U.S. patent application number 10/587017 was filed with the patent office on 2007-10-25 for sheet with selectively activated adhesive.
Invention is credited to Stephen L. Gamradt, Kenneth J. Hanley, Ronald W. Most, David C. Windorski.
Application Number | 20070248815 10/587017 |
Document ID | / |
Family ID | 34808601 |
Filed Date | 2007-10-25 |
United States Patent
Application |
20070248815 |
Kind Code |
A1 |
Windorski; David C. ; et
al. |
October 25, 2007 |
Sheet with Selectively Activated Adhesive
Abstract
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.
Inventors: |
Windorski; David C.;
(Woodbury, MN) ; Hanley; Kenneth J.; (Eagan,
MN) ; Most; Ronald W.; (Black Canyon City, AZ)
; Gamradt; Stephen L.; (Cottage Grove, MN) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Family ID: |
34808601 |
Appl. No.: |
10/587017 |
Filed: |
February 4, 2005 |
PCT Filed: |
February 4, 2005 |
PCT NO: |
PCT/US05/03594 |
371 Date: |
May 31, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10772190 |
Feb 4, 2004 |
|
|
|
10587017 |
May 31, 2007 |
|
|
|
Current U.S.
Class: |
428/343 |
Current CPC
Class: |
Y10T 428/28 20150115;
B42F 5/00 20130101; Y10T 428/24793 20150115; Y10T 428/1495
20150115; B42D 5/003 20130101 |
Class at
Publication: |
428/343 |
International
Class: |
B42F 15/06 20060101
B42F015/06 |
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.
Description
BACKGROUND OF THE INVENTION
[0001] 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.
[0002] 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.RTM.
brand notes available from 3M Corporation have also proved quite
useful for noting information to be recalled at a later date. A
Post-it.RTM. brand note is a sheet of paper bearing a band of
repositionable pressure sensitive adhesive across a back side
thereof. A Post-it.RTM. 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.RTM.
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.
[0003] Index cards come traditionally in 3.times.5 inch or
4.times.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 INVENTION
[0004] A 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
[0005] FIG. 1 is an embodiment of the present invention, in the
form of an index card, as viewed from a front major side
thereof.
[0006] FIG. 2 is a view of the index card of FIG. 1, from an
opposite back major side thereof.
[0007] FIG. 3 is a sectional view as taken along lines 3-3 in FIG.
1.
[0008] FIG. 4 is a sectional view as taken along lines 4-4 in FIG.
1.
[0009] FIG. 5 is top view of the index card of FIG. 4, as taken
along lines 5-5 in FIG. 4.
[0010] FIG. 6 is a sectional view of the index card of FIG. 4,
showing its adherence to a vertical substrate surface.
[0011] FIG. 7 is a top view of the index card and substrate of FIG.
6, as taken along lines 7-7 in FIG. 6.
[0012] FIG. 8 is a side elevational view of a stack of index cards
such as the index card illustrated in FIGS. 1-7, sitting on a
horizontal substrate surface with the exposed adhesive on each
index card not activated.
[0013] FIG. 9 illustrates a second embodiment of the present
invention, as viewed from the back side of an index card.
[0014] FIG. 10 illustrates a third embodiment of the present
invention, as viewed from the top of an index card.
[0015] FIG. 11 illustrates the index card of FIG. 10, as adhered to
a substrate surface.
[0016] FIG. 12 illustrates a fourth embodiment of the present
invention, as viewed from the back side of an index card.
[0017] FIG. 13 illustrates a fifth embodiment of the present
invention, as viewed from the back side of an index card.
[0018] FIG. 14 illustrates a sixth embodiment of the present
invention, as viewed from the front side of an index card.
[0019] FIG. 15 illustrates a seventh embodiment of the present
invention, as viewed from the back side of an index card.
[0020] FIG. 16 is a sectional view as taken along lines 16-16 in
FIG. 15.
[0021] FIG. 17 is a sectional view of the index card of FIG. 16,
showing its adherence to a vertical substrate surface.
[0022] FIG. 18 illustrates an eighth embodiment of the present
invention, as viewed from the back side of an index card.
[0023] FIG. 19A is a sectional view as taken along lines 19-19 in
FIG. 18.
[0024] FIG. 19B is a section view of the index card of FIG. 18,
showing its adherence to a vertical substrate surface.
[0025] FIG. 20 is a sectional view as taken along lines 20-20 in
FIG. 18.
[0026] FIG. 21 illustrates a ninth embodiment of the present
invention, as viewed from the back side of a note card.
[0027] FIG. 22A is a sectional view as taken along lines 22-22 in
FIG. 21.
[0028] FIG. 22B is a sectional view of the note card of FIG. 21,
showing its adherence to a vertical substrate surface.
[0029] FIG. 23 illustrates a tenth embodiment of the present
invention, in a sectional view like the sectional view taken along
lines 22-22 of FIG. 21.
[0030] FIG. 24 illustrates an eleventh embodiment of the present
invention, in a sectional view like the sectional view taken along
lines 22-22 of FIG. 21.
[0031] FIG. 25 illustrates a twelfth embodiment of the present
invention, as viewed from the back side of a note card.
[0032] FIG. 26 illustrates a thirteenth embodiment of the present
invention, as viewed from the back side of a note card.
[0033] FIG. 27A is a sectional view as taken along lines 27-27 in
FIG. 26.
[0034] FIG. 27B illustrates a fourteenth embodiment of the present
invention, in a sectional view like the sectional view as taken
along lines 27-27 in FIG. 26.
[0035] FIG. 28 illustrates a fifteenth embodiment of the present
invention, as viewed from the back side of a note card.
[0036] FIG. 29 is a sectional view as taken along lines 29-29 in
FIG. 28.
[0037] FIG. 30 illustrates a sixteenth embodiment of the present
invention, as viewed from the back side of a note card.
[0038] FIG. 31 illustrates the note card of FIG. 30, with a spacing
portion thereof folded down and adhered to the back side of the
note card.
[0039] FIG. 32 is a sectional view as taken along lines 32-32 in
FIG. 30.
[0040] FIG. 33 is a sectional view as taken along lines 32-32 in
FIG. 30, with the spacing portion of the note card partially
folded.
[0041] FIG. 34 is a sectional view as taken along lines 34-34 in
FIG. 31.
[0042] FIG. 35 is a seventeenth embodiment of the present
invention, as viewed from the back side of a note card.
[0043] FIG. 36 illustrates the note card of FIG. 35, with a spacing
portion thereof folded down and adhered to the back side of the
note card.
[0044] FIG. 37 is a sectional view as taken along lines 37-37 in
FIG. 35.
[0045] FIG. 38 is a sectional view as taken along lines 32-32 in
FIG. 35, with the spacing portion of the note card partially
folded.
[0046] FIG. 39 is a sectional view as taken along lines 39-39 in
FIG. 36.
[0047] FIG. 40 illustrates an eighteenth embodiment of the present
invention, as viewed from the back side of a note card.
[0048] FIG. 41 is a sectional view as taken along lines 41-41 in
FIG. 40.
[0049] FIG. 42 illustrates a nineteenth embodiment of the present
invention, as viewed from the back side of a note card.
[0050] FIG. 43 illustrates a twentieth embodiment of the present
invention, as viewed from the back side of a note card.
[0051] 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
[0052] In sheet form, a substrate has two major and generally
planar sides. FIGS. 1 and 2 illustrate a sheet in the form of an
index card 20 defined by a base layer 21 of material having a front
side 22 and an opposite back side 24. Typically, both sides are
writeable, i.e., adapted to accept writing or other indicia from a
pencil, pen, high lighter, crayon, or from other indicia forming
articles such as a printer. An index card will typically have, on
one side (such as front side 22), a plurality of ruled lines 26
pre-printed thereon. The base layer 21 has an upper edge 28, lower
edge 30, and left and right side edges 32 and 34, respectively.
[0053] 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.times.5
inches and 4.times.6 inches. An index card may have rounded edges
(such as illustrated in FIGS. 1 and 2), or may have squared off
corners (such as illustrated in FIGS. 30 and 35).
[0054] 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 FIGS. 1 and 2, the paperless zone 42 is
centered across the upper edge 28 of the base layer 21.
[0055] 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 FIGS. 3 and 4, has an outer
pressure face 52 and an inner adhesive face 54, and a layer of
pressure sensitive adhesive 56 is disposed on the inner face 54.
The pressure sensitive adhesive 56 serves to adhere the cover layer
50 to the front side 22 of the base layer 21 of the note card 20,
over and across the paperless zone 42 (which is shown in outline
form by dashed lines 58 under cover layer 50 in FIG. 1). The cover
layer 50 has a top edge 60 and a bottom edge 62, along with left
and right edges 64 and 66, respectively. The top edge 60 of the
cover layer 50 is aligned to extend across the edge gap 44 of the
paperless zone 42, as illustrated in FIGS. 1, 2, 4 and 5.
[0056] A thickness T (FIG. 4) of the base layer 21 is sufficient,
in the paperless zone 42, to space or separate the exposed adhesive
56 on the inner face 54 of the cover layer 50 from another surface
contacting the back side 24 of the base layer 21. Thus, the
inventive index card 20 can be handled and moved across a surface
such as a sheet of paper, a desktop, a countertop, or other like
index cards without adhering thereto via the exposed adhesive 56.
This non-stick feature is also dependent, to some degree, upon the
fact that the cover layer 50 does not sag appreciably (if at all)
into the paperless zone 42 and toward the back side 24 of the base
layer 21, even though it is unsupported across the paperless zone
42 and the edge gap 44 across the upper edge 28 of the base layer
21. In one embodiment, the upper edge 28 of the base layer 21 and
the top edge 60 of the cover layer 50 are co-linear.
[0057] 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
FIGS. 6 and 7, a substrate 70 has a mounting surface 72. The
thickness T of the base layer 21 prevents adherence of the exposed
adhesive 56 in the paperless zone 42 to the mounting surface 72 in
the absence of a threshold level of pressure applied against the
outer face 52 of the cover layer 50 within the area defined by the
paperless zone 42. However, when such a threshold level of pressure
is so applied, the cover layer 50 is sufficiently flexible and
deformable so that at least a portion of the exposed adhesive 56 is
brought into abutting engagement with the mounting surface 72 to
adhere thereto. This relationship is illustrated in FIGS. 6 and 7.
The pressure applied would typically be manual, such as by pressing
against the outer face 52 of the cover layer with a finger or thumb
of a user. This externally applied compressive force would
typically be exerted in a direction substantially normal to the
cover layer 50 and is, of course, to create an adhesion peel force
of adhesive 56 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 cover
layer 50 (e.g., its resiliency), the thickness T of the base layer
21 in the paperless zone 42, the aggressiveness of the adhesive 56
and the nature of the mounting surface 72 of the substrate 70,
among other things. In one embodiment, the threshold level of
pressure refers to the kind of pressure an average user would
normally apply using a finger or hand to adhere a pressure
sensitive adhesive coated film, such as a strip of Scotch.RTM.
brand adhesive tape, to a generally smooth surface such as a sheet
of paper, a wall or a countertop. The target surface does not
necessarily have to be flat. For example, it may be curved such as
a pipe, TV screen or coffee cup.
[0058] 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 FIGS. 4 and 5, thereby again spacing the
adhesive 56 from the back side 24 of the base layer 21. The index
card 20 can then be placed in a stack 80 of note cards 20, such as
illustrated in FIG. 8 (or even shuffled among other like index
cards) without the index cards sticking to each other or to a
horizontal surface 82 upon which the stack 80 may be placed. In
FIG. 8, the index cards 20 have been arranged top to bottom, and
are viewed from the top edges of the index cards 20, thereby
illustrating the paperless zone 42 and edge gap 44 of each index
card 20. When in this orientation, firm pressure applied across the
stack 80 (such as illustrated by pressure P in FIG. 8) would cause
all the index cards 20 in the stack 80 to stick together, with
adjacent cover layers 50 in adherence via exposed adhesive 56.
[0059] 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 FIGS. 6 and 7). Upon release of that
pressure (and peel release of the adhesive 56), the cover layer 50
substantially returns to its undeformed original shape (as seen in
FIGS. 4 and 5). The outer face 52 of the cover layer 50 may also be
a writeable surface. In addition, the outer face 52 of the cover
layer 50 may bear indicia for aesthetics or advertising purposes
(such as graphics which may be pre-printed on the cover layer 50),
or to facilitate visually sorting the index cards 20. In one
embodiment, that indicia includes a color (e.g., the entire outer
face 52 of the cover layer may be coated with a layer of colorant
such as green, blue or red) to make it distinctive relative to the
front side 22 of the base layer 21 (which is typically white).
[0060] 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".
[0061] 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.
[0062] The index card 20 of FIGS. 1-8 illustrates one embodiment of
the present invention. FIGS. 9-17 illustrate alternative
embodiments. In FIG. 9, a note card 120 is constructed with a base
layer 121 otherwise the same as the note card 20, but has a
paperless zone 142 which is smaller in area and shaped differently,
although still presenting an edge gap 144 along an upper edge 128
of the base layer 121. In FIG. 9, the paperless zone 142 is
illustrated as a semicircle or near semicircle, and is viewed from
a back side 124 of the index card 120. A cover layer 150 is
provided on a front side of the index card 120, and a pressure
sensitive adhesive 156 on a back face 154 of the cover layer 150 is
visible through the paperless zone 142. A bottom edge 162 of the
cover layer 150 is illustrated by the dashed lines in FIG. 9.
[0063] FIG. 10 illustrates yet another embodiment of the present
invention, in the form of a note card 220. Other than the
difference in the form of its cover layer 250, the note card 220 is
similar in construction to the note card 120 of FIG. 9. FIG. 10
shows the note card 220, as viewed from the upper edge thereof. The
base layer 221 has a paperless zone 242 thereon, with the cover
layer 250 adhered to a front side 222 of the layer 221 by pressure
sensitive adhesive 256. The cover layer 250 does not extend across
the entire front face 222 of the base layer 221 but only slightly
overlaps the edges of the paperless zone 242 (enough overlap to
facilitate bonding of the cover layer 250 to the base layer 221).
FIG. 11 illustrates the index card 220 with the cover layer 250
deformed to bring the adhesive 256 thereon into adhering engagement
with a mounting substrate surface 272.
[0064] FIG. 12 illustrates yet another form of inventive index card
320, having an alternatively shaped paperless zone 342. Other than
the shape of the paperless zone 342, the index card 320 has the
same attributes as the index cards 20, 120 and 220 disclosed above.
In the index card 320, a base layer 321 has a paperless zone 342
which is V-shaped. As with previous embodiments, however, the
paperless zone has an edge gap 344 exposed along an upper edge 328
of the base layer 321. A cover layer 350 is adhered to a front side
of the base layer 321 by pressure sensitive adhesive 356, with the
adhesive 356 visible (and operable) via the paperless zone 342, as
viewed from a back side 324 of the index card 320 in FIG. 12.
[0065] FIG. 13 illustrates another embodiment of an inventive index
card 420. Other than the form of the paperless portions of the
index card 420, this embodiment has the same attributes as the
index cards 20, 120, 220 and 320 disclosed above. In this
embodiment, a plurality of paperless zones 442 are provided along
an upper edge 428 of a base layer 421 of the index card 420. A
cover layer 450 extends across a front face of the layer 421 such
that pressure sensitive adhesive 456 is exposed across each of the
paperless zones 442.
[0066] 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.
[0067] 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 FIG. 14,
both sides of the index card may be so mounted. The index card 520
illustrated in FIG. 14 has a base layer 521 with a cover layer on
each of its major sides, adjacent top and bottom edges thereof.
FIG. 14 illustrates a front side 522 of the base layer 521 of the
index card 520, with a cover layer 550 adhered thereto, adjacent
upper edge 528. A paperless zone 542 adjacent the upper edge 528 is
illustrated by dashed lines 558 and defines an edge gap 544 across
the upper edge 528. Pressure sensitive adhesive is thus exposed on
a back face of the cover layer 550, across the paperless zone 542.
In addition, a second paperless zone 582 is removed adjacent a
lower edge 530 of the base layer 521. The second paperless zone 582
also defines a second edge gap 584 across the lower edge 530 of the
base layer 521. A second cover layer 590 is formed similar to the
cover layer 550, and has a back face 594 adhered to a back side of
the base layer 521 by pressure sensitive adhesive 596. The adhesive
596 is thus exposed on the front side 522 of the base layer 521,
across the second paperless zone 582. As a result, the index card
550 can be adhered to a substrate surface on either its front side
or its back side. When not adhered, the thickness of the base layer
521 spaces the exposed adhesive on both sides of the index card 520
from adjacent abutting surfaces, thereby allowing the index card to
be freely moved about, stacked or reshuffled. Other than the
addition of an oppositely facing area of exposed adhesive, the
index card 520 of this embodiment has the same attributes as the
index cards 20, 120, 220, 320 and 420 discussed above.
[0068] FIGS. 15-17 illustrate another embodiment of an inventive
index card. In this embodiment, index card 620 has a base layer
621, but the base layer 621 does not necessarily have a paperless
zone or associated cover layer. An area or land 625 is embossed in
the base layer 621 to create a recess 627 on a back side 624
thereof (see FIG. 16). The embossed area 625 may be formed so that
an opposite area on a front side 622 of the base layer 621 has no
surface discontinuities, or it may be formed so that a slightly
raised area 629 is formed on the front side 622.
[0069] 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 (FIG. 17) by the
application of a threshold level of pressure against the front side
622 of the base layer 621, opposite the adhesive 657. The embossed
area 625 of the base layer 621 stretches slightly under this
pressure, illustrated as pressure P in FIG. 17, to bring the
exposed face 659 of the adhesive 657 into abutting engagement and
adherence with the mounting surface 672. The base layer 621 is
flexible enough to allow such stretching and maintain the shape
illustrated in FIG. 17 so that the index card 620 remains adhered
to the substrate 670 (e.g., a wall, countertop, paper sheet, etc.).
The embossed area 625 thus acts as a "pushbutton" for activating
adherence of the index card 620 to the substrate 670. The embossed
area 625 can be formed so that once the index card 620 is peeled
away from the substrate 670, the embossed area 625 returns to its
original recessed position (FIG. 16) or remains pushed out toward
the back side 624 of the base layer 621. In this latter instance, a
user can then "pop" or "snap" the embossed area 625 back to its
original recessed position (FIG. 16) like an on/off switch. The
index card 620, although differing in some construction elements
from the other embodiments disclosed herein, has the same
functional attributes. For example, it can be stacked and shuffled
free without unintended adherence to other cards or surfaces.
[0070] FIGS. 18-20 illustrate another embodiment of an inventive
index card, which is a further modification of the embodiment
illustrated in FIGS. 15-17. In this embodiment, index card 620a has
a base layer 621a. The base layer 621a has an upper edge 628, lower
edge 630, and side edges 632 and 634. An area or land 625a is
provided in the base layer 621a to create a recess 627a on an
otherwise generally planar back side 624a thereof (see FIG. 19A).
Recess 627a may be formed in the base layer 621a by any suitable
process, such as embossing to compress the thickness of the base
layer 621a or by sciving off a layer of the thickness of the base
layer 621a. As illustrated in FIG. 19A, the recess 627a is formed
so that an opposite area on a front side 622a of the base layer
621a has no surface discontinuities corresponding to the recess
627a.
[0071] 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 FIG. 19B) by the
application of a threshold level of pressure against the front side
622a of the base layer 621a, opposite the adhesive 657a. The recess
657a of the base layer 621a stretches slightly under the pressure,
illustrated as pressure P in FIG. 19B, to bring the exposed face
659a of the adhesive 657a into an abutting engagement and adherance
with the mounting surface 672a. The base layer 621a is flexible
enough to allow such stretching and maintain the type of deformed
shape illustrated in FIG. 19B so that the index card 620a remains
adhered to the substrate 670a (e.g. a wall, countertop, paper
sheet, etc.).
[0072] 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 FIG. 20. Thus, pressure
applied (in direction P in FIG. 19B) at one or more locations
across the recess 627a urges the exposed face 659a of the adhesive
657 into an abutting engagement and adherance with the mounting
surface 672a. The recess 627a is formed so that once the index card
620a is peeled away from the substrate 670a, the adhesive 657a
essentially returns to its original recessed position (FIG. 19A).
The index card 620a, although differing in some construction
elements from the other embodiments disclosed herein, has the same
functional attributes. For instance, upon the application of the
threshold level of pressure, the index card 620 can be selectively
adhered to a target surface. Once removed from the target surface,
however, the index card 620a can still be stacked and shuffled
without unintended adherence to other cards or surfaces.
[0073] 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 FIGS. 1-8) or may
be the back side of the base layer itself with a recessed defined
therein, (such as in the embodiments of FIGS. 15-20), or the
standoffs may constitute additional elements or features applied to
the back side of the base layer or formed from the base layer, as
disclosed in the embodiments of FIGS. 21-43.
[0074] 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.
[0075] FIGS. 21 and 22 illustrate another embodiment of the present
invention, as a sheet in the form of a note card or index card 720.
The note index card 720 is defined by a base layer 721 of material
having a front side 722 and an opposite back side 724. The base
layer 721, viewed from the back side 724 in FIG. 21, has an upper
edge 728, a lower edge 730, and side edges 732 and 734.
[0076] 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 FIG. 21, a layer of pressure sensitive adhesive
756 is applied to the back face 724 and extends across the width of
the base layer 721, from side 732 to side 734. The adhesive 756 is
applied in a generally uniform thickness on the back side 724, and
thus has a generally planer exposed surface 759. An upper raised
element 761 is disposed adjacent the upper edge 728 of the base
layer 721. In the embodiment of FIG. 21, the upper raised element
761 is elongated, generally linear, and extends along the upper
edge 728 of the base layer 721. The upper raised element 761 is
adhered to the surface 759 of the adhesive 756, and projects
outwardly therefrom (relative to the back side 724 of the base
layer 721) a standoff distance S.sub.1 (see FIG. 22A) to an upper
standoff surface 763. A lower raised element 765 may be similarly
formed and adhered to the surface 759 of the adhesive 756. The
lower standoff element 765 likewise projects outwardly relative to
the back side 724 of the base layer 721 by a standoff distance
S.sub.2 (see FIG. 22A) to a lower standoff surface 767. In one
embodiment, the standoff distance S.sub.1 is equal to the standoff
distance S.sub.2, but those distances are not necessarily equal. In
other words, the exposed surface 759 of the adhesive has a first
height relative to the back side 724 of the base layer 721, and the
upper and lower standoff surfaces 763 and 767 have greater heights
than the first height.
[0077] The standoff distances S.sub.1 and S.sub.2 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 FIG. 21 as
spacing Z. The non-stick feature of the note card 720 is also
dependent, to some degree, upon the length of spacing Z, the height
of the standoff distances S.sub.1 and S.sub.2, and the stiffness of
the base layer 721 in the area thereof bearing the adhesive 756.
These attributes are designed so that the base layer 721 does not
sag appreciably (if at all) in the recess zone 769 defined for the
adhesive 756 between the raised elements 761 and 765.
[0078] The arrangement disclosed in FIGS. 21 and 22A defines a note
card assembly having a securing mechanism for allowing selective
adherence of the note card 720 to a mounting substrate. As seen in
FIG. 22B, a substrate 770 has a mounting surface 772 is shown. The
standoff distances S.sub.1 and S.sub.2 prevent adherence of the
exposed surface 759 of the adhesive 756 in the recess zone 769 with
the mounting surface 772 in the absence of a threshold level of
pressure applied against the first side 722 of the base layer 721
opposite the adhesive 756. However, when such a threshold level of
pressure is so applied, the base layer 721 is sufficiently flexible
and deformable so that at least a portion of the exposed surface
759 of the adhesive 756 is brought into an abutting engagement with
the mounting surface 772 to adhere thereto. This relationship is
illustrated in FIG. 22B. As noted above, the pressure applied would
typically be manual, such as by pressing against the first side 722
of the base layer 721 with a finger or thumb of a user, in
direction P as shown in FIG. 22B. While the adhesive 756 is
activated to retain the note card 720 in adherence to the substrate
770, the base layer 721 may deform on its first side 722, although
such deformation may not even be visually or tactilally appreciable
to a user. The raised elements 761 and 765 may, under pressure P,
compress slightly, but still retain sufficient height to space the
base layer 721 from the mounting surface 772, as seen in FIG. 22B.
Although two parallel raised elements are shown, in some
embodiments, three or more may be desired.
[0079] In FIG. 22B, the deformed portion of the base layer 721 is
shown as portion 721a, which is deformed or bowed at edge portions
775 adjacent the raised elements 761 and 765 to bring the exposed
surface 759 of the adhesive 756 into adhering engagement with the
mounting surface 772. In this manner, note card 720 may be fixed to
a wall, window or other vertically oriented surface and will be
retained there by the adhesive 756. Thus, one can stick a note card
up for study or memory purposes. Upon removal of the note card 720
from the substrate 770, the deformed base layer 721a reverts to the
base layer 721 form illustrated in FIG. 22A. The adhesive 756 thus
again has its exposed surface 759 spaced from contact with another
surface within the recess zone 769 defined between the raised
elements 761 and 763. The note card 720 can then be placed in a
stack of note cards or shuffled among other like note cards without
the note cards sticking to each other or to a horizontal surface
upon which the stack of note cards may be laid. When a plurality of
such note cards are arranged with their upper edges along the same
side of such a stack, firm pressure applied across the stack (in
like direction to pressure P in FIG. 22B) causes the note cards in
the stack to stick together, with adjacent base layers in adherence
via the exposed adhesive.
[0080] 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 FIGS. 22A,
22B and 23. In the embodiment of FIGS. 22A and 22B, the upper and
lower raised elements are strips of material which are adhered to
the adhesive 756, (such as a strip of paper, polymer, tape, or a
coating of a material such as a varnish coating).
[0081] FIG. 23 illustrates an alternative embodiment for a note
card 720a where an upper raised element 761a and a lower raised
element 765a are not adhered to the adhesive 756, but are bonded
directly to the back side 724 of the base layer 721. The securing
mechanism of the note card 720a illustrated in FIG. 23 functions in
the same manner as described above, since the upper and lower
raised elements 761a and 765a function to define a recess zone 769a
for the adhesive 756 and serve to space and standoff the exposed
surface 759 of the adhesive 756 from a mounting surface or the
surface of an adjacent note card.
[0082] Another example of the formation of upper and lower raised
elements is illustrated in FIG. 24. In this embodiment, a note card
720b has an upper raised element 761b and a lower raised element
765b which are each formed by a bead of material which has been
deposited on the back side 724 of the base layer 721 (the bead may
be deposited over the adhesive 756 or adjacent thereto). The bead
material (which could be formed, for example, from an aqueous based
glue which hardens upon exposure to ambient conditions) has an
outermost standoff surface (its surface spaced farthest from the
back side 724 of the base layer 721) which defines the standoff
distance from the exposed surface 759 of the adhesive 756. The
securing mechanism of the note card 720b functions in the same
manner as described above. The standoff distance for each raised
element 761b and 765b is again a distance sufficient to space the
exposed surface 759 of the adhesive 756 in a reces zone 769b from
another surface contacting the back side 724 of the base layer 721,
in the absence of an application of the threshold level of
pressure.
[0083] In the embodiments illustrated in FIGS. 21-24, the upper and
lower raised elements are shown as continuous strips of material.
In alternative embodiments, the upper and lower raised elements may
discontinuous, such as upper raised element 761c and lower raised
element 765c on a note card 720c, as seen in FIG. 25. The upper and
lower raised elements 761c and 765c can be aligned over the
adhesive 756 or adjacent thereto, and although not continuous, are
aligned in a generally linear and parallel arrangement. The
separated segments of the upper and lower raised elements may be
the same length or differing in length, so long as the raised
elements serve the function of providing the standoff distance
necessary to prevent unattended adhesion of the exposed surface 759
of the adhesive 756 but still provide the "on-demand" adhesive
characteristic for the note card 720c.
[0084] FIG. 26 illustrates alternative discontinuous strips in the
form of a plurality of upper and lower raised elements 761d and
765d, respectively, on a note card 720d. These raised elements are
still, as shown, aligned in a generally linear and parallel
arrangement with the adhesive 759 disposed in a recess zone 769d
(see FIG. 27A) formed therebetween. FIG. 27A illustrates that
elements 761d and 765d may be formed from discreet drops or masses
of bead material deposited on the second side 724 of the base layer
721. Such drops may be deposited in liquid form which then harden
or cure upon exposure to ambient conditions at a height which
provides the requisite standoff distances for both the upper raised
element 761d and lower raised element 765d, relative to the exposed
surface 759 of the adhesive 756, thereby achieving the "on-demand"
adhesive characteristics discussed above for the securing
mechanism.
[0085] Another alternative means for forming a plurality of
discreet standoff elements is illustrated in FIG. 27B. In this
embodiment, upper and lower raised elements 761e and 765e are
formed by arrays of perforations 777 made in a base layer 721e.
Each perforation 777 is made from a front side 722e to a back side
724e of the base layer 721e. Thus, a portion of the base layer 721e
material is deformed and projects outwardly from the back side 724e
to define a peak as the upper raised element 761e or the lower
raised element 765e. The upper and lower raised elements 761e and
765e project sufficiently from the back side 724e of the base layer
721e to provide the requisite standoff distance and resultant
functional advantages of the securing mechanism, as defined above.
A recess zone 769e is effectively defined between the array of
upper raised elements 761e and the array of lower raised elements
765e. Pressure sensitive adhesive 756 is disposed in that recess
zone 769e and the standoff distance provided by the upper and lower
raised elements 761e and 765e separates the exposed surface 759 of
the adhesive 756 from any abutting surface (until application of
the threshold level of pressure, as discussed above). Perforations
777 can be made through the adhesive 756 or alongside the adhesive
756. The perforations can be holes, circles, dash lines or any
geometry which is suitable to provide the requisite standoff
distance.
[0086] 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.
[0087] In a note card 720e of the form shown in FIG. 27B, the
perforations 777 defining the lower raised elements 765e can also
be used to facilitate folding an upper section 779 of the base
layer 721e over as a hinge. When this is done, the adhesive 756 on
the upper section 779 is brought into adhering engagement with the
back side 724e of the base layer 721e below the lower raised
elements 765e. This covers all exposed adhesive, thus eliminating
the possibility of the note cards 720e sticking to the surfaces of
like note cards via the adhesive, and also keeps the adhesive from
becoming contaminated with dirt, paper, fibers, etc. The folded
over, adhesive bearing upper section 779 of the base layer 721e can
later be unfolded to expose the adhesive and again provide
"on-demand" adhesion of the note card 720e to a target surface.
[0088] FIGS. 28 and 29 illustrate another embodiment of a note card
720f having upper and lower raised elements 761f and 765f. In this
embodiment, the raised elements 761f and 765f are formed by score
lines defined in a base layer 721f of the note card 720f. Like the
perforations of FIG. 27B, the scoring is done from a front side
722f of the base layer 721f. A score valley or crease 781 is thus
defined for each score line on the front face 722f of the base
layer 721f. Likewise, a resultant score line projection is formed
on a back side 724f of the base layer 721f, thereby defining the
upper raised element 761f or the lower raised element 765f. The
raised elements 761f and 765f again are formed to provide a
sufficient standoff distance relative to the adhesive 756, and
specifically relative to the exposed surface 759 of the adhesive
756 which is in a recess zone 769f defined between the upper and
lower raised elements 761f and 765f. The upper and lower raised
elements 761f and 765f are thus formed as ribs from the material of
the base layer 721f. Those ribs may constitute a single rib
extending across the note card 720f or a plurality of ribs thereon
(i.e. a discontinuous rib). The use of a score line to form the
lower standoff element 765f also provides, in this embodiment, a
hinge along the lower raised element 765f which can be used to fold
over an upper section 779f of the base layer 721f to adhere the
upper section 779f to the backside 724f of the base layer 721f via
the adhesive 756. Like the embodiment of FIG. 27B, the folded over,
adhesive ring upper section 779f of the base layer 721f can later
be unfolded to expose the adhesive of the securing mechanism and
again provide "on-demand" adhesion of the note card 720f to a
target surface.
[0089] 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 FIGS. 15-20, the back side of the
inventive note card likewise has a recess formed therein so that an
exposed face of the adhesive is spaced from the back side of the
base layer of the index card. In the embodiments illustrated in
FIGS. 21-29, the adhesive may be disposed directly on the back side
of the base layer of the index card, but raised standoff elements
are also provided so that the exposed surface of the adhesive is
lower in height than the height of the standoffs, and thus again
recessed relative to an adjacent surface which the back side of the
card may contact. In each of the above described embodiments, the
adhesive is provided on the index card already in a pre-defined
recess zone which, by one means or another, establishes the
requisite standoff distances to prevent adhesive from unintended
contact with an abutting surface.
[0090] 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 FIGS. 30-34
requires folding of a portion of the note card to create the height
differential on the back side of the note card which serves as the
standoff distance. A sheet in the form of a note card 820 is
defined by a base layer 821 having a front side 822 and an opposite
back side 824. The base layer 821 has an upper edge 828, lower edge
830 and side edges 832 and 834. In this embodiment, adhesive 856 is
disposed in a band adjacent the upper edge 828 of the base layer
821, and extends to a score line 829 (shown in dashed lines), which
is parallel to the upper edge 828 and spaced from it. Below the
score line 829, the back side 824 of the base layer 821 is free of
adhesive. The adhesive 856 is disposed on the back side 824 of the
base layer 821, and extends from side edge 832 across the note card
820 to side edge 834.
[0091] 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 FIG. 30.
[0092] 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 FIG. 31. This folding sequence is illustrated
in FIGS. 32, 33 and 34, where FIG. 32 shows the note card 820 in an
unfolded state, FIG. 33 shows the note card 820 in a partially
folded state, and FIG. 34 shows the note card 820 in a fully folded
state. Once folded as described and shown, an upper non-folded tab
portion 847 constitutes the uppermost part of the note card 820, as
seen in FIG. 31. In this embodiment, the tab portion 847 bears
adhesive 856 thereon. That portion of the band of adhesive 856
which is disposed on the spacing portion 845 (referenced as
adhesive 857) is used to adhere the spacing portion 845 to the back
side 824 of the base layer 821, as seen in FIGS. 31 and 34.
[0093] The thickness of the spacing portion 845 of the base layer
821 thus defines a standoff distance S.sub.3 (see FIG. 34) for
spacing the adhesive 856 on the tab portion 847 from an adjacent
surface. The folded over spacing portion 845, although not
immediately adjacent an exposed surface 859 of the adhesive 856
other than at the first and second ends 833 and 841 of the cut 831,
still provides a sufficient height differential to prevent
unintended contact of the exposed surface 859 with an adjacent
surface such as a mounting surface or adjacent note card surface.
The adhesive is thus effectively "recessed" by means of the
thickness (standoff distance S.sub.3) of the folded over spacing
portion 845. In essence, a front face 823 on the spacing portion
845 becomes its back face when the spacing portion 845 is folded
over, and acts as a standoff surface 825 for the adhesive 856.
[0094] 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 FIGS.
31 and 34), the note card 820 is also then in a configuration where
it may be stacked or shuffled without sticking to other like note
cards or to a substrate surface (at least not without an
application of pressure normal to the plane of the base layer, in
the area of the tab portion 847).
[0095] In this embodiment, when the index card 820 is in its
unfolded state (as illustrated in FIGS. 30 and 32), a plurality of
such index cards may be aligned by their upper edges and then
stacked and adhered together for dispensing purposes (e.g., like a
stack of Post-it.RTM. brand notes such as are available from 3M
Corporation, St. Paul, Minn.). As a note card 820 from such a stack
is desired for use, it may individually be peeled off of the stack,
and if desired, the spacing portion 845 folded over so that the
card assumes the form illustrated in FIG. 31. To facilitate
separation of the adjacent cards, the front side 822 of the base
layer 821 (along with the front face 823 of the attached spacing
portion 845 thereof) may be coated with a slip-enhancing adhesive
release layer (not shown). The shuffleability of the note card 820
once the spacing portion 845 has been folded over to the form seen
in FIG. 31 may be facilitated by the fact that an adhesive release
coating is now disposed on the standoff surface 825 which is
adjacent the exposed surface 859 of the adhesive 856 on the back
side 824 of the base layer 821.
[0096] FIGS. 35-39 illustrate another embodiment of the inventive
note card. In this embodiment, a note card 820a is similar in all
respects to the configuration of the note card 820 in FIG. 30,
except that the location of the band of adhesive is different. In
this embodiment, the band of adhesive 856a begins at its upper edge
along the score line 829 and extends downwardly therefrom to a
lower edge 851 of the adhesive 856a, while still extending across
the note card 820a from the side edge 832 to the side edge 834. The
score line 829 is spaced below the upper edge 828 of the base layer
821. A cut 831 is provided in a similar manner, although the cut
831 is not disposed in this embodiment within the band of adhesive
856a, but above the band of adhesive 856a. The cut 831 begins at a
first end 833 on the score line 829 and extends towards the upper
edge 828 to a first turn 835, and then along a portion 837 which
extends parallel to the upper 828 to a second turn 839. From the
second turn 839, the cut extends to a second end 841 which is on
the score line 829. The first and second ends 833 and 841 of the
cut 831 are spaced apart across the face of the note card 820a.
[0097] 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. FIG. 35
illustrates the note card 820 in an unfolded configuration, while
FIG. 36 illustrates the note card with the spacing portion 845a in
its folded over and adhered configuration. FIGS. 37, 38 and 39
illustrate the sequence of folding over the spacing portion 845a,
relative to the note card 820a.
[0098] Although the band of adhesive 856a is in a different
location in the embodiments of FIGS. 35-39 from the embodiments of
FIGS. 30-34, once the spacing portion 845a of the note card 820a
has been folded over (as shown in FIGS. 36 and 39), it again serves
as the raised standoff element to define a recess zone for an
exposed surface 859a of the adhesive 856a not covered by the
spacing portion 845a. The spacing distance provided thereby is
illustrated in FIG. 39 as spacing distance S.sub.4, which is equal
to the thickness of the spacing portion 845a. In this embodiment,
the exposed surface 859a of the adhesive 856a is bounded on three
sides thereof by portions of the spacing portion 845a, as defined
by the shape of the cut 831. An upper non-folded tab portion 847a
projects at the upper portion of the base layer 821a but does not
bear adhesive thereon, as seen in FIG. 36.
[0099] Once the note card 820a has been placed in its folded over
configuration (FIGS. 36 and 39), the securing mechanism can be
activated by the application of a threshold level of pressure
against the front side 822 of the base layer 821, at one or more
locations opposite the exposed surface 859a of the adhesive 856a.
As in previous embodiments, the base layer 821 is sufficiently
flexible and deformable to permit at least a portion of the exposed
surface 859a of the adhesive 856a to engage an abutting surface and
to adhere to that surface in order to retain the note card 820a in
place. Upon removal of the note card 820a from a mounting surface,
the base layer 821 resumes its undeformed shape (as illustrated in
FIG. 39) and is shuffleable, stackable or may be placed in a
different location and adhered thereto by reapplication of the
threshold level of pressure. In this embodiment, when the index
card 820a is in it's unfold state (as illustrated in FIGS. 35 and
37), a plurality of such index cards may be stacked and adhered
together for dispensing purposes of individual cards. Again,
because the index cards 820A are intended, in a stacked
configuration, to actually be adhered together, a slip-enhancing
adhesive release layer (not shown) may be provided on the front
side 822 of the base layer 821 of each index card 820a to
facilitate separation of adjacent cards from the stack. As noted
above with respect to the embodiment illustrated in FIGS. 30-34,
providing such an adhesive release layer may further enhance
shuffleability of the note cards 820a once the spacing portion 845a
has been folded over, since the standoff surface 825 has an
adhesive release coating thereon.
[0100] Another embodiment of the inventive article of the present
invention as illustrated in FIGS. 40-41. A sheet in the form of a
note card or index card 920 is defined by a base layer 921 of a
material having a front side 922 and an opposite back side 924. The
base layer 921, viewed from the backside 924 in FIG. 40, has an
upper edge 928, a lower edge 930, and side edges 932 and 934.
[0101] 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.
[0102] In the embodiment illustrated in FIG. 40, the spacer layer
911 has an upper edge 912 which extends along the upper edge 928 of
the base layer 924. The spacer layer 911 extends downwardly from
its upper edge 912 toward the adhesive 956 and is formed to define
boundaries for a "recess" zone bounding the adhesive 956 and to act
as a standoff element for the adhesive 956. An edge 913 of the
spacer layer 911 adjacent the adhesive 956 may include one or more
arc shape portions 914 thereon. In this particular embodiment, each
arc shaped portion 914 thus bounds the adhesive on three sides
thereof, thereby effectively recessing an exposed surface 959 of
the adhesive relative to a standoff surface 915 of the spacer layer
911. This relationship is illustrated in FIG. 41, where a standoff
distance S.sub.5 is shown between the exposed surface 959 of the
adhesive 956 and the standoff surface 915 of the spacer layer
911.
[0103] The standoff distance S.sub.5 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 S.sub.5) 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.
[0104] The pattern of a spacer layer or raised element relative to
the exposed surface of the adhesive illustrated by the embodiment
of FIG. 40 is but one example of a suitable pattern or shape for
the inventive pressure activated securing mechanism arrangement.
Other patterns are illustrated by other embodiments described
herein, and additional illustrative patterns are illustrated in
FIGS. 42-43.
[0105] In FIG. 42, a sheet in the form of a note card or index card
1020 is defined by a base layer 1021 having a structure similar to
that of the base layers described above, such as base layer 721 of
FIG. 21. As seen in FIG. 42, the base layer 1021 has a back side
1024, with an upper edge 1028, a lower edge 1030, and side edges
1032 and 1034.
[0106] 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 FIG. 42, each raised
element is shown as a generally linear member extending from the
upper edge 1028 of the base layer 1021 to a lower end adjacent a
lower edge 1051 of the adhesive 1056, and the raised elements 1061
are parallel. The lower edge of each raised element 1061 may stop
short of the lower edge 1051, be co-terminous therewith or extend
beyond it. Each raised element 1061 may be applied over the
adhesive 1051, or directly to the back side 1024 of the base layer
1021, between adjacent zones of adhesive 1056. Each raised element
1061 may be formed from a sheet of material such as paper or
polymer, a separately adhereable tape material, or a coating of
masking material (such as a varnish coating) which is applied over
the back side 1024 of the base layer 1021.
[0107] 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.
[0108] FIG. 43 illustrates yet a further pattern or shape for
defining a securing mechanism which includes a pressure threshold
adhesive mechanism based on user selected activation of exposed
pressure sensitive adhesive. In FIG. 43, a sheet in a form of a
note card or index card 1120 is defined by a base layer 1121. The
base layer is similar in structure to the base layers of previously
disclosed embodiments, such as base layer 721 in FIG. 21. The base
layer 1121 has (as seen in FIG. 43) a back side 1124, an upper edge
1128, a lower edge 1130, and side edges 1132 and 1134.
[0109] 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.
[0110] In the embodiment illustrated in FIG. 43, the raised element
1161 is shown as a serpentine element extending across the back
side 1124 of the base layer 1121, from its first side edge 1132 to
its second side edge 1134. The raised element 1161 is shown as
disposed within the band of adhesive 1156, but may extend at times
beyond an edge of the adhesive 1156, such as beyond a lower edge
1151 thereof. In addition, while the raised element 1161 is shown
having a uniform waveform, it may be nonuniform in wave length and
amplitude. In the illustrative embodiment of FIG. 43, the raised
element 1165 is shown as a mirror image of the raised element 1161,
likewise having a serpentine form, and extending across the back
side 1124 of the base layer 1121, from its side edge 1132 to its
side edge 1134.
[0111] 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.
[0112] While the raised elements shown, for example, in FIGS. 21,
42 and 43, are illustrated as relatively narrow lines, it is
contemplated that raised elements of various widths (such as the
spacer layer 911 in FIG. 40 or spacing portion 845 in FIG. 30) will
suffice. In addition, other patterns for the raised element, such
as a checkerboard or cross-hatch pattern, may suffice.
[0113] 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.
[0114] 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
[0115] 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.times.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 FIGS. 1 and 2. A 0.5 inch wide film adhesive
tape strip is adhered to the front side of the index card adjacent
the upper edge thereof and over the paperless zone and edge gap.
The film and adhesive construction used is the number 811
repositionable tape product available from 3M Corporation, St.
Paul, Minn. The tape strip is formed of acetate, which is about
0.0016 inches thick, and has a coating of microsphere adhesive,
coated to a depth of 0.0004 inches thick. The exposed adhesive on
the back face of the film is recessed by the thickness of the card
stock (0.0075 inches) from the back side of the index card. On a
front face of the film, it is printed with a color coating, for use
in end user sorting of the index cards.
EXAMPLE SET B
Static Angle Test (Sat) for Wall Hang
[0116] 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.degree. 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.
[0117] 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
[0118] 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.degree. 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.
[0119] 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
[0120] The samples in the examples described below were constructed
using Post-it.RTM. Restickable Index Cards, catalog number 6351;
Post-it.RTM. Notes, catalog number 655; and Scotch.RTM. 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.RTM. 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.RTM. Notes samples,
the adhesive stripe is 0.6 inch wide along an upper edge of the
sheet.
[0121] Selectively activated adhesive sheets were produced by
laminating strips of Scotch.RTM. Magic tape to the index cards
samples and the Post-it.RTM. Notes samples to produce standoffs of
varying heights and separation spacings (adhesive stripe width), in
formats similar to the sheet layout shown in FIGS. 21 and 22A. The
tape standoffs were adhered to the paper parallel and on both sides
of the adhesive stripe. In some cases, the tape standoff covered a
portion of the adhesive. Standoffs greater than 0.002 inches in
height were made by stacking layers of the Scotch.RTM. Magic
tape.
EXAMPLES 1-2 AND COMPARATIVE A
[0122] 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. TABLE-US-00001
TABLE 1 Paper Upper Standoff Upper Standoff Space Between Lower
Standoff Lower Standoff Example Thickness, inches Width, inches
Height, inches Standoffs, Inches Width, Inches Height, Inches A
0.0075 NA NA NA NA NA 1 0.0075 0.11 0.006 0.50 0.32 0.006 2 0.0075
0.06 0.002 0.50 0.75 0.002
[0123] TABLE-US-00002 TABLE 2 Distance Lap Shear Test Lap Shear
Test - Static Angle Test - Static Angle Test - Standoff Between
Activated Mode Shuffled Mode Activated Mode, Shuffled Mode, Height,
Standoffs, avg. lbs. avg. lbs. avg. sec. avg. sec. Example inches
inches (std. Deviation) (std. deviation) (std. deviation) (std.
deviation) A NA N/A 5.89 (0.96) 6.17 (1.55) 230 (31.1) 180 (96.5) 2
0.002 0.50 3.75 (0.29) 1.0 (0.28) 101.8 (40.9) 2.75 (0.97) 1 0.006
0.50 3.14 (0.39) 0.48 (0.46) 75.5 (6.7) 0.75 (0.96)
[0124] 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 3-5
[0125] Examples 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.
[0126] 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. TABLE-US-00003 TABLE 3 108 lb Tag stock Paper Top Standoff
Top Standoff Distance Between Bottom Standoff Bottom Standoff
Example Thickness, inches Width, inches Height, inches Standoffs,
Inches Width, Inches Height, Inches 3 0.0075 0.11 0.006 0.25 0.25
0.006 4 0.0075 0.11 0.006 0.50 0.32 0.006 5 0.0075 0.11 0.006 0.75
0.267 0.006
[0127] TABLE-US-00004 TABLE 4 Distance Lap Shear Test- Lap Shear
Test- Static Angle Test - Static Angle Test - Standoff Between
Activated Mode Shuffled Mode Activated Mode, Shuffled Mode, Height,
Standoffs, avg. lbs. avg. lbs. avg. sec. avg. sec. Example inches
inches (std. deviation) (std. deviation) (std. deviation) (std.
deviation) 3 0.006 0.25 0.43 (0.24) 0 (0) 0 (0) 0 (0) 4 0.006 0.50
3.14 (0.39) 0.48 (0.46) 75.5 (6.7) 0.75 (0.96) 5 0.006 0.75 3.13
(0.57) 0.67 (0.45) 169.3 (35.3) 0 (0)
EXAMPLES 6-7 AND COMPARATIVES A AND B
[0128] 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. TABLE-US-00005
TABLE 5 Paper Top Standoff Top Standoff Distance Between Bottom
Standoff Bottom Standoff Example Thickness, inches Width, inches
Height, inches Standoffs, Inches Width, Inches Height, Inches A
0.0075 NA NA NA NA NA 6 0.0075 0.11 0.006 0.75 0.75 0.006 B 0.004
NA NA NA NA NA 7 0.004 0.85 0.006 0.75 0.75 0.006
[0129] TABLE-US-00006 TABLE 6 Lap Shear Test- Lap Shear Test-
Static Angle Test - Static Angle Test - Paper Activated Mode
Shuffled Mode Activated Mode, Shuffled Mode, Thickness, avg. lbs.
avg. lbs. avg. sec. avg. sec. Example inches (std. deviation) (std.
deviation) (std. deviation) (std. deviation) A 0.0075 5.89 (0.96)
6.17 (1.55) 230 (31.1) 180 (96.5) 6 0.0075 3.13 (0.57) 0.67 (0.46)
169.3 (35.3) 0 (0) B 0.004 4.36 (0.26) 4.03 (0.49) 345.7 (62.8) 404
(67.9) 7 0.004 3.78 (1.6) 1.22 (0.22) 351.8 (78.7) 6.25 (10)
[0130] 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.
* * * * *