Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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CA 02088063 2002-11-25 ~''
COATING COMPOSITION AND METHODS OF USE
TECHNICAL FIELD
The present invention relates generally to coatings used to protect glass and
glass-like
surfaces (e.g., glazed ceramic or polished or plated metal) from paint or
similar treatments.
More specifically, the present invention relates to a cohesive coating having
a high
adhesion to non-glass surfaces and a low adhesion to glass or glass-like
surfaces so that
once dry, the coating may be pulled off the glass or glass-like surface in a
continuous strip.
BACKGROUND ART
When painting window frame and trim materials there
is always the attendant problem of keeping the paint off
the glass, while at the same time in order to protect the
frame or trim from moisture, sealing the juncture between
the trim and the glass with paint. Normally, the paint is
applied in a narrow band on the glass surface adjacent tothe
trim, but this method can be difficult and time-consuming,
rec_ruiring an inordinate painting skill. Another less
exacting method involves painting along the trim-glass
junction, sometimes onto the glass, sometimes shy of the
glass. While this method may be faster than the previous
method, it leaves the trim-glass juncture in an unsealed
state. In such cases rain water or indoor condensation
will seep into the unprotected interface and eventually
cause destruction of the trim materials by rotting or
cracking. Also the old paint at the interface will be
dried and cracked, thus allowing moisture to seep in at
the interface and eventually lift the putty away from the
glass to enhance further water penetration.
Still other methods include painting at will on the
glass surface or window pane while painting the trim. A
scraper or razor blade must then be used to remove the
paint. Ordinary latex paint can be scraped off within
hours after being applied, but after that short period it
will adhere to the glass strongly. When dry, ordinary
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CA 02088063 2002-11-25
r v
paint is not a particularly "cohesive" coating and, as
such, will then break up, or fracture, when subjected to
the sheer forces of the scraper. -When paint dries too
thoroughly, it must be removed in small pieces, a time-
consuming task which often damages the glass.
Yet another method involves masking. With masking,
an adhesive coating or tape is placed on the window pane,
prior to installation or after installation, so that the
trim or frame material can be painted quickly and without
regard to the juncture between glass and trim since any
excess paint will be applied to the protective coating.
This method, however, again requires the time-consuming
operation of carefully applying the adhesive coating so
that it lines up with and abuts the glass-trim juncture.
To summarize the drawbacks of the above-mentioned
methods for protecting window pane glass during a trim or
frame painting operation, it will be seen that a high
labour commitment is required, involving increased expense,
or in the absence of skilled labor, sloppy work in the
form of uneven edges of paint residue along the trim-glass
interface or juncture, especially after spray painting
(and including.concrete splatter on the window glass
during new construction), or in the case of applying a
protective coating for the glass, the time consuming step
of applying masking tape or other protective adhesive
coating to square up exactly with the glass-trim
interface, in which case paint can be drawn under the edge
of the tape or coating at the interface by capillary
action. -
DESCRIPTION OF THE INVENTION
Accordingly it is an object of a first aspect of the present invention to
provide an
improved masking composition.
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CA 02088063 2002-11-25
An object of a second aspect of the present invention is to~provide a masking
composition that can be applied.using conventional paint application
techniques.
An object of a third aspect of the present invention is to provide a cohesive
protective
coating which may be applied to glass and non-glass surfaces, e.g., window
panes and trim
prior to painting, and after painting will adhere to the trim but will lift
easily off the glass
leaving the glass paint free.
An object of a fourth aspect of the present invention is to provide a
protective coating
which is easily and quickly applied to window trim and the adjacent window
pane before
painting and is easily removed from the glass after painting.
An object of a fifth aspect of the present invention is to provide a
protective coating
which is highly cohesive in that it does not break up, or fracture, when
subjected to the
shear forces of pulling or scraping the coating off glass-like surfaces.
An object of a sixth aspect of the present invention is to provide a
protective coating
which, when applied to window trim and abutting adjacent window panes, remains
supple
and easily removable from the glass for a sufficient amount of time after
application to
allow for delays in applying paint or other treatments to the window trim.
An object of a seventh aspect of the present invention is to provide a
protective
coating which, when applied to non-glass surfaces, may be painted with most
paints,
including both alkyd and latex paints, and which will adhere strongly to the
non-glass
surface.
An object of an eighth aspect is to provide a protective coating which, when
applied
to window trim and abutting adjacent window panes, will seal the trim-glass
juncture.
An object of a ninth aspect of the present invention is to provide a
protective coating
which can be applied efficiently by relatively unskilled labourers and will
still produce
professional-looking results when painting non-glass surfaces which are
abutting and
adjacent to glass surfaces.
An object of a tenth aspect of the present invention is to provide a
protective coating
which can be applied to glass and which can also be used temporarily to
display indicia,
e.g., the glass manufacturer's logo, installation instructions, and the like.
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CA 02088063 2002-11-25
An object of an eleventh aspect of the present invention is-to provide a
protective
coating which may itself be used as a paint on any material which is adjacent
to, and
abutting, a glass-like surface.
An object of a twelfth aspect of the present invention is to provide an
improved
method for applying paint to non-glass materials which are adjacent to, and
abutting, glass
surfaces.
An object of a thirteenth aspect of the present invention is to provide a
protective
coating which has application to a DAC (differential adhesion composition)
coating product
and which may be used to coat any dissimilar and juxtaposed surfaces, where
one is a
surface to be treated, e.g., a non-glass surface whether painted or not, and
the other is a
glass or glazed ceramic surface.
A first broad aspect of the present invention provides a method for
temporarily masking
a glass-like surface which is adjacent to, and abutting, a non-glass material
for relatively-
permanently coating the non-glass material with a differential adhesion
coating composition
while temporarily coating the glass-like surface with the differential
adhesion coating
composition. The method includes applying the differential adhesion coating
composition to
the non-glass material and to an area of the glass-like surface which is
adjacent to, and
abutting, the non-glass material. The differential adhesion coating
composition has a
relatively-high adhesion to the non-glass material and a relatively-low
adhesion to the glass-
like surface when dried. The method includes allowing the differential
adhesion coating
composition to dry. The method includes lifting the dried differential
adhesion coating
composition only from the glass-like surface.
A second broad aspect of the present invention provides a method for painting
a non-
glass material which resides adjacent to, and abutting, a glass surface. The
method includes
the step of applying a differential adhesion liquid coating composition to the
surface of the
non-glass material proximate and abutting the glass surface and at least to a
portion of the
glass surface. The differential adhesion coating composition, when dried, has
a high enough
adhesion to the non-glass material to be a relatively-permanent coating
thereon, and a low
enough adhesion to the glass surface to be removable therefrom. The method
includes
allowing the differential adhesion liquid coating composition to dry to
produce a dried
differential adhesion coating composition, The method includes painting at
least the non-
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CA 02088063 2002-11-25
glass material, including portions having the dried differential adhesion
coating composition
thereon. The method includes lifting and removing the dried coating
composition only away
from the glass surface. ~~
By a first variant of these first and second broad aspects of the present
invention, the
step of applying the differential adhesion coating composition comprises
applying the
differential adhesion coating composition for a sufficient width on the glass-
like or glass
surface to serve as a mask over the glass-like or glass surface.
By a second variant of these first and second broad aspects of the present
invention,
and/or the first variant thereof, the method includes providing an edge
between the non-glass
material and the glass-like or glass surface, and then carrying out the
lifting step by the step
of separating the dried differential adhesion coating composition from itself
along the edge so
that the dried differential adhesion coating composition remains applied to
the portion of the
non-glass material.
By a third variant of these first and second broad aspects of the present
invention,
and/or the first variant thereof, the method includes providing an edge
between the non-glass
material and the glass-like or glass surface, and cutting a line on the dried
differential
adhesion coating composition proximate the edge prior to the lifting step,
thereby to guide the
separation of the dried differential adhesion coating composition from itself
along the line so
that the dried differential adhesion coating composition remains applied to
the portion of the
non-glass material.
By a fourth variant of these first and second broad aspects of the present
invention,
and/or the first variants thereof, the method includes the step of waiting at
least one day
between the allowing step and the lifting step. By a variation thereof, the
lifting step is carned
out at any time up to one month after the allowing step.
By a fifth variant of these first and second broad aspects of the present
invention, and/or
the first variants thereof, the lifting step is accomplished by scraping the
dried differential
adhesion coating composition off of the glass-like or glass surface.
By a sixth variant of these first and second broad aspects of the present
invention,
and/or the first variants thereof, the method includes carrying out the
lifting step by exerting a
tensile stress on the dried differential adhesion coating composition and
previously having
formulated the differential adhesion coating composition so that, after the
allowing step,
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CA 02088063 2002-11-25
cohesive forces of the dried differential adhesion coating composition that
resist the tensile
stress are greater than adhesive forces between the dried differential
adhesion coating
composition and the glass surface. " - -
By a seventh variant of these first and second broad aspects of the present
invention,
and/or the first variants thereof, the method includes carrying out the
lifting step by exerting a
tensile stress on the dried differential adhesion coating composition and
previously having
formulated the differential adhesion coating composition so that, after the
allowing step,
cohesive forces of the dried differential adhesion coating composition that
resist the tensile
stress are less than adhesive forces between the dried differential adhesion
coating
composition and the glass surface.
By an eighth carrying out the lifting step by exerting a tensile stress on the
dried
differential adhesion coating composition and previously having formulated
carrying out the
lifting step by exerting a shear stress on the differential adhesion coating
composition and
previously having formulated the differential adhesion coating composition so
that, after the
differential adhesion coating composition dries, cohesive forces of the
coating composition
that resist shear stress are greater than adhesive forces between the coating
composition and
the glass surface.
By a variation of the sixth and seventh variants described above, the step of
having
formulated the differential adhesion coating composition comprises formulating
the
differential adhesion coating composition to include a resin emulsion.
. By an eighth variant of the second broad aspect of the present invention,
and/or the
above variants thereof, the painting step comprises the step of applying a
paint so that the
paint overlies the dried differential adhesion coating composition on the
glass-like or glass
surface and on the non-glass material.
A third broad aspect of the present invention provides a differential adhesion
coating
composition for use in applying a temporary mask to a glass surface which
resides adjacent
to, and abutting, a non-glass material. The differential adhesion coating
composition includes
a resin emulsion, and a wet edge agent. The differential adhesion coating
composition has
been formulated to have a relatively-high adhesion to the non-glass material.
and a relatively-
low adhesion to the glass-like or glass surface, when dried. Thus, when dried,
the differential
adhesion coating composition may be lifted away from only the glass-like or
glass surface.
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CA 02088063 2002-11-25
By a first variant of this third broad aspect of the present i-nvention,
proportions of the
resin emulsion and wet-edge agent are so selected that, after drying, cohesive
forces of the
dried differential adhesion coating composition that resist the (ensile stress
are greater than --
adhesive forces between the dried differential adhesion coating composition
and the glass-
like or glass surface.
By a second variant of this third broad aspect of the present invention,
proportions of
the resin emulsion and wet-edge agent are so selected that, after drying,
cohesive forces of the
dried differential adhesion coating composition that resist the tensile stress
are less than
adhesive forces between the dried differential adhesion coating composition
and the glass-
like or glass surface.
By a third variant of this third broad aspect of the present invention,
proportions of the
resin emulsion are the wet-edge agents are so selected that cohesive forces of
the coating
composition that resist shear stress are greater than adhesive forces between
the coating
composition and the glass-like or glass surface.
By a fourth variant of this third broad aspect of the present invention,
and/or the above
variants thereof, proportions of the resin emulsion and wet-edge agent are so
selected that the
relative strengths of cohesive and adhesive forces are maintained for at least
one day after the
differential adhesion composition dries.
By a fifth variant of this third broad aspect of the present invention, and/or
the above
variants thereof, proportions of the resin emulsion and wet-edge agent are so
selected that the
relative strengths of cohesive and adhesive forces are maintained for at least
one month after
the differential adhesion composition dries.
By a sixth variant of this third broad aspect of the present invention, and/or
the above
variants thereof, for a given weight of the resin emulsion, the wet-edge agent
is present in a
quantity of 1 % to 4% of the given weight. By a variation thereof, the resin
emulsion is an
acrylic resin, the wet-edge agent includes a glycerol, and the composition
additionally
comprises a defoaming agent and a preservative agent.
A fourth broad aspect of the present invention provides a method of making a
differential adhesion. The method includes the step of adding, to an ordinary
latex paint
formulation, a compatible, water-soluble, hygroscopic agent which remains in
the paint in
sufficient quantity consistently to produce a differential adhesion effect for
at least 30 days
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CA 02088063 2002-11-25
after the composition has dried on surfaces. The differential adhesion effect
is defined as
being high enough adhesion to a non-glass material to be a relatively-
permanent coating
thereon and a low enough adhesion to a glass-like or glass surface to be
removed therefrorri. --
By a first variant of this fourth broad aspect of the present invention, the
method
includes the step of selecting glycerol as the hygroscopic agent.
By a second variant of this fourth broad aspect of the present invention,
and/or the
above first variant thereof, the ordinary latex paint formulation includes a
resin, and the
method additionally includes the step of using the glycerol in a proportion
which is at least
10% by weight of the resin within the paint.
A fifth broad aspect of the present invention provides a method for painting a
non-glass
material which resides adjacent to, and abuts a glass-like or a glass surface
without ultimately
painting the glass-like or glass surface. The method includes the step of
applying a
differential adhesion liquid coating composition to a non-glass material which
is proximate
to, and abuts, the g lass-like or glass material and at least to a portion of
the glass-like or glass
surface abutting the non-glass material, the coating composition having
relatively low
adhesion to glass surfaces and relatively high adhesion to non-glass material
when dried. The
method includes allowing the differential adhesion coating composition to dry.
The method
includes painting at least the non-glass material, including portions having
the dried
differential adhesion coating composition thereon. The method includes lifting
and removing
the dried differential adhesion coating composition only away from the glass
surface.
DESCRIPTION OF THE FIGURES
In the accompanying drawings,
FIGURE 1 shows a front view of a window with trim;
FIGURE 2 shows the window of FIGURE 1 after a differential adhesive
composition
(DAC) coating of an embodiment of an aspect of the present invention has been
applied
according to another embodiment of an aspect of the present invention;
FIGURE 3 shows the window after the trim and underlying DAC coating of an
embodiment of an aspect of the present invention have been painted according
to another
embodiment of an aspect of the present invention;
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CA 02088063 2002-11-25
FIGURE 4 illustrates the use of a scribe or razor blade to mark a tear line
for use in
lifting the DAC coating of an embodiment of an aspect of the present invention
off the glass
according to another embodiment of an aspect of the present invention; and
FIGURE 5 shows the painted trim clean glass, and removal of the last
continuous strip
of the DAC coating of an embodiment of an aspect of the present invention,
according to
another embodiment of an aspect of the present invention.
AT LEAST ONE MODE FOR CARRYING OUT THE INVENTION
Following is a first example of the coating composition of an embodiment of an
aspect
of the present invention exhibiting differential adhesion properties:
Example 1
Materials Parts by weight
Acrylic Emulsion (Rohm & Haas ML-
200TM).......................................................................77
.1
Defoamer (Ross FOAMBLASTTM
384e)..........................................................................
....._D_1
Preservative (BUSANTM
102..4)........................................................................
.......................Ø1
Stabilizer and wet-edge agent
(propylene
glycol)........................................................................
........2_8
(glycerol).....................................................................
.....................Ø8
Coalescent (Tennessee Eastman
TEXANOLT"'.)..................................................2.2
Cellulose Thickener (Hercules HBRTM 1.5 % ). . . .. .. . .. .. . . .. .. . . .
. . . . .. . . .. .. .. . .. . . .. . . . .. . . . . 16.1
Associate Thickener
(Rohm & Haas ACRYSOL RM-825T"" 25 % ). .. . . . . . .. .. .. .. .. .. . . . .
.. . .. ....... ........... 0.8
Following are further examples of the differential adhesive composition (DAC)
coating according to an embodiment of aspect of the present invention:
Example 2
Materials Parts by weight
Acrylic Emulsion (Rohm & Haas
AC707TM)......................................................................1
07.1
Associate Thickener (Rohm & Haas
RM1020"~)...................................................................3.5
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CA 02088063 2002-11-25
Preservative (Cosan Chemical 234TM
)..............................................................................
.....Ø4
Coalescent (Tennessee Eastman
TEXANOLTM)....................................................3.4
UV Absorber (Ciba-Geigy TINUVINTM
1130).......:..:.'...................................:...:_T:0
Stabilizer (propylene
glycol).:......................................................................
...3.0
Antifoam (Dow Corning H-
lOTM)....................................................................Ø3
Associate Thickener (Rohm & Haas
TT165TM)......................................................................
1.0
Water..........................................................................
..........................................................._10.0
Example 3
Materials Parts by weight
Acrylic emulsion/resin emulsion
(Rohm & Haas AC707Tn''/AC235T"''
1:1.vut_).............................................428.0
Associate Thickener (Union Carbide SCT 270TH' 10%
)......................................... 7.0
Preservative (Cosan Chemical 234TM )...........................
......................................................1.6
Coalescent (Tennessee Eastman TEXANOLTM) . . . . .. . ... . .. . . . . . . . .
. .. .. .. . . . .. . . . .. . .. . . . . . . .. . . .7.1
UV Absorber (Ciba-Geigy TINUVINTM 1130)
............................................:.......2.9
pH Adjustment
(NHOH).........................................................................
....10.0
Stabilizer (propylene glycol)
.........................................................................4.0
Stabilizer (ethylene glycol)
.........................................................................4.0
Defoamer (Daniel Products DF8815T"') .. . . . . .. . .. .. .. . .. . . . ... .
.. . . . ... . . . . . . . . . .. .. . . . .. .. .. .. .. . .1.0
Associate Thickener (Rohm & Haas
RM1020TM)............................................... 14.0
Example 4
Materials Parts by weight
Acrylic Emulsion (Rohm & Haas
AC235TM)....................................................................:.1
07.0
Associate Thickener (Rohm & Haas
RM1O2OTM)..............................................~...~~~..~~~...~.~~~~
1.0
Associate Thickener (Rohm & Haas
RM825TM)....................................................................2.0
Preservative (Cosan Chemical 234TM
)..............................................................................
.....Ø4
Coalescent (Tennessee Eastman
TEXANOLTM.).................................................................._.
2.4
TM
UV Absorber (Ciba-Geigy TINUVIN
1130).......................................................................1.0
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!' CA 02088063 2002-11-25
Ph Adj ustment (NH OH)
...............................................................................
..........................4.0
Stabilizer (propylene
glycol)........................................................................
.......................... 3.5
In each of the above-listed examples, the composition of the coating according
to an
embodiment of an aspect of the invention is the environmentally acceptable. A
less
expensive version of the formulation can be created by increasing the amount
of water in
the formulation. In that case, more thickener may be needed. This inexpensive
formulation
will take more time to dry. Also, a less expensive resin may be used.
Some of the resin families that may be used with the composition of an
embodiment
of an aspect of the present invention include: acrylic resins; polyvinyl
acetates; and alkyd
resins. Some acrylic emulsion vehicles for the DAC (differential adhesion
composition)
coating according to an aspect of the present invention are sufficient of
themselves to act as
differential adhesive coatings exhibiting the properties of having low
adhesion to glass and
high adhesion to wood, baked enamels and painted surfaces, and certain metals
and
plastics.
For the purpose of aspects of the present invention, namely to provide a
protective
coating for window glass during a painting operation performed on the trim
adjacent to,
and abutting, the glass, the effectiveness of the acrylic emulsion is enhanced
by the
addition of the above-described materials. For example, the thickener agent
improves the
strength of the coating. The coalescing agent serves to bind the resin
particles or
ingredients of the composition of an aspect of the present invention, that is,
binds or
"glues" the microscopic resin particles together as the coating composition
from decay in
the container and as a film when applied. The wet-edge agent, namely, the
glycol and
glycerol component, not only enhances uniform application of the coating
composition
when it is applied to the work surface but it also helps ease the liftability
of the DAC
coating composition of an aspect of the present invention under varying
conditions of
temperature and humidity. Glycerol and various glycols serve as hygroscopic
agents. In
one preferred embodiment, about 1 to 4 parts of coalescing agent and about 1
to 4 parts of
wet-edge agent are utilized for each 100 parts of resin emulsion.
The capacity of hygroscopic agents to absorb and retain moisture or water is
believed
to have a significant influence over the differential adhesion effect. It is
believed that some
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CA 02088063 2002-11-25
resin emulsions as supplied by the manufacturer have sufficient differential
adhesion
characteristics to work as a differential adhesion composition alone. The
differential
adhesion effect appears to come in part from the retention of higher-than-
normal levels of
moisture in the coating over relatively long periods. A loss of moisture in
the coating
results in a reduction in liftability. However, by the use of a very powerful
hygroscopic
agent, the water can be retained in the DAC coating of an aspect of the
present invention
even during the most adverse ambient conditions. The same effect may be
produced to a
lesser extent by using larger quantities of less hygroscopic additives. In a
preferred
embodiment of an aspect of the present invention, the differential adhesion
characteristics
of the DAC coating of an aspect of the present invention persist for longer
than one day
and preferably at least 30 to 60 days after application. This length of time
allows for
ordinary, and even extraordinary, delays in completing a painting job.
The DAC coating of an aspect of the present invention can be made as shown in
Examples 2 and 3 by the use of propylene glycol and/or ethylene glycol. These
hygroscopic agents are formulated into ordinary paint for other reasons than
achieving the
differential adhesion characteristics of an aspect of the present invention
and at much
higher percentages than in the differential adhesion coating formulations.
Yet, ordinary
paint can only be scraped with relative ease during a very short time after
application,
generally less than 24 hours, depending on the specific formulation of the
paint and the
ambient temperature, humidity, and other factors. It is believed that this
difference between
the DAC coating of an aspect of the present invention and ordinary paint may
be caused by
the pigment in the paint. The pigments may tend to absorb the ethylene glycol,
propylene
glycol, and other hygroscopic agents, reducing their effectiveness.
Regardless,
conventional paints are unsuitable as differential adhesion coatings.
The suggested hygroscopic agents are the glycols, glycerol, and CARBITOLTM
solvent, and hygroscopic agents as shown in Table 1. However, any hygroscopic
agent is a
candidate. Glycerol is the preferred candidate since it absorbs and retains a
very high
percentage of moisture for an extended period of time, as shown in Table 2.
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Table 1
Hyaroscopic A eats - ----
Only a few chemical categories account for the
major hygroscopic agents. These are:
(1) Quaternary ammonium compounds,
(2) Amine derivatives,
(3) Phosphate esters,
( 4 ) Derivatives of polyhydric alcohols, e-g.,
(a) Sorbitol, and
(b) Glycerine,
(5) Polyglycol esters of fatty acids, and
( 6 ) Glycols, e.g.,
(a) Ethylene glycol,
(b) Diethylene glycol,
(c) Triethylene glycol,
(d) Propylene glycol,
(e) Dipropylene glycol, and
(f) Tripropylene glycol.
fable 2
Hygroscopicity of 99.5%-purity Glycerine
,fit 50% Relative Humiditv
Percentage Weig ht Increase
Hour ~, 70'F(21'C) ~"'77'F(25'C)
5 4
7 5
8 7
10 8
12 8
75 13 10
100 14 11
150 17 13
200 17 14
The preferred hygroscopic agents used to provide the DAC of aspects of the
present
invention generally have the following characteristics: 1) water soluble; 2)
liquid between
temperatures of 30° F (-1° C) and 150°F (66°C); 3)
low in vapour pressure; 4) high flash
point; 5) low evaporation rate; 6) low toxicity; 7) commercially available at
reasonable
cost; 8) non-corrosive; and 9) stable at the pH of the coating.
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CA 02088063 2002-11-25
FIGURES 1 to 4 illustrate a method of painting in accordance with an aspect of
the
present invention. FIGURE 1 illustrates a window 10 having glass panes 12 and
window
trim or frame 14. FIGURE 1 depicts the state of window IO prior to beginning a
painting
operation. In other words, glass panes 12 are relatively free of paint and
other foreign
substances, and frame 14 is in need of painting.
FIGURE 2 shows window 10 after application of a DAC coating 16 of an aspect of
the present invention, prepared in accordance with above-discussed teaching of
the method
of an aspect of the present invention and applied according to another aspect
of the present
invention. DAC coating 16 of an aspect of the present invention may be
brushed, wiped,
rolled, or sprayed on the work surfaces to be treated. In the case of
brushing, DAC coating
16 of an aspect of the present invention may be applied directly to trim 14
with the excess
spilling over onto glass 12 as shown in FIGURE 2. Preferably, this excess is
of sufficient
width to serve as a paint mask for glass 12 as the trim 14 is being painted.
A second version (not shown) involves applying DAC coating 16 an aspect of the
present invention on glass 12 at the juncture between the wood 14 (or other
non-glass
material) and glass 12, in order to mask or protect glass 12 new window trim
14. In this
method, naturally some of DAC coating 16 of an aspect of the present invention
will ride
up onto widow frame 14 as it is being applied go glass 12, especially if it is
being applied
quickly, which is desirable, and by an unskilled hand.
A third version (not shown) of applying DAC coating 16 of an aspect of the
present
invention is preferably utilized when spray painting or other types of wide-
spread splatter
are anticipated. In the third version, DAC coating 16 of an aspect of the
present invention
is applied over the entire exposed surface of glass 12.
Because of the differential adhesion properties, DAC coating 16 of an aspect
of the
present invention will adhere well to window frame 14, the same as ordinary
paint will,
while at the same time adhering in a dramatically different way to glass 12 by
selectively
adhering to glass 12. DAC coating 16 of an aspect of the present invention
adheres firmly
to glass 12, exhibiting at the same time low tensile adhesion, or low
resistance to tensile
forces, much as a removable sticky label adheres to any surface.
Once DAC coating I6 of an aspect of the present invention is applied and
covers a
suitably wide strip of glass 12 adjacent window trim 14, and once it sets up
or otherwise
14
CA 02088063 2002-11-25 !'
_ becomes coatable, normally within three hours after application, the
painting operation on
trim 14 can begin. FIGURE 3 shows window 10 after a paint 18 or other covering
composition is applied according to an aspect of the present invention. As a
surface to be4~
painted, DAC coating 16 of an aspect of the present invention readily accepts
both alkyd
and latex paints. Painting can commence without regard to keeping paint 18 off
glass 12,
since any paint 18 that may ride over onto glass 12 will ride onto DAC coating
16.
Referring to FIGURES 4 and 5, after painting is complete and paint 18 is dry,
DAC
coating 16 of an aspect of the present invention on glass 12 may be lifted off
in an
essentially continuous strip or sheet, together with any overlay of paint 18
thereon. For the
purposes of an aspect of the present invention, lifting is defined as a sheet-
like removal
either by peeling or by scraping, as opposed to, and distinguished from,
chipping, in which
the material is removed in flakes or granules. If, after the first step of
applying DAC
coating 16 of an aspect of the present invention to glass 12 is initiated, the
painting
operation is delayed for some reason, the preferred embodiment of DAC coating
16 of an
aspect of the present invention may be left on glass 12 for a reasonably long
time. Coating
16 may be left on glass 12 for about a month under outdoor conditions and up
to four
months under indoor conditions before it becomes necessary to paint trim 14
and remove
DAC coating 16 of an aspect of the present invention.
It is preferable, but optional, to cut, scratch, or otherwise scribe a line 20
in DAC
coating 16 of an aspect of the present invention along the juncture or edge of
trim I4 and
glass 12 with a knife 22, razor blade, or the like (see FIGURE 4) prior to
lifting the dried
DAC coating 16 of an aspect of the present invention away from glass 12.
Scribe Iine 20
insures that DAC coating 16 of an aspect of the present invention may be
separated from
itself in a controlled manner and at desired locations. If a very sharp
object, e.g., a razor
blade, is used to form scribe line 20, blade surface is preferably held at
about 30 degrees to
the plane of glass 12 for best results. In this way, the blade 22 doesn't
scratch glass 12 as it
might if it were held normal to glass 12. The dried DAC coating 16 of an
aspect of the
present invention can be lifted off the glass surface by peeling or scraping.
Depending on
the coating formulation, the dried DAC coating 16 of an aspect of the present
invention
may break into many pieces during scraping. By scraping is meant the process
of removal
using a razor blade in which the coating is easily lifted as opposed to being
removed by
i i
CA 02088063 2002-11-25
_ substantial force.
Next, dried DAC coating 16 of an aspect of the present invention is simply
lifted
away from glass 12. Due to the difference in adhesion between dried DAC
coating 16 and
glass 12, on one hand, and between dried DAC coating 16 of an aspect of the
present
invention and trim 14, on the other hand, dried DAC coating 16 of an aspect of
the present
invention peels or otherwise lifts easily. The mechanism whereby the product
of an
embodiment of an aspect of the present invention exhibits this selective or
differential
adhesion is believed to be present in the aspect of the present invention
between the dried
DAC coating 16 of an aspect of the present invention and the type of surface
to which it is
applied.
In addition, dried DAC coating 16 of an aspect of the present invention has
strong
cohesive properties, which means that dried DAC coating 16 of an aspect of the
present
invention tends to stick to itself. When subjected to the shear stresses that
result from
peeling, pulling, or scraping, of the dried DAC coating 16 of an aspect of the
present
invention off glass 12, the cohesive forces of dried DAC coating 16 of an
aspect of the
present invention are greater than the adhesive forces between dried DAC
coating 16 of an
aspect of the present invention and glass 12. Consequently, dried DAC coating
16 of an
aspect of the present invention separates from glass 12 while cohesively
sticking to itself.
In other words, in the presence of a shear stress in dried DAC coating 16 of
an aspect of
the present invention tends to separate from glass 12 before it fractures or
otherwise
separates from itself. Moreover, this strong cohesive property relative to low
glass
adhesion persists for a couple of months, as discussed above.
On the other hand, once DAC coating 16 of an aspect of the present invention
dries
or otherwise becomes coatable, it adheres to non-glass materials, e. g. ,
frame 14, much
more strongly than it adheres to glass 12. The forces applied due to cohesive
properties of
dried DAC coating 16 of an aspect of the present invention are less than
forces applied due
to the non-glass adhesive property. Thus, dried DAC coating 16 of an aspect of
the present
invention tends to separate from itself rather than separate from frame 14.
Scribe line 20 guides this separation. On the other hand, scribe line 20 may
be
omitted. When scribe line 20 is omitted, dried DAC coating 16 of an aspect of
the present
invention is simply lifted off glass 12 once a corner or tab is created. Trim
or frame 14 of
16
.. . . ~....,.I.. , i FI
CA 02088063 2002-11-25
window 10 then acts acceptably well in many applications as a straight edge
for severing
dried DAC coating 16 of an aspect of the present invention from its
counterpart on trim 14.
After dried DAC coating 16 of an aspect of the present invention has been
completely
removed from glass 12, the painting job is complete for the purposes of an
embodiment of
the present invention. Glass 12 is substantially-free of paint. At least a
portion of trim 14
may be covered with dried DAC coating 16 of an aspect of the present invention
and paint
18.
The above-discussed preferred embodiment of the DAC coating 16 of an aspect of
the
present invention is a generally-transparent composition. A dye or pigment can
be
introduced into this DAC coating 16 of an aspect of the present invention in
order to give it
colour or opacity if such is desirable. However, a clear coating functions as
well as a
coloured one for the above-discussed glass protection purposes.
In the case of using the DAC coating 16 of an aspect of the present invention
with
new windows, the manufacturer's logo, directions etc. may advantageously be
printed on
the DAC coating 16 of an aspect of the present invention once it is applied to
the glass. In
this way, the coating might bear the glass manufacturer's name or a particular
paint
company's name, or the name of a manufacturer or service company that might be
instrumental in the installation and painting of windows, glass doors and the
like. Such
temporary indicia as logos, directions, etc. may be applied onto the coating
by well known
methods, e.g., silk screen, printing, stamping, etc.; or the same indicia
could be affixed to
a carrier e.g., paper or film and the carrier could then be applied to the DAC
coating 16 of
an aspect of the present invention by any suitable method. In some cases, the
indicia could
be cut away from the coating in areas where there would be no possibility of
paint coming
in contact with that part of the coating. It is conceivable, too, that the cut-
away portions of
the DAC coating 16 of an aspect of the present invention conforming to the
indicia being
represented could be filled in with a paint, or other permanent marking, that
would stay on
the glass as a logo or name if such glass were used commercially, as in a
store window or
office window or the like.
An aspect of the present invention further contemplates the use of the DAC
coating of
an aspect of the present invention itself as a paint, or painting composition.
For use as a
paint, a proper pigmentation is applied to the DAC composition of an aspect of
the present
17
CA 02088063 2002-11-25
_ invention in order to render the DAC coating of an aspect of the present
invention a
coloured paint composition of whatever colour. In one embodiment, the DAC of
an aspect
of the present invention paint is formed by adding about 4 % glycerine to
ordinary latex
paint. Testing has shown that adding about 4 % by total weight of glycerol to
an ordinary
latex paint, e.g., Benjamin Moore MOORGLOT"', will produce a differential
adhesion
paint. Preferably, the percentage of glycerol to resin is greater than about
10 % . Since there
is approximately 20% resin in MOORGLOT"' paint, the percent of glycerol to
resin in the
MOORGLOTM paint example is about 20 % .
One example of ordinary latex paint lists the following ingredients:
Resin or binders 234 lbs. 22%
Water 455 lbs. 44 %
Pigment 249 lbs. 24
%
Wet edge agent75 lbs. 7
Coalescent 12 lbs. 1
Other 17 lbs. 2
Depending on the paint and other factors, less glycerol will provide an
acceptable
product for less long periods of time. Also, adding glycerol to paint creates
a differential
adhesion coating of an aspect of the present invention that is not as strong
cohesively as the
unpigmented differential adhesion coating examples presented above. Further,
the
percentage of glycerol can be raised to make the differential adhesion effect
last longer.
Thus, it appears that a very strong and/or long lasting hygroscopic agent is
available to
create consistent differential adhesion properties. For the purposes of an
aspect of the
present invention, consistent differential adhesion indicates that the ease
with which the
coating may be removed remains relatively stable over a relatively long period
of time.
The current use of about 16 % propylene glycol and ethylene glycol in paints
alone fails to produce an acceptable differential adhesion effect. Generally,
the time
between applying a first coat of paint and completion of drying of a second or
third coat
exceeds the duration during which the first coat of paint is liftable from the
glass. In other
words, a first coat of conventional paint cannot be easily scraped from glass
if it is
sufficiently dry to support a second coat of paint. Consequently, when
multiple coats of
18
CA 02088063 2002-11-25
conventional paint are applied, the paint cannot be scraped off glass unless
each coat of
paint is separately removed before applying the next coat, a time consuming
and costly job.
However, the DAC paint of an aspect of the present invention formed as - -'--
discussed above is liftable for 30 days or more. The DAC paint is used
directly as a paint
on window frames and trim materials or on any materials that border and abut a
glass or
glass-like surface (e.g., a glazed ceramic or polished or plated metal). When
DAC paint is
being applied, the above-discussed step of first applying the DAC of an aspect
of the
present invention coating as a glass-protecting coating is unnecessary.
Rather, the DAC
paint is applied directly as a paint on window frames and the like without
regard for getting
the DAC paint of an aspect of the present invention on the glass. Once the DAC
paint of an
aspect of the present invention sets up on the glass, further coats of paint
can be added.
After the painting job is complete, the portions of the dried DAC coating on
the glass
would be removed from the glass as previously described.
The pigmented DAC paint coating, described above, may also be used as a
primer or first coat. Hence, another kind of finishing paint that is perhaps
more suitable to
the needs of the user at the time may be used over the DAC paint of an aspect
of the
present invention. Once the primer DAC paint of an aspect of the present
invention is
applied, according to the steps above described according to an embodiment of
an aspect of
the present invention, further coats of a different paint (perhaps a different
colour) can be
applied over the primer on the non-glass surface to be treated. The adjacent
glass, then,
would be protected because of the initial coat of DAC paint primer of an
aspect of the
present invention thereon, which ultimately would be lifted off the glass
together with the
subsequent coats of paint thereon.
In summary, according to aspects of the present invention, a coating
composition
is provided having differential adhesion properties when applied in a single
operation to
trim material which is to be painted without regard to covering adjacent and
abutting
window glass. The DAC (differential adhesion composition) coating of an aspect
of the
present invention is characterized by high adhesion to wood, painted surfaces
and certain
metals and plastics and at the same time by a low or selective adhesion to
glass and glass-
like surfaces, so that the dried DAC coating of an aspect of the present
invention may be
lifted off from the glass once the coating sets up or otherwise becomes
coatable (about
19
I, ; I : . hi
CA 02088063 2002-11-25
three hours after application) together with any paint overlay' thereon after
a subsequent
painting operation of the window frame is completed. As a surface to be
treated with paint,
the coating will adhere to other paints, for example, alkyd and latex paints.
In order to
remove the dried DAC coating of an aspect of the present invention, it is only
necessary to
lift an edge of the coating from the glass, as by a razor blade or other
suitable tool, to
provide a gripping area so that the coating can be removed from the glass in a
continuous
manner, similar to removing a stick-on label. The particular adhesive quality
on glass and
glass-like surfaces of the dried DAC coating of an aspect of the present
invention is
characterized by a low resistance to tensile forces, so that the dried DAC
coating of an
aspect of the present invention sticks to the glass surface once it is applied
(either by brush,
roller or spraying) but can be easily lifted away from that surface after
curing or setting-up.
The dried DAC coating of an aspect of the present invention is extremely
cohesive, causing
it to remain in a continuous strip or sheet rather than fracturing when
subjected to sheer
forces inherent in pulling or lifting the coating off the glass. The dried DAC
coating of an
aspect of the present invention can be left on the glass surface for a
reasonably long time,
about 1 to 2 months under outdoor conditions and up to about four months under
indoor
conditions, before it becomes necessary to paint the trim.
The present invention in its various aspects may be exploited by makers of
coating compositions, masking products, paints, primers, and the like. The
method of an
aspect of the present invention can be exploited by painting contractors,
homeowners,
hobbyists, or anyone needing to paint non-glass materials which are adjacent
to, and
abutting, glass-like surfaces rapidly and inexpensively. The method for adding
indicia to a
glass-like surface could be exploited by makers of glass or paint or by any
other business
or individual with an interest in temporarily displaying advertising or
instructions on glass.
