Abstract:
A pressure sensitive label has a water dispersible adhesive as the bottom functional layer adjoining a container wall or other surface. A variety of as-manufactured structures are disclosed including ones in which one or more layers of the as-manufactured structure may be removed prior to adherence to a surface and ones which may be rolled up into a roll.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is based upon and claims the benefit of Provisional Patent Applications Ser. Nos. 60/454,221 filed Mar. 13, 2003 and 60/515,466 filed Oct. 29, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention is directed to a multilayer pressure sensitive adhesive label having a water dispersible adhesive as the bottom functional layer adjoining a container wall or other surface. Although the label of the present invention may be used with a container intended for packaging goods for extended periods of time, it is particularly well suited as a label applied to a pan or other type of container from which foods in a restaurant may be served. One embodiment will be described specifically as it relates to use in a food rotation application where, after a predetermined length of time in which the food has been in a serving container, it will be deemed to have passed beyond the safe useable length of time in such serving container and will be discarded. At that time, it is desirable that the label be readily removable from the container in order that such container can be washed and then re-stocked with fresh food, either hot or cold, with a new label affixed to the container which contains new expiration indicia. It is desirable that the label as adhered to the container be readily removable without significant traces portions of the removed label in order that the container can be quickly relabeled and restocked with food. It is also desirable that a layer of the label, following removal from the container remain intact and not be dissolved or dispersed by water.  
         [0003]     Other embodiments include a variety of structures which can be rolled up to form a roll of labels.  
         [0004]     Under one embodiment, the label of the present invention has five layers as manufactured including a release liner which is removed prior to affixing to the container. For purposes of clarity, the label as manufactured will be referred to as the “as-manufactured” label and the label as affixed to a container will be referred to as the “as-affixed” label. Thus, the as-affixed label of such embodiment has four layers, namely, a water dispersible adhesive layer which is adhered to the container immediately following removal of the release liner, a carrier sheet layer, a layer of conventional pressure sensitive adhesive and a top or outwardly facing indicia layer which may have printed indicia on its outwardly facing surface. The release liner of the as-manufactured label is adjacent the layer of water dispersible adhesive.  
         [0005]     A significant feature of the present invention resides in its functionality in which an outwardly facing indicia layer can be removed from the container and retained for record keeping and one or more layers remain with the container and can be washed away. An additional feature of the present invention is that the face stock retains its integrity even during storage in refrigerators or other areas with high condensation or high humidity. 
     
    
     IN THE DRAWINGS  
       [0006]      FIG. 1  is a sectional view showing the structure of one embodiment of an as-manufactured label.  
         [0007]      FIG. 2  is a schematic sectional view showing removal of the release liner preparatory to affixing the label to a container.  
         [0008]      FIG. 3  is a sectional view of a food container wall with the as-affixed label applied thereto.  
         [0009]      FIG. 4  is a view similar to  FIG. 3  but showing the step of removing the outer indicia layer and the adhesive layer adhered thereto from the carrier sheet and leaving the water dispersible adhesive layer adhering such carrier sheet to the container.  
         [0010]      FIG. 5  is a schematic view showing directing water at the side wall of the container to readily remove the carrier sheet and water dispersible adhesive layer from the container.  
         [0011]      FIG. 6  is a sectional view of another embodiment of an as-manufactured label.  
         [0012]      FIG. 6A  is a schematic sectional view of the embodiment of  FIG. 6  showing removal of a backing layer and its release coating preparatory to affixing the label to a substrate.  
         [0013]      FIG. 7  is a sectional view of an embodiment showing the label structure being formed into a roll of labels.  
         [0014]      FIG. 7A  shows a label unwound from the roll of  FIG. 7  being affixed to a substrate.  
         [0015]      FIG. 8  is a sectional view of an additional embodiment of label structure being formed into a roll of labels.  
         [0016]      FIG. 8A  shows a label unwound from the label structure of  FIG. 8  being applied to a substrate.  
         [0017]      FIG. 8B  shows a label having the structure of  FIG. 8  following affixing to the substrate shown in  FIG. 8A  having a secondary substrate affixed thereto.  
         [0018]      FIG. 9  is a sectional view showing a modified embodiment of an as-manufactured label.  
         [0019]      FIG. 9A  is a schematic sectional view showing the removal of a first carrier sheet and release coating from the as-manufactured label of  FIG. 9  and application of the remaining structure to a substrate.  
         [0020]      FIG. 9B  is a schematic sectional view showing the remaining structure applied to the substrate as shown in  FIG. 9A  and subsequent removal of a second carrier sheet followed by application of a secondary substrate to a water dispersible adhesive layer.  
         [0021]      FIG. 10  is a sectional view of yet another embodiment of label structure being formed into a roll of as-manufactured labels.  
         [0022]      FIG. 10A  is a schematic sectional view showing application of the as-manufactured label structure of  FIG. 10  to a substrate.  
         [0023]      FIG. 10B  is a schematic sectional view of the as-manufactured label structure of  FIG. 10  engaged to the substrate of  FIG. 10A  and subsequently having affixed thereto a secondary substrate following removal of a protective backing.  
         [0024]      FIG. 11  is a sectional view of a further embodiment of as-manufactured label structure.  
         [0025]      FIG. 11A  is a schematic sectional view showing removal of the protective backing sheet and release coating and application of the remaining structure to a substrate.  
         [0026]      FIG. 11B  is a schematic sectional view showing the remaining structure affixed to the substrate as shown in  FIG. 11A  and subsequent removal of a second protective backing sheet followed by application of a secondary substrate. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]     Referring to  FIG. 1 , there is shown one embodiment of the label of the present invention in the as-manufactured state prior to affixing to a container. The as-manufactured label L includes a release liner  1 , a water dispersible adhesive layer  2 , a carrier sheet  3 , a conventional pressure sensitive adhesive layer  4  and a top (as viewed in  FIG. 1 ) layer  5  intended as the outer or viewing layer and, if desired, having printed information thereon.  
         [0028]     The first layer is a release liner  1  which may be a paper or plastic film coated with silicone, wax or other release agent. If the release liner  1  is formed of plastic film, the plastic used may be any of a wide variety including high or low density polyethylene, polyvinyl chloride, polyethylene-terephthalate among others. The second layer is a water dispersible pressure sensitive adhesive layer  2  of a type which will readily release the release liner  1  when the release liner is peeled away therefrom. An important feature of the present invention resides in the adhesive layer  2  being a water dispersible pressure sensitive adhesive in order that the label may be readily removed with water from a food or other container to which it is attached following expiration of the safe life of food or other contents of the container. The water dispersible adhesive, when dispersed in water, is reduced to particles so small that they cannot be seen by the human eye without magnification. Preferably, such dispersed particles have a maximum size of less than one millimeter (1 mm). One suitable type of water dispersible adhesive is one manufactured by Fasson Corporation as its adhesive S-2600.  
         [0029]     Although some adhesives, such as the adhesive disclosed in U.S. Pat. No. 5,624,751, have the property of being deactivated in water to assist in removal from a container, this type of adhesive has a polymer which has an affinity for itself and forms a slurry which requires filtering-off in the recycling process. The water dispersible pressure sensitive adhesive used in the present invention as the water dispersible adhesive layer  2  utilizes ingredients which do not have affinity for themselves and, therefore, do not form undesirable slurries or other adhesive agglomerations. It is possible that adhesives which form slurries when deactivated in water could interfere with the recycling process.  
         [0030]     The third layer carrier sheet  3  is a paper or polymeric film layer such as polyvinyl alcohol (PVOA), high or low density polyethylene, polyvinyl chloride, polyethyleneterephthalate or the like and which has a release coating on the surface facing away from the water dispersible adhesive layer  2 . Preferably the third layer carrier sheet  3  is water permeable to permit ready access of water to the water dispersible adhesive layer  2  when it is desired to remove such layers from the container to which it is attached.  
         [0031]     The fourth layer is a standard pressure sensitive adhesive layer  4  such as one manufactured by Fasson as its adhesive No. AT-20 or No. S-2500 or manufactured by Green Bay Packaging as its adhesive No. 720.  
         [0032]     The fifth layer is a paper or polymeric or other plastic film layer  5  which can be printed upon.  
         [0033]     The use of the label of the present invention in a food rotation labeling application may be seen by considering the steps outlined in  FIGS. 2-5 . In  FIG. 2 , the as-manufactured label L is shown being readied for application to a food or other container C by removing the release liner  1  and thereby leaving an as-affixed label L′ with its water dispersible pressure sensitive adhesive layer  2  exposed for affixing to a wall of a food container C as shown in  FIG. 3 .  
         [0034]     At any time thereafter but specifically after the expiration time for the food or other contents of the container C, the paper or film layer  5  and its adjacent pressure sensitive adhesive layer  4  may be removed and if desired, placed in a log book or other record keeping instrumentation or documentation of the label change and disposal of the container contents. Such record keeping is recommended by various agencies such as Hazard Analysis and Critical Control Point (HACCP) or International Standards Organization (ISO), for example.  
         [0035]     As may be seen in  FIG. 4 , removal of the outer layers, namely, the paper or film layer  5  with printed information and the pressure sensitive adhesive layer  4  leaves the water permeable release layer  3  and the water dispersible adhesive layer  2  adhered to the container C. These layers can then be easily removed from the container C using a water wash or spray W and leaving no adhesive residue on the container.  
         [0036]     As shown in the drawings, the edges of the pressure sensitive adhesive layer  4  and the paper or plastic film layer  5  are recessed from the edges of the carrier sheet  3 . This assists in the peelability of those layers from the carrier sheet  3 . However, it should be understood that the edges of all the layers could be aligned.  
         [0037]     Referring to  FIGS. 6 and 6 A, there is shown another embodiment of label which is shown in the as-manufactured state  10  in  FIG. 6 . The as-manufactured label  10  includes a face layer  11 , a water dispersible adhesive layer  12 , a release coating  14  and a backing layer  15  which is intended to be removed, along with the release coating  14 , from the water dispersible adhesive layer  12  prior to affixing to a substrate S as shown in  FIG. 6A . The face layer  11  is formed of a material which is non-soluble and non-dispersible in water such as a wide variety of paper, plastic films or non-woven fabric. The water dispersible adhesive layer  12  is one which readily disperses in water of any temperature to form particles which cannot be seen by the human eye, for example, the previously referenced adhesive sold by Fasson Corporation as its Adhesive S-2600.  
         [0038]     The backing layer  15  has a release coating  14  such as silicone or wax is engaged to the layer of water soluble adhesive  12  with the release coating  14  contacting such adhesive  12 . The backing layer  15  may be one of a wide variety of well known releasable backing materials common with pressure sensitive labels. As can be seen in  FIG. 6A , the backing layer  15  along with the release coating  14  is removed from the layer of adhesive  12  immediately prior to affixing the face layer  1 ′ and water dispersible adhesive layer  12  to the substrate S with the face layer  11  facing outwardly and the adhesive layer  12  in direct contact with the substrate S. Heretofore water dissolvable and water dispersible labels not requiring a soaking period have been produced with both water soluble or dispersible adhesive and water soluble or dispersible face materials such as the dissolving product sold by Fasson Roll North America, a division of Avery Dennison as Fasson&#39;s Specification No. 16174. The prior art labels sold by the assignee of the present invention using such water soluble face materials also utilized a water soluble adhesive such as Fasson&#39;s S-100-R adhesive which required the water to be at a relatively high temperature (140° F.) and required approximately two minutes dwell time at that temperature to be removed from the surface to which it was attached.  
         [0039]     In contrast, the label of the embodiment of  FIGS. 6 and 6 A of the present invention comprise the face layer  11  which is not soluble or dispersible in water and the adhesive layer  12  which is dispersible in water.  
         [0040]     This label may be removed from a container surface or other substrate S to which it is attached in a significantly shorter time period, for example 30 seconds or possibly less and in any temperature water, thereby avoiding the necessity of utilizing heated water. Furthermore, the label of the present invention has the advantage of allowing the label face layer  11  to remain relatively intact following its removal from the substrate S. The face layer  11  may then either be readily disposed of or, if used on food containers or other applications requiring information retrieval, it may be readily marked upon and saved. This particularly useful in food rotation labeling or inventory tracking.  
         [0041]     Referring to FIGS.  7 and  7 A, there is shown another embodiment which may be characterized as a roll structure  20  since it may be rolled upon itself to form a roll  20 A such as a roll of tape. The roll structure  20  comprises a carrier or face layer  26  such as paper, plastic film or non-woven fabric which is not soluble or dispersible in water and a water dispersible adhesive layer  27  of the type utilized in the previous embodiments, for example, Fasson Corporation&#39;s adhesive S-2600. As can be seen in  FIG. 7 , the roll structure  20  may be rolled upon itself to form a roll  20 A. When it is desired to be dispensed and adhered to a substrate S, it may be simply unwound and the adhesive layer  27  affixed to the substrate S with the carrier or face layer  26  facing outwardly therefrom. This is an advantage over presently available water soluble tapes in that the utilization of a water insoluble/non-dispersible material for the carrier or face layer  26  is lower cost than is required for water soluble tapes in which the entire tape structure is water soluble. This embodiment also has the advantage of being removable in a short period of time, about 30 seconds or less, by exposing to water of any temperature above freezing.  
         [0042]     Referring to  FIGS. 8, 8A  and  8 B, there is shown yet another embodiment of roll structure  30  which may be rolled upon itself to form a roll  30 A, which roll  30 A may be subsequently unrolled and affixed to a substrate S as shown in  FIG. 8A . The roll structure  30  includes a water dispersible adhesive layer  31  of the type previously described, a carrier sheet  32  such as paper, plastic or non-woven fabric which is not soluable or dispersible in water, a first release coating  33  between the adhesive layer  31  and the carrier sheet  32  and a second release coating  34  on the opposite side of the carrier sheet  32  from the first release coating  33 .  
         [0043]     The water dispersible adhesive is one such as the previously described one sold by Fasson as its S-2600, for example. As can be seen in  FIG. 8 , when the roll structure  30  is rolled upon itself to form a roll  30 A, the second release coating  34  will engage and become adhered to the side of the water dispersible adhesive layer  31  which is opposite the first release coating  33 , the lower side of the adhesive layer  31  as viewed in  FIG. 8 . As will be appreciated, it is desirable that the roll  30 A may be unwound so that the second release coating  34  is separated from the adhesive layer  31  without causing the adhesive layer  31  to pull away from the carrier layer  32 . This is accomplished by having a first release coating  33  be one which has stronger release characteristics than that used for the second release coating  34 . The use of release material for the first release coating  33  which has bonding characteristics causing a stronger bond between the adhesive layer  31  and the side  32 B of carrier layer  32  than the bond between the second release coating  34  and the outer surface  32 A of the carrier layer  32  results in retention of the opposite side  32 B of the carrier layer  32  to the adhesive  31  upon unrolling the roll  30 A.  
         [0044]     When thus unrolled, the carrier layer  32  and water dispersible adhesive layer  31  may be engaged to a substrate S as shown in  FIG. 8A . Thereafter, if desired, the carrier layer  32  may be removed or peeled away from the adhesive layer  31  and a secondary substrate S- 1  affixed to the opposing surface of the adhesive of the adhesive layer  31 . The first release coating  33 , although having stronger release characteristics than the second release coating  34 , will permit ready release of the carrier layer  32  from the adhesive layer  31 . One example of a release material for use in the stronger first release coating  33  is one sold by Loparex Inc., subsidiary of UPM-KYMMENE Appeldoorn, Netherlands as its Item No. 6020. An example of a release material utilized for the weaker second release coating  34  is one sold by Loparex Inc. as its Item No. 6000. A typical use for this embodiment would be where the substrate S is a container containing food or other products and the secondary substrate S- 1  is a promotional or informational tag.  
         [0045]     Referring to the embodiment of  FIGS. 9, 9A  and  9 B, there is shown a further embodiment of as-manufactured label structure  40 . The as-manufactured label structure  40  includes a first carrier sheet  41  which is not soluble or dispersible in water, a first release coating  42 , a water dispersible adhesive  43 , a second release coating  44  and a second carrier sheet  45  which is not soluble or dispersible in water. The carrier sheets  41  and  45  can be constructed a wide variety of materials including paper which is not soluble or dispersible in water, a wide variety of plastics or non-woven fabric. The release coatings can be silicone or wax based, with any one of many conventional types of release coatings being satisfactory. The release coating  42  could be formed of the same material as the release coating  44  or it could be formed from different types of coating having different release characteristics such as described in the embodiment of  FIGS. 8, 8A  and  8 B. For example, the release coating  42  could have a stronger release characteristics in releasing the first carrier sheet  41  from the adhesive layer  43  than the release characteristics of the release coating  44  in releasing the second carrier sheet  45  from the water dispersible adhesive layer  43 .  
         [0046]     As shown in  FIG. 9A , in use, the second carrier sheet  45  is peeled away from the water dispersible adhesive layer  43  carrying with it the release coating  44 . The remaining portion of the as-manufactured label  40  may then have the adhesive layer  43  adhered to a first substrate  46 . Thereafter, the carrier sheet  41  along with the release coating  42  may be peeled away from the adhesive layer  43  and a second substrate  47  applied to the surface of the adhesive layer  43  opposite from the side to which the first substrate  46  was attached. This embodiment permits the adhesive layer  43  to be affixed to a first substrate  46  which could be one of a wide variety of surfaces such as the outer surface of a container, for example, and the opposing side of the adhesive layer  43  to have affixed thereto a secondary substrate  47  which could be an informational tag, for example.  
         [0047]     Referring to  FIGS. 10, 10A  and  10 B, there is shown a further embodiment of as-manufactured structure  50  which is suitable for use in forming a roll  50 A. Under this embodiment, the as-manufactured structure  50  includes a first release coating  51 , a protective backing  52 , a second release coating  53 , a first water dispersible adhesive layer  54 , a carrier sheet  55  which is not soluble or dispersible in water, and a second water dispersible adhesive layer  56 . The water dispersible adhesive for both adhesive layers  54  and  56  are of the type previously described which is dispersible in any temperature of water.  
         [0048]     As shown at the right of  FIG. 10 , the as-manufactured structure  50  is wound upon itself to form a roll  50 A with the second adhesive layer  56  forming the inner most layer and the first release coating  51  in contact therewith. Although the first release coating  51  could have properties permitting it and the first protective backing  52  to be removed from the second adhesive layer  56  upon unwinding with less pull force than would be required to remove the second release coating  53  and protective backing  52  from the first adhesive layer  54 , the construction of the as-manufactured structure  50  is such that the first release coating  51  can be identical to the second release coating  53 .  
         [0049]     As shown in  FIG. 1A , upon unwinding of the roll  50 A, a first substrate  57  may be directly adhered to the second adhesive layer  56 . Thereafter, as shown in  FIG. 10B , the protective backing  52  and second release coating  53  may be peeled away from the first layer of water dispersible adhesive  54  and a secondary substrate  58  secured to the side of the adhesive layer  54  opposite from the carrier  55 . Preferably -the carrier  55  is not soluable or dispersible in water. As in the previous embodiment of  FIG. 8B , the first substrate  57  could be the surface of a container, for example, and the secondary substrate  58  could be an informational or promotional tag. Under this embodiment, upon use of the goods on the container represented by the substrate  57  or expiration of the food contained in such container, the container with its substrate  57  and the remaining structure shown in  FIG. 10B  including the secondary substrate  58  may be immersed or otherwise wetted with water to permit removal of the secondary substrate  58 , first water dispersible adhesive  54 , carrier  55  and secondary water dispersible adhesive  56  from the substrate  57 . The immersion or other wetting with water also permits removal of the secondary substrate  58  from the carrier  55  thereby leaving the carrier  55  which may be marked upon for record keeping purposes.  
         [0050]     Referring to  FIGS. 11, 11A  and  11 B, there is shown an additional embodiment of as-manufactured structure  60 . The structure  60  includes a first protective backing sheet  61  which is not soluable or dispersible in water, a first release coating  62 , a first water dispersible adhesive  63 , a carrier sheet  64  which is not soluable or dispersible in water, a second water dispersible adhesive  65 , a second release coating  66  and a second protective backing  67  which is not soluble or dispersible in water. The protective backing sheets  61  and  67  may be formed of a wide variety of materials including paper, plastic or metal foil, or non-woven fabric. The release coatings  62  and  66  may be identical or may have differing release characteristics. The insoluble carrier sheet  64  may be formed of paper which is nonsoluable/nondispersible in water or plastic film or non-woven fabric.  
         [0051]     As shown in  FIG. 11A , in use the second protective backing  67  may be peeled away from the second layer of water dispersible adhesive  65  carrying with it the second release coating  66 . Thereafter a first substrate  68  may be affixed to the second adhesive layer  65 . The first protective backing  61  may then be removed from the first layer of water dispersible adhesive  63 , carrying with it the first release coating  62 . A secondary substrate  69  may then be affixed to the layer of water dispersible adhesive  63  thereby leaving a final structure of first substrate  68  and secondary substrate  69  having sandwiched therebetween the insoluble carrier sheet  64  and the first and second layers of adhesive  63  and  65  respectively.  
         [0052]     The as-manufactured structure  60  as shown in  FIG. 11  is in effect a double sided tape with separate protective backings  61  and  67  on each layer of adhesive  63  and  65 , respectively. This embodiment provides additional capabilities over the structure shown in  FIGS. 10, 10A  and  10 B which must be immediately used upon rolling. In contract, the structure  60  of  FIG. 11 , although more expensive than the structure  50  of  FIG. 10  and roll  50 A of  FIG. 10A , can be stored for extended periods of time.  
         [0053]     Many modifications will become readily apparent to those skilled in the art. Accordingly, the scope of the present invention should be determined solely by the scope of the appended claims.