Note: Descriptions are shown in the official language in which they were submitted.
CA 02246735 1998-09-28
ANTI-GRAFFTTI CONSTRUCTION ADHESIVE COMPOSITION
FIELD OF THE INVENTION
The present invention relates to an construction adhesive composition that
once is
applied to a substrate all new unwanted graffiti can be removed by applying
any sticky tape
over the graffiti and then simply pulling the graffiti off the substrate along
with the tape and
is particularly concerned with construction adhesive composition which is
repellent against
graffiti.
to BACKGROUND OF THE INVENTION
Graffiti damage has been an increasingly growing concern. The term graffiti
has lost
it's historical meaning and has acquired a negative tone to it. Today most
people view graffiti
not as an art form but as a form of vandalism and property destruction.
Graffiti is mostly
found in institutions such as schools, public and private buildings,
automobiles, trucks, trains,
15 cars and public rest rooms and, in open areas such as support walls for
bridges, inner walls
of buildings and park structures. The vast majority of graffiti are created
with oil-based
paints including enamels, epoxies, lacquers and urethanes, which are applied
by spray cans.
Conventionally, removal of unwanted graffiti has been performed by
sandblasting the
graffiti from the substrate. However, this method is expensive and hazardous
to health due to
2o the emission of potential carcinogenic particles. Moreover, the method
causes damages to
the paint surface. No long term solutions are offered by the use of this
method and the
surface will likely be repainted with new graffiti damages.
CA 02246735 1998-09-28
Another method commonly used is by treating the substrate with chemicals. In
this
case, the chemicals often destroy the surface and, are generally hazardous as
they require
handling with highly caustic solutions.
In an attempt to overcome many of the problems associated with sandblasting
and
chemical methods, it has been common practice to apply a protective coating on
top of the
paint or to use a paint which has anti-adhesive properties against graffiti.
However, such
coatings or paints have a slow final curing time. Also, they are too soft and
is often damaged
by the paint removers which are used to remove the graffiti. Another
disadvantage is that such
coatings and paints do not age well, and with time will often become sticky
and pick up dirt.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a construction adhesive
composition
which is repellent against graffiti and which is not sacrificial.
In accordance with one aspect of the present invention, there is provided a
construction adhesive composition comprising:
(a) from about 1 to about 99.9% by volume of construction adhesive, one such
adhesive is produced by the company Lepage and sold under the name Bulldog
Adhesive, Premium PL TM
(b) once a coating of Bulldog PL Premium TM. Adhesive has been applied over
the
2o substrate, then all new unwanted graft iti can be removed by applying any
sticky
tape over the graffiti and then simply pulling the graffiti off the substrate
along
with the tape.
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Preferably, the amount of construction adhesive composition is from about 1 to
about 99.9%
by volume. The construction adhesive may be one produced by Lepage and sold
under the
name Bulldog PL Premium TM (non-paintable}.
The adhesive composition may also include additives such as LTV sunscreens,
color pigments
and liquid cement.
In accordance with another embodiment of the present invention, there is
provided a
construction adhesive composition comprising:
(a) from about 1 to about 99% by volume of a construction adhesive selected
from
the group consisting of urethane.
(b) from about 1 to about 15% by volume of xylol (mineral spirits);
(c) from about 5 to about 15% by volume of additives.
In accordance with another aspect of the present invention, there is provided
a topcoat
comprising:
(a) about 70% by volume of construction adhesive (urethane) ;
is (b) about 15% by volume of xylol (mineral spirits);
(c) about 15% by volume of a colored paint.
In accordance with another aspect of the present invention, there is provided
a cement
paste comprising:
(a} from about 1 to about 99% by volume of an adhesive selected from the group
2o consisting of urethane; and
(b) the balance comprising a liquid cement.
Preferably, the liquid cement is in an amount of 60% by volume of the total
volume of the
cement paste. The cement paste may further include from about 1 to about 15%
of xylol
(mineral spirits) and from about 5 to about 15% of additives.
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In accordance with another aspect of the present invention, there is provided
a method
for removing graffiti from a substrate comprising the steps of
{a) applying at least one layer of a primer-sealer onto the substrate;
(b) applying at least one layer of a topcoat;
(c) applying at least one layer of a clear coat comprising:
(i) from about 1 to about 99% by volume of a construction adhesive selected
from the group consisting of urethane; and
(ii) the balance comprising a clear paint.
The construction adhesive may be urethane. Preferably, the amount of
construction adhesive
1o is about 15% by volume in the topcoat and about 70% by volume in the clear
coat. The
topcoat and clear coat may further include from about 1 to about 15% by volume
of mineral
spirits and, from about 5 to 15% of additives such as liquid cement and UV
protectors.
The advantages of the construction adhesive composition of the present
invention are
that it has a quick final curing time, is not sacrificial and is safe to use
in contrast to epoxy
15 coatings.
DETAILED DESCRIPTION OF THE INVENTION
The terms "construction adhesive" as used herein refers to any fluid material
that will spread
over a solid surface and dry or harden to an adherent film; "vandalized
substrate" refers to a
2o substrate on which there are graffiti; "cleaned substrate" refers to a
substrate where graffiti
has been removed by, for example, repainting the substrate with the paint
composition of the
present invention; and "new graffiti" refers to graffiti that is applied onto
cleaned surfaces. It
will be further understood that the terms "substrate" and "surface" are used
generally
interchangeably.
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In accordance with one aspect of the present invention, there is provided a
construction adhesive composition including:
(a) from about 1 to about 99% by volume of a construction adhesive selected
from
the group consisting of urethane;
(b) about 15% by volume of xylol (mineral spirits)
(c) the balance comprising a paint;.
An example of a source construction adhesive that is used in the adhesive
composition of the present invention is product Bulldog PL Premium TM (not
paintable)
manufactured by Lepage. The construction adhesive makes the paint composition
and
to substrate repellent against graffiti.
The paint may be solvent-based, oil-based or water-based and can be clear or
can
include color pigments. An example of clear paint is the product Insl-Thane II
Industrial
Waterborne Acrylic Enamel manufactured by Insl-X Products Corporation,
StoneyPoint, NY,
USA. This product is preferred mainly because its rapid final curing time of
seven days in
Is contrast to the usual thirty days. Another advantage of the Insl-Thane
product is that it is an
industrial paint and hence, is tougher, for example it can withstand extreme
weather
conditions, and is harder, i.e. can withstand repeated cleanings, upon drying
than most
commercially available products. Therefore, the above clear paint provides a
good vehicle
for the construction adhesive.
2o A suitable colored paint, i.e. a paint which has color pigments, is a
commercially
available house paint such as Ultra High Gloss Architectural Waterborne
Acrylic Enamel
manufactured by Glidden TM
In addition to the components (a) and (b), xylol (mineral spirits) may be
added to the
paint composition in order to melt the construction adhesive .XylolTM made by
Feilding
CA 02246735 1998-09-28
Chemical Technologies TM has been found to be an efficient product for this
purpose. The
Xylol TM may be purchased at Glidden Paints ON. Canada. The preferred ratio of
construction adhesive to xylol (mineral spirits) is about 9:1.
Additives may also be incorporated in the paint composition of the present
invention.
Examples of additives are liquid cement, color pigments and UV sunscreens. A
suitable
source of liquid cement is the product Liquid Concrete Crack Filler
manufactured by U.S.E.
Hickson Products Ltd., Scarborough, ON., Canada. The liquid cement helps make
the paint
tougher and harder.
One example of a source of UV sunscreen can be found in already prepared paint
formulations such as the product Rain-Shield Clear MB by GermiteTM Product
Inc.,
Mississauga, Ontario, Canada.
The paint composition of the present invention may be used on a variety of
type of
surfaces such as masonry, wood or steel surfaces in order to remove graffiti
therefrom.
Masonry surfaces may include cements, concrete bricks, mortars, plasters and
stuccoes.
1 s Depending on the condition of the surface, pre-washing the surface may be
required.
The pre-washing may be accomplished using conventional techniques. The
substrate should
at least be washed with soap and water to remove any dirt which may affect
bonding prior to
applying the paint composition. After surface preparation, an undercoat such
as a primer-
sealer is applied to the surface to seal, prime and block out stains. Although
not required, a
2o primer-sealer undercoat is highly recommended to minimize poor and uneven
gloss, to
prevent the surface from getting dirty quickly and enhance the adhesion of the
topcoat to the
surface. In this case, the primer-sealer used is the product Aquacrylic
GripperTM from ICI
CA 02246735 1998-09-28
Paints (Canada) Inc., Concord, Ontario, Canada. Generally, two layers of
undercoat is
sufficient; however more layers may be applied.
Following the application of the undercoat, a topcoat is applied onto the
undercoat.
The topcoat is provided by the paint composition of the present invention. It
will be
appreciated by a person skilled in the art that the actual composition of the
paint composition
will depend mostly on the location of the substrate and taste of the
individual. For example,
in areas of heavy traffic, one may choose to add more construction adhesive in
order to make
the formula more repellent, and perhaps, to add liquid cement in order to
provide a hard
coating upon drying. One possible combination of ingredients to provide a
construction
to adhesive composition which can be used as a topcoat may include:
(a) from about 1 to about 70% by volume of construction adhesive
(b) from about 1 to about 15% by volume of xylol (mineral spirits);
(c) from about 5 to about 15% by volume of a liquid cement; and
(d) the balance comprising a mixture of an industrial clear paint and a
colored paint.
1 s Preferably, the topcoat includes:
(a) about 70% by volume of construction adhesive;
(b) about 15% by volume xylol (mineral spirits); and
(c) the balance comprising a mixture of an industrial clear paint and a
colored paint.
Preferably, the mixture has a ratio of clear paint to colored paint of about
1:1 Depending on
2o the surface, one or several layers of topcoat may be applied. Preferably,
at least two layers of
topcoat are applied. The topcoat is repellent against most type of markings
such as coating
of paints, varnishes, urethane shellacs and lacquers; however, it was noted
that it is not highly
repellent against magic markers. It is postulated that the magic marker binds
to the pigments
of the colored paint rending its removal difficult. Therefore, it is advisable
to include a clear
CA 02246735 1998-09-28
coat, which was found to provide good repellency against all types of
graffiti, including
magic markers. It appears that the magic marker cannot impregnate into the
clear coat.
The clear coat may include:
(a) from about 1 to about 99% by volume of construction adhesive;
{b) from about 1 to about 15% by volume of xylol (mineral spirits); and
(c) the balance including an industrial clear paint.
Preferably, the clear coat includes:
(a) about 70% by volume of construction adhesive;
(b) about I S% by volume of mineral spirits; and
(c) the balance including an industrial clear paint.
Again, liquid cement may be added to the clear coat to render the paint harder
upon drying.
It should be noted that by adding liquid cement into the clear coat, the clear
coat will have a
tint of cement color. Hence, such clear coats are preferably used on cement
substrates. One
to several layers of clear coats may be applied onto the topcoat. Generally,
in areas of high
I s traffic, two to four layers of clear coat should be applied in order to
provide adequate
protection. The clear coat also protects the topcoat from dirt and extreme
atmospheric
conditions, hence prolonging the lifetime of the topcoat. In addition, it was
noted that the
aesthetic appearance of the surface is enhanced by including the clear coat.
In another embodiment of the present invention, there is provided a cement
paste
2o which is anti-adhesive against graffiti. The cement paste includes:
(a) from about 1 to about 70% by volume of a construction adhesive selected
from
the group consisting of urethane; and
(b) the balance comprising a liquid cement.
CA 02246735 1998-09-28
The thickness of the paste can be varied by adjusting the amount of liquid
cement therein, or
by adding a clear paint. The cement paste may further include from about 1 to
about 15% by
volume of xylol (mineral spirits). Similarly to the paint composition, the
cement paste can be
used to cover unwanted graffiti.
EXAMPLE 1
CLEAR COAT
A clear paint composition was formulated by mixing 2.8 L (0.6 gallon) of
construction adhesive , 0.25 L of xylol (mineral spirits); 0.25 L of Insl-
Thane II Acrylic
1 o Enamel Borne Enamel. The ingredients were mixed at room temperature to
provide a
homogeneous mixture which was used as a clear coat.
EXAMPLE 2
1 s TOPCOAT
A paint composition was formulated by mixing 4.6 L ( 1 gallon) of the clear
paint
composition obtained from example 1 with 4.6 L ( 1 gallon) of Ultra High Gloss
Architectural
Waterborne Acrylic Enamel obtained by GliddenTM in a 23 L (5 gallons) barrel.
The paint
solution was mixed at raom temperature to provide a homogeneous mixture which
was used
2o as a topcoat.
EXAMPLE 3
CEMENT PASTE
0
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The cement paste was formulated by mixing 0.92 L of construction adhesive
;0.10 L
of mineral spirits and 0.10 L of Liquid concrete Crack Filler in a 23 L
barrel. The paste
mixture was mixed at room temperature to obtain a thick homogeneous cement
paste which
can be used to fill in deep crevices in the substrate.
The paint composition according to the invention was tested outdoors on a pre-
cast
cement wall which is exposed under various atmospheric conditions such as
direct
sunlight, shades and rain at various temperatures, or a bridge underpass.
Several samples were prepared in order to determine whether the composition
had
anti-adhesive properties against graffiti. Referring to Tables 1 and 2, two
types of surfaces
1o were used, namely cement surface exposed to air and a surface of a bridge
underpass. The
samples were prepared by various methods as shown in the tables. After the
samples were
prepared, graffiti was applied thereon and removed by applying a sticky tape
over the
newly applied graffity. At the present time upon first application of the
sticky tape, only
about 75 % of the graffity can be be removed by using sticky tape whereas by
spraying any
1 s spray adhesive such as Elmer's Spray Adhesive initially over the graffity
before applying
the sticky tape, one can remove 100 % of the graffity. At the present time, a
special more
sticky tape is being developed to overcome the added use of the spray
adhesive.
The results were rated as either poor, adequate or good. A poor result means
that
graffiti could not be successfully removed from the surface. An adequate
result signifies
2o that graffiti could be removed from the surface; however the surface may be
damaged. A
good result means that graffiti can easily be removed from the surface without
damaging
the surface, even after repeated cleanings.
,"
CA 02246735 1998-09-28
Table 1: Results from the
anti-adhesive test carried
on a cement surface.
Sample 1 Sample 2 Sample Sample 4 m le 5 Sample
3 6
1 primer- pre- pre- pre- pre- pre-
Time sealer washed washed washed washed washed
(months) 2 1 clear 1 primer- 1 primer- 1 cement
topcoats coat sealer sealer paste
2 topcoats 2 topcoats
2 clear
coats
1 adequate poor poor good adequate good
2 adequate poor poor good adequate good
3 ade uate oor oor ood ad uate ood
Table 2: Results from the anti-adhesive test carried out on a surface located
under a bridge.
Sample 7 Sample Sample Sample Sample Sample
8 9 10 11 12
1 primer- pre- pre- pre- pre- pre-
Time sealer washed washed washed washed washed
(months) . 2 1 clear 1 primer- 1 primer- i cement
topcoats coat sealer sealer paste
2 topcoats2 topcoats
2 clear
coats
1 adequate poor poor good adequate good
2 adequate poor poor good adequate good
3 ad uate oor oor ood ade uate ood
Samples 1 and 7 were prepared by applying one layer of undercoat having a
thickness of about 4 MILS 100 Microns/ Dry 2 MILS SO Microns, with a roller.
The
undercoat was allowed to dry for 30 minutes. It was found that after 30
minutes the
applied primer-sealer coat was dry to the touch.
The preparation of samples 2 and 8 included cleaning the surfaces with a broom
to and applying a 4.0 MILS 100 Microns/Dry 1.5 MILS 37.5 Microns thick
topcoat. The
topcoat was allowed to dry for one hour, following which a second topcoat was
applied.
The second topcoat was allowed to dry for six hours prior to the application
of graffiti.
CA 02246735 1998-09-28
The preparation of samples 3 and 9 included cleaning the surfaces with a broom
and a clear coat was applied and allowed to dry for one hour.
The preparation of samples 4 and 10 included pre-washing the surfaces with a
broom and applying a 4 MILS 100 Microns/ Dry 2 MILS 50 Microns thick of
undercoat
primer-sealer. The undercoat was allowed to dry for thirty minutes and a 4
MILS 100
Microns/ Dry 2 MILS 50 Microns thick topcoat was applied. A second topcoat was
applied and allowed to dry for six hours. A clear coat was applied and allowed
to dry for
one hour. A second clear coat was applied and allowed to dry. Graffiti was
applied.
The preparation of samples 5 and 11 included pre-cleaning the surfaces with a
1o broom. The surfaces were coated with a 4 MILS 100 Microns/ Dry 2 MILS 50
Microns
thick of primer-sealer. The primer-sealer was left to dry for thirty minutes.
A topcoat of
about the same thickness as that of the undercoat was applied and allowed to
dry. A
second topcoat was applied and allowed to dry. Graffiti was applied.
The preparation of samples 6 and 12 included pre-washing the surfaces and
1 s applying a layer of cement paste. Graffiti was applied.
All of the above sample testing were carned out as accurately as possible. A
new
roller and separate clean gallon container was used for each and every new
sample site,
taking great care as not to contaminate them. A broom was used to remove
accumulated dirt
and dust on the samples after 10, 20, 30, 60, 90 days respectively.
2o Samples 4, 6, 10 and 12 showed the best results. In these cases, the
topcoats, clear
coats and cement coats adhered extremely well to the substrate. Graffiti could
be repeadably
removed from the cleaned surfaces without damaging them and, posters did not
adhere well
onto the cleaned surfaces either.
CA 02246735 1998-09-28
Samples 1 and 7 gave adequate results. This may be due to the fact that there
was
only one thick coat of primer-sealer and hence, may not have had enough paint
thickness to
withstand repeated cleanings of graffiti. It may also be that the outer skin
of the undercoat is
too soft to withstand repeated cleanings.
Samples 2 and 8 gave poor results, even worse that of samples 1 and 7. It
seems
that the topcoat gave good protection against graffiti; however, the topcoat
did not adhere
well to the substrate, and would be damaged by repeated cleanings. In a
similar manner,
samples 3 and 9 also gave poor results.
Samples 5 and 11 gave adequate results. Although the topcoat had good
repellency
1o against most types of graffiti, it was only adequate against magic markers.
The results demonstrate that the adhesive composition of the present invention
is
repellent against graffiti by preventing graffiti, including posters, from
adhering to it. The
preferred method for protecting a vandalized substrate is by applying at least
one layer of
primer-sealer, two layers of topcoat and two layers of clear coat.
Alternatively, a cement
is paste may be used to protect the substrate.
While the foregoing embodiment of the invention have been described and shown,
it
is understood that all alternatives and modifications may be made thereto and
fall within the
scope of the invention.
,z
