U.S. patent application number 10/071561 was filed with the patent office on 2003-02-06 for edge treatments for coated substrates.
This patent application is currently assigned to Cardinal Glass Industries, Inc.. Invention is credited to Hartig, Klaus, O'Shaughnessy, Roger D..
Application Number | 20030024180 10/071561 |
Document ID | / |
Family ID | 27401973 |
Filed Date | 2003-02-06 |
United States Patent
Application |
20030024180 |
Kind Code |
A1 |
Hartig, Klaus ; et
al. |
February 6, 2003 |
Edge treatments for coated substrates
Abstract
The invention provides a substrate (e.g., a glass pane) having
generally opposed first and second major surfaces. At least one of
these major surfaces bears a functional coating and has a
peripheral region that is substantially free of the functional
coating. Another embodiment provides a multiple-pane insulating
glass unit comprising two spaced-apart panes and a spacer joining
confronting, inner peripheral surfaces of the panes. At least one
of the panes has a coated outer surface. This coated outer surface
has a peripheral region that is substantially free of the coating.
The invention also provides methods for treating a coated substrate
that has generally opposed first and second major surfaces each
bearing a functional coating. The coating is substantially removed
from a peripheral region of the first major surface. Likewise, the
coating is substantially removed from a peripheral region of the
second major surface. A further embodiment provides a barrier layer
that prevents contact between glazing compound and an exterior
coating. Durable glazing compounds are provided in yet another
embodiment.
Inventors: |
Hartig, Klaus; (Avcoa,
WI) ; O'Shaughnessy, Roger D.; (Eden Prairie,
MN) |
Correspondence
Address: |
FREDRIKSON & BYRON, P.A.
4000 PILLSBURY CENTER
200 SOUTH SIXTH STREET
MINNEAPOLIS
MN
55402
US
|
Assignee: |
Cardinal Glass Industries,
Inc.
Eden Prairie
MN
|
Family ID: |
27401973 |
Appl. No.: |
10/071561 |
Filed: |
February 8, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60267923 |
Feb 8, 2001 |
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60267507 |
Feb 8, 2001 |
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60274363 |
Mar 8, 2001 |
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Current U.S.
Class: |
52/204.5 ;
52/204.593; 52/204.6 |
Current CPC
Class: |
C03C 17/002 20130101;
C03C 17/3417 20130101; B24B 7/242 20130101; E06B 3/56 20130101;
C03C 17/256 20130101; B24B 9/102 20130101; C03C 2218/365 20130101;
B24B 7/26 20130101; E06B 3/6621 20130101; C03C 2217/78 20130101;
C03C 17/366 20130101; B24B 7/17 20130101; C03C 17/36 20130101; E06B
3/6715 20130101; C03C 17/00 20130101; E06B 3/5427 20130101; C03C
19/00 20130101; C03C 2218/328 20130101; C03C 2217/71 20130101; E06B
3/66342 20130101 |
Class at
Publication: |
52/204.5 ;
52/204.6; 52/204.593 |
International
Class: |
E06B 003/00; E06B
003/68 |
Claims
1. A transparent pane having generally-opposed first and second
major surfaces, each major surface bearing a functional coating and
having a peripheral region that is substantially free of the
functional coating.
2. The transparent pane of claim 1 wherein the functional coating
on one of said major surfaces is an active coating.
3. The transparent pane of claim 2 wherein the active coating is a
photocatalytic coating.
4. The transparent pane of claim 3 wherein the photocatalytic
coating comprises titanium oxide.
5. The transparent pane of claim 2 wherein the functional coating
on the other major surface is a low-emissivity coating.
6. The transparent pane of claim 1 wherein the functional coating
on each major surface is an active coating.
7. The transparent pane of claim 1 wherein said coating-free
peripheral region on each major surface extends a predetermined
distance inwardly from an edge of the substrate.
8. The transparent pane of claim 7 wherein said predetermined
distance is less than about one inch.
9. The transparent pane of claim 8 wherein said predetermined
distance is about 1/2 inch.
10. A transparent pane having generally-opposed first and second
major surfaces, at least one of said major surfaces bearing an
active coating and having a peripheral region that is substantially
free of the active coating.
11. The transparent pane of claim 10 wherein the active coating is
a photocatalytic coating.
12. A multiple-pane insulating glass unit comprising two
spaced-apart panes and a spacer joining confronting, inner
peripheral surfaces of the panes, the spacer and the confronting
surfaces of the panes together defining a between-pane space, at
least one of the panes having an outer surface bearing a functional
coating, said outer surface having a peripheral region that is
substantially free of the functional coating.
13. The insulating glass unit of claim 12 wherein the functional
coating is an active coating.
14. The insulating glass unit of claim 13 wherein the active
coating is a photocatalytic coating.
15. The insulating glass unit of claim 14 wherein the
photocatalytic coating comprises titanium oxide.
16. The insulating glass unit of claim 12 wherein at least one of
the panes has a coated inner surface bearing a low-emissivity
coating.
17. The insulating glass unit of claim 16 wherein said coated inner
surface has a peripheral region that is substantially free of said
low-emissivity coating.
18. The insulating glass unit of claim 12 further comprising a
frame in which at least one edge region of the insulating glass
unit is received, wherein a bead of glazing compound is disposed
between a mounting surface of the frame and said coating-free
peripheral region of the insulating glass unit.
19. The insulating glass unit of claim 18 wherein the functional
coating is photocatalytic and the glazing compound comprises an
organic material.
20. The insulating glass unit of claim 19 wherein the glazing
compound provides a substantially water-proof seal between the
mounting surface of the frame and said coating-free peripheral
region of the insulating glass unit.
21. A method of treating a coated substrate, the method comprising:
a) providing a transparent pane having generally-opposed first and
second major surfaces, each major surface bearing a functional
coating; b) removing substantially all of the functional coating
from a peripheral region of the first major surface; and c)
removing substantially all of the functional coating from a
peripheral region of the second major surface.
22. The method of claim 21 wherein the functional coating is
removed from both major surfaces of the pane substantially
simultaneously.
23. The method of claim 21 wherein the functional coating is
removed from both major surfaces of the pane by grinding.
24. The method of claim 23 wherein the functional coating is
removed from said first major surface using a first grinder, and
the functional coating is removed from said second major surface
using a second grinder.
25. The method of claim 24 wherein the pane is positioned between
the first and second grinders while simultaneously operating said
grinders.
26. A glazing assembly comprising: a) a transparent pane having
generally-opposed first and second major surfaces, at least one of
said major surfaces bearing an active coating; b) a frame in which
at least one edge of the pane is received, the frame having a
mounting surface against which said coated pane surface is
retained; and c) a bead of glazing compound disposed between the
mounting surface of the frame and a peripheral region of said
coated pane surface, the glazing compound being shielded from
direct contact with the active coating by a barrier layer provided
between said coated pane surface and the glazing compound.
27. The glazing assembly of claim 26 wherein the glazing compound
comprises a material to which the active coating is
degenerative.
28. The glazing assembly of claim 27 wherein the active coating is
photocatalytic and the glazing compound comprises an organic
material.
29. The glazing assembly of claim 26 wherein the barrier layer
comprises a material that is durable to the active coating.
30. The glazing assembly of claim 29 wherein the active coating is
photocatalytic and the barrier layer comprises an inorganic
material.
31. The glazing assembly of claim 26 wherein the glazing compound
provides a substantially water-proof seal between the mounting
surface of the frame and the coated pane surface.
32. The glazing assembly of claim 26 wherein the substrate is part
of a multiple-pane insulating glass unit mounted in the frame.
33. A glazing assembly comprising: a) a transparent pane having
generally-opposed first and second major surfaces, at least one of
said major surfaces bearing an active coating; b) a frame in which
at least one edge of the pane is received, the frame having a
mounting surface against which said coated pane surface is
retained; and c) a bead of glazing compound disposed between the
mounting surface of the frame and a peripheral region of said
coated pane surface, the glazing compound being in direct contact
with the active coating and comprising a material that is durable
to the active coating.
34. The glazing assembly of claim 33 wherein the active coating is
photocatalytic and the glazing compound comprises an inorganic
material.
35. The glazing assembly of claim 33 wherein the glazing compound
provides a substantially water-proof seal between the mounting
surface of the frame and the coated pane surface.
36. The glazing assembly of claim 33 wherein the transparent pane
is part of a multiple-pane insulating glass unit mounted in the
frame.
37. A frameless glazing assembly comprising: a) a transparent pane
having generally-opposed first and second major surfaces, at least
one of said major surfaces bearing an active coating and having one
or more surface regions that are each substantially free of the
active coating; b) one or more mounts bounding a glazing opening in
which the transparent pane is mounted, each mount defining a
mounting surface against which said coated pane surface is
retained; and c) a bead of glazing compound disposed between each
mount surface and a respective one of said coating-free surface
regions.
38. The frameless glazing assembly of claim 37 wherein the active
coating on the transparent pane is a photocatalytic coating.
Description
FIELD OF THE INVENTION
[0001] The present invention provides a substrate bearing at least
one functional coating. Also provided are insulating glass units,
windows, and other glazing assemblies that include a substrate of
this nature. More particularly, this invention provides a substrate
having a coated surface of which a peripheral region is treated for
contact with glazing compound. The invention also provides methods
for treating peripheral regions of coated substrates. Durable
glazing compounds are also provided, as are barrier layers for
shielding glazing compound from functional coating.
BACKGROUND OF THE INVENTION
[0002] Low-emissivity coatings are well known in the present art.
These coatings are characterized by their ability to transmit high
levels of visible light, while minimizing the transmittance of
infrared radiation. Low-emissivity coatings help minimize the
radiative heat transfer through windows and other glazing
assemblies. Thus, during a cold winter, the heat loss from a warm
room to the frigid outdoor environment is minimized. Likewise,
during a warm summer, the heat radiated into a cool room from the
hot outdoor environment is minimized.
[0003] Low-emissivity coatings typically comprise one or more
infrared-reflective metallic layers. These metallic layers are
commonly formed of silver, which is quite vulnerable to chemical
attack. For example, silver is known to corrode when exposed to
oxygen and moisture. When the silver in a low-emissivity coating
corrodes, there is typically an attendant degradation of coating
quality. For example, corrosion of the silver in a low-emissivity
coating may reduce the infrared reflectivity of the coating, hence
jeopardizing its intended function. This corrosion may also
negatively impact the aesthetic appearance of the coated article.
As a result, low-emissivity coatings are typically limited to use
on the inner surfaces of multiple-pane insulating glass units
(i.e., IG units), where these coatings are protected from the
ambient environment.
[0004] Substrates bearing interior low-emissivity coatings are
preferably edge deleted before being incorporated into IG units.
This is perhaps best understood with reference to FIG. 1, which
illustrates the basic structure of a double-glazed IG unit. The IG
unit comprises two panes 10, 10' held in a spaced-apart
relationship by a spacer 101. The confronting, inner surfaces 14,
14' of the panes 10, 10' define between them a sealable
between-pane space 115. As is typical of low-emissivity IG units,
the inner surface of one of the panes bears a low-emissivity
coating 40.
[0005] Low-emissivity coatings are typically less than ideal for
bonding with a spacer. As noted above, these coatings tend to lack
chemical stability. This makes it difficult to durably bond a
spacer to a surface bearing such a coating. For example, when the
infrared-reflective material in a low-emissivity coating corrodes,
it may be difficult to form or maintain a strong bond with the
corroded surface. In FIG. 1, for example, the bond between the
spacer 101 and the inner surface 14 of the first pane 10 would be
jeopardized by corrosion of the low-emissivity coating 40. Thus, to
provide durable bonding of the spacer to the thus coated surface,
it is desirable to remove the low-emissivity coating from the area
of the inner pane surface to which the spacer will be bonded. This
process is referred to as "edge deletion".
[0006] It is known to perform edge deletion of interior
low-emissivity coatings. In this regard, reference is made to U.S.
Pat. Nos. 4,716,686 (Lisec) and 5,934,982 (Vianello et al.), the
entire teachings of each of which are incorporated herein by
reference.
[0007] FIG. 2 illustrates an IG unit wherein edge deletion has been
performed on an interior low-emissivity coating 40. The
low-emissivity coating 40 has been removed from a peripheral region
140 of the inner surface 14 of the first pane 10. This allows the
spacer to be bonded directly to the uncoated surface of the pane.
It also keeps the edges 40E of the low-emissivity coating 40 from
being exposed to the ambient environment. If the edges of a
low-emissivity coating are exposed to the ambient environment (as
in FIG. 1), then corrosion may occur at the edges of the coating,
potentially then spreading inward, such that the bond between the
spacer and the pane is jeopardized. These corrosion problems can be
largely avoided by performing edge deletion of the interior
low-emissivity coatings used in IG units.
[0008] The IG units illustrated in FIGS. 1 and 2 each bear an
exterior coating 20. Exterior coatings typically do not suffer from
the corrosion problems discussed above. Thus, edge deletion has
traditionally not been performed on exterior coatings. However, it
would be advantageous to perform edge deletion of exterior
coatings. For example, consider the manner in which IG units are
typically installed.
[0009] FIG. 3 exemplifies the installation of an IG unit into a
very basic frame 50. The IG unit is retained in a glazing channel
60 of the frame 50. The glazing channel 60 is bounded by three
mounting surfaces of the frame. Specifically, the glazing channel
60 is defined by two confronting mounting surfaces 55 and a base
mounting surface 53. The edge regions of the IG unit are encased by
the confronting mounting surfaces 55. For illustration purposes,
the edges 10E of the panes 10, 10' are shown as being spaced-apart
from the base mounting surface 53. However, there would not
typically be significant space between the installed IG unit and
the base mounting surface 53 (although a gasket and/or glazing
compound may be positioned therebetween).
[0010] Glazing compound (i.e., bedding material) is typically used
to adhere the frame and the IG unit to one another. In FIG. 3, the
glazing compound 70 has been applied between the outer surfaces 12,
12' of both panes 10, 10' and the respective confronting mounting
surfaces 55 of the frame 50. The outer surface 12 of the first pane
10 bears an exterior coating 20 that is not edge deleted. Thus, the
glazing compound 70 adjacent the first pane 10 is bonded directly
to the exterior coating 20.
[0011] Edge deletion of exterior coatings would facilitate reliable
adherence of glazing compound. For example, glazing compound may
bond less durably with certain glass coatings than with glass
itself. Therefore, it would be beneficial to edge delete exterior
coatings of this nature. It would even be beneficial to edge delete
exterior coatings that are capable of being bonded durably and
permanently to glazing compound. For example, even the most
reliable coating method yields a certain percentage of defective
coatings. Defective coatings may peel, or otherwise delaminate,
from the substrates to which they are applied. As defective
coatings would typically not provide good foundations for bonding
with glazing compound, it would be advantageous to edge delete all
types of exterior coatings.
[0012] It would be particularly advantageous to edge delete
photocatalytic coatings. In recent years, a great deal of research
has been performed on coatings that exhibit photoactivity.
Photocatalytic coating technology is founded on the long known
ability of certain materials to absorb radiation and
photocatalytically degrade organic materials such as oil, plant
matter, fats, and greases. The most powerful of these
photocatalytic materials appears to be titanium oxide. However,
other materials are reported to exhibit photoactivity as well.
[0013] Windows and other glazing assemblies would derive great
benefit from photocatalytic coatings. For example, these coatings
may have self-cleaning properties. When organic matter is deposited
on a photocatalytic window coating, the coating may begin to
chemically degrade these organic deposits, thereby having a
cleaning effect on the coated surface. Moreover, to the extent any
residue survives this photocatalysis, the residue may be more
easily removed by washing or, for outdoor applications, by run-off
rainwater.
[0014] One might not expect exterior photocatalytic coatings to
require edge deletion. For example, consider once again the
installation of an IG unit. As shown in FIG. 3, the peripheral
regions of the exterior coating 20 are typically concealed both by
the glazing compound 70 and by the shoulders 57 of the frame 50. As
a result, the peripheral regions of an exterior photocatalytic
coating might not be expected to exhibit significant photoactivity.
Photocatalytic coatings require both moisture and incident
radiation to exhibit photoactivity. In principle, neither one of
these commodity would be readily available at the concealed
peripheral areas of an exterior coating. For example, glazing
compound is intended to seal against water infiltration between the
pane and the frame. Thus, moisture would not be expected to reach
the coating areas sealed beneath the glazing compound. Moreover,
these peripheral coating areas are typically sandwiched between the
shoulders 57 of the frame 50. As a result, these coating areas
would be largely shielded from incident radiation.
[0015] Notwithstanding this concealment of peripheral exterior
coating, moisture and radiation both may reach the peripheral areas
of an exterior photocatalytic coating. For example, glazing
compound may have enough permeability to allow sufficient migration
of moisture to these concealed coating areas to support
photocatalysis. Further, while these peripheral coating areas may
be shielded from direct radiation, multiple reflections within a
pane or IG unit may deliver radiation to these coating areas in
sufficient quantity to generate photoactivity. As a consequence,
photoactivity may occur at the concealed peripheral areas of an
exterior photocatalytic coating. The unfortunate result may be
chemical degradation of nearby glazing compound.
[0016] Degradation of glazing compound may have undesirable
consequences. For example, even the slightest deterioration of
glazing compound may allow water to infiltrate between a monolithic
pane or IG unit and the surrounding frame. This is perhaps best
illustrated with reference to FIG. 3. If water were to permeate the
glazing compound 70 on either side of the IG unit, then the glazing
channel 60 of the frame 50 may accumulate water. This could lead to
corrosion of the underlying frame structure. In severe
circumstances, the bottom of the IG unit may be left sitting in
water, which could contain chemicals from glazing compound,
sealant, paint, and a variety of other sources. Ultimately, this
may cause the edge seal of the IG unit to fail, which would
typically necessitate replacement of the entire IG unit.
[0017] Glazing compound deterioration may have other dire
consequences as well. For example, glazing compound density and
volume may decrease, potentially exacerbating the water
infiltration problem discussed above. In extreme cases, this may
eventually cause a monolithic pane or IG unit to become loose in
its frame. Moreover, depending upon the manner in which a given
pane or IG unit is mounted, glazing compound deterioration may be a
safety hazard. For example, in frameless glazing installations,
panes may be fixed in position primarily by adhesion to glazing
compound. In applications of this nature, deterioration of the
glazing compound could conceivably cause a pane to fall from its
mount at some time over the life of the product. This could be
extremely dangerous, for example, in cases where the panes are
carried against the exterior of a tall building or the like.
SUMMARY OF THE INVENTION
[0018] In one embodiment, the invention provides a transparent pane
having generally-opposed first and second major surfaces. Each of
these major surfaces bears a functional coating and has a
peripheral region that is substantially free of the functional
coating.
[0019] In another embodiment, the invention provides a transparent
pane having generally-opposed first and second major surfaces. At
least one of these major surfaces bears an active coating and has a
peripheral region that is substantially free of the active
coating.
[0020] In still another embodiment, the invention provides a
multiple-pane insulating glass unit comprising two spaced-apart
panes and a spacer joining confronting, inner peripheral surfaces
of the panes. The spacer and the confronting surfaces of the panes
together define a between-pane space. At least one of the panes has
an outer surface bearing a functional coating. This outer surface
has a peripheral region that is substantially free of the
functional coating.
[0021] In yet another embodiment, the invention provides a method
of treating a coated substrate. The method comprises providing a
transparent pane having generally-opposed first and second major
surfaces. Each of these major surfaces bears a functional coating.
Substantially all of the functional coating is removed from a
peripheral region of the first major surface. Likewise,
substantially all of the functional coating is removed from a
peripheral region of the second major surface.
[0022] In a further embodiment, the invention provides a glazing
assembly comprising a transparent pane having generally-opposed
first and second major surfaces. At least one of these major
surfaces bears an active coating. The glazing assembly includes
frame in which at least one edge of the pane is received. The frame
has a mounting surface against which the coated pane surface is
retained. A bead of glazing compound is disposed between the
mounting surface of the frame and a peripheral region of the coated
pane surface. The glazing compound is shielded from direct contact
with the active coating by a barrier layer provided between the
coated pane surface and the glazing compound.
[0023] In another embodiment, the invention provides a glazing
assembly comprising a transparent pane having generally-opposed
first and second major surfaces. At least one of these major
surfaces bears an active coating. The glazing assembly includes a
frame in which at least one edge of the pane is received. The frame
has a mounting surface against which the coated pane surface is
retained. A bead of glazing compound is disposed between the
mounting surface of the frame and a peripheral region of the coated
pane surface. The glazing compound is in direct contact with the
active coating and comprises a material that is durable to the
active coating.
[0024] In still another embodiment, the invention provides a
frameless glazing assembly. The frameless glazing assembly
comprises a transparent pane having generally-opposed first and
second major surfaces. At least one of these major surfaces bears
an active coating and has one or more surface regions that are each
substantially free of the active coating. The assembly includes one
or more mounts bounding a glazing opening in which the transparent
pane is mounted. Each mount defines a mounting surface against
which the coated pane surface is retained. A bead of glazing
compound is disposed between each mount surface and a respective
one of the coating-free surface regions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a schematic cross-sectional view of a known
multiple-pane insulating glass unit;
[0026] FIG. 2 is a cross-sectional view of another known
multiple-pane insulating glass unit;
[0027] FIG. 3 is a cross-sectional view of a frame in which the
multiple-pane insulating glass unit of FIG. 2 has been mounted;
[0028] FIG. 4 is a cross-sectional view of a coated substrate in
accordance with one embodiment of the present invention;
[0029] FIG. 5 is a cross-sectional view of a frame in which the
coated substrate of FIG. 4 has been mounted in accordance with
another embodiment of the invention;
[0030] FIG. 6A is a front view of a major surface of a coated
substrate in accordance with still another embodiment of the
invention;
[0031] FIG. 6B is a front view of a major surface of a coated
substrate in accordance with yet another embodiment of the
invention;
[0032] FIG. 7 is a cross-sectional view of a multiple-pane
insulating glass unit in accordance with a further embodiment of
the invention;
[0033] FIG. 8 is a cross-sectional view of a frame in which the
multiple-pane insulating glass unit of FIG. 7 has been mounted in
accordance with another embodiment of the invention;
[0034] FIG. 9 is a cross-sectional view of a frame in which a
coated substrate has been mounted in accordance with a further
embodiment of the invention;
[0035] FIG. 10 is a cross-sectional view of a frame in which a
multiple-pane insulating glass unit has been mounted in accordance
with another embodiment of the invention;
[0036] FIG. 11 is a cross-sectional view of a frame in which a
coated substrate has been mounted in accordance with still another
embodiment of the invention;
[0037] FIG. 12 is a cross-sectional view of a frame in which a
multiple-pane insulating glass unit has been mounted in accordance
with yet another embodiment of the invention;
[0038] FIG. 13 is a cross-sectional view of a coated substrate in
accordance with a further embodiment of the invention; and
[0039] FIG. 14 is a cross-sectional view of a frameless glazing
assembly in accordance with another embodiment of the
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] The present invention provides edge treatments for coated
substrates. These edge treatments afford particular advantage in
mounting coated substrates into window frames and the like. In the
present disclosure, the term "interior coating" is used to refer to
a coating that is exposed to the between-pane space 115 of an IG
unit. On the other hand, the term "exterior coating" is used herein
to refer to a coating that is exposed to an environment other than
the between-pane space 115 of an IG unit. Typically, exterior
coatings will be exposed to unprotected, ambient environments.
However, by identifying a given coating as an exterior coating, it
is not necessarily represented that the coating is exposed to an
outdoor environment, for example, unless such requirement is
specifically stated.
[0041] The invention can be used favorably with a wide variety of
substrates. In particular, the substrate class comprising generally
flat, sheet-like substrates is favored. A substrate of this nature
typically has two generally-opposed major surfaces. In most cases,
the substrate will be a sheet of transparent material (i.e., a
transparent pane). For example, the substrate may be a pane of
glass. One type of glass that is commonly used in manufacturing
glass articles (e.g., insulating glass units) is soda-lime glass.
Soda-lime glass will be a preferred substrate in many cases. Of
course, other types of glass can be used as well, including those
generally referred to as alkali-lime-silicon dioxide glass,
phosphate glass, and fused silicon dioxide. It is noted that the
substrate is not required to be transparent. For example, opaque
substrates may be useful in some cases. However, it is anticipated
that for most applications, the substrate will comprise a
transparent or translucent material, such as glass or clear
plastic.
[0042] The invention provides numerous embodiments wherein a coated
substrate is provided with at least one exterior coating. Unless
expressly stated, the exterior coating in each embodiment can be of
any desired type. For example, it is contemplated that the
invention will bestow particular benefit upon substrates bearing an
active exterior coating, such as an exterior photocatalytic
coating. It is to be understood that the term "active coating" is
used herein to refer to a coating, whether currently known or
subsequently developed, that has self-cleaning properties. As noted
above, self-cleaning coatings may be degenerative to glazing
compound and the like. Therefore, the edge treatments of this
invention are particularly advantageous for substrates bearing
active (or "self-cleaning") coatings.
[0043] A variety of photocatalytic coatings are known. For example,
useful photocatalytic coatings are described in U.S. Pat. Nos.
5,874,701 (Watanabe et al), 5,853,866 (Watanabe et al), 5,961,843
(Hayakawa et al.), 6,139,803 (Watanabe et al), 6,191,062 (Hayakawa
et al.), 5,939,194 (Hashimoto et al.), 6,013,372 (Hayakawa et al.),
6,090,489 (Hayakawa et al.), 6,210,779 (Watanabe et al), 6,165,256
(Hayakawa et al.), and 5,616,532 (Heller et al.), the entire
teachings of each of which are incorporated herein by
reference.
[0044] The most powerful photocatalytic coatings appear to be based
on titanium oxide (e.g., titanium dioxide or substoichiometric
titanium oxide, TiO.sub.x, such as where x is between 1 and 2).
Useful titanium oxide coatings are disclosed in the book TiO.sub.2
Photocatalysis Fundamentals and Applications (First Edition, May
1999, BKC, Inc.), the entire teachings of which are incorporated
herein by reference. Particularly useful photocatalytic coatings
can be sputter deposited in accordance with the teachings of U.S.
patent application Serial No. 60/262,878, the entire teachings of
which are incorporated herein by reference. In one particularly
useful embodiment, a transparent pane has an edge-deleted
photocatalytic coating on one of its major surfaces and an
edge-deleted low-emissivity coating on its other major surface.
[0045] As noted above, there is a great deal of ongoing research in
the area of self-cleaning coatings. As a consequence, new
photocatalysis-based coatings are being developed on an ongoing
basis. Moreover, the development of self-cleaning coatings based on
mechanisms other than photocatalysis is anticipated. In this
regard, the present invention would be of great value to any
self-cleaning coating that is degenerative to glazing compound or
the like, regardless of the particular mechanism that provides the
self-cleaning effect. Thus, it is anticipated that the present
invention will be used advantageously in connection with
self-cleaning coatings that have yet to be developed, whether or
not these coatings are photocatalytic.
[0046] The present edge treatments can also be used quite
advantageously in connection with substrates bearing an exterior
hydrophilic coating. Hydrophilic coatings have an affinity for
water. As a result, water on a hydrophilic coating will tend to
spread into a uniform sheet, rather than beading up. Hydrophilic
coatings are particularly advantageously for applications where
there will not be a constant flow of high velocity air moving over
the coated surface (e.g., architectural glass applications).
Particularly useful hydrophilic coatings are disclosed in U.S.
patent application Ser. Nos. 09/868,542, 09/868,543, 09/572,766,
and 09/979,325, the entire teachings of each of which are
incorporated herein by reference. In one embodiment, a transparent
pane has an edge-deleted hydrophilic coating on one of its major
surfaces and an edge-deleted low-emissivity coating on its other
major surface.
[0047] The present edge treatments can also be used advantageously
in connection with an exterior hydrophobic coating. Hydrophobic
coatings are characterized by their tendency to repel water. Thus,
water on a hydrophobic coating tends to bead up, forming discrete
droplets, rather than spreading over the coated surface.
Hydrophobic coatings are advantageous for applications where there
will be a constant flow of high velocity air moving over the coated
surface (e.g., automobile windshields). In such applications, the
water-beading effect facilitates water removal from the coated
surface by allowing droplets to be blown readily from the coated
surface. A variety of hydrophobic coatings are known. For example,
useful hydrophobic coatings are disclosed in U.S. Pat. No.
5,424,130 (Nakanishi et al.), the entire teachings of which are
incorporated herein by reference.
[0048] As noted above, the exterior coating or coatings can be of
any desired type in most embodiments of the invention. For example,
it may be desirable to employ an exterior coating that is
antireflective, highly (e.g., selectively) reflective, etc.
Further, skilled artisans will wish to select other types of
coatings to achieve other desired substrate properties. Thus, while
certain types of coatings are discussed herein for illustrative
purposes, the invention is not limited to use with any particular
coatings.
[0049] In many cases, the exterior coating will be exposed to an
unprotected, ambient environment. As a consequence, the exterior
coating is preferably formed of material that does not readily
corrode when exposed to air and moisture. For example, it may be
advantageous if the exterior coating is a non-silver-based coating
(i.e., one that does not contain a major silver component). In
fact, it may be preferable to employ exterior coatings that are
substantially, or even entirely, free of silver and other materials
that are vulnerable (e.g., that corrode when exposed) to oxygen,
moisture, or other components of ambient air. However, certain
silver-containing coatings may actually be advantageous for use as
an exterior coating (e.g., those having appropriate protection of
the silver). As such, it may be preferable to incorporate a
silver-based exterior coating into certain embodiments hereof.
[0050] It is presently contemplated that the exterior coating will
be a thin film coating (e.g., comprising one or more layers of
metal, metal alloy, and/or dielectric material). While there are no
thickness limitations on coatings of the invention, it is
contemplated that each coating will have an overall thickness of
well below 10,000 angstroms (e.g., less than about 2000 or about
3000 angstroms). For example, in embodiments involving a
photocatalytic coating, the total thickness of the coating may be
on the order of 1,000 angstroms or less, and more preferably on the
order of 500 angstroms or less.
[0051] FIG. 4 illustrates one embodiment of the invention that
involves a coated substrate 10. The substrate 10 has generally
opposed first 12 and second 12' major surfaces. In this particular
embodiment, each major surface bears a functional coating. The
functional coating on the first major surface 12 is designated by
the reference numeral 20, while the functional coating on the
second major surface 12' is designated by the reference numeral
20'. The nature of these coatings can be varied depending on the
properties intended for the coated substrate 10. For example, one
or both coatings in this embodiment can be an exterior coating.
Thus, any of the coating types discussed above would be suitable.
In one embodiment, one of the coatings is a photocatalytic coating
and the other is a low-emissivity coating. In another embodiment,
one of the coatings is a hydrophilic coating and the other is a
low-emissivity coating. A variety of other coatings and coating
combinations could also be used and would fall within the scope of
the invention.
[0052] Edge deletion has been performed on both major surfaces of
the illustrated substrate 10. That is, each major surface has a
peripheral region from which the functional coating has been
substantially removed. For example, the first major surface 12 has
a peripheral region 120 from which the functional coating 20 has
been substantially removed. Likewise, the second major surface 12'
has a peripheral region 120' from which the functional coating 20'
has been substantially removed. As discussed below, each
coating-free peripheral region can extend completely about the
periphery of the coated surface, or it may extend only about a
partial periphery of the coated surface, as desired. The
coating-free peripheral regions 120, 120' facilitate substrate
installation, as will be appreciated given the present
teaching.
[0053] A substrate like that shown in FIG. 4 can be used in a
variety of applications. For example, a substrate 10 of this nature
can be used as one of the panes in a multiple-pane IG unit (as
illustrated in, and discussed with reference to, FIG. 7).
Alternatively, a substrate of this nature can be used in a
monolithic glazing assembly (as illustrated in, and described with
reference to, FIG. 5). Skilled artisans will also appreciate other
applications (e.g., frameless glazing applications) that would
derive benefit from a coated substrate of this nature.
[0054] FIG. 5 illustrates an embodiment wherein a monolithic
substrate 10 has been installed in a frame 50. The term "frame" is
used herein to refer to any structure to which a monolithic
substrate or IG unit can be mounted. The term would include frames,
sashes, and any other structure that serves a similar purpose. In
most cases, the frame will be configured to receive at least one
edge (and typically all edges) of a monolithic pane or IG unit.
While the illustrated frame has a very simple construction, any
desired frame design can be used. Moreover, the frame 50 can be
part of a window, door, skylight, or any other type of glazing
assembly.
[0055] In FIG. 5, both of the coatings 20, 20' are depicted as
being exterior coatings (i.e., neither is exposed to the
between-pane space of an IG unit). The invention provides a number
of different embodiments of this nature. For example, in one
preferred embodiment, both coatings 20, 20' are photocatalytic. In
another preferred embodiment, both coatings 20, 20' are
hydrophilic. In still another preferred embodiment, the first
coating 20 is photocatalytic and the second coating 20' is
hydrophilic. Many other types of coatings and coating combinations
can be used and would fall within the scope of the invention.
[0056] The edge 10E of the substrate 10 in FIG. 5 is retained in a
glazing channel 60 of the frame 50. Thus, the width of the glazing
channel 60 in this embodiment is preferably substantially equal to,
or slightly greater than, the width of the pane 10. The
coating-free peripheral regions 120, 120' of the substrate 10 are
encased by confronting mounting surfaces 55 of the frame 50. In the
illustrated embodiment, glazing compound 70 has been applied
between both coating-free peripheral regions 120, 120' and
respective confronting mounting surfaces 55 of the frame 50. For
example, the glazing compound 70 adjacent the first major surface
12 is bonded directly to the first coating-free peripheral region
120. Likewise, the glazing compound 70 adjacent the second major
surface 12' is bonded directly to the second coating-free
peripheral region 120'. By bonding the glazing compound directly to
these uncoated surfaces, reliable bonds can be formed between the
glazing compound and the pane 10.
[0057] The frame construction and manner of applying glazing
compound can be varied. For example, a single bead of glazing
compound may be applied between only one of the confronting frame
surfaces 55 and the adjacent coating-free peripheral region. In
such cases, it will be particularly advantageous to edge delete the
peripheral region of the surface that will be bonded to the glazing
compound (or to utilize one of the other edge treatments of the
invention on this surface), as the adhesion of this bead of glazing
material may be all that keeps the substrate 10 from being loose in
the glazing channel 60. This may be even more important for
frameless glazing assemblies, like that illustrated in FIG. 14, as
the glazing compound's adherence to the pane 10 would obviously be
important for pane retention.
[0058] In FIG. 5, the edge 10E of the pane 10 is depicted as being
spaced-apart from the base mounting surface 53. The monolithic
panes and IG units of FIGS. 7-12 are also illustrated in this
manner. However, this is done for illustration purposes, and there
typically would not be significant space between an installed
monolithic pane or IG unit and the base mounting surfaces of a
frame. For example, monolithic panes and IG units are commonly
installed such that the edges 10E of each pane abut the base
mounting surfaces 53. In some cases, though, a gasket and/or
glazing compound can be provided between the edges 10E of each pane
and the base mounting surfaces 53.
[0059] The coating-free peripheral region extends a certain
distance inwardly from the edge 10E of the substrate 10. This
distance, which may be predetermined, is referred to herein as the
"edge-deletion width". Specifically, the edge-deletion width is
defined as the distance from an edge 10E of a substrate, along a
coated major surface of the substrate, to an adjacent edge 20E of
the remaining coating 20. Generally speaking, an edge-deletion
width of less than about one inch, and perhaps optimally about 1/2
inch, would be suitable for most conventional applications. Of
course, different edge-deletion widths can be selected for
different applications. In most cases, it will be preferable to
employ an edge-deletion width that is uniform along all sides of
the coated surface, at least along the length of a given side of
the coated surface.
[0060] The edge-deletion width is preferably selected such that the
coating-free region will be hidden from view once the substrate has
been mounted. This is expected to be advantageous in all
embodiments of the invention, particularly in cases where the
deleted coating is optically significant, as the boundaries of the
coating-free regions may otherwise be visible. Thus, it is
preferable for each coating-free peripheral region to be outside
the vision area of the glazing assembly. For example, each
coating-free peripheral region can be hidden from view by the
shoulders 57 of a frame 50. In more detail, the outer edge 20E,
20'E, 40E, 420E of the edge deleted coating 20, 20', 40, 420 is
preferably positioned further outward (i.e., closer to the mounting
surface 53 of the frame 50) than the inner edge 57E of the
shoulders 57 of the frame 50 after installation. In cases where the
edge of each pane is mounted directly against the base mounting
surface 53 of a frame 50, this can be accomplished by selecting an
edge-deletion width that is less than the depth of the glazing
channel 60. In cases where a gasket and/or glazing material is
positioned between the edge of each pane and the base mounting
surface 53 of the frame 50, this can be accomplished by selecting
an edge-deletion width that is less than the distance the
confronting frame surfaces 55 will extend over respective
peripheral pane surfaces. In other words, it is generally preferred
to select edge-deletion widths that will leave the coating-free
peripheral regions hidden from view following installation.
[0061] FIG. 5 illustrates an embodiment wherein the glazing
compound 70 is bonded only to the coating-free peripheral regions
120, 120' of the substrate 10 (i.e., with no overlap of glazing
compound and coating). While this is preferred to assure reliable
bonding, it is not a strict requirement. For example, some of the
glazing compound may somewhat overlap the remaining exterior
coating. However, it is preferable in these cases if a major
portion of the glazing compound is bonded directly to the
coating-free peripheral region. In most cases, it will be desirable
to edge delete enough exterior coating to assure that a
conventional bead of glazing compound can be bonded to each
coating-free peripheral region without any contact between the
glazing compound and the remaining coating.
[0062] It is particularly advantageous to bond the glazing compound
only to the coating-free peripheral region when the edge-deleted
coating is an active coating. Active coating is preferably not
placed in direct contact with conventional glazing compound, as the
coating may otherwise chemically degrade the glazing compound.
While this chemical degradation may not completely destroy the bond
between the glazing compound and the pane, it may still adversely
affect the seal between the glazing compound and the pane.
[0063] In addition to varying the edge-deletion width, the
configuration of each coating-free peripheral region can be varied
as desired. For example, FIG. 6A illustrates an embodiment wherein
edge deletion has been performed about the entire periphery of the
coated surface. In most cases, it will be preferable to edge delete
in this manner. For example, when a substrate is mounted in a
conventional window frame, the glazing compound is typically
applied about the entire periphery of the substrate. In other
cases, multiple substrates may be installed in an edge-to-edge
fashion, such that the glazing compound is only applied about two
peripheral areas of the pane (e.g., top and the bottom peripheral
areas). In such cases, it would not be necessary to edge delete the
entire periphery of the coated surface. For example, FIG. 6B
illustrates an embodiment wherein edge deletion has only been
performed on the top and bottom peripheral areas of the coated
surface.
[0064] As noted above, a substrate 10 like that shown in FIG. 4 can
be incorporated into a multiple-pane IG unit. One embodiment of
this nature is illustrated in FIG. 7. In this embodiment, at least
one of the panes 10, 10' bears a functional coating on its outer
surface (i.e., the surface oriented away from the between-pane
space 115). In other words, the IG unit of this embodiment carries
at least one exterior coating. In FIG. 7, the outer surface 12 of
the first pane 10 bears a functional coating 20, while the outer
surface 12' of the second pane 10' is uncoated. Alternatively, the
outer surface 12' of the second pane 10' can be provided with a
functional coating (not shown), and the outer surface 12 of the
first pane 10 can be left uncoated. As still another alternative,
the outer surfaces of both panes can be provided with functional
coatings, if so desired.
[0065] The nature of the exterior coating or coatings can be varied
depending on the properties intended for the IG unit. For example,
any of the exterior coating types discussed above would be suitable
for use in this embodiment. In one particularly preferred
embodiment, the exterior coating 20 illustrated in FIG. 7 is an
active coating (e.g., a photocatalytic coating). In another
particularly preferred embodiment, this coating 20 is a hydrophilic
coating. In other embodiments, this coating may be hydrophobic,
highly (e.g., selectively) reflective, or antireflective. In most
case, it is desirable to form each exterior coating of material
that does not readily corrode when exposed to air and moisture.
[0066] As noted above, if both panes of the IG unit bear exterior
coatings, then the nature of these two coatings can be the same or
different, depending on the properties intended for the IG unit.
For example, an IG unit like that depicted in FIG. 7 can be
provided with active exterior coatings on both panes 10, 10' (not
shown). Alternatively, an IG unit of this nature can be provided
with hydrophilic exterior coatings on both panes. As still another
alternative, an active coating can be provided on one pane, while
another functional coating (e.g., a hydrophilic or hydrophobic
coating) is provided on the outer surface of the other pane. Many
other combinations are possible and would fall within the scope of
the invention.
[0067] In the present embodiment, the IG unit has at least one
exterior coating that is edge deleted. In FIG. 7, only the first
pane 10 of the IG unit bears an exterior functional coating 20.
Thus, the outer surface 12 of this pane 10 has been edge deleted.
That is, it has a peripheral region 120 that is substantially free
of the functional coating 20. As discussed below, this facilitates
reliable installation of the IG unit. In cases where both panes of
the IG unit are provided with exterior coatings, it will typically
be advantageous to edge delete the coatings from the outer surfaces
of both panes.
[0068] In embodiments of the invention that involve a multiple-pane
IG unit, one or both panes can optionally be provided with an
interior low-emissivity coating. Low-emissivity coatings are quite
well known in the present art. Particularly useful low-emissivity
coatings are described in U.S. patent application Ser. Nos.
09/728,435, 09/898,545, and 09/189,284. Moreover, a
pyrolytically-applied low-emissivity coating can be incorporated
into any embodiment of the invention, in the nature of an interior
and/or exterior coating. Coatings of this nature are described in
U.S. Pat. No. 5,698,262 (Soubeyrand et al.), the entire teachings
of which are incorporated herein by reference.
[0069] In FIG. 7, the first pane 10 of the IG unit bears an
interior low-emissivity coating 40. Alternatively, the second pane
10' can be provided with an interior low-emissivity coating (not
shown). As another alternative, both panes can be provided with
interior low-emissivity coatings, if so desired. Each interior
low-emissivity coating 40 is preferably edge deleted to facilitate
bonding with the spacer 101. This is illustrated in FIG. 7, wherein
the inner surface of the first pane 12 has a peripheral region 140
that is substantially free of the low-emissivity coating 40.
[0070] FIG. 8 illustrates an embodiment wherein a multiple-pane IG
unit has been mounted in frame. The resulting glazing assembly
generally includes the IG unit, the frame, and glazing compound 70.
The IG unit of FIG. 8 has the same basic structure as that shown in
FIG. 7. Similarly, the frame 50 illustrated in FIG. 8 has the same
basic structure as that of FIG. 5. For example, the frame 50 is
configured to receive at least one edge of the IG unit. Thus, the
edge regions of the IG unit are encased by confronting mounting
surfaces 55 of the frame 50. Unlike the frame in FIG. 5, however,
the frame in FIG. 8 is adapted to accommodate a multiple-pane IG
unit, rather than a monolithic pane. Thus, the width of the glazing
channel 60 in this embodiment is preferably substantially equal to,
or slightly greater than, the width of the IG unit.
[0071] In the present embodiment, at least one of the panes carries
a functional coating on its outer surface. In FIG. 8, the first
pane 10 bears a functional exterior coating 20. Alternatively, the
second pane 10' can be provided with a functional exterior coating
(not shown). As still another alternative, the outer surfaces of
both panes can be provided with functional coatings. As with the IG
unit of FIG. 7, the nature of each exterior coating in the
embodiment of FIG. 8 can be varied depending on the properties
intended for the mounted IG unit.
[0072] In this embodiment, the mounted IG unit bears at least one
edge-deleted exterior coating. In FIG. 8, the first pane 10 of the
IG unit bears the edge-deleted exterior coating 20. Thus, the outer
surface 12 of this pane 10 has a peripheral region 120 that is
substantially free of the functional coating 20. A bead of glazing
compound 70 is disposed between this coating-free peripheral region
120 and the adjacent mounting surface 55 of the frame 50. This
coating-free peripheral region 120 provides an uncoated surface to
which the glazing compound 70 is directly bonded. This allows a
strong, durable bond to be formed between the glazing compound and
the pane. In cases where both panes of a mounted IG unit bear
exterior coatings (not shown), it will be preferable to edge delete
the outer surfaces 12, 12' of both panes 10, 10', at least if
glazing compound 70 will be applied against the outer surfaces of
both panes.
[0073] One or both panes of the mounted IG unit can be provided
with an optional interior low-emissivity coating 40. For example,
the first pane 10 of the IG unit bears an interior low-emissivity
coating 40. Alternatively, the second pane 10' can be provided with
an interior low-emissivity coating (not shown). In fact, both panes
can be provided with interior low-emissivity coatings, if so
desired. Each interior low-emissivity coating 40 is preferably edge
deleted to facilitate bonding with the spacer 101. Thus, the inner
surface 14 of the first pane 12 illustrated in FIG. 8 has a
peripheral region 140 that is substantially free of the
low-emissivity coating 40. It may be preferable to edge delete such
interior low-emissivity coatings such that they will be outside the
vision area of the glazing assembly following installation.
[0074] In embodiments that involve a monolithic pane or IG unit
mounted in a frame with glazing compound, the glazing compound
desirably prevents water from infiltrating between the frame and
the pane or IG unit. Thus, it is desirable to maintain the
integrity of the bond between the glazing compound and each pane.
For example, in the embodiment of FIG. 8, if the bond between the
glazing compound 70 and the first pane 10 were to deteriorate,
water could gather in the glazing channel 60. In severe
circumstances, this could leave the bottom of the IG unit sitting
in water, which could eventually cause failure of the IG unit's end
seal. Thus, it is desirable to assure that any exterior coating on
a mounted pane or IG unit will not adversely affect the bonding of
glazing compound to the IG unit. The edge treatments of the present
invention are quite advantageous in this regard.
[0075] FIG. 13 depicts another preferred embodiment of the
invention. In this embodiment, there is provided a substrate (e.g.,
a transparent pane) having generally-opposed first and second major
surfaces. At least one of the major surfaces 12, 12' bears an
active coating 420 (e.g., a photocatalytic coating). This coating
420 is preferably, though not necessarily, an exterior coating. The
active coating 420 is edge deleted, such that the surface 12
bearing this coating 420 has a peripheral region 120 that is
substantially free of the active coating. The width (i.e., the
edge-deletion width) of the coating-free peripheral region 120 is
preferably substantially uniform (and is optionally predetermined)
over the entire periphery of the pane, or at least along the length
of a given side of the coated surface, as described above. In the
present embodiment, the other major surface 12' of the substrate 10
may be uncoated, or it may bear its own coating. For example, both
surfaces 12, 12' of the substrate 10 may bear active coatings.
Further embodiments of this nature are discussed above with
reference to FIGS. 4 and 5.
[0076] FIG. 14 depicts still another preferred embodiment of the
invention. This embodiment involves a frameless glazing assembly.
In FIG. 14, the illustrated glazing assembly includes an IG,
although it will be appreciated that the frameless mounting
structure may alternatively carry a monolithic pane. The
illustrated mounting structure comprises one or more mounts 150,
which are depicted in FIG. 14 as bodies having a generally
"L"-shaped cross section. The mount or mounts 150 bound a glazing
opening in which the IG is mounted. The present embodiment is not
limited to any particular type of frameless mounting structure. To
the contrary, other types of frameless mounting structures (e.g.,
having differently configured mounting surfaces, to which the pane
or IG is affixed) can be used and would fall within the scope of
the invention.
[0077] With continued reference to FIG. 14, the illustrated
frameless mounting structure has mounting surfaces 155 to which the
IG unit is adhesively affixed. A bead of glazing compound, sealant,
or adhesive is applied between each mounting surface 155 and a
peripheral region of the first pane 10. The outer surface 12 of
this pane 10 bears an active coating 42 (e.g., a photocatalytic
coating). The active coating 420 in this embodiment is edge
deleted. That is, the outer surface 12 of the first pane 10 has a
peripheral region 120 that is substantially free of the active
coating 420. This allows the glazing compound 70 to be bonded
directly to the coating-free peripheral region 120 of the pane 10.
As noted above, this facilitates reliable bonding of the glazing
compound 70 to the pane 10. In frameless glazing 10 embodiments, it
can be appreciated that the integrity of the bond between the
glazing compound 70 and the pane 10 is particularly important. For
example, failure of this bond could conceivably cause the mounted
pane or IG unit to fall from its mount, potentially creating a
safety hazard, especially in cases where the pane or IG unit is
mounted to the exterior of a tall building or the like.
[0078] The present invention also provides methods for treating a
coated substrate. These method involve providing a substrate (e.g.,
a transparent pane) having generally opposed first and second major
surfaces each bearing a functional coating. The functional coating
is substantially removed from a peripheral region of the first
major surface. Likewise, the functional coating is substantially
removed from a peripheral region of the second major surface. This
edge deletion can be performed using any desired coating-removal
technique.
[0079] In a favored method of the invention, these coatings are
removed by performing grinding operations on the substrate. For
example, a conventional grinding wheel can be moved manually about
the periphery of each coated surface. Alternatively, a grinding
wheel can be mounted in a fixed position while the substrate is
translated past, and acted upon by, the grinding wheel. Useful
grinding wheels and grinding methods are described in U.S. Pat.
Nos. 4,716,686 (Lisec) and 5,934,982 (Vianello et al.), the entire
teachings of each of which are incorporated herein by reference.
Rather than grinding away these coatings, edge deletion can be
performed using torches fueled by combustible gas, through
electrical discharge, or using any other desired coating-removal
process.
[0080] In a particularly favored method of the invention, the
functional coatings are removed from both coated surfaces
substantially simultaneously. For example, edge deletion can be
performed on both major surfaces of a substrate in a single pass
through a grinding apparatus. In one method, two grinding wheels
are used to simultaneously edge delete the coatings from both major
surfaces of the substrate. The method involves first and second
grinding wheels positioned on opposite sides (e.g., above and
below) of a path along which the substrate will travel (i.e., on
opposite sides of the path of substrate travel). The grinding
wheels are preferably separated by a distance that is substantially
equal to the thickness of the uncoated substrate. The substrate is
translated between the grinding wheels such that coatings are
removed simultaneously from both major surfaces of the substrate.
Particularly useful edge-deletion equipment and methods are
described in U.S. patent application Serial No. 60/267,507, the
entire teachings of which are incorporated herein.
[0081] FIG. 9 illustrates a further embodiment of the invention
involving a monolithic glazing assembly. In this embodiment, the
invention provides a glazing assembly that generally includes a
monolithic substrate (e.g., a transparent pane), a frame, and
glazing compound. The substrate 10 has generally opposed first 12
and second 14 major surfaces. At least one of the major surfaces
bears an active coating (e.g., a photocatalytic coating). In FIG.
9, the substrate 10 bears an active coating 420 on its first major
surface 12, while its second major surface 12' is uncoated.
Alternatively, the second major surface 12' can be provided with an
active coating (not shown), and the first major surface 12 can be
left uncoated. As still another alternative, both major surfaces of
the substrate can be provided with coatings. For example, active
coatings can be provided on both major surfaces. Alternatively, an
active coating can be provided on one major surface, while another
type of coating (e.g., hydrophilic, hydrophobic, etc.) is provided
on the other major surface. In such cases, the nature of the
coating on the other major surface (i.e., the non-active coating)
can be varied depending on the properties intended for the coated
substrate.
[0082] In the present embodiment, the surface 12 bearing the active
coating 420 is retained against a mounting surface 55 of the frame
50. Thus, in FIG. 9, the first major surface 12 of the substrate 10
is retained against the adjacent mounting surface 55 of the frame
50. The illustrated frame 50 has the construction described above
(e.g., having a generally "C"-shaped cross section), wherein at
least one edge (e.g., all edges) of the substrate is received in
the frame. However, any desired frame construction can be used in
this embodiment.
[0083] In FIG. 9, glazing compound is applied between the frame and
both major surfaces of the pane, although this is not a
requirement. For example, the glazing compound 70 can simply be
disposed between a peripheral region of the surface 12 bearing the
active coating 420 and the adjacent mounting surface 55 of the
frame 50. In the present embodiment, a barrier layer 90 is provided
between the active coating 420 and the glazing compound 70. This
barrier layer 90 shields the glazing compound from direct contact
with the active coating 420. The barrier layer 90 is provided to
prevent deterioration of the glazing compound by keeping the
glazing compound and the active coating out of contact with one
another.
[0084] The barrier layer 90 can be applied between the glazing
compound 70 and the active coating 20 in any desired manner. It may
be preferable to secure the barrier layer 90 to the substrate 10
prior to installation. This would allow the substrate to be
positioned on the frame without having to simultaneously manipulate
the substrate 10 and the barrier layer 90 relative to one another.
For example, the barrier layer 90 may be applied (e.g., painted,
sprayed, etc.) onto the substrate in the form of a liquid that can
subsequently be solidified (e.g., by applying heat). In one
preferred embodiment, the barrier layer 90 is printed, stamped,
taped, or extruded onto the peripheral region of the coated surface
12. For example, the barrier layer 90 may be applied in the form of
a printable foil or film. Yet another alternative (not shown)
involves forming a sealing strip comprising a barrier layer portion
(such as may be provided in the form of a backing for the sealing
strip) on one side and a glazing compound portion on the other
side. A sealing strip of this nature could be adhered to the
mounting surface 55 of the frame 50 with its barrier layer portion
oriented toward the intended position of the substrate 10.
[0085] The barrier layer 90 is advantageously formed of material
that is durable to the active coating 20. That is, the barrier
layer 90 is preferably formed of material that is resistant to the
self-cleaning mechanism of the active coating, whatever that
mechanism may be. This is preferable so the barrier layer 90 itself
will not be chemically degraded by the active coating 20. For
example, in cases where the active coating 20 is photocatalytic,
the barrier layer 90 is desirably formed of material (e.g., an
inorganic material) that is resistant to attack by the free
radicals that can be generated at the surface of a
photocatalyst.
[0086] The barrier layer 90 is preferably positioned entirely
outside the vision area of the glazing assembly. Thus, the barrier
layer 90 is desirably sized, shaped, and positioned such that its
inner edge 90I is below (or outside) the inner edge 571 of the
frame. Since the barrier layer 90 will commonly be out of sight, it
is possible to employ metals and other durable materials that are
thick enough and/or opaque enough to be optically significant.
Thus, in one embodiment, the barrier layer 90 comprises an
optically transparent film of metal, metal alloy, or dielectric
material.
[0087] The barrier layer can be formed of a variety of durable
materials. For example, U.S. Pat. No. 5,547,825 ("the '825
patent"), the entire teachings of which are incorporated herein by
reference, describes a number of materials as being durable to
photocatalysis. It is anticipated that these materials would be
useful in forming the present barrier layer 90. These materials
include silicon compounds, such as water glass, colloidal silica,
polyorganosiloxanes, and the like. Also included are phosphates,
such as zinc phosphate and aluminum phosphate. The '825 patent also
describes certain organic materials, including fluorinated polymers
and silicone-based polymers, as being durable to photocatalysis.
U.S. Pat. Nos. 5,616,532, 5,849,200, and 5,854,169, the entire
teachings of each of which are incorporated herein by reference,
also disclose materials that are expected to be useful in forming
the present barrier layer 90.
[0088] Fluorinated polymers may be advantageous when it is
important to maximize the adhesive strength of the barrier layer
90. It is anticipated that a variety of fluorinated polymers would
be advantageous in this regard, including: crystalline fluorinated
resins such as polyvinyl fluorides, polyvinylidene fluorides,
polyethylene trifluorochlorides, polyethylene tetrafluorides,
tetrafluoroethylene-hexafluoropropylene copolymers,
ethylene-polyethylene tetrafluoride copolymers, ethylene-ethylene
trifluorochloride copolymers, tetrafluoroethylene-perfl-
uoroalkylvinyl ether copolymers, amorphous fluorinated resins such
as perfluorocyclo polymers, vinylether-fluoroolefin copolymers,
vinylester-fluoroolefin copolymers, various fluorinated elastomers
and the like. Fluorinated polymers comprising primarily
vinylether-fluoroolefin copolymers and vinylester-fluoroolefin
copolymers may be particularly advantageous, as they tend to be
easy to handle and perhaps even less susceptible to decomposition
and degradation.
[0089] Silicone-based polymers are also believed to be advantageous
when the adhesive strength of the barrier layer 90 is preferably
maximized. It is anticipated that a variety of silicone-based
polymers would be advantageous in this regard, including: linear
silicone resins, acryl-modified silicone resins, various silicone
elastomers, and the like. Examples include methyltrichlorosilane,
methyltribromosilane, methyltrimethoxysilane,
methyltriethoxysilane, methyltriisopropoxysilane,
methyltri-t-buthoxysilane; ethyltrichlorosilane,
ethyltribromosilane, ethyltrimethoxysilane, ethyltriethoxysilane,
ethyltriisopropoxysilane, ethyltri-t-buthoxysilane;
n-propyltrichlorosilane, n-propyltribromosilane,
n-propyltrimethoxysilane, n-propyltriethoxysilane- ,
n-propyltriisopropoxysilane, n-propyltri-t-buthoxysilane;
n-hexyltrichlorosilane, n-hexyltribromosilane,
n-hexyltrimethoxysilane, n-hexyltriethoxysilane,
n-hexyltriisopropoxysilane, n-hexyltri-t-buthoxysilane;
n-decyltrichlorosilane, n-decyltribromosilane,
n-decyltrimethoxysilane, n-decyltriethoxysilane,
n-decyltriisopropoxysilane, n-decyltri-t-buthoxysilane;
n-octadecyltrichlorosilane, n-octadecyltribromosilane,
n-octadecyltrimethoxysilane, n-octadecyltriethoxysilane,
n-octadecyltriisopropoxysilane, n-octadecyltri-t-buthoxysilane;
phenyltrichlorosilane, phenyltribromosilane,
phenyltrimethoxysilane, phenyltriethoxysilane,
phenyltriisopropoxysilane, phenyltri-t-buthoxysila- ne;
tetrachlorosilane, tetrabromosilane, tetramethoxysilane,
tetraethoxysilane, tetrabuthoxysilane, dimethoxydiethoxysilane;
dimethyldichlorosilane, dimethyldibromosilane,
dimethyldimethoxysilane, dimethyldiethoxysilane;
diphenyldichlorosilane, diphenyldibromosilane,
diphenyldimethoxysilane, diphenyldiethoxysilane;
phenylmethyldichlorosila- ne, phenylmethyldibromosilane,
phenylmethyldimethoxysilane, phenylmethyldiethoxysilane;
trichlorohydrosilane, tribromohydrosilane, trimethoxyhydrosilane,
triethoxyhydrosilane, triisopropoxyhydrosilane,
tri-t-buthoxyhydrosilane; vinyltrichlorosilane,
vinyltribromosilane, vinyltrimethoxysilane, vinyltriethoxysilane,
vinyltriisopropoxysilane, vinyltri-t-buthoxysilane;
trifluoropropyltrichlorosilane, trifluoropropyltribromosilane,
trifluoropropyltrimethoxysilane, trifluoropropyltriethox.silane,
trifluoropropyltriisopropoxysilane,
trifluoropropyltri-t-buthoxysilane;
gamma-glycidoxypropylmethyldimethoxys- ilane,
gamma-glycidoxypropylmethyldiethoxysilane,
gamma-glycidoxy-propyltr- imethoxysilane,
gamma-glycidoxypropyltriethoxysilane,
gamma-glycidoxypropyltriisopropoxysilane, gamma-glycidoxy
propyltri-t-buthoxysilane; gamma-methacryloxypropylmethyl
dimethoxysilane, gamma-methacryloxy-propylmethyldiethoxysilane,
gamma-methacryloxypropyltrimethoxysilane,
gamma-methacryloxy-propyltrieth- oxysilane,
gamma-methacryloxypropyltriisopropoxy silane,
gamma-methacryloxypropyltri-t-buthoxysilane;
gamma-aminopropylmethyldimet- hoxysilane; gamma-aminopropylmethyl
diethoxysilane,
gamma-aminopropyltrimethoxysilane,gamma-aminopropyltriethoxysilane,
gamma-aminopropyltriisopropoxy silane,
gamma-aminopropyltri-t-buthoxysila- ne;
gamma-mercaptopropylmethyldimethoxysilane, gamma-mercaptopropyl
methyldiethoxysilane, gamma-mercaptopropyltrimethoxysilane,
gamma-mercaptopropyltriethoxysilane, gamma-mercaptopropyl
triisopropoxysilane, gamma-mercaptopropyltri-t-buthoxysilane;
.beta.-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,
.beta.-(3,4-epoxycyclohexyl) ethyltriethoxysilane; partial
hydrolizates of any of the foregoing; and mixtures of any of the
foregoing.
[0090] In many cases, it will be preferable to form the barrier
layer 90 of material that offers minimal permeability to water.
Materials displaying this property include, but are not limited to,
metals, polymers, ceramics, glasses, composites, and combinations
thereof. Of these, polymers (particularly those listed above) are
anticipated to be particularly advantageous.
[0091] FIG. 10 illustrates an embodiment similar to that of FIG. 9,
but wherein a multiple-pane IG unit has been mounted in a frame.
The illustrated glazing assembly generally includes an IG unit, a
frame, and glazing compound. This IG unit is of the same basic
nature as that shown in FIG. 7, except that the exterior coating
420 has not been edge deleted. As with the embodiment of FIG. 9,
this IG unit is mounted in the frame 50 such that the edge regions
of the IG unit are encased by confronting mounting surfaces 55 of
the frame 50.
[0092] In the present embodiment, at least one of the panes carries
an active coating on its outer surface. In FIG. 10, the first pane
10 of the IG unit bears the active exterior coating 20.
Alternatively, the outer surface 12' of the second pane 10' can be
provided with an active coating (not shown). As still another
alternative, the outer surfaces of both panes can be provided with
coatings. For example, active coatings can be provided on the outer
surfaces of both panes, if so desired. Alternatively, an active
coating can be provided on the outer surface of one pane, while a
coating of another type is provided on the outer surface of the
other pane. In such cases, the nature of the coating on the outer
surface of the other pane (i.e., the non-active coating) can be
varied depending on the properties intended for the mounted IG
unit.
[0093] In this embodiment, a coated outer surface 12 of the IG unit
is retained against a mounting surface 55 of the frame 50. For
example, the outer surface 12 of the first pane 10 is retained
against the adjacent mounting surface 55 of the frame 50. A bead of
glazing compound 70 is disposed between a peripheral region of the
coated outer surface 12 and the adjacent mounting surface 55 of the
frame 50. This glazing compound 70 is shielded from direct contact
with the active coating 420 by a barrier layer 90 provided between
the coated outer surface 12 and the glazing compound 70. As in the
embodiment of FIG. 9, the barrier layer 90 is provided to prevent
deterioration of the glazing compound by keeping the glazing
compound and the active coating out of direct contact with each
other. The barrier layer 90 in this embodiment can be formed of any
of the materials described above with reference to FIG. 9.
Likewise, the application methods described above would be equally
useful in the embodiment of FIG. 10.
[0094] One or both panes of the glazing illustrated in FIG. 10 can
be provided with an optional interior low-emissivity coating. For
example, the first pane 10 of the illustrated IG unit bears an
interior low-emissivity coating 40. However, the second pane 10'
can be alternatively provided with an interior low-emissivity
coating (not shown). As still another alternative, both panes can
be provided with interior low-emissivity coatings. Each interior
low-emissivity coating 40 is preferably edge deleted to facilitate
bonding with the spacer 101. Thus, the inner surface of the first
pane 12 preferably has a peripheral region 140 that is
substantially free of the low-emissivity coating 40.
[0095] The present edge treatments are particularly advantageous in
cases where monolithic substrates or IG units are provided with an
active exterior coating that would otherwise be placed in direct
contact with glazing compound 70 comprising material to which the
active coating 20 is degenerative. For example, it may be desirable
to employ glazing compound comprising organic material in
conjunction with an exterior photocatalytic coating. As noted
above, organic materials may be chemically degraded if bonded
directly to a photocatalytic coating. Thus, it would be desirable
to assure that active coating and organic glazing compound do not
contact each other. The present edge treatments can be employed
quite advantageously toward this end.
[0096] FIG. 11 illustrates another embodiment of the invention
involving a monolithic glazing. The glazing generally includes a
substrate, a frame, and durable glazing compound. The substrate 10
has generally opposed first 12 and second 14 major surfaces. At
least one of the major surfaces bears an active coating. The
illustrated substrate 10 bears an active coating 420 on its first
major surface 12, while the second major surface 12' is uncoated.
Alternatively, the second major surface 12' can be provided with an
active coating (not shown), and the first major surface 12 can be
left uncoated. As still another alternative, both major surfaces of
the substrate 10 can be provided with coatings. For example, active
coatings can be provided on both major surfaces, if so desired.
Alternatively, an active coating can be provided on one major
surface, while another type of coating is provided on the other
major surface. In such cases, the nature of the coating on the
other major surface (i.e., the non-active coating) can be varied
depending on the properties intended for the substrate.
[0097] In the present embodiment, the coated surface 12 of the
substrate 10 is retained against a mounting surface 55 of the frame
50. In FIG. 11, the first major surface 12 of the substrate 10 is
retained against the adjacent mounting surface 55 of the frame. A
bead of durable glazing compound 170 is disposed between a
peripheral region of the coated surface 12 and the adjacent
mounting surface 55 of the frame 50. The durable glazing compound
170 is in direct contact with the active coating 420 on the
substrate 10. However, this glazing compound 170 is resistant to
the self-cleaning mechanism of the active coating 20 (i.e., it is
durable to the active coating).
[0098] FIG. 12 illustrates another embodiment that involves durable
glazing compound. The illustrated glazing generally includes an IG
unit, a frame, and durable glazing compound. The basic structure
and coating options for the IG unit of FIG. 12 are generally the
same as those discussed above with reference to FIG. 10. Thus,
while the IG unit of FIG. 12 is depicted carrying only one exterior
coating 420 and an optional interior low-emissivity coating 40,
additional coatings can be provided depending on the properties
desired for the IG unit.
[0099] In the embodiments of FIGS. 11 and 12, the glazing compound
170 can be formed of a variety of durable materials. For example,
the materials disclosed in the above-referenced '825 patent are
anticipated to be useful components of the durable glazing compound
170. As noted above, these materials include silicon compounds
(e.g., water glass, colloidal silica, polyorganosiloxanes, etc.),
phosphates (e.g., zinc phosphate, aluminum phosphate, etc.),
fluorinated polymers, and silicone-based polymers. Further, the
materials disclosed in U.S. Pat. Nos. 5,616,532, 5,849,200, and
5,854,169, the entire teachings of each of which are incorporated
herein by reference, are anticipated to be useful components of the
present durable glazing compound 170.
[0100] Fluorinated polymers and silicone-based polymers are
expected to be particularly advantageous when it is intended to
maximize the adhesion strength of the durable glazing compound 170.
Further, fluorinated polymers comprising primarily
vinylether-fluoroolefin copolymers and vinylester-fluoroolefin
copolymers may be preferred, as they tend to be easy to handle and
perhaps even less susceptible to decomposition and degradation. In
most cases, it will be preferable to form the durable glazing
compound 170 of material that offers minimal permeability to water.
Materials displaying this property include, but are not limited to,
metals, polymers, ceramics, glasses, composites, and combinations
thereof. Of these, polymers (particularly those listed above) are
preferred.
[0101] While preferred embodiments of the present invention have
been described, it should be understood that various changes,
adaptations and modifications may be made therein without departing
from the spirit of the invention and the scope of the appended
claims.
* * * * *