U.S. patent application number 13/027341 was filed with the patent office on 2011-06-09 for adhesive articles with improved air egress and methods of making the same.
This patent application is currently assigned to AVERY DENNISON CORPORATION. Invention is credited to Michael E. HANNINGTON.
Application Number | 20110132530 13/027341 |
Document ID | / |
Family ID | 35520790 |
Filed Date | 2011-06-09 |
United States Patent
Application |
20110132530 |
Kind Code |
A1 |
HANNINGTON; Michael E. |
June 9, 2011 |
Adhesive Articles with Improved Air Egress and Methods of Making
the Same
Abstract
Methods of making adhesive articles providing air egress by
supplying a route for the air to flow out from under the
construction are described. One method includes providing a release
liner comprising a moldable layer having a release surface and a
back surface; applying a first pattern of a first non-adhesive
material to a first portion of the release surface; applying a
second pattern of a second non-adhesive material to a second
portion of the release surface, wherein the second pattern
partially overlaps the first pattern; embedding at least one of the
first or second non-adhesive materials into the moldable layer; and
transferring an adhesive layer having a front and back surface and
end edges onto the release liner, wherein the front surface of the
adhesive layer is adhered to the release surface of the release
liner.
Inventors: |
HANNINGTON; Michael E.;
(Madison, OH) |
Assignee: |
AVERY DENNISON CORPORATION
Pasadena
CA
|
Family ID: |
35520790 |
Appl. No.: |
13/027341 |
Filed: |
February 15, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10596659 |
Jun 20, 2006 |
7910187 |
|
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PCT/US2005/029544 |
Aug 19, 2005 |
|
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13027341 |
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60606177 |
Aug 31, 2004 |
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Current U.S.
Class: |
156/235 |
Current CPC
Class: |
C09J 7/20 20180101; Y10T
428/2486 20150115; Y10T 428/1471 20150115; Y10T 156/1041 20150115;
Y10T 156/1039 20150115; B29C 63/0047 20130101; C09J 2203/334
20130101; C09J 2301/206 20200801; B32B 9/00 20130101; B29C 63/02
20130101; C09J 7/403 20180101; C09J 2301/204 20200801; Y10T 428/14
20150115; Y10T 428/1476 20150115; Y10T 428/1486 20150115; B32B
37/00 20130101; Y10T 428/24802 20150115; Y10T 428/24479 20150115;
Y10T 156/1089 20150115 |
Class at
Publication: |
156/235 |
International
Class: |
B32B 37/00 20060101
B32B037/00 |
Claims
1. A method of making an adhesive article comprising: (a) providing
a release liner comprising a molding layer having a release surface
and a second surface; (b) applying a first pattern of a first
non-adhesive material to a first portion of the release surface;
(c) applying a second pattern of a second non-adhesive material to
a second portion of the release surface, wherein the second pattern
partially overlaps the first pattern; (d) embedding at least one of
the first or second non-adhesive materials into the molding layer;
and (e) applying an adhesive layer having a first surface and a
second surface onto the release surface of the release liner,
wherein the first surface of the adhesive layer is adhered to the
exposed portions of the non-adhesive materials and to the release
surface of the release liner.
2. The method of claim 1 wherein (f) a facestock is applied to the
second surface of the adhesive layer.
3. The method of claim 2 wherein the embedding comprises applying
heat and pressure to the non-adhesive materials and the release
liner using a roller or platen.
4. The method of claim 1 wherein the second surface of the release
liner is a release surface or a release surface is applied to the
second surface of the release liner.
5. The method of claim 4 further comprising applying a second
adhesive layer to the release surface on the second surface of the
release liner.
6. The method of claim 1 wherein at least one of the first pattern
and the second pattern comprises a plurality of lines wherein at
least about 50% of the liner intersect the end edges of the
adhesive layer.
7. The method of claim 1 wherein the adhesive layer comprises a
pressure sensitive adhesive or a heat-activated adhesive.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a division of U.S. patent
application Ser. No. 10/596,659 filed Jun. 20, 2006, which is a 371
of International Patent Application No. PCT/US2005/29544 filed Aug.
19, 2005, which claims the benefit of U.S. Provisional Application
No. 60/606,177 filed Aug. 31, 2004, all of which are incorporated
herein by reference their entireties.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates generally to adhesive articles having
improved properties such as air egress, repositionability and
slideability, and to methods of making the same. Such articles are
useful in diverse adhesive applications such as, for example,
tapes, labels, industrial graphics applications, articles used for
graphic images, such as those used on vehicles, specialty materials
for signage, and decorative wall coverings.
BACKGROUND OF THE INVENTION
[0003] Pressure sensitive adhesives have enjoyed great acceptance
for their convenience of use. The pressure sensitive adhesive is
often used for tapes and articles containing graphic images. The
advantages of the pressure sensitive adhesives are their strong
bonding and simplicity of application. One drawback of these
products is the initial tenacity of the pressure sensitive
adhesive. The positioning of the product must be precise because of
the initial strong bond of the adhesive. A need exists to make such
products using pressure sensitive adhesives which are
repositionable, i.e. the product may be removed after light
application of pressure without damaging the product or the
substrate. Similarly, a need exists for the products to be able to
slide. Slideability allows for correction of alignment of the
product without the need of completely removing the product and
possibly damaging the adhesive article or substrate.
[0004] When the product is a graphic image and is applied over an
area like a wall or truck panel, there is the possibility of
trapping air under the product and forming bubbles or wrinkles. In
order to avoid such problems, the product should exhibit air
egress, i.e. the product should provide a route for air trapped
under the product to be removed or to escape.
[0005] A need exists for products which have one or more of the
desirable properties of air egress, repositionability and
slideability.
SUMMARY OF THE INVENTION
[0006] This invention relates to an adhesive article which provides
at least one of air egress, repositionability and slideability. Air
egress is provided by supplying at least one route, such as areas
of no initial adhesion or channels in which there is no contact
between the adhesive article and the substrate, for the air to flow
out from under the construction. The repositionability and
slideability are obtained from the presence of areas of no initial
adhesion and/or protrusions of non-adhesive materials from the
adhesive.
[0007] In one embodiment, the invention relates to an adhesive
article including (a) a release liner having a release surface,
molding layer and a second surface; (b) a continuous layer of
adhesive having a first surface, a second surface and end edges,
wherein the first surface of the adhesive is adhered to the release
surface of the release liner; (c) a first pattern of first
non-adhesive material forms having a first surface and a second
surface; and a second pattern of second non-adhesive material forms
having a first surface and a second surface, wherein the second
pattern partially overlaps the first pattern; at least one of the
first and second patterns is embedded into the release surface and
molding layer of the release liner; the first surface of each of
the two patterns is in contact with the adhesive layer; and the
first surface of at least a portion of the first pattern of the
non-adhesive material forms is in a plane that is different from
the plane of the first surface of at least a portion of the second
non-adhesive material forms.
[0008] The invention further relates to methods of preparing the
adhesive articles. One method of making the adhesive articles of
the present invention comprises (a) providing a release liner
comprising a molding layer having a release surface and a second
surface; (b) applying a first pattern of a first non-adhesive
material to a first portion of the release surface; (c) applying a
second pattern of a second non-adhesive material to a second
portion of the release surface wherein the second pattern partially
overlaps the first pattern; (d) embedding at least one of the first
or second non-adhesive materials into the molding layer; and (e)
applying an adhesive layer having a first surface, a second
surface, and end edges onto the release liner, wherein the first
surface of the adhesive layer is adhered to the release surface of
the release liner.
[0009] In yet another embodiment, the present invention relates to
an adhesive article, comprising a release liner comprising a
release surface, a molding layer and a second surface; a continuous
layer of adhesive having a first surface, a second surface and end
edges, wherein the first surface of the adhesive is adhered to the
release surface of the release liner; a first embossed pattern in
the release surface and the molding layer of the release liner; and
second pattern of a non-adhesive material forms, wherein the second
pattern partially overlaps the first embossed pattern and a portion
of the second pattern at least partially fills in portions of the
first embossed pattern, said embossed pattern and the non-adhesive
material forms each having an exposed first surface and a second
surface, wherein the exposed first surface of at least a portion of
the embossed pattern is in a plane that is different from the plane
of the exposed first surface of at least a portion of the second
pattern of non-adhesive materials forms.
DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view depicting a release liner to
which a first pattern of a non-adhesive material has been applied,
in accordance with the present invention.
[0011] FIG. 2 is a perspective view, and FIG. 2' is a
cross-sectional view, both depicting the release liner of FIG. 1
following a step of embedding the non-adhesive material, in
accordance with an embodiment of the present invention.
[0012] FIGS. 3, 3', 3'' and 4-7 are perspective and cross sectional
views depicting steps of a first embodiment of making an adhesive
article including a release liner with a first pattern and a second
pattern of a non-adhesive material on the release surface.
[0013] FIGS. 8, 9, 9', 9'', 9''', 10 and 11 are perspective and
cross sectional views depicting steps of a second embodiment of
making an adhesive article including a release liner with a first
pattern and a second pattern of a non-adhesive material on the
release surface.
[0014] FIGS. 12a, 12b, 13, 14, 14', 14'', 15 and 16 are perspective
and cross sectional views depicting steps of a third embodiment of
making an adhesive article including a release liner with a first
embossed pattern and a second pattern of a non-adhesive material on
the release surface.
[0015] FIG. 17 is a schematic cross-sectional view depicting a
method of embedding a non-adhesive material into a release liner,
in accordance with an embodiment of the present invention.
[0016] FIG. 18 is a schematic cross-sectional view depicting two
embodiments of a textured surface of a roller used, for example, in
embedding a non-adhesive material into a release liner, or for
applying a texture to a release liner, in accordance with an
embodiment of the present invention.
[0017] It should be appreciated that for simplicity and clarity of
illustration, elements shown in the Figures have not necessarily
been drawn to scale. For example, the dimensions of some of the
elements may be exaggerated relative to each other for clarity.
Further, where considered appropriate, reference numerals have been
repeated among the Figures to indicate corresponding elements.
DETAILED DESCRIPTION
[0018] It should be appreciated that the process steps and
structures described below do not form a complete process flow for
manufacturing a complete adhesive article. The present invention
can be practiced in conjunction with techniques currently used in
the art, and only so much of the commonly practiced process steps
are included as are necessary for an understanding of the present
invention.
[0019] As used herein, the term "textured", when used in reference
to a surface feature, means that the surface has a regular or
repeating texture applied to the surface. As used herein, the term
"matte", when used in reference to a surface feature, means that
the surface has a random, roughened surface. These terms are
defined to include surface elements which are formed as a result of
processes applied to the surface beyond, or in addition to, the
processes used to form the surface. In other words, the texture or
the matte condition can be applied in a step separate from the step
of forming the surface per se.
[0020] In one embodiment, the adhesive articles of the invention
comprise a release liner comprising a release surface, a molding
layer and a second surface; a continuous layer of adhesive having a
first surface, a second surface and end edges, wherein the first
surface of the adhesive is adhered to the release surface of the
release liner; a first pattern of first non-adhesive material forms
having a first surface and a second surface; and a second pattern
of second non-adhesive material forms having a first surface and a
second surface, wherein the second pattern partially overlaps the
first pattern; at least one of the first and second patterns is at
least partially embedded in the release surface and molding layer
of the release liner; the first surface of each of the two patterns
is in contact with the release surface of the release liner, the
second surface of each of the two patterns is in contact with the
adhesive layer; and the first surface of at least a portion of the
first pattern of non-adhesive material forms is in a plane that is
different from the plane of the first surface of at least a portion
of the second pattern of non-adhesive material forms.
[0021] In another embodiment, the adhesive articles of the
invention comprise a release liner comprising a release surface, a
molding layer and a second surface; a continuous layer of adhesive
having a first surface, a second surface and end edges, wherein the
first surface of the adhesive is adhered to the release surface of
the release liner; a first embossed pattern in the release surface
and the molding layer, and a second pattern of a non-adhesive
material forms wherein the second pattern partially overlaps the
embossed first pattern and a portion of the second pattern at least
partially fills in portions of the first embossed pattern, said
embossed pattern and the non-adhesive material forms having an
exposed first surface and a second surface, wherein the exposed
first surface at least a portion of the embossed pattern is in a
plane that is different from the plane of the exposed first surface
of at least a portion of the non-adhesive material forms.
[0022] In another embodiment the adhesive articles do not contain a
release liner. In one embodiment, such adhesive articles may be
described as comprising a continuous layer of adhesive having a
first surface, a second surface and end edges, and a first pattern
of first non-adhesive material forms and a second pattern of second
non-adhesive material forms wherein the second pattern partially
overlaps the first pattern; at least one of said first and second
patterns is at least partially embedded in the first surface of the
adhesive layer; each of said first and second patterns has an
exposed first surface and an opposite second surface that is in
contact with the adhesive; the first surface of at least a portion
of the first pattern of non-adhesive forms is in a plane that is
different from the plane of the first surface of at least a portion
of the second pattern of non-adhesive forms; and at least a portion
of the first pattern protrudes from the first surface of the
adhesive layer.
[0023] In another embodiment, the adhesive article of the invention
comprises a continuous layer of adhesive having a first surface and
a second surface, and a first embossed pattern in the first surface
of the adhesive layer, and a second pattern of non-adhesive
material forms, wherein the second pattern at least partially
overlaps the first pattern and is embedded in the first surface of
the adhesive layer; each of said embossed pattern and second
pattern has an exposed first surface wherein the first surface of
at least a portion of the first embossed pattern is in a plane that
is different from the plane of the first surface of at least a
portion of the second pattern of non-adhesive forms.
[0024] One of the features of the present invention is that the
first surface of at least a portion of the first pattern of
non-adhesive material forms present in the adhesive articles is in
a plane that is different from the plane of the first surface of at
least a portion of the second pattern of non-adhesive material
forms as will be discussed in more detail below in relation to the
figures.
[0025] Release liners useful in the adhesive articles and methods
of present invention may be those known in the art which include a
molding layer having a release surface and a second surface. A
molding layer is a layer into which a non-adhesive material, such
as those disclosed herein, may be imbedded by the methods disclosed
herein and which are known in the art. Thus, in one embodiment, the
release liners useful in the invention may comprise a layer of
moldable material having at least one surface that inherently has
release properties. For example, a layer of low density
polyethylene having release characteristics can be used as the
release liner in the adhesive articles and methods of the
invention.
[0026] Alternatively, when the molding layer does not inherently
have sufficient release characteristics, one or more surfaces of
the molding layer can be coated with a release composition. Release
compositions are known in the art and such compositions include a
variety of silicone compositions. In yet another embodiment, the
release liners useful herein comprise a substrate or base layer
having a molding layer on one side, and a release coating covering
the molding layer. The molding layer may be a polyolefin such as
polyethylene and polypropylene. Examples of such release liners
include polyethylene coated papers with a commercial silicone
release coating and polyethylene coated polyethylene terephthalate
films with a commercial silicone release coating. In one
embodiment, the release liner is kraft paper which has a coating of
low density polyethylene on the front side with a silicone release
coating on the polyethylene, and a coating of high density
polyethylene on the back side. Other release liners known in the
art are also suitable as long as they contain a molding layer and
are selected for their release characteristics relative to the
adhesive chosen for use in the present invention. In one embodiment
of the invention, the release liner has a molding layer of polymer
under the release coating, which softens upon the application of
heat, allowing the non-adhesive material to be embedded into the
molding layer of the release liner. Embedding the non-adhesive
material into the release liner maintains the three-dimensional
stability of the printed pattern and protects the pattern during
handling, storage and transport of the adhesive article.
[0027] The release surface of the release liner may have a textured
finish, a matte finish, a smooth finish, or a patterned finish. The
release layer may have a randomly microstructured surface such as a
matte finish, or have a pattern of three-dimensional
microstructures. The microstructures may have a cross-section which
is made up of circles, ovals, diamonds, squares, rectangles,
triangles, polygons, lines or irregular shapes, when the
cross-section is taken parallel to the surface of the release
surface. The release liner may also have randomly distributed
non-adhesive particulate material applied to the surface of the
release surface. The non-adhesive particulate is then embedded into
the release liner along with the patterned non-adhesive
material.
[0028] In one embodiment, the release liner useful in the adhesive
articles and method of the invention has a release coating on both
sides; and in another embodiment, one side has a release coating of
a higher release value than the release coating of the other
side.
[0029] The adhesive articles of the invention also comprise a
continuous adhesive layer which may comprise a pressure sensitive
adhesive and/or a heat activated adhesive. The adhesive layer
typically has a thickness from about 10 .mu.m to about 125 .mu.m,
or from about 25 .mu.m to about 75 .mu.m, or from about 10 .mu.m to
about 50 .mu.m. In one embodiment, the coat weight of the pressure
sensitive adhesive is in the range of about 10 to about 50 grams
per square meter (gsm), and in one embodiment about 20 to about 35
gsm.
[0030] In one embodiment, the first surface of the adhesive layer
of the articles has a Sheffield roughness of at least about 10 or
at least about 75, or at least about 150. The adhesive layer may
itself have the roughness or may be formed when the adhesive is
coated onto a release liner. It is understood that the release
liner may have a Sheffield roughness at least about 10 or at least
about 50, or at least about 75 or at least about 150. The adhesive
will replicate the complementary texture or pattern of the release
liner. Alternatively, the surface of the release liner can be
rougher depending on the desired configuration of the adhesive
article. The Sheffield roughness is determined by TAPPI T 538
om-88.
[0031] The pressure-sensitive adhesives can be any of the pressure
sensitive adhesives known in the art. These include rubber based
adhesives, acrylic adhesives, vinyl ether adhesives, silicone
adhesives, and mixtures of two or more thereof. Included are the
pressure sensitive adhesive materials described in "Adhesion and
Bonding", Encyclopedia of Polymer Science and Engineering, Vol. 1,
pages 476-546, Interscience Publishers, 2nd Ed. 1985, the
disclosure of which is hereby incorporated by reference. The
pressure sensitive adhesive materials that are useful may contain
as a major constituent an adhesive polymer such as acrylic type
polymers, block copolymers, natural, reclaimed or styrene butadiene
rubbers, tackified natural or synthetic rubbers, random copolymers
of ethylene and vinyl acetate, ethylene-vinyl-acrylic terpolymers,
polyisobutylene, poly(vinyl ether), etc. The pressure sensitive
adhesive materials are typically characterized by glass transition
temperatures in the range of about -70.degree. C. to about
10.degree. C.
[0032] Other materials may be included in the pressure sensitive
adhesive materials. These include solid tackifying resins, liquid
tackifiers (often referred to as plasticizers), antioxidants,
fillers, pigments, waxes, etc. The adhesive materials may contain a
blend of solid tackifying resins and liquid tackifying resins (or
liquid plasticizers). Particularly useful adhesives are described
in U.S. Pat. Nos. 5,192,612 and 5,346,766 which are incorporated
herein by reference.
[0033] The layer of pressure sensitive adhesive can be applied
using standard coating techniques, such as transfer coating,
curtain coating, gravure coating, reverse gravure coating, offset
gravure coating, roller coating, brushing, knife-over roll coating,
air knife coating metering rod coating, reverse roll coating,
doctor knife coating, dipping, die coating, spraying, and the like.
The application of these coating techniques is well known in the
industry and can effectively be implemented by one skilled in the
art. The knowledge and expertise of the manufacturing facility
applying the coating determine the preferred method. Further
information on coating methods can be found in "Modern Coating and
Drying Technology", by Edward Cohen and Edgar Gutoff, VCH
Publishers, Inc., 1992. Alternatively, an adhesive layer can be
applied by transfer of an adhesive layer on a release liner by
procedures known to those skilled in the art.
[0034] The non-adhesive materials of the at least two patterns may
be the same or different. In one embodiment, the non-adhesive
material includes non-adhesive polymers, including ink
compositions, applied by printing methods. In another embodiment,
the non-adhesive material e.g., a metal or metallic or
metal-containing material is applied by vacuum metallization or by
sputtering. The non-adhesive material, after drying, cooling,
and/or curing, releasably adheres to the release surface of the
release liner. In one embodiment, the non-adhesive composition used
to form the patterns contains greater than 50%, or greater than
75%, or greater than 85% solids. In another embodiment, the
non-adhesive composition is 100% solids. Here and elsewhere in the
specification and claims, the limits of the ranges and ratios may
be combined.
[0035] In one embodiment, the non-adhesive material can be any
material that can be used as the ink on a printing machine,
provided that upon drying, cooling, and/or curing, the non-adhesive
material is not tacky. The non-adhesive material may be made of
organic polymeric material such as polyurethane, polyvinyl
chloride, acrylic polymers, acetate, polyethylene, polypropylene or
polystyrene and the like.
[0036] In one embodiment, the non-adhesive composition is a UV
curable ink. The ultraviolet radiation curable inks useful in the
invention generally comprise a binder which comprises one or more
photopolymerizable monomers. The photopolymerizable monomers
generally are ethylenically unsaturated compounds. The unsaturated
compounds may contain one or more olefinic double bonds, and they
may be low molecular weight compounds, (monomeric) or high
molecular weight compounds (oligomeric). Illustrative examples of
monomers containing one double bond are acrylates such as
alkyl(meth)acrylates or hydroxyalkyl(meth)acrylates such as
methyl-, ethyl-, butyl-, 2-ethylhexyl- or 2-hydroxyethylacrylate,
isobornylacrylate, methyl- or ethylmethacrylate. Further examples
of photopolymerizable monomers are acrylonitrile, acrylamide,
methacrylamide, NBsubstituted (meth) acrylamides, vinyl esters such
as vinyl acetate, vinyl ethers such as isobutylvinyl ether,
styrene, alkylstyrenes and halostyrenes, NBvinylpyrrolidone, vinyl
chloride or vinylidene chloride.
[0037] Monomers containing a plurality of double bonds are
typically the diacrylates of ethylene glycol, 1,3-propylene glycol,
1,4-butanediol, 1,4-cyclohexane diol, neopentyl glycol,
hexamethylene glycol, or bisphenol A polyacrylates such as
trimethylolpropane triacrylate and pentaerythritol triacrylate or
tetraacrylate, vinyl acrylate, divinyl benzene, divinyl succinate,
diallyl phthalate, triallylphosphate, triallylisocyanurate or
tris(2-acryloyloxy)ethyl-isocyanurate.
[0038] Typical examples of high molecular weight (oligomeric)
polyunsaturated compounds are acrylated epoxy resins, acrylated
polyethers, acrylated polyurethanes or acrylated polyesters.
Further examples of unsaturated oligomers are unsaturated polyester
resins which are normally prepared from maleic acid, phthalic acid
and one or more diols and which have molecular weights of about 500
to about 3000. Such unsaturated oligomers may also be referred to
as prepolymers. Single component systems based on photocurable
prepolymers are often used as binders for printing inks.
Unsaturated polyester resins are normally used in two-component
systems together with a monounsaturated monomer such as described
above, preferably with styrene.
[0039] The unsaturated compounds also can be used in admixture with
non-photopolymerizable film-forming components. These components
may typically be drying polymers or their solutions in organic
solvents, such as nitrocellulose. They may also, however, be
chemically curable or thermocurable resins such as polyisocyanates,
polyepoxides or melamine resins. The concomitant use of
thermocurable resins is important for use in so-called hybrid
systems which are photopolymerized in a first step and crosslinked
by a thermal after treatment in a second step.
[0040] The UV radiation curable inks also should contain at least
one photoinitiator. A wide range of different photoinitiators is at
present available for UV radiation curable systems. They include
benzophenone and benzophenone derivatives, benzoin ethers, benzil
ketals, dialkoxyacetophenones, hydroxyacetophenones,
aminoacetophenones, haloacetophenones or acryloxyphosphine oxides.
They differ in that they have different absorption maxima. To cover
a wide absorption range it is possible to use a mixture of two or
more photoinitiators. The total amount of photoinitiator in the UV
radiation curable compositions may be in the range of from about
0.05 to about 7, or 10% by weight of the total composition.
Preferably the compositions contain from about 0.2% to about 5% by
weight of the photoinitiator.
[0041] Amines may be added to accelerate the photopolymerization,
for example triethanolamine, N-methyl-diethanolamine,
p-dimethylaminobenzoate or Michler's ketone. The
photopolymerization can further be accelerated by the addition of
photosensitizers which displace or broaden the spectral
sensitivity. These photosensitizers are preferably aromatic
carbonyl compounds such as thioxanthone, anthraquinone and
3-acyl-coumarin derivatives as well as
3-(aroylmethylene)-thiazolines.
[0042] Hindered amine light stabilizers (HALS) which function as
co-stabilizers, also may be added to the UV radiation curable
printing compositions used in the present invention. Examples of
hindered amine light stabilizers include those listed and recited
in U.S. Pat. Nos. 5,112,890 and 4,636,408, which are incorporated
herein by reference. A specific example of a hinder amine light
stabilizer useful in the printing inks is TINUVIN.RTM. 292 which is
identified as bis(1,2,2,6,6-pentamethyl-4-piperidinyl)
sebacate.
[0043] In addition to the above described binder materials and
photoinitiators, the UV radiation curable inks used in the present
invention may also contain coloring matter selected from organic
pigments, inorganic pigments, body pigments and dyes which are
known and have been used in this art. Examples of useful pigments
include titanium dioxide, cadmium yellow, cadmium red, cadmium
maroon, black iron oxide, carbon black, chrome green, gold, silver,
aluminum and copper. Examples of dyes include alizarine red,
Prussian blue, auramin naphthol, malachite green, etc. Generally
the concentration of the pigment or dye in the ink will be from
about 0 to about 70% by weight, and in one embodiment, from about
0.1% to about 50% by weight.
[0044] In addition to the above described coloring matter, the UV
radiation curable inks used in the present invention may also
contain fillers, extenders, surfactants, and the like which are
known and have been used in this art. Examples of useful fillers
and extenders include silicon dioxide, fumed silica, glass or
ceramic microspheres, and glass or ceramic bubbles. Generally the
concentration of the filler or extender will be from about 0 to
about 70% by weight, and in one embodiment, from about 0.5% to
about 50% by weight.
[0045] The printing inks may also contain at least one UV absorber
which provides weathering protection and helps prevent
microcracking. The amount of UV absorber included in the UV
radiation curable ink should be maintained at a practical minimum
since the presence of the UV absorber may increase the curing rate.
A variety of UV absorbers are known and useful in the present
invention and these include UV absorbers belonging to the group of
photopolymerizable hydroxybenzophenones and photopolymerizable
benzotriazoles. U.S. Pat. No. 5,369,140 describes a class of
2-hydroxyphenyl-s-triazines that are useful as UV absorbers for
radiation curable systems. The triazines are effective for
stabilizing cured films when exposed to sunlight over a long period
of time, and these stabilizers do not interfere with UV radiation
curing of the inks. The triazine UV absorbers are effective in
amounts of from about 0.1 to about 2% by weight. The UV absorbers
may be used in combination with other light stabilizers such as
sterically hindered amines. The disclosure of the '140 patent is
hereby incorporated by reference for its disclosure of such UV
absorber combinations. U.S. Pat. Nos. 5,559,163 and 5,162,390 also
describe UV absorbers which are useful in the inks of the present
invention.
[0046] Examples of useful UV curable inks include those available
from Decochem under the trade designation Poly-Rad plastics, as
well as UV curable inks commercially available from Acheson and Dow
Chemical Company.
[0047] In one embodiment of the invention, the ink used to form the
non-adhesive patterns on the release liner is a coalescing ink. The
ink does not efficiently wet out on the surface of the release
liner, but coalesces into smaller areas of ink with an increase in
height. Thus, depending on the degree of coalescence, a line of
printed ink can form a narrower line, or a line made up of what
appear to be random small beads of ink, or a combination, all with
an increase in height. The narrower line, small beads, or
combination are then embedded into the release liner. The thickness
of the ink applied to the surface of the release liner can also
affect the degree of coalescence. Surfactants may be added to the
ink composition to control the degree of coalescence as well.
[0048] In one embodiment of the invention, the ink used to form the
non-adhesive patterns comprises a porous non-adhesive. The porous
non-adhesive may have elastomeric properties, so that if it is
compressed, it essentially returns to its original shape. For
example the porous non-adhesive comprises an ink containing a
blowing agent that causes the ink to expand, forming an open or
closed cell, or combination thereof. The blowing agent is
activated, for example, by the application of heat to the ink.
Other examples of porous non-adhesives include suspensions of gas
and/or particles in a binder.
[0049] Substances which can be deposited by the sputtering or
metallization processes also can be used to form the non-adhesive
patterns in the adhesive articles of the invention. Examples of
such metals include: aluminum, silver, gold, chrome, copper and
nickel.
[0050] As noted, in one embodiment, the adhesive articles of the
present invention comprise a first pattern of a first non-adhesive
material forms and a second pattern of a second non-adhesive
material forms. The present invention may include additional
patterns of non-adhesive material. The present invention may
further include additional non-adhesive materials randomly
distributed, i.e., in no regular pattern. The non-adhesive
materials of the two or more patterns may be the same or different.
The patterns, independently, can be a plurality of dots, lines or
bars, continuous or broken, etc. provided one partially overlaps
the other pattern. In one embodiment, when lines are used, at least
about 50% of the lines extend and intersect the end to edges of the
adhesive layer to provide improved air egress. The lines may vary
in size provided that air egress is maintained. The lines and other
patterns generally have an average thickness from about 0.3 microns
(.mu.m) to about 100 .mu.m, or from about 0.5 .mu.m to about 50
.mu.m, or from about 3 .mu.m to about 30 .mu.m. The width of the
lines may also vary widely. An example of a useful range for line
width is from about 12 .mu.m to about 250 .mu.m, or from about 25
.mu.m to about 125 .mu.m, or from about 50 .mu.m to about 75 .mu.m.
The pattern may be a grid of intersecting lines, a weave pattern, a
waffle pattern, diagonal straight and curved lines, tiled geometric
figures, such as hexagons, rectangles, overlapping circles or
triangles, or lines in a cross hatch pattern. In addition to the
patterns that may be used such as a grid of intersecting lines,
dots and other random shapes may be embedded in the molding layer
of release liner to increase desirable properties such as air
egress, repositionability and slideability.
[0051] In one embodiment, the non-adhesive material is an ink
comprising a UV curable polymer composition, such as a UV curable
acrylic or polyurethane composition. After application, the ink is
cured by irradiation in a UV exposure apparatus as is well known to
those skilled in the art of printing and UV curing. UV light
sources such as low pressure mercury lamps, high pressure mercury
lamps, xenon lamps, arc lamps and gallium lamps are useful. It is
also possible, but not necessary, to improve the curability of the
ink by heating after irradiation.
[0052] In one embodiment, the non-adhesive material is a polymer
composition which is able to be printed by any suitable printing
technique such as screen printing, roller coat printing,
flexographic printing, lithographic printing, gravure printing,
laser printing, ink jet printing, brushing, spraying, dipping or
coating. The type of printing may be any type which can print on
the release liner. One particularly useful printing method is a
modification of flexographic printing which provides both the
printing and embedding of the non-adhesive material.
[0053] The non-adhesive material may also be applied to the release
liner by means of patterned vacuum metallization or sputtering. In
this embodiment, the non-adhesive layer typically has a thickness
from about 30 nanometers (nm) to about 3000 nm, from about 100 nm
to about 2000 nm, or from about 300 nm to about 1500 nm.
[0054] As described above, the adhesive articles may optionally
comprise a facestock. In one embodiment, a facestock may be applied
to the second surface of the adhesive layer which has already been
releasably adhered to a release liner. Alternatively, a combination
of a facestock and an adhesive may be applied to the release liner.
The facestock may be any of those which are useful for decorative
or graphic image applications. The facestocks typically have a
thickness from about 10 .mu.m to about 300 .mu.m, or from about 25
.mu.m to about 125 .mu.m. The facestocks include paper, polyolefins
(linear or branched), polyamides, polystyrenes, nylon, polyesters,
polyester copolymers, polyurethanes, polysulfones,
polyvinylchloride, styrene-maleic anhydride copolymers,
styrene-acrylonitrile copolymers, ionomers based on sodium or zinc
salts of ethylene methacrylic acid, polymethyl methacrylates,
cellulosics, fluoroplastics, acrylic polymers and copolymers,
polycarbonates, polyacrylonitriles, and ethylene-vinyl acetate
copolymers. Included in this group are acrylates such as ethylene
methacrylic acid, ethylene methyl acrylate, ethylene acrylic acid
and ethylene ethyl acrylate. Also, included in this group are
polymers and copolymers of olefin monomers having, for example, 2
to about 12 carbon atoms, and in one embodiment 2 to about 8 carbon
atoms. These include the polymers of alpha-olefins having from 2 to
about 4 carbon atoms per molecule. These include polyethylene,
polypropylene, poly-1-butene, etc. An example of a copolymer within
the above definition is a copolymer of ethylene with 1-butene
having from about 1 to about 10 weight percent of the 1-butene
comonomer incorporated into the copolymer molecule. The
polyethylenes that are useful have various densities including low,
medium and high density ranges. The low density range is from about
0.910 to about 0.925 g/cm.sup.3; the medium density range is from
about 0.925 to about 0.940 g/cm.sup.3; and the high density range
is from about 0.94 to about 0.965 g/cm.sup.3. Films prepared from
blends of copolymers or blends of copolymers with homopolymers also
are useful. he films may be extruded as a monolayer film or a
multi-layered film.
[0055] In one embodiment, the facestock is a polymeric facestock,
which contains migratory additives. The facestocks are preferably
polyvinylchloride facestocks. The additives include plasticizers
and antioxidants. The plasticizer is a high-boiling solvent or
softening agent, usually liquid. It is an ester made from an
anhydride or acid and a suitable alcohol that usually has between 6
to 13 carbon atoms. The plasticizers may be adipate, phosphate,
benzoate or phthalate esters, polyalkylene oxides, sulfonamides,
etc. The plasticizers include but are not limited to DOA
plasticizer (dioctyl adipate), TEG-EH plasticizer (triethylene
glycol di-2-ethylhexanoate), TOM plasticizer (trioctyl
trimellitate), triacetin plasticizer (glyceryl triacetate), TRIB.
plasticizer (2,2,4-trimethyl-1,3-pentanediol diisobutyrate), DEP
plasticizer (diethyl phthalate), DOTP plasticizer (dioctyl
terephthalate), DMP plasticizer (dimethyl phthalate), DOP
plasticizer (dioctyl phthalate), DBP plasticizer (dibutyl
phthalate), polyethylene oxide, toluenesulfonamide, dipropylene
glycol benzoate, and the like.
[0056] In one embodiment, the adhesive articles of the invention
may be prepared by
[0057] (a) providing a release liner comprising a molding layer
having a release surface and a second surface;
[0058] (b) applying a first pattern of a first non-adhesive
material to a first portion of the release surface;
[0059] (c) applying a second pattern of a second non-adhesive
material to a second portion of the release surface, wherein the
second pattern partially overlaps the first pattern;
[0060] (d) embedding at least one of the first or second
non-adhesive materials into the molding layer; and
[0061] (e) applying an adhesive layer having a first surface and a
second surface onto the release liner, wherein the first surface of
the adhesive layer is adhered to the exposed portions of the
non-adhesive materials and to the release surface of the release
liner.
[0062] After the adhesive layer is applied, the release liner may
be removed to provide adhesive articles of other embodiments of the
invention as described herein.
[0063] In another embodiment, (hereinafter sometimes referred to as
the "first embodiment"), only the first pattern of non-adhesive
material is embedded into the molding layer, i.e., the first
pattern of non-adhesive materials forms is embedded in the molding
layer before the second pattern of non-adhesive material forms is
applied to the release liner. Thus, the process of the first
embodiment comprises
[0064] (a) providing a release liner comprising a molding layer
having a release surface and a second surface;
[0065] (b) applying a first pattern of a first non-adhesive
material to a first portion of the release surface;
[0066] (c) embedding the first pattern of a first non-adhesive
material into the molding layer,
[0067] (d) applying a second pattern of a second non-adhesive
material to a second portion of the release surface wherein the
second pattern partially overlaps the first pattern, and
[0068] (e) applying an adhesive layer having a first surface and a
second surface onto the release liner, wherein the first surface of
the adhesive layer is adhered to the exposed portions of the
non-adhesive materials and to the release surface of the release
liner.
[0069] FIGS. 1, 2, 2', 3, 3', 3'' and 4-7 are perspective and cross
sectional views depicting a process of a first embodiment of making
an adhesive article of the invention. FIG. 1 is a perspective view
of a release liner 100 containing a first pattern 106 having an
upper or second surface 106a and a lower or first surface 106b
which is in contact with the release surface 102. The release liner
100 includes a release surface 102, molding layer 104 and substrate
101. A first pattern 106 of a first non-adhesive material has been
applied to the release surface 102. In the embodiment shown in FIG.
1, the first pattern 106 has been applied in a direction
substantially parallel with the sides of the release liner, as
represented by the arrow 108. It should be understood that the
first pattern 106 in this and other embodiments described herein
and illustrated in the figures, may be applied at an angle, such as
about 22.5.degree., about 30.degree., about 45.degree., about
60.degree., about 75.degree., about 90.degree. or about any other
selected angle relative to the direction defined by the arrow 108.
Thus, overlapping patterns may form shapes such as squares or
diamonds when the release liner is viewed in a plan view. In
combination with the angles relative to the direction indicated by
arrow 108 at which the first pattern 106 is applied, both patterns
may be applied at any selected angle with the exception of a
parallel, exactly overlapping identical pattern, in which case, the
effect would be to deposit only one pattern. The release liner 100
may be any suitable release liner having a molding layer 104 into
which a pattern of non-adhesive material, such as the pattern 106,
may be embedded, as described below.
[0070] Following application of the first pattern 106, the first
pattern 106 is embedded into the release surface 102 and molding
layer 104 as shown in FIG. 2. Suitable methods for embedding are
described below.
[0071] FIG. 2 is a perspective view of the release liner 100, after
the first pattern 106 of the first non-adhesive material has been
embedded into the release surface 102 and the molding layer 104.
FIG. 2' is a cross-sectional view taken at line 2'-2' of FIG. 2. In
the embodiment shown in FIGS. 2 and 2', the first pattern 106 is
embedded into the molding layer 104 to a level such that the second
surface 106a of the first pattern 106 (hereinafter generally
referred to as the second surface 106a of the first pattern 106) is
substantially coplanar with the upper surface of the release liner
100. That is the second surface 106a of the first pattern 106 is
substantially coplanar with a plane 102a defined by the release
surface 102 (see FIG. 2'). In other embodiments (not shown), the
first pattern 106 may be embedded to a depth whereby the second
surface 106a of the first pattern 106 is either above or below the
plane defined by the release surface 102. In these latter
embodiments, the first pattern 106 either is only partially
embedded, in which a portion of the first pattern 106 extends above
the plane 102a, or is over-embedded, in which the second surface of
the first pattern 106 is below the plane 102a.
[0072] FIGS. 3, 3' and 3'' depict the release liner 100 after a
second pattern 110 of a second non-adhesive material is applied
onto the release surface 102 of the release liner 100 and at least
a portion of the second pattern 110 overlaps the first pattern 106.
One surface of the pattern 110 (first surface) identified as 110b,
is in contact with the release surface 102 and the first surface
106a of the first pattern 106, and the opposite surface (second
surface) 110a of pattern 110 is exposed. FIG. 3' is a
cross-sectional view taken at line 3'-3' of FIG. 3, and FIG. 3'' is
a cross-sectional view taken at line 3''-3'' of FIG. 3. As shown in
FIGS. 3' and 3'', a plane 102a is defined by the release surface
102. This plane 102a is referred to herein in defining the degree
to which the respective non-adhesive materials are embedded into
the release liner 100. In this embodiment, the second pattern 110
is not embedded into the release liner 100, although in other
embodiments it could be fully or partially embedded (see below). As
depicted in FIG. 3', a first portion of the second pattern is
applied onto the release surface 102 of the release liner 100, and
a second portion is applied onto the upper surface of the embedded
first pattern 106 where the patterns overlap. In this embodiment,
in which the upper or second surface 106a of the embedded first
pattern 106 is substantially coplanar with the plane 102a defined
by the release surface 102, the second pattern 110 forms a strip
having a substantially straight, flat bottom or first surface 110b.
In FIGS. 3, 3' and 3'' the first surfaces 106b of the pattern 106
embedded in the molding layer 104 define a second plane 102b which
is illustrated in these figures as substantially parallel to plane
102a. Alternatively, the plane 102b may not be parallel to plane
102a and for the first surfaces 106b may form more than one plane
which are different from plane 102a.
[0073] In embodiments in which the embedded first pattern 106
extends below or above the plane 102a defined by the release
surface 102 (not shown), the second pattern 110 may be formed
having a stepped appearance (see FIG. 8, which has such a stepped
appearance). In other embodiments, the upper surface of the second
pattern 110 may be substantially straight and flat as shown in
FIGS. 3' and 3'', forming a single plane parallel to the plane
102a, without sagging into or forming a stepped ridge over the
portion of the embedded first pattern 106 which is below the plane
102a.
[0074] FIG. 3'' is a cross-sectional view taken at line 3''-3'' of
FIG. 3. The first pattern 106 appears as a continuous structure,
the upper or second surface 106a of which is coplanar with the
plane 102a defined by the release surface 102, and the first
surfaces 106b define a second plane 102b as described above. The
three illustrated lines of the second pattern 110 in FIG. 3 appear
as three separate structures above the plane 102a.
[0075] Following application of the second pattern 110, an adhesive
layer 112 is applied onto the release surface of release liner 100,
thus forming an adhesive article 114 illustrated in FIG. 4. The
adhesive layer 112 includes a first surface 112c (facing downward,
not shown in FIG. 4), a second surface 112a and end edges 112b. The
first surface of the adhesive layer is adhered to the release
surface 102 of the release liner 100 and to the exposed second
surfaces of the two patterns. The second surface 112a is exposed on
the upper surface of the adhesive article 114 shown in FIG. 4.
[0076] In one embodiment, shown in FIG. 5, a facestock 116 is
applied to the second surface 112a of the adhesive article 114 to
form adhesive article 114a. The facestock 116 may be any of the
facestocks described above including paper or a polymeric film such
as a vinyl (PVC) or polyester film. The facestock 116 is selected
for the desired properties needed by the adhesive article 114a. For
instance, if the adhesive article 114a is to be applied to a
vehicle, then a vinyl facestock is generally selected for its
flexibility and durability. A polyurethane facestock may also be
used for applications which are exposed to weathering. The
facestock 116, although shown in FIG. 5 as a single layer, can
comprise multiple layers with the layers selected for
weatherability, printability, etc. The facestock 116 is in adhesive
contact with the adhesive layer 112, which may be, for example, a
pressure-sensitive adhesive. The adhesive 112 is in adhesive
contact with the release surface 102 and the exposed second
surfaces of the non-adhesive materials of the first pattern 106 and
the second pattern 110. As can be seen in FIG. 5, the second
pattern 110 is embedded into the adhesive layer. When the release
liner 100 is removed from adhesive article 114a, the non-adhesive
material of the first pattern 106 and the second pattern 110 remain
adhered to the adhesive layer 112. It is understood that one or
more of the non-adhesive materials may extend partially into the
adhesive layer but a portion, in one embodiment a major portion, of
at least one of the non-adhesive materials (pattern 106) extends
beyond or protrudes from the surface of the adhesive layer.
[0077] In another embodiment, shown in FIG. 6, the adhesive article
114b includes a second release liner 118, instead of the facestock
116 shown in FIG. 5, applied to the second surface 112a of the
adhesive layer 112. The release liner 118 may be a release-treated
paper or polymeric film such as a vinyl (PVC) or polyester film. In
other embodiments, the release liner 118 may be the same as any of
the materials disclosed herein for use as a release liner such as
for the release liner 100. In the embodiment shown in FIG. 6, when
both release liners 100 and 118 are removed, a double-sided
adhesive article is provided.
[0078] In one embodiment, the release liner 100 may have a texture
formed on its release surface 102. The release liner is thereby a
textured-finish release liner, as defined herein. The textured
surface may be patterned, or the textured surface may have a matte
finish. In one embodiment, the matte finish is a substantially
random pattern. This texture may be imparted to the adhesive and
non-adhesive materials using the textured-finish release liner.
[0079] Other embodiments of adhesive articles and methods of the
invention may be obtained by adding, singly or in combination,
additional layers of non-adhesive forms, adhesive, release
coatings, release liners, and facestocks. A few of the many
examples of such adhesive article constructions are described
herein.
[0080] The release liners used in the methods and adhesive articles
of the invention can have molding and release layers on both the
first and second surfaces of a base or carrier layer allowing for
the fabrication of transfer adhesives and double faced adhesive
articles with the attributes of the invention on both of the
adhesive surfaces.
[0081] A self wound transfer adhesive can be obtained from the
adhesive article of the invention illustrated above in FIG. 4 by
(a) applying a release coating to the second surface of the release
liner 100 or using a first release liner 100 in which the second
surface is a release surface, and (b) winding the adhesive article
into a roll. The release characteristics of the liner are such that
the adhesive only adheres to one side of the liner when
unwound.
[0082] A single liner double faced adhesive tape can be obtained
from the adhesive article illustrated in FIG. 5 by (a) applying a
release coating to the second surface of the release liner 100 or
using a first release liner 100 in which the second surface is a
release surface, and (b) applying a second adhesive layer (not
shown) having a first surface and a second surface onto the release
surface wherein the first surface of the second adhesive layer is
in contact with the release surface of release liner 100. When this
article is wound the exposed adhesive adheres to the exposed
surface of the facestock. The release characteristics of the liner
are such that one of the adhesives adheres to one side of the liner
when unwound producing a face stock with adhesive on both sides and
a liner adhered to one of the adhesive surfaces.
[0083] FIG. 7 is a perspective view of the adhesive article 114 of
the first embodiment shown in FIG. 4, following removal of the
release liner 100, with the article turned over so that the
adhesive layer 112 is on the lower side of the article depicted in
FIG. 7. As shown in FIG. 7, the adhesive article 114c in this
embodiment includes the second pattern 110 embedded in the
adhesive, and the first pattern 106 substantially on the surface of
the adhesive layer 112. Since the patterns 110 and 106, which were
formed by application of the non-adhesive materials to the release
liner have been transferred to the adhesive layer 112, the patterns
are in reverse position in or on the adhesive layer 112 relative to
the position the patterns were placed in or on the release liner
100. As shown in FIG. 7, the adhesive article 114c, following
removal of the release liner 100, has a continuous layer of
adhesive 112 having a first surface 112c and a back or second
surface 112a (not shown) and end edges 112b; a first pattern 106 of
first non-adhesive material forms having a first exposed surface
106b and an opposed surface 106a in contact with the first surface
112c of the adhesive layer 112 and overlapping surface 110b of the
second pattern 110; and a second pattern 110 of second non-adhesive
material forms having a partially exposed second surface 110b which
is partially in contact with the first surface 106a of pattern 106
where the two patterns overlap, and an opposed first 110a surface
embedded in the adhesive layer 112. The first pattern 106 which was
embedded in the release surface of the release liner now on the
surface of the adhesive layer 112. As shown, each of the first
surfaces 106b and 110b of patterns 106 and 110 of non-adhesive
material forms is in a different plane, and the first pattern 106
is in contact with the first surface 112c of the adhesive layer 112
and protrudes from the adhesive layer 112. The plane formed the
first surfaces 106b corresponds to plane 102b, and the plane formed
by the first surfaces 110b corresponds to plane 102a as illustrated
in and discussed in reference to FIGS. 3, 3' and 3''. The
combination of a non-adhesive pattern 110 in the adhesive and a
second non-adhesive pattern protruding from the same side of the
adhesive layer provides air egress, repositionability and
slideability.
[0084] A second embodiment of the method of the invention is
illustrated in FIGS. 1, 8, 9, 9', 9'', 9''', 10 and 11. The method
of the second embodiment comprises (a) providing a release liner
comprising a molding layer having a release surface and a second
surface; (b) applying a first pattern of a first non-adhesive
material to a first portion of the release surface; (c) applying a
second pattern of a second non-adhesive material to a second
portion of the release surface, wherein the second pattern
partially overlaps the first pattern; (d) embedding at least one of
the first and second non-adhesive materials into the molding layer;
and (e) applying an adhesive layer having a first and second
surface and end edges onto the release liner, wherein the front
surface of the adhesive layer is adhered to the release surface of
the release liner. In this embodiment, the first pattern initially
is not embedded in the molding layer of the release liner. Rather
the second pattern is applied over the first pattern, portions or
all of one or both patterns are embedded in the molding layer, and
the part of the first pattern overlapped by the second pattern is
embedded more deeply into the release liner than the non-overlapped
portions of the first pattern.
[0085] FIGS. 1, 8, 9, 9', 9'', 9''', 10 and 11 are perspective and
cross sectional views depicting the second embodiment of making the
adhesive article outlined above. FIG. 1 is a perspective view of
the release liner 100 on pattern 106, as described above. The
release liner 100 includes the release surface 102, and the molding
layer 104. The first pattern 106 of a first non-adhesive material
has been applied to the release surface 102. In this second
embodiment, the first pattern 106 is not embedded into the release
liner prior to application of a second pattern 210. In the
subsequent figures, for the sake of simplicity, the molding layer
104 is not shown as a separate layer; however, since it is to be
understood that the release liner 100 includes the moldable layer
104, either as a separate layer, or as the material of which the
release liner 100 itself is formed, the entire layer is referred to
by reference numeral 104 to indicate that at least a part of the
release liner 100 is a molding layer 104.
[0086] FIG. 8 is a perspective view of the release liner 100
(molding layer 104), after applying the second pattern 210 of a
second non-adhesive material over the first pattern. The second
pattern 210 is applied in a stepped pattern in this embodiment. In
other embodiments (not shown), depending on the rheology and method
of application of the non-adhesive material, the second pattern may
be applied in a non-stepped form, that is, with some bridging
between the surface of the release liner 100 and the profile of the
first pattern 106. In yet other embodiments (not shown), again
depending on the rheology and method of application of the
non-adhesive material, the second pattern may be applied so that it
steps over the first pattern 106, that is, does not bridge, and at
the same time results in the formation of the second pattern 210
having a substantially planar upper surface between the areas of
overlap, i.e., without the gaps between the crossover points.
[0087] FIGS. 9, 9', 9'' and 9''' depict the release liner 100 after
both the first pattern 106 and the second pattern 210 are embedded
into the release surface 102 and molding layer 104 of the release
liner 100. FIG. 9' is a cross-sectional view taken at line 9'-9' of
FIG. 9, FIG. 9'' is a cross-sectional view taken at line 9''-9'' of
FIG. 9, and FIG. 9' is a cross-sectional view taken at line
9'''-9''' of FIG. 9. In this second embodiment, both the first
pattern 106 and the second pattern 210 are embedded into the
molding layer 104 and the release surface 102. At the points of
overlap, portions of the first pattern 106 are more deeply embedded
into the release surface 102, as shown in FIGS. 9' and 9'''. As
shown in FIG. 9, the exposed upper or second surfaces of both
patterns (106a and 210a, respectively) are substantially level or
flush with the release surface 102. In this embodiment, the first
pattern 106 is at two levels relative to the plane 102a defined by
the release surface 102 of the release liner 100. A first portion
106' remains substantially flush with the surface plane 102a FIG.
9'', while a second portion 106'' is more deeply embedded into the
surface, and is actually below the overlapping portion of the
second pattern 210. In the embodiment shown in FIG. 9, the upper or
second surface 210a of the embedded portion of the first pattern
210 is substantially coplanar with the plane defined by the release
surface 102, while the upper or second surface 106a of the portion
106'' of the first pattern 106 which is overlapped by the second
pattern 210 is below the lower or first surface 210b of the second
pattern 210. In other embodiments, either or both patterns may be
incompletely embedded into the release surface 102 of the release
liner. In such other embodiments, the upper surface of a portion of
the first pattern 106 is still below the lower surface of the
overlapping portion of the second pattern 210. Thus, in this second
embodiment, at least one of the patterns of non-adhesive material
is at least partially overlapped by another pattern, and the
overlapped portion is embedded more deeply into the molding layer
104 than other parts are embedded.
[0088] FIG. 9' is a cross-sectional view of the release liner 100
taken at line 9'-9' of FIG. 9. As shown in FIG. 9' (and in FIGS.
9'' and 9'''), a plane 102a is defined by the release surface 102.
This plane 102a is referred to herein in defining the degree to
which the respective non-adhesive materials are embedded into the
release liner 100. As depicted in FIG. 9', the second surface 210a
of the second pattern 210 remains coplanar with the plane 102a
defined by the release surface 102 of the release liner 100, and a
portion 106'' of the first pattern 106 is embedded more deeply into
the release surface 102.
[0089] Since both patterns 106 and 210 are embedded into the
molding layer 104, the second surface 210a of second pattern 210 is
in the same plane 102a as the surface of the molding layer 104. The
first surface 210b is in a second plane identified in FIGS. 9' as
plane 102b. A portion of second pattern 106 shown as 106'' is below
pattern 210, and the lower or first surface of 106'' is in another
plane identified as 102c.
[0090] In other embodiments (not shown), the second pattern 210 may
be embedded to a depth whereby the upper or second surface 210a of
the second pattern 210 is either above or below the plane 102a. In
these latter embodiments, the second pattern 210 either is only
partially embedded, in which a portion of the second pattern 210
extends above the plane 102a, or is over-embedded, in which the
surface 210a of the second pattern is below the plane 102a.
Similarly, in other embodiments, the first pattern 106 may be over-
or under-embedded. In such embodiments, the resulting surface of
the release liner 100 may have 2 or more different levels, thus
providing a wide range of possible combinations of initial tack,
final tack, air egress, slideability and repositionability when the
adhesive layer is subsequently applied. In any of these variations,
the overlapped portion of the first pattern 106 is below the
remainder of the first pattern 106.
[0091] As shown in FIG. 9'', which is a cross-sectional view taken
at line 9''-9'' of FIG. 9, in some areas of the release liner, the
first pattern 106 is embedded to a level at which its second
surface 106a is exposed and substantially coplanar with the plane
102a, and the surface is not overlapped by the second pattern 210
in these areas.
[0092] FIG. 9''' is a cross-sectional view taken at line 9'''-9'''
of FIG. 9. In this cross-sectional view, the second pattern 210
appears as a three separate pieces, corresponding to the strips
shown in FIG. 9, and the first pattern 106 appears as a stepped
structure (106' and 106''). In this embodiment, in which the upper
surface 210a of the embedded second pattern 210 is substantially
coplanar with the plane 102a, the first pattern 106 forms a strip
having a stepped appearance at the locations of overlap by the
second pattern, which is illustrated in FIG. 9'''. Thus, as shown
by comparing FIGS. 9' and 9'', and by viewing FIG. 9''', the first
pattern 106 is embedded to at least two different depths into the
layer 104. A portion 106'' of the second surface 106a of pattern
106 is in plane 102a, and second surface 106a of another portion
106'' is in plane 102b. In addition, a portion of the first surface
106b of 106'' is in plane 102b and another portion of the first
surface of 106b is in plane 102c.
[0093] Following application of the second pattern 210 and
embedding of both the first pattern 106 and the second pattern 210,
an adhesive layer 112 is transferred onto the release surfaces
102a, release liner 100, thus forming an adhesive article 214, as
shown in FIG. 10. The adhesive layer 112 includes a first surface
112c (facing downward, not shown in FIG. 10), a second surface 112a
and end edges 112b. The first surface 112c of the adhesive layer is
adhered to the release surface 102 of the release liner 100 and the
second surfaces 106a and 210a of the two patterns. The second
surface 112a is exposed on the upper surface of the adhesive
article 214 shown in FIG. 10.
[0094] FIG. 11 is a perspective view of the adhesive article 214 of
the second embodiment shown in FIG. 10, following removal of the
release liner 100, with the article turned over so that the
adhesive layer 112 is on the lower side of the article depicted in
FIG. 11. Since the patterns 210 and 106, formed by application of
the non-adhesive materials to the release liner, in which the both
patterns are embedded in the release liner 100, are transferred to
the adhesive layer 112, the patterns are in reverse position on the
adhesive layer 112 relative to the position in the release liner
100. As shown in FIG. 11, the adhesive article 214a includes:
adhesive layer 112; the second pattern 210 and the partially
overlapping first pattern 106 above the adhesive layer 112 and in
contact with the first surface 112c of the adhesive layer 112; and
portions 106c of the first pattern 106 extending above the first
surface of pattern 210 at the overlap. As shown, each of the
patterns 106 and 210 of non-adhesive material forms has a first
surface 106b and 210b, respectively, and the first surface of the
first pattern 106 is at two different heights (planes 102b and
102c) relative to first surface 112c (plane 102a), one of which is
higher than the first surface 210b of the second pattern 210 (plane
102b). The different heights provide protrusions of non-adhesive
material which comprise air egress, repositionability and
slideability. Stated in the alternative, the first surfaces 210b of
the second pattern 210 are in plane 102b; the first surfaces 106b
of the first pattern 106 are in planes 102b and 102c; and the
planes of the first surfaces 106b and 210b are different from the
plane 102a of the first adhesive surface 112c.
[0095] In one embodiment, not shown with this second embodiment but
substantially similar to the structure shown in FIG. 5 with respect
to the first embodiment, a facestock is applied to the second
surface 112a of the adhesive article 214. In one embodiment, not
shown with this embodiment but substantially similar to the
structure shown in FIG. 6 with respect to the first embodiment, an
additional release liner is applied to the back surface 112a of the
adhesive article 214.
[0096] FIGS. 1, 2, 12a, 12b, 13, 13', 13'' and 14 are perspective
and cross sectional views depicting a third embodiment of making an
adhesive articles of the invention. FIGS. 1 and 2 are perspective
views of a release liner 100 or a first pattern of non-adhesive
material from 106, as described above. In this third embodiment,
the first pattern 106 is embedded into the release liner 100 prior
to subsequent steps, as shown in FIGS. 2 and 2'. However subsequent
steps differ in this embodiment, thus the adhesive article is
identified by the reference numeral 314, in accordance with the
differences between this embodiment and the first and second
embodiments.
[0097] In this third embodiment, rather than applying a second
pattern over the embedded first pattern 106, as in the first
embodiment, the embedded first pattern 106 is removed prior to
application of a second pattern 310. The sequential steps of
embedding the first pattern 106, followed by removal of the first
pattern 106, shown in FIGS. 12a and 12b, results in the formation
of a negative or void, or channeling pattern 122 in the release
liner 100, as shown in FIGS. 12b and 13. As in previous FIGS. 8-10,
molding layer 104 is used to represent the release liner 100.
[0098] FIGS. 12a and 12b are cross-sectional views of the release
liner 100 similar to FIG. 2', except that in FIG. 12a, an adhesive
layer 120 has been applied to the release surface 102. The adhesive
used in the adhesive layer 120 is selected to provide stronger
adhesion to the non-adhesive material forming the first pattern 106
than the adhesion of the non-adhesive material has to the release
surface 102 of molding layer 104. As shown in FIG. 12b, when the
adhesive layer 120 is removed, the non-adhesive material forming
the first pattern 106 is removed with the adhesive layer 120, thus
forming the voids or channels 122 in the molding layer 104.
[0099] In an alternative embodiment to using the sequential steps
of applying a first pattern of non-conductive material forms to the
surface of molding layer, embedding the first pattern, and removing
the first pattern to form voids or channels as shown in FIGS. 12a,
12b and 13, the molding layer 300 of FIG. 13 may be prepared by
directly embossing the first pattern into the surface 102 of
molding layer 104. Any of the embossing procedures known in the art
may be utilized to provide the desired first pattern. For example,
the first pattern may be obtained by applying heat and pressure to
the surface of a molding layer using a roller or platen having the
desired pattern in or on its surface.
[0100] In other embodiments, the non-adhesive material may be
removed by other means, depending on the material of which the
non-adhesive material is formed. For example, the non-adhesive
material may be removed by dissolution with an appropriate solvent,
or by an electrolytic method, or by a physical method. In most
cases, the use of adhesive as described above is suitable.
[0101] FIG. 13 is a perspective view of molding layer 104,
following the removal of the first pattern of non-adhesive material
forms 106. As shown in FIG. 13, removal of the first pattern 106
leaves voids or channels 122 remaining in the surface of the
molding layer 104 in a pattern substantially corresponding to the
first pattern 106. As will be understood, in this embodiment, in
which the first pattern 106 constitutes lines, when the
non-adhesive material of the first pattern 106 is removed, the void
or channel pattern 122 is substantially in the form of similar
lines. In other embodiments, for example where the first pattern
106 includes a line of dots, "dashes" or elongated forms separated
by regions free of the non-adhesive material, a corresponding
similar pattern will be formed when the non-adhesive material is
removed.
[0102] Referring now to FIGS. 14, 14' and 14'', a second
non-adhesive material is applied to the molding layer 104 to form a
second pattern 310 having a second surface 310a and a first surface
310b. The second pattern 310 is applied in a stepped pattern in
this embodiment. In other embodiments (not shown), depending on the
rheology and method of application of the non-adhesive material,
the second pattern may be applied in a non-stepped form, that is,
with some bridging between the surface of the molding layer 104 and
the profile of the channel 122. In yet other embodiments (not
shown), again depending on the rheology and method of application
of the non-adhesive material, the second pattern 310 may be applied
so that it steps into the channel 122, that is, does not bridge,
and at the same time results in the formation of the second pattern
310 having a substantially planar upper surface, i.e., without the
gaps between the crossover points.
[0103] FIG. 14' is a cross-sectional view taken at line 14'-14' of
FIG. 14 and FIG. 14'' is a cross-sectional view taken at line
14''-14'' of FIG. 14. In this third embodiment, some portions 310d
of the second pattern 310 are embedded in the channels 122 in
molding layer 104, and some portions 310c are on the original
release surface 102, as shown in FIG. 14. It is noted that the
portions 310d have not actually been directly embedded as in the
first two embodiments. The embedded portions 310d of the second
pattern 310 are considered to be embedded because when they are
applied into the void or channel 122 left by removal of the first
pattern 106, and the portions 310d are effectively in an embedded
position relative to the plane 102a of the release surface 102 of
molding layer 104. Thus, in this embodiment, the second pattern 310
comprises elements 310c and 310d at two levels relative to the
plane 102a. A first portion 310c remains above the plane 102a,
i.e., not embedded, while a second portion 310d is embedded into
the surface below the plane 102a. In the embodiment shown in FIG.
14', the upper or second surface of the embedded portion 310d of
the second pattern 310 is substantially coplanar with the plane
102a defined by the release surface 102. In other embodiments, the
second 310d portion may be incompletely embedded into the release
surface 102 of the release liner, such that the upper surface of
the portion 310d is above the level of the plane 102a. In another
embodiment, in which the first pattern 106 is over-embedded prior
to its removal, the upper surface of the portion 310d may be below
the plane 102a. In this embodiment, the portion 310d is
substantially at or above the level defined by the plane 102a,
since it is applied directly onto the original release surface
102.
[0104] As shown in FIG. 14'', which is a cross-sectional view taken
at line 14''-14'' of FIG. 14, in some areas of the release liner,
the second pattern 310 is embedded, or fills the channel 122 such
that the upper surface of the portion 310c is substantially
coplanar with the plane 102a, as a result of its being deposited on
the bottom of the channel 122. In other embodiments, the second
pattern 310 may be applied using a non-adhesive material having a
suitable rheology which allows the non-adhesive material to fill
the channel 122 while at the same time filling the gaps between the
portions 310c formed by the step-like application of the pattern
310.
[0105] Following application of the second pattern 310, as shown in
FIG. 14, an adhesive layer 112 is applied over the molding layer
104 and second pattern 310, thus forming an adhesive article 314,
as shown in FIG. 15. The adhesive layer 112 includes a first
surface 112c (facing downward, not shown in FIG. 15), a second
surface 112a and end edges 112b. The first surface 112c of the
adhesive layer is adhered to the release surface 102 of the release
liner 100 and the exposed surface of the second pattern. The second
surface 112a is exposed on the upper surface of the adhesive
article 314 shown in FIG. 15.
[0106] The adhesive structure 314 shown in FIG. 15 (and with
additional reference to FIGS. 14, 14' and 14'') includes a release
liner 100 having a molding layer 104; a continuous layer of
adhesive 112 having a front surface 112c (not shown), a back
surface 112a and end edges 112b, in which the front surface 112a of
the adhesive 112 is adhered to the release surface 102 of molding
layer 104, the first embossed pattern 122 and the second pattern
310. A portion 310d of the second pattern 310 is at least partially
embedded in portions of the first embossed pattern 122.
[0107] FIG. 16 is a perspective view of the adhesive article 314a
of the third embodiment shown in FIG. 15, following removal of the
release liner 100, with the article turned over so that the
adhesive layer 112 is on the lower side of the article depicted in
FIG. 16. As shown in FIG. 16, the adhesive article 314a includes
the second pattern 310 fully embedded in the adhesive, and the
pattern of channels 122 formed by the first pattern 106 revealed as
ridges 122a extending above the first surface 112c of the adhesive
layer 112. The ridges 122a include in some areas the adhesive of
the adhesive layer 112 and in some areas portions 310c of the
second pattern 310, as shown in FIG. 16. The patterns 310 and
channels 122, formed by application of the non-adhesive materials
to the release liner (including removal of the first pattern 106 to
form the channels 122), in which the both the pattern 310 and the
channels 122 are at least partially embedded in the release liner
100, form a negative of the structure eventually formed in the
adhesive layer 112. When the structure is transferred to the
adhesive layer 112, the patterns are in reverse position in or on
the adhesive layer 112 relative to the position in or on the
release liner 100. As shown in FIG. 16, the adhesive article 314a,
following removal of the release liner 100, has a continuous layer
of adhesive 112 having a first surface 112c, a second surface 112a
(not shown) and end edges 112b; a first pattern formed by the
ridges 122a, a second pattern 310 of non-adhesive material forms, a
portion of the pattern 310, which was more deeply embedded in the
release surface of the release liner, now displayed in the ridges
122a of the adhesive layer 112, while the remaining portions of the
non-adhesive material of the pattern are embedded in the surface
112c of the adhesive layer 112. That is, the top or first surface
310b of a portion of second pattern 310 is in the same plane as
first surface 112c of the adhesive layer, and the first surface
310b another portion of second pattern 310 is in a plane that is
different from the plane formed in the other portion of the second
pattern. The first surface of the second pattern in the different
planes provides air egress, repositionability and slideability.
[0108] In the embodiment shown in FIGS. 14, 15 and 16, the second
pattern 310 has been applied at an angle of about 90.degree. to the
direction of the first pattern 106 and of the channel structure
122. As noted earlier, the second pattern may be applied at an
angle of about 30.degree., about 45.degree., about 60.degree.,
about 75.degree. or any other selected angle relative to the
direction of the first pattern 106 and the channel structure
122.
[0109] In one embodiment, the adhesive articles of the invention,
such as adhesive article 314a illustrated in FIG. 16 may be
described as comprising a continuous layer of adhesive having a
first surface and a second surface, and a first embossed pattern in
the first surface of the adhesive layer, and a second pattern of
non-adhesive material forms, wherein the second pattern at least
partially overlaps the first pattern and is embedded in the first
surface of the adhesive layer; each of said embossed pattern and
second pattern has an exposed first surface wherein the first
surface of at least a portion of the first embossed pattern is in a
plane that is different from the plane of the first surface of at
least a portion of the second pattern of non-adhesive forms.
[0110] In one embodiment, not shown with this third embodiment but
substantially similar to the structure shown in FIG. 5 with respect
to the first embodiment, a facestock is applied to the back surface
112a of the adhesive article 314a. In another embodiment, not
shown, an additional release liner is applied to the back surface
112a of the adhesive article 314a.
[0111] The temperatures used to embed the non-adhesive material
form into the molding layer in accordance to the methods of the
invention depend on the materials used, but typically are in the
range of about 150.degree. to about 300.degree. F. (about
65.degree. C. to about 150.degree. C.), or from about 200.degree.
to about 250.degree. F. (about 93.degree. C. to about 121.degree.
C.) for embedding into the release liner. The embedding pressure is
also material dependent and may be between about 25 to about 150
pounds per square inch (psi)(about 1.7 Kg/cm.sup.2 to about 11
Kg/cm.sup.2), or from about 50 to about 100 psi (about 3.5
Kg/cm.sup.2 to about 7 Kg/cm.sup.2).
[0112] FIG. 17 illustrates one embodiment of the embedding process.
The embedding process uses a release liner with a moldable layer
under the release surface, as described herein. In one embodiment,
the molding layer is composed of polyolefins, such as low, medium
and high density polyethylene, propylene or mixtures thereof. In
one embodiment, the molding layer has a thickness of 10 .mu.m to
about 50 .mu.m. In other embodiments, the thickness may be from
about 20 .mu.m to about 70 .mu.m or from about 30 .mu.m to about 60
.mu.m.
[0113] Referring to FIG. 17, a release liner 100 is printed on the
release surface 102 with non-adhesive material in a first pattern
106. The release liner 100 is passed through laminating rollers
124a and 124b. In one embodiment, the release liner and bottom
laminating roller are heated, and the upper laminating roller is
cooled. Other configurations may be used. The materials selected
determine the heating and cooling configurations that may be used.
The laminating rollers may be steel rollers, rubber rollers or a
combination.
[0114] In another embodiment illustrated in FIG. 18, the upper
roller 124a may include a textured surface. The textured surface
may be used for applying the differential height pattern in the
embedding steps of the method of the present invention or the
textured surface may be used to apply the embossed patterns
described herein. FIG. 18 schematically illustrates two possible
embodiments of textured surfaces for use, e.g., on a laminating
roller. In FIG. 18, the roller 124a includes a surface having
either a first texture 126 or a second texture 128. As indicated in
FIG. 18, the scale of the texturing may be quite small, and the
scale is magnified for exemplification. In the first texture 126,
the roller 124a has a substantially square-toothed appearance. In
the second texture 128, the roller 124a has a two-level toothed
appearance. It should be recognized that these textures are
exemplary only, and many other textures may be used.
[0115] While the invention has been explained in relation to its
preferred embodiments, it is to be understood that various
modifications thereof will become apparent to those skilled in the
art upon reading the specification. The features of the various
embodiments of the adhesive articles described herein may be
combined into within an adhesive article. The various methods of
manufacturing the adhesive articles of the present invention
described herein may also be combined. Therefore, it is to be
understood that the invention disclosed herein is intended to cover
such modifications as fall within the scope of the appended
claims.
* * * * *