Sheet with Selectively Activated Adhesive
An index card assembly which allows selective adherence of an index card to a mounting surface is disclosed. A base paper layer of the index card has a front side and an opposite back side. The paper layer has an upper edge with a portion of the paper layer removed to define a paperless zone which includes a gap across the upper edge. A cover layer having an outer face and an inner face is adhered by pressure sensitive adhesive disposed on its inner face to the front side of the paper layer. The cover layer is aligned to cover the paperless zone with a top of the cover layer extending across the gap of the paperless zone. The adhesive on the inner face of the cover layer is thus exposed across the paper zone on the back side of the paper layer. The thickness of the paper layer prevents the adhesive from contacting a surface abutting the back side of the paper layer in the absence of the application of a threshold level of pressure against the outer face of the cover layer.
This invention relates to articles which can be selectively secured to a mounting substrate by pressure sensitive adhesive. More particularly, this invention relates to a substrate in sheet form such as an index card having a writeable surface on one side and a mounting surface on a second opposite side, with a securing mechanism operable via a pressure threshold adhesive mechanism which is selectively exposed on the mounting side of the first substrate. Dependent upon a level of threshold pressure applied to the securing mechanism, the exposed pressure sensitive adhesive is either spaced from the mounting substrate or the article is deformable to bring the pressure sensitive adhesive into article securing engagement with the mounting substrate.
Memories are imperfect. Thus, we often write down things we want to remember at a later date. This may be a grocery list, a “to do” list, a speech, study notes, or other information we do not want to forget. For example, a student may take a series of blank index cards and turn them into “flash cards” by writing information on one (or both) sides of each card in preparing for an examination. An individual giving a speech may record notes for that speech on a series of index cards which can be stacked and easily transported or even pocketed. The ubiquitous Post-it® brand notes available from 3M Corporation have also proved quite useful for noting information to be recalled at a later date. A Post-it® brand note is a sheet of paper bearing a band of repositionable pressure sensitive adhesive across a back side thereof. A Post-it® brand note can be mounted on any number of surfaces, such as, for example, another sheet of paper, a wall, a mirror, a computer monitor, refrigerator door, etc. Post-It® brand notes are traditionally distributed in pad form, with adjacent notes adhered to one another by the repositionable pressure sensitive adhesive thereon. The notes stick together whenever placed adjacent one another, and thus are not easily shuffled or rearrangeable in stacked form without peel separation of the adhesive therebetween.
Index cards come traditionally in 3×5 inch or 4×6 inch formats and are typically made from stiff, more durable paper than note paper. There is no adhesive on an index card and it is easily shuffled among a stack of index cards. To stick an index card on a wall or other surface, adding a separate strip of tape may be used. However, it would be desirable to selectively adhere an index card to a surface (such as a wall, sheet of paper or the like) yet retain the ability to shuffle a stack of such index cards (i.e., not have adjacent index cards always adhere together) without having to go to the trouble of removing a tape strip from each index card.
BRIEF SUMMARY OF THE INVENTIONA sheet which may be selectively secured to a mounting surface includes at least a first substrate having a writeable surface on one side thereof and a mounting surface on a second opposite side thereof. The sheet also includes a securing mechanism including a pressure threshold adhesive mechanism which includes pressure sensitive adhesive exposed on the mounting side of the first substrate. In the absence of a threshold level of pressure applied to the securing mechanism, the pressure sensitive adhesive is spaced from the mounting substrate. The sheet is deformable such that a threshold level of pressure applied to the securing mechanism brings the pressure sensitive adhesive into sheet securing engagement with the mounting substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
While the above drawing figures set forth several embodiments of the invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention. The figures may not be drawn to scale. Like reference numbers have been used throughout the figures to denote like parts.
DETAILED DESCRIPTION In sheet form, a substrate has two major and generally planar sides.
While the present invention is applicable to any article in sheet form such as a sheet of paper, it is illustrated herein by index or note card embodiments and examples. A typical index card is made of paper, such as 90 pound weight paper, and is 0.0075 inches thick. Index cards come in two typical sizes, 3×5 inches and 4×6 inches. An index card may have rounded edges (such as illustrated in
The base layer 21 may be formed from sheet material such as paper, card stock, cardboard, plastic film, or some combination or laminate of such materials. Adjacent its upper edge 28, the layer 21 has a portion 40 removed therefrom to define an aperture therethrough which constitutes a paperless zone 42. This paperless zone 42 may take a number of forms, as illustrated herein. In one embodiment, the paperless zone 42 has a depth D and is elongated along upper edge 28 and includes an edge gap 44 of length L. In the embodiment illustrated in
A cover layer 50 is adhered to the front side 22 of the base layer 21 of the index card 20 and extends over the paperless zone 42. The cover layer 50, as seen in
A thickness T (
The layered arrangement disclosed above defines an index card assembly having a securing mechanism for allowing selective adherence of the index card 20 to a mounting substrate. As seen in
The deformed portion of the cover layer 50 is shown as portion 50a, which is deformed or bowed at edge portions 75 to bring the adhesive 56 thereon into adhering engagement with the mounting surface 72. In this manner, the index card 20 may be affixed to a wall, window or other vertically oriented surface and will be retained there by the adhesive 56. Thus, one can stick an index card up for study or memory purposes. Upon removal of the index card 20 from the substrate 70, the cover layer 50 reverts to the form illustrated in
In one embodiment, the cover layer 50 is formed from a polymer film which is deformable upon application of the threshold level of pressure to urge the adhesive 56 thereon into contact with a mounting surface (as seen in
The adhesive in all embodiments disclosed herein is applied to its supporting surface in a generally uniform thickness, and may be a permanent or repositionable pressure sensitive adhesive. The use of a repositionable pressure sensitive adhesive allows the index card to be adhered to a mounting surface multiple times without leaving any appreciable adhesive residue behind, and allows for the easy rearrangement of the relative positions of the index cards, which may be, for example, adhered upon a wall. Essentially, the present invention provides a means for sticking and holding index cards on another surface “on demand”.
For adhesion purposes, improved adherence appears to be attained when the paperless zone includes an open edge across which adhesive may be disposed (i.e., the edge gap 44). In other words, the paperless zone 42 is not surrounded on all sides by portions of the layer 21. The edge gap 44 provides an area of adhesive 56 which is spaced linearly from any edge or portion of the layer 21 having a thickness T, and thus facilitates the deformation of the cover layer 50 and the adherence of the adhesive 56 on the cover layer 50 to a mounting substrate surface.
The index card 20 of
As can be appreciated, the shape of the paperless zone on an index card assembly of the present invention can take many forms, and there can be multiple exposed adhesive zones. While the shape or shapes of the paperless zone(s) may be defined in part by ornamental considerations, each paperless zone is formed to provide an edge gap across the upper edge, side edges or bottom edge of the index card of sufficient distance that the cover layer can be deformed against a mounting surface and not be unduly constrained in that deformation by a nearby thickness of a portion of the base layer of the index card. On the other hand, when the cover layer is not deformed by an application of sufficient pressure, the adhesive is spaced from (i.e., recessed into) the back side of the index card.
In the embodiments of the present invention discussed above, only one side of the index card assembly is selectively self-adhereable to a mounting surface using recessed and exposed adhesive. In an index card 520 embodiment illustrated in
A layer of pressure sensitive adhesive 657 (like the adhesives disclosed above) is disposed in the recess 627. However, an exposed surface 659 of the adhesive 657 is spaced from the back side 624 of the base layer 621 so that the adhesive 657 does not engage a surface which is merely in abutting engagement with the back side 624. The index card 620 is caused to be adhered to a substrate 670 having a mounting surface 672 (
A layer of pressure sensitive adhesive 657a is disposed in the recess 627a. An exposed surface 659a of the adhesive 657a is spaced from the back side 624a of the base layer 621a (which is otherwise free of adhesive) so that the adhesive 657a does not engage a surface which is merely in abutting engagement with the back side 624a. The index card 620a is caused to be adhered to a substrate 670a having a mounting surface 672a (see
In this embodiment, the recess 627a extends across the entire back side 624a of the index card 620a, from the side edge 632 to the side edge 634, as seen in
A feature common to all of the embodiments disclosed herein is that pressure sensitive adhesive is exposed on a portion of the back side of a substrate in sheet form. In some embodiments, the pressure sensitive adhesive is exposed through a portion which has been removed from the base layer of the substrate to define an aperture or paperless zone. In other embodiments, the adhesive is exposed by being disposed within a recess provided on the back side of the base layer. In further embodiments, the adhesive is disposed on the back side of the base layer, and effectively “recessed” by means of one or more raised standoff elements which extend from the base layer to a height taller than the exposed face of the adhesive thereon. The standoff elements may constitute the back face of the base layer itself (such as in the embodiment of
In all embodiments disclosed herein and contemplated, the essential functional attributes are the same. When the base layer has its back side abutting another surface, it will not adhere thereto because the pressure sensitive adhesive thereon is spaced from that surface. When a threshold level of pressure is applied to the front side of the base layer, opposite the pressure sensitive adhesive thereon, the layer bearing the adhesive is sufficiently flexible and deformable so that at least a portion of the exposed adhesive is brought into an abutting engagement with the surface to adhere thereto. The threshold level of pressure would typically be manual, such as by pressing against the outer face of the layer bearing the adhesive layer with a finger or thumb of a user. This externally applied pressure (i.e., compressive force) would typically be exerted in a direction substantially normal to the base layer. This pressure creates an adhesion peel force of the adhesive after activation by the user which is greater than the adhesion peel force (which is zero) exhibited prior to activation by the user and which is sufficient to adhere the index card to a target mounting surface. The threshold level of pressure can vary, dependent upon the nature of the material of the layer bearing the adhesive (e.g., its resiliency), the thickness of the base layer, the aggressiveness of the adhesive and the nature of the surface to which the index card is being adhered, among other things. Another feature of all of the embodiments disclosed herein is that multiples of each base layer embodiment may be stacked or shuffled without the base layers sticking to one another (without an application of pressure normal to the plane of the base layers). This allows the base layers (for example, in the form of index cards) to be reordered in a stack without sticking to one another, so that the order of cards in the stack can be easily rearranged by a user. The “shuffleability” of base layers may be enhanced by providing a coating of a slip-enhancing adhesive release layer on a portion or on all of the front side of the base layer. In addition, when an appropriate adhesive is used, the base layer can be adhered to a surface, and then removed and reapplied to the same surface in a different location or to a different surface, as desired by the user, with leaving any appreciable adhesive residue on those surfaces once removed. As also noted above, in all embodiments herein both sides of the base layer are writeable, i.e., adaptable to accept writing or other indicia from a pencil, pen, highlighter, crayon or from other indicia forming articles such as a printer.
The base layer 721 may be formed from sheet material such as paper, card stock, cardboard, plastic film, or some combination or laminate of such materials. In most of the embodiments disclosed herein, a layer of pressure sensitive adhesive is disposed relative to the back face of the base layer adjacent its upper edge. In the embodiment shown in
The standoff distances S1 and S2 of the raised elements 761 and 765, respectively, are sufficient to space or separate the exposed surface 759 of the adhesive 756 on the back side 724 of the base layer 721 from contacting an adjacent surface. Thus, the inventive note card 720 can be handled and moved across an adjacent surface such as a sheet of paper, a desktop, a countertop or other like note cards without adhering thereto by the adhesive 756. Any contact by the note card 720 with the adjacent surface is via the upper and lower standoff surfaces 763 and 767, and via portions of the back side 724 of the base layer 721 which are free of adhesive. The raised elements 761 and 763 effectively provide borders for a recess zone 769 therebetween where the exposed surface 759 of the adhesive 756 is disposed. The space between the raised elements 761 and 765 is shown in
The arrangement disclosed in
In
The upper and lower raised elements may be formed in a variety of ways and from a variety of materials. For instance, the upper and lower raised elements may be a discreet layer of a sheet material, a layer of tape material, or a layer of a coating material that has been applied, such as illustrated in
Another example of the formation of upper and lower raised elements is illustrated in
In the embodiments illustrated in
Another alternative means for forming a plurality of discreet standoff elements is illustrated in
As the note card 720e is used (i.e. the adhesive is activated by pressure, peeled off a surface and then reactivated by pressure again, perhaps multiple times), the upper and lower raised elements 761e and 765e can decrease in height because they are deformed when pressed against a mounting surface to activate the adhesive 756. However, the upper and lower raised elements 761e and 765e do not become, over use, so decreased in height that they fail to maintain a sufficient standoff distance for the adhesive 756.
In a note card 720e of the form shown in
In the embodiments of the present invention discussed above, the inventive index or note card does not require manipulation by a user to define the requisite standoff distance on the back side thereof for use. For example, note card assembly shown in the embodiments 1-14 is formed with the adhesive recessed from unintended contact with an abutting surface of the back side of the note card. In the embodiments of
In alternative embodiments, some degree of user manipulation may be required to define the standoff distance on the back side of a note card. For example, the embodiment illustrated in
The base layer 821 has a cut 831 therethrough, formed within the band of adhesive 856. The cut 831 extends from a first end 833 on the score line 829 toward the upper edge 828 of the base layer 821 to a first turn 835. The cut 831 then has a portion 837 which extends parallel to the upper edge 828 of the base layer 821 (and is spaced therefrom) which extends to a second turn 839. The cut 831 then extends from the second turn 839 away from the upper edge 828 of the base layer 821 to a second end 841 of the cut 831 which is on the score line 829. The first end 833 and the second end 841 of the cut 831 are spaced apart across the base layer 821, as illustrated in
That portion of the base layer 821 defined by the upper edge 828 thereof, the cut 831 and the score line 829 (on each outer side of the cut 831) is defined as a spacing portion 845 of the base layer 821. The spacing portion 845 may be folded over along a score line 829 and adhered against the back side 824 of the base layer 821 by the adhesive thereon, so that the note card 820 takes on the form illustrated in
The thickness of the spacing portion 845 of the base layer 821 thus defines a standoff distance S3 (see
As noted above, the essential securing mechanism functional attributes of the note card 820 are like those of the other embodiments disclosed herein. When the base layer 821 has its back side 824 abutting another surface, it will not adhere thereto because the pressure sensitive adhesive 856 thereon (on the non-folded tab portion 847) is spaced from that surface. When a threshold level of pressure is applied to the front side 822 of the base layer 821 (on the front side of non-folded tab portion 847), the base layer 821 is sufficiently flexible and deformable so that at least a portion of the exposed adhesive 856 is brought into an abutting engagement with a surface to adhere thereto. In addition, when an appropriate adhesive is used, the base layer can be adhered to a surface and then removed and reapplied to the same surface in a different location or to an altogether different surface, as desired by the user, without leaving any residue on those surfaces once removed. With the spacing portion 845 folded over and adhered to the back side 824 of the base layer 821 (as illustrated in
In this embodiment, when the index card 820 is in its unfolded state (as illustrated in
A spacing portion 845a is defined by the upper edge 828, the cut 831 and the score line 829. The spacing portion 845a can be folded over along the score line 829 and adhered to the back side 824 of the base layer 821 via the adhesive 856a thereon.
Although the band of adhesive 856a is in a different location in the embodiments of
Once the note card 820a has been placed in its folded over configuration (
Another embodiment of the inventive article of the present invention as illustrated in
A layer of pressure sensitive adhesive 956 is applied to the back side 924 of the base layer 921. The layer of adhesive may be applied in a continuous band or in discrete and separated zones of adhesive, such as adhesive zones 956a, 956b, and 956c. In one embodiment, those adhesive zones may be defined by the shape of a spacer layer 911 applied over or adjacent the adhesive 956. The spacer layer 911 may be formed from a sheet of material adhered to the adhesive 956, or a separately adhereable tape material, or a coating of masking material which is applied over the back side 924 of the base layer 921.
In the embodiment illustrated in
The standoff distance S5 is sufficient to space or separate the exposed surface 959 of the adhesive 956 on the back side 924 of the base layer 921 from contacting an adjacent surface. Thus, the inventive note card 920 can be handled and moved across an adjacent surface such as a sheet of paper, a desktop, a countertop, or other like note cards without adhering thereto by the adhesive 956. The spacer layer 911 may be formed to have lower depending sections 916 which may or may not extend below a lowermost edge 951 of the adhesive 956. The height of the spacer layer 911 relative to the height of the exposed surface 959 of the adhesive 956 (spacing distance S5) and the shape of the spacing layer 911 relative to the shape of the exposed surface 959 of the adjacent adhesive 956 may be varied, but must be maintained in a relationship so that the securing mechanism function of the note card 920 is achieved. In other words, the note card 920 is shuffleable with respect to other like note cards, and can be laid against a mounting surface without adhering thereto, in the absence of the application of a level threshold pressure on the front side of the base layer opposite the exposed surface of the adhesive.
The pattern of a spacer layer or raised element relative to the exposed surface of the adhesive illustrated by the embodiment of
In
A layer of pressure sensitive adhesive 1056 is applied to the back side 1024 of the base layer 1021. The layer of adhesive may be applied in a continuous band or in discreet and separated zones of adhesive, such as adhesive zones 1056a, 1056b, 1056c, etc. The shape of the adhesive zones may be defined by the shape of one or more raised elements 1061 spaced apart across the back side 1024 of the base layer 1021, from side edge 1032 to side edge 1034. In the exemplary embodiment illustrated in
In all forms of the raised element 1061, it serves the same standoff function as the raised elements or spacer layers described above, namely that the height of each raised element 1061 is taller than the height of an exposed surface 1059 of the adhesive 1056, with the differential in height being sufficient to space or separate the exposed surface 1059 of the adhesive 1056 from contacting a target or adjacent surface and adhering thereto, without the application of a threshold level of pressure. In other words, a “recess” is defined between adjacent raised elements 1061 for the exposed surface 1059 of the adhesive 1056.
A layer of pressure sensitive adhesive 1156 is applied to the back side 1124 of the base layer 1121. The layer of adhesive 1156 may be applied in a continuous band or in discrete and separated zones of adhesive, such as adhesive zones 1156a, 1156b, 1156c, 1156d, etc. (as noted above, such adhesive zones may be defined by the shape of one or more raised elements, such as exemplary raised elements 1161 and 1165 applied over or adjacent the adhesive 1156). The raised elements may be formed from a sheet of material adhered to the adhesive 1156, or a separately adhereable tape material, or a coating of masking material such as a varnish which is applied over the back side 1124 of the base layer 1121.
In the embodiment illustrated in
In one embodiment, a single raised element (such as raised element 1165) may be sufficient to provide the necessary standoff distance between an exposed surface 1159 of the adhesive 1156 and an abutting surface such as another note card or a wall or countertop. The raised elements, whether one raised element or more, are formed to define an effective “recess” for the exposed surface 1159 of the adhesive 1156 so that the inventive sheet has the “on-demand” pressure adhesion characteristic desired, yet is also shuffleable in the absence of the application of a threshold level of pressure against the front side of the sheet, opposite the adhesive thereon.
While the raised elements shown, for example, in
The operative layer bearing the adhesive which must deform to allow the adhesive to overcome the recess defined for it and to contact the target surface, must be sufficiently flexible to allow such contact and then resilient enough to resume its substantially original shape to allow the recess to be redefined once it is removed from the target surface. For the embodiments where the base layer serves this purpose, a base layer having a thickness of 0.004 inches to 0.010 inches is suitable, and more preferably from 0.004 inches to 0.008 inches, and most preferably 0.0075 inches. The standoff distance is another factor which affects the functional characteristics of the inventive sheet assembly. Standoff distances from 0.0005 inches to 0.010 are suitable, more preferably 0.002 inches to 0.006 inches, and even more preferably 0.0015 inches to 0.0025 inches. The spacing between separate raised elements, or between portions of a spacer layer defining a recess therebetween, is also a characteristic which serves to define the functional attributes of the inventive sheet assembly. Such a spacing distance may range from 0.25 inches to 0.75 inches, more preferably from 0.375 inches to 0.625 inches. As discussed above, other factors will influence the operability of the pressure threshold adhesive mechanism of the securing mechanism of the present invention, such as the aggressiveness of the adhesive that is used and the presence and characteristics of a slip resistant adhesive release coating that may be applied to the front side of the sheet. The shapes and relationships of the raised elements, recesses and spacer layers shown herein are merely exemplary, and not intended to limit the invention to a particularly disclosed orientation or arrangement.
The present invention is further illustrated by the following examples, but the particular apparatus and processes recited in this example, as well as other conditions and details should not be construed to unduly limit this invention. All materials and components are commercially available or known to those skilled in the art unless otherwise stated or apparent. These examples are illustrative in nature and are not intended to limit the invention in any way.
EXAMPLE SET A As noted above, a number of variations can be made to the design of an inventive index card assembly without sacrificing utility. One specific example of an index card of the present invention would be a 3×5 inch card made of card stock. The card stock is 90 pound weight paper, which is 0.0075 inches thick. The corners are rounded with a 0.25 inch radius. The index card has printed blue lines on its front side for writing spaced horizontally across the longer dimension (5 inch dimension of the index card). The paperless zone along the upper edge of the index card is centered and has an edge gap (L) of approximately 2 inches. The paperless zone has a depth (D) of 0.438 inches, and has rounded interior corners of 0.50 inch radius, assuming a shape similar to that illustrated in
Static Angle Test (Sat) for Wall Hang
The static angle test is an applied load peel test where the peel angle and applied force are constant. The test measures the holding power of an adhesive sheet to a nearly vertical surface. Adhesive test samples of paper were cut to two inches wide and three inches in length. The adhesive strip on the back face of each sample is positioned so that it is parallel to the short dimension of the sheet, near its upper edge. Samples were equilibrated at constant temperature (22° C.) and humidity (50%) for at least 24 hours prior to testing. The sample, adhesive stripe facing down, was placed on a horizontal test surface of a clean painted steel panel by aligning the adhesive stripe parallel to the top edge of the rectangular steel test panel. The adhesive bond is created with one cycle (two passes) of a 1.5 lb. sample roller (1.5 lb., 1.75 inch wide, radius of 1.875 inch, covered with a hard rubber coating). For each sample, data was collected with two different roll-down methods. The first method, called the “Shuffled” mode, simulates applying an even pressure from side-to-side across a front face of the sheet, which should not activate the adhesive. In this method, the roller was cycled directly over the adhesive stripe, and standoffs, in a direction parallel to the adhesive stripe and standoffs. As a result of the width of the roller being wider than the spacing between the standoffs, the roller spanned the standoffs and thus did not force the adhesive into contact with the test surface of the steel panel below. The “Activated” mode is the second roll-down method. In this case, the roller was cycled in a direction perpendicular to the adhesive stripe. In this case, the diameter of the roller is sufficiently small to fit between the standoffs, thus displacing the paper and forcing the adhesive into contact with the test surface of the steel panel.
In both cases, the panel with the affixed sample was then disposed with its test surface at an acute angle of 60 degrees relative to horizontal, and a 100 g weight was immediately attached to the non-adhered lower edge of the sample which had been adhered to the test surface. The time to failure (sample falling from the panel) was measured in seconds for each of four replicates. A different panel and sample was used for each replicate. The failure times were averaged for analysis.
Lap Shear Test
The lap sheet test method measures the force required to break an adhesive bond between sheets in shear under tension loading. An adhesive bond was created between two similar samples of the selectively activated sheet. Sheet test specimens were cut to two inches wide and three inches in length. A stripe of adhesive was placed on a back face of each sheet parallel to the short dimension of the sheet, near the upper edge. Specimens were equilibrated at constant temperature (22° C.) and humidity (50%) for at least 24 hours prior to testing. A lap adhesive bond was created between sheets by aligning a first adhesive-backed sheet above a similar second adhesive-backed sheet, with the adhesive stripes facing down for both sheets. The top inch of the first sheet, which contained the adhesive strip, overlaped the bottom inch of the second sheet. The adhesive bond was created with one cycle (two passes) of a 1.5 lb sample roller. Data were collected for each sample by rolling in the Shuffled and Activated modes, as described above.
The bonded assembly was tested in tensile mode at a separation speed of one inch per minute, using a Sintech mechanical tester (available from MTS System Corporation, Eden Prarie, Minn.). The peak load was recorded and averaged for four replicates.
Materials
The samples in the examples described below were constructed using Post-it® Restickable Index Cards, catalog number 6351; Post-it® Notes, catalog number 655; and Scotch® Magic Tape, catalog number 810, all available from 3M Company, St. Paul, Minn. The index cards samples are paper approximately 7.5 mils in thickness, three inches wide and five inches long. The paper is a 108 pound tag stock. A 0.6875 inch wide repositionable adhesive stripe is coated along the length of the long dimension of the sheet, adjacent to an upper edge thereof. In the unaltered form, the sheets do not have a selectively activated adhesive and consequently do not easily shuffle (i.e., they stick together). The sheet samples formed from Post-it® Notes samples are similar to the index card sheet samples except that the paper thickness is 0.004 in and is a 20 pound bond. On the Post-it® Notes samples, the adhesive stripe is 0.6 inch wide along an upper edge of the sheet.
Selectively activated adhesive sheets were produced by laminating strips of Scotch® Magic tape to the index cards samples and the Post-it® Notes samples to produce standoffs of varying heights and separation spacings (adhesive stripe width), in formats similar to the sheet layout shown in
Tabs 1 and 2 illustrate the affect of standoff height on the ability to produce a selectively activated adhesive sheet. The dimensions and placement of the standoffs of each sample sheet are shown in Table 1. Example A had no standoffs at all. For Examples 1 and 2, the “upper” standoff was positioned along the top edge of the sheet on top of the adhesive stripe. The “lower” standoff was positioned parallel to the upper standoff, at distance equal to the adhesive stripe width perpendicular to the upper standoff. Although the standoff widths are not exactly equal, the variation shown does not dramatically affect the performance of the card.
For Example A, the Activated and Shuffled modes produce similar responses. In both modes the sample sheets displayed moderate adhesion to another card and to a vertically suspended panel. The relatively large lap shear force and static angle hang time in the Shuffled mode indicates that the card will not shuffled satisfactorily. As shown in Examples 2 and 3, the addition of a standoff to both sides of the adhesive stripe allows the adhesive to be activated in some cases, as indicated by the differing performance between the two modes. When compared to Example A, the lap shear force and static angle hang time is significantly reduced in the Shuffled mode for Examples 2 and 3, which permitted shuffling of the sample sheets. Although the lap shear force and static angle hang times in the Activated mode are reduced for Examples 1 and 2, as compared to Example A, they are sufficient to adhere the sample sheet to a surface if desired. Increasing the standoff height spaces the adhesive further away from the bonding surface, and is thus more difficult to activate the adhesive, as indicated by the reduced lap shear forces and static angle holding times for both modes.
EXAMPLES 3-5Examples 3-5 illustrate the affect of the distance between standoffs on the ability to produce a selectively activated adhesive sheet. The dimensions and placement of the standoffs of each example are shown in Table 3. The “upper” standoff was positioned along the top edge of the sheet on top of the adhesive stripe. The “lower” standoff was positioned parallel to the upper standoff, at distance equal to the adhesive stripe width perpendicular to the upper standoff.
The test results, for Example 3-5 are shown in Table 4. Increasing the distance between the standoffs allows more of the adhesive area to contact a bonding surface, thus increasing the lap shear force and static angle holding times. Example 3 illustrates that an adhesive stripe width of 0.25 inch is not sufficiently large enough to activate the adhesive using the roll down method described. Although samples of this sheet shuffled well, they did not display sufficient ability to adhere and hang on a vertical surface.
Tables 5 and 6 illustrate the affect of paper thickness on the ability to produce a selectively activated adhesive sheet. The sample sheet dimensions are shown in Table 5. Examples A and B had no standoffs at all, where Example A is an index card sample and Example B is a note sheet sample. Test results are shown in Table 6. The difference in lap shear force and static angle holding time for both modes between Example 6 and Example A is larger than that between Example 7 and Example B as a result of the increased paper thickness. As the stiffness of the sample paper was decreased, the ability to form an adhesive bond for both modes increased and ultimately rendered the sheet unshuffleable. Examples 6 and 7 have large lap shear forces and static angle holding times in the Activated modes, relative to Examples A and B, respectively, and correspondingly low values in the Shuffled mode, which enable the sheets to be shuffled and also mounted to a surface.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
Claims
1-41. (canceled)
42. A sheet which may be selectively secured to a mounting substrate comprising:
- a first substrate having a writeable surface on one side thereof and a mounting surface on a second opposite side thereof; and
- pressure layer including pressure sensitive adhesive exposed on the second side of the first substrate, and a standoff element on the second side of the first substrate, the standoff element having a height greater than a height of the adhesive,
- wherein in the absence of a threshold level of pressure applied to the pressure layer, the pressure sensitive adhesive is spaced from the mounting substrate, and
- wherein the sheet is deformable such that a threshold level of pressure applied to the pressure layer brings the pressure sensitive adhesive into sheet-securing engagement with the mounting substrate.
43. The sheet of claim 42 wherein the pressure layer comprises:
- the first substrate having an aperture defined therein; and
- a second substrate having a first adhesive face and a second pressure face, the first adhesive face being adhered to the writeable surface of the first substrate and extending across the aperture,
- wherein the second substrate is deformable such that a threshold level of pressure applied to the pressure face thereof brings the adhesive into contact with the mounting surface.
44. The sheet of claim 43 wherein the aperture is open along one edge of the first substrate.
45. The sheet of claim 43 wherein the second pressure face of the second substrate bears indicia.
46. The sheet of claim 42 wherein upon removal of the sheet from the mounting substrate, the pressure layer substantially returns to its original undeformed shape.
47. The sheet of claim 42 wherein the first substrate is selected from a group consisting of paper, card stock, cardboard, plastic film, and combinations thereof.
48. The sheet of claim 42 wherein the first substrate has an upper edge with a portion of the first substrate being removed to define a paperless zone which includes a gap across the upper edge; and wherein the pressure layer includes a cover layer having an outer face and an inner face, the cover layer having pressure sensitive adhesive disposed on its inner face, with the cover layer adhered thereby to the writeable surface of the first substrate to cover the paperless zone in an alignment where a top edge of the cover layer extends across the gap of the paperless zone and the adhesive on the inner face of the cover layer is exposed across the paperless zone on the second side of the first substrate.
49. The sheet of claim 48 wherein the standoff element comprises a portion of the first substrate which has a thickness and the cover layer is sufficiently flexible to bow across the thickness and the paperless zone to place at least a portion of the adhesive exposed thereon into adhering contact with the mounting substrate.
50. The sheet of claim 45 wherein the indicia includes color.
51. The sheet of claim 42 wherein the adhesive is a repositionable pressure sensitive adhesive.
52. The sheet of claim 42 wherein the standoff element comprises a portion of the first substrate which has a thickness sufficient to space the adhesive exposed on the cover layer from a surface in abutting engagement with the second side of the first substrate, in the absence of a pressure applied to the outer face of the cover layer urging it toward the surface.
53. The sheet of claim 52 wherein a plurality of said sheets aligned in a stacked orientation fail to adhere together, absent the application of pressure to the outer faces of their respective cover layers.
54. The sheet of claim 42 wherein the standoff element comprises:
- a first generally linear raised element on the second side on the first substrate; and
- a second generally linear raised element on the second side of the first substrate, the second raised element aligned generally parallel to and spaced from the first raised element,
- wherein at least a portion of the pressure sensitive adhesive exposed on the second side of the first substrate is between the first and second raised elements and has a height lower than the first and second raised elements.
55. The sheet of claim 54 wherein each of the raised elements may be selected from the group consisting of a continuous strip, a discontinuous strip, a bead, a plurality of beads, a rib of the first substrate, a plurality of ribs of the first substrate, a plurality of peaks of the first substrate, and combinations thereof.
56. The sheet of claim 42 wherein the first substrate has an upper edge, and wherein the pressure layer comprises:
- a score line on the first substrate which is spaced from and parallel to the upper edge of the first substrate; and
- a cut formed through the first substrate, the cut extending from a first end on the score line toward the upper edge to a first turn, extending from the first turn along and spaced from the upper edge to a second turn, and then extending from the second turn away from the upper edge to a second end of the cut on the score line.
57. The sheet of claim 56 wherein the cut has a portion thereof which extends parallel to the upper edge of the first substrate.
58. The sheet of claim 56 wherein a spacing portion of the first substrate is defined by the upper edge thereof, the score line, and the cut.
59. The sheet of claim 58 wherein the pressure layer further comprises:
- the adhesive being disposed on the second side of the first substrate above the score line; and
- the spacing portion of the first substrate being folded over so that the adhesive thereon is bonded to the second side of the first substrate, thereby defining an upper non-folded tab portion of the first substrate bearing adhesive, and thereby forming a raised layer on the second side of the first substrate which defines the standoff element and which has a thickness sufficient to space the adhesive on the tab portion from the mounting substrate in the absence of the threshold level of pressure.
60. The sheet of claim 58 wherein the pressure layer further comprises:
- the adhesive being disposed on the second side of the first substrate below the score line; and
- the spacing portion of the first substrate being folded over so that at least a section thereon is bonded to the second side of the first substrate by the adhesive, with the folded over spacing portion forming a raised layer, relative to adhesive exposed adjacent thereto, which defines the standoff element and which has a thickness sufficient to space the adhesive exposed from the mounting substrate in the absence of the threshold level of pressure.
61. The sheet of claim 42 wherein the standoff element comprises a layer of masking material applied over portions of the adhesive.
62. The sheet of claim 42 wherein the pressure layer comprises:
- a recess formed on the second side of the first substrate, the first side of the first substrate having no surface discontinuities relative to the recess, and the adhesive on the second side of the first substrate is disposed only within the recess, the recess having a depth, relative to an unrecessed portion of the second side of the first substrate, which is sufficient to space the adhesive from the mounting substrate in the absence of the application of the threshold level of pressure.
63. The sheet of claim 62 wherein the first substrate has an upper edge, and wherein the recess has an upper border which extends along and is spaced from the upper edge of the first substrate.
64. The sheet of claim 63 wherein the first substrate has first and second side edges, and wherein the recess extends across the first substrate from first side edge to the second side edge thereof.
65. The sheet of claim 42 wherein the exposed pressure sensitive adhesive has an edge on the second side of first substrate, and wherein the pressure layer comprises:
- a spacer layer of material on the second side of the first substrate adjacent the edge of the exposed pressure sensitive adhesive, the spacer layer having having a shape relative to the adhesive and having a height greater than a height of the adhesive, said shape and height of the spacer layer being sufficient to space the adhesive from the mounting substrate in the absence of the application of the threshold level of pressure.
66. The sheet of claim 54 wherein the first raised element is adjacent to and defines a first border for the pressure sensitive adhesive zone.
67. The sheet of claim 66 wherein the pressure sensitive adhesive zone is disposed on a first section of the substrate, and wherein the first section of the substrate is deformable such that a threshold level of pressure applied to the first side of the substrate brings the pressure sensitive adhesive zone into sheet-securing engagement with a mounting substrate.
Type: Application
Filed: Feb 4, 2005
Publication Date: Oct 25, 2007
Inventors: David Windorski (Woodbury, MN), Kenneth Hanley (Eagan, MN), Ronald Most (Black Canyon City, AZ), Stephen Gamradt (Cottage Grove, MN)
Application Number: 10/587,017
International Classification: B42F 15/06 (20060101);