the adhesive label  1  comprises first edge segments  19, 19  along a generation line of the circumferential surface of the battery  50  which can be superimposed in an overlapping manner and second edge segments  17, 17  projecting axially beyond the end surfaces  51, 51  of the battery, which end segments  17, 17  rest upon the end surfaces  51, 51  by shrinkage of the cover foil, wherein the imprint is applied directly upon the bottom side of the cover foil.

Description:
BACKGROUND OF THE INVENTION 
     The invention is directed to an adhesive label for application upon a circumferential surface of a dry-cell battery having an axis and top- and bottom-surfaces, comprising a stretched, shrinkable, transparent cover foil with a top side and a bottom side and an imprint visible from the top side located beneath the cover foil and a contact adhesive layer located beneath the imprint wherein the adhesive label comprises along a generating line of the circumferential surface of the battery first edge segments superimposable in an overlapping fashion and second edge segments protruding or projecting beyond the end surfaces of the battery, which rest upon the end surfaces due to shrinking the cover foil thereon. 
     The cover foil provides protection for the battery against leakage and furthermore protects the label layers located beneath same, in particular the imprint, from mechanical damage. In addition the cover foil insulates the circumferential surface of the battery electrically against the environment. If a layer beneath the cover foil is electrically conductive, the cover foil insulates also this layer against the environment. Various adhesive labels of this type are known from the DE 33 42 309. These conventional adhesive labels are produced in such a way, that several layers partially from shrinkable foil are applied on a carrier layer located at the bottom in the finished label, with the topmost of these layers being provided with an imprint. The cover foil must then be fastened to the label material carrying the imprint. In order for the cover foil to adhere to the imprint, it is necessary to apply beforehand a separate laminating adhesive layer upon the imprint. The laminating adhesive must satisfy particularly high requirements, in view of the adhesive label fulfilling its function of protecting against leakage, being non-fading as well as durable in storage. 
     SUMMARY OF THE INVENTION 
     It is thus the aim of the invention to specify an adhesive label of the above-mentioned type, which can be manufactured more simply particularly by a different method. It should be especially possible to meet the different requirements of different battery embodiments by a greater variability of the build-up of the layers. 
     In order to solve this task, the imprint is applied in the invented adhesive label directly to the bottom side of the cover foil. 
     Differing from the above mentioned known adhesive labels, the build-up of the different layers of the adhesive layer proceeds from the cover foil. The printing is applied directly to the cover foil. The imprinted cover foil can in further fabrication steps be placed upon a composite succession of previously prepared label layers, preferably however the additional layers are consecutively placed upon the cover foil carrying the imprint. One single shrinkable foil, the cover foil, is sufficient. Preferably a layer is placed upon the imprint-free partial surfaces of the cover foil, which again carries the contact adhesive layer on its other side. This layer provided with the contact adhesive can exhibit a prevalent carrier function for the label material or, however, it can assume a carrier function subordinate to the cover foil. 
     The layer carrying the contact adhesive can rest directly upon the imprint and upon the partial surfaces of the cover foil not covered by the imprint. Depending upon the material combination selected, the adhesive connection between the layer carrying the contact adhesive and the cover foil could be insufficient under unfavorable conditions. It is preferred for this case to apply, preferably thermosensitively, a transparent primer layer upon the imprinted cover foil and upon this transparent primer layer to then apply the layer carrying the contact adhesive. 
     The layer carrying the contact adhesive can be formed from non-metallic materials, as for instance paper or plastics, wherein it is preferred that this is limited to the partial surfaces of the adhesive labels with exception of the first border segments and thus corresponds exactly to the length of the circumferential surface of the battery. Alternatively the carrying layer can be formed also from metallic material, in particular by a layer applied by aluminum vapor deposition in a vacuum. The material selection depends on the desired appearance of the label from the outside, since the layer carrying the contact adhesive constitutes a background for the imprint visible from the outside. 
     Furthermore, the layer carrying the contact adhesive can be formed by a composite arrangement of a bottom non-metallic partial layer, in particular paper and a metallic partial layer especially from aluminum foil resting on same; said metallic partial layer is herein preferably limited to the partial surfaces of the adhesive label excluding the second border segments and thus corresponds exactly to the height of the battery cylinder of the battery. This version results in an appealing background for the imprint and a particularly thin aluminum foil can be used herein, without affecting the thickness of the adhesive label, in particular, when a cover foil dimensioned to be very thin is used. 
     Preferably, the metallic partial layer is applied to the non-metallic partial layer as a foil by the foil transfer method, meaning it is vapor-deposited or sputtered upon same. 
     In another particularly simple to manufacture embodiment, the contact adhesive layer lies directly upon the imprint and upon the partial surfaces of the cover foil devoid of the imprint. The layer carrying the contact adhesive in the above embodiments is eliminated. The cover foil is in this case the sole firm layer of the label and it alone assumes the carrier function. This embodiment can be manufactured to be particularly thin because of the low quantity of the layers, wherein the space, subject to standards specified for the dry cell battery, for filling same becomes larger. 
     The imprint is preferably printed upon the cover foil in colors from organic solutions or photocatalytic system without solvents by the mirror image action and reverse printing, meaning from below directly upon the cover foil in a mirror image manner, so that the imprint can be seen on the correct side from the top. These color systems are particularly suited for imprinting the shrinkable foil without changing or exfoliating in the course of the shrinkage process. Furthermore, they have the electric characteristics required for dry-cell batteries and are resistant to chemicals, which is particularly important in view of the leakage protection function of the battery label. 
     The cover foil is preferably made from shrinkable hard polyvinyl chloride, polypropylene, polystyrol, polyamide, particularly of a thickness of 25 to 60 micrometers or of polyethylene terephthalate or of polycarbonate, in particular of a thickness of 10 to 60 micrometers. So that the adhesive label after being shrunk upon the battery, adheres as firmly as possible and so that the adhesive label does not peel off the body of the battery also when subjected to unfavorable environmental conditions, the cover foil is stretched in circumferential direction of the dry-cell battery, so that the adhesive label has the greatest pre-stressing in circumferential direction after being shrunk on. 
    
    
     The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 Shows diagrammatically the application of an adhesive label upon a cylindrical body of a dry-cell battery. 
     FIG. 2 Shows a first embodiment of an adhesive label in cross section. 
     FIG. 3 Shows a second embodiment of an adhesive label in cross section. 
     FIG. 4 Shows a third embodiment of an adhesive label in cross section, 
     FIG. 5 Shows a fourth embodiment of an adhesive label in cross section, 
     FIG. 6 Shows a fifth embodiment of an adhesive label in cross section, 
     FIG. 7 Shows a sixth embodiment of an adhesive label in cross section, 
     FIG. 8 Shows a seventh embodiment of an adhesive label in cross section, and 
     FIG. 9 Shows an eighth embodiment of an adhesive label in cross section. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 2 shows a diagrammatic section through a first embodiment of an adhesive label. In the course of fabrication a cover foil  3  from stretched, shrinkable, transparent foil from hard PVC (polyvinyl chloride), PP (polypropylene), OPP (oriented polypropylene), PET (polyethylene terephthalate), PS (polystyrene), PE (polyethylene), PC (polycarbonate), or polyamide with a thickness of 20 to 70 micrometers is provided directly on the bottom side with an imprint  5  visible from the outside. When a PET- or a PC-foil is used, thicknesses of 10 to 60 micrometers are preferred. 
     In case of using a PP-, OPP-, PS- or PE-foil by way of a cover foil  3 , the cover foil, in view of the unpolarized properties of the foil material, is provided prior to application of the imprint  5  with an adhesion imparting primer layer  3   a  of a thickness of approximately 2 micrometers as a imprint adherence improvement agent. The primer layer  3   a  increases the surface tension. 
     In order to make the imprint  5  adhere to the cover foil  3  in a satisfactory manner also without a primer layer  3   a,  it is possible to polarize the cover foil  3  in the high frequency field with formation of caboxyle (corona treatment). The cover foil  3 , the primer layer  3   a  and the imprint  5  are permanently resilient, so that the label can also be shrunk upon the battery, even if kept in storage for several months, without the imprint  5  detaching itself from the cover foil  3 . The cover foil  3  is the only shrinkable plastics foil layer of the adhesive label. It can carry additional layers on the top and bottom side. The imprint  5  and those partial surfaces of the cover foil  3  not carrying the imprint are covered by a metal layer  7  particularly from aluminum using a vapor deposition or a sputtering method. The metal layer  7  forms a background for the imprint  5  visible from the outside and is electrically insulated against the outside by the cover foil  3 . A non-metallic layer  9  from plastics foil or paper is applied upon the bottom side of the metal layer  7 . The metal layer  7  and the non-metallic layer  9  together form a carrier material  11  of the label  1 . 
     Alternatively the metal layer  7  can be applied upon the non-metallic layer  9  separately from the cover foil  3 , possibly it can be vapor-deposited or sputtered thereon, and the carrier material  11  resulting from these two partial layers  7 ,  9  is fastened, possibly by means of a primer layer, upon the imprinted bottom side of the cover foil  3 , in particular by the application of heat. 
     The carrier material involved is provided with contact adhesive  13  on its bottom side, and thus the finished label  1  is placed upon an adhesion repellent, possibly siliconized, carrier band or tape  15 , from which it is later transferred to a battery body by a dispensing device not shown here. 
     FIG. 2 shows the imprint  5  only diagrammatically with intermediate spaces. 
     In this, as in all subsequently described embodiments, the imprint  5  can, however, also be an area closed in itself, multi-colored, multi-layered, a combination of non-transparent printing colors and/or opaque printing colors. Special metal colors, thus also particles of an area wide vapor deposition brought into solution, also form a particularly closed in itself colored layer. 
     FIG. 1 shows diagrammatically the application of the adhesive label  1  upon a cylindrical battery body  50  of a rechargeable or non-rechargeable dry cell or appliance battery. The adhesive label  1  is placed with its contact adhesive layer  13  upon the circumference of the battery body  50  in such a way, that its longitudinal edges  17 , not imprinted upon and having no carrier material  11 , protrude beyond the end-surfaces  51 ,  51  of the battery body  50 , wherein in particular the stretching direction of cover foil  3  runs in circumferential direction of the battery body  50 . Then the adhesive label  1  is placed around the circumference of the battery body  50 , so that the end regions  19 ,  19  of the adhesive label  1  overlap one another. Subsequently, the adhesive label is shrunk upon the battery body  50  by application of heat, so that the longitudinal edges  17  rest upon the end surfaces  51 ,  51  of the battery body  50  and additionally adhere to the end faces  51 ,  51  due to the contact adhesive  13 . Due to the overlapping end regions  19 ,  19  and the longitudinal edges  17  resting upon the end surfaces of the battery body  50 , the adhesive label encapsulates the battery body  50  and provides, in addition to the electric insulation of the cell, a protection against leakage. The externally located cover layer  3  protects the layers located beneath it from damage, in particular during the fabrication process of the battery beginning with the application of the label up to the packaging of the finished battery and resists also mechanical stresses in battery layers of the appliances being used. 
     FIG. 3 shows a second embodiment of the adhesive label  1 . It differs from the version shown in FIG. 2 in that the carrier material  11  is a single layer. If the carrier material  11  is from metal, such as possibly aluminum, it can be vapor-deposited or sputtered upon the imprinted bottom side of the cover foil  3 , possibly at a thickness of 2 to 7 Å. Alternatively, the metal layer  11  can be applied to a carrier not shown here, separately from the cover foil  3 , from which carrier it is then transferred by means of a thermo-sensitive intermediate layer upon the imprint  5 . This carrier represents preferably a foil acting as a system-conditioned assist means, which is pulled off after the transfer of the metal layer and is subsequently rolled up, thus no longer participating in the buildup of the layers. The contact adhesive  13  is applied directly upon the metal layer  11 . Here also the cover foil  3  can, if necessary, be provided with a primer layer  3   a  or subjected to a high frequency treatment prior to the imprinting process. 
     FIG. 4 shows a third embodiment of the adhesive label  1  similar to FIG. 3 having a single layer carrier material  11 . The carrier material  11  consists of paper or plastics and is placed upon the imprinted bottom side of the cover foil  3  by means of a laminating adhesive layer  21  located in between. The laminating adhesive layer  21  is applied as a lacquer or glue in a liquid or semi-liquid phase and is cured or hardened by chemical reaction of the binder and the hardener component parts, by irradiation and/or by release of solvents. The laminating adhesive layer  21  can be pigmented in case of an imprint which is not closed in itself area-wise and can constitute an optical background for the imprint  5 . The laminating adhesive layer  21  improves the adhesion of the carrier material  11  upon the imprinted bottom side of the cover foil  3 . The laminating adhesive layer  21  has a thickness of 3.5 to 5 micrometers corresponding to 2.5 to 4 grams per meter square and forms a barrier against diffusion of solvents from the contact adhesive layer  13  located beneath same into the imprint and thereby its changing if kept in storage for a long time. The laminating adhesive layer  21  is an additional barrier against migrations of electrolyte and improves at the same time the electrical insulation properties of the label, without having to use an additional insulation layer. In this case also, the cover foil  3  can, if needed, be provided with a primer layer  3   a  prior to imprinting or it can be subjected to a high frequency treatment. 
     FIG. 5 shows a fourth embodiment. As in previous embodiments an imprint  5  is directly provided to the cover foil  3  on its bottom side. Differing from the above versions, no separate carrier layer follows thereon, rather, the contact adhesive layer  13  is directly applied upon the imprinted bottom side of the cover foil  3 . The cover foil  3  assumes here the sole carrier function for the adhesive label. The imprint  5  can be closed in itself area wise, so the surface of the battery body located beneath it is not visible. The imprint  5  improves the electric insulation of the label and prevents a diffusion of solvents from the contact pressure layer  13  or from electrolyte residues on the battery surface. The contact pressure layer  13  can be colored and forms then an optical background for an opaque imprint which is not closed in itself area wise. Here also, the cover foil  3  can if needed, be provided with a primer layer  3   a  prior to imprinting same or can be subjected to a high frequency treatment. 
     FIG. 6 shows a fifth embodiment similar to FIG. 5, whose imprint  5  carries however a laminating adhesive layer  21  on its bottom side similar to the one in FIG.  4 . The laminated adhesive layer  21  is applied as a lacquer or glue in a liquid or a semi-liquid phase and hardens in a chemical reaction of binder-and-hardner components by irradiation and/or by a release of solvents. The laminating adhesive layer  21  can be pigmented in case the imprint is not closed within itself area wise and can form an optical background for the imprint  5 . Furthermore, the laminating adhesive layer  21  also fulfills the function of a barrier against diffusion of solvents from the contact adhesive layer  13  applied on the bottom side of the laminating adhesive layer  21  or from electrolytes upon the surface of the battery body into the imprint  5  and protects said imprint from changes. This improves the durability of adhesion and the storage endurance of the label also under unfavorable conditions, such as high temperature and humidity. Here also the cover foil  3  can be provided with a primer layer  3   a  if needed prior to imprinting same or be subjected to a high frequency treatment. 
     FIG. 7 shows a sixth variant. The cover layer  3 , the primer layer  3   a  possibly present in case of an unpolarized foil and the imprint  5  correspond to the version in FIG. 3. A laminating adhesive layer  21  corresponding to the embodiment in FIG. 4 is applied upon the imprint  5  and the partial surfaces of the cover layer  3  devoid of said imprint. 
     The laminating adhesive layer  21  improves the adhesion of a metal layer  7  placed upon same, for instance from aluminum corresponding to the version in FIG.  3 . This metal layer  7  is sputtered or vapor-deposited at a thickness of 2 to 7 Å. Because of the micropartial accumulation or superposition of metal particles, the metal layer  7  is porous and has a clearly higher electrical resistance than metal foil. The metal layer  7  covers additionally unavoidable contaminations and stains upon the battery body  50 . 
     Alternatively the metal layer  7  can be also be transferred as a foil to the laminating adhesive layer  21  by the transfer method. Herein, a metal foil  7  adhering to its proper carrier tape is placed upon the more firmly adhering laminating adhesive layer  21 . Then the carrier tape having a low adhesion is pulled off the metal layer firmly adhering to the label material. 
     The laminating adhesive layer  21  constitutes a resilient connection between the metal layer  7  and the cover foil  3 . This resilient connection prevents the metal layer from being distorted during shrinkage of the foil and in the course of labeling upon narrow radii of the battery body. The resilient connection absorbs shearing forces and warping in the label. At the same time, the resilient connection forms the barrier described previously in connection with FIG. 4, which prevents solvents from the contact adhesive  13 , which can have penetrated into the pores of the metal layer  7 , from diffusing into the imprint and changing same, as well as considerably improving the electrical insulation. The laminating adhesive  21 , which has penetrated into the pores of the metal layer, hardens or cures said metal layer. 
     The laminating adhesive layer  21  can be a lacquer which, after being applied in liquid or semi liquid state, is hardened or cured by a chemical reaction of the binder and hardner component parts, irradiation and/or by perspiration of solvents. Prior to sputtering or vapor depositing the metal layer  7 , it is possible to permit the laminating adhesive  21  to cure or harden. In case of the superposition of a metal foil, possibly by the foil transfer method, it is possible to place the metal foil on the not yet cured or hardened laminating adhesive layer  21 , in order to utilize the adhering effect of the not yet cured lacquer. The laminating adhesive layer  21  can contain pigments for formation of an optical background for the imprint  5 . 
     The contact adhesive layer  13  has, just as in the previous versions, a thickness of 10 to 25 micrometers and insulates the metal layer  7  electrically against the battery body  15 . In case of using the laminating adhesive layer  21 , the contact adhesive layer  13  can be thinner than 15 micrometers, since the laminating adhesive layer  21  has also insulating properties. 
     The contact adhesive  13  which has penetrated into the pores of the metal layer  7  insulates the pores and increases thus the electrical resistance of the metal layer  7 . 
     The adhesion of the individual label layers must be arranged in such a way in the overlapping region  19  (FIG. 1) of the adhesive label, that, with the label placed upon the battery body  50 , the stress in the shrunk cover foil  3  does not rip the laminating adhesive layer  21 . 
     The laminating adhesive layer  21  is preferably a two-component adhesive or—lacquer including a binder and hardener, and the contact adhesive  13  represents as a rule a permanently resilient single component adhesive with stabilizers such as antioxidants, which prevent a hardening or curing and with this spalling as a result of an area rupture with a simultaneous high shear force in the contact region. Thereby, the laminating adhesive layer  21  adheres in the hardened state more strongly than the not hardened one and therefore permanently resilient contact adhesive  13 . The adherence effect of the contact adhesive  13  in the overlapping region  19  of the cover foil  3  is adapted to the adhesive effect to the battery body  50  between the overlapping regions in such a way, that bursting of the overlap  19  is prevented. 
     FIG. 8 shows a seventh version, which differs from the version in FIG. 7 as far as the layer buildup between the imprint  5  and the metal layer  7  is concerned, otherwise, however, is identical to the version shown in FIG. 7 with all its embodiment variants. 
     The laminating adhesive layer  21  applied to the imprint  5 , which can correspond in its component parts to the version in FIG. 7, is resilient and forms a resilient connection between the cover foil  3  and the metal layer  7 , so that said metal layer  7  is not damaged, possibly undulates or tears apart in the course of shrinking the cover foil  3  upon the battery body. This resilient connection absorbs shearing forces and warping in the label. The laminating adhesive layer  21  adheres more strongly than the contact adhesive  13 . 
     A lacquer layer  22  is applied on the bottom side of the laminating adhesive layer  21 , which lacquer layer  22  is harder and/or more dense than the laminating adhesive layer  21  and which assumes the barrier function described in connection with FIG. 7 against diffusion of solvents from the contact adhesive layer  13  or from electrolytes on the battery surface into the imprint  5 . It is easy to sputter or vapor-deposit metal upon the lacquer layer  22  because of its strength and the thus treated lacquer layer  22  prevents passage of such solvents from the contact adhesive layer  13  and of electrolytes on the battery surface, which have already penetrated through the pores in the metal layer  7 . 
     The laminating adhesive layer  21  and/or the lacquer layer  22  can be pigmented and can form an optical background for the imprint. 
     FIG. 9 shows an eighth version similar to FIGS. 7 and 8, however, with a modified laminating adhesive layer  21  which as far as its component parts are concerned can be configured to correspond to the embodiment shown in FIG.  7 . The laminating adhesive layer  21  is applied upon the imprint  5  in a liquid or semi-liquid state and is subsequently partially cured or hardened in such a way by curing or hardening of the binder and the hardener shares by radiation and/or perspiration of solvents, that a resilient partial layer  21   a  resting upon the imprints and a harder partial layer  21   b  remote from the imprint  5  is formed, upon which subsequently the metal layer  7  can be very easily sputtered or vapor-deposited. The resilient partial layer  21   a  serves as a resilient connection between the cover foil  3  and the metal layer  7 , with the effect of the laminating adhesive layer  21  in the embodiment shown in FIG. 8, and the harder partial layer  21   b  forms the barrier layer with the effect of the lacquer layer  22  in the version shown in FIG. 8 against diffusion of solvents from the contact adhesive layer  13  and of electrolytes on the battery surface through the pores in the metal layer  7  into the imprint  5 . A laminating adhesive layer  21  and/or the lacquer layer  22  can be pigmented for formation of an optical background for the imprint  5 . 
     A plurality of adhesive labels adheres detachably to a siliconized carrier band or tape  15 . 
     While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.