Note: Descriptions are shown in the official language in which they were submitted.
CA 02236499 1998-OS-O1
WATER-PERMEABLE, FROST-RESISTANT
RESURFACING COMPOSITION
The present invention pertains to improvements
in the field of resurfacing deteriorated surfaces. More
particularly, the invention relates to a water-permeable,
frost-resistant resurfacing compositions.
Chipped, cracked, spalled or stained concrete,
asphalt, brick, flagstone, tile and wood present problems.
Not only are they unappealing to the eye, but also cause
structural damages if they are left unrepaired. When they
are coated with a water-impermeable resurfacing
composition, for example a bituminous composition, water
remains on the surface and renders it slippery, which may
represent a hazard, particularly during winter.
U.S. Patent No. 5,432,213 has proposed a water-
permeable resinous composition for road paving, comprising
100 parts by weight of granular aggregate such as crushed
stone, 2 to 20 parts by weight of a thermosetting resin as
a binder, and 1 to 20 parts by weight of cellulose or 1 to
parts by weight of lignocellulose as an additive per
100 parts by weight of the thermosetting resin. Although
25 water penetrates through such a paving composition leaving
a non-slip surface, the water trapped inside the
composition upon freezing during winter expands and causes
the binder to break, resulting in the formation of cracks
in the surface.
It is therefore an object of the present
invention to overcome the above drawbacks and to provide a
water-permeable, frost-resistant resurfacing composition.
According to one aspect of the invention, there
is provided a water-permeable, frost-resistant
resurfacing composition, comprising from 88 to 93 wt.~ of
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granules of relatively hard material having a particle
size of -12 to +40 mesh and from 7 to 12 wt.~ of an
elastomeric binder, the granules being bonded together
while defining therebetween voids for receiving water.
Expansion of the water contained in the voids upon
freezing is compensated by a corresponding expansion of
the binder, without rupture.
The present invention also provides, in another
aspect thereof, a substrate having a surface at least
partially coated with a water-permeable, frost-resistant
composition as defined above. Such a coated substrate can
be in the form of a prefabricated tile or panel.
Applicant has found quite unexpectedly that a
water-permeable, frost-resistant resurfacing composition
can be obtained by mixing 88 to 93 wt.~ of granules of
relatively hard material having a particle size of -12 to
+40 mesh with 7 to 12 wt.~ of an elastomeric binder. If
the amount of binder is less than 7 wt. o, the granules
are insufficiently bonded together, causing the formation
of cracks in the surface during winter. On the other
hand, if the amount of binder is greater than 12 wt.~,
the voids defined between the granules become filled with
binder, thereby rendering the composition water-
impermeable. The particle size of the granules is also
critical since, if it is below +40 mesh, the porosity of
the composition is insufficient to allow the penetration
of water. On the other hand, if the particle size is
above -12 mesh, the voids defined between the granules
become too large so that the expansion of water contained
therein upon freezing cannot be compensated by a
corresponding expansion of the binder, resulting in the
formation of cracks in the surface during winter.
According to a preferred embodiment, the
elastomeric binder is a polyurethane. Preferably, the
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polyurethane binder comprises a moisture-curable
prepolymer obtained from a polyol and a diisocyanate, the
prepolymer being in admixture with a predetermined amount
of the diisocyanate in free form. For example, use can be
made of polypropylene glycol and 4,4'-diphenylmethane
diisocyanate. A particularly preferred prepolymer has the
general formula:
O=C=N ~ ~ CH_~NH-o-O~CH~CHi-O~-'~- NH . ~ ~ CHI ~ ~ N=C=C
~LJ 0
(I)
in which n ranges from 30 to 70. The curing time of such
prepolymer when combined with 25 to 40 wt.%, preferably
about 35 wt.%, of the diisocyanate in free form and
exposure to atmospheric moisture is about 60 minutes. The
polyurethane binder obtained from the prepolymer of
formula (I) has an elongation at break between 300 and
400 %.
Use can also be made of a two-component
polyurethane binder comprising a first component and a
second component. The first component comprises a
prepolymer obtained from a first polyol and a
diisocyanate, the prepolymer being in admixture with a
predetermined amount of the diisocyanate in free form,
and the second component comprises a second polyol in
admixture with a moisture absorbing material. Preferably,
the first polyol is a polypropylene glycol having a
weight average molecular weight of 45 to 135, the second
polyol is a polypropylene glycol having a weight average
molecular weight of 500 to 1000 and the diisocyanate is
4,4'-diphenylmethane diisocyanate, the diisocyanate in
free form being present in the first component in an
amount of 55 to 80 wt.%, preferably 70 wt.%, based on the
total weight of the first component. The first and second
components are generally present in a weight ratio of
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CA 02236499 1998-OS-O1
1:1.22. The polyurethane binder obtained by mixing
together the first and second components has an
elongation at break between 300 and 350.
According to another preferred embodiment, the
relatively hard material comprises crushed stone. For
example, use can be made of a cornian or ceramic type
rock. When using stones of contrasting colors, sizes and
textures, distinctive patterns, designs, monograms and
logos can be created.
A particularly preferred resurfacing
composition according to the invention comprises about
90 wt.$ of the aforesaid granules of relatively hard
material and about 10 wt.~ of the elastomeric binder.
The resurfacing composition of the invention
can be applied not only onto horizontal surfaces such as
asphalt driveways and concrete or wood decks, but also
onto vertical surfaces such as retaining walls, columns
and stair risers.
When it is desired to resurface asphalt, a
primer is preferably applied onto the asphalt surface
prior to applying the resurfacing composition of the
invention, in order to increase the adherence of the
resurfacing composition to the asphalt surface. For
example, use can be made of a primer sold by Monsey Bakor
Inc., under Product No. 900-34, which is a water-based
elastomeric bituminous emulsion.
When resurfacing concrete or wood, a water-
impermeable membrane is preferably first applied. Use can
be made, for example, of the membrane sold under the
trade-mark COLPHENE 1500 by Soprema Inc., which is a
self-adhesive membrane composed of bitumen modified with
thermoplastic polymers. The upper side of such a membrane
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CA 02236499 1998-OS-O1
is protected by a cross-laminated high density
polyethylene film. The adhesive side is protected by a
silicone release sheet which is easily removed during
application. In the case of concrete, use can also be
made of the membrane sold under the trade-mark
ELASTOPHENE SP 2.2, sold by Soprema Inc., which is a
torch-applied membrane composed of a glass fleece
reinforcement, SBS (styrene-butadiene-styrene) modified
bitumen and a thermofusible plastic film. The concrete or
wood surface is generally coated with a primer to
increase the adherence of the membrane to the surface.
When using a COLPHENE 1500 membrane, the surface can be
coated with the primer sold under the trademark ELASTOCOL
600 by Soprema Inc., for outdoor applications at ambient
temperature above +10°C, or with the primer sold under
the trade-mark ELASTOCOL 700 by Soprema Inc., for outdoor
applications at lower temperatures, to -10°C. ELASTOCOL
500 is a blend of elastomeric bitumen, volatile solvents,
adhesive enhancing additives and resins. ELASTOCOL 700,
on the other hand, is a blend of synthetic rubber,
volatile solvents and adhesive enhancing additives. For
indoor applications, the concrete or wood surface can be
coated with the primer sold under the trade-mark
ELASTOCOL 350 by Soprema Inc., which is a water-based
stabilized bituminous emulsion. When using an ELASTOPHENE
SP 2.2 membrane, the concrete surface can be coated with
the primer sold under the trade-mark ELASTOCOL 500 by
Soprema Inc., for outdoor applications, or with the
aforementioned ELASTOCOL 350 for indoor applications.
ELASTOCOL 500 is a blend of elastomeric bitumen, volatile
solvents and adhesive enhancing additives.
Further features and advantages of the
invention will become more readily apparent from the
following description of preferred embodiments as
illustrated by way of example in the accompanying
drawings, in which:
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Fig. 1 is a fragmented top plan view
illustrating an asphalt surface partially coated with a
resurfacing composition according to a preferred
embodiment of the invention;
Fig. 2 is a top plan view of a prefabricated
tile according to another preferred embodiment of the
invention; and
Fig. 3 is a sectional view taken along line 3-3
of Fig. 2.
Fig. 1 illustrates an asphalt surface 10
partially coated with a layer 12 of a water-permeable,
frost-resistant resurfacing composition comprising
granules of crushed stone having a particle size of -12
to +40 mesh, in admixture with an elastomeric binder. The
thickness of the layer 12 is generally about 5 mm, but
can vary up to about 15 mm.
The prefabricated tile illustrated in Figs. 2
and 3, and generally designated by reference numeral 14,
comprises a layer 16 of a water-permeable, frost-
resistant composition similar to the resurfacing
composition shown in Fig. l, which has been molded on top
of a self-adhesive membrane 18 of the type sold under the
trade-mark COLPHENE 1500 by Soprema Inc. The adhesive
side of the membrane 18 is covered with a silicone
release sheet 20 which is removed during application. The
thickness of the layer 16 is generally about 5 mm, but
can vary up to about 15 mm.
The following non-limiting examples further
illustrate the invention.
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CA 02236499 1998-OS-O1
Tn'Y11MDT.Ti 1
527.7 grams (93 wt. o) of granules of crushed
pigmented stone having a particle size of -12 to +40 mesh
were mixed in a concrete mixer with 39.7 grams (7 wt.~)
of a polyurethane binder sold under .the trade-mark
ELASTOPUR P-237 by Premilec Inc., which comprises 65 wt.~
of a prepolymer of formula (I) defined herein and 35 wt.o
of 4,4'-diphenylmethane diisocyanate in free form. Mixing
was carried out for a period of about 5 minutes, until
the granules were uniformly coated with the binder. The
composition was poured on a substrate having an area of
0.093 m2 and was spread over the surface with a trowel to
provide a uniform layer having a thickness of 3 mm.
Uniformity was obtained by heating the trowel at a
maximum temperature of 70°C, solvent being sprayed onto
the trowel to provide a uniform finish. A limited period
of 60 minutes is permitted before curing begins.
EXAMPLE 2
1.047 kilograms (92 wt.~) of granules of
crushed pigmented stone having a particle size of -12 to
+40 mesh were mixed in a concrete mixer with 30.8 grams
(8 wt. o) of the polyurethane binder sold under the trade-
mark ELASTOPUR P-237. Mixing was carried out for a period
of about 5 minutes, until the granules were uniformly
coated with the binder. The composition was poured on a
substrate having an area of 0.093 m2 and was spread over
the surface with a trowel to provide a uniform layer
having a thickness of 6 mm. Uniformity was obtained by
helating the trowel at a maximum temperature of 70°C,
solvent being sprayed onto the trowel to provide a
uniform finish. A limited period of 60 minutes is
permitted before curing begins.
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CA 02236499 1998-OS-O1
~'Y11MDT~' '~
2.4 kilograms (90 wt.~) of granules of crushed
pigmented stone having a particle size of -12 to +40 mesh
were mixed in a concrete mixer with 227 .grams (10 wt.~)
of the polyurethane binder sold under the trade-mark
ELASTOPUR P-237. Mixing was carried out for a period of
about 5 minutes, until the granules were uniformly coated
with the binder. The composition was poured on a
substrate having an area of 0.093 m2 and was spread over
the surface with a trowel to provide a uniform layer
having a thickness of 12.5 mm. Uniformity was obtained by
heating the trowel at a maximum temperature of 70°C,
solvent being sprayed onto the trowel to provide a
uniform finish. A limited period of 60 minutes is
permitted before curing begins.
L'Y11MDT L' /I
4.0 kilograms (88 wt.~) of granules of crushed
pigmented stone having a particle size of -12 to +40 mesh
were mixed in a concrete mixer with 544.8 grams (12 wt. o)
of the polyurethane binder sold under the trade-mark
ELASTOPUR P-237. Mixing was carried out for a period of
about 5 minutes, until the granules were uniformly coated
with the binder. The composition was poured on a
substrate having an area of 0.093 m2 and was spread over
the surface with a trowel to provide a uniform layer
having a thickness of 25 mm. Uniformity was obtained by
heating the trowel at a maximum temperature of 70°C,
solvent being sprayed onto the trowel to provide a
uniform finish. A limited period of 60 minutes is
permitted before curing begins.
_ g _
CA 02236499 1998-OS-O1
T: YZ1MDT.&' ~,
527.7 grams (93 wt.~) of granules of crushed
pigmented stone having a particle size of -12 to +40 mesh
were mixed in a concrete mixer with 39.7, grams (7 wt.~)
of a two-component polyurethane binder comprising 17.86
grams (45 wt.~) of a first component sold under the
trade-mark ELASTOPUR P-200 by Premilec Inc. and 21.84
grams (55 wt.~) of a second component sold under the
trade-mark ELASTOPUR R-210 by the same company. ELASTOPUR
P-200 comprises 30 wt.$ of a prepolymer obtained from
polypropylene glycol having a weight average molecular
weight of 45 to 135 and 4,4'-diphenylmethane
diisocyanate, and 70 wt.~ of 4,4'-diphenylmethane
diisocyanate in free form. ELASTOPUR R-210 comprises
90 wt.$ of polypropylene glycol having a weight average
molecular weight of 500 to 1000, 5 wt.~ of 3 ~ molecular
sieve (moisture absorbent) and 5 wt.~ of castor oil.
Mixing was carried out for a period of about 5 minutes,
until the granules were uniformly coated with the binder.
The composition was poured on a substrate having an area
of 0.093 m2 and was spread over the surface with a trowel
to provide a uniform layer having a thickness of 3 mm.
Uniformity was obtained by heating the trowel at a
maximum temperature of 70°C, solvent being sprayed onto
the trowel to provide a uniform finish. A limited period
of 30 minutes is permitted before curing begins.
EXAMPLE 6
1.4 kilograms (92 wt.~) of granules of crushed
pigmented stone having a particle size of -12 to +40 mesh
were mixed in a concrete mixer with 90.8 grams (8 wt.~)
of a two-component polyurethane binder comprising 40.86
grams (45 wt. o) of the aforesaid first component sold
under the trade-mark ELASTOPUR P-200 and 49.94 grams
(55 wt. o) of the aforesaid second component sold under
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CA 02236499 1998-OS-O1
the trade-mark ELASTOPUR R-210. Mixing was carried out
for a period of about 5 minutes, until the granules were
uniformly coated with the binder. The composition was
poured on a substrate having an area of 0.093 m2 and was
spread over the surface with a trowel to provide a
uniform layer having a thickness of 3 mm. Uniformity was
obtained by heating the trowel at a maximum temperature
of 70°C, solvent being sprayed onto the trowel to provide
a uniform finish. A limited period of 30 minutes is
permitted before curing begins.
L'VTTdDT L' '7
2.04 kilograms (90 wt.~) of granules of crushed
pigmented stone having a particle size of -12 to +40 mesh
were mixed in a concrete mixer with 227 grams (10 wt.~)
of a two-component polyurethane binder comprising 102.15
grams (45 wt.~) of the aforesaid first component sold
under the trade-mark ELASTOPUR P-200 and 124.85 grams
(55 wt.~) of the aforesaid second component sold under
the trade-mark ELASTOPUR R-210. Mixing was carried out
for a period of about 5 minutes, until the granules were
uniformly coated with the binder. The composition was
poured on a substrate having an area of 0.093 m2 and was
spread over the surface with a trowel to provide a
uniform layer having a thickness of 12.5 mm. Uniformity
was obtained by heating the trowel at a maximum
temperature of 70°C, solvent being sprayed onto the
trowel to provide a uniform finish. A limited period of
30 minutes is permitted before curing begins.
EXAMPLE 8
4.0 kilograms (88 wt.~) of granules of crushed
pigmented stone having a particle size of -12 to +40 mesh
were mixed in a concrete mixer with 544.8 grams (12 wt.$)
of a two-component polyurethane binder comprising 245.16
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CA 02236499 1998-OS-O1
grams (45 wt.%) of the aforesaid first component sold
under the trade-mark ELASTOPUR P-200 and 229.64 grams
(55 wt.%) of the aforesaid second component sold under
the trade-mark ELASTOPUR R-210. Mixing was carried out
for a period of about 5 minutes, until the granules were
uniformly coated with the binder. The composition was
poured on a substrate having an area of 0.093 m2 and was
spread over the surface with a trowel to provide a
uniform layer having a thickness of 25 mm. Uniformity was
obtained by heating the trowel at a maximum temperature
of 70°C, solvent being sprayed onto the trowel to provide
a uniform finish. A limited period of 30 minutes is
permitted before curing begins.
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