Information
                
                    - 
                         Patent Grant Patent Grant
- 
                         6410135 6410135
 
         
    
    
        
            
                - 
                    Patent Number6,410,135
- 
                    Date FiledFriday, January 21, 200025 years ago 
- 
                    Date IssuedTuesday, June 25, 200223 years ago 
 
     
    
        
            
                - 
                            Inventors
- 
                            Original Assignees
- 
                                Examiners
                    - Zirker; Daniel
- Chang; Victor
 Agents
 
     
    
        
            
                - 
                            CPC
- 
                            US ClassificationsField of Search
                - US
- 428 343
- 428 3173
- 428 354
- 428 213
 
- 
                            International Classifications
- 
                            
                
 
     
        
     
    
        
        
    
        
            
        Abstract
A stretch releasing adhesive tape article including an elongated length of stretch releasing adhesive tape with side surfaces including at least one potential contact surface area. At least a portion of the potential contact surface area includes an adhesive surface. The potential contact surface area includes a first interface surface area in the uncompressed state and a second interface surface area greater than the first interface surface area in the compressed state. The stretch releasing adhesive tape in the uncompressed state can operate as a pull tab. The potential contact surface area in the uncompressed state can include a plurality of raised portions, a non-planar structure, or a discontinuous surface.             
         
        
            
                    Description
  
    
      
        FIELD OF THE INVENTION
      
    
    
      
        The present invention relates generally to an elongated stretch releasing adhesive tape article with a geometry that provides differential adhesive properties, and in particular, to a geometry that provides regions of reduced adhesion to form pull-tabs.
      
    
    
      
        BACKGROUND OF THE INVENTION
      
    
    
      
        Stretch releasing adhesive tapes represent an emerging class of high performance pressure-sensitive adhesives combining strong holding power with clean removal and no surface damage. Such stretch releasing adhesive tapes are useful in a wide variety of assembling, joining, attaching, and mounting applications.
      
    
    
      
        Adhesive tape strips that can be cleanly removed from a surface by stretching the tape strip are known in the patented prior art. The Korpman U.S. Pat. No. 4,024,312, for example, discloses a highly conformable adhesive tape including a highly extensible and elastic backing film laminated with an adhesive layer. The backing film possesses a lengthwise elongation at break of at least about 200%. The tape is easily stretchable and may be removed from a surface by stretching the tape lengthwise in a direction substantially parallel to the surface. German Patent No. 33 31 016 discloses a high elasticity, low plasticity adhesive film based on a thermoplastic rubber and tackifying resins, wherein the adhesive bond can be broken by stretching the adhesive film in the direction of the plane of the adhesive bond.
      
    
    
      
        The Kreckel et al. U.S. Pat. No. 5,516,581, assigned to the same assignee as the present invention, discloses a removable adhesive tape having a highly extensible and substantially inelastic backing coated with a layer of pressure sensitive adhesive. The adhesive tape can be removed from a substrate without damaging the substrate by stretching the tape in a direction substantially parallel to the surface of the substrate. The tape backing has a lengthwise elongation at break of from about 150% to about 1200%, a Young's modulus of at least about 2,500 psi to about 72,500 psi, and an elastic recovery of less than about 50% after being stretched and removed. PCT International Publication No. WO 95/06691 discloses a removable foam adhesive tape comprising a backing including a layer of polymeric foam, and a layer of pressure-sensitive adhesive coated on at least one surface of the backing. The foam layer of the backing has a thickness of about 30 to about 1000 mils, and the backing has a lengthwise elongation at break of from about 50% to about 1200%, and a Young's modulus of less than about 2,400 psi.
      
    
    
      
        Commercial stretch releasing adhesive tapes include the product sold under the trade designation COMMAND by Minnesota Mining and Manufacturing Company, St. Paul, Minn., and the product sold under the trade designation POWER-STRIPS by Beiersdorf A G, Hamburg, Germany. These products are currently manufactured as discrete strips with one end of the strip including a non-adhesive pull tab to facilitate stretching of the strip during removal. The adhesive surfaces of the strip are additionally protected with a release liner.
      
    
    
      
        Desirable for certain applications is an elongated stretch releasing adhesive tape strip of indefinite length which can be formed into a roll or stack from which segments of selected length can be cut depending on the end use application. The difficulty with providing a long length of stretch releasing tape which can be cut to a selected length is the ability to provide a pull tab at a specific location on the cut strip to serve as a grasping area for stretching the strip from a surface at the time of removal.
      
    
    
      
        PCT International Publication No. WO 98/06652 discloses a length cutting fixture that can be used to form a non-adhesive pull tab or “gripper” at the end of a long length of a conventional single-sided adhesive tape. The length cutting fixture also serves to cut the long length of tape, now including the gripper, to any selected length. The gripper is formed by folding the end of the tape back onto itself. Such a length cutting fixture, however, cannot be used to form a non-adhesive pull tab on a double-sided adhesive tape.
      
    
    
      
        It is therefore desirable to provide a stretch releasing adhesive tape article in a long length or a roll that can be cut into discrete strips having any selected length, wherein each strip can be provided with a pull tab or stretch removal tab that can be grasped and pulled by a user to remove the adhesive tape from a substrate.
      
    
    
      
        BRIEF SUMMARY OF THE INVENTION
      
    
    
      
        The present invention relates to various embodiments of a stretch releasing adhesive tape with a geometry that provides differential adhesive properties in a compressed state and an uncompressed state. Adhesion and tack can thus be controlled by varying the amount of compression. Additionally, the present stretch releasing adhesive tape can be easily repositioned prior to compression. A portion of the present stretch releasing adhesive tape can be left in the uncompressed state, thereby providing one or more pull tabs. The stretch releasing adhesive tape of the present invention can be provided in strips of varying lengths, in roll form, or in a stack.
      
    
    
      
        In one embodiment, the stretch releasing adhesive tape article includes an elongated length of stretch releasing adhesive tape with side surfaces comprising at least one potential contact surface area. At least a portion of the potential contact surface area comprises an adhesive surface having raised portions. The potential contact surface area comprises a first interface surface area in the uncompressed state and a second interface surface area greater than the first interface surface area in the compressed state. The stretch releasing adhesive tape in the uncompressed state can operate as a pull tab.
      
    
    
      
        In another embodiment, the stretch releasing adhesive tape article comprises an elongated length of stretch releasing adhesive tape with adhesive on all side surfaces. The side surfaces have at least one potential contact surface area. The potential contact surface area has a first interface surface area in an uncompressed state and a second interface surface area greater than the first interface surface area in a compressed state.
      
    
    
      
        In one embodiment, the stretch releasing adhesive tape comprises a multi-layered structure. The stretch releasing adhesive tape can have one or more elastic or inelastic structural members. The structural member can be foam, film, a monofilament or a variety of other materials. A film can optionally be interposed between the adhesive and the structural member or located at the interior of the structural member. The stretch releasing adhesive tape can be one of a pressure sensitive adhesive tape with an elastic structural member, a pressure sensitive adhesive tape with a highly extensible and substantially inelastic structural member, or a solid pressure sensitive adhesive.
      
    
    
      
        In the various embodiments, the potential contact surface area in the uncompressed state can be a plurality of raised portions, a non-planar structure, a discontinuous surface, or combinations thereof The stretch releasing adhesive tape in the uncompressed state comprises a cross-section selected from circular, star-shaped, oval, multifaceted or any other geometric shape that provides less surface area in the uncompressed state than in the compressed state. In another embodiment, the potential contact surface area comprises a rectangular cross-section of stretch releasing adhesive tape twisted to form helical ridges. The potential contact surface area can have adhesive regions and non-adhesive regions.
      
    
    
      
        The elongated length of stretch releasing adhesive tape can be segments or a roll. A release liner may optionally be used. Frangible connections can be formed intermittently along the stretch releasing adhesive tape.
      
    
    
      
        The present invention is also direct to a method of using a stretch releasing adhesive tape article with differential adhesive properties, including the steps of positioning a potential contact surface area of an elongated length of stretch releasing adhesive tape on a substrate to form a first interface surface area; compressing a portion of the stretch releasing adhesive tape to form a second interface surface area, the second interface surface area being greater than the first interface surface area; and retaining an uncompressed portion of the stretch releasing adhesive tape as a pull tab.
      
    
    
      
        In another method the steps include providing an elongated length of stretch releasing adhesive tape with a generally rectangular cross section; twisting at least a portion of the stretch releasing adhesive tape to form a twisted portion with a plurality of helical ridges; positioning the stretch releasing adhesive tape on a substrate, the twisted portion defining a first interface surface area; compressing an untwisted portion of the stretch releasing adhesive tape against the substrate to form a second interface surface area greater than the first interface surface area; and retaining the twisted portion in an uncompressed state to form a pull tab.
      
    
  
  
    
      
        BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
      
    
    
      
        The present invention will be further described with reference to the accompanying drawings, in which:
      
    
    
      
        
          FIG. 1
        
         is a front view of an article attached to a substrate using a stretch releasing adhesive.
      
    
    
      
        
          FIG. 2
        
         is perspective view of a stretch releasing adhesive tape with a rectangular shape.
      
    
    
      
        
          FIG. 3A
        
         is a perspective view of a stretch releasing adhesive tape in an uncompressed state in accordance with the present invention.
      
    
    
      
        
          FIG. 3B
        
         is a perspective view of the stretch releasing adhesive tape of 
        
          FIG. 3A
        
         in a compressed state.
      
    
    
      
        
          FIG. 4A
        
         is a perspective view of an alternate stretch releasing adhesive tape in an uncompressed state in accordance with the present invention.
      
    
    
      
        
          FIG. 4B
        
         is a perspective view of the stretch releasing adhesive tape of 
        
          FIG. 4A
        
         in the compressed state.
      
    
    
      
        
          FIG. 5A
        
         is perspective view of a stretch releasing adhesive tape in an uncompressed state in accordance with the present invention.
      
    
    
      
        
          FIG. 5B
        
         is perspective view of the stretch releasing adhesive tape of 
        
          FIG. 5A
        
         in the compressed state.
      
    
    
      
        
          FIG. 6A
        
         is perspective view of a stretch releasing adhesive tape in an uncompressed state in accordance with the present invention.
      
    
    
      
        
          FIG. 6B
        
         is a perspective view of the stretch releasing adhesive tape of 
        
          FIG. 6A
        
         in the compressed state.
      
    
    
      
        
          FIG. 7
        
         is a perspective view of a stretch releasing adhesive tape with helical ridges in accordance with the present invention.
      
    
    
      
        
          FIG. 8
        
         is a perspective view of a stretch releasing adhesive tape with a rectangular portion and a portion with helical ridges in accordance with the present invention.
      
    
    
      
        
          FIG. 9A
        
         is perspective view of a stretch releasing adhesive tape with discontinuous adhesive regions in an uncompressed state in accordance with the present invention.
      
    
    
      
        
          FIG. 9B
        
         is a perspective view of the stretch releasing adhesive tape of 
        
          FIG. 9A
        
         in the compressed state.
      
    
    
      
        
          FIG. 10
        
         is a front view of an article attached to a substrate using a stretch releasing adhesive tape in accordance with the present invention.
      
    
    
      
        
          FIG. 11
        
         is a front view of an article attached to a substrate using an alternate stretch releasing adhesive in accordance with the present invention.
      
    
    
      
        
          FIG. 12
        
         is a perspective view of a stretch releasing adhesive tape in roll form in accordance with the present invention.
      
    
    
      
        
          FIG. 13
        
         is a perspective view of an alternate roll of stretch releasing adhesive tape in accordance with present invention.
      
    
  
  
    
      
        DETAILED DESCRIPTION OF THE INVENTION
      
    
    
      
        
          FIG. 1
        
         is a front view of an article 
        
          
            20
          
        
         attached to a substrate 
        
          
            22
          
        
         using a stretch releasing adhesive tape 
        
          
            24
          
        
        . A portion 
        
          
            21
          
        
         of the stretch releasing adhesive tape 
        
          
            24
          
        
         is compressed between the article 
        
          
            20
          
        
         and the substrate 
        
          
            22
          
        
         to form an adhesive bond. The stretch releasing adhesive 
        
          
            24
          
        
         includes a pull tab 
        
          
            26
          
        
         that extends beyond the perimeter of the article 
        
          
            20
          
        
        . The pull tab 
        
          
            26
          
        
         typically includes non-adhesive surfaces that prevent bonding with the substrate 
        
          
            22
          
        
         or the article 
        
          
            20
          
        
        .
      
    
    
      
        Removing the stretch releasing adhesive tape 
        
          
            24
          
        
         from the article 
        
          
            20
          
        
         and substrate 
        
          
            22
          
        
         can be carried out by simply stretching the stretch releasing adhesive tape 
        
          
            24
          
        
         in the direction 
        
          
            28
          
        
         and at an angle of less than about 35 degrees with respect to the substrate 
        
          
            22
          
        
        . Removal at the appropriate angle will result in no appreciable adhesive residue on the substrate 
        
          
            22
          
        
         and in preventing damage to the substrate 
        
          
            22
          
        
        .
      
    
    
      
        
          FIG. 2
        
         is a perspective view of a segment of a stretch releasing adhesive tape 
        
          
            30
          
        
         having a generally rectangular cross section. The stretch releasing adhesive tape 
        
          
            30
          
        
         has a length 
        
          
            32
          
        
        , a width 
        
          
            34
          
        
        , and a thickness 
        
          
            36
          
        
        . The stretch releasing adhesive tape 
        
          
            30
          
        
         has a potential contact surface area 
        
          
            38
          
        
         and a first interface surface area 
        
          
            40
          
        
         defined by the length 
        
          
            32
          
        
         times the width 
        
          
            34
          
        
        . As used herein, “potential contact surface area” refers to the surface area on a stretch releasing adhesive tape that can potentially contact a planar substrate, whether or not there is adhesive at the interface with the substrate. For stretch releasing adhesive tapes with a more complex geometry, the potential contact surface area can also be understood as the portion of the side surfaces that are illuminated by a light shined perpendicular through transparent substrate 
        
          
            22
          
        
         onto the stretch releasing adhesive tape. The “first interface surface area” refers to the surface area formed at the actual physical interface between the stretch releasing adhesive tape and the substrate 
        
          
            22
          
        
         in the uncompressed state. Due to the geometry of the stretch releasing adhesive tape 
        
          
            30
          
        
        , the potential contact surface area 
        
          
            38
          
        
         on the stretch releasing adhesive tape 
        
          
            30
          
        
         and the first interface surface area 
        
          
            40
          
        
         with the substrate 
        
          
            22
          
        
         are substantially the same.
      
    
    
      
        In the embodiment illustrated in 
        
          FIG. 2
        
        , portion 
        
          
            42
          
        
         of the stretch releasing adhesive 
        
          
            30
          
        
         is compressed against the substrate 
        
          
            22
          
        
        , while portion 
        
          
            44
          
        
         remains uncompressed. No pull tab is provided. The portion 
        
          
            42
          
        
         forms a strong adhesive bond with the substrate 
        
          
            22
          
        
        , while the portion 
        
          
            44
          
        
         initially forms less of an adhesive bond. Over time, however, the uncompressed portion 
        
          
            44
          
        
         will wet-out against the substrate 
        
          
            22
          
        
         and build adhesion. Consequently, the interface surface area 
        
          
            40
          
        
         is effectively the same whether all or a portion of the stretch releasing adhesive tape 
        
          
            30
          
        
         is compressed against the substrate 
        
          
            22
          
        
        .
      
    
    
      
        
          FIGS. 3A and 3B
        
         illustrate a stretch releasing adhesive tape 
        
          
            50
          
        
         with differential adhesive properties in accordance with the present invention. Side surfaces 
        
          
            54
          
        
         of the stretch releasing adhesive tape 
        
          
            50
          
        
         include a pressure sensitive adhesive. The pressure sensitive adhesive can cover some or all of the side surfaces 
        
          
            54
          
        
        . For example, the pressure sensitive adhesive can be a continuous or discontinuous region on the side surfaces 
        
          
            54
          
        
        . In the illustrated embodiment, the stretch releasing adhesive tape 
        
          
            50
          
        
         is a multi-layered structure, including a structural member 
        
          
            51
          
        
        , such as an elastic or inelastic foam, and a film 
        
          
            53
          
        
         interposed between the structural member 
        
          
            51
          
        
         and the adhesive layer 
        
          
            55
          
        
         that defines the side surfaces 
        
          
            54
          
        
        . The structural member 
        
          
            51
          
        
         can be concentric or non-concentric with the adhesive layer 
        
          
            55
          
        
        , hollow or solid, or symmetrical or asymmetrical with the adhesive layer 
        
          
            55
          
        
        . Any conventionally known stretch releasing tape, however, can be used in the various embodiments of the present invention, including a pressure sensitive adhesive tape with an elastic core, a pressure sensitive adhesive tape with a highly extensible and substantially inelastic core, or a solid pressure sensitive adhesive. These various structures can be used with any embodiment of the present invention.
      
    
    
      
        Specific tapes suitable for use in the various embodiments of the present invention include the pressure sensitive adhesive tapes with elastic backings described in U.S. Pat. No. 4,024,312 (Korpman), the pressure sensitive adhesive tapes with highly extensible and substantially inelastic backings described in U.S. Pat. No. 5,516,581 (Kreckel et al.) and PCT International Publication No. WO 95/06691 (Bries et al); and the solid pressure sensitive adhesive described in German Patent No. 33 31 016. In addition, the stretch releasing adhesive tape of the present invention can include a splittable layer such as the layers described in PCT International Publication No. WO 98/21285, or a re-fastenable layer such as the layers described in PCT International Publication No. WO 99/31193.
      
    
    
      
        
          FIG. 3A
        
         illustrates the stretch releasing adhesive tape 
        
          
            50
          
        
         adhered to a substrate 
        
          
            22
          
        
         in an uncompressed state 
        
          
            52
          
        
        . The adhesive side surfaces 
        
          
            54
          
        
         have a potential contact surface area 
        
          
            56
          
        
         defined by arc length 
        
          
            60
          
        
         times length 
        
          
            62
          
        
        . The first interface surface area 
        
          
            58
          
        
        , however, is defined by arc length 
        
          
            64
          
        
         times the length 
        
          
            62
          
        
        . The circular cross section of the stretch releasing adhesive 
        
          
            50
          
        
         causes the first interface surface area 
        
          
            58
          
        
         with the substrate 
        
          
            22
          
        
         to be significantly smaller than the potential contact surface area 
        
          
            56
          
        
        .
      
    
    
      
        
          FIG. 3B
        
         illustrates the stretch releasing adhesive tape 
        
          
            50
          
        
         of 
        
          FIG. 3A
        
         in the compressed state 
        
          
            70
          
        
        . In the compressed state 
        
          
            70
          
        
        , the potential contact surface area 
        
          
            56
          
        
         defines a second interface surface area 
        
          
            72
          
        
         greater than the first interface surface area 
        
          
            58
          
        
        . The “second interface surface area” refers to the surface area formed at the actual physical interface between the stretch releasing adhesive tape and the substrate 
        
          
            22
          
        
         in the compressed state. In the embodiment of 
        
          FIG. 3B
        
        , the second interface surface area 
        
          
            72
          
        
         is defined by the width 
        
          
            71
          
        
         times the length 
        
          
            62
          
        
        . As illustrated in 
        
          FIG. 3B
        
        , the second interface surface area 
        
          
            72
          
        
         is less than the potential contact surface area 
        
          
            56
          
        
        , although in some embodiments, they can be substantially the same.
      
    
    
      
        Due to the increase in surface area, the stretch releasing adhesive tape 
        
          
            50
          
        
         has greater adhesion with the substrate 
        
          
            22
          
        
         in the compressed state 
        
          
            70
          
        
         than in the uncompressed state 
        
          
            52
          
        
        . By selectively leaving portions of the stretch releasing adhesive tape 
        
          
            50
          
        
         in the uncompressed state, those portions can be later removed from the substrate 
        
          
            22
          
        
         and used as pull tabs (see FIGS. 
        
          
            10
          
        
         and 
        
          
            11
          
        
        ). Additionally, the first interface surface area 
        
          
            58
          
        
         can be made sufficiently small that the pressure sensitive adhesive tape 
        
          
            50
          
        
         can be easily repositioned prior to compression into the compressed state 
        
          
            70
          
        
        .
      
    
    
      
        
          FIG. 4A
        
         illustrates an alternate stretch releasing adhesive tape 
        
          
            80
          
        
         in an uncompressed state 
        
          
            82
          
        
         in accordance with the present invention. The stretch releasing adhesive tape 
        
          
            80
          
        
         includes a series of raised portions 
        
          
            96
          
        
        A, 
        
          
            96
          
        
        B, 
        
          
            96
          
        
        C, 
        
          
            96
          
        
        D. A non-planar adhesive contact surface 
        
          
            86
          
        
         includes raised portions 
        
          
            96
          
        
        C, 
        
          
            96
          
        
        D. Raised portions 
        
          
            96
          
        
        C, 
        
          
            96
          
        
        D define a pair of narrow, discrete first interface surface areas 
        
          
            92
          
        
        , 
        
          
            94
          
        
        , respectively, with the substrate 
        
          
            22
          
        
         in the uncompressed state 
        
          
            82
          
        
        . Rather than the single continuous interface surface area 
        
          
            58
          
        
         of 
        
          FIG. 3A
        
        , the interface surface areas 
        
          
            92
          
        
        , 
        
          
            94
          
        
         are discrete and discontinuous. In the uncompressed state 
        
          
            82
          
        
        , the level of adhesion generated by the first interface surface areas 
        
          
            92
          
        
        , 
        
          
            94
          
        
         is sufficiently low that a user can reposition the stretch releasing adhesive tape 
        
          
            80
          
        
         or detach a portion of the stretch releasing adhesive tape 
        
          
            80
          
        
         from the substrate 
        
          
            22
          
        
         and use the detached portion as a pull tab.
      
    
    
      
        
          FIG. 4B
        
         illustrates the stretch releasing adhesive tape 
        
          
            80
          
        
         of 
        
          FIG. 4A
        
         in a compressed state 
        
          
            84
          
        
        . In the compressed state 
        
          
            84
          
        
        , the first interface surface areas 
        
          
            92
          
        
        , 
        
          
            94
          
        
         are expanded to form the second interface surface area 
        
          
            95
          
        
         that is defined by the width 
        
          
            97
          
        
         times the length 
        
          
            99
          
        
        . In the embodiment of 
        
          FIG. 4B
        
        , the second interface surface area 
        
          
            95
          
        
         is substantially the same as the potential contact surface area 
        
          
            86
          
        
        . Once the stretch releasing adhesive tape 
        
          
            80
          
        
         is compressed against the substrate 
        
          
            22
          
        
        , as illustrated in 
        
          FIG. 4B
        
        , it cannot be easily removed without a pull tab. By selectively leaving portions of the stretch releasing adhesive tape 
        
          
            80
          
        
         in the uncompressed state, the uncompressed portions can be used as pull tabs.
      
    
    
      
        
          FIGS. 5A and 5B
        
         illustrate a cross sectional view of an alternate stretch releasing adhesive tape 
        
          
            100
          
        
         in accordance with the present invention. 
        
          FIG. 5A
        
         illustrates the stretch releasing adhesive tape in the uncompressed state 
        
          
            102
          
        
        . In the uncompressed state 
        
          
            102
          
        
        , the stretch releasing adhesive tape 
        
          
            100
          
        
         includes a series of raised portions 
        
          
            104
          
        
        A, 
        
          
            104
          
        
        B, 
        
          
            104
          
        
        C, 
        
          
            104
          
        
        D, 
        
          
            104
          
        
        E. Potential contact surface area 
        
          
            110
          
        
         is defined by the segments 
        
          
            105
          
        
        , 
        
          
            107
          
        
         times the length 
        
          
            109
          
        
        . In the uncompressed state 
        
          
            102
          
        
        , however, tips of the raised portions 
        
          
            104
          
        
        B, 
        
          
            104
          
        
        C times the length 
        
          
            109
          
        
         define a pair of discontinuous, non-planar first interface surface areas 
        
          
            106
          
        
        , 
        
          
            108
          
        
         with the substrate 
        
          
            22
          
        
        . The sum of the first interface surface areas 
        
          
            106
          
        
        , 
        
          
            108
          
        
         is significantly smaller than the potential contact surface area 
        
          
            110
          
        
        . If a portion of the stretch releasing adhesive tape 
        
          
            100
          
        
         is retained in the uncompressed state 
        
          
            102
          
        
        , that portion can be removed from the substrate 
        
          
            22
          
        
         and used as a pull tab or repositioned.
      
    
    
      
        
          FIG. 5B
        
         illustrates the stretch releasing adhesive tape 
        
          
            100
          
        
         of 
        
          FIG. 5A
        
         in a compressed state 
        
          
            116
          
        
        . Raised portions 
        
          
            104
          
        
        B and 
        
          
            104
          
        
        C have been collapsed against the substrate 
        
          
            22
          
        
         so that the second interface surface area 
        
          
            118
          
        
         is the sum of the segments 
        
          
            105
          
        
        , 
        
          
            107
          
        
         times the length 
        
          
            109
          
        
        , substantially the same as the potential contact surface area 
        
          
            110
          
        
        .
      
    
    
      
        
          FIG. 6A and 6B
        
         illustrate an alternate stretch releasing adhesive tape 
        
          
            130
          
        
         in accordance with the present invention. 
        
          FIG. 6A
        
         illustrates the stretch releasing adhesive tape 
        
          
            130
          
        
         in the uncompressed state 
        
          
            132
          
        
        . The stretch releasing adhesive tape 
        
          
            130
          
        
         includes a series of longitudinal ridges or raised portions 
        
          
            134
          
        
         that define the first interface surface area 
        
          
            136
          
        
        . The raised portions 
        
          
            134
          
        
         can be formed on one or more surfaces of the stretch releasing adhesive tape 
        
          
            130
          
        
        . In the embodiment illustrated in 
        
          FIG. 6A
        
        , the first interface surface area 
        
          
            136
          
        
         is a series of elongated strips that correspond to the tips of the raised portions 
        
          
            134
          
        
        . The potential contact surface area 
        
          
            138
          
        
         is defined by the contour of the raised portions 
        
          
            134
          
        
         times the length 
        
          
            142
          
        
         of the stretch releasing adhesive tape 
        
          
            130
          
        
        . The first interface surface area 
        
          
            136
          
        
        , however, is significantly smaller than the potential contact surface area 
        
          
            138
          
        
         due to the non-planar structure defined by the ridges 
        
          
            134
          
        
        .
      
    
    
      
        
          FIG. 6B
        
         illustrates the stretch releasing adhesive tape 
        
          
            130
          
        
         of 
        
          FIG. 6A
        
         in the compressed state 
        
          
            146
          
        
        . In the embodiment illustrated in 
        
          FIG. 6B
        
        , the second interface surface area 
        
          
            144
          
        
         is greater than the first interface surface area 
        
          
            136
          
        
        , but less than the potential contact surface area 
        
          
            138
          
        
        . This result is due to incomplete compression of the stretch releasing adhesive tape 
        
          
            130
          
        
         at the locations 
        
          
            148
          
        
         against the substrate 
        
          
            22
          
        
        . In an alternate embodiment, the stretch releasing adhesive tape 
        
          
            130
          
        
         is fully compressed so that the second interface surface area 
        
          
            144
          
        
         is substantially the same as the potential contact surface area 
        
          
            138
          
        
        .
      
    
    
      
        
          FIG. 7
        
         illustrates an alternate stretch releasing adhesive tape 
        
          
            150
          
        
         with a generally rectangular cross section 
        
          
            152
          
        
         that has been twisted to form a series of helical ridges or raised portions 
        
          
            154
          
        
        . The helical ridges 
        
          
            154
          
        
         form discrete raised portions that define a first interface surface area 
        
          
            155
          
        
         significantly smaller than the potential contact surface area 
        
          
            158
          
        
         defined by the width 
        
          
            160
          
        
         and length 
        
          
            162
          
        
         of the stretch releasing adhesive tape 
        
          
            150
          
        
         in the un-twisted state.
      
    
    
      
        
          FIG. 8
        
         illustrates an alternate stretch releasing adhesive tape 
        
          
            170
          
        
         having a generally rectangular cross section 
        
          
            172
          
        
        . Portion 
        
          
            171
          
        
         of the stretch releasing adhesive tape 
        
          
            170
          
        
         is compressed against the substrate 
        
          
            22
          
        
         in its rectangular form. Distal end 
        
          
            174
          
        
         is twisted to define a plurality of helical ridges or raised portions 
        
          
            176
          
        
        . The distal end 
        
          
            174
          
        
         is retained in its uncompressed state so that the helical ridges 
        
          
            176
          
        
         define a first interface surface area 
        
          
            175
          
        
         significantly smaller than the potential contact surface area 
        
          
            178
          
        
         for the distal portion 
        
          
            174
          
        
         (as defined by the width 
        
          
            180
          
        
         and length 
        
          
            182
          
        
        ). The ridges 
        
          
            176
          
        
         permit that the distal end 
        
          
            174
          
        
         to be removed from the substrate 
        
          
            22
          
        
         to serve as pull tab for detaching the compressed portion 
        
          
            171
          
        
         from the substrate 
        
          
            22
          
        
        .
      
    
    
      
        
          FIG. 9A
        
         illustrates a hollow stretch releasing adhesive tape 
        
          
            280
          
        
         having a center aperture 
        
          
            282
          
        
         and a series of adhesive regions 
        
          
            283
          
        
        
          
            a, 
          
        
        
          
            283
          
        
        
          
            b, 
          
        
        
          
            283
          
        
        
          
            c, 
          
        
        
          
            283
          
        
        
          
            d 
          
        
        (referred to collectively as 
        
          
            283
          
        
        ) each having a plurality of discrete raised portions or bumps 
        
          
            284
          
        
        
          
            a, 
          
        
        
          
            284
          
        
        
          
            b, 
          
        
        
          
            284
          
        
        
          
            c, 
          
        
        
          
            284
          
        
        
          
            d 
          
        
        (referred to collectively as 
        
          
            284
          
        
        ). The adhesive regions 
        
          
            283
          
        
         can be continuous or discontinuous, regularly shaped or irregularly shaped, longitudinally oriented or spiral strips, or a variety of other configurations. The raised portions or bumps 
        
          
            284
          
        
         can be a variety of shapes, such as cones, pyramids, hemispherical projections, or irregular shape protrusions. A series of non-adhesive regions 
        
          
            285
          
        
        
          
            a, 
          
        
        
          
            285
          
        
        
          
            b, 
          
        
        
          
            285
          
        
        
          
            c, 
          
        
        
          
            285
          
        
        
          
            d 
          
        
        are positioned between the adhesive regions 
        
          
            283
          
        
        . In the uncompressed state 
        
          
            286
          
        
        , only the tips of the raised adhesive portions 
        
          
            284
          
        
        
          
            c 
          
        
        are in contact with the substrate 
        
          
            22
          
        
        , defining a relatively small first interface surface area 
        
          
            288
          
        
        . In the uncompressed state 
        
          
            286
          
        
        , the first interface surface area 
        
          
            288
          
        
         permits the stretch releasing adhesive tape 
        
          
            280
          
        
         to be repositioned or removed from the substrate 
        
          
            22
          
        
         to serve as a pull tab.
      
    
    
      
        Potential contact surface area 
        
          
            290
          
        
         is defined by the arc length 
        
          
            292
          
        
         times the length 
        
          
            294
          
        
        . As is clear from 
        
          FIG. 9A
        
        , the potential contact surface area 
        
          
            290
          
        
         includes adhesive region 
        
          
            283
          
        
        
          
            c, 
          
        
        portions of adhesive regions 
        
          
            283
          
        
        
          
            b, 
          
        
        
          
            283
          
        
        
          
            d 
          
        
        and non-adhesive regions 
        
          
            285
          
        
        
          
            b, 
          
        
        
          
            285
          
        
        
          
            c. 
          
        
      
    
    
      
        
          FIG. 9B
        
         illustrates the stretch releasing adhesive tape 
        
          
            280
          
        
         of 
        
          FIG. 9A
        
         in the compressed state 
        
          
            296
          
        
        . Aperture 
        
          
            282
          
        
         facilitates compression. In the compressed state 
        
          
            296
          
        
        , second interface surface area 
        
          
            298
          
        
         is greater than the first interface surface area 
        
          
            288
          
        
        . The second interface surface area 
        
          
            298
          
        
         is defined by the width 
        
          
            300
          
        
         times the length 
        
          
            294
          
        
        . The second interface surface area 
        
          
            298
          
        
         includes the adhesive region 
        
          
            283
          
        
        
          
            c, 
          
        
        portions of the adhesive regions 
        
          
            283
          
        
        
          
            b, 
          
        
        
          
            283
          
        
        
          
            d 
          
        
        and the non-adhesive regions 
        
          
            285
          
        
        
          
            b, 
          
        
        
          
            285
          
        
        
          
            c. 
          
        
        In the embodiment illustrated in 
        
          FIG. 9B
        
        , the second interface surface area 
        
          
            298
          
        
         is less than the potential contact surface area 
        
          
            290
          
        
        , although in some embodiments, they can be substantially the same.
      
    
    
      
        
          FIG. 10
        
         is a front view of an article 
        
          
            20
          
        
         attached to a substrate 
        
          
            22
          
        
         using a stretch releasing adhesive tape 
        
          
            190
          
        
         in accordance with the present invention. Portion 
        
          
            192
          
        
         of the stretch releasing adhesive tape 
        
          
            190
          
        
         is compressed between the substrate 
        
          
            22
          
        
         and the article 
        
          
            20
          
        
        . Compressed portion 
        
          
            192
          
        
         defines a second interface surface area 
        
          
            196
          
        
         having a length 
        
          
            198
          
        
         and a width 
        
          
            200
          
        
        .
      
    
    
      
        Exposed portion 
        
          
            202
          
        
         of the stretch releasing adhesive tape 
        
          
            190
          
        
         is retained in an uncompressed state 
        
          
            204
          
        
        . The geometry of the exposed portion 
        
          
            202
          
        
         defines a first interface surface area 
        
          
            206
          
        
         with the substrate 
        
          
            22
          
        
         that is less then the potential contact surface area available for engagement with the substrate 
        
          
            22
          
        
        . Consequently, the level of adhesion of the exposed portion 
        
          
            202
          
        
         is low enough to permit it to serve as a pull tab for removing the compressed portion 
        
          
            192
          
        
         from the substrate 
        
          
            22
          
        
        .
      
    
    
      
        
          FIG. 11
        
         is a front view of an alternate stretch releasing adhesive tape 
        
          
            210
          
        
         in accordance with the present invention. Compressed portion 
        
          
            212
          
        
         is located between the article 
        
          
            20
          
        
         and substrate 
        
          
            22
          
        
        . Due to the geometry of the stretch releasing adhesive tape 
        
          
            210
          
        
        , the compressed portion 
        
          
            212
          
        
         can follow a serpentine or other non-linear path, thereby increasing the size of the interface surface area 
        
          
            214
          
        
        , and hence the adhesive bond between the substrate 
        
          
            22
          
        
         and article 
        
          
            20
          
        
        .
      
    
    
      
        The exposed portion 
        
          
            216
          
        
         is retained in an uncompressed state 
        
          
            218
          
        
        . Due to the geometry of the stretch releasing adhesive tape 
        
          
            210
          
        
        , the first interface surface area 
        
          
            220
          
        
         of the exposed portion 
        
          
            216
          
        
         is formed by raised portions, non-planar surfaces, discontinuous surfaces and other structures that define a surface area significantly less than the potential contact surface area. Therefore, the exposed portion 
        
          
            216
          
        
         can be easily removed from the substrate 
        
          
            22
          
        
         to form a pull tab for removing the stretch releasing adhesive tape 
        
          
            210
          
        
        .
      
    
    
      
        
          FIG. 12
        
         illustrates a roll 
        
          
            250
          
        
         of a stretch releasing adhesive 
        
          
            252
          
        
         in accordance with the present invention. In the illustrated embodiment, release liner 
        
          
            254
          
        
         is located on the stretch releasing adhesive tape 
        
          
            252
          
        
         to facilitate unrolling. Frangible connections 
        
          
            256
          
        
         may optionally be formed in the stretch releasing adhesive tape 
        
          
            252
          
        
         to facilitate removal of sections without the use of a cutting instrument. Frangible connections 
        
          
            256
          
        
         may be a perforation, slit, cut or other locations of weakness along the length of the stretch releasing adhesive tape 
        
          
            252
          
        
        .
      
    
    
      
        
          FIG. 13
        
         is an alternate roll 
        
          
            260
          
        
         of a stretch releasing adhesive tape 
        
          
            262
          
        
         in accordance with the present invention. The stretch releasing adhesive tape is spiral wound on a core 
        
          
            264
          
        
        . The core preferably includes a low adhesion surface or release liner to facilitate removal of the stretch releasing adhesive tape 
        
          
            262
          
        
        .
      
    
    
      
        Examples of materials suitable for use as liners include kraft papers, polyethylene, polypropylene, polyester or composites of any of these materials which can be coated with release agents such as fluorochemicals or silicone. U.S. Pat. No. 4,472,480 describes low surface energy perfluorochemical liners. The preferred liners are papers, polyolefin films, or polyester films coated with silicone release materials. Examples of the silicone coated release papers are Polyslik trade silicone release papers supplied by James River Co., H.P. Smith Division (Bedford Park, Ill.), and silicone coated papers supplied by DCP-Lohja Inc. (Willowbrook, Ill.).
      
    
    
      
        While several embodiments of the invention have been illustrated and described, it will be recognized that various changes and modifications may be made without deviating from the inventive concept set for the above. Any of the features of the various embodiments disclosed herein can be combined.
      
    
    
      
        The patents, patent documents, and patent applications cited herein are incorporated by reference in their entirety as if each were individually incorporated by reference. It will be apparent to those of ordinary skill in the art that various changes and modifications may be made without deviating from the inventive concept set forth above. Thus, the scope of the present invention should not be limited to the structures described in this application, but only by the structures described by the language of the claims and the equivalents of those structures.
      
    
  
             
            
                        Claims
        
                - 1. A stretch releasing adhesive tape article with differential adhesive properties in an uncompressed state and a compressed state, comprising:an elongated length of stretch releasing adhesive tape comprising at least one potential contact surface area, at least a portion of the potential contact surface area comprising an adhesive surface having at least one raised portion, the potential contact surface area comprising a first interface surface area in the uncompressed state and a second interface surface area substantially greater than the first interface surface area in the compressed state.
- 2. The article of claim 1 wherein a portion of the stretch releasing adhesive tape in the uncompressed state comprises a pull tab.
- 3. The article of claim 1 wherein the stretch releasing adhesive tape comprises a multi-layer structure.
- 4. The article of claim 1 wherein the stretch releasing adhesive tape comprises a structural member.
- 5. The article of claim 4 wherein the structural member is selected from one of a film, an elastic foam, an inelastic foam, a monofilament.
- 6. The article of claim 1 wherein the stretch releasing adhesive tape comprises a hollow portion.
- 7. The article of claim 1 wherein the stretch releasing adhesive tape is selected from the group consisting of a pressure sensitive adhesive tape with an elastic structural member, a pressure sensitive adhesive tape with a highly extensible and substantially inelastic structural member, and a solid pressure sensitive adhesive.
- 8. The article of claim 1 wherein the potential contact surface area in the uncompressed state comprises a non-planar structure.
- 9. The article of claim 1 wherein the potential contact surface area in the uncompressed state comprises a discontinuous surface.
- 10. The article of claim 1 wherein the potential contact surface area in the compressed state comprises a substantially continuous surface.
- 11. The article of claim 1 wherein the stretch releasing adhesive tape in the uncompressed state has a cross-section selected from the group consisting of circular, star-shaped, oval, and multi-faceted.
- 12. The article of claim 1 wherein the stretch releasing adhesive tape in the uncompressed state comprises a geometric shape that provides less surface area in the uncompressed state than in the compressed state.
- 13. The article of claim 1 wherein the potential contact surface area comprises a rectangular cross-section of stretch releasing adhesive tape twisted to form helical ridges.
- 14. The article of claim 1 wherein the elongated length of stretch releasing adhesive tape comprises a roll of stretch releasing adhesive tape.
- 15. The article of claim 1 comprising a release liner adhered to the potential contact surface area.
- 16. The article of claim 1 comprising frangible connections formed intermittently along the stretch releasing adhesive tape.
- 17. The article of claim 1 wherein the stretch releasing adhesive tape comprises adhesive on the entire potential contact surface area.
- 18. The article of claim 1 wherein the potential contact surface area comprises adhesive regions and non-adhesive regions.
US Referenced Citations (4)
            
                
                    
                        | Number | Name | Date | Kind | 
                
                
                        
                            | 4024312 | Korpman | May 1977 | A | 
                        
                            | 4472480 | Olson | Sep 1984 | A | 
                        
                            | 5516581 | Kreckel et al. | May 1996 | A | 
                        
                            | 5650215 | Mazurek et al. | Jul 1997 | A | 
                
            
            Foreign Referenced Citations (5)
            
                
                    
                        | Number | Date | Country | 
                
                
                        
                            | 33 31 016 | Jul 1992 | DE | 
                        
                            | WO 9506691 | Mar 1995 | WO | 
                        
                            | WO 9806652 | Feb 1998 | WO | 
                        
                            | WO 9821285 | May 1998 | WO | 
                        
                            | WO 9931193 | Jun 1999 | WO |