U.S. patent application number 10/982758 was filed with the patent office on 2005-09-08 for multi-layer dry paint decorative laminate having discoloration prevention barrier.
Invention is credited to Fahlsing, Roger A., Fontana, John Vincent, James, Martin Ian, Kaminski, Anneke Margaret, Shih, Frank Yen-Jer, Zeik, Douglas Bruce.
Application Number | 20050196607 10/982758 |
Document ID | / |
Family ID | 36182414 |
Filed Date | 2005-09-08 |
United States Patent
Application |
20050196607 |
Kind Code |
A1 |
Shih, Frank Yen-Jer ; et
al. |
September 8, 2005 |
Multi-layer dry paint decorative laminate having discoloration
prevention barrier
Abstract
A decorative dry paint wall film includes a layer of dry paint,
a pressure-sensitive adhesive layer on one side of the dry paint
layer, and a release liner in releasable contact with the dry paint
layer on a side opposite from the pressure-sensitive adhesive
(PSA). The release liner has a matte release coat layer that
contacts the dry paint layer. The release liner is released from
the dry paint layer after the PSA side is attached to a wall. The
matte release coat transfers a matte finish to the dry paint layer
when the release liner is removed. The wall film includes a barrier
layer to protect against significant discoloration of the color in
the dry paint layer caused by migration of azo-type pigments from a
painted wall surface. The barrier layer in one embodiment comprises
a dry emulsion containing ethylene-vinyl alcohol and a dispersed
polymeric material which in one embodiment comprises a urethane
material.
Inventors: |
Shih, Frank Yen-Jer;
(Arcadia, CA) ; Fahlsing, Roger A.; (Hobart,
IN) ; Kaminski, Anneke Margaret; (Cincinnati, OH)
; Fontana, John Vincent; (Cincinnati, OH) ; Zeik,
Douglas Bruce; (Middletown, OH) ; James, Martin
Ian; (Montesilvano Colle (Pescara), IT) |
Correspondence
Address: |
CHRISTIE, PARKER & HALE, LLP
PO BOX 7068
PASADENA
CA
91109-7068
US
|
Family ID: |
36182414 |
Appl. No.: |
10/982758 |
Filed: |
November 5, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10982758 |
Nov 5, 2004 |
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10779528 |
Feb 13, 2004 |
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10779528 |
Feb 13, 2004 |
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10457826 |
Jun 9, 2003 |
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Current U.S.
Class: |
428/354 |
Current CPC
Class: |
Y10T 428/28 20150115;
B32B 7/12 20130101; Y10T 428/2848 20150115; E04F 13/002 20130101;
C09J 2423/001 20130101; B32B 27/14 20130101; Y10T 428/1405
20150115; B32B 2260/025 20130101; B32B 2274/00 20130101; B32B
2307/4026 20130101; B32B 27/08 20130101; B32B 2260/046 20130101;
B32B 2607/02 20130101; B44C 1/16 20130101; Y10T 428/1486 20150115;
C09J 2301/414 20200801; C09J 7/50 20180101; B32B 27/306 20130101;
Y10T 428/2839 20150115; Y10S 428/904 20130101; C09J 2429/001
20130101; Y10T 428/1467 20150115; Y10T 428/14 20150115 |
Class at
Publication: |
428/354 |
International
Class: |
B32B 009/00 |
Claims
What is claimed is:
1. A multi-layer decorative laminate for applying a layer of color
to a substrate surface, the laminate comprising: a flexible
decorative dry paint layer comprising a color layer which includes
a resinous binder and a pigment, a pressure-sensitive adhesive
layer overlying a surface of the decorative dry paint layer and
adapted for adhering the laminate to a substrate surface; and a
thin, flexible barrier layer disposed between the adhesive layer
and the color layer, the barrier layer comprising an ethylene vinyl
alcohol material forming a dry film form emulsion that retards
migration of discoloration-causing pigments from a painted surface
of the substrate through the adhesive layer to the color layer.
2. The article according to claim 1 in which the barrier layer
produces a color shift of less than about 0.40 .DELTA.b* C.I.E.
color units at 60.degree. C. for at least 400 hours.
3. The article according to claim 1 in which the barrier layer
retards degradation of the adhesive layer caused by constituents
migrating from the color layer toward the adhesive layer.
4. The article according to claim 1 in which the barrier layer has
a glass transition temperature (T.sub.g) greater than about
50.degree. C.
5. The article according to claim 1 in which the barrier layer
material inhibits migration of azo-type discoloration-causing
pigments.
6. The article according to claim 1 in which the barrier layer
comprises an emulsion containing ethylene-vinyl alcohol blended
with a dispersed polymeric material.
7. The article according to claim 6 in which the dispersed
polymeric material comprises a urethane material.
8. The article according to claim 6 in which the barrier layer
contacts both the pressure-sensitive adhesive layer and the color
layer in the absence of separate adhesive tie layers.
9. The article according to claim 6 in which the ethylene vinyl
alcohol component is thermoplastic or crosslinked.
10. The article according to claim 6 in which the dispersed
polymeric material migrates to form a boundary layer on a side of
the barrier layer.
11. A multi-layer decorative laminate for applying a layer of color
to a substrate surface, the laminate comprising: a flexible
decorative dry paint layer comprising a color layer which includes
a resinous binder and a pigment, a pressure-sensitive adhesive
layer overlying the decorative dry paint layer; and a thin,
flexible barrier coat between the adhesive layer and the color
layer, the barrier coat made from an emulsion of ethylene-vinyl
alcohol copolymer and a migratory polymeric material in dry film
form to provide a barrier layer as a stable emulsion with an
internal boundary layer formed by the migratory polymeric material,
the barrier layer and its internal boundary layer effective to
inhibit migration of discoloration-causing azo-type pigments from a
painted surface of the substrate through the adhesive layer to the
color layer sufficiently to essentially prevent migrating pigments
from a painted surface of the substrate from causing noticeable
color change in the color layer under room temperature
conditions.
12. The process according to claim 11 in which the migratory
polymeric material comprises a urethane material.
13. The process according to claim 11 in which the barrier layer
emulsion is a thermoplastic or crosslinked material.
14. A multi-layer decorative wall film for applying a layer of
color to a substrate surface, the wall film comprising: a flexible
decorative dry paint layer comprising a color layer which includes
a resinous binder and a pigment; a pressure-sensitive adhesive
layer overlying a surface of the dry paint layer and adapted for
adhering the laminate to a substrate surface; a release liner
overlying a surface of the dry paint layer opposite from the
adhesive layer, the release liner removable from the dry paint
layer for exposing an outer surface of the decorative dry paint
layer when the pressure-sensitive adhesive layer adheres the
laminate to the substrate surface and the release liner is peeled
away from the decorative dry paint layer; and a thin, flexible
barrier layer disposed between the adhesive layer and the color
layer, the barrier layer made from an ethylene-vinyl alcohol
material that in dry film form inhibits migration of
discoloration-causing pigments from a painted surface of the
substrate through the adhesive layer to the color layer
sufficiently to retard noticeable color change, caused by such
pigments, from occurring in the color layer under room temperature
conditions.
15. The article according to claim 14 in which the barrier layer
material inhibits migration of azo-type discoloration-causing
pigments.
16. The article according to claim 14 in which the barrier layer
comprises an emulsion containing ethylene-vinyl alcohol and a
dispersed polymeric material.
17. The article according to claim 16 in which the dispersed
polymeric material is selected from the group which includes
urethane, acrylic, polyester resins, ethylene vinyl acetate
copolymer, and combinations thereof.
18. The article according to claim 17 in which the barrier layer
contacts both the pressure-sensitive adhesive layer and the color
layer in the absence of separate adhesive tie layers.
19. The article according to claim 14 in which the decorative dry
paint layer has a dry film thickness from about 0.6 to about 1.6
mils to provide the decorative, protective and opacity properties
sufficient to function as a wall paint.
20. A multi-layer decorative laminate for applying a layer of color
to a substrate surface, the laminate comprising: a flexible
decorative dry paint layer comprising a color layer which includes
a resinous binder and a pigment; a pressure-sensitive adhesive
layer overlying a surface of the decorative dry paint layer and
adapted for adhering the laminate to a substrate surface; a release
liner overlying a surface of the decorative dry paint layer
opposite from the adhesive layer, the release liner removable from
the decorative dry paint layer for exposing an outer surface of the
dry paint layer when the pressure-sensitive adhesive layer adheres
the laminate to the substrate surface and the release liner is
peeled away from the dry paint layer; and a thin, flexible barrier
layer disposed between the adhesive layer and the color layer, the
barrier layer made from an ethylene-vinyl alcohol material that in
dry film form inhibits migration of discoloration-causing azo-type
pigments from a painted surface of the substrate through the
adhesive layer to the color layer, in which the barrier layer
produces a color shift of less than about 0.4 .DELTA.b* C.I.E.
color units at 60.degree. C. for at least 400 hours.
21. The article according to claim 20 in which the barrier layer
comprises an emulsion containing ethylene-vinyl alcohol and a
dispersed polymeric material that improves adhesion of the barrier
layer to the adhesive layer and the color layer.
22. The article according to claim 21 in which the dispersed
polymeric material comprises a urethane material.
23. The article according to claim 22 in which the barrier layer
contacts both the pressure-sensitive adhesive layer and the color
layer in the absence of separate adhesive tie layers.
24. A multi-layer decorative wall film for applying a layer of
color to a substrate surface, the wall film comprising: a flexible
decorative dry paint layer comprising a color layer which includes
a resinous binder and a pigment; a decorative pressure-sensitive
adhesive layer overlying a surface of the dry paint layer and
adapted for adhering the wall film to a substrate surface; and a
thin, flexible barrier layer disposed between the adhesive layer
and the color layer, the barrier layer comprising an emulsion of
ethylene-vinyl alcohol copolymer and a dispersed urethane material
in either a thermoplastic or crosslinked dry film form that reduces
migration of discoloration-causing pigments from a painted surface
of the substrate through the adhesive layer to the color layer.
25. The article according to claim 24 in which the barrier layer
material inhibits migration of azo-type discoloration-causing
pigments to an amount less than about 0.4.DELTA.b* C.I.E. color
units at 60.degree. C. for at least 400 hours.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application
Ser. No. 10/779,528, filed Feb. 13, 2004, which is a
continuation-in-part of application Ser. No. 10/457,826, filed Jun.
9, 2003. These applications are incorporated herein in their
entirety by this reference.
FIELD OF THE INVENTION
[0002] This invention relates to dry paint transfer laminates, and
more particularly, to decorative laminates or wall films for
applying a layer of color to a wall surface. The wall film of this
invention resists discoloration caused by pigments or dyes
migrating from a painted wall surface into the color-producing
layers of the wall film.
BACKGROUND
[0003] Thin sheets of decorative multi-layer dry paint laminates or
wall films may be adhesively applied to a painted surface by a
bonding layer, typically adhesive, for applying color to the
surface. The wall film of this invention provides an alternative to
conventional wallpaper. The familiar steps of applying wallpaper
paste to conventional wallpaper or immersing pre-pasted wallpaper
in water are time consuming, messy and require additional cleanup.
These problems are avoided by the wall film of this invention which
can be applied and repositioned on the wall in much less time.
Special color effects such as faux finishes can be applied in a
single application, and the wall film can be applied with
overlapping seams that virtually disappear and are, therefore, not
noticeable when the wall is viewed even close up and at different
angles. The wall film as applied to the wall is exceedingly thin,
much thinner than conventional wallpaper, so that by applying the
wall film with overlapping seams that are virtually unnoticeable, a
room can be decorated with new color effects that speed the process
when compared with applying conventional wallpaper.
[0004] The wall film of this invention generally comprises a dry
paint transfer sheet having one or more decorative layers of dry
paint which can include a pigmented dry paint layer or color layer,
a transparent protective clear coat layer, and one or more print
coats which can provide various visual designs such as a faux
pattern, if desired. An adhesive layer such as a pressure sensitive
adhesive is applied to the decorative dry paint layer.
[0005] The decorative paint layer portion of the wall film
preferably comprises a pigmented layer or layers of dry paint that
simulate conventional interior wall paint. The wall film can be
applied to suitable surfaces, such as flat two-dimensional interior
wall surfaces; but the film is sufficiently flexible to be applied
to match corners and to fit solidly around curved wall surfaces as
well.
[0006] Foreign substances or agents in or on the wall surface, such
as pigments in a painted surface, may be solubilized (i.e.,
dissolve) into the bonding layer of the wall film and migrate to
the pigmented color-producing layer or layers of the wall film.
Discoloration of the wall film may be produced by organic pigments
or dyes found in common wall paints that migrate through the
bonding layer into the color-producing layers of the wall film. For
example, azo-type pigments used in wall paints containing yellow
pigments as a component, or to a lesser extent, orange or red
pigments or dyes, can migrate and cause discoloration.
[0007] The present invention provides a multi-layer wall film
adapted for contact with a painted substrate surface that may
contain organic materials with color constituents that migrate. The
invention addresses a situation, in particular, where the painted
surface containing such organic color components may not be
modified to avoid the color migration problem. In response to this
problem, the invention provides a wall film containing one or more
barrier layers that cooperate to block or capture the migrating
color materials, and in particular, those containing azo-type
pigments. The barrier layer inhibits long-term discoloration of the
color layer or layers in the wall film caused by the film being in
contact with such a painted surface.
[0008] Although a barrier layer may be incorporated into the wall
film to inhibit or prevent long-term discoloration of the
color-producing layers, addition of the barrier layer should not
adversely affect other necessary properties of the wall film. These
properties include, but are not limited to, elongation or
flexibility, and intercoat adhesion. Coat weight (or dry film
thickness) of the barrier layer also is an important criterion
inasmuch as the overall thickness of the wall film should stay
below a certain level so that the film, in use, can be applied
without visibly perceptible seams along overlapping sections of the
film.
SUMMARY OF THE INVENTION
[0009] Briefly, one embodiment of the invention comprises a
multi-layer laminate for providing a layer of color to a painted
surface. The laminate includes a decorative dry paint layer and a
pressure-sensitive adhesive layer for adhering the laminate to the
painted surface. The laminate includes one or more barrier layers
that slow or stop migration of discoloration-causing pigments or
dyes from the surface, through the adhesive layer, to the color
layer of the laminate. In one embodiment, the barrier layer will
slow or stop discoloration caused by azo-type pigments in interior
latex paint.
[0010] One embodiment of the invention comprises a multi-layer
decorative wall film having a decorative dry paint layer which
includes a color layer of dry paint, a pressure-sensitive adhesive
layer on one side of the color layer, and a release liner in
releasable contact with the decorative dry paint layer on a side
opposite from the pressure-sensitive adhesive. A barrier layer is
positioned between the decorative dry paint layer and the
pressure-sensitive adhesive layer. The pressure-sensitive adhesive
is adapted for adhering the wall film to a substrate surface. The
substrate surface can be a painted wall surface containing dyes or
pigments that can migrate through the adhesive layer and discolor
the dry paint layer. In use, the adhesive layer adheres the wall
film to the surface under application of pressure, the release
liner is peeled away to expose the dry paint layer, and the barrier
layer effectively retards migration of pigments or dyes from the
surface to the dry paint layer.
[0011] In one embodiment, the barrier layer comprises a thin,
flexible layer containing a copolymer of ethylene-vinyl alcohol
(EVOH) in a form effective for preventing or appreciably retarding
migration of discoloration-causing constituents from the painted
surface through the adhesive layer to the color layer. Accelerated
aging tests on yellow dye migration have shown substantial
improvements in discoloration prevention for various forms of the
invention, when compared with similar wall films having no such
barrier between a color layer and an adhesive layer. One embodiment
of the barrier layer comprises a modified EVOH-based barrier coat
in which a polymeric material is blended with an EVOH copolymer to
form a stable barrier film that improves barrier properties and
other functional properties of the wall film. One embodiment in
which the EVOH barrier material is blended with a urethane material
improves a number of significant performance properties of the wall
film. These include mechanical properties such as elongation and
tensile strength and inter-layer adhesion, in addition to providing
an improved barrier against migrating discoloration-causing agents.
The barrier layer also stabilizes adhesive properties by retarding
unwanted constituents migrating from the color coat layer into the
adhesive layer.
[0012] The barrier layer is particularly useful in retarding
transmission of azo-type pigments while present at a low coat
weight or film thickness which does not significantly increase the
overall thickness of the wall film. Use of the barrier layer
provides a means to increase the amount of pigment in the color
coat to increase film opacity without loss of flexibility or
tensile strength.
[0013] These and other aspects of the invention will be more fully
understood by referring to the following detailed description and
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic cross-sectional view illustrating one
embodiment of a multi-layer dry paint transfer laminate according
to principles of this invention.
[0015] FIG. 2 is a schematic illustration of the dry paint transfer
laminate self-wound into a roll form.
[0016] FIG. 3 is a schematic cross-sectional view illustrating an
alternative embodiment of the invention.
[0017] FIG. 4 is a graph which illustrates the data presented in
Example 7.
DETAILED DESCRIPTION
[0018] Referring to FIG. 1, a multilayer dry paint transfer
laminate 10, also referred to as a wall film, is adapted for use as
a surfacing film. The wall film may be used in applications for
providing a layer of color, or special color effects or patterns,
to interior wall surfaces. As such, the wall film is adapted to be
applied to an interior wall surface under ambient room temperature
conditions. Moreover, the wall film is intended to maintain its
function of providing the layer of color over an extended useful
life of the film, while exposed to such interior ambient room
temperature conditions. The layer of color is provided by a
flexible protective and decorative dry paint film layer having
attributes of abrasion resistance, solvent resistance and opacity
similar to conventional wall paints. The wall film also is adapted
to be applied directly to painted interior wall surfaces, without
the need for special treatment to provide the necessary adhesion of
the film to the surface. The wall film in more general terms is
adapted for application to architectural surfaces such as walls of
buildings, building fixtures or appliances, furniture, and the
like. The wall film also can be applied to exterior as well as
interior walls of buildings, and it can be applied so as to provide
special color treatments such as borders or to sections of interior
walls or exterior surfaces.
[0019] The wall film comprises one or more decorative layers which
include a pigmented dry paint layer 12 comprising a synthetic
resinous binder containing a dispersed pigment. The pigmented dry
paint layer 12, also referred to herein as a color layer, can be a
monocoat pigmented layer, or it can be combined with additional
pigmented dry paint layers, coatings or print coats. The decorative
portion of the wall film can include an optically transparent
synthetic resinous clear coat layer 14 adhered to a surface of the
pigmented dry paint layer 12. The clear coat layer provides a
protective abrasion-resistant and solvent resistant topcoat for the
underlying color layer or layers. These decorative elements of the
multilayer dry paint transfer laminate, which may comprise the
color layer or layers, print coats and the clear coat layer or
layers are referred to herein as a "decorative dry paint
layer."
[0020] The wall film further includes a flexible polymeric barrier
layer 16 according to principles of this invention. The barrier
layer 16 overlies and is adhered to the pigmented dry paint layer
12 on a side opposite the clear coat layer 14. A dry
pressure-sensitive adhesive layer 18 overlies and is adhered to a
side of the barrier layer opposite the decorative dry paint layer.
The barrier layer 16 is used to inhibit or prevent undesired
migration of constituents between the adhesive layer and the
decorative dry paint layer. As mentioned, such barrier properties
include reducing or avoiding undesired discoloration by inhibiting
or preventing migration of pigments or dyes from a painted
substrate surface through the pressure-sensitive adhesive layer to
the decorative dry paint layer. Further details of the barrier
layer in its various embodiments are described below.
[0021] On an opposite side of the wall film, a flexible and
foldable release liner 20 overlies and is releasably adhered to the
clear coat layer 14. The release liner has a matte release coat 22
on its inner surface for releasably adhering the release liner 20
to a surface 24 of the clear coat layer 14. In use, the release
liner 20 is peeled away from the clear coat layer to expose the
decorative dry paint layer. The matte release coat 22 separates
from the clear coat layer but remains adhered to the release liner
20 when the release liner is peeled away from the rest of the wall
film. The release liner 20 also has an adhesive release coat layer
26 on a surface opposite from the decorative layer. An exposed
outer surface 28 of the adhesive release coat layer 26 is adapted
for releasably contacting an exposed outer surface 30 of the
adhesive layer 18 when the laminate is wound in a roll form as
illustrated in FIG. 2.
[0022] Referring to FIG. 2, the wall film 10 is self-wound into a
roll form with the outer exposed surface 28 of the adhesive release
coat layer 26 in releasable contact with the exposed outer surface
30 of the adhesive layer 18. Thus, when the wall film 10
illustrated in FIG. 2 is unwound, the adhesive release coat layer
26 on the release liner separates from the outer surface 30 of the
adhesive layer 18 and remains adhered to the release liner 20. The
matte release coat 22 remains adhered to the dry paint layer.
[0023] FIG. 1 illustrates one embodiment of a wall film in which
opposite sides of the barrier layer 16 are in contact with the
adhesive layer 18 and the color layer 12. Other embodiments of the
wall film also can be used with a barrier layer according to this
invention. These include a multi-layer wall film similar to the
FIG. 1 embodiment except that the decorative portion of the wall
film may comprise a monocoat pigmented dry paint layer, omitting
the clear coat layer. In this instance, the matte release liner
transfers a low gloss surface to an exposed outer surface of the
monocoat layer. The decorative portion of the laminate also can
include one or more decorative dry print coat layers to provide
various decorative print patterns between the pigmented dry paint
layer and the clear coat layer.
[0024] Certain embodiments of the invention may include one or more
thin, flexible polymeric dry adhesive layers or tie coats for
improving intercoat adhesion between various overlying layers of
the wall film. One such embodiment is illustrated in FIG. 3 in
which a first tie coat layer 36 is positioned between the barrier
layer 16 and the pigmented dry paint layer 12 and a second tie coat
layer 34 is positioned between the barrier layer 16 and the
pressure-sensitive adhesive layer 18.
[0025] The multi-layer laminate also can include a flexible
reinforcing layer (not shown), also referred to as a support layer,
between the pigmented dry paint layer and the adhesive layer. In
this instance, the barrier layer may be applied between the print
coat layer and the reinforcing layer, or the barrier layer may be
applied between the adhesive layer and the reinforcing layer. The
reinforcing layer can provide a means of structural support for the
decorative dry paint layer and can provide additional opacity for
the pigmented dry paint layer. The reinforcing layer may also have
a tensile strength that exceeds that of the pigmented dry paint
layer.
[0026] Examples of various embodiments of multi-layer decorative
dry paint laminates which can be used with the wall film of this
invention are described in more detail in U.S. patent application
entitled "Multi-Layer Dry Paint Decorative Laminate Having
Discoloration Prevention Barrier," application Ser. No. 10/779,528,
filed Feb. 13, 2004, assigned to Avery Dennison Corporation, which
is incorporated herein by reference in its entirety.
[0027] The portion of the wall film applied to the substrate
surface (i.e., the clear coat 14, color layer 12, barrier coat 16
and adhesive layer 18) has a desired low thickness level, to
minimize visible seams if adjacent wall films are overlapped during
use. The overall film thickness of the wall film as applied to the
wall in its finished state (omitting the matte release liner) is
preferably less than about 3.0 mils, and more preferably less than
about 2.0 mils. In one embodiment, the wall film has a total
thickness of less than about 1.6 mils.
[0028] The pigmented dry paint layer 12 may have a thickness
generally of about 0.5 to about 1.5 mils, in one embodiment about
0.5 to about 1.2 mils, and in another embodiment from about 0.5 to
about 0.9 mil. The thickness of the clear coat layer may range
generally from about 0.05 to from about 0.4 mil, and in one
embodiment from about 0.05 to about 0.3 mil. In one embodiment, the
thickness of the flexible decorative dry paint film (clear coat,
color layer and optional print coats) is between about 0.6 to about
1.6 mils.
[0029] The barrier layer 16, when formed as a discrete layer, may
have a thickness of less than about 0.25 mils (approximately 6
microns) as described in more detail below.
[0030] The thickness of the adhesive layer 18 may range generally
from about 0.4 to about one mil, in one embodiment from about 0.4
to about 0.8 mil, and in another embodiment from about 0.4 to about
0.6 mil.
[0031] The thickness of the release liner 20 may range generally
from about 0.5 to about 2 mils, in one embodiment from about 0.5 to
about 1.5 mils, and in another embodiment from about 0.85 to about
1.05 mils. The thickness of the matte release coat 22 may range
generally from about 0.05 to about 0.3 mil, and in one embodiment
from about 0.1 to about 0.2 mil.
[0032] The thickness of the adhesive release coat layer 26 may
range from about 0.04 to about 0.2 mil, in one embodiment from
about 0.04 to about 0.15 mil, and in another embodiment from about
0.04 to about 0.08 mil.
[0033] Each of the foregoing thicknesses are dry film
thicknesses.
[0034] Dry Paint Layer and Print Coats
[0035] Generally speaking, the paint composition useful in this
invention comprises a solid coloring material, i.e., one or more
pigments, suspended in a liquid medium and applied to the carrier,
followed by drying to a flexible opaque dry paint film that
provides a protective and decorative coating to an architectural
wall surface, similar to a conventional wall paint.
[0036] The pigmented dry paint layer or layers 12 may comprise one
or more polymeric binders or resins and one or more pigments
uniformly dispersed in the binder or resin. These layers may be
made from solvent cast liquid paint compositions comprising the one
or more binders or resins. These compositions may be dispersed in
water or in one or more organic solvents, and optionally may
contain one or more additional additives for controlling processing
properties. The pigmented dry paint layer in one embodiment is
essentially non-fibrous, and is applied as a thin liquid film
coating which dries to a flexible opaque paint film layer. The
paint layer may be applied by coating techniques such as roll
coating including reverse roll coating, gravure printing including
reverse gravure, slot die, and curtain coating. The pigmented dry
paint layers, or the clear coat layer, or the barrier layer may
each comprise independently one or more extruded layers, including
co-extrusion and extrusion coating.
[0037] Any binder or resin conventionally used in wall paint
formulations may be used. The binder may comprise a thermoplastic
or thermosetting resin. Examples of useful binders or resins
generally include synthetic latex resins, acrylic, vinyl,
polyester, alkyd, butadiene, styrene, urethane and epoxy resins and
mixtures thereof. More specifically, the binder or resin may
include one or more polystyrenes; polyolefins, including
polyethylenes and polypropylenes; polyamides; polyesters;
polycarbonates; polyvinylidene fluoride; polyvinyl chloride;
polyvinyl alcohol; polyethylene vinyl alcohol; polyurethanes,
including aliphatic and aromatic polyurethanes; polyacrylates;
polyvinyl acetates; ionomer resins, and mixtures thereof.
[0038] The pigment may be any pigment used in making decorative
coatings. These include opacifying pigments, such as titanium
dioxide and zinc oxide, as well as tinting pigments known in the
art. Filler pigments, such as clay, silica, talc, calcium
carbonate, kaolin clay and mica, can be added as well in
conventional amounts traditionally used in coating and paint
formulations.
[0039] The solvent may be one or more organic-based solvents or
water, or a water-based solution may be used to form an aqueous
emulsion with the binder or resin. Water-based solutions include
water-alcohol mixtures.
[0040] Additional ingredients that may be used include wetting
agents; plasticizers; suspension aids; coalescing agents,
surfactants, thickeners, thixotropic agents such as silica; water
repellant additives such as polysiloxane compounds; fire retardant
additives; biocides; bactericides; defoamers; and flow agents.
[0041] The pigment concentration for the liquid paint or coating
composition used to form the dry paint layers may range from about
10% to about 30% by weight, and in one embodiment from about 13% to
about 27% by weight. The binder or resin concentration may range
from about 20% to about 40% by weight, and in one embodiment from
about 22% to about 37% by weight. The water or organic solvent
concentration may range from about 30% to about 70% by weight, and
in one embodiment from about 40% to about 60% by weight. Additional
ingredients such as wetting agents, suspension agents, etc., may
have concentrations up to about 5% by weight. The coating or paint
compositions used in making the dry paint layers may have a pigment
volume concentration (pigment volume divided by total volume of non
volatile components) from about 9% to about 16%. Pigment volume
concentration can control the flexibility of the decorative film
and its ability to be properly repositioned. Too much pigment can
make the film too brittle; a low pigment volume concentration can
produce a film which stretches excessively.
[0042] Other binder materials, inorganic fillers,
adhesion-promoting materials, solvents, additives and processing
aids which can be used to form the color layers of the wall film
are described in further detail in application Ser. No. 10/779,528,
referred to above.
[0043] Transparent Clear Coat Layer
[0044] The clear coat layer 14 may comprise a single coating layer
or multiple coats, and may comprise any of the polymeric binder
materials described above for use in the color layer. The clear
coat layer also may be formulated from the various solvents
referred to above and applied by the casting or coating techniques
described above. As mentioned, the clear coat layer also may be
extruded. In one embodiment, the clear coat layer can contain a
dispersed filler such as silica to lower the gloss of the matte
finish on the wall film. The clear coat layer cooperates with the
color layer to provide a flexible decorative dry paint film having
the protective qualities of abrasion resistance, water or solvent
resistance and toughness of conventional paint. The clear coat
layer provides enhanced scuff resistance, stain resistance and/or
recoatability to the pigmented dry paint layer or layers underlying
it. The clear coat material adheres to the release liner, is
adapted to release from the release liner during use and provide
the necessary level of surface gloss. In one embodiment, the clear
coat layer comprises a dry topcoat containing an acrylic resinous
material.
[0045] Reinforcing Layer
[0046] The optional reinforcing layer may be formed from any of the
binder or resin materials described above. This layer may be formed
from a solution or an emulsion and applied using any of the coating
techniques described below. This layer also may be extruded. The
reinforcing layer may contain one or more of the above-described
pigments to enhance opacity of the wall film.
[0047] Pressure-Sensitive Adhesive Layer
[0048] The dry adhesive layer 18 may comprise a pressure-sensitive
adhesive (PSA) which bonds the decorative laminate to a substrate
surface, under applied pressure, at room temperature. In one
embodiment, the adhesive layer is a repositionable adhesive, having
a low initial tack that allows slight movement of the laminate to
allow positioning adjustments prior to forming a more permanent
bond. The adhesive has a suppressed initial level of tack at room
temperature that allows the laminate to adhere to a substrate
surface and be repositioned thereon followed by removal of the
matte release liner from the decorative dry paint layer. The
adhesive layer undergoes a subsequent buildup of adhesion due to
the passage of time sufficient to permanently bond the dry paint
layer to the substrate. The adhesive layer is characterized by
producing only a limited amount of ooze beyond the borders of the
laminate when the laminate is applied to a substrate. ("Ooze" is
defined as the flow over time of the adhesive beyond the edge of
the laminate structure.) In one embodiment, no ooze is
produced.
[0049] Generally speaking, the adhesive is selected from the group
consisting of: pressure senstive; water based; water borne; solvent
based; ultraviolet and e-beam cured adhesives; hot melt pressure
sensitive adhesives; water-based pressure sensitive adhesives;
water-borne pressure sensitive adhesives; static adhesives; static
adhesives; electrostatic adhesives; and combinations thereof.
[0050] In one embodiment of the invention described below, the
pressure-sensitive adhesive comprises a cross-linked acrylic
resinous material, and more particularly, a cross-linked acrylic
emulsion. A particularly useful adhesive material comprises an
internally cross-linked acrylic emulsion. High molecular weight
acrylic adhesives and externally cross-linked acrylic adhesives
also may be used to produce the desired combination of functional
properties.
[0051] In addition to the acrylic-based adhesive, the
pressure-sensitive adhesive may comprise a rubber-based adhesive,
vinyl ether adhesive, silicone adhesive, or mixtures thereof. The
pressure sensitive adhesive may be applied to the wall film as a
hot melt, an organic solvent-based or water-based adhesive.
[0052] The adhesive layer also may contain one or more pigments to
enhance the opacity of the paint film layers overlying it and
permit use of thinner paint film layers to achieve desired levels
of opacity. Any of the pigments identified above may be used.
Examples include titanium dioxide and carbon black. The pigment
volume concentration may range up to about 10%, in one embodiment
from about 5% to about 10%, and in another embodiment from about 2%
to about 8%.
[0053] A pressure sensitive adhesive useful for the wall film has
relatively low tack and peel force levels and relatively low room
temperature flow properties. Acrylic emulsion PSAs are particularly
useful when such PSAs have a level of crosslinking that produces an
adhesive material with a relatively high cohesive strength that
yields a desirable combination of low tack, peel and flow
properties. Examples of useful PSAs in which the level of
crosslinking can be appropriately adjusted include acrylic emulsion
PSAs such as pure polymer (butyl acrylate or 2-ethyl hexyl acrylate
or 2-ethyl hexyl acrylate/butyl acrylate) PSAs or similar pigmented
polymer and copolymer materials.
[0054] A particularly useful PSA is an internally cross-linked
acrylic emulsion PSA such as a non-tackified cross-linked copolymer
emulsion of butyl acrylate and 2-ethyl hexyl acrylate. This
adhesive is available from Avery Dennison Corporation as product
no. S-3506. A pigmented form of this PSA comprises 96.8% S-3506
adhesive resin, 2.87% UCD 1106E titanium dioxide, and 0.33% UCD
1507E carbon black.
[0055] Other pressure-sensitive adhesive materials which may be
useful in this invention are described in more detail in U.S.
application Ser. No. 10/779,528.
[0056] Barrier Layer
[0057] The barrier layer 16 stops or retards transmission of
undesired discoloration-causing pigments to effectively maintain
discoloration or color shift of the color layer to within a level
which is essentially unnoticeable for a useful life of the wall
film. Accelerated aging tests described herein provide objective
measurements for defining a reasonable long-term resistance to
discoloration under normal use conditions. Normal use conditions
under which the decorative film is applied and normally in use are
room temperature conditions defined generally as temperatures from
about 4.degree. C. (40.degree. F.) to about 35.degree. C.
(90.degree. F.), and more particularly, from about 15.degree. C.
(60.degree. F.) to about 27.degree. C. (80.degree. F.).
[0058] To approximate and predict the amount of color shift that
may occur during an estimated useful life of the wall film under
normal use conditions, film samples are tested by accelerated aging
techniques and measured for color shift under those conditions.
(Higher temperatures accelerate migration of discoloration-causing
constituents.) In one test method, color shift is measured by
comparing the color of an interior latex test sample with an
interior latex color standard and then subjecting the test sample
and the standard to a 60.degree. C. (140.degree. F.) environment
for approximately 400 hours (16 days). In another accelerated aging
test, wall films and a test standard are subjected to different
temperatures from 40.degree. C. up to 90.degree. C. for about 1,000
hours at each temperature. The test sample is measured for color
shift and compared with a standard to determine the amount of color
shift.
[0059] According to one test, color shift is measured under ASTM
E1164, E308 and 805 test procedures. The unit of measure is C.I.E.
b* (yellow to blue axis). The change in color, delta b*, is
calculated by subtracting the standard b* value from the test
sample b* value. Other color shift measurements can be used to
determine whether color shift is within a specified range. The
color shift measuring techniques are useful in evaluating whether a
color shift is acceptably low by measuring the color shift in a
blue painted sample caused by migration of yellow color
constituents from mono-azo pigments or dyes. In one embodiment, the
color shift is considered sufficiently low to be within an
acceptable range for wall films of this invention if testing at
60.degree. C. for 400 hours produces a color shift equal to or less
than about 0.40 C.I.E. .DELTA.b* color units. Tests have shown such
a low color shift for the barrier coats of this invention for at
least 1,000 hours.
[0060] The various test methods described herein have demonstrated
that the barrier layer 16 of this invention retards transmission of
azo-type color constituents from a painted surface, through a PSA
layer, and into the dry paint color layer, when compared with a
similar wall film not containing such a barrier layer. Hansa 10G
Yellow and Pigment Yellow 74 are examples of azo-type pigments that
can migrate through the wall film. Pilot tests have shown that the
barrier layer is effective in stopping migration of Hansa 10G
Yellow and Pigment Yellow 74 from a painted wall surface to the
decorative color layer of the wall film at 90.degree. C. for a
minimum of 48 hours, whereas the same wall film without such a
barrier will show discoloration virtually immediately under the
same conditions.
[0061] The barrier layer 16 generally comprises a hydrolyzed
copolymer of vinyl acetate and ethylene, and more specifically,
ethylene-vinyl alcohol copolymer (EVOH). A barrier layer containing
this barrier material is applied in a film form that effectively
retards migration of azo-type dyes to within acceptable C.I.E.
.DELTA.b* standards when subjected to various accelerated aging
tests. Such tests have shown that an EVOH containing barrier stops
yellow dye migration at a coat weight of 4 gsm for 1,000 hours of
testing at 60.degree. C. Such barrier properties show color shift
well below 0.40 C.I.E. .DELTA.b* color units.
[0062] In one form of the invention, the EVOH copolymer barrier
material is blended with a thermoplastic polymeric material that
provides a modified EVOH-based barrier material having effective
barrier properties when the barrier coating is in dry film form. In
one embodiment, the EVOH component is blended with a polyurethane
material to form a two-phase system. The solids contained in this
blended barrier material generally include from about 70% to about
95% by weight EVOH and from about 5% to about 30% by weight
thermoplastic urethane. The copolymer of ethylene and vinyl alcohol
used in the barrier material is a commercially available material
such as Soarnol available from Nippon Goshei Co., Ltd. Soarnol
D-2908 is a preferred EVOH material and contains about 29 mol
percent ethylene. The generally preferred EVOH copolymer material
will have an average ethylene content from about 20 mol percent to
about 45 mol percent. In general, the lower ethylene content
(higher vinyl alcohol content) in an EVOH copolymer results in a
stronger barrier to migration of organics such as azo-type dyes. In
one embodiment, it is preferred to use a waterborne polyurethane
polymer as the polymeric material blended with the EVOH. The
urethane material may comprise an aliphatic polyester thermoplastic
urethane such as Sancure 899 available from Noveon. The
urethane-based polymeric material blended with the EVOH also can
comprise an aromatic polyester thermoplastic urethane material,
such as Noveon's Sancure 1511.
[0063] The blended EVOH/urethane barrier material is preferably a
thermoplastic barrier material, although in other embodiments of
the barrier, the EVOH may be modified by adding crosslinking
materials to enhance barrier properties. Crosslinking of the
barrier material also can improve water/humidity resistance of the
EVOH. Optional minor amounts of crosslinking agents may be added,
e.g., from about 2% to about 10% polyaziridene crosslinking resin,
from about 3% to about 6% melamine-HCHO, or mixtures thereof. Use
of the crosslinked barrier material can enhance barrier properties
useful in producing the desired resistance to color migration.
Crosslinking of the barrier material may reduce elongation and
increase tensile strength, but the differences are not considered
significant when compared with a thermoplastic (non-crosslinked)
barrier material. Low crosslink density is preferred to avoid
adversely affecting interlayer adhesion
[0064] The barrier material is processed to yield its film-forming
properties by combining the EVOH resinous material with a solvent
such as 50% water and 50% isopropyl alcohol (IPA) be weight. A
portion of the IPA can be replaced by n-butanol which assists in
processing by preventing the barrier film from drying too quickly.
Use of the organic solvent, such as IPA, as opposed to using a
purely aqueous solvent, improves processing of the EVOH into a
stable emulsion barrier film. The solvent containing 50% water/50%
IPA yields a barrier coating in which the EVOH/urethane blend
comprises about 16% of the total emulsion by weight. This amount of
resin solids in the blended material can vary from about 9% to
about 24% by weight.
[0065] The resulting barrier material can be applied by a coating
process, such as die coating or gravure coating. The barrier film
is heated and dried to a dry film thickness of preferably below
about 6 microns. In one embodiment, a dry film barrier layer
comprising a blend of EVOH and a polyurethane material has a dry
film thickness from about 2.5 to about 4.5 microns.
[0066] The EVOH-based barrier layer of this invention can be made
in different forms, including: (1) a barrier material comprising a
thermoplastic (non-crosslinked) EVOH-based film, (2) a barrier
material in which EVOH is crosslinked by addition crosslinking
agents such as those described above, (3) a barrier material
comprising EVOH blended with a polymeric material such as the
urethane material described above, and (4) a barrier material
comprising a blend of EVOH and a polymeric material such as
polyurethane in which the EVOH component is crosslinked by added
crosslinking agents.
[0067] These forms of the EVOH-based barrier layers have been shown
to produce improved barrier properties that resist migration of
discoloration-causing agents when compared with similar wall films
having no such barrier layer. The barrier properties include not
only resistance to yellow dye migration through the PSA layer to
the color layer, but also resistance to migration of constituents
from the pigmented color coat layer to the PSA layer, and
resistance to migration of constituents from the PSA layer into the
color coat layer. The barrier layer, in particular, may resist
migration of constituents such as plasticizers, heat stabilizers
solvents, surfactants/dispersants and pigments from the color coat
to the PSA layer, and may resist migration of solvents, tackifiers,
fillers, plasticizers, antioxidants and pigments from the PSA layer
to the color coat layer, for example. Tests have shown improved PSA
performance (resistance to weakening of the PSA layer) when using
the barrier coat, when compared with a color coat in contact with
the PSA layer, i.e., no intervening barrier layer.
[0068] The barrier coats consisting primarily of EVOH copolymer
generally require tie coats on opposite sides to provide sufficient
intercoat adhesion to the color coat and to the PSA. Such adhesive
tie coats generally can comprise an acrylic resin such as Elvacite
2042, organic solvents such as MEK and MibK, and a PSA material
such as Avery Dennison's AS346OU for a tie coat between the color
layer and the barrier layer. A tie coat comprising an Avery
Dennison S-3506 PSA can provide a tie coat between the EVOH barrier
layer and the PSA layer.
[0069] The barrier films made with EVOH blended with a polymeric
material such as polyurethane generally maintain good barrier
properties while improving interface adhesion to the color coat and
PSA. These barrier layers show resistance to yellow dye migration
through the wall film when subjected to aging tests conditions over
a wide range of elevated temperatures. These improved barrier
properties are produced using the thermoplastic EVOH/urethane
barrier layer in the absence of tie coats on either side of the
barrier layer. The barrier layer itself provides sufficient
intercoat adhesion to act as a good tie coat between the PSA and
color layers. This improvement in intercoat adhesion can reduce
overall wall film thickness by avoiding the added film thickness
required by tie coats on either side of the barrier layer. In
addition, this barrier layer material provides improved processing
in that the barrier layer can be applied in a single pass through a
coater, between the color layer and the PSA.
[0070] The thermoplastic EVOH/urethane barrier layer also provides
improvements in film toughness as demonstrated by increased tensile
strength and elongation of the wall film when compared with wall
films having no barrier layer and wall films having a barrier made
from acrylic-based materials or unmodified EVOH. Enhanced film
toughness improves film handling properties including resistance to
tearing, flexibility for proper positioning on the wall and around
corners, and repositioning of the wall film. Use of the barrier
layer in the absence of tie coats on opposite sides also can
accommodate more pigment in the color coat without losing
flexibility. Added pigment generally can lower film tensile
strength, but the modified EVOH barrier material improves film
toughness, allowing use of more pigment, thereby improving opacity.
Added pigment also can allow for better color matching.
[0071] The EVOH and polyurethane materials are blended with
solvents to form a stable emulsion which can be formed as a film by
die coating or gravure techniques and dried under elevated
temperatures. Cross sectional photomicrograph images show that the
dispersed polyurethane material migrates to both surfaces of the
barrier layer emulsion in dry form, forming boundary layers of the
polyurethane material. These boundary or skin layers improve
adhesion of the EVOH barrier to the color coat and to the PSA.
[0072] The EVOH component of the blended EVOH/urethane material can
be crosslinked by minor amounts of crosslinking agents added to the
emulsion. Various crosslinking agents have been tested and such
crosslinked EVOH/urethane barrier materials provide good resistance
to yellow dye migration and can provide sufficient intercoat
adhesion without added tie coats. The added crosslinking of the
barrier coat material in this instance also can improve certain
mechanical properties such as tensile strength, but generally, film
toughness and handling are improved more by the thermoplastic form
of the EVOH/urethane barrier material.
[0073] Polymeric materials other than urethanes may be used to form
the modified EVOH barrier layer. Such polymeric materials generally
include polyester, ethylene vinyl acetate copolymer (EVA), and
acrylic resinous materials. The modifying polymeric materials can
be blended with the EVOH to improve certain attributes such as film
toughness or intercoat adhesion. These other polymeric materials
can be dispersed in the EVOH and form a stable emulsion having
barrier properties in dry film form. The barrier properties, as
mentioned, may be improved by modifying the EVOH with a migratory
polymeric material that may improve interlayer adhesion.
[0074] The EVOH barrier layer retards color migration in two ways.
Because of its polar nature, the EVOH does not act to compatibilize
or solublize yellow azo-type colorants. The EVOH also is
crystalline and so it forms a network that does not allow the
yellow azo-type colorant to migrate through the barrier.
[0075] The barrier layer is applied at a sufficiently low coat
weight to produce a barrier coat having a dry film thickness
sufficiently thin so as to not add significant thickness to the
decorative portion (excluding the release liner) of the multi-layer
laminate. In one embodiment, the wall film with the barrier layer
of this invention has a total film thickness (excluding the matte
release liner) of less than about 1.9 mils. Film thickness of the
barrier layer is preferably not more than about ten percent (10%)
of the total thickness of the decorative portion of the film.
[0076] The barrier layer is resistant to softening at elevated
temperatures, and preferably has a glass transition temperature in
excess of 50.degree. C. In one embodiment, the barrier layer has a
T.sub.g greater than about 58.degree. C.
[0077] The barrier layer has been described generally in its use as
a discrete layer between the pigmented base coat layer and the PSA
layer. In alternative forms of the invention, the barrier material
as described herein may be incorporated into one or more of the
other layers of the wall film. For instance, the barrier material
may be incorporated into a color layer to provide the barrier
properties and other attributes of the barrier layer as described
herein.
[0078] Matte Release Liner
[0079] The release liner may comprise a polymeric film, and
including polyolefin, polyester, and combinations thereof. The
release liner preferably may be formed from a flexible, foldable,
heat-resistant, substantially inelastic, self-supporting temporary
carrier film or casting sheet as is known in the art of dry paint
transfer films. The release liner is preferably an oriented
polyester film such as polyethylene terephthalate (PET) available
as Mylar, a trademark of DuPont, or Hoechst Celanese Hostaphan 2000
polyester film, for example.
[0080] The release liner provides structural integrity to the wall
film until the liner is removed upon application of the wall film
to a substrate surface.
[0081] The matte release coat layer may comprise any of the above
identified binders or resins which provide a level of tack between
the release coat layer and the decorative dry paint layer. The tack
level is sufficient to prevent separation of the release coat layer
from the adhered dry paint layer during the process of forming the
wall film and during normal handling, including forming the wall
film in its self-wound orientation, unwinding it, and applying it
to the substrate surface. The matte release coat also continues to
have sufficient release properties to facilitate separation from
adhered dry paint layer after applying the wall film to the
substrate.
[0082] The matte release coating composition is a thermosetting
resinous material which, when exposed to heat for drying it, also
crosslinks and permanently bonds to the release liner. In one
embodiment, the matte release coat formulation includes a primary
crosslinking resin such as a melamine resin that controls
crosslinking and produces adhesion to the polyester carrier film. A
presently preferred crosslinking resin is hexamethoxy methyl resin
such as Cymel 303. A suitable primary functional resin is a vinyl
resin such as a medium molecular weight vinyl chloride-vinyl
acetate resin known as VAGH.
[0083] The matte release coat can include a secondary functional
resin which can be an acrylic-modified alkyd resin such as Chempol
13 1501 or Lankyd 13-1245. The matte release coat further includes
a catalyst for accelerating crosslinking.
[0084] The resinous components of the matte release coat
composition are combined with a primary resin solvent, such as
methyl isobutyl ketone (MibK) and a secondary resin solvent, such
as isopropyl alcohol.
[0085] The matte release coat is prepared by dissolving the primary
functional resin in the primary and secondary resin solvents by
mixing and then adding the secondary functional resin and primary
matting agent, preferably a filler comprising a fine particulate
inert inorganic material, such as aluminum silicate, or talc, or a
fine particulate organic filler material. In one embodiment of the
matte release coat, the ratio of particulates to resin (or binder)
is from about 0.7:1 to about 1.1 to 1.
[0086] In use, the matte release layer dries and crosslinks to form
a chemical matte coating on the carrier. The gloss of the matte
surface is controlled by the amount and particle size of the
filler. The fine particles project through the dried exterior
surface of the matte release coat, forming a surface with a
microroughness that transfers a replicated microroughness to the
exposed surface of the dry paint layer.
[0087] In one embodiment, a matte release coat formulation useful
for this invention contains no significant amount of a
silicone-based release material and/or a wax-based component. Such
materials may be useful in providing release properties at high
temperatures; but the matte release coat of this invention, in one
embodiment, comprises a formulation that, in the absence of a
silicone-based release material or a wax-based component, provides
a useful combination of room temperature release, adherence of the
release liner to the dry paint layer, and transfer of the matte
surface to the exposed surface of the dry paint layer.
[0088] The relative proportions of the components contained in the
matte release coat and the related processing conditions for making
the release coat and applying it to the release liner are described
in further detail in U.S. application Ser. No. 10/799,528, referred
to above.
[0089] The gloss transferred to the outer surface of the dry paint
layer can be controlled by a combination of release coat
formulations and the composition of the outer surface layer of dry
paint in contact with the release coat. In one embodiment, an
85.degree. gloss of less than about 40 gloss units can be
transferred to dry paint films having a monocoat or base coat/clear
coat finish comprised of urethane, acrylic and/or vinyl resinous
paint layers.
[0090] The adhesive release coat layer 28 on the opposite side of
the release liner may comprise any release coating composition
known in the art. Silicone release coating compositions may be
used.
[0091] Processing and Use of the Wall Film
[0092] The wall film illustrated in FIG. 1 may be made by applying
the adhesive release coat to the release liner and then drying and
curing it. The dry coat weight of the adhesive release coat layer
may be from about 0.1 to about 1.0 gram per square meter (gsm), and
in one embodiment, from about 0.25 to about 0.35 gsm. The matte
release coat is then applied to the opposite side of the release
liner and then dried or cured. The dry coat weight of the matte
release coat may be from about 2.5 to about 6.5 gsm, and in one
embodiment, from about 4.5 to about 5.5 gsm. The transparent outer
clear coat is applied to the matte release coat and then dried or
cured prior to application of the pigmented dry paint film layer.
The coat weight for the clear coat may be from about 1 to about 5
gsm, and in one embodiment, about 2.5 to about 3.5 gsm. The liquid
paint composition for forming the pigmented dry paint layer is then
applied to the clear coat layer and then dried or cured. The coat
weight for the dry paint layer may range from about 20 to about 60
gsm, and in one embodiment about 30 to about 40 gsm. The barrier
coat is then applied to the dry paint layer at a coat weight
preferably from about 2.4 gsm to about 6.5 gsm. After the barrier
coat is dried, the pressure-sensitive adhesive layer is applied to
the dry barrier coat and then dried or cured. The adhesive layer
may be applied using coating techniques or transfer lamination. The
coat weight of the adhesive layer may range from about 10 to about
30 gsm, and in one embodiment about 11 to about 17 gsm. The dry
paint transfer laminate 20 may then be wound into roll form as
illustrated in FIG. 2.
[0093] The wall film 20 may be used by unrolling it from the roll
illustrated in FIG. 2, and simultaneously applying the wall film to
the substrate surface to be covered. The substrate may comprise any
flat surface. The flat surface may comprise wall board, plastic
sheet, metal sheet, composites, and the like. The substrate may
comprise an interior (i.e., indoor) wall surface or an exterior
(i.e., outdoor) surface. The wall film may be applied to a painted
wall surface having various surface finishes, such as flat,
eggshell, satin, semi-gloss and high gloss. The wall film is placed
over the substrate with the adhesive layer in contact with the
substrate. The wall film is particularly suited for applying to a
wall under room temperature conditions. Pressure is applied, with
repositioning if necessary, until the wall film is adhered to the
surface. The release liner is then peeled off the front face of the
decorative paint layer, leaving the dry paint layer adhered to the
substrate by the adhesive layer. The dry paint layer can be
smoothed down on the wall by applied pressure after the release
liner is removed.
[0094] The release properties of the wall film are controlled by a
differential release system in which the release force required to
separate the matte release coat from the dry paint layer (which may
comprise the transparent layer, the color layer, and/or decorative
print coats) is greater than the release force required to separate
the adhesive release coat layer from the pressure-sensitive
adhesive layer. The adhesive force to the substrate is greater than
the force to separate the release liner from the dry paint. The
adhesive release forces and unwind release forces of the
differential release system are described in greater detail in
application Ser. No. 10/779,528, referred to above.
EXAMPLE 1
[0095] A PET liner is coated on one side with a silicone release
coating corresponding to the adhesive release coat layer described
above. The thickness of the silicone coated liner is 0.92 mil and
comprises Mitsubishi 92 gauge SLK.
[0096] The matte release coat is applied to the other side of the
release liner using gravure at a coat weight of 4.5 to 5.5 gsm. The
formulation for the matte release coat is as follows (with all
numerical values in parts by weight):
1 Component Parts Methyl isobutyl ketone (MibK) 53.47 Isopropanol
6.49 Lankyd 13-1245 (product of Akzo 7.21 Chemical, an acrylic
modified alkyd) VAGH (product of Union Carbide, hydroxy 8.72
modified polyvinyl chloride/polyvinyl acetate copolymer EFKA 5055
(a carboxylic acid ester 1.10 dispersing agent) Microtalc MP 15-38
(Barretts Minerals) 23.02 Cymel 303 (Cytec melamine resin) 7.45 Byk
451 (Byk Chemie blocked acid catalyst) 3.50
[0097] In preparing the release coat material the base materials
(VAGH, alkyd and talc) are compounded in a 100 part formula. The
Cymel 303 and Byk 451 are later blended and after the materials are
delivered to the coater the two solutions are blended together. The
matte release coat is dried and cured using forced air at a
temperature of 149.degree. C.
[0098] The matte release coat comprises as its crosslinking resin
the melamine (hexamethoxy methyl) resin Cymel 303. The hydroxyl
modified polyvinyl chloride/polyvinyl acetate copolymers (VAGH)
comprise the primary functional resin and the acrylic modified
alkyd comprises a secondary functional resin. The primary
crosslinking resin controls crosslinking and bonds to the polyester
carrier film. The secondary functional resin modifies release of
the dry paint layer (top coat) from the matte release coat. The
blocked acid catalyst accelerates the crosslinking process and the
talc filler particles control the degree of microroughness of the
dry matte release coat.
[0099] A transparent clear coat layer is applied to the matte
release coat using gravure at a coat weight of 2.6 to 3.0 gsm and
dried using forced hot air at a temperature of 165.degree. C. The
dry film thickness is 0.09-0.10 mil. The clear coat consists
essentially of a thermoplastic acrylic resinous material,
preferably polymethyl methacrylate. The formulation for the
transparent top coat layer (with all numerical values in parts by
weight) is as follows:
2 Component Parts Methyl ethyl ketone (MEK) 40 MibK 41 Elvacite
2042 (product of Lucite 19 International, polyethyl
methacrylate)
[0100] One or more decorative print coats having printing ink
formulations similar to those described in application Ser. No.
10/779,528 are printed over the transparent top coat layer and
dried.
[0101] The following paint coat composition comprises a plasticized
vinyl-based pigmented color coat having an epoxy stabilizer. The
paint coat is coated over the decorative print layers, using roll
coating at a coat weight of 33.0 to 36.0 gsm and dried in hot air
at a temperature of 105.degree. C. to form a color coat layer. The
dry film thickness is 0.65 to 0.73 mil. In the following table all
numerical values are in parts by weight:
3 Component Parts NiPar 820 (product of Angus Chemical, 15.98 a
blend of 80% nitro propane and 20% nitro ethane) Xylene 23.95
Cyclohexanone 7.71 VYHH (product of Union Carbide, a vinyl 12.76
chloride/vinyl acetate copolymer) Edenol 9790 (product of Cognic, a
6.38 polyester plasticizer) Stanclere T-883 (product of Adchross
0.06 Chemical, a tin heat stabilizer) EPON 828 (epoxy resin product
of Shell) 0.26 DV 39600 (Gibraltar TiO.sub.2 white 32.12 pigment
dispersion) DV 396420 (Gibraltar carbon black 0.23 pigment
dispersion) DV 36500 (Gibraltar red pigment 0.16 dispersion) DV
34130 (Gibraltar phthalo blue 0.39 pigment dispersion)
[0102] A barrier coat is prepared by charging a solvent mixture
containing 85 gms of water and 85 gms of isopropyl alcohol in a
reactor equipped with a mixer and reflux condenser. While mixing,
30 gms Soarnol D-2908 EVOH in pellet form are added to the solvent
mixture. The mixture is heated to a temperature of about 80.degree.
C. and held for about three to four hours until it becomes a clear
solution. The solution is then cooled to room temperature, say
about 25.degree. C., and followed by post-adding 21.4 gms of
Sancure 899 polyurethane in liquid form for slowly blending with
the EVOH under agitation. This produces a two-phase thermoplastic
liquid emulsion in which the polyurethane resin is dispersed in the
aqueous/isopropynol solution at a solids ratio of about 20 parts
urethane to 80 parts EVOH by weight. The coating is applied to the
pigmented base coat by coating and then oven drying at 70.degree.
C. for about five minutes. The coating is preferably applied by die
coating techniques to produce a dry film thickness of about 2.5 to
about 4.5 microns.
[0103] A pigmented pressure sensitive adhesive layer is then
applied to a carrier at a coat weight of 13 to 16 gsm. The dry film
thickness of the PSA is from about 0.45 to 0.55 mil. The PSA is
then applied to the barrier coat by transfer lamination. The PSA is
available from Avery Dennison Corporation under product no. S-3526
and the formulation for the PSA is as follows (with numerical
values in parts by weight):
4 Component Parts S-3506 (product of Avery Dennison, 96.0
Performance Polymers, a cross-linked copolymer emulsion of butyl
acrylate and 2-ethyl hexyl acrylate) UCD 110GE (white TiO.sub.2
pigment 3.7 dispersion from Rohm and Haas) UCD 1507E (carbon black
pigment 0.3 dispersion from Rohm and Haas)
[0104] The dry film thickness of the decorative laminate of this
example is within a preferred range of about 1.30 to about 1.60
mil. In the described example, the dry film thickness of the
combined top coat, print coats, color coat, barrier coat and PSA is
from 1.35 to 1.51 mil.
EXAMPLE 2
[0105] An alternative embodiment of the matte release coat
comprises the following formulation in which a dispersing agent is
omitted and the catalyst is changed to an unblocked catalyst. (All
numerical values are in parts by weight.)
5 Component Parts MibK 50.54 Isopropanol 7.84 Lankyd 13-1245 8.93
VAGH 10.68 Microtale MP 15-38 22.00 Cymel 303 6.80 Cycat 4040
(paratoluene sulfonic acid) 2.00
[0106] Adjustments may be made to release properties and gloss in
this release coat formulation by optionally adding the following
intermediate formulations in which the matte intermediate is used
to adjust gloss down and the vehicle intermediate is used to adjust
gloss upward.
6 Matte Intermediate Component Parts MibK 28.05 Lankyd 13-1245 4.05
VAGH 4.90 Dispersing agent 18.00 Microtalc MP 15-38 45.00
[0107] The dispersing agent comprises 10 parts by weight EFKA 5055
and 90 parts by weight MibK.
7 Vehicle Intermediate Component Parts MibK 64.83 Isopropanol 13.00
Lankyd 13-1245 10.03 VAGH 12.14
EXAMPLE 3
[0108] Test panels were prepared and tested for color shift,
comparing color shift for: (1) wall films similar to Example 1
containing a barrier coat and (2) similar wall films in the absence
of a barrier coat. The test films were applied to a medium yellow
(Hansa Yellow 10G and Dalamar Yellow PY74) painted surface and
subjected to accelerated aging. The test films were measured for
discoloration (color shift) caused by migration of azo-type color
constituents that passed from the painted surface through the PSA
layer to the color layer of the test sample. The test panels were
prepared using a dry paint color layer containing a plasticized
vinyl-based paint layer containing a dispersed white pigment. The
S-3506 PSA was applied to the color layer. The test panels included
a white wall film with 2.5 gsm EVOH/urethane barrier, a white wall
film with 6.5 gsm EVOH/urethane barrier, and a white wall film with
no barrier layer. The modified EVOH barrier layers were
thermoplastic. No tie layers were used for the barrier coats. The
EVOH/urethane ratio was 80/20. The medium yellow painted substrate
was prepared using Behr 1300 deep base (5 ounces medium yellow per
gallon base) applied at 7.5 mils wet coating to 3 mil polyester.
The paint coat was allowed to dry for three hours minimum at room
temperature then force air dried for five minutes at 250.degree. F.
C.I.E. test procedures were used to measure .DELTA.b* color change
at pre-set time intervals on the test panels exposed to different
elevated test temperatures and at room temperature. The instrument
used in the tests was Macbeth Color-Eye 7000; illuminant and
geometry: D65, 10.degree. observer and specular excluded. These
tests yielded the following results:
[0109] C.I.E. Delta b* Color Change Per Time at Temperature
[0110] White wall film, 2.5 gsm EVOH/PU barrier
8 Hrs@Temp 40 C. 60 C. 70 C. 80 C. 90 C. RT 0 0 0 0 0 0 0 27 0 0.05
0.02 0.22 118 0.01 0.08 0.07 0.50 2.30 285 0.02 0.08 0.07 0.50 2.30
454 0.01 0.10 0.29 1.15 2.93 622 0.04 0.21 0.35 1.19 3.04 790 0.03
0.23 0.43 1.18 2.72 0.01 957 0.01 0.27 0.51 1.29 3.04
[0111] White wall film, 6.5 gsm EVOH/PU barrier
9 Hrs@Temp 40 C. 60 C. 70 C. 80 C. 90 C. RT 0 0 0 0 0 0 0 27 0 0.03
0 0 118 0.02 0 0 0 0 285 0.01 0 0.05 0 0.27 454 0.01 0 0.06 0.53
0.39 622 0.01 0.02 0.19 0.44 0.33 790 0.02 0 0.13 0.10 0.58 0 957
0.01 0.02 0.19 0.24 0.30
[0112] White wall film, no barrier coating
10 Hrs@Temp 40 C. 60 C. 70 C. 80 C. 90 C. RT 0 0 0 0 0 0 0 27 0.91
6.69 10.6 18.01 118 2.95 7.71 11.78 18.02 21.16 285 6.67 8.19 12.15
17.87 20.93 454 3.89 8.35 12.31 17.24 19.88 622 3.04 8.50 12.30
15.21 16.75 790 3.08 8.54 12.35 14.72 14.08 0.34 957 3.10 8.65
12.37 14.58 14.09
[0113] These test data show that the EVOH-based barrier coats
produced resistance to color shift well within the 0.4 .DELTA.b*
standard for up to 1000 hours accelerated color shift testing.
Intercoat adhesion also was good without added tie coats.
EXAMPLE 4
[0114] Comparative tests were conducted on various test panels to
measure time-related color change. The test panels are tested using
a quick test method which starts with a wall film construction
having a matte release layer, top coat and a white pigmented base
coat. The film is placed in a vacuum holder and the barrier layer
under test is coated on the base coat. The barrier coated film is
dried at 70.degree. C. oven temperature for five minutes. The
barrier coat is laminated with a S-3506 PSA having a PET liner. The
PET liner is then removed and a yellow dye coated PET film is
laminated to the PSA. The finished construction is placed in an
80.degree. C. oven for about twelve hours and color density on the
white film is then measured by a color density instrument such as
Tobias 1Q 150 to determine discoloration. The following test
measurements illustrate color density for a yellow dye test at
90.degree. C. for various time intervals. The test panels
(identified as A through G) are shown in the following table:
[0115] Yellow Dye Test (90.degree. C.); Yellow Color Density
11 Hours A B C D E F G 1 0 0 0 0 0 0.01 0.03 2 0 0 0 0 0.01 0.02
0.05 3 0 0 0 0 0.01 0.04 0.06 4 0 0 0 0 0.02 0.05 0.08 5.5 0 0 0 0
0.02 0.06 0.08 8.5 0 0 0 0 0.03 0.08 0.1 24 0 0 0 0 48 0 0 0 0 72
0-0.01 0 0-0.1 0.01 144 0-.03 0 0-0.04 0.03 168 192 0.13 0.16 0.16
216 0-0.05 0 0-0.04 0.03 264 0.04 0.14 0.16 0.16 312 0.05 0.01
0.060 Coat Wt. 2.4 5.2 2.2 2 3 2.8 0 gsm A: 80 EVOH/20 PU;
thermoplastic; no tie coats B: 80 EVOH/20 PU; crosslinked with 3%
Cymel, 10% Polyaziridine; tie coats used on opposite sides C: 80
EVOH/20 PU; crosslinked with 5% Polyaziridine D: EVOH only E: 70
PU/30 PVA F: Acrylic only and tie coat G: No barrier
EXAMPLE 5
[0116] Lab test samples for measuring color density were cast and
oven dried at 70.degree. C. for five minutes. The wall films under
test were similar to those described in the previous examples. In
one series of tests, the barrier coat was applied by reverse comma
coating techniques. The barrier coats consisted of 80% EVOH/20% PU,
with 50 water/50 IPA solvent. In addition to a control sample
having no barrier layer, yellow dye color density tests at
90.degree. C. were conducted for samples having a variation of coat
weights between about 2.2 to about 7.2 gsm, for barrier coats with
the EVOH component having different levels of crosslinking, and for
barrier coats having thermoplastic properties (no crosslinking).
Test samples A, B and C in Example 3 show dye test results for
these lab samples. Separate lab tests for similar barrier materials
were conducted by die coating techniques coated at 20 fpm and 40
fpm with zone temperatures at 165.degree. F., 200.degree. F., and
225.degree. F. Lab tests also were conducted by reverse gravure
coat techniques at 2 fpm, zone temperatures of 165.degree. F.,
200.degree. F., and 225.degree. F. with a solvent system of 50
water/34 IPA/16 n-butanol. These lab tests are summarized as
follows:
[0117] (1) Addition of the barrier coat produces greatly improved
resistance to color migration of the yellow pigments. Without a
barrier, the tests showed that it takes only two hours at
90.degree. C. to see yellowing to a color density of 0.02.
Long-term resistance to yellow pigment migration also is improved
when compared with barrier layers made of acrylic resin.
[0118] (2) Die coating techniques produced good film processing
conditions. The addition of the n-butanol to replace some IPA
improves processing when reverse gravure techniques were used.
Gravure coating generally provides good film forming due to its
thin layer.
[0119] (3) The higher the coat weight, the better the barrier
properties on stopping yellow dye migration. However, higher coat
weights can result in poor barrier film quality. A dry film coating
thickness of the barrier from about 2.5 to about 4.5 microns
produces good film quality High coat weights with lower solvent
solutions can cause film shrinkage or blistering during drying.
Better results are achieved with high coat weights and increased
solids.
[0120] Tests were conducted on the same group of test panels to
measure the effect of barrier layers on mechanical properties of
the wall film. Comparative tests were conducted on a control sample
(no barrier), and for 80% EVOH/20% PU films having a coat weight
variation from 2.2 to 7.2 gsm, for films having a thermoplastic
EVOH/PU barrier, and for EVOH/PU films having various levels of
crosslinking. The test results generally showed improvements in
stress (Young's modulus) and strain measurements for both films at
various coat weights compared to lower measurements for the control
film. One exception was a thermoplastic EVOH/PU film having a high
coat weight (7.2 gsm). This test panel had a low stress measurement
and excessively high elongation. Films having crosslinked EVOH/PU
barrier coats produced good barrier properties, but film
flexibility required for film handling and resistance to tearing
was generally improved with films having thermoplastic EVOH/PU
barrier layers which had better combinations of elongation and
tensile strength (film toughness). In one embodiment good film
flexibility and handling qualities are produced with films having
an elongation to break of greater than 50%.
EXAMPLE 6
[0121] Tests were conducted on wall films similar to those
described above, with barrier layers having various EVOH/urethane
compositions, to determine surface energy and film performance,
with the following results:
12 EVOH/PU Blend Surface Energy and Performance Surface Energy mN/m
Water Soak Barrier EVOH PU Dispersion Polar Total Adhesion Property
100 0 29.7 5.2 34.9 Poor Good 95 5 21.9 17.9 39.8 Poor Good 90 10
22.5 20.3 42.8 Fair Good 85 15 22.5 19.7 42.2 Good Good 80 20 20.7
24.9 45.6 Good Good 0 100 31.5 4.5 36 Good Poor
[0122] These data show that during the coating process, the
polyurethane emulsion tends to migrate to the surface, improving
surface energy which tends to improve adhesion to the color layer
and adhesion to the PSA layer. Film performance from the EVOH/PU
barrier is improved generally with polyurethane contents greater
than about 15%, and more specifically from about 15% to about 40%.
Test data have shown best overall performance at a polyurethane
content of approximately 20%.
EXAMPLE 7
[0123] Tests were conducted on wall film constructions with and
without barrier coats. These tests measured peel values for the PSA
layers, for films with a barrier layer and without a barrier layer.
The test samples included 80% EVOH/20% PU barrier layers and an
Avery Dennison PSA identified as AE-3506. Pigment to volume
concentration (PVC) in the color coats refers to pigment volume
with respect to total volume of non-volatile components in the
formulation. Test samples were aged at room temperature and at
140.degree. F. The peel tests were conducted on both stainless
steel and on gray flat painted drywall. Peel tests were at
90.degree. peel using a 10 lb. roller and 15 min. dwell time. In
the test results to follow, peel units are in gm/in.
[0124] Barrier Coat Stability
13 Stainless Steel Wall Film Pigment/Vol Room Temp. Aged at
140.degree. F. Barrier Concentration % 1 week 1 week No 24.0 432
498 Yes 24.0 500 586 No 16.0 400 445 Yes 16.0 400 500 No 9.0 377
355 Yes 9.0 595 609
[0125]
14 Flat Drywall Pigment/ Vol Wall Concen- Room Temp. Aged at
140.degree. F. Film tration 1 2 1 2 3 4 Barrier % week weeks week
weeks weeks weeks No 24.0 368 364 259 239 218 245 Yes 24.0 341 323
286 355 332 318 No 16.0 350 332 245 214 186 264 Yes 16.0 332 418
368 408 373 323 No 9.0 345 368 204 133 164 114 Yes 9.0 354 359 327
350 359 336
[0126] These data are better illustrated in the graph shown in FIG.
4.
[0127] These test data generally show that addition of the wall
film barrier provides consistently higher peel values compared with
test samples having no barrier. The barrier appears to be effective
in preventing migration of contaminants from the color layer to the
adhesive layer. More specifically, the barrier appears to stop
migration of constituents such as plasticizers and heat stabilizers
from the color layer into the PSA layer, leaving the PSA layer more
effective in its adhesive properties.
EXAMPLE 8
[0128] Lab tests were conducted to determine whether barrier
properties and other mechanical properties of the decorative film
can be maintained with EVOH barrier coats modified with polymeric
resin additives other than the aliphatic polyurethane (Sancure 899)
described previously. The following tests were conducted with a
solid blue color coat similar to Example 1 (with a 24% pigment
volume concentration) as the baseweb and 80% EVOH/20% polymer as
the barrier coat. The control film was the same baseweb (clear
coat, color coat, PSA) without the barrier coat. The thermoplastic
forms of the barrier coats were tested.
15 Barrier Yellow Dye 810 Tape Tensile/elongation Material Type
Polymer Migration Test % Elongation Baseweb Control poor 15
Aliphalic Sancure good good 81 polyester 899 Aromatic Sancure good
good 73 polyester 1511 Acrylic Neocryl good good 62 XK-90 EVA
AirFlex good good 87 920
[0129] The 810 tape test is a single diagnostic adhesion test using
about 4 inches of 3M 810 tape, pressing to the barrier coat and
peeling quickly. If nothing peels off, adhesion is considered
good.
[0130] These test results can be summarized as follows:
[0131] (1) Emulsion types of EVA, acrylic or aromatic polyester
polyurethane can be used as EVOH barrier modifying materials in
addition to the alphatic urethane.
[0132] (2) No yellow dye migration was observed (using the quick
yellow dye test) after 4 days at 90.degree. C.
[0133] (3) The barrier coat can dramatically increase the
elongation/tensile (flexibility) of the baseweb at coat weights of
about 5 to 6 gsm.
[0134] (4) All materials tested gave good adhesion to the color
coat.
[0135] Tests on film tensile strength and Young's modulus show that
at 16% pigment volume concentration, all variations of the barrier
film produced tougher films when compared with the same baseweb
having no barrier coat.
[0136] The present invention has been described with respect to
multilayer laminates used as a wall film for interior architectural
applications, but the laminate also is useful in other applications
as well. These would include exterior architectural applications
such as siding panels and wall surfaces; outdoor decorative items
and signs; interior automotive decorative and functional uses such
as dashboards and panels; and exterior automotive uses including
automotive body parts, trim parts and panels.
* * * * *