Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02836978 2013-12-18
SEALANT COMPOSITION
FIELD OF THE INVENTION
The present application relates to a sealant composition.
BACKGROUND OF THE INVENTION
A tire of a vehicle may be punctured by a hard object on the road, and the
punctured tire may roll unsteadily. This situation may cause a traffic
accident and
do physical harm to the driver of the vehicle. In order to avoid this
situation, a
kind of liquid sealant is developed. As a temporary emergent method, the
liquid
sealant can be used for repairing the punctured tire, so that the vehicle can
continue
to travel until reaching a repairing station.
At present, the liquid sealant on the market can be made according to various
formulations. Most current formulations of the liquid sealant contain natural
latex. For example, the invention patent US 6344499 B1 discloses a kind of
sealant comprising 55-60wt% deproteinized natural latex. Another invention
patent US 6992119 B2 discloses a kind of sealant comprising 30-60wt% natural
latex. For the sealing purpose, various kinds of tackifier such as aromatic
terpene
resin or phenol resin can be added to the sealant, as pointed out by the
invention
patent US 6864305 B2. Additionally, the invention patent US 8148448 B2
discloses that 20-40wt% VEVA copolymer resin can be used as the tackifier. The
invention patent US 20120277364 Al discloses that other materials, such as
synthetic latex, can also be used as the tackifier.
As the liquid sealant may be applied at a wide temperature range, most kinds
of the liquid sealant comprises anti-freezing agent. The
choice of the
anti-freezing agent is critical for determining whether the liquid sealant has
a lower
viscosity or not. In the invention patent US 6344499 B1 and the invention
patent
US 6864305 B2, ethylene glycol or propylene glycol can be used as the
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=
anti-freezing agent. However, since ethylene glycol is toxic to the
environment,
ethylene glycol is not preferable. The patent US 7388041 B2 and the patent US
8183309 B2 disclose glycerin, 1, 3-propanediol, and other anti-freezing agents
respectively. To further reducing the viscosity, the patent US 7388041 B2
discloses that potassium acetate can be added into glycerin so that using less
quantity of glycerin can achieve the same anti-freezing effect as using a
large
quantity of pure glycerin.
Furthermore, to improve the sealing performance, solid components can also
be added into the liquid sealant. For example, in the sealant formulation
disclosed by the patent US 7868061 B2, 2.5-10wt% fiber material is added into
the
sealant, and the latex component is reduced to 1-10wt%. In another invention
patent US 7589135 B2, a kind of sealant comprising synthetic short fibers and
rubber latex is disclosed.
Except the sealing performance, the stability of the liquid sealant is also
important, particularly in the liquid sealant comprising natural latex.
Surfactant
can be added into the liquid sealant to improve the stability of the liquid
sealant.
In general, anionic surfactant added into the liquid sealant can achieve a
superior
stabilizing effect, but it would result in a high viscosity of the liquid
sealant,
especially at a low temperature. Thus, the patent US 8242196 B2 mentions that
it
is preferred to use nonionic surfactant. The invention patent US 8470909 132
discloses a combination comprising both anionic surfactant and nonionic
surfactant,
which is configured for improving the stabilization of the liquid sealant.
Although a number of sealant products have been developed, most of them
contain solid contents with large mass percentages (above 15wt%). When these
sealant products are used, they may cause environmental pollution problems or
cleanliness problems. However, other sealant products may be unstable or have
not a good tire sealing effect at a wide temperature range. Furthermore, the
use of
sealant comprising toxic components such as ethylene glycol is undesirable,
and
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solid particles and fibers used in sealant may cause sedimentation problems.
SUMMARY OF THE INVENTION
The objective of the present application is to provide a sealant composition,
aiming at the defect that the sealing performance and the stability of the
sealant in
the prior art are not good.
The technical solutions of the present application for solving the technical
problems are as follows:
In one aspect, a sealant composition is provided, the sealant composition
comprises latex emulsion, nanoporous particles, surfactant, anti-freezing
agent,
wetting agent, and water.
In one embodiment, the nanoporous particles include at least one of zeolite,
silica aerogel, mesoporous silica, carbon aerogel, mesoporous carbon,
activated
carbon, cenosphere, diatomite, porous metal organic frameworks (M0Fs).
In another embodiment, the weight percentage of the nanoporous particles in
the sealant composition is ranged from 0.01% to 5%.
In another embodiment, the weight percentage of the anti-freezing agent in
the sealant composition is ranged from 40% to 90%.
In another embodiment, the anti-freezing agent includes at least one of
propylene glycol, glycerin, diethylene glycol, and 1,3-propanediol.
In another embodiment, the weight percentage of the latex emulsion in the
sealant composition is ranged from 2% to 20%.
In another embodiment, the weight percentage of the surfactant in the sealant
composition is ranged from 0.1% to 2.5%.
In another embodiment, the weight percentage of the wetting agent in the
sealant composition is ranged from the 0.01% to 5%.
In another embodiment, the sealant composition further comprises
anti-freezing additive, and the anti-freezing additive includes inorganic
salts and/or
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organic salts.
In another embodiment, the sealant composition further comprises assisted
additive, and the assisted additive includes at least one of anti-corrosion
additive,
insecticide, pH-modifier, anti-foaming agent, preservative, colorant, and
odorant.
Various embodiments relate to a sealant composition, comprising: an adhesive
agent consisting of latex emulsion, at least one nanoporous particle
consisting
essentially of zeolite, carbon aerogel, mesoporous carbon, activated carbon,
cenosphere, porous metal, and organic chelating compounds, surfactant,
anti-freezing agent, wetting agent, pH-modifier, and water, wherein the
anti-freezing agent has a weight percentage in the sealant composition ranging
from 40% to 90%, wherein the weight percentage of the nanoporous particles in
the sealant composition is less than about 5%.
The sealant composition of the present application achieves a good sealing
performance for the puncture of the tire. Furthermore, the sealant composition
is
easy to use and non-perishable, and has a long shelf life, which endows the
sealant
composition with a good market prospect.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present application discloses a sealant composition for repairing tires.
The sealant composition comprises latex emulsion, and solid particles and
fibers
configured for achieving the sealing purpose. When the sealant composition
flows through a tire puncture, a pressure difference between the interior of
the tire
and the external environment generates great shearing force, and the shearing
force
makes the latex emulsion form solid rubber. In this way, the tire puncture is
sealed.
Specifically, in the present application, the sealant composition comprises
the
latex emulsion, nanoporous particles, surfactant, anti-freezing agent, wetting
agent,
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and water. Furthermore, the sealant composition further comprises anti-
freezing
additive.
Furthermore, in the present application, the latex emulsion can be natural
latex or synthetic latex. If the latex emulsion is natural latex, the natural
latex
including no impurity such as unwanted proteins, lipid, minerals, inorganic
ions,
and other contaminants is preferable, and should be capable of being obtained
by
means of purchase. The quality of the natural latex depends on the source of
the
latex material. The latex emulsion can also be synthetic latex such as NBR or
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SBR. In the present application, the weight percentage of the latex emulsion
in
the sealant composition is ranged from 2% to 20%, preferably from 6% to 11%.
Furthermore, in the present application, the nanoporous particles can be
granular, fibrous, or in other shapes. The nanoporous particles have a low
density
because of the nanoporous structures, so the sedimentation odds of the sealant
composition including the nanoporous particles are decreased. Moreover, a
small
amount (by weight) of the nanoporous particles can enhance the sealing
performance for tire punctures of the sealant composition effectively because
of its
low density, so that the sealant composition including the nanoporous
particles has
a wider market prospect than normal sealant compositions.
Specially, in the present application, a small amount of nanoporous particles
involved in the sealant composition may deposit or settle, but deposited or
settled
nanoporous particles can be easily dispersed again by slightly shaking the
sealant
compositon. The nanoporous particles can include at least one of zeolite,
silica
aerogel, mesoporous silica, carbon aerogel, mesoporous carbon, activated
carbon,
cenosphere, diatomite, and porous metal and organic chelating compounds (e.g.,
metal organic frameworks). Furthermore, in the present application, the
nanoporous particles with chitosan gel particles can also be added into the
sealant
composition, and the method for adding the chitosan gel particles into the
sealant
composition has been disclosed by the previous invention patent US 20120118199
Al.
In the present application, the pore size of the nanoporous particles is at
least
0.5nm, preferably larger than 2nm, and the porosity of the nanoporous
particles is
ranged from 0.1 to 0.95. Moreover, the nanoporous particles can be granular,
fibrous, or in other shapes, and the particle size of the nanoporous particles
is less
than 100 microns. Furthermore, when the specific surface area of the
nanoporous
particles is measured by the nitrogen absorption method, the specific surface
area
of the nanoporous particles should be more than 100 m2/g. The weight
CA 02836978 2013-12-18
percentage of the nanoporous particles in the sealant composition is ranged
from
0.01% to 5%, and preferably from 0.1% to 1%.
Furthermore, in the present application, the sealant composition further
comprises the water used as the medium configured for enabling the latex
emulsion and the nanoporous particles to suspend. In the present application,
the
weight percentage of the water in the sealant composition is ranged from 0.01%
to
42%.
In the present application, the sealant composition further comprises at least
one kind of anti-freezing agent, such as glycol. The anti-freezing agent is
used to
widen an operational temperature range of the sealant composition. The
anti-freezing agent can be at least one of propylene glycol, glycerin,
diethylene
glycol, and 1, 3-propanediol, etc. In the present application, the weight
percentage of the anti-freezing agent in the sealant composition is ranged
from
40% to 90%. Besides, when the sealant composition includes two or more kinds
of anti-freezing agent, there is no limitation to the ratio between different
kinds of
anti-freezing agent.
Furthermore, the sealant composition can further comprise the anti-freezing
additive, and the weight percentage of the anti-freezing additive in the
sealant
composition is ranged from 0.01% to 10%. The anti-freezing additive includes
inorganic salts and/or organic salts (e.g., potassium acetate) used to enhance
the
anti-freezing effect of the sealant composition. In the present application,
the
operational temperature range of the sealant composition is between -40 C and
80 C .
Furthermore, the sealant composition further comprises at least one kind of
surfactant. The surfactant is used to improve the stability of the latex
emulsion so
as to extend the shelf life of the sealant composition. The surfactant can be
added
into the sealant composition directly, and can also be mixed with the latex
emulsion and then added into the sealant composition.
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The surfactant can be anionic surfactant and/or non-ionic surfactant. The
non-ionic surfactant can be at least one of polyoxyalkylene alkyl ether,
polyoxyalkylene alkenyl ether, polyoxyethylene alkylamine, and triethanolamine
laurate. The anionic surfactant can be SDS. Although SDS may increase the
viscosity of the sealant composition, it can stabilize the latex emulsion in
the
sealant composition effectively.
The sealant composition can include composite surfactant formed by mixing
different kinds of surfactant together, wherein the kinds of the surfactant
for
forming the composite surfactant can be selected according to the kind and the
amount of the latex emulsion used in the sealant composition. The composite
surfactant can be a mixture of different kinds of nonionic surfactant, a
mixture of at
least one kind of nonionic surfactant and at least one kind of anionic
surfactant, or
a mixture of different kinds of anionic surfactant.
In the present application, the weight percentage of the surfactant in the
sealant composition is ranged from 0.1% to 2.5%.
Furthermore, the sealant composition further comprises the wetting agent
(e.g.,
alcohol, ether, or ester) used to improve the wettability, viscosity, and
spreading
property of the sealant composition. The wetting agent is used to decrease the
surface tension of the sealant composition, so that the sealant composition
can
spread to an end surface area of a tire more easily. Thus, the sealant
composition
can effectively seal a puncture out of a tread area of a tire.
In the present application, the wetting agent can be ethanol, propanol,
isopropanol, ethyl butyrate, dimethyl succinate, or other chemical materials,
etc.
These wetting agents have low surface tension, so that the surface tension of
the
sealant composition can be effectively reduced when these wetting agents are
added into the sealant composition. In the present application, the weight
percentage of the wetting agent in the sealant composition is ranged from the
0.01% to 5%. It is evident that the wetting agent decreases the contact angle
of
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the sealant composition. Meanwhile, the wetting agent can enhance the
anti-freezing effect and stabilizing effect of the sealant composition.
Additionally, the sealant composition can further comprise assisted additive.
The assisted additive includes at least one of anti-corrosion additive,
insecticide,
pH-modifier, anti-foaming agent, preservative, colorant, and odorant.
The assisted additive is used to add corresponding functions of the sealant
composition. For example, the preservative can be added into the sealant
composition for preserving the bio-degradable components in the sealant
composition, so that the shelf-life of the sealant composition can be extended
to
five years or more. The anti-corrosion additive can be added into the sealant
composition to prevent the interior of a tire from rusting. The colorant can
be
used to dye the sealant composition, and the odorant can be used to eliminate
pungent smell of the sealant composition. The colorant and the odorant do not
cause any adverse effect on the sealing property of the sealant composition.
The
anti-foaming agent can be optionally added into the sealant composition to
prevent
the sealant composition from foaming. The pH-modifier is used for adjusting
the
pH of the sealant composition. When the pH of the sealant composition is more
than 8, the latex emulsion in the sealant composition is more stable. The
weight
percentage of the assisted additive in the sealant composition is arranged
from
0.01% to 1%.
The sealant composition of the present application can perform a significant
sealing effect on a puncture of a tire caused by a spike with the length that
is less
than 8 mm. The sealant composition can keep the puncture of the tire being
sealed for about 12-48 hours.
In the present application, the viscosity of the sealant composition is in the
range of 18-800mPas, and can change with the ambient temperature. The pH of
the sealant composition is adjusted to be more than 8, preferably in the range
of
8-11. When the pH of the sealant composition is between 8 and 11, the latex
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emulsion in the sealant composition is more stable. Furthermore, when the
nanoporous particles are used to replace solid particles with a high density
used in
typical sealant compositions, the sealant composition does not generate
evident
settlement in at least 24 hours. When the surfactant and the preservative are
added into the sealant composition, the sealant composition can maintain the
proper function thereof for more than five years. In use, the sealant
composition
is injected into a tire through a hose under the action of compressed air,
wherein,
the injection pressure is preferably 2.5-10bar, and the valve core of the tire
can be
either removed or not. In addition, the sealant composition can spread to
reach
the end surface area of the tire, so that a puncture out of the tread area of
the tire
can also be effectively sealed.
To test the sealant performance of the sealant composition on tires, a spike
with a length that is less than 8mm is used to form a puncture formed on a
tire.
The tire is mounted onto a vehicle, and the sealant composition is injected
into the
tire. The vehicle with the tire is then driven to run for less than 20km.
Every
time when the vehicle runs for 2-5km, the air leakage of the tire is checked
by
measuring the inner tire pressure. In this way, the sealing effect on the tire
puncture, which is caused by the sealant composition, can be recorded by the
aforementioned method. If the decrement of the inner tire pressure is less
than
0.2bar, it is indicated that the sealant composition seals the tire puncture
successfully, that is, the sealing performance of the sealant composition is
good.
After the tire is detached from the vehicle, the tire is kept being
stationary, with the
tire puncture facing upwards. The pressure decrement can be measured again
after 24h or 48h to confirm the sealing performance.
The shelf life of the sealant composition can be tested by static aging test
and
heat dynamic test. In the static aging test, the sealant composition is placed
in an
oven at a temperature of 70 C or more for more than 40 days, and thus the
sealing
performance of the sealant composition can be tested as described above.
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Twelve embodiments of the sealant composition are shown as follows.
Embodiment 1
The sealant composition comprises: 17.39wt% water, 55vvt% glycerin, 20wt%
natural latex, 5wt% ethanol, lwt% non-ionic surfactant, 1.5wt% anionic
surfactant,
0.01wt% silica aerogel, and 0.1wt% assisted additive.
Embodiment 2
The sealant composition comprises: 32.0 lwt% water, 40wt% glycerin, 5wt%
potassium acetate, 5wt% Inorganic salt, lOwt% natural latex, 2.5wt% ethanol,
lwt% non-ionic surfactant, 0.5wt% anionic surfactant, lwt% mesoporous silica,
0.5wt% silica aerogel, 1.99wt% activated carbon, and 0.5wt% assisted additive.
Embodiment 3
The sealant composition comprises: 33.15wt% water, 50wt% glycerin, 14wt%
synthetic latex, 2.2wt% ethanol, 0.35wt% non-ionic surfactant, 0.2wt%
cenosphere,
and 0. lwt% assisted additive.
Embodiment 4
The sealant composition comprises: 38.3wt% water, 48wt% glycerin, lOwt%
synthetic latex, 2.5wt% ethanol, 0.7wt% non-ionic surfactant, 0.2wt% anionic
surfactant, 0.2wt% silica aerogel, and 0.1wt% assisted additive.
Embodiment 5
The sealant composition comprises: 38.2wt% water, 48wt% 1,3-propanediol,
lOwt% synthetic latex, 2.5wt% ethanol, 0.7vvt% non-ionic surfactant, 0.3wt%
anionic surfactant, 0.2wt% mesoporous carbon, and 0.1wt% assisted additive.
Embodiment 6
The sealant composition comprises: 38.35wt% water, 48wt% propylene
glycol, lOwt% synthetic latex, 2.5wt% isopropanol, 0.7wt% non-ionic
surfactant,
0.3wt% anionic surfactant, 0.05wt% silica aerogel, and 0.1wt% assisted
additive.
Embodiment 7
The sealant composition comprises: 14.7wt% water, 70wt% glycerin, 5wt%
CA 02836978 2013-12-18
inorganic salt, 5wt% natural latex, 2wt% non-ionic surfactant, 2wt% silica
aerogel,
1wt'Yo zeolite, and 0.3wt% assisted additive.
Embodiment 8
The sealant composition comprises: 2.8wt% water, 90wt% propylene glycol,
2wt% synthetic latex, 0.1wt% anionic surfactant, 2wt% silica aerogel, 3wt%
carbon aerogel, and 0.1wt% assisted additive.
Embodiment 9
The sealant composition comprises: 40.3wt% water, 45wt% propylene glycol,
2wt% potassium acetate, 8wt% synthetic latex, 2.5wt% isopropanol, lwt%
non-ionic surfactant, 0.6wt% anionic surfactant, 0.2wt% mesoporous silica,
0.1wt% silica aerogel, 0.1wt% carbon aerogel, 0.1wt% cenosphere, and 0.1wt%
assisted additive.
Embodiment 10
The sealant composition comprises 34.3wt% water, 48wtcY0 propylene glycol,
2wt% potassium acetate, lOwt% synthetic latex, lwt% isopropanol, 2wt%
n-propanol, 0.7wt% non-ionic surfactant, 0.5wV/0 anionic surfactant, 0.2wt%
mesoporous silica, 0.2wt% activated carbon, 0.1wt% cenosphere, and lwt%
assisted additive.
Embodiment 11
The sealant composition comprises: 28.6wt% water, 54wt% glycerin, lOwt%
synthetic latex, 5w0/0 ether, lvvt% non-ionic surfactant, 0.1wt% anionic
surfactant, 0.2wt% activated carbon, 0. lwt% cenosphere, and lwt% assisted
additive.
Embodiment 12
The sealant composition comprises: 28.6wt% water, 54wt% glycerin, lOwt%
synthetic latex, 5wt% ester, lwt% non-ionic surfactant, 0.1wt% anionic
surfactant,
0.2wt% activated carbon, 0.1wt% cenosphere, and lwt% assisted additive.
Table 1 shows test results of the above-mentioned twelve embodiments of the
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present application as follows.
Table 1
Viscosity Viscosity Solid Sealing Cream
Embodiment Aging
(mPas) (mPas) pH content perfor- formation
number tests
at -30 C at 25 C (%) mance (wt%)
1 239 35 11 12.3 Good Pass <10
2 310 28 11.5 10 Good Pass <10
3 165 32 10.5 9.3 Good Pass <10
4 160 36 10.5 7.2 Good Pass <10
130 18 10.8 7.3 Good Pass <10
6 202 25 11 7.1 Good Pass <10
7 720 25 10.9 8 Good Pass <10
8 800 48 9 6.3 Fair Pass <10
9 220 26 8 6.6 Good Pass <10
220 20 9.5 7.7 Good Pass <10
11 250 20 10 7.4 Good Pass <10
12 261 26 10 7.4 Good Pass <10
In the present application, the viscosity of the sealant composition is ranged
from 18mPas to 800mPas; and the pH of the sealant composition is ranged from 8
to 11. The operational temperature of the sealant composition is ranged from
-40 C to 80 C. The sealant composition can seal the puncture of the tire for
more
than 24 hours. After the sealant composition is used to seal the tire
puncture, it
can be cleaned easily by water flushing.
Above all, the sealant composition of the present application achieves a good
sealing performance for the puncture of the tire. Furthermore, the sealant
composition is easy to use and non-perishable, and has a long shelf life,
which
endows the sealant composition with a good market prospect.
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While the embodiments of the present application are described with
reference to the accompanying drawings above, the present application is not
limited to the above-mentioned specific implementations. In fact,
the
above-mentioned specific implementations are intended to be exemplary not to
be
limiting. In the inspiration of the present application, those ordinary skills
in the
art can also make many modifications without breaking away from the subject of
the present application and the protection scope of the claims. All these
modifications belong to the protection of the present application.
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