U.S. patent application number 14/323660 was filed with the patent office on 2015-01-01 for elastomeric coatings having hydrophobic and/or oleophobic properties.
The applicant listed for this patent is Ross Technology Corporation. Invention is credited to Michael Hurley, Andrew K. Jones, Zenas W. Lim, Andrew McLean, Vinod K. Sikka.
Application Number | 20150005424 14/323660 |
Document ID | / |
Family ID | 49783982 |
Filed Date | 2015-01-01 |
United States Patent
Application |
20150005424 |
Kind Code |
A1 |
Jones; Andrew K. ; et
al. |
January 1, 2015 |
Elastomeric Coatings Having Hydrophobic and/or Oleophobic
Properties
Abstract
This disclosure deals with novel formulations to create highly
durable hydrophobic, superhydrophobic, oleophobic and/or
superoleophobic surfaces that can be nearly transparent. The
formulations of this invention can be applied by dip, spray and
painting processes.
Inventors: |
Jones; Andrew K.;
(Lancaster, PA) ; Lim; Zenas W.; (Lancaster,
PA) ; McLean; Andrew; (Coatesville, PA) ;
Sikka; Vinod K.; (Oak Ridge, TN) ; Hurley;
Michael; (Lancaster, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ross Technology Corporation |
Leola |
PA |
US |
|
|
Family ID: |
49783982 |
Appl. No.: |
14/323660 |
Filed: |
July 3, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14229047 |
Mar 28, 2014 |
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14323660 |
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PCT/US13/31751 |
Mar 14, 2013 |
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14229047 |
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61663985 |
Jun 25, 2012 |
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61708760 |
Oct 2, 2012 |
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61768290 |
Feb 22, 2013 |
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Current U.S.
Class: |
524/263 |
Current CPC
Class: |
B65D 83/752 20130101;
C09D 7/69 20180101; C09D 153/00 20130101; C08K 5/5406 20130101;
C09D 183/04 20130101; Y10T 428/24355 20150115; C08K 7/22 20130101;
C09D 153/02 20130101; C09D 183/16 20130101; C09D 5/1681
20130101 |
Class at
Publication: |
524/263 |
International
Class: |
C09D 153/00 20060101
C09D153/00 |
Claims
1. A system for forming a coating comprising: A) a first component
which comprises: i) an elastomeric binder comprising one or more
styrenic block copolymers, wherein said elastomeric binder
comprises from about 10% to about 30% of said one or more styrenic
block copolymers by weight; ii) optionally, one or more
independently selected first particles having a size of about 30
microns to about 225 microns, wherein, when said first particles
are present, the first component comprises from about 0.01% to
about 5% of said first particles by weight; and iii) one or more
solvents; and B) a second component which either comprises: i) one
or more independently selected second particles having a size of
about 1 nanometer to about 25 microns, wherein said second
particles comprise one or more independently selected alkyl,
haloalkyl, or perfluoroalkyl moieties bound, either directly or
indirectly, to said second particles, and ii) optionally, one or
more solvents; or comprises per 100 parts by weight: i) 0.1 to 3.5
parts by weight of one or more independently selected second
particles having a size of about 1 nanometer to about 25 microns,
wherein said second particles comprise one or more independently
selected alkyl, haloalkyl, or perfluoroalkyl moieties bound, either
directly or indirectly, to said second particles, or one or more
siloxanes or silazanes associated with said second particles; ii)
0.1 to 1.0 parts by weight of a fluorinated polyolefin; and/or 0.06
to 0.6 parts by weight of a Fluoroethylene-Alkyl Vinyl Ether (FEVE)
copolymer, having an average molecular weight of about 1,000 to
3,000; and iii) one or more solvent for the remainder of a total of
100 parts by weight; wherein a coating formed by said system has an
elongation at break greater than about 200% and an arithmetical
mean roughness value from about 3 microns to about 20 microns, or a
ten point mean roughness from about 7 microns to about 100
microns.
2. The system of claim 1, wherein one or more of the styrenic block
copolymers has a rubber phase crosslinked to the polystyrene
phase.
3. The system according to claim 1, wherein one or more of the
styrenic block copolymers has a rubber phase comprising
polybutadiene, polyisoprene, polyolefin or a mixture of any of
those rubber phase components (e.g., linear triblock copolymers of
styrene and ethylene/butylene with a polystyrene content of about
8% to about 36% by weight or mixtures of any two or more, three or
more, or four or more of such triblock copolymers, any one or more
of which may optionally comprise 1% to 3% or 1.4% to 2.0% maleic
anhydride).
4. The system according to claim 2, wherein said rubber component
comprises 60%-80%, of the elastomer by weight, based on the dry
weight of the elastomer present in the first component not
including any contribution by the first particles or other
materials present in the first component.
5. The system according to claim 1, wherein said first component
further comprises one or more colorants, UV stabilizers,
antioxidants, rheological agents, and/or fillers.
6. The system according to claim 1, wherein said first component
further comprises up to 30% by weight of one or more tackifiers,
wherein said one or more styrenic block copolymers and said one or
more tackifiers together comprise up to about 30% by weight of said
first component.
7. (canceled)
8. The system according to claim 1, wherein said elastomeric binder
comprises one, two, three, or more triblock copolymers.
9. The system according to claim 1, wherein said elastomeric binder
comprises one or more styrenic block copolymers of styrene and
ethylene/butylene with a polystyrene content of about 8% to about
36% by weight, or mixtures of any two or more, three or more, or
four or more of such triblock copolymers.
10. The system according to claim 1, wherein one or more of said
styrenic block copolymers present in the elastomeric binder
comprise maleic anhydride or a first and a second maleated triblock
copolymer of styrene and ethylene/butylene wherein: said first
maleated triblock copolymer of styrene and ethylene/butylene has a
polystyrene content from about 8% to about 14%, with 0.4% to 1.6%
substitution of maleic anhydride by weight of the first triblock
copolymer; and said second maleated triblock copolymer of styrene
and ethylene/butylene has a polystyrene content of about 22% to
about 32%, with 1.1% to 2.5% substitution of maleic anhydride by
weight of the second triblock copolymer.
11.-14. (canceled)
15. The system according to claim 1, wherein said first particles
are selected from the group consisting of: glass, ceramic, rubber,
plastic, thermoplastic, wood, cellulose, metal oxides, silicon
dioxide, silicates, tectosilicates, germanium dioxide, plastic
particles, carbide particles, nitride particles, boride particles
(e.g., zirconium or titanium boride), spinel particles, diamond
particles, fly ash particles, fibers and hollow glass spheres,
hollow glass particles or hollow plastic particles (e.g., glass,
polymer, plastic or thermoplastic particles, spheres, or
microspheres), wherein said first particles optionally comprise a
colorant (e.g., colored or pigmented glass particles, plastic
particles, rubber particles, hollow glass or hollow plastic
particles).
16.-19. (canceled)
20. The system according to claim 1, wherein said second particles
comprise a metal oxide, an oxide of a metalloid, a silicate, or a
glass, wherein said second particles have an average size in the
range of from 1 nm to 100 nm or from 2 nm to 200 nm.
21.-24. (canceled)
25. The system according to claim 1, wherein said one or more
hydrophobic or oleophobic moieties result from contacting the
second particles with one or more silanizing agents of formula (I):
R.sub.4-nSi--X.sub.n (I) where n is an integer from 1 to 3; each R
is independently selected from (i) alkyl or cycloalkyl group
optionally substituted with one or more fluorine atoms, (ii)
C.sub.1 to 20 alkyl optionally substituted with one or more
substituents independently selected from fluorine atoms and C.sub.6
to 14 aryl groups, which aryl groups are optionally substituted
with one or more independently selected halo, C.sub.1 to 10 alkyl,
C.sub.1 to 10 haloalkyl, C.sub.1 to 10 alkoxy, or C.sub.1 to 10
haloalkoxy substituents, (iii) C.sub.2 to 8 or C.sub.6 to 20 alkyl
ether optionally substituted with one or more substituents
independently selected from fluorine and C.sub.6 to 14 aryl groups,
which aryl groups are optionally substituted with one or more
independently selected halo, C.sub.1 to 10 alkyl, C.sub.1 to 10
haloalkyl, C.sub.1 to 10 alkoxy, or C.sub.1 to 10 haloalkoxy
substituents, (iv) C.sub.6 to 14 aryl, optionally substituted with
one or more substituents independently selected from halo or
alkoxy, and haloalkoxy substituents, (v) C.sub.4 to 20 alkenyl or
C.sub.4 to 20 alkynyl, optionally substituted with one or more
substituents independently selected from halo, alkoxy, or
haloalkoxy, and (vi) --Z--((CF.sub.2).sub.q(CF.sub.3)).sub.r,
wherein Z is a C.sub.1 to 12 or a C.sub.2 to 8 divalent alkane
radical or a C.sub.2 to 12 divalent alkene or alkyne radical, q is
an integer from 1 to 12, and r is an integer from 1 to 4; each X is
independently selected from --H, --Cl, --I, --Br, --OH, --OR.sup.2,
--NHR.sup.3, or --N(R.sup.3).sub.2 group; each R.sup.2 is an
independently selected C.sub.1 to 4 alkyl or haloalkyl group; and
each R.sup.3 is an independently selected H, C.sub.1 to 4 alkyl, or
haloalkyl group.
26. (canceled)
27. The system according to claim 25, wherein R is
--Z--((CF.sub.2).sub.q(CF.sub.3)).sub.r, wherein Z is a C.sub.1 to
12 divalent alkane radical or a C.sub.2 to 12 divalent alkene or
alkyne radical, q is an integer from 1 to 12, and r is an integer
from 1 to 4.
28. The system according to claim 25, wherein n is 1, 2, or 3.
29.-33. (canceled)
34. The system according to claim 1, wherein said second particles
are treated with a silanizing agent selected from the group
consisting of:
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane;
(tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane;
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane;
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethyl(dimethylamino)silane;
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)tris(dimethylamino)silane;
n-octadecyltrimethoxysilane; n-octyltriethoxysilane;
nonafluorohexyldimethyl(dimethylamino)silane; dimethyl
dichlorosilane; hexamethyldisilazane; octyltrimethoxysilane, and
polydimethylsiloxane.
35. (canceled)
36. The system according to claim 1, wherein said first component
and/or said second component further comprises an independently
selected solvent and/or propellant.
37.-39. (canceled)
40. The system according to claim 1, wherein said elastomeric
binder has an ultimate strength greater than about 20 Mega Pascals
(MPa) according to ASTM D412.
41-62. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/663,985, filed Jun. 25, 2012; U.S. Provisional
Application No. 61/708,760, filed Oct. 2, 2012; and U.S.
Provisional Application No. 61/768,290, filed Feb. 22, 2013, the
entirety of each of which application is incorporated herein by
reference.
BACKGROUND
[0002] The surfaces of objects that are exposed to the environment
come into contact with a variety of agents, including dust,
moisture, water, and oils. In industrial applications, surfaces may
be exposed to a variety of agents in addition to water, such as
aqueous salt solutions, solutions of aqueous acid or base, and
chemical components that may be dissolved or suspended in aqueous
compositions or other liquids, including those used in
manufacturing processes. Not only are the surfaces of objects
exposed to a variety of chemical agents, but the temperatures to
which the surfaces are exposed can also affect their interaction
with those agents and the performance of the coated surfaces of
objects. For example, freezing liquids, such as water, can result
in frozen deposits tightly attached to the surfaces that prevent
access to the surfaces and in some instances prevent proper
operation of equipment bound by the frozen liquid. In addition,
elevated temperatures can accelerate processes such as corrosion or
leaching.
SUMMARY
[0003] Embodiments of coatings and surface treatments are provided
herein that can provide advantageous surface properties including,
but not limited to, hydrophobicity or superhydrophobicity
(collectively HP), oleophobicity or superoleophobicity
(collectively OP), and resistance to ice formation, adherence
and/or accumulation. Embodiments of the coatings described herein
that are HP and OP, and which may also display anti-icing behavior,
may be applied to a surface using two or more steps. Embodiments of
methods of applying such coatings and surface treatments also are
provided, together with embodiments of compositions for applying
such coatings and surface treatments, and surfaces and/or objects
so treated and coated are provided as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a schematic showing an embodiment of a polystyrene
and rubber elastomeric copolymer.
[0005] FIG. 2 is a schematic showing various spatial orientations
of embodiments of polystyrene and rubber copolymers. S is styrene
and B is a rubber phase (i.e. butylene).
[0006] FIG. 3 shows some solvents suitable for dissolving styrene
(styrenic) block copolymers (SBCs). The scale represents suitable
solvents that can be used as SBC copolymers. Letters to the left
axis are indicators of: S (styrene), B butylene (polybutadiene), I
(polyisoprene), and EB (ethylene/butylene). Those solvents
indicated as "Good Solvents" are solvents that tend to dissolve or
suspend SBC polymers.
[0007] FIG. 4 depicts a shower test apparatus. The upper panel
shows the showerhead with 70 nozzles with a 1 mm diameter orifice
arranged in 5 spokes of 5 nozzles and 15 spokes of 3 nozzles about
a central point on a circular showerhead. For testing the
showerhead delivers approximately 6 liters of potable tap water per
minute using about 137900 Pa (Pascals) to 310275 Pa. The lower
panel depicts a sample, which is placed about 1.5 meters below the
showerhead and subject to the shower.
[0008] FIG. 5 shows a plot of "glove rubs," which are an estimate
of the surface resistance to the loss of either or both of HP or OP
properties as a function of percentage of EXPANCEL first particles
employed in a nearly transparent coating prepared without
colorants. The glove rub estimates tend to trend in the same
direction as loss of HP or OP properties due to handling, abrasion
resistance, and/or the shower time. The weight percent of EXPANCEL
particles is given as the percentage of the base coat formulation
weight as opposed to a dry weight basis (see Example 1).
[0009] FIG. 6 shows the variation in the resistance to the loss of
superhydrophobic behavior of an elastomeric binder system due to
wear based on "glove rubs" and exposure to a shower of water using
five different types of EXPANCEL particles. Duplicate samples
containing EXPANCEL 031 DU 400 heated before or after the second
component (referred to as "top coat") comprising hydrophobic fumed
silica in acetone is applied. See Example 2 for details.
[0010] FIG. 7 shows the effect of coating thickness on coating
resistance to the loss of superhydrophobic behavior due to wear
based on Taber Abraser testing using a 1,000 g load and CS-10
wheels on 10.times.10 cm plates treated with 2 or 4 ml of top coat
(second component) applied over the base coating. See Example 5 for
details.
[0011] FIG. 8 shows Thermogravimetric Analysis (TGA) data for a
nearly transparent elastomeric coating incorporating EXPANCEL461
EXPANCEL DE 40 D 25 microspheres.
[0012] FIG. 9 shows TGA data for an embodiment of a non-transparent
HP/OP elastomeric coating incorporating SoftSand.TM. rubber
particles.
DETAILED DESCRIPTION
[0013] Embodiments of elastomeric coating methods, compositions,
and treatments are provided that impart a variety of desirable
characteristics to objects and their surfaces, including
hydrophobicity (including superhydrophobicity), oleophobicity
(including superoleophobicity), and/or anti-icing. As used herein,
the term "hydrophobicity" and the abbreviation HP includes
superhydrophobicity, and the term "oleophobicity" and the
abbreviation OP includes superoleophobicity. The abbreviation
"HP/OP" is used collectively herein to mean HP and/or OP and may
also include anti-icing properties (including ice formation,
adherence and/or accumulation). Treating surfaces with coatings
having HP/OP characteristics can result in objects and surfaces
with a variety of advantageous properties including, but not
limited to, resistance to wetting, corrosion, swelling, rotting,
cracking or warping, exfoliation, fouling, dust and/or dirt
accumulation on surfaces (self cleaning), and resistance to surface
ice formation, adherence and/or accumulation. Not only do
embodiments of the coating compositions and treatments described
herein provide properties including HP/OP, but the coatings also
are durable in that they substantially retain those properties
despite some amount of mechanical abrasion. In addition to
providing durable HP/OP behavior, embodiments of the elastomeric
coatings can also remain flexible and provide substantial
resistance to cracking, peeling, and delamination from the coated
surface over a wide range of temperatures. Further, embodiments of
the coatings can readily be repaired where the surface has been
abraded sufficiently to compromise the coating's properties
including HP/OP behavior.
[0014] Embodiments of the HP/OP elastomeric coatings described
herein may be applied in a process comprising two or more steps in
which the first component applied comprises an elastomeric binding
agent and optionally comprises first particles. Once applied, the
coating formed by the first component is termed a "substrate
coating," a "base coating," or a "base coat" particularly when
dried. Following the application of the elastomer base coat, an
amount of second component is applied to the base coat. The second
component comprises second particles that are treated to cause the
second particles, and the coatings into which they are suitably
incorporated, to display advantageous properties including HP/OP
and/or anti-icing behavior. The second component may be applied to
an elastomeric base coat after the base coat is applied, but before
it is dried and/or set. Alternatively, depending on the
carrier/solvent used with the second component, the second
component may be applied to the elastomer after the base coat is
dried and/or set.
[0015] The use of second component coating compositions comprising
solvents that can be applied to the elastomeric base coat after it
has dried and set permits repair of coatings that have been abraded
or otherwise damaged to the point where the desired HP/OP
properties is/are no longer observed. Provided the base coat is
intact, or the base coat has not been damaged to the point that
material underlying the base coat is exposed, repair is
accomplished by the reapplication of the second component which
comprises second particles.
[0016] Where the HP/OP elastomeric coatings have been abraded so as
to compromise the elastomer binder coating or its properties (e.g.,
abraded, worn too thin, or damaged to the point where the surface
of the coated object or underlying material such as a primer is
exposed), the coating may be reapplied to the abraded area (i.e.,
it may be repaired) by repeating the application of both the first
and second components. Suitable repair/preparation of
exposed/damaged surfaces and/or underlying primers may be required
prior to the reapplication of the elastomeric coating. In contrast,
other HP or OP coatings using non-elastomeric binder systems (e.g.,
polyurethane systems) may not be as readily repaired because the
HP/OP behavior of the original coating that remains in place can
prevent newly applied coating compositions from binding to the
surface.
[0017] In one embodiment, a method of applying a HP/OP coating to a
substrate comprises the steps of: [0018] a) applying to the
substrate a first component comprising: i) an elastomeric binder
comprising one or more styrenic block copolymers, and optionally
comprising ii) first particles having a size of about 1 micron to
about 300 microns (e.g., 10 microns to about 100 microns), to
provide a base coating; and [0019] b) applying to the base coating
a second component comprising second particles having a size of
about 1 nanometer to 25 microns, where the second particles are
associated with one or more siloxanes and/or have one or more
independently selected alkyl, haloalkyl, or perfluoroalkyl groups
covalently bound, either directly or indirectly, to the second
particles, and wherein the second component optionally comprises an
agent to suspend or assist in suspending the particles (e.g., a
solvent such as hexane or tert-butyl acetate). To assist in the
application process, embodiments of the first and second components
may include any necessary solvents, liquids or propellants.
[0020] In some embodiments of the application method, the base
coating is treated with the second component after drying and
curing the base coating at room temperature (e.g., about 18 to
about 23.degree. C.) or at an elevated temperature (e.g., about
30.degree. to about 100.degree. C., about 30.degree. to about
60.degree. C., about 50.degree. to about 100.degree. C., or about
40.degree. to about 90.degree. C.). In other embodiments, the
solvent used to apply the base coat is allowed to evaporate until
the coating is no longer liquid and cannot be removed by contact
(i.e., dry to the touch); however, the base coating is not fully
dried and cured when treated with the second component containing
second particles. In still other embodiments, the composition
comprising second particles may be applied directly to the base
coat before solvents used in the application of the base coating
have fully, substantially, or partly evaporated.
[0021] Diverse elastomeric binders, first particles, and second
particles may be employed in the methods and compositions described
herein. In some embodiments, first particles may be filler
particles. In some embodiments second particles may be considered
nanoparticles. In some embodiments described herein, the coating
formed by the application of the first and second components will
be nearly transparent to visible light. In other embodiments, the
coatings may be colored but nearly transparent to visible light
that is not absorbed by the coating components and/or colorants. In
still other embodiments, the coatings will have colorants (e.g.,
insoluble pigments or colored first and/or second particles) that
will render them opaque or block the transmission of light.
Embodiments of such coating components, materials, and compositions
are described more fully below.
[0022] A skilled artisan will readily understand that the selection
of first particles and second particles needs to include
consideration of not only the desired properties of the coating and
the ultimate conditions to which the coating will be subject in
use, but also the process used to prepare the coating. Where, for
example, particles must withstand elevated temperatures or specific
solvents in the coating process, they should be selected so as to
be suitable for use in the required temperature ranges or in the
required solvents. For example, in those embodiments where coatings
or the first and/or second particles are intended for use at
elevated temperatures (e.g., above room temperature), the particles
need to be compatible with the elevated temperatures that the
coatings will be subjected to when in use and/or in processes
employed to prepare the coatings. Similarly, the particles should
be selected to be compatible with solvents used in the application
process and with solvents the coatings will become exposed to in
use.
[0023] In methods described herein, where second particles are
applied to a base coat on a substrate, which may be coated with a
primer, the methods can produce coatings having (i) a surface in
contact with said substrate (or primer) and (ii) an exposed surface
that is not in contact with the substrate (or primer) where these
surfaces bear different amounts of first particles, second
particles, or both first and second particles. In some embodiments
the exposed surface can have a greater amount of first and/or
second particles on, at, or adjacent to the exposed surface,
compared to the amount of first and/or second particles at or
adjacent to the surface of the coating that is in contact with the
substrate (or primer). In one embodiment the coatings have a
greater amount of second particles on, at, or adjacent to the
exposed surface than the surface of the coating that is in contact
with the substrate (or primer). In embodiments where a greater
amount of first and/or second particles may be present at the
exposed surface, the coatings may be considered composite
coatings.
[0024] The amount of particles in any portion of a coating may be
assessed by any means known in the art including, but not limited
to, microscopy or electron microscopy. Using those techniques on
cross or oblique sections of coatings, the amount (e.g., the
number) of particles can be determined. In addition, where it is
possible to remove coatings, or where the substrate permits (e.g.,
it is transparent), the surfaces can be examined directly using
microscopy or electron microscopy to determine the amount of
particles present at the exposed surface or adjacent to the
substrate.
[0025] Embodiments of the coatings described herein are durable in
that they can withstand some amount of abrasion without a
substantial loss of HP/OP properties. To provide an endpoint for
the loss of superhydrophobic (SH) behavior as a result of abrasion
testing, substantially planar abraded surfaces are tested for their
propensity to shed water droplets at an indicated angle of incline
(5 degrees unless indicated otherwise). Typically, twenty droplets
are placed on the surface to be assessed, which is inclined at the
desired angle. The end of SH behavior is indicated when more than
half (ten or more drops) stay in place. While such measurements
provide a consistent endpoint, a skilled artisan will understand
that, even when the endpoint is reached, the abraded surfaces may
still be quite hydrophobic, e.g., having water contact angles
greater than 130.degree. or 140.degree. in many instances.
[0026] Resistance to abrasion may be measured using any method
known in the art including, but not limited to, mechanized or
manual assessment with a Taber abrasion-testing instrument (e.g., a
Taber "Abraser") or a Crockmeter. Alternatively, a manual measure
used to assess the durability of surfaces is a glove rub (GR) test.
Each of those tests is described in more detail below.
[0027] For the purpose of this application, wherever Taber testing
results are recited, the tests are conducted on a Taber Model 503
instrument using CS-0 or CS10 wheels with 250 g or 1,000 g loads as
indicated. Unless indicated otherwise, a load of 1,000 g was
employed, and tests were conducted at room temperature at a speed
of 95 rpm.
[0028] Where resistance to the loss of HP is measured with a
Crockmeter, a motorized American Association of Textile Chemists
and Colorists (AATCC) CM-5 Crockmeter is employed. The finger of
the Crockmeter is fitted with a 14/20 white rubber septum having an
outside diameter of 13 mm and an inside diameter of 7 mm with a
contact surface area of 94 mm.sup.2 (Ace Glass, Inc., Vineland,
N.J., Catalog No. 9096-244). The septum is brought into contact
with the coating with a force of 9N (Newtons). The end of
superhydrophobic behavior is judged by the failure of more than
half of the water droplets applied to the tested surface (typically
20 droplets) to run (roll) off when the surface is inclined at 5
degrees from horizontal. Abrasion resistance may also be measured
using a manually operated AATCC Crockmeter.
[0029] Although an absolute correlation between Taber Abraser
Testing, Crockmeter testing, and glove-rub testing is not provided,
the manual glove-rub test is useful as an indication of the
durability of the coated surface and its ability to be handled.
Coatings applied to primed surfaces incorporating rigid particles
(e.g., EXTENDO SPHERES) typically give a ratio of about 4.5 glove
rubs/Taber Abraser cycles (250 g load) with CS-0 wheels and a ratio
of about 7.5 glove rubs/Taber cycles with CS-10 wheels. Coatings
incorporating flexible first particles (e.g., black rubber
particles) typically give a ratio of about 7.6 glove rubs/Taber
Abraser cycles (250 g load) with CS-0 wheels and a ratio of about
12.9 with CS-10 wheels. Results are given below for coatings of
several thicknesses, where the thickness measurement includes the
thickness of the primer layer. The number of strokes observed in
Crockmeter testing is generally about one fourth of the number of
"glove rubs" observed in the manual glove rub testing.
Nearly Transparent Coating with Clear Hollow Rigid Thermoplastic
First Particles
TABLE-US-00001 CS-0 Wheel CS-10 Wheel Ratio Ratio Approximate GR/
GR/ Glove Rubs Thickness Taber Taber Thickness Taber Taber to loss
of SH (mils) Cycles cycle (mils) Cycles cycle 500 1.1 130 3.8 1 60
8.3 500 2.1 100 5.0 2 70 7.1 500 3.5 110 4.5 3.5 60 8.3 500 4 110
4.5 4.5 80 6.3
Nontransparent Coating with Flexible Black Rubber First
Particles
TABLE-US-00002 CS-0 Wheel CS-10 Wheel Ratio Ratio Approximate GR/
GR/ Glove Rubs Thickness Taber Taber Thickness Taber Taber to loss
of SH (mils) Cycles cycle (mils) cycles cycle 700 2.7 100 7.0 2.6
60 11.7 700 4.9 90 7.8 4.8 50 14 700 7.5 90 7.8 7.2 50 14 700 9.5
90 7.8 8.5 60 11.7
[0030] In addition to resisting the loss of HP/OP properties from
abrasion, the compositions provided herein also provide durability
in the form of resistance to other conditions. The coatings also
resist loss of those properties when subject to: [0031] Submersion
in water (the duration a coating resists wetting at different
depths in water); [0032] Flowing water (the ability of a coating or
surface treatment to resist the impact of flowing water such as a
shower of water); [0033] Exposure to liquids other than water
(chemical durability and resistance to acids, alkalis, salts, and
certain organic solvents such as alcohols); [0034] Ultraviolet (UV)
radiation; [0035] Boiling water; and [0036] Salt water, in the form
of immersion, spray, or fog.
[0037] The elastomer-based coatings described herein have a variety
of properties in addition to resisting the loss of HP/OP from
abrasion including, but not limited to, resisting ice formation
and/or adherence on the coating and flexibility over a wide range
of temperatures (e.g., -35.degree. C. to 205.degree. C.).
[0038] In one embodiment, the HP/OP elastomeric coatings comprising
plastic, glass or rubber first particles (e.g., EXPANCEL spheres or
micronized rubber) have a relative electrical permittivity at 100
MHz from about 0.2 to about 4 at about 22.degree. C. (e.g., a
permittivity from about 0.2 to about 1, from about 1 to about 2,
from about 2 to about 3, or from about 3 to about 4) as measured by
ASTM D150 using a single 0.11 mm thick film, or three layers of
0.11 mm film to achieve a 0.33 mm thickness.
[0039] In addition to their other properties, the HP/OP coatings
described herein can be described by their characteristic roughness
that may be measured by any means known in the art. In some
embodiments, the surface roughness is measured using a Mahr Pocket
Surf PS1 (Mahr Federal Inc., Providence, R.I.). The roughness of a
surface can be expressed using a variety of mathematical
expressions including, but not limited to, its Arithmetical Mean
Roughness and its Ten-Point Mean Roughness.
[0040] The coatings resulting from the application of the
compositions provided for herein have in some embodiments a surface
with an arithmetical mean roughness in a range selected from:
greater than about 3 microns to about 4 microns; from about 4
microns to about 6 microns; from about 4 microns to about 8
microns; from about 4 microns to about 12 microns; from about 4
microns to about 20 microns; from about 5 microns to about 10
microns; from about 5 microns to about 12 microns; from about 5
microns to about 20 microns; from about 6 microns to about 10
microns; or from about 6 microns to about 14 microns.
[0041] In other embodiments, the coatings, resulting from the
application of the compositions provided for herein, have in some
embodiments a surface with a ten point mean roughness selected
from: from about 7 microns to about 60 microns; from about 7
microns to about 70 microns; from about 7 microns to about 80
microns; from about 7 microns to about 100 microns; from about 8
microns to about 60 microns; from about 8 microns to about 80
microns; from about 8 microns to about 100 microns; from about 12
microns to about 60 microns; from about 12 microns to about 100
microns; from about 15 microns to about 60 microns; or from about
15 microns to about 100 microns.
[0042] A more complete discussion of the coating compositions,
their methods of preparation and application, and their properties
follows. A skilled artisan will understand that the description and
examples set forth herein are provided as guidance, and are not
limiting to the scope of the methods and compositions described
herein.
1.0 DEFINITIONS
[0043] For the purposes of this disclosure, a HP material or
surface is one that results in a water droplet forming a surface
contact angle exceeding about 90.degree. at room temperature (which
is about 18.degree. C. to about 23.degree. C. for purposes of this
disclosure). Similarly, for the purposes of this disclosure, a SH
material or surface is one that results in a water droplet forming
a surface contact angle exceeding 150.degree. but less than the
theoretical maximum contact angle of 180.degree. at room
temperature. As SH surface behavior encompasses water contact
angles from about 150.degree. to about 180.degree., SH behavior is
considered to include what is sometimes referred to as
"ultrahydrophobic" behavior. For the purpose of this disclosure the
term hydrophobic (HP) shall include superhydrophobic (SH) behavior
unless stated otherwise, and any and all embodiments, claims, and
aspects of this disclosure reciting hydrophobic behavior may be
limited to either hydrophobic behavior that is not superhydrophobic
(contact angles from 90.degree.-150.degree.) or superhydrophobic
behavior (contact angles of 150.degree. or greater).
[0044] For the purposes of this disclosure an OP material or
surface is one that results in a droplet of light mineral oil
forming a surface contact angle exceeding about 90.degree..
Similarly, for the purposes of this disclosure a SOP material or
surface is one that results in a droplet of light mineral oil
forming a surface contact angle exceeding 150.degree. but less than
the theoretical maximum contact angle of 180.degree. at room
temperature. For the purpose of this disclosure the term oleophobic
(OP) shall include superoleophobic (SOP) behavior unless stated
otherwise, and any and all embodiments, claims, and aspects of this
disclosure reciting oleophobic behavior may be limited to either
oleophobic behavior that is not superoleophobic (contact angles
from 90.degree.-150.degree.) or superoleophobic behavior (contact
angles of 150.degree. or greater).
[0045] Anti-icing (AI) surfaces are surfaces that are resistant to
ice formation and/or accretion in dynamic testing, or that prevent
ice that forms from adhering to the surface (i.e., ice that forms
can be removed with less force than from untreated metal
surfaces).
[0046] For the purpose of this disclosure, HP/OP denotes
hydrophobic behavior (including superhydrophobic behavior) or
properties and/or oleophobic (including superoleophobic behavior)
behavior or properties. HP/OP behavior may be understood to include
anti-icing properties and any embodiment recited as having HP/OP
behavior may be recited as having anti-icing properties, unless
stated otherwise in this disclosure.
[0047] Durability, unless stated otherwise, refers to the
resistance to loss of superhydrophobic or superoleophobic
properties due to mechanical abrasion.
[0048] Alkyl as used herein denotes a linear or branched alkyl
radical or group. Alkyl groups may be independently selected from
C.sub.1 to C.sub.20 alkyl, C.sub.2 to C.sub.20 alkyl, C.sub.4 to
C.sub.20 alkyl, C.sub.6 to C.sub.18 alkyl, C.sub.6 to C.sub.16
alkyl, or C.sub.6 to C.sub.20 alkyl. Unless otherwise indicated,
alkyl does not include cycloalkyl.
[0049] Cycloalkyl as used herein denotes a cyclic alkyl radical or
group. Cycloalkyl groups may be independently selected from:
C.sub.4 to C.sub.20 alkyl comprising one, two, or more C.sub.4 to
C.sub.8 cycloalkyl functionalities; C.sub.6 to C.sub.20 alkyl
comprising one, two, or more C.sub.4 to C.sub.8 cycloalkyl
functionalities; C.sub.6 to C.sub.20 alkyl comprising one, two, or
more C.sub.4 to C.sub.8 cycloalkyl functionalities; C.sub.5 to
C.sub.18 alkyl comprising one, two, or more C.sub.4 to C.sub.8
cycloalkyl functionalities; C.sub.6 to C.sub.18 alkyl comprising
one, two, or more C.sub.4 to C.sub.8 cycloalkyl functionalities; or
C.sub.6 to C.sub.16 alkyl comprising one, two or more C.sub.4 to
C.sub.8 cycloalkyl functionalities. Where two or more cycloalkyl
groups are present they may be present as fused rings or in a spiro
configuration. One or more hydrogen atoms of the cycloalkyl groups
may be replaced by fluorine atoms.
[0050] Haloalkyl as used herein denotes an alkyl group in which
some or all of the hydrogen atoms present in an alkyl group have
been replaced by halogen atoms. Halogen atoms may be limited to
chlorine or fluorine atoms in haloalkyl groups.
[0051] Fluoroalkyl as used herein denotes an alkyl group in which
some or all of the hydrogen atoms present in an alkyl group have
been replaced by fluorine atoms.
[0052] Perfluoroalkyl as used herein denotes an alkyl group in
which fluorine atoms have been substituted for each hydrogen atom
present in the alkyl group.
[0053] Rubber phase as used herein denotes a portion of styrene
block copolymers having synthetic rubber attributes. In SBCs rubber
phases are typically flanked or joined by polystyrene units that
may function as end blocks. Typical synthetic rubbers include an
isoprenoid or a polyolefin such as polybutadiene, polyisoprene, or
ethylene/butylene.
[0054] For the purpose of this disclosure, unless stated otherwise,
when content is indicated as being present on a "weight basis," the
content is measured as the percentage of the weight of the
components indicated to the total weight of the composition
(including recited/required solvents). Optional solvents are not
included in the weight of the composition.
[0055] "Colorant" as used herein is a material added to the coating
composition to cause a change in color, i.e., become colored.
Colorants can be dyes which bind at least a portion of the material
to be colored, insoluble pigments that are dispersed in at least a
portion of the material to be colored, colored chemicals that are
dispersed or dissolved in at least a portion of the material to be
colored, or inks, which may be any combination of dyes, pigments
and colored chemicals. In some embodiments, first or second
particles may comprise colorants or may be prepared from materials
that are colored.
2.0 ELASTOMERIC BINDERS
[0056] Elastomers are polymers that are elastic (i.e., have
viscoelasticity), and which generally have a low Young's modulus
and high yield strain compared with other materials. Elastomers may
be thermoset materials, which require vulcanization (e.g., covalent
crosslinking) during curing, or thermoplastic materials
(thermoplastic elastomers), in which the crosslinks are weaker
dipole or hydrogen bonds.
[0057] Elastomeric binder systems employed to make elastomeric
coatings (elastomer based coatings) having HP/OP properties are
typically comprised of copolymers of polystyrene and a rubber (a
rubber phase) known as Styrenic Block Copolymers (SBCs). SBCs are a
class of thermoplastic elastomers consisting of a two-phase
structure of hard polystyrene end blocks and soft rubber midblocks.
The polystyrene end blocks associate to form domains that lock the
molecules into place without vulcanization. Since this is a
reversible process, the material can be processed on conventional
thermoplastic equipment or dissolved in a suitable solvent for
application as a coating. Polystyrene end blocks impart strength
and the rubber phase mid-blocks impart elasticity. FIG. 1 shows a
schematic of a typical SBC copolymer, where the rubber phase is
linked to the polystyrene phase. In SBCs the rubber phase can be a
synthetic rubber such as, for example, ethylene/butylene (EB e.g.,
--[CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH(CH.sub.2CH.sub.3)CH.sub.2].sub.n--)
ethylene/propylene (EP, e.g.,
--[CH.sub.2CH.sub.2CH(CH.sub.3)CH.sub.2].sub.n--), polybutadiene,
polyisoprene, or polyolefin (see FIG. 1). FIG. 2 shows that the
copolymers can have various spatial orientations such as linear,
radial, or star like.
[0058] SBC compositions, when used as a base coating, produce
highly durable HP/OP coatings as measured by a variety of different
methods, including those described herein. Moreover, the coatings
are compatible with and adhere tightly to a broad range of
materials, permitting a large number and type of objects and
substrates to be coated.
[0059] SBC elastomers offer a variety of advantages and properties
for the preparation of base coats used to prepare HP/OP coatings.
As they can be dissolved/suspended in a number of solvents, they
may be formulated into compositions that are amenable to
application using standard equipment including conventional spray
guns and aerosol canisters (e.g., an aerosol spray container
comprises a valve assembly, a dip tube, and an actuator). As a base
coating composition for use in a multi-step (e.g., two-step,
three-step, four-step . . . ) HP/OP coating process, SBC elastomer
formulations offer flexibility during application and in the
application of the second component of the HP/OP coating process.
The elastomeric first component can be applied to form a base
coating and the second component, which comprises second particles
whose application renders the coating HP/OP, can be applied to the
base coating when it is wet, tacky, dry to touch, or even
completely dried and cured.
[0060] A variety of SBCs may be employed to prepare the HP/OP
coatings described herein. In an embodiment the SBC-containing
binder compositions comprise a rubber phase comprising
ethylene/butylene (EB e.g.,
--[CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH(CH.sub.2CH.sub.3)CH.sub.2].sub.n--)-
. In another embodiment, the SBC-containing binder compositions
comprise a rubber phase comprising (poly)butadiene (e.g.,
styrene-butadiene-styrene (SBS) elastomeric polymers. In other
embodiments, the rubber phases of suitable SBC polymer compositions
comprise ethylene/propylene (EP e.g.,
--[CH.sub.2CH.sub.2CH(CH.sub.3)CH.sub.2].sub.n--), polybutadiene,
polyisoprene or polyolefin. In another embodiment, binder
compositions used for the preparation of durable HP/OP coatings
comprise a mixture of any two, three, or four SBC elastomers having
rubber phases comprising: ethylene/butylene butadiene,
ethylene/propylene polybutadiene, polyisoprene or polyolefin.
[0061] Elastomeric coatings with an elongation at break that is
greater than about 500%, 600%, 700%, 750%, or about 800% are
generally desirable as binders for preparing the durable HP/OP
coatings (e.g., coatings prepared with "Kraton G" elastomers),
although elastomeric coating compositions with lower elongation at
break values can be employed. The rubber component in the SBC
copolymers of such elastomer compositions typically varies from
about 69% to about 87%, but the rubber component may be about 65%
to about 90%, about 67% to about 75%, about 75% to about 87%, or
about 70% to about 80% (based on the weight of the SBC
copolymer(s)). Among the commercially available SBC elastomer
compositions that can be employed as binders for the HP/OP coating
compositions described herein are those developed by KRATON.RTM.
Polymers U.S. LLC. (Houston, Tex.). Various elastomeric polymers,
compositions, and their properties are described, for example, in
the KRATON.RTM. Polymers' Fact Sheet K0151 Americas available on
the world wide web at:
docs.kraton.com/kraton/attachments/downloads/82021AM.pdf.
[0062] In one embodiment the elastomers employed as binders may be
ethylene butylene (EB) elastomeric polymers which have styrene
domains (endblocks) and ethylene/butylene rubber phase midblocks.
Such EB elastomers may comprise about 65% to 75% rubber phase
midblocks, (e.g., about 65%, about 70% or about 75% rubber phase
midblocks) and have an elongation at break of 500 to 800% using
ASTM D412 on films cast from toluene solution with the grip
separation speed set at 10 inches per minute. Some properties of
KRATON.RTM. EB elastomers are detailed in Table 1.
[0063] In one embodiment the elastomers employed as binders may be
styrene-butadiene-styrene (SBS) elastomeric polymers. Such SBS
elastomers comprise about 60% to 74% butadiene by weight, and have
an elongation at break of from 800 to 900% using ASTM D412 on films
cast from toluene solution with the grip separation speed set at 10
inches per minute. Some properties of KRATON.RTM.
styrene-butadiene-styrene (SBS) elastomeric polymers (KRATON.RTM. D
SBS) are detailed in Table 2.
TABLE-US-00003 TABLE 1 EB Based Polymers* G1633 G1650 G1651 G1652
G1654 G1657 G1660 G1726 (SEBS) (SEBS) (SEBS) (SEBS) (SEBS) (SEBS)
(SEBS) (SEBS) Property Linear Linear Linear Linear Linear Linear
Linear Linear Tensile Strength, -- 35 >28 31 >28 23 32 2
MPa.sup.1,2 300% Modulus -- 5.6 -- 4.8 2.4 5.5 -- MPa.sup.1,2
Elongation at -- 500 >800 500 800 750 800 200 Break, %.sup.1,2
-- 70 70 70 70 47 68 70 Specific Gravity 0.91 0.91 0.91 0.91 0.91
0.89 0.91 0.91 Brookfield Viscosity, cps at 25.degree. C. 25% w4 --
8,000 >50,000 1,800 >50,000 4,200 8,000 200 10% w4 -- 50
1,800 30 410 65 50 10 -Melt Index g/10 min. <1 <1 <1 <1
<1 <8 <1 65 (5 kg) 200.degree. C. 230.degree. C. <1
<1 <1 5 <1 22 <1 <100 Styrene/Rubber 30/70 30/70
30/70 30/70 33/67 13/87 31/69 30/70 Ratio Fluffy Powder/ Powder/
Powder/ Powder/ Dense Powder Dense Physical Form Crumb Fluffy
Fluffy Fluffy Fluffy Pellet Pellet Crumb Crumb Crumb Crumb Diblock,
% -- <1 <1 <1 <1 29 -- 70 Comments FDA FDA FDA FDA FDA
FDA FDA FDA *polymers recited in this table supplied by KRATON
.RTM. .sup.1ASTM method D412 tensile tester grip separation speed
10 in./min. .sup.2Typical properties determined on film cast from
toluene solution. .sup.3Typical values on polymer compression
molded at 177.degree. C. .sup.4Neat Polymer concentration in
toluene
TABLE-US-00004 TABLE 2 SBS Elastomeric Polymers* D0243 D1101 D1102
D1116 D1118 D1133 D1152 D1153 (SBS) (SBS) (SBS) (SBS) (SBS) (SBS)
(SBS) (SBS) Property Di-block Linear Linear Radial Diblock Linear
Linear Linear Tensile Strength, 2 32 32 32 2 21 32 28 MPa.sup.1.2
300% Modulus, 1.0 2.8 2.8 2.4 1.2 2.1 2.8 2.9 MPa.sup.1.2
Elongation at -- 880 880 900 600 800 900 800 Break, %.sup.1.2 Set
at Break, -- 10 10 10 40 20 10 -- %.sup.1.2 Hardness, 70 69 66 63
64 74 66 70 Shore A (10 sec.).sup.3 Specific Gravity 0.94 0.94 0.94
0.94 0.94 0.94 0.94 0.96 Brookfield 315 4,000 1,100 9,000 630 4,800
1,000 1,650 Viscosity, cps at 25.degree. C. (25% w) Brookfield --
-- -- 2,500 -- 420 -- -- Viscosity, cps at 25.degree. C. (15% w)
Melt Index 20 <1 14 <1 10 <1 8 3 g/10 min. (200.degree.
C./5 kg) Styrene/Rubber 33/67 31/69 28/72 23/77 33/67 36/64 29/71
Ratio Physical Form Porous Porous Porous Porous Porous Porous
Porous Porous Pellet Pellet Pellet Pellet Pellet Pellet Pellet
Pellet Powder Powder Powder Powder Diblock, % 75 16 17 16 78 34 15
<1 D1155 D1184 D1186 D1189 D1191 D1192 DX405 (SBS) (SBS) (SBS)
(SBS) (SBS) (SBS) (SBS) Property Linear Radial Radial Radial Radial
Linear Linear Tensile Strength, 28 28 25 -- -- -- -- MPa.sup.1.2
300% Modulus, 2.9 5.5 3 -- -- -- -- MPa.sup.1.2 Elongation at 800
820 800 -- -- -- -- Break, %.sup.1.2 Set at Break, -- 10 10 -- --
-- -- %.sup.1.2 Hardness, 87 68 74 68 68 66 53 Shore A (10
sec.).sup.3 Specific Gravity 0.94 0.94 0.94 0.94 0.94 0.94 0.94
Brookfield 600 >20,000 -- TBD.sup.5 >20,000 1,500 v
Viscosity, cps at 25.degree. C. (25% w) Brookfield -- 1,100 1,200
TBD 1,100 -- 2,000 Viscosity, cps at 25.degree. C. (15% w) Melt
Index 14 <1 <1 <1 <1 <1 3 g/10 min. (200.degree.
C./5 kg) Styrene/Rubber 40/60 31/69 30/70 31/69 33/69 30/70 24/76
Ratio Physical Form Porous Porous Porous Porous Porous Porous
Porous Pellet Pellet Pellet Pellet Pellet Pellet Pellet Powder
Powder Powder Powder Powder Diblock, % <1 16 10 16 18 <1
<1 *polymers recited in this table supplied by KRATON .RTM.
.sup.1ASTM method D412 grip separation speed 10 in./min.
.sup.2Typical properties determined on film cast from toluene
solution .sup.3Typical values on polymer compression molded at
177.degree. C. .sup.4Neat polymer concentration in toluene
.sup.5TBD--To Be Determined
[0064] In another embodiment the elastomers employed as binders may
be maleated styrene-ethylene/butylene-styrene (SEBS) elastomeric
polymers. Such maleated SEBS elastomers comprise about 65% to about
90% (e.g., about 70% or about 87%) rubber midblocks by weight, and
have an elongation at break of 500 to 750% using ASTM D412 on films
cast from toluene solution with the grip separation speed set at 10
inches per minute. Maleated SEBS polymers typically have from about
0.8% to about 2.2% (e.g., 0.9% to 2.1% or 1% to 1.7%) of
substitution. Some properties of KRATON.RTM.
styrene-ethylene/butylene-styrene (SEBS) elastomeric polymers
(KRATON.RTM. FG Polymers) are detailed in Table 3.
TABLE-US-00005 TABLE 3 Maleated SEBS Polymers FG Polymer Grades*
FG1901 (SEBS) FG1924 (SEBS) Property Linear Linear Tensile
Strength, MPa.sup.1 34 23 300% Modulus, MPa.sup.1 -- -- Elongation
at Break, %.sup.1 500 750 Hardness, Shore A (10 sec).sup.2 71 49
Specific Gravity 0.91 0.89 Brookfield Viscosity, 25% w 5,000 19,000
(toluene solutions) cps at 25.degree. C. 110 270 10% w Melt Index
g/10 min (5 kg) 200.degree. C. 5 11 230.degree. C. 22 40
Styrene/Rubber Ratio 30/70 13/87 Physical Form Dense Pellet Dense
Pellet Comments FDA.sup.3 1.0% bound 1.7% bound functionality
functionality *polymers recited in this table supplied by KRATON
.RTM. .sup.1ASTM method D412-tensile tester grip separation speed
10 in./min. .sup.2Typical values on polymer compression molded at
177.degree. C.
[0065] In one embodiment the elastomeric binder comprises triblock
copolymers of styrene and ethylene/butylene with a polystyrene
content of: about 8% to about 14%, about 12% to about 20%, about
18% to about 28%, about 22% to about 32%, about 26% to about 36%,
about 8%, about 9%, about 10%, about 11%, about 12%, about 13%,
about 14%, about 16%, about 18%, about 19%, about 20%, about 22%,
about 24%, about 26%, about 28%, about 30%, about 32%, about 34%,
about 36% or mixtures of any two or more, three or more, or four or
more of such triblock copolymers. Any one or more of such triblock
copolymers may optionally comprise 1% to 3%, 1.4% to 2.0%, 1% to
1.4%, 1.6% to 3%, or 2% to 3% of bound maleic anhydride (maleated
copolymers) and may be linear triblock copolymers. In one such
embodiment the binder comprises two different maleated triblock
copolymers of styrene and ethylene/butylene with a polystyrene: a
first triblock copolymer of styrene and ethylene/butylene with a
polystyrene having 0.4% to 1.6% (e.g., 0.5% to 1.5%, 0.6% to 1.4,%
or 0.7% to 1.3%) substitution by maleic anhydride by weight of the
first triblock copolymer (and optionally less than 0.3% maleic
anhydride free); and a second triblock copolymer of styrene and
ethylene/butylene with a polystyrene having 1.1% to 2.5% (e.g., 1.3
to 2.3 or 1.4 to 2.4%) substitution by maleic anhydride by weight
of the second triblock copolymer. In such an embodiment the first
and/or second triblock copolymers may be linear or branched
copolymers (e.g., arborols or dendrimers), and the second triblock
copolymers may be present in a weight ratio from about 4:1 to about
6.5:1 (e.g., the first copolymer to second copolymer ratio is about
4:1 to about 5.5:1, about 5:1 to about 6:1, or about 5.5:1 to about
6.5:1).
[0066] Persons skilled in the art will also recognize other
elastomeric binders that may be used in place of or in addition to
the elastomeric binders described in this disclosure.
[0067] In addition to comprising elastomeric polymers (e.g., SBCs),
first particles and solvents, elastomeric binder systems that serve
as first components optionally comprise a tackifier. Tackifiers may
be present in any suitable amount, including in a range selected
from about or from about 0.5% to about 30%; 1% to about 5%, from
about 2% to about 8%, from about 3% to about 7%, from about 5% to
about 10%, from about 10% to about 15%, from about 15% to about
20%, from about 20% to about 25%, or from about 25% to about 30%.
Some suitable tackifiers, including totally synthetic (e.g.,
members of the Regalrez.RTM. family from Eastman Chemical) or
modified resins or rosins are set forth in the section describing
primers that follows.
[0068] First components, and primers discussed below, may further
comprise light stabilizers and UV absorbers (UV stabilizers), fire
retardants, and/or antioxidants. For example, Tinuvin.RTM. light
stabilizing products (e.g., Tinuvin 328 and/or Tinuvin 770DF)
produced by BASF.RTM., and/or IRGANOX.RTM. antioxidant products
(e.g., phenolic or hindered phenolic antioxidants such as
IRGANOX.RTM. 1520 or IRGANOX.RTM. 150L) produced by BASF.RTM. may
be included in the first component binder composition used to set
down the base coat or in a primer. Where light/UV stabilizers, UV
absorbers, fire retardants, and/or antioxidants are added to either
or both of the first component or the primer, they are generally
added in an amount less than 2% by weight (e.g., about 1%, 0.75%,
0.5%, 0.4%, 0.3%, 0.2% 0.1%, 0.075%, 0.06%, or 0.05%, or in a range
selected from about 0.01% to about 2%, from about 0.05% to about
1.0%, or from about 0.75% to about 0.5% by weight), and take the
place of a corresponding weight of any solvents that may be
present.
[0069] In addition to the ease of application, elastomer based
coatings that do not contain a colorant or significant amounts of
opaque particles are nearly transparent to visible light. Typical
light transmission (Total Luminous Transmittance or "TLT") of an
elastomeric binder coating prepared using SBCs having 15 micron
thickness is approximately 90% (about 85% to about 92%) with a haze
of about 61% (about 55% to about 65%). HP/OP coatings without added
colorants that are about 25 microns thick prepared with clear first
particles (e.g., EXPANCEL particles or other plastic or glass
particles or hollow spheres) and fumed silica second particles
treated with a silane (silanizing agent) can be nearly transparent.
Such HP/OP coatings typically have a TLT of about 80% (about 75% to
about 85%) with a haze of about 90% (about 85% to about 90%) as
measure by ASTM D1003-11. For the measurements the instrument was
calibrated against air and glass sample blanks and given a TLT of
about 90% to about 91% and a haze of about 0.2%. Excluding or
removing fine particulate materials such as talc used to increase
the properties of commercially available elastomer compositions
(e.g., flowability of bulk particulates) may increase TLT and haze
values. Such fine particulates used in bulk elastomers may be
removed by washing with a suitable solvent or by omitting the
material from the elastomer compositions when they are
prepared.
[0070] A variety of solvents may be employed to dissolve
elastomeric binders for the preparation of coating compositions
used to prepare the base coat of HP/OP coatings described herein.
In some embodiments, the copolymers are dissolved in solvents
selected from: methyl ethyl ketone (MEK), ethyl acetate, toluene,
1-chloro-4-(trifluoromethyl)-benzene, xylene or mixed xylenes
(including technical grade xylenes), isopropyl acetate,
1,1,1,-trichloroethane, methyl isobutyl ketone (MIBK), tertbutyl
acetate (t-butyl acetate), cyclohexane, methyl-cyclohexane, or
mixtures comprising any two, three, four or more thereof. In one
embodiment the solvent(s) are selected from those found in the
solubility chart shown in FIG. 3, or mixtures of any two, three,
four or more thereof. In another embodiment, the solvent comprises
greater than 50%, 60%, 70%, 80%, 90%, 95%, 98% or 99% of a xylene
(1,2-xylene, 1,3-xylene, or 1,4-xylene) or a mixture of any two or
all three xylenes and optionally ethyl benzene (e.g., a technical
grade of xylene comprising 34%-47% 1,3-xylene, 9%-21% 1,4-xylene,
4%-16% 1,2-xylene, 9%-10% ethylbenzene, 0%-1% toluene, and 0%-1%
benzene).
[0071] In any of the foregoing embodiments, particularly where
coatings are to be nearly transparent, the elastomeric binder
components comprise at most insubstantial amounts (e.g., less than
about 0.5% by weight of the polymers present in the binder) of
colorants or particulates that are insoluble in solvents that
dissolve the elastomeric polymers and/or that would block the
transmission of visible light. One source of such particulates is
materials added for the flowability of bulk polymers in the form of
powders, pellets, or flakes (e.g., talc added to bulk SBCs).
3.0 PARTICLES EMPLOYED IN HP/OP OLEOPHOBIC COATINGS
3.1 First Particles
[0072] Embodiments of the coatings disclosed herein may comprise
particles that are added to the binder compositions to improve the
mechanical properties of the coating, e.g., the durability of the
HP/OP coatings. A wide variety of such particles, which are also
known as extenders or fillers, may be added to the binders. Those
particles are denoted herein as "first particles" because the
coatings described herein may have one or more additional types of
particles. Such first particles that can be employed in the HP/OP
coatings described herein include, but are not limited to,
particles comprising: wood (e.g., wood dust), glass, metals (e.g.,
iron, titanium, nickel, zinc, tin), alloys of metals, metal oxides,
metalloid oxides (e.g., silica), plastics (e.g., thermoplastics),
carbides, nitrides, borides, spinels, diamonds, and fibers (e.g.,
glass fibers).
[0073] Numerous variables may be considered in the selection of
first particles. These variables include, but are not limited to,
the effect the first particles have on the resulting coatings,
their size, their hardness, their compatibility with the binder,
the resistance of the first particles to the environment in which
the coatings will be employed, and the environment the first
particles must endure in the coating and/or curing process,
including resistance to temperature and solvent conditions. In
addition, if light is used for curing the coatings or they are
intended for extended exposure to sunlight, the particles must be
resistant to the required light exposure conditions (e.g.,
resistant to UV light employed in curing or sunlight).
[0074] In embodiments described herein, first particles have an
average size in a range selected from about 1 micron (.mu.m) to
about 300 .mu.m or from about 30 .mu.m to about 225 .mu.m. Within
the broader ranges, embodiments include ranges of first particles
having an average size of from about 1 .mu.m to about 5 .mu.m, from
about 5 .mu.m to about 10 .mu.m, from about 10 .mu.m to about 15
.mu.m, from about 15 .mu.m to about 20 .mu.m, from about 20 .mu.m
to about 25 .mu.m, from about 1 .mu.m to about 25 .mu.m, from about
5 .mu.m to about 25 .mu.m, from about 25 .mu.m to about 50 .mu.m,
from about 50 .mu.m to about 75 .mu.m, from about 75 .mu.m to about
100 .mu.m, from about 100 .mu.m to about 125 .mu.m, from about 125
.mu.m to about 150 .mu.m, from about 150 .mu.m to about 175 .mu.m,
from about 175 .mu.m to about 200 .mu.m, from about 200 .mu.m to
about 225 .mu.m, and from about 225 .mu.m to about 250 .mu.m. Also
included within this broad range are embodiments employing
particles in ranges from about 10 .mu.m to about 100 .mu.m, from
about 10 .mu.m to about 200 .mu.m, from about 20 .mu.m to about 200
.mu.m, from about 30 .mu.m to about 50 .mu.m, from about 30 .mu.m
to about 100 .mu.m, from about 30 .mu.m to about 200 .mu.m, from
about 30 .mu.m to about 225 .mu.m, from about 50 .mu.m to about 100
.mu.m, from about 50 .mu.m to about 200 .mu.m, from about 75 .mu.m
to about 150 .mu.m, from about 75 .mu.m to about 200 .mu.m, from
about 100 .mu.m to about 225 .mu.m, from about 100 .mu.m to about
250 .mu.m, from about 125 .mu.m to about 225 .mu.m, from about 125
.mu.m to about 250 .mu.m, from about 150 .mu.m to about 200 .mu.m,
from about 150 .mu.m to about 250 .mu.m, from about 175 .mu.m to
about 250 .mu.m, from about 200 .mu.m to about 250 .mu.m, from
about 225 .mu.m to about 275 .mu.m, or from about 250 .mu.m to
about 300 .mu.m.
[0075] First particles may be incorporated into the elastomer
binders at various ratios depending on the binder composition and
the first particle's properties. In some embodiments, the first
particles may have a content range selected from about 0.01% to
about 60% or more by weight. Included within this broad range are
embodiments in which the first particles are present, by weight, in
ranges from about 0.02% to about 0.2%, from about 0.05% to about
0.5%, from about 0.075% to about 0.75%, from about 0.1% to about
1%, from about 0.5% to about 2.5%, from about 2% to about 5%, from
about 5% to about 10%, from about 10% to about 15%, from about 15%
to about 20%, from about 20% to about 25%, from about 25% to about
30%, from about 30% to about 35%, from about 35% to about 40%, from
about 40% to about 45%, from about 45% to about 50%, from about 50%
to about 55%, from about 55% to about 60%, and greater than 60%.
Also included within this broad range are embodiments in which the
first particles are present, by weight, in ranges from about 4% to
about 30%, from about 5% to about 25%, from about 5% to about 35%,
from about 10% to about 25%, from about 10% to about 30%, from
about 10% to about 40%, from about 10% to about 45%, from about 15%
to about 25%, from about 15% to about 35%, from about 15% to about
45%, from about 20% to about 30%, from about 20% to about 35%, from
about 20% to about 40%, from about 20% to about 45%, from about 20%
to about 55%, from about 25% to about 40%, from about 25% to about
45%, from about 25% to about 55%, from about 30% to about 40%, from
about 30% to about 45%, from about 30% to about 55%, from about 30%
to about 60%, from about 35% to about 45%, from about 35% to about
50%, from about 35% to about 60%, from about 40% to about 60%, from
about 0.01% to about 5%, from about 0.03% to about 1%, from about
0.05% to about 0.15%, from about 0.1% to about 2.5%, from about
0.2% to about 5%, from about 0.05% to about 10%, from about 0.1% to
about 10%, from about 0.05% to about 15%, or from about 0.05% to
about 20%, on a weight basis.
[0076] In those embodiments where it is desirable to have coatings
that are transparent, substantially transparent, or colored but
transparent, it is generally desirable to employ particles that are
transparent. In one set of embodiments, plastic (e.g.,
thermoplastic) microspheres are employed in the binder systems to
develop surface texture. In another set of embodiments, glass
microspheres are employed in the binder systems to develop surface
texture.
[0077] In one embodiment, substantially spherical thermoplastic
particles are added to the elastomeric binder composition to
develop surface texture (e.g., EXPANCEL microspheres or EXPANCEL
particles). Such microspheres consist of a polymer shell
encapsulating a gas. The average diameter of these hollow spheres
typically ranges from 6 to 45 .mu.m and have a density of 1000 to
1300 kg/m.sup.3 (8.3-10.8 lbs/US Gallon). Upon heating, the
microspheres expand and the volume of the microspheres can increase
more than 40 times (with the diameter changing, for example, from
10 to 40 .mu.m), resulting in a density below 30 kg/m.sup.3 (0.25
lbs/US Gallon). Typical expansion temperatures range from 80 to
190.degree. C. (176-374.degree. F.). When heating the microspheres
the pressure of the gas inside the shell increases and the
thermoplastic shell softens, resulting in a dramatic increase of
the volume of the microspheres. Cooling the microspheres results in
the shell stiffening again and produces lighter (lower density)
expanded microspheres. Some thermoplastic microspheres produced
under the EXPANCEL brand (AkzoNobel, distributed by Eka Chemicals,
Inc., 2240 Northmont Parkway, Duluth, Ga. 30096, USA) are suitable
for use in preparing HP/OP, particularly those that are
substantially transparent. See Table 4.
TABLE-US-00006 TABLE 4 EXPANCEL particles and properties Solid
content Density of Main types Varieties Description [%] EXPANCEL
[kg/m.sup.3] Unexpanded EXPANCEL WU Wet. unexpanded micro- 60-80
1000-1300 microspheres spheres EXPANCEL WUF Wet. unexpanded micro-
60-80 1000-1300 spheres EXPANCEL DU Dry, unexpanded micro- >99
~1000 spheres EXPANCEL DUT Dry, treated, unexpanded microspheres
>99 ~1000 EXPANCEL SL Wet, salted, unexpanded microspheres 40
1200 EXPANCEL SLU Wet, unexpanded micro- 44 1200 spheres EXPANCEL
MB Dry, unexpanded micro- 65 1000 spheres mixed with a matrix,
(EXPANCEL) e.g. EVA Expanded microspheres EXPANCEL WE Wet. expanded
microspheres 15 ~30 EXPANCEL DE Dry, expanded microspheres >99
25-70 EXPANCEL DET Dry, treated, expanded micro- >99 25
spheres
[0078] Where HP/OP coatings capable of withstanding higher
temperatures are desired, and particularly coatings that are
substantially transparent, glass microspheres may be employed in
place of thermoplastic microspheres. Such glass microspheres
include those produced by 3M.TM. (St. Paul, Minn.) or Sphere One,
Inc. (Chattanooga, Tenn.).
[0079] 3.1.1 Exemplary Sources of First Particles
[0080] First particles may be prepared from the diverse materials
described above. Alternatively, first particles may be purchased
from a variety of suppliers. Some commercially available first
particles that may be employed in the formation of the HP/OP
coatings described herein include those in Table 5.
TABLE-US-00007 TABLE 5 First Particles First Particle First
Particle First First Size Crush particle (Filler) Particle Particle
Range Strength Source No. ID Type Details (g/cc) (.mu.m) Color
(psi) Location 1 K1 Glass Bubbles GPS.sup.a 0.125 30-120 White 250
3M .TM..sup.j 2 K15 Glass Bubbles GPS.sup.a 0.15 30-115 White 300
3M .TM..sup.j 3 S15 Glass Bubbles GPS.sup.a 0.15 25-95 White 300 3M
.TM..sup.j 4 S22 Glass Bubbles GPS.sup.a 0.22 20-75 White 400 3M
.TM..sup.j 5 K20 Glass Bubbles GPS.sup.a 0.2 20-125 White 500 3M
.TM..sup.j 6 K25 Glass Bubbles GPS.sup.a 0.25 25-105 White 750 3M
.TM..sup.j 7 S32 Glass Bubbles GPS.sup.a 0.32 20-80 White 2000 3M
.TM..sup.j 8 S35 Glass Bubbles GPS.sup.a 0.35 10-85 White 3000 3M
.TM..sup.j 9 K37 Glass Bubbles GPS.sup.a 0.37 20-85 White 3000 3M
.TM..sup.j 10 S38 Glass Bubbles GPS.sup.a 0.38 15-85 White 4000 3M
.TM..sup.j 11 S38HS Glass Bubbles GPS.sup.a 0.38 15-85 White 5500
3M .TM..sup.j 12 K46 Glass Bubbles GPS.sup.a 0.46 15-80 White 6000
3M .TM..sup.j 13 S60 Glass Bubbles GPS.sup.a 0.6 15-65 White 10000
3M .TM..sup.j 14 S60/HS Glass Bubbles GPS.sup.a 0.6 11-60 White
18000 3M .TM..sup.j 15 A16/ Glass Bubbles Floated 0.16 35-135 White
500 3M .TM..sup.j 500 Series 16 A20/ Glass Bubbles Floated 0.2
30-120 White 1000 3M .TM..sup.j 1000 Series 17 H20/ Glass Bubbles
Floated 0.2 25-110 White 1000 3M .TM..sup.j 1000 Series 18 D32/
Glass Bubbles Floated 0.32 20-85 White 4500 3M .TM..sup.j 4500
Series 19 Expancel 551 Plastic Micro- Dry 0.042 .+-. 0.004 30-50
AkzoNobel.sup.i DE spheres Expanded 40 d42 20 Expancel 551 Plastic
Micro- Dry 0.042 .+-. 0.002 30-50 AkzoNobel.sup.i DE 40 d42 .+-. 2
spheres Expanded 21 Expancel 461 Plastic Micro- Dry 0.07 .+-. 0.006
15-25 AkzoNobel.sup.i DE 20 d70 spheres Expanded 22 Expancel 461
Plastic Micro- Dry 0.06 .+-. 0.005 20-40 AkzoNobel.sup.i DE 40 d60
spheres Expanded 23 Expancel 461 Plastic Micro- Dry 0.025 .+-.
0.003 35-55 AkzoNobel.sup.i DET 40 d25 spheres Expanded 24 Expancel
461 Plastic Micro- Dry 0.025 .+-. 0.003 60-90 AkzoNobel.sup.i DET
80 d25 spheres Expanded 25 Expancel 920 Plastic Micro- Dry 0.030
.+-. 0.003 35-55 AkzoNobel.sup.i DE 40 d30 spheres Expanded 26
Expancel 920 Plastic Micro- Dry 0.025 .+-. 0.003 35-55
AkzoNobel.sup.i DET 40 d25 spheres Expanded 27 Expancel 920 Plastic
Micro- Dry 0.030 .+-. 0.003 55-85 AkzoNobel.sup.i DE 80 d30 spheres
Expanded 28 H50/10000 Glass Bubbles Floated 0.5 20-60 White 10000
3M .TM..sup.j EPX Series 29 iMK Glass Bubbles Floated 0.6 8.6-26.7
White 28000 3M .TM..sup.j Series 30 G-3125 Z-Light CM.sup.b 0.7
50-125 Gray 2000 3M .TM..sup.j Spheres .TM. 31 G-3150 Z-Light
CM.sup.b 0.7 55-145 Gray 2000 3M .TM..sup.j Spheres .TM. 32 G-3500
Z-Light CM.sup.b 0.7 55-220 Gray 2000 3M .TM..sup.j Spheres .TM. 33
G-600 Zeeo- CM.sup.b 2.3 1-40 Gray >60000 3M .TM..sup.j spheres
.TM. 34 G-800 Zeeo- CM.sup.b 2.2 2-200 Gray >60000 3M .TM..sup.j
spheres .TM. 35 G-850 Zeeo- CM.sup.b 2.1 12-200 Gray >60000 3M
.TM..sup.j spheres .TM. 36 W-610 Zeeo- CM.sup.b 2.4 1-40 White
>60000 3M .TM..sup.j spheres .TM. 37 SG Extendo- HS.sup.c 0.72
30-140 Gray 2500 Sphere One.sup.f sphere .TM. 38 DSG Extendo-
HS.sup.c 0.72 30-140 Gray 2500 Sphere One.sup.f sphere .TM. 39 SGT
Extendo- HS.sup.c 0.72 30-160 Gray 2500 Sphere One.sup.f sphere
.TM. 40 TG Extendo- HS.sup.c 0.72 8-75 Gray 2500 Sphere One.sup.f
sphere .TM. 41 SLG Extendo- HS.sup.c 0.7 10-149 Off 3000 Sphere
One.sup.f sphere .TM. White 42 SLT Extendo- HS.sup.c 0.4 10-90 Off
3000 Sphere One.sup.f sphere .TM. White 43 SL-150 Extendo- HS.sup.c
0.62 70 Cream 3000 Sphere One.sup.f sphere .TM. 44 SLW-150 Extendo-
HS.sup.c 0.68 8-80 White 3000 Sphere One.sup.f sphere .TM. 45 HAT
Extendo- HS.sup.c 0.68 10-165 Gray 2500 Sphere One.sup.f sphere
.TM. 46 HT-150 Extendo- HS.sup.c 0.68 8-85 Gray 3000 Sphere
One.sup.f sphere .TM. 47 KLS-90 Extendo- HS.sup.c 0.56 4-05 Light
1200 Sphere One.sup.f sphere .TM. Gray 48 KLS-125 Extendo- HS.sup.c
0.56 4-55 Light 1200 Sphere One.sup.f sphere .TM. Gray 49 KLS-150
Extendo- HS.sup.c 0.56 4-55 Light 1200 Sphere One.sup.f sphere .TM.
Gray 50 KLS-300 Extendo- HS.sup.c 0.56 4-55 Light 1200 Sphere
One.sup.f sphere .TM. Gray 51 HA-300 Extendo- HS.sup.c 0.68 10-146
Gray 2500 Sphere One.sup.f sphere .TM. 52 XI0M 512 Thermo-
MPR.sup.d 0.96 10-100 White 508 XIOM plastic Corp..sup.k 53 XIOM
512 Thermo- MPR.sup.d 0.96 10-100 Black 508 XIOM plastic
Corp..sup.k 54 CORVEL .TM. Thermo- Nylon 1.09 44-74 Black ROHM
& Black 78-7001 plastic Powder HASS.sup.g Coating 55
Micro-glass Fibers MMEGF.sup.e 1.05 16 .times. 120 White
Fibertec.sup.h 3082 56 Micro-glass Fibers MMEGF.sup.e 0.53 10
.times. 150 White Fibertec.sup.h 9007D Silane- Treated 57 Tiger
Drylac Polyester Tiger Series 49 crosslinked Drylac with TGIC USA,
Inc..sup.l (triglycidyl isocyanurate) 58 Soft- Rubber based 90,
180, or Various SoftPoint Sand .RTM. 300 colors Indust. Copley, OH
.sup.aGPS--general purpose series .sup.bceramic microspheres
.sup.chollow spheres .sup.dmodified polyethylene resins
.sup.emicroglass milled E-glass filaments .sup.fChattanooga, TN
.sup.gPhiladelphia, PA .sup.hBridgewater, MA .sup.iDistributed by
Eka Chem., Inc., Duluth, GA .sup.jSt. Paul, MN .sup.kWest Babylon,
NY .sup.lSt. Charles, IL
3.2 Second Particles
[0081] The coatings disclosed herein employ second particles (e.g.,
nanoparticles), which are particles that bear, or are associated
with, hydrophobic and/or oleophobic compounds or moieties (i.e.,
moieties that are covalently or non-covalently bound). The
hydrophobic moieties can be introduced by treating the particles to
include moieties such as siloxanes, fluorinated hydrocarbons (e.g.,
partly or fully fluorinated hydrocarbons) or nonfluorinated
hydrocarbons. In an embodiment, second particles suitable for the
preparation of elastomer-based HP/OP coatings have a size from
about 1 nanometer (nm) to about 25 .mu.m and are capable of binding
covalently to one or more chemical moieties (groups or components)
that provide the second particles, and the coatings into which they
are incorporated, hydrophobicity, and when selected to include
fluoroalkyl groups, hydrophobicity and oleophobicity.
[0082] In one embodiment the second particles have a surface area
over 100, 150, 200, 250, or 300 square meters per gram (m.sup.2/g)
of particulate. In another embodiment, where the particles are
fumed silica, the surface area can be about or greater than 150,
175, 200, 225 or 250 m.sup.2/g.
[0083] Second particles having a wide variety of compositions may
be employed in the durable HP/OP coatings described and employed
herein. In some embodiments the second particles will be particles
comprising metal oxides (e.g., aluminum oxides such as alumina,
zinc oxides, nickel oxides, zirconium oxides, iron oxides, or
titanium dioxides), or oxides of metalloids (e.g., metalloid oxides
such as oxides of B, Si, Sb, Te and Ge) such as glass, silica
(e.g., fumed silica), silicates, aluminosilicates, or particles
comprising combinations thereof.
[0084] In some embodiments, the second particles may have an
average size in a range selected from about 1 nm up to about 25
.mu.m or more. Included within this broad range are embodiments in
which the second particles have an average size in a range selected
from: about 1 nm to about 10 nm, from about 10 nm to about 25 nm,
from about 25 nm to about 50 nm, from about 50 nm to about 100 nm,
from about 100 nm to about 250 nm, from about 250 nm to about 500
nm, from about 500 nm to about 750 nm, from about 750 nm to about 1
.mu.m, from about 1 .mu.m to about 5 .mu.m, from about 5 .mu.m to
about 10 .mu.m, from about 10 .mu.m to about 15 .mu.m, from about
15 .mu.m to about 20 .mu.m, from about 20 .mu.m to about 25 .mu.m,
from about 1 nm to about 100 nm, from about 2 nm to about 200 nm,
from about 10 nm to about 200 nm, from about 20 nm to about 400 nm,
from about 10 nm to about 500 nm; from about 40 nm to about 800 nm,
from about 100 nm to about 1 .mu.m, from about 200 nm to about 1.5
.mu.m, from about 500 nm to about 2 .mu.m, from about 500 nm to
about 2.5 .mu.m, from about 1 .mu.m to about 10 .mu.m, from about 2
.mu.m to about 20 .mu.m, from about 2.5 .mu.m to about 25 .mu.m,
from about 500 nm to about 25 .mu.m, from about 400 nm to about 20
.mu.m, from about 100 nm to about 15 .mu.m, from about 1 nm to
about 50 nm, from about 1 nm to about 400 nm, from about 1 nm to
about 500 nm, from about 2 nm to about 120 nm, from about 5 nm to
about 100 nm, from about 5 nm to about 200 nm; from about 5 nm to
about 400 nm; from about 10 nm to about 300 nm; or from about 20 nm
to about 400 nm.
[0085] In the above-mentioned embodiments, the lower size of second
particles may be limited to particles greater than about 20 nm,
about 25 nm, about 30 nm, about 35 nm, about 40 nm, about 45 nm,
about 50 nm, or about 60 nm; and the upper size of second particles
may be limited to particles less than about 20 .mu.m, about 10
.mu.m, about 5 .mu.m, about 1 .mu.m, about 0.8 .mu.m, about 0.6
.mu.m, about 0.5 .mu.m, about 0.4 .mu.m, about 0.3 .mu.m, about 0.2
.mu.m, or about 100 nm.
[0086] Any combination of particle size, particle composition,
surface area, and/or percent composition in the coatings recited
herein may be employed in preparing elastomer-based HP/OP coatings.
Limitations on the upper and lower size of second particles may be
used alone or in combination with any of the above-recited size
limits on particle composition, surface area, percent composition
in the coatings, and the like.
[0087] In some embodiments, the coatings may contain first
particles in any of the above-mentioned ranges subject to either
the proviso that the coatings do not contain only particles (e.g.,
first or second particles) with a size of 25 .mu.m or less, or the
proviso that the coatings do not contain more than an insubstantial
amount of second particles with a size of 25 .mu.m or less
(recognizing that separation processes for particles greater than
25 .mu.m may ultimately provide an unintended, insubstantial amount
of particles that are 25 .mu.m or less). An insubstantial amount of
particles is less than 3% by weight or number of those particles,
but it can also be less than 0.5%, 1%, or 2% wherever recited.
[0088] In other embodiments, second particles have an average size
greater than 30 .mu.m and less than 250 .mu.m, and coatings
comprising those particles do not contain more than insubstantial
amounts of particles (e.g., first and second particles) with a size
of 30 .mu.m or less. In yet other embodiments, the coatings do not
contain only particles (e.g., first and second particles) with a
size of 40 .mu.m or less, or particles with a size of 40 .mu.m or
less in substantial amounts. In addition, in still other
embodiments, the coatings do not contain only particles (e.g.,
first and second particles) with a size of 50 .mu.m or less, or
particles with a size of 50 .mu.m or less in substantial
amounts.
[0089] In other embodiments, such as where the second particles are
prepared by fuming (e.g., fumed silica or fumed zinc oxide), the
second particles may have an average size in a range selected from
about 1 nm to about 50 nm, from about 1 nm to about 100 nm, from
about 1 nm to about 400 nm, from about 1 nm to about 500 nm, from
about 2 nm to about 120 nm, from about 5 nm to about 100 nm, from
about 5 nm to about 200 nm, from about 25 nm to about 100 nm, from
about 30 nm to about 200 nm, from about 5 nm to about 400 nm, from
about 10 nm to about 300 nm, from about 20 nm to about 400 nm, or
from about 50 nm to about 400 nm.
[0090] As indicated above, second particles are treated to
introduce one or more moieties (e.g., groups or components) that
impart HP/OP properties to the particles, either prior to
incorporation into the compositions that will be used to apply
coatings or after incorporation into the coatings. In some
embodiments, the second particles are treated with a silanizing
agent, a silane, a siloxane or a silazane, to introduce
hydrophobic/superhydrophobic and/or oleophobic/superoleophobic
properties to the particles (in addition to any such properties
already possessed by the particles).
[0091] In one embodiment, second particles are silica, silicates,
alumina (e.g., Al.sub.2O.sub.3), titanium oxide, or zinc oxide that
are treated with one or more silanizing agents, e.g., compounds of
formula (I) (below). In other embodiments, second particles are
comprised of silica, silicates, alumina (e.g., Al.sub.2O.sub.3),
titanium oxide, or zinc oxide that are treated with a siloxane. In
another embodiment, the second particles are silica, silicates,
glass, alumina (e.g., Al.sub.2O.sub.3), titanium oxide, or zinc
oxide, treated with a silanizing agent, a siloxane or a silazane.
In another embodiment, the second particles may be a fumed metal or
metalloid (e.g., particles of fumed silica or fumed zinc
oxide).
[0092] In embodiments where a silanizing agent is employed, the
silanizing agent may be a compound of the formula (I):
R.sub.4-nSi--X.sub.n (I)
[0093] where n is an integer from 1 to 3; [0094] each R is
independently selected from [0095] (i) alkyl or cycloalkyl group
optionally substituted with one or more fluorine atoms, [0096] (ii)
C.sub.1 to 20 alkyl optionally substituted with one or more
substituents independently selected from fluorine atoms and C.sub.6
to 14 aryl groups, which aryl groups are optionally substituted
with one or more independently selected halo, C.sub.1 to 10 alkyl,
C.sub.1 to 10 haloalkyl, C.sub.1 to 10 alkoxy, or C.sub.1 to 10
haloalkoxy substituents, [0097] (iii) C.sub.2 to 8 or C.sub.6 to 20
alkyl ether optionally substituted with one or more substituents
independently selected from fluorine and C.sub.6 to 14 aryl groups,
which aryl groups are optionally substituted with one or more
independently selected halo, C.sub.1 to 10 alkyl, C.sub.1 to 10
haloalkyl, C.sub.1 to 10 alkoxy, or C.sub.1 to 10 haloalkoxy
substituents, [0098] (iv) C.sub.6 to 14 aryl, optionally
substituted with one or more substituents independently selected
from halo or alkoxy, and haloalkoxy substituents, [0099] (v)
C.sub.4 to 20 alkenyl or C.sub.4 to 20 alkynyl, optionally
substituted with one or more substituents independently selected
from halo, alkoxy, or haloalkoxy, and [0100] (vi)
--Z--((CF.sub.2).sub.q(CF.sub.3)).sub.r, wherein Z is a C.sub.1 to
12 or a C.sub.2 to 8 divalent alkane radical or a C.sub.2 to 12
divalent alkene or alkyne radical, q is an integer from 1 to 12,
and r is an integer from 1 to 4; [0101] each X is independently
selected from --H, --Cl, --I, --Br, --OH, --OR.sup.2, --NHR.sup.3,
or --N(R.sup.3).sub.2 group; [0102] each R.sup.2 is an
independently selected C.sub.1 to 4 alkyl or haloalkyl group; and
[0103] each R.sup.3 is an independently selected H, C.sub.1 to 4
alkyl, or haloalkyl group.
[0104] In some embodiments, R is an alkyl or fluoroalkyl group
having from 6 to 20 carbon atoms.
[0105] In other embodiments, R is an alkyl or fluoroalkyl group
having from 8 to 20 carbon atoms.
[0106] In other embodiments, R is an alkyl or fluoroalkyl group
having from 10 to 20 carbon atoms.
[0107] In other embodiments, R is an alkyl or fluoroalkyl group
having from 6 to 20 carbon atoms and n is 3.
[0108] In other embodiments, R is an alkyl or fluoroalkyl group
having from 8 to 20 carbon atoms and n is 3.
[0109] In other embodiments, R is an alkyl or fluoroalkyl group
having from 10 to 20 carbon atoms and n is 3.
[0110] In other embodiments, R has the form
--Z--((CF.sub.2).sub.q(CF.sub.3)).sub.r, wherein Z is a C.sub.1 to
12 divalent alkane radical or a C.sub.2 to 12 divalent alkene or
alkyne radical, q is an integer from 1 to 12, and r is an integer
from 1 to 4.
[0111] In any of the previously mentioned embodiments of compounds
of formula (I), the value of n may be varied such that 1, 2 or 3
independently selected terminal functionalities are present. Thus,
in some embodiments, n is 3. In other embodiments, n is 2. In still
other embodiments, n is 1.
[0112] In any of the previously mentioned embodiments of compounds
of formula (I), all halogen atoms present in any one or more R
groups may be fluorine.
[0113] In any of the previously mentioned embodiments of compounds
of formula (I), X may be independently selected from H, Cl,
--OR.sup.2, --NHR.sup.3, --N(R.sup.3).sub.2, or combinations
thereof. In other embodiments, X may be selected from Cl,
--OR.sup.2, --NHR.sup.3, --N(R.sup.3).sub.2, or combinations
thereof. In still other embodiments, X may be selected from --Cl,
--NHR.sup.3, --N(R.sup.3).sub.2 or combinations thereof.
[0114] Any coating described herein may be prepared with one, two,
three, four or more compounds of formula (I) employed alone or in
combination to modify the nano-particles, and/or other components
of the coating including filler-particles. The use of silanizing
agents of formula (I) to modify nano-particles, or any of the other
components of the coatings, will introduce one or more R.sub.3-n
X.sub.nSi-- groups (e.g., R.sub.3Si--, R.sub.2X.sub.1Si--, or
RX.sub.2Si-- groups) where R and X are as defined for a compound of
formula (I). The value of n is 0, 1, or 2, due to the displacement
of at least one "X" substituent and formation of at least one bond
between a nano-particle and the Si atom (the bond between the
nano-particle and the silicon atom is indicated by a dash "--"
(e.g., R.sub.3Si--, R.sub.2X.sub.1Si--, or RX.sub.2Si--
groups).
[0115] In other embodiments, suitable silanizing agents for
modifying the nano-particles used in the coating compositions
generally comprise those with fluorinated or polyfluorinated alkyl
groups (e.g., fluoroalkyl groups) or alkyl groups (hydrocarbon
containing groups) including, but not limited to: [0116]
(tridecafluoro-1,1,2,2-tetrahydrooctyl)silane (SIT8173.0); [0117]
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane (SIT8174.0);
[0118] (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane
(SIT8175.0); [0119]
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane
(SIT8176.0); [0120]
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethyl(dimethylamino)si-
lane (SIH5840.5); [0121]
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)tris(dimethylamino)silane
(SIH5841.7); [0122] n-octadecyltrimethoxysilane (SIO6645.0);
n-octyltriethoxysilane (SIO6715.0); and [0123]
3,3,4,4,5,5,6,6,6-nonafluorohexyldimethyl(dimethylamino)silane
(SIN6597.4) where the designations given in parentheses are the
product numbers from Gelest, Inc., Morrisville, Pa.
[0124] Another group of reagents that can be employed to prepare
first or second particles with hydrophobic and/or oleophobic
properties include [0125]
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane: [0126]
(tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane; [0127]
nonafluorohexyldimethylchlorosilane; [0128]
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane; [0129]
3,3,4,4,5,5,6,6,6-nonafluorohexyldimethyl(dimethylamino)-silane;
[0130] nonafluorohexylmethyldichlorosilane; [0131]
nonafluorohexyltrichlorosilane; [0132]
nonafluorohexyltriethoxysilane; and [0133]
nonafluorohexyltrimethoxysilane.
[0134] In one embodiment, the coating compositions set forth herein
comprise silica second particles treated with
nonafluorohexyltrichlorosilane.
[0135] In addition to the silanizing agents recited above, a
variety of other silanizing agents can be used to alter the
properties of second particles and to provide hydrophobic and/or
oleophobic properties. In some embodiments, second particles may be
treated with an agent selected from dimethyldichlorosilane,
hexamethyldisilazane, octyltrimethoxysilane, or
tridecafluoro-1,1,2,2-tetrahydrooctyl trichlorosilane. In such
embodiments, the second particles may be silica. Silica second
particles treated with such agents may have an average size in a
range selected from about 1 nm to about 50 nm, from about 1 nm to
about 100 nm, from about 1 nm to about 400 nm, from about 1 nm to
about 500 nm, from about 2 nm to about 120 nm, from about 5 nm to
about 150 nm, from about 5 nm to about 400 nm, from about 10 nm to
about 300 nm, from about 20 nm to about 400 nm, or from about 50 nm
to about 250 nm.
[0136] Other agents can be used to modify second particles,
including, but not limited to, one or more of:
polydimethylsiloxane, gamma-aminopropyltriethoxysilane,
Dynasylan.RTM. A (tetraethylorthosilicate), hexamethyldisilazane,
and Dynasylan.RTM. F 8263 (fluoroalkylsilane), any one or more of
which may be used alone or in combination with the silanizing
agents recited herein.
[0137] Two attributes of silanizing agents that may be considered
for the purposes of their reaction with second particles and the
introduction of hydrophobic or oleophobic moieties are the leaving
group (e.g., X groups of compounds of the formula (I)) and the
terminal functionality (e.g., R groups of compounds of the formula
(I)). A silanizing agent's leaving group(s) can determine the
reactivity of the agent with the first or second particle(s), or
other components of the coating, if applied after a coating has
been applied. Where the first or second particles are a silicate or
silica (e.g., fumed silica) the leaving group can be displaced to
form Si--O--Si bonds. Leaving group effectiveness is ranked in the
decreasing order as chloro>methoxy>hydro (H)>ethoxy
(measured as trichloro>trimethoxy>trihydro>triethoxy).
This ranking of the leaving groups is consistent with their bond
dissociation energy. The terminal functionality determines the
level of hydrophobicity that results from application of the silane
to the surface.
[0138] 3.2.1 Some Sources of Second Particles
[0139] Second particles such as those comprising fumed silica may
be purchased from a variety of suppliers including, but not limited
to, Cabot Corp., Billerica, Mass. (e.g., Nanogel TLD201,
CAB-O-SIL.RTM. TS-720 (silica, pretreated with
polydimethylsiloxane), and M5 (untreated silica)) and Evonik
Industries, Essen, Germany (e.g., ACEMATT.RTM. silica such as
untreated HK400, AEROXIDE.RTM. silica, AEROXIDE.RTM. TiO.sub.2
titanium dioxide, and AEROXIDE.RTM. Alu alumina).
[0140] Some commercially available second particles are set forth
in Table 6 along with their surface treatment by a silanizing agent
or polydimethyl siloxane.
TABLE-US-00008 TABLE 6 Some commercially available second particles
Nominal BET Surface Area Product Surface Level of of Base Particle
Product Name Treatment Treatment Product (m.sup.2/g) Size (nm)
Source M-5 None None 200 -- Cab-O-Sil Aerosil .RTM. None None 200
12 Evonik 200 Aerosil .RTM. None None 255 -- Evonik 255 Aerosil
.RTM. None None 300 7 Evonik 300 Aerosil .RTM. None None 380 7
Evonik 380 HP-60 None None 200 -- Cab-O-Sil PTG None None 200 --
Cab-O-Sil H-5 None None 300 -- Cab-O-Sil HS-5 None None 325 --
Cab-O-Sil EH-5 None None 385 -- Cab-O-Sil TS-610
Dimethyldichlorosilane Intermediate 130 -- Cab-O-Sil TS-530
Hexamethyldisilazane High 320 -- Cab-O-Sil TS-382
Octyltrimethoxysilane High 200 -- Cab-O-Sil TS-720
Polydimethylsiloxane High 200 -- Cab-O-Sil Aerosil .RTM.
Polydimethylsiloxane -- 100 14 Evonik R202 Aerosil .RTM.
Hexamethyldisilazane -- 125-175 -- Evonik R504 (HMDS) and
aminosilane Aerosil .RTM. HMDS based on -- 220 -- Evonik R812S
Aerosil .RTM. 300 BET Surface Area is Brunauer, Emmett and Teller
surface area
##STR00001##
[0141] As purchased, the particles may be untreated (e.g., M5
silica) and may not possess any HP/OP properties. Such untreated
particles can be treated to covalently attach one or more groups or
moieties to the particles that give them HP/OP properties, for
example, by treatment with the silanizing agents discussed
above.
[0142] 3.2.2 Dispersants for Second Particles
[0143] Second particles can be applied to a base coating of
elastomeric binder after it has been applied to the surface of an
object (or a part thereof) in the form of a second component having
a composition comprising one or more independently selected second
particles as described above (e.g., second particles having a size
of about 1 nanometer (nm) to about 25 microns (.mu.m) wherein said
particles comprise one or more independently selected alkyl,
haloalkyl, or perfluoroalkyl moieties bound, either directly or
indirectly, to said second particles; wherein said second component
optionally comprises one or more solvents (liquid dispersants).
[0144] If the elastomeric coating has not dried, or has been
subjected to a solvent that dissolves at least the outermost
portion of the binder (e.g., renders it sufficiently tacky), second
particles may be applied directly to the elastomeric binder by
contacting the second particles with the binder. Second particles
may be contacted with the surface by any suitable means, including
spraying them on the surface using a stream of gas (e.g., air,
nitrogen, or an inert gas), exposing the binder coating to
particles suspended in a gas, or contacting the base coat of
elastomeric binder with a fluidized bed of second particles.
[0145] Second particles can also be applied to a base coating of
elastomeric binder in a second coating component that, in addition
to the second particles, contains a solvent (dispersant) that
dissolves, expands or swells the outermost portion of the binder
sufficiently (e.g., renders it tacky) to permit the second
particles to become bound in at least the outermost portion of the
binder base coat. Where second components of the coating
composition comprise a solvent, the second particles are dispersed
in the solvent for application. Second particles, and particularly
smaller second particles (e.g., 1-50 nm or 1-100 nm), may form
aggregates in solvents used as dispersants.
[0146] Suitable solvents include those with a surface energy lower
than water including, but not limited to: alcohols, ketones,
acetone, methyl ethyl ketone (MEK), ethyl acetate, toluene, xylene,
isopropyl acetate, 1,1,1,-trichloroethane, methyl isobutyl ketone
(MIBK), tertbutyl acetate (t-butyl acetate), cyclohexane,
methyl-cyclohexane, or mixtures comprising any two, three, four or
more thereof. In an embodiment, the solvents are non-aqueous (e.g.,
they contain less than 10%, 5%, 4%, 3%, 2%, 1%, or 0.5% of water by
weight or they contain only insubstantial amounts of water).
Solvents that are miscible with water are employed in the second
coating component in another embodiment. In another embodiment, the
solvent comprises a non-aqueous water miscible solvent. In one
embodiment, the solvent employed in the second coating component is
acetone or is comprised of acetone. In another embodiment the
solvent employed in the second coating component is NMP
(N-methylpyrrolidone) or is comprised of NMP. In other embodiments,
the solvent employed in the second coating composition comprises a
mixture of acetone or NMP with water, particularly a minor
proportion of water (e.g., less than about 5%, less than about 4%,
less than about 2%, less than about 1%, or less than about 0.5%
water).
[0147] In one embodiment, the second component of the coating
composition (i.e., the top coat) comprises:
[0148] i) one or more independently selected second particles
having a size of about 1 nanometer to about 25 microns, wherein
said second particles comprise one or more independently selected
alkyl, haloalkyl, or perfluoroalkyl moieties bound, either directly
or indirectly, to said second particles; and
[0149] ii) optionally, one or more independently selected solvents,
wherein when said one or more solvents are present, said second
particles may be present in a weight percent range selected from
(0.1-1, 1.0-2.0, 0.2-2.0, 0.5-1.5, 0.5-2.0, 0.75-2.5, 1.5-2.0,
1.5-2.5, 2.0-3.0, 2.0-3.5, or 2.5-3.5) based on the weight of the
one or more solvents and second particles.
[0150] In another embodiment, the second component of the coating
composition (i.e., the top coat) comprises:
[0151] (i) 0.1 to 3.5 parts by weight (e.g., 0.1-1, 1.0-2.0,
0.2-2.0, 0.5-1.5, 0.5-2.0, 0.75-2.5, 1.5-2.0, 1.5-2.5, 2.0-3.0,
2.0-3.5, or 2.5-3.5) of second particles that comprise one or more
independently selected alkyl, haloalkyl, or perfluoroalkyl moieties
bound, either directly or indirectly, to said second particles, or
one or more siloxanes or silazanes associated with the second
particles;
[0152] (ii) a fluorinated polyolefin, (e.g., a polymer of
tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride,
such as Dyneon.TM. THV); and/or a Fluoroethylene-Alkyl Vinyl Ether
(FEVE) copolymer; and
[0153] (iii) a solvent for a the remainder of a total of 100 parts
by weight.
[0154] In another embodiment, the fluorinated polyolefin (e.g., a
polymer of tetrafluoroethylene, hexafluoropropylene and vinylidene
fluoride, such as Dyneon.TM. THV), if present, comprises from 0.1
to 1.0 parts by weight (e.g., 0.1-0.5, 0.5-1.0, or 0.3-0.7 parts)
of the composition.
[0155] In another embodiment, the Fluoroethylene-Alkyl Vinyl Ether
(e.g., the constituent polymer found in Lumiflon.TM.), if present,
comprises 0.06 to 0.6 parts by weight (e.g., 0.06-0.0.1, 0.1-0.2,
0.2-0.4, or 0.4-0.6 parts) of the composition. In such an
embodiment the FEVE may have an average molecular weight of about
1,000 to 3,000 (e.g., about 1,000-2,000, 2,000-3,000, 1,500-2,500,
or about 1,000, about 1,500, about 2,000, about 2,500, or about
3,000 Dalton). Accordingly, one embodiment of the second component
comprises per 100 parts by weight:
[0156] i) 0.1 to 3.5 parts by weight (e.g., 0.1-1, 1.0-2.0,
0.2-2.0, 0.5-1.5, 0.5-2.0, 0.75-2.5, 1.5-2.0, 1.5-2.5, 2.0-3.0,
2.0-3.5, or 2.5-3.5) of one or more independently selected second
particles having a size of about 1 nanometer to about 25 microns,
wherein said second particles comprise one or more independently
selected alkyl, haloalkyl, or perfluoroalkyl moieties bound, either
directly or indirectly, to said second particles, or one or more
siloxanes or silazanes associated with said second particles;
[0157] ii) 0.1 to 1.0 parts by weight (e.g., 0.1-0.5, 0.5-1.0, or
0.3-0.7 parts) of a fluorinated polyolefin, (e.g., a polymer of
tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride,
such as Dyneon.TM. THV); and/or [0158] 0.06 to 0.6 parts by weight
(e.g., 0.06-0.0.1, 0.1-0.2, 0.2-0.4, or 0.4-0.6 parts) of a
Fluoroethylene-Alkyl Vinyl Ether (FEVE) copolymer, having an
average molecular weight of about 1,000 to 3,000 (e.g., about
1,000-2,000, 2,000-3,000, 1,500-2,500, or about 1,000, 1,500,
2,000, 2,500, or 3,000 Da);
[0159] and
[0160] (iii) one or more solvent for a the remainder of a total of
100 parts by weight.
[0161] Where the solvent employed in second coating compositions
dissolves or renders at least the outermost layer of the
elastomeric binder "tacky," second particles can be introduced into
completely dried and cured base coats of elastomeric binder. That
permits the repair of worn or abraded coatings that have lost HP/OP
behavior over all or part of their surface.
4.0 SURFACE PREPARATION AND PRIMING
[0162] To improve the adherence and performance of the coatings
described herein the surface to be coated, in whole or in part,
should be clean, free of contaminants and capable of supporting the
coatings (e.g., not friable).
[0163] Performance of the coatings in terms of their durability can
be significantly improved by the application of a primer. Any
primer compatible with both the surface of the object and the
elastomeric coating can be employed.
[0164] A variety of primer compositions may be employed. In one
embodiment the primers comprise one or more polymers that are
elastic (i.e., have viscoelasticity), such as those that comprise
the binder used in the first component of the coating compositions
described herein (e.g., SBCs). In one embodiment, the primer
comprises one or more polymers that are elastic (i.e., have
viscoelasticity, e.g., SBCs) and a tackifier. In one embodiment,
the primer is a Plasti Dip.TM. metal primer f938 hp.
[0165] In one embodiment, when a tackifier is employed, it may be
selected from resins (e.g. rosins and their derivates; terpenes and
modified terpenes; aliphatic, cycloaliphatic and aromatic resins
(C5 aliphatic resins, C9 aromatic resins, and C5/C9
aliphatic/aromatic resins); hydrogenated hydrocarbon resins (e.g.,
Regalrez.TM. 1094, Eastman Chemical Co., Kingsport Tenn.), and
mixtures thereof and/or terpene-phenol resins). In one embodiment
the tackifier is an ester of hydrogenated rosin (e.g., FORAL.TM.
105-E ester of hydrogenated rosin).
[0166] In other embodiments the primer is an elastomeric primer
comprising triblock copolymers of styrene and ethylene/butylene and
an ester of a hydrogenated thermoplastic rosin (e.g., FORAL.TM.
105-E, Eastman Chemical). The polystyrene content of the triblock
copolymers will typically be from about 8% to about 14%, from about
12% to about 20%, from about 18% to about 28%, from about 22% to
about 32%, from about 26% to about 36%, about 8%, about 9%, about
10%, about 11%, about 12%, about 13%, about 14%, about 16%, about
18%, about 19%, about 20%, about 22%, about 24%, about 26%, about
28%, about 30%, about 32%, about 34%, or about 36%. Mixtures of any
two or more, three or more, or four or more of such triblock
copolymers may also be employed in the primer composition, and any
one or more of such triblock copolymers may optionally comprise 1%
to 3%, 1.4% to 2.0%, 1% to 1.4%, 1.6% to 3%, or 2% to 3% bound
maleic anhydride (maleated copolymers). Any of the foregoing
triblock copolymers may be linear or branched (e.g., dendrimers or
arborols).
[0167] In one embodiment wherein the elastomeric primer comprises
triblock copolymers of styrene and ethylene/butylene and an ester
of a hydrogenated thermoplastic rosin, the primer comprises two
different maleated triblock copolymers of styrene and
ethylene/butylene with a polystyrene: a first triblock copolymer of
styrene and ethylene/butylene with a polystyrene having 0.4% to
1.6% (e.g., 0.5% to 1.5%, 0.6% to 1.4,% or 0.7% to 1.3%)
substitution of maleic anhydride by weight of the first triblock
copolymer (and optionally less than 0.3% free maleic anhydride);
and a second triblock copolymer of styrene and ethylene/butylene
with a polystyrene having 1.1% to 2.5% (e.g., 1.3 to 2.3 or 1.4 to
2.4%) substitution of maleic anhydride by weight of the second
triblock copolymer. In such an embodiment the first and/or second
triblock copolymers may be linear or branched copolymers (e.g.,
arborols or dendrimers), and the second triblock copolymers may be
present in a weight ratio from about 4:1 to about 6.5:1 (e.g., the
first copolymer to second copolymer ratio is about 4:1 to about
5.5:1, about 5:1 to about 6:1, or about 5.5:1 to about 6.5:1). The
ratio of the total triblock copolymer (first and second) to the
ester of a hydrogenated thermoplastic rosin is typically 1:5 to
2.5:5 (triblock copolymers: ester(s) of hydrogenated thermoplastic
rosin). Ratios for all three components include 7:1:25, 7.2:1.3:25,
7.6:1.6:25, and 8:1.8:25 (first triblock copolymer: second triblock
copolymer: ester of a hydrogenated thermoplastic rosin).
[0168] In any of the foregoing embodiments the primers may also
comprise insubstantial amounts (e.g., less than about 2% by weight
of the polymers present in the binder, such as less than 1.0%,
0.75%, 0.5%, 0.25%, or 0.1%) of colorants or particulates that are
insoluble in the solvents that dissolve the elastomeric polymers
and/or that would block the transmission of visible light in the
dried cured coating (e.g., talc added for the flowability of
particles of the polymers as produced).
[0169] In any of the foregoing embodiments the primers may also
comprise first particles for texture development in the primer
and/or the base coat (i.e., a base coat of elastomeric binder with
or without first particles).
[0170] In another embodiment, when a tackifier is employed it may
be a hydrocarbon resin. In one embodiment where hydrocarbon resins
are employed, they may be selected from resins such as those
prepared from petroleum based feedstocks (e.g., aliphatic (C5),
aromatic (C9), DCPD (dicyclopentadiene) resins, or mixtures of
these).
[0171] Elastomeric primers not only promote bonding to substrate
surfaces such as metals, but also provide for improved adhesion to
the base coat. In addition, such primers compensate for differences
in the coefficient of thermal expansion between the HP/OP coating
and the substrate.
[0172] In other embodiments, primers comprise polyurethane
polymers. Such polyurethane containing primers ("polyurethane
primers") demonstrate excellent bonding to many substrates
including metallic substrates. When employing a polyurethane
primer, it is possible to incorporate first particles into the
primer and/or the base coat (a base coat of elastomeric binder with
or without first particles) for texture development. Thus, in
addition to promoting adhesion, the primer can also serve to
develop texture with increased surface area for improved adhesion
of the base coat comprising an elastomeric binder, develop wear
resistance, and develop hydrophobicity/oleophobicity. The HP/OP
coatings applied over the elastomeric primers or two part
polyurethane primers described herein display essentially equal
resistance to the loss of hydrophobicity in Taber Abraser
wear/abrasion resistance tests (as measured by Taber Abraser
cycles) when abrasive (CS-10) and soft (CS-0) wheels are
employed.
5.0 COATING APPLICATION METHOD
[0173] The coatings described herein (including any underlying
primer) can be applied to surfaces using any means known in the art
including, but not limited to, brushing, painting, printing,
stamping, rolling, dipping, spin-coating, spraying, or
electrostatic spraying. In one embodiment, one or more of a primer,
base coat and/or top coat are applied by spraying. In another
embodiment, each of a primer (if present), base coat and top coat
are applied by spraying.
[0174] In one embodiment the first and second coating compositions
described herein are separately prepackaged in a delivery
system/apparatus for spray applications, such as aerosol canisters
(e.g., pre-pressurized aerosol cans). In such an embodiment, the
first component and second component can be packaged in separate
delivery systems/apparatus. A propellant is added to the
system/apparatus that serves to drive the components out of their
canisters for delivery. Propellants will typically be a gas at
25.degree. C. and 1 atmosphere, but may be in a different phase
(liquid) under pressure, such as in a pressurized aerosol delivery
system. The propellant may be a gas (e.g., air or nitrogen) or a
liquefiable gas having a vapor pressure sufficient to propel and
aerosolize the first and/or second components as they exit their
delivery system/apparatus). Some exemplary propellants include:
liquefied petroleum gases, ethers (e.g., dimethyl ether (DME) and
diethyl ether); C1-C4 saturated hydrocarbons (e.g., methane,
ethane, propane, n-butane, and isobutene); hydrofluorocarbons (HFC)
(e.g., 1,1,1,2-tetrafluoroethane (HFC-134a),
1,1,1,2,3,3,3,-heptafluoropropane (HFC-227HFC), difluoromethane
(HFC-32), 1,1,1-trifluoroethane (HFC-143a),
1,1,2,2-tetrafluoroethane (HFC-134), and 1,1-difluoroethane
(HFC-152a)), and mixtures comprising any two, three or more of the
foregoing. In another embodiment, the propellant is a blend of
n-butane and propane.
[0175] Generally, the surfaces will be rigid or semi-rigid, but the
surfaces can also be flexible, for example in the instance of
wires, tapes, rubberized materials, gaskets, and ribbons.
[0176] The coatings described herein can be applied to virtually
any substrate to provide HP/OP properties. The choice of coatings
and coating processes that will be used may be affected by the
compatibility of the substrate and its surface to the coating
process and the component of the coating compositions. Among the
considerations are the compatibility of the substrate and its
surface with any solvents that may be employed in the application
of the coatings and the ability of a desired coating to adhere to
the substrate's surface.
[0177] Coatings may take any desired shape or form, limited only by
the manner and patterns in which they can be applied. In some
embodiments, the coating will completely cover a surface. In other
embodiments the coating will cover only a portion of a surface,
such as one or more of a top, side or bottom of an object. In one
embodiment, a coating is applied as a line or strip on a
substantially flat or planar surface. In such an embodiment the
line or strip may form a spill-resistant border.
[0178] The shape, dimensions and placement of HP/OP coatings on
surfaces can be controlled by a variety of means including the use
of masks, which can control not only the portions of a surface that
will receive a coating, but also the portions of a surface that may
receive prior treatments such as the application of a primer layer
or cleaning by abrasion or solvents. For example, where
sandblasting or a chemical treatment is used to prepare a portion
of a surface for coating, a mask resistant to those treatments
would be selected (e.g., a mask such as a rigid or flexible
plastic, resin, or rubber/rubberized material). Masking may be
attached to the surface through the use of adhesives, which may be
applied to the mask agent, the surface, or both.
[0179] In another embodiment HP/OP coatings are applied to a
ribbon, tape or sheet that may then be applied to a substrate by
any suitable means including adhesive applied to the substrate, the
ribbon or tape, or both. Ribbons, tapes and sheets bearing a
superhydrophobic coating may be employed in a variety of
applications, including forming spill proof barriers on surfaces.
Ribbons, tapes, and sheets are generally formed of a substantially
flat (planar) flexible material where one side (the top) is made
hydrophobic or superhydrophobic. This includes metal sheets,
ribbons, and tapes such as aluminum tape or other tapes (e.g.,
metal adhesive tape, plastic adhesive tape, paper adhesive tape,
fiberglass adhesive tape), wherein one side is coated with an HP/OP
coating and adhesive is applied to the other side. Once such HP/OP
ribbons, tapes, and sheets are prepared, they can be applied to any
type of surface including metal, ceramic, glass, plastic, or wood
surfaces, for a variety of purposes.
[0180] In one embodiment, HP/OP coatings are applied to the surface
of an object by a method comprising:
[0181] (a) applying a first component to all or part of the surface
of an object; followed by
[0182] (b) applying a second component to all or the part of the
surface of said object to which said first component was
applied.
[0183] In another embodiment, HP/OP coatings are applied by a
coating method comprising:
[0184] (a) applying a first component of a two-component coating
composition to all or part of the surface of an object; followed
by
[0185] (b) applying a second component of the two-component coating
composition to all or the part of the surface of said object to
which said first component was applied.
[0186] In such an embodiment, the first component and second
component may be applied using one or more methods selected
independently from brushing, painting, printing, stamping, rolling,
dipping, spin-coating, or spraying. Such a process is at least a
two-step process, but may include additional steps, such as a
second application of the second component making it a three or
more step process.
[0187] In an embodiment, one or both of the first and second
components are applied to a surface by spraying in a method
comprising:
[0188] (a) spraying a first component of a two-component coating
composition (e.g., an elastomeric binder and first particles) on
all or part of the surface of an object; followed by
[0189] (b) spraying a second component of said two-component
coating composition (e.g., second particles and optionally a
solvent) on all or part of the surface of an object to which said
first component was applied. In one embodiment, the spraying may be
conducted using first, second, or both components packaged in
aerosol spray canisters.
[0190] In an embodiment of the above-described coating process, a
base coat of elastomeric polymer binder and first particles (e.g.,
EXPANCEL particles) is applied as the first component. Once the
base coat loses sufficient solvent so that it: does not run when a
second component is applied; is close to being dry to touch (e.g.,
is tacky); becomes dry to touch; or is dry, a second coating
component (e.g., second particles and an optional dispersant such
as acetone) is applied. The solvent in the dispersant helps attach
the functional second particles to the binder of the base coat.
Other than allowing any solvent used as a dispersant to evaporate
no additional curing cycle is needed.
[0191] The coating obtained is durable and delivers HP/OP behavior
and can be applied to a variety of substrates including metals,
ceramics, polymerics and fabrics and in a number of specific
applications as set forth below.
6.0 APPLICATIONS
[0192] The elastomeric coating described herein may be employed in
a variety of applications including, but not limited to, coatings
for all or part of: [0193] 1) electronic equipment and their
electronic components or subassemblies (e.g., circuit boards),
including, but not limited to: cell phones, laptop computers,
electronic tablets (e.g., iPads), cameras, video games, Global
Positioning System (GPS) devices, radios, MP3 and electronic music
players, watches, video equipment, security systems, satellite
dishes and other portable electronics; [0194] 2) shoes (e.g.,
athletic shoes, casual shoes, dress shoes) and apparel for medical
and recreational use; [0195] 3) toys such as toy vehicles (e.g.,
trucks, cars), bikes, scooters, playground equipment (e.g., swings,
slides, teeter-totters), water toys, and toys for use in bathtubs;
[0196] 4) cleaning products--toilet brushes, toilet plungers, mops,
dust mops and cloths; [0197] 5) furniture and cooking preparation
and serving surfaces including both indoor and outdoor furniture
(e.g., lawn/patio furniture and park furniture such as tables,
chairs and benches) or employed as spill resistant borders on
surfaces that are substantially horizontal. [0198] 6) pet products
(e.g., litter boxes, litter scoopers, drinking and food bowls,
collars, litter particles, animal beds); [0199] 7) farm tools and
home and garden tools including shovels, spades, and rakes; [0200]
8) outdoor and exercise equipment (e.g., skis, snow boards), balls,
in-line skates, roller skates); [0201] 9) appliances--portions or
entire refrigerator plates (e.g., spill proof borders), freezer
liners, parts in washing machines, dishwashers, dehumidifiers,
humidifiers, and dryers; [0202] 11) baby/toddler products (e.g.,
car seats, potty seats, bibs, silverware (made from plastics),
cups, plates and diapers (or parts thereof); [0203] 12) food and
beverage containers (e.g., bottles and containers for beverages,
water, food); [0204] 13) sports equipment including balls (e.g.,
baseballs, tennis balls, footballs, soccer balls), gloves,
backpacks, and tents; [0205] 14) bedding (sheets, mattresses,
pillows, blankets); [0206] 15) food processing equipment and
kitchen equipment including coatings and/or spill resistant borders
for counters, backsplashes, the walls behind counters where food is
prepared, and abattoirs (e.g., wall coatings and/or curtains used
to section off a slaughter floor); [0207] 16) superhydrophobic body
spray; [0208] 17) automotive parts (e.g., bumpers, internal plastic
parts, engine parts, structural parts, fender well (wheel well)
liners, and car seats, particularly for convertibles); [0209] 18)
protective equipment (e.g., helmets, pads, and uniforms); [0210]
19) building products (e.g., rain spouts, doors, counters
(polymer), flooring, ceilings, screens, and roofing); [0211] 20)
laboratory equipment (e.g., trays, storage bins, tools, petri
dishes, funnels, tubing and animal cages); [0212] 21) electrical
equipment (e.g., electrical housings, electrical wiring, motors,
switches, insulators, and circuit boards); [0213] 22)
communications equipment (e.g., satellite dishes, antennas, and
communications towers); [0214] 23) plastic and/or metal tubing and
piping (e.g., PVC piping, copper piping, plastic and steel piping);
[0215] 24) lavatory/bathroom equipment and fixtures (e.g., urinals,
toilets, toilet seats, air and/or heat hand drying equipment, potty
seat bowls, counters, sinks, and soap dispensers); [0216] 25)
medical products including: beds and bed parts, bed pans, tubing,
tubular products, catheters, stents, surgical tools and operating
room equipment (such as robotic surgical tools), operating room
equipment (e.g., tables, light fixtures), walls, floors, sinks,
imaging equipment/machinery, laboratory testing
equipment/machinery, and medical instruments (e.g., medical
instruments used in surgical and nonsurgical applications); [0217]
26) wound care products, spray-on bandages, regular bandages, and
body affecting products (e.g., skin and/or hair spray; and [0218]
27) aviation and boating equipment (e.g., airplane fuselage, wings
and instrumentation), and boat bottoms, decks, and other places
throughout a boat.
[0219] Use of the coating can be facilitated by providing the first
and second components for preparing the coatings described herein
in a form that permits facile application. In one embodiment the
first and/or second components are prepackaged in solvent or
propellant delivery systems such as aerosol canisters (e.g.,
aerosol cans).
7.0 COATING EVALUATION
[0220] Coatings prepared using the elastomeric binder first
component and second coating composition described herein can be
evaluated using one or more criteria including, but not limited to:
[0221] 1. transparency and appearance, which are evaluated both
quantitatively and qualitatively; [0222] 2. durability of the SH/OP
behavior (wear resistance of the coating) to an applied force
using: [0223] 2a. semi-quantitative glove rub test in which the
thumb of a latex rubber gloved hand is stroked by hand over the
surface of the coating that has been applied to a substantially
planar surface until the coating no longer shows superhydrophobic
behavior. This test is a proxy for the ability of the surface to be
handled and retain its HP/OP properties. During the test, the area
of the surface contacted with the rubber glove is approximately 25
mm.times.25 mm and the force applied approximately 300 g (or about
0.5 g/square mm). The end of superhydrophobic behavior is judged by
the failure of more than half of the water droplets applied
(typically 20) to the tested surface to run (roll) off when the
surface is inclined at 5 degrees from horizontal. FIG. 4 shows an
exemplary testing apparatus used to determine the end of SH/OP,
[0224] 2b. loss of superhydrophobic behavior can also be judged
after the surface is subject to the action of a cylindrical rubber
finger moved across the surface. The finger is rubbed across the
surface using a motorized American Association of Textile Chemists
and Colorists (AATCC) CM-5 Crockmeter fitted with a 14/20 white
rubber septum (outside diameter of 13 mm and inside diameter of 7
mm with a contact surface area of 94 mm.sup.2) to contact the
coating with a force of 9N (Ace Glass, Inc., Vineland, N.J.,
Catalog No. 9096-244). The end of superhydrophobic behavior is
judged by the failure of more than half of the water droplets
applied to the tested surface (typically 20 droplets) to run (roll)
off when the surface is inclined at 5 degrees from horizontal,
[0225] 2c. loss of superhydrophobic behavior when the samples are
subject to Taber Abraser testing using CS-10 (abrasive) and/or CS-0
(non-abrasive) wheels at the indicated loads and speeds to
determine the point at which the surfaces lose superhydrophobicity.
Unless indicated otherwise, a load of 1,000 g is employed. All
Taber tests were conducted at a speed of 95 rpm unless stated
otherwise. The end of superhydrophobic behavior is judged by the
failure of more than half of the water droplets applied to the
tested surface (typically 20) to run (roll) off when the surface is
inclined at 5 degrees from horizontal, [0226] 2d. time to the loss
of superhydrophobicity under a shower of water. Water is applied
from a showerhead placed 152.4 cm (60 inches) above a substantially
planar test surface inclined at 5 degrees from the horizontal, the
showerhead having 70 nozzles with a 1 mm diameter orifice arranged
in 5 spokes of 5 nozzles and 15 spokes of 3 nozzles about a central
point on the circular showerhead. The apparatus delivers a shower
of 6 liters of water per minute using about 137900 to about 310275
Pa (about 20 to about 45 psi) over an approximately circular area
of about 150 cm in diameter at the level of the test surface. The
time to loss of superhydrophobic behavior is determined to be the
period of time after which water droplets from the shower begin to
"stick" to the surface (no longer freely run off the surface) of a
sample placed in the shower; [0227] 3. coating thickness and/or
surface roughness, expressed as the average roughness (Ra) unless
stated otherwise. Surface roughness has been found to be an
indicator that positively correlates with abrasion resistance
(increasing abrasion resistance with increasing roughness); [0228]
4. the ability of coated surfaces to resist ice formation in
dynamic testing and the adherence of ice to surfaces; [0229] 5.
electrical properties including resistance and permittivity' [0230]
6. oleophobicity, using either the contact angle of light mineral
oil with the coating or by assessing the interaction of droplets of
various liquid hydrocarbons having different surface tensions
employed in the ATCC 118-1997 Oil Repellancy test with the coating
surface. For testing, a coating is applied to a 4.times.4 inch
substantially planar plate. After the plate has dried and cured it
is placed on a 5.+-.1 degree slope relative to the horizontal and
five droplets of a test hydrocarbon are applied beginning with
Kaydol.TM. (available from CBM Group of N.C. Inc., 1308 N. Ellis
Ave., Dunn N.C. 28334). When droplets stick to the coating or wet
the coating, the Score (Oil Repellency Grade Number) is assigned.
Thus, Kaydol.TM. droplets rolling off earns a value of 1 or
greater, 65:35 Kaydol.TM.: n-hexadecane droplets rolling off earns
a value of 2 or greater, and so on. All test are conducted at room
temperature.
TABLE-US-00009 [0230] Score (Oil Repellency Grade Number)
hydrocarbon 0 None (Fails Kaydol .TM.) 1 Kaydol .TM. (mineral oil)
2 65:35 Kaydol .TM.:n-hexadecane 3 n-hexadecane 4 n-tetradecane 6
ndodecane 6 n-decane 7 n-octane 8 n-heptane
[0231] The oleophobicity of first or second particles (e.g., fumed
silica treated with a silane, silazane, silanol, siloxane,
fluorinated versions thereof, etc.) can be tested in the same
manner. In such tests the first and/or second particles are applied
to a clean 4.times.4 inch aluminum plate by spraying a suspension
containing 2% particles 98% acetone by weight to form a coating of
particles that cover the aluminum plate. After the plate has dried,
the above-listed hydrocarbon liquids are tested on the particle
coatings in the same manner as they would be on an elastomeric
coating, and the particles scored in the same manner.
8.0 CERTAIN EMBODIMENTS
[0232] Embodiment 1, has is divided into two sub-embodiments, that
are recited below as embodiments 1.1. and 1.2. In embodiment 1.1
the second component comprises second particles and one or more
solvents, but does not require a fluoropolymer. In contrast, the
second component of sub-embodiment 1.2 requires not only second
particles, but also a fluorinated polyolefin and/or a
Fluoroethylene-Alkyl Vinyl Ether (FEVE) copolymer, and one or more
solvents. In subsequent embodiments, any reference to embodiment 1
refers to either embodiment 1.1 and/or 1.2.
Embodiment 1.1
[0233] A combination of components for forming a coating
comprising:
[0234] A) a first component which comprises: [0235] i) an
elastomeric binder comprising one or more styrenic block
copolymers, wherein said elastomeric binder comprises from about 1%
to about 30% of said one or more styrenic block copolymers by
weight (e.g., about 1% to about 5%, about 5% to about 10%, about
10% to about 15%, about 15% to about 25%, or about 25% to about 30%
of said one or more styrenic block copolymers); [0236] ii)
optionally, one or more independently selected first particles
having a size of about 30 microns to about 225 microns, wherein,
when said first particles are present, the first component
comprises from about 0.01% to about 5% of said first particles by
weight (e.g., about 0.01% to about 5%, about 0.03% to about 1%,
about 0.05% to about 0.15%, about 0.1% to about 2.5%, or about 0.2%
to about 5% of said first particles by weight); and [0237] iii) one
or more independently selected solvents; and
[0238] B) a second component which comprises: [0239] i) one or more
independently selected second particles having a size of about 1
nanometer to about 25 microns, wherein said second particles
comprise one or more independently selected alkyl, haloalkyl, or
perfluoroalkyl moieties bound, either directly or indirectly, to
said second particles; and [0240] ii) optionally, one or more
independently selected solvents, wherein when said one or more
solvents are present, said second particles may be present in a
weight percent range selected from (0.1-1, 1.0-2.0, 0.2-2.0,
0.5-1.5, 0.5-2.0, 0.75-2.5, 1.5-2.0, 1.5-2.5, 2.0-3.0, 2.0-3.5, or
2.5-3.5) based on the weight of the one or more solvents and second
particles.
Embodiment 1.2
[0241] A combination of components for forming a coating
comprising:
[0242] A) a first component which comprises: [0243] i) an
elastomeric binder comprising one or more styrenic block
copolymers, wherein said elastomeric binder comprises from about 1%
to about 30% of said one or more styrenic block copolymers by
weight (e.g., about 1% to about 5%, about 5% to about 10%, about
10% to about 15%, about 15% to about 25%, or about 25% to about 30%
of said one or more styrenic block copolymers); [0244] ii)
optionally, one or more independently selected first particles
having a size of about 30 microns to about 225 microns, wherein,
when said first particles are present, the first component
comprises from about 0.01% to about 5% of said first particles by
weight (e.g., about 0.01% to about 5%, about 0.03% to about 1%,
about 0.05% to about 0.15%, about 0.1% to about 2.5%, or about 0.2%
to about 5% of said first particles by weight); and [0245] iii) one
or more independently selected solvents; and
[0246] B) a second component which comprises per 100 parts by
weight: [0247] i) 0.1 to 3.5 parts by weight (e.g., 0.1-1, 1.0-2.0,
0.2-2.0, 0.5-1.5, 0.5-2.0, 0.75-2.5, 1.5-2.0, 1.5-2.5, 2.0-3.0,
2.0-3.5, or 2.5-3.5) of one or more independently selected second
particles having a size of about 1 nanometer to about 25 microns,
wherein said second particles comprise one or more independently
selected alkyl, haloalkyl, or perfluoroalkyl moieties bound, either
directly or indirectly, to said second particles, or one or more
siloxanes or silazanes associated with said second particles;
[0248] ii) 0.1 to 1.0 parts by weight (e.g., 0.1-0.5, 0.5-1.0, or
0.3-0.7 parts) of a fluorinated polyolefin, (e.g., a polymer of
tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride,
such as Dyneon.TM. THV); [0249] and/or [0250] 0.06 to 0.6 parts by
weight (e.g., 0.06-0.0.1, 0.1-0.2, 0.2-0.4, or 0.4-0.6 parts) of a
Fluoroethylene-Alkyl Vinyl Ether (FEVE) copolymer, having an
average molecular weight of about 1,000 to 3,000 (e.g., about
1,000-2,000, 2,000-3,000, 1,500-2,500, or about 1,000, 1,500,
2,000, 2,500, or 3,000 Da); [0251] and [0252] iii) one or more
independently selected solvents for a the remainder of a total of
100 parts by weight. [0253] 2. The combination of embodiment 1,
wherein one or more of the styrenic block copolymers has a rubber
phase crosslinked to the polystyrene phase. [0254] 3. The
combination according to any of embodiments 1 to 2, wherein one or
more of the styrenic block copolymers has a rubber phase comprising
polybutadiene, polyisoprene, polyolefin or a mixture of any of
those rubber phase components (e.g., linear triblock copolymers of
styrene and ethylene/butylene with a polystyrene content of about
8% to about 36% by weight (e.g., about 8% to about 12%, about 12%
to about 18%, about 18% to about 24%, about 24% to about 30%, about
30% to about 36%, about 10% to about 20%, or about 8%, about 9%,
about 10%, about 11%, about 12%, about 13%, about 14%, about 15%,
about 17%, about 19%, about 20%, about 22%, about 24%, about 26%,
about 28%, about 30%, about 32%, about 34%, about 36%) or mixtures
of any two or more, three or more, or four or more of such triblock
copolymers, any one or more of which may optionally comprise 1% to
3% or 1.4% to 2.0% maleic anhydride). [0255] 4. The combination
according to any of embodiments 2 to 3, wherein said rubber
component comprises 60%-98%, 60%-70%, 70%-80%, 60%-90%, 80%-90%,
83%-93%, 85%-95%, or 89%-98%, of the elastomer by weight (based on
the dry weight of the elastomer present in the first component not
including any contribution by the first particles or other
materials present in that component). [0256] 5. The combination
according to any of embodiments 1 to 4, wherein said first
component further comprises one or more colorants, UV stabilizers,
antioxidants, rheological agents, and/or fillers. [0257] 6. The
combination according to any of embodiments 1 to 5, wherein said
first component further comprises up to 30% by weight of one or
more tackifiers (e.g., 1%-5%, 2%-8%, 5%-10%, 10%-15%, 15%-20%,
20%-25%, or 25%-30%). [0258] 7. The combination of embodiment 6,
wherein said one or more styrenic block copolymers and said one or
more tackifiers together comprise up to about 30% by weight of said
first component (e.g., up to about 10, 15, 20, 25, or 30%). [0259]
8. The combination according to any of embodiments 1 to 7, wherein
said elastomeric binder comprises one, two, three, or more triblock
copolymers. [0260] 9. The combination according to any of
embodiments 1 to 8, wherein said elastomeric binder comprises one
or more styrenic block copolymers of styrene and ethylene/butylene
with a polystyrene content of about 8% to about 36% by weight
(e.g., about 8% to about 14%, about 12% to about 20%, about 18% to
about 28%, about 22% to about 32%, about 26% to about 36%, about
8%, about 9%, about 10%, about 11%, about 12%, about 13%, about
14%, about 16%, about 18%, about 19%, about 20%, about 22%, about
24%, about 26%, about 28%, about 30%, about 32%, about 34%, about
36%), or mixtures of any two or more, three or more, or four or
more of such triblock copolymers. [0261] 10. The combination
according to any of embodiments 1 to 9, wherein one or more of said
styrenic block copolymers present in the elastomeric binder
comprise maleic anhydride (e.g., maleated copolymers having 1% to
3%, 1.4% to 2.0%, 1% to 1.4%, 1.6% to 3%, or 2% to 3% maleic
anhydride based on the weight of the copolymer). [0262] 11. The
combination according to any of embodiments 1 to 10, wherein at
least one, or at least two, of said one or more styrenic block
copolymers is a linear copolymer or a branched copolymer (e.g., a
dendrimer or arborol). [0263] 12. The combination according to any
of embodiments 1 to 11, wherein the elastomeric binder comprises a
first and a second maleated triblock copolymer of styrene and
ethylene/butylene wherein: [0264] said first maleated triblock
copolymer of styrene and ethylene/butylene has a polystyrene
content from about 8% to about 14%, with 0.4% to 1.6% (e.g., 0.5%
to 1.5%, 0.6% to 1.4%, or 0.7% to 1.3%) substitution (content by
weight) of maleic anhydride by weight of the first triblock
copolymer (and optionally less than 0.3% maleic anhydride free);
and [0265] said second maleated triblock copolymer of styrene and
ethylene/butylene has a polystyrene content of about 22% to about
32%, with 1.1% to 2.5% (e.g., 1.3% to 2.3% or 1.4% to 2.4%)
substitution of maleic anhydride by weight of the second triblock
copolymer. [0266] 13. The combination of embodiment 12, wherein
said first and/or second triblock copolymers are independently
selected linear or branched (e.g., arborols or dendrimers)
copolymers. [0267] 14. The combination according to any of
embodiments 12 to 13, wherein said first and second triblock
copolymers may be present in a weight ratio from about 4:1 to about
6.5:1 (e.g., the first copolymer to second copolymer ratio is:
about 4:1 to about 5.5:1; about 5:1 to about 6:1; or about 5.5:1 to
about 6.5:1). [0268] 15. The combination according to any of
embodiments 1-14, wherein said first particles are selected from
the group consisting of: glass, ceramic, rubber, plastic,
thermoplastic, wood, cellulose, metal oxides, silicon dioxide,
silicates, tectosilicates, germanium dioxide, plastic particles,
carbide particles, nitride particles, boride particles (e.g.,
zirconium or titanium boride), spinel particles, diamond particles,
fly ash particles, fibers and hollow glass spheres, hollow glass
particles or hollow plastic particles (e.g., glass, polymer,
plastic or thermoplastic particles, spheres, or microspheres),
wherein said first particles optionally comprise a colorant (e.g.,
colored or pigmented glass particles, plastic particles, rubber
particles, hollow glass or hollow plastic particles). [0269] 16.
The combination according to any of embodiments 1 to 15, wherein
said first particles comprise hollow glass or plastic particles
(e.g., glass, polymer, plastic or thermoplastic particles or
microspheres), and wherein said first particles optionally comprise
a colorant. [0270] 17. The combination according to embodiment 16,
wherein said hollow glass or hollow plastic particles have a size
(average diameter) in a range selected from the group consisting of
5 to 50 microns, 6 to 45 microns, 5 to 20 microns, 20 to 35
microns, and 35 to 50 microns. [0271] 18. The combination according
to any of embodiments 15 to 17, wherein said hollow plastic
particles have a density selected from the group consisting of less
than 60 kg/m.sup.3, less than 50 kg/m.sup.3, less than 40
kg/m.sup.3, less than 30 kg/m.sup.3, or less than 25 kg/m.sup.3,
and wherein said hollow glass particles have a density selected
from the group consisting of less than 125 kg/m.sup.3, less than
150 kg/m.sup.3, less than 200 kg/m.sup.3, less than 250 kg/m.sup.3,
less than 300 kg/m.sup.3, less than 350 kg/m.sup.3, less than 400
kg/m.sup.3, less than 450 kg/m.sup.3, less than 500 kg/m.sup.3,
less than 550 kg/m.sup.3, less than 600 kg/m.sup.3, or 600
kg/m.sup.3. [0272] 19. The combination according to any of
embodiments 1 to 18, wherein the second particles have an average
size in a range selected from the group consisting of from: about 1
nm to about 100 nm; about 10 nm to about 200 nm; about 20 nm to
about 400 nm; about 10 nm to 500 nm; about 40 nm to about 800 nm;
about 100 nm to about 1 micron; about 200 nm to about 1.5 microns;
about 500 nm to about 2 microns; about 500 nm to about 2.5 microns;
about 1 micron to about 10 microns; about 2 microns to about 20
microns; about 2.5 microns to about 25 microns; about 500 nm to
about 25 microns; about 400 nm to about 20 microns; and about 100
nm to about 15 microns. [0273] 20. The combination according to any
of embodiments 1 to 19, wherein said second particles comprise a
metal oxide, an oxide of a metalloid (e.g., silica), a silicate, or
a glass. [0274] 21. The combination according to any of embodiments
1 to 20, wherein said second particles are comprised of silica and
have an average size in a range selected from: about 1 nm to about
50 nm; about 1 nm to about 100 nm; about 1 nm to about 400 nm;
about 1 nm to about 500 nm; about 2 nm to about 120 nm; about 5 nm
to about 150 nm; about 5 nm to about 400 nm; about 10 nm to about
300 nm; or about 20 nm to 400 nm. [0275] 22. The combination
according to any of embodiments 1 to 21, wherein said second
particles have an average size in the range of from 1 nm to 100 nm
or from 2 nm to 200 nm. [0276] 23. The combination according to any
of embodiments 1 to 22, wherein said second particles comprise one
or more hydrophobic and/or oleophobic moieties. [0277] 24. The
combination according to any of embodiments 1 to 23, wherein said
second particles comprise one or more alkyl, fluoroalkyl, and/or
perfluoroalkyl moieties that are covalently bound to the second
particles directly, or bound indirectly through one or more atoms
bound to the second particles. [0278] 25. The combination according
to any of embodiments 1 to 24, wherein said one or more hydrophobic
or oleophobic moieties result from contacting the second particles
with one or more silanizing agents of formula (I):
[0278] R.sub.4-nSi--X.sub.n (I)
[0279] where n is an integer from 1 to 3; [0280] each R is
independently selected from [0281] (i) alkyl or cycloalkyl group
optionally substituted with one or more fluorine atoms, [0282] (ii)
C.sub.1 to 20 alkyl optionally substituted with one or more
substituents independently selected from fluorine atoms and C.sub.6
to 14 aryl groups, which aryl groups are optionally substituted
with one or more independently selected halo, C.sub.1 to 10 alkyl,
C.sub.1 to 10 haloalkyl, C.sub.1 to 10 alkoxy, or C.sub.1 to 10
haloalkoxy substituents, [0283] (iii) C.sub.2 to 8 or C.sub.6 to 20
alkyl ether optionally substituted with one or more substituents
independently selected from fluorine and C.sub.6 to 14 aryl groups,
which aryl groups are optionally substituted with one or more
independently selected halo, C.sub.1 to 10 alkyl, C.sub.1 to 10
haloalkyl, C.sub.1 to 10 alkoxy, or C.sub.1 to 10 haloalkoxy
substituents, [0284] (iv) C.sub.6 to 14 aryl, optionally
substituted with one or more substituents independently selected
from halo or alkoxy, and haloalkoxy substituents, [0285] (v)
C.sub.4 to 20 alkenyl or C.sub.4 to 20 alkynyl, optionally
substituted with one or more substituents independently selected
from halo, alkoxy, or haloalkoxy, and [0286] (vi)
--Z--((CF.sub.2).sub.q(CF.sub.3)).sub.r, wherein Z is a C.sub.1 to
12 or a C.sub.2 to 8 divalent alkane radical or a C.sub.2 to 12
divalent alkene or alkyne radical, q is an integer from 1 to 12,
and r is an integer from 1 to 4; [0287] each X is independently
selected from --H, --Cl, --I, --Br, --OH, --OR.sup.2, --NHR.sup.3,
or --N(R.sup.3).sub.2 group; [0288] each R.sup.2 is an
independently selected C.sub.1 to 4 alkyl or haloalkyl group; and
[0289] each R.sup.3 is an independently selected H, C.sub.1 to 4
alkyl, or haloalkyl group. [0290] 26. The combination according to
embodiment 25, wherein each R is selected independently from:
[0291] (a) an alkyl or fluoroalkyl group having from 6 to 20 carbon
atoms; [0292] (b) an alkyl or fluoroalkyl group having from 8 to 20
carbon atoms; [0293] (c) an alkyl or fluoroalkyl group having from
10 to 20 carbon atoms; [0294] (d) an alkyl or fluoroalkyl group
having from 6 to 20 carbon atoms when n is 2 or 3; [0295] (e) an
alkyl or fluoroalkyl group having from 8 to 20 carbon atoms when n
is 2 or 3; and [0296] (f) an alkyl or fluoroalkyl group having from
10 to 20 carbon atoms when n is 2 or 3. [0297] 27. The combination
according to any of embodiments 25 to 26, wherein R is
--Z--((CF.sub.2).sub.q(CF.sub.3)).sub.r, wherein Z is a C.sub.1 to
12 divalent alkane radical or a C.sub.2 to 12 divalent alkene or
alkyne radical, q is an integer from 1 to 12, and r is an integer
from 1 to 4. [0298] 28. The combination according to any of
embodiments 25 to 27, wherein n is 1, 2, or 3. [0299] 29. The
combination according to any of embodiments 25 to 28, wherein all
halogen atoms present in any one or more R groups are fluorine
atoms. [0300] 30. The combination according to any of embodiments
25 to 29, wherein each X is independently selected from --H, --Cl,
--OR.sub.2, --NHR.sup.3, and --N(R.sup.3).sub.2. [0301] 31. The
combination according to any of embodiments 25 to 30, wherein each
X is independently selected from --Cl, --OR.sub.2, --NHR.sup.3, and
--N(R.sup.3).sub.2. [0302] 32. The combination according to any of
embodiments 25 to 31, wherein each X is independently selected from
--Cl, --NHR.sup.3, and --N(R.sup.3).sub.2. [0303] 33. The
combination according to any of embodiments 1 to 32, wherein two,
three, four, or more than four compounds of formula (I) are
employed alone or in combination to modify at least one second
particle; or wherein said second particles incorporated into said
second component have an Oil Repellancy Grade Number greater than
or equal to about 1, 2, 3, 4, 5, 6, 7, or 8 when measured as a
coating applied to a metal plate in the absence of a binder. [0304]
34. The combination according to any of embodiments 1 to 33,
wherein said second particles are treated with a silanizing agent
selected from the group consisting of:
tridecafluoro-1,1,2,2-tetrahydrooctyl)silane;
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane;
(tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane;
(tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane;
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethyl(dimethylamino)silane;
(heptadecafluoro-1,1,2,2-tetrahydrodecyl)tris(dimethylamino)silane;
n-octadecyltrimethoxysilane; n-octyltriethoxysilane; and
nonafluorohexyldimethyl(dimethylamino)silane. [0305] 35. The
combination according to any of embodiments 1 to 34, wherein said
second particles are treated with a silanizing agent selected from
the group consisting of dimethyldichlorosilane,
hexamethyldisilazane, octyltrimethoxysilane, polydimethylsiloxane,
and (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane. [0306]
36. The combination according to any of embodiments 1 to 35,
wherein said first component and/or said second component further
comprise an independently selected solvent and/or propellant.
[0307] 37. The combination of embodiment 36, wherein said solvent
is an organic solvent or a mixture of two or more organic solvents,
and wherein either said organic solvent or said mixture of two or
more organic solvents comprises less than 10%, 5%, 2%, or 1% of
water by weight. [0308] 38. The combination of embodiment 36 or 37,
wherein said solvent or propellant comprises greater than 1%,
greater than 2%, greater than 5%, up to 10%, up to 20%, or greater
than 20% by weight of any one, two, three or more of each of air,
nitrogen, an inert gas, an alkane, a ketone, an ether, a
halogenated alkane, a halogenated alkene, an aromatic hydrocarbon,
an alcohol, methane, ethane, propane, butane, pentane, hexane,
heptane, ethylene, propene, acetone, methyl isobutyl ketone (MIKB),
methyl ethyl ketone (MEK), dimethylether (DME), diethylether,
methyl ethyl ether, methyl tert-butyl ether, chloromethane,
dichloromethane, carbontetrachloride, trichlorofluoromethane,
dichlorodifluoromethane, methanol, ethanol, propanol, butanol,
benzene, toluene, xylene, 1-chloro-4-(trifluoromethyl)-benzene,
carbon disulfide, and isomers of any of the foregoing, based upon
the total weight of solvent or propellant present in the
composition. [0309] 39. The combination according to any of
embodiments 1 to 38, wherein either the first component and/or
second component further comprise a colorant or pigment. [0310] 40.
The combination according to any of embodiments 1 to 39, wherein
said elastomeric binder has an ultimate strength greater than about
20, 21, 22, 23, 24, 26, 28, 30, 32, or 34 Mega Pascals (MPa) (e.g.,
greater than about 2,500, 2,750, 2,800, 2,900, 3,000, 3,200, 3,500,
3,750, 4,000, 4,250, 4,500, 4,750, or 4,900 psi) according to ASTM
D412. [0311] 41. A method of forming a hydrophobic coating on a
portion of a surface comprising the following steps: [0312] (a)
applying a first component according to any of embodiments 1 to 40
to at least a portion of the surface, wherein the portion of the
surface has optionally been treated with a primer (e.g, an
elastomeric primer) on all or part of the surface to which said
first component is to be applied; and [0313] (b) applying a second
component according to any of embodiments 1 (i.e., 1.1 or 1.2) to
40 to all or a portion of the portion coated in step (a), [0314]
wherein said coating has either hydrophobic or superhydrophobic
properties, and optionally is also oleophobic or superoleophobic.
[0315] 42. The method of embodiment 41, wherein said steps of
applying said first component and applying said second component
are conducted by methods selected independently from painting,
printing, stamping, rolling, dipping, spin-coating, spraying, and
electrostatic spraying. [0316] 43. A coating prepared by the method
according to any of embodiments 41 to 42. [0317] 44. The coating of
embodiment 43, wherein said coating is superhydrophobic and/or
superoleophobic. [0318] 45. The coating according to any of
embodiments 43 to 44, wherein said coating has an ultimate strength
greater than about 20, 21, 22, 23, 24, or 26 mega Pascals (MPa)
(e.g., greater than about 2,500, 2,750, 2,800, 2,900, 3,000, 3,200,
3,500, or 3,750 psi) according to ASTM D412. [0319] 46. The coating
according to any of embodiments 43 to 45, wherein said coating has
a modulus at 100% elongation of greater than 10, 11, 12, or 13 mega
Pascals (MPa) (e.g., greater than about 1,700, about 1,750, about
1,800, or about 1,850 psi) according to ASTM D412. [0320] 47. The
coating according to any of embodiments 43 to 46, having an
elongation at break of greater than about 100%, 110%, 120%, 140%,
160%, 180%, 200%, 250%, 300%, 350%, 400%, or 420%. [0321] 48. The
coating according to any of embodiments 43 to 47, having a relative
electrical permittivity at 100 MHz from about 0.2 to about 4 at
about 22.degree. C. (e.g., a relative electrical permittivity from
about 0.2 to about 1, from about 1 to about 2, from about 2 to
about 3, or from about 3 to about 4) as measured by ASTM D150 using
a 0.11 mm thick film. [0322] 49. The coating according to any of
embodiments 43 to 48, having a Total Luminous Transmittance of
about 75% to about 85% and a haze of about 85% to about 90% as
measure by ASTM D1003-11 on a film about 25 microns thick. [0323]
50. The coating according to any of embodiments 43-49, wherein said
coating is superhydrophobic and retains its superhydrophobicity
after being subjected to greater than 20, 25, 30, 40, 50, 60, 70,
80, 90, or 100 cycles on a Taber Abraser using CS-0 or CS-10 wheels
and a 250 gram load at 95 rpm at room temperature, wherein the end
of superhydrophobicity is determined to be the point when more than
half of the water droplets applied to the portion of the surface
subject to the action of the wheels do not roll off the surface
when the surface is inclined at a 5 degree angle at room
temperature. [0324] 51. The coating according to embodiment 50,
wherein said coating retains its superhydrophobicity after being
subjected to greater than 20, 25, 30, 40, 50, 60, 70, 80, 90, or
100 cycles on a Taber Abraser using CS-0 or CS-10 wheels and a
1,000 gram load at 95 rpm at 20.degree. C.-25.degree. C., wherein
the end of superhydrophobicity is determined to be the point when
more than half of the water droplets applied to the portion of the
surface subject to the action of the wheels do not roll off the
surface when the surface is inclined at a 5 degree angle at room
temperature. [0325] 52. The coating according to any of embodiments
43 to 51, wherein said coating is superhydrophobic and when said
coating is applied to a planar surface, it continues to display
superhydrophobic behavior after being subjected to a continuous
shower test of about six liters of water per minute at about
20.degree. C.-25.degree. C. for greater than 0.3, 0.5, 0.6, 1, 2,
3, or 3.5 hours, wherein the duration of superhydrophobic behavior
is determined to be the time when more than half of the water
droplets applied to a portion of the surface subject to said shower
do not roll off the surface when it is inclined at a 5 degree angle
at room temperature, [0326] wherein the shower test is conducted
using a showerhead with 70 nozzles with a 1 mm diameter orifice
arranged in 5 spokes of 5 nozzles and 15 spokes of 3 nozzles about
a central point on a circular showerhead, and wherein the
showerhead delivers approximately 6 liters of potable tap water per
minute using about 137900 Pa (Pascals) to 310275 Pa (20-45 psi
cycle over 5 minutes), and wherein the coating placed about 1.5
meters below the showerhead. [0327] 53. The coating of embodiment
52, wherein, when said coating is subjected to said continuous
shower test for a period of time sufficient to lose
superhydrophobic behavior, the coating regains superhydrophobic
behavior following drying at 20.degree. C. to 25.degree. C. and one
atmosphere of pressure, said shower testing and drying collectively
comprising a single test cycle. [0328] 54. The coating of
embodiment 53, wherein said coating regains superhydrophobic
behavior following more than 5, 10, 15, 20, 30, 40, 50, 75, 100,
150, or 200 of said test cycles. [0329] 55. A method according to
embodiment 41 or 42, wherein applying according to step (b) is
repeated to at least a portion of the coated surface if that
portion of the coated surface loses said hydrophobic,
superhydrophobic, oleophobic and/or superoleophobic properties, and
wherein following the repetition of step (b), the coated portion
regains hydrophobic, superhydrophobic, oleophobic and/or
superoleophobic properties. [0330] 56. A method according to
embodiment 41 or 42, wherein both steps (a) and (b) are repeated on
at least a portion of the coated surface if that portion of the
coated surface loses said hydrophobic, superhydrophobic, oleophobic
and/or superoleophobic properties, and wherein following the
repetition of steps (a) and (b), the coated portion regains
hydrophobic, superhydrophobic, oleophobic and/or superoleophobic
properties. [0331] 57. A coated surface, or a portion thereof,
resulting from the process of embodiment 55 or 56. [0332] 58. A
product comprising an aerosol spray container (e.g., a metal
canister) containing a first component according to any of
embodiments 1 to 40 and a propellant. [0333] 59. The product of
embodiment 58, wherein the aerosol spray container comprises a
valve assembly, a dip tube, and an actuator. [0334] 60. A product
comprising an aerosol spray container (e.g., a metal canister)
containing a second component according to any of embodiments 1 to
40 and a propellant. [0335] 61. The product of embodiment 60,
wherein the aerosol spray container comprises a valve assembly, a
dip tube, and an actuator. [0336] 62. A product comprising an
aerosol spray container according to embodiment 58 or 59, and a
second aerosol spray container according to embodiment 60 or
61.
9.0 EXAMPLES
Example 1
An HP/OP Elastomeric Coating
[0337] One part by weight of elastomeric coating (24% by weight of
solids) supplied as clear liquid from PLASTI DIP International,
Inc. (Blaine, Minn.) is combined with two parts by weight of xylene
and mixed. The mixture of elastomer and xylene is divided into six
aliquots and the indicated amounts of EXPANCEL 461 DET d25 (0.01%
to 0.5% by weight based on the total weight of the elastomer and
xylene mixture) is added to separate aliquots. The aliquots are
mixed to form first component compositions. The first component
compositions are sprayed onto individual aluminum plates to form a
base coat. The base coated aluminum plates are then top coated with
a second component consisting of a 2% (w/w) dispersion in acetone
of fumed silica particles modified to render them hydrophobic by
reacting them with tridecafluoro tetrahydroctyl trichloro silane
(fumed silica to silane ration is 2:1 by weight). Test data for
plates is summarized in the table below and the data is plotted in
FIG. 5. Coatings formed from PLASTI DIP elastomer have a tensile
strength of 3,740 psi (ASTM D-638), salt spray resistance greater
than 1,000 hours (ASTM B-117) and elongation at break of 430% (ASTM
D-638) without added first or second particles.
Data on HP/OP Elastomeric Coatings from Example 1
TABLE-US-00010 Approximate Taber Abraser EXPANCEL Glove Cycles to
loss of SH behavior Shower wt % Rubs CS-0 wheel CS-10 wheel ( )
(hr)* 0.01% 100 22 (13) 0.03% 325 72 (43) 1 0.06% 700 156 (93) 2
0.10% 750 167 (100) 3.5 0.30% 500 111 (67) 3.5 0.50% 400 89 (53)
3.5 Taber cycles estimated based upon a value of 4.5 glove rubs per
Taber cycle using CS-0 wheels and 7.5 glove rubs per Taber cycle
(sample rotation) using CS-10 wheels. The number in parentheses is
for the CS-10 data estimate. Taber load was 250 g. *Shower test was
terminated at 3.5 hours.
[0338] Data in the table above and FIG. 5 show that the abrasion
resistance (glove rub performance and estimated Taber cycles)
reaches a maximum when about 0.1% of EXPANCEL particles are
incorporated into the base coat. Shower time to loss of
superhydrophobicity also increases with increasing amounts of
EXPANCEL particles incorporated in the base coat. Shower time to
loss of superhydrophobic behavior saturates beyond 0.1%
addition.
Example 2
[0339] Six first component mixtures are prepared as in Example 1
using 0.1% of five different types of EXPANCEL particles (duplicate
samples containing EXPANCEL 031 DU 400), and the first components
are each applied to a different aluminum plate by spraying to form
a base coat. The base coating on each plate is then top coated with
a second component comprising a 2% (w/w) dispersion of fumed silica
particles treated with tridecafluoro tetrahydroctyl trichlorosilane
suspended in acetone. For samples containing EXPANCEL 031 DU 400)
the aluminum plates were heated to 80.degree. C. for 2-3 minutes
either before or after the application of the second component to
expand the EXPANCEL particles. Test data for the plates are
summarized in the table of performance data, below, and plotted in
FIG. 6.
[0340] Performance Data by Using 0.1% by Weight of Different
EXPANCEL Particles in Elastomeric Coating
TABLE-US-00011 EXPANCEL Glove Taber Abraser Cycles to Shower type
Rubs loss of SH behavior (hr) 461 DET d25 800 178 (106) 4 461 DE 40
d25 500 111 (67) 2.5 461 DET 40 d25 650 144 (87) 4 920 DE 80 d30
400 89 (53) 2.5 031 DU 40 75 17 (10) 0.5 (heated before top
coating) 031 DU 40 75 17 (10) 0.5 (heated after top coating) Taber
cycles estimated based upon a value of 4.5 glove rubs per Taber
cycle using a 250 g load, CS-0 wheels and 7.5 glove rubs per Taber
cycle (sample rotation) using CS-10 wheels. The number in
parentheses is for the CS-10 data estimate.
[0341] Data in the table above and FIG. 6 show that incorporation
of EXPANCEL 461 DET d25 and EXPANCEL 461 DET 40 d25 produces a
combination of resistance to the loss of HP/OP when being handled
("handleability" assessed by glove rubs and resistance to Taber
abrasion testing), and shower time to loss of superhydrophobicity.
Unexpanded EXPANCELs 031 DU 40 did not show good performance. The
shower times track closely and positively correlate with glove rubs
and Taber cycles (higher glove rubs correspond to higher shower
time).
Example 3
Scaled Preparation of Fumed Silica Second Particles
[0342] A series of aluminum plates primed with PLASTI DIP primer
for metals according to the manufacturer's instructions are base
coated as in Example 1, with 0.1% EXPANCEL 461 DET d25 particles
added to the first component, which is applied by spraying. After
the base coat has dried at room temperature, one set of plates is
treated with a second component as in Example 1. The second
component comprises 20 g of 20-80 nm fumed silica particles having
a surface area of about 200 m.sup.2/g (Evonik Industries, Horsham
Pa.), treated in an Osterizer kitchen blender for 10 minutes at
room temperature with 10 g of tridecafluoro tetrahydroctyl
trichloro silane. A second set of plates is also treated with a
second component as in Example 1, using silica from the same
supplier prepared in a larger batch using 5,000 g of the silica
reacted with tridecafluoro tetrahydroctyl trichloro silane 2,500 g
in a 10 kg reactor system at room temperature for 2-3 hours. In
this example, after top coats are applied the plates are dried for
15 minutes at 170.degree. F. (77.degree. C.). Two plates treated
with fumed silica prepared in the blender and two plates treated
with fumed silica prepared in the reactor are subjected to
thickness and surface roughness measurements. The point at which
the plates lose superhydrophobic behavior is also determined using
Taber Abraser equipped with CS-0 wheels at a 1,000 g load and using
glove rub testing. Loss of superhydrophobic behavior is deemed to
be the point at which more than half of the water droplets applied
to the tested portion of a substantially planar surface inclined at
5 degrees from the horizontal do not roll off the plate.
[0343] Data on plates coated with fumed silica particles prepared
in the blender is summarized in Table 7, and data on plates treated
with fumed silica prepared in the reactor is shown in Table 8.
TABLE-US-00012 TABLE 7 Blender Grade NPT 74 Coating Coating
Thickness Thickness (mils) Ra (mils) Ra Sample #1 Sample #1 Sample
#2 Sample #2 0.73 2.61 1.1 3.267 0.67 2.66 1.01 3.337 0.49 0.82
0.76 1.08 Avg 0.6625 2.635 1.0025 3.302 Glove Rubs 600 Taber
Abraser 50 cycles to loss of SH
TABLE-US-00013 TABLE 8 Reactor Grade NPT 74 Coating Coating
Thickness Thickness (mils) Ra (mils) Ra Sample #1 Sample #1 Sample
#2 Sample #2 0.92 3.246 1.07 3.027 1.35 3.259 0.94 2.35 0.88 0.86
1.01 0.88 Avg 1.04 3.2525 0.9375 2.6885 Glove Rubs 900 Taber
Abraser 30 cycles to loss of SH
The data in Tables 7 and 8 indicate that superhydrophobic coatings
prepared with fumed silicas produced in reactors on different
scales display similar properties.
Example 4
Transparency and Haze
[0344] Glass plates are coated with a near transparent coating
based on elastomeric binder systems as in Example 1 with the
exception that the plate marked P does not include first particles
(EXPANCEL particles) in the base coat (first component). The plate
marked SE-1 contains 0.1% of EXPANCEL particles in the first
component. Samples are tested for Haze value and Total Luminous
Transmittance (TLT) values using the method described in ASTM
D1003. The instrument is calibrated without a sample present using
air as a standard. Calibration values are TLT=100 and Haze=0.
Clear, clean, uncoated glass plates have average readings of
TLT=90.6 and a haze reading of 0.18. Plates lacking first particles
(P-coat) have about the same transparency as clear clean glass. The
presence of EXPANCEL particles in the base coat reduces the
transparency by about 10%. The coating haze increases from about
0.18 for glass to about 61% for coatings without first particles
and to about 90% for coatings including EXPANCEL particles in the
base coating. See Table 9.
TABLE-US-00014 TABLE 9 P-Coat Sample Average (no first particles)
Reading 1 Reading 2 Reading 3 Readings Transmittance 90.50 90.30
90.40 90.4 Haze 60.70 62.40 60.80 61.30 SE-1 Sample (first
particles included in the base coat) Transmittance 80.00 79.10
80.10 79.73 Haze 88.60 90.80 89.30 89.57
Example 5
Effect of Coating Thickness
[0345] Six aluminum plates (10 cm.times.10 cm) are primed with
PLASTI DIP primer for metal (product f938 hp). Pairs of the primed
plates are spray coated with first component as in Example 1 (0.1%
EXPANCELs) to achieve a base coat thicknesses of about 1, 1.5, or
2.6 ml respectively. One plate at each coating thickness is top
coated with 2 ml of the second component as described in Example 1,
and the second plate at each coating thickness is top coated with 4
ml of second component. Coating thicknesses, which include the
primer thickness, and Taber Abraser data are summarized in Table
10A and data is plotted in FIG. 7.
TABLE-US-00015 TABLE 10A Data summary for plates made with varying
coating thicknesses Volume of Passes of Final Tabers (CS-10)
Topcoat Base Thickness to end of super- Sample (mL) Coat (mil)
hydrophobicity Notes 1.1 2 1 0.55 35 some tearing 2.1 2 3 1.5 35 no
tearing 3.1 2 5 2.6 35 no tearing 1.2 4 1 0.9 45 some tearing 2.2 4
3 2.2 50 no tearing 3.2 4 5 2.9 50 no tearing
[0346] Based on the data above, 2 ml of top coat (0.02 ml/cm.sup.2)
produces no benefits in performance improvement at any thickness.
However, when the top coat is increased to 4 ml (0.04 ml/cm.sup.2),
it provides an adequate performance that increases with coating
thickness. While not wishing to be bound by any theory, it appears
that at the higher application rate the top coat penetrates to some
depth into the base coat. When only 2 ml (0.02 ml/cm.sup.2) is
applied the coating may be sufficient to just cover the base coat,
but not enough to permit the second particles to penetrate at any
significant level that will increase the durability of SH
performance. In addition, when the base coat is very thin, tearing
becomes the failure mode.
Example 6
Effect of Priming with Polyurethane Primer
[0347] Aluminum plates are primed with a two-part polyurethane
coating (DESMOPHEN 670BA with DESMODUR N75 BA-XBMS, Bayer Material
Science) prepared and applied per manufacturer's instructions. An
elastomeric coating as described in Example 1 (0.1% of EXPANCEL 461
DET d25) is employed in the first component. Coated plates are
measured for coating thickness (including primer thickness) and
their ability to resist the loss of superhydrophobic behavior using
a Taber Abraser fitted with CS-10 (abrasive) wheels and CS-0 (soft
rubber) wheels at a 1,000 g load is recorded. All end points for
loss for superhydrophobic behavior are measured for water droplet
roll off with the plates inclined at 5 degrees from the horizontal
(5 degree tilt angle). Test data is summarized in Table 10B.
TABLE-US-00016 TABLE 10B Summary of data on Al plates primed with
two-part polyurethane as primer Sample 1 2 3 Total Coating Total
Coating Total Coating and Primer and Primer and Primer
Thickness(mils) Thickness (mils) Thickness (mils) 3.25 3.13 4.7
3.13 3.06 4.9 3 3.1 4.16 3.32 3.45 4.24 4.15 4.01 4.47 Avg
Thickness 3.37 3.35 4.494 CS-10 Wheel CS-0 Wheel Glove Rubs Tabers
CS-10 40 Tabers CS-0 40 Glove Rubs >1000
Example 7
Nearly Transparent HP/OP Elastomeric Coating with Various First
Particles
[0348] Elastomeric coatings are prepared on aluminum test plates as
described in Example 1, with the exception that the first component
contains first particles as indicated in Table 11. The test plates
are assessed for loss of superhydrophobic behavior using glove rubs
as a rapid test for assessment of handleability and abrasion
resistance/durability. Test data for all coated plates are
summarized in Table 11.
TABLE-US-00017 TABLE 11 Summary of data for non near transparent
elastomeric binder system based coatings Taber Abraser Particle
Amount Glove Predicted Particle Particle Size weight Rubs cycles
with Designation Type (micron) (%) (#s) CS-0 wheel* EXPANCEL
Thermoplastic 10-40 0.01 100 22 DET Encapsulated with gas EXPANCEL
Thermoplastic 10-40 0.1 750 167 DET Encapsulated with gas EXPANCEL
Thermoplastic 10-40 0.5 400 89 DET Encapsulated with gas Hollow
Glass Hollow glass 25-90 0.5 800 178 Spheres spheres K25 Hollow
Glass Hollow glass 15-70 0.5 >400 >89 Spheres spheres K46
*Projected based on GR/CS-0 = 4.5
[0349] Thermoplastic particles and hollow glass particles yield
similar performance in increasing coating durability.
Example 8
Non-Transparent Elastomeric Coatings Prepared with Micronized
Rubber First Particles
[0350] PLASTI DIP (24% solids by weight) elastomeric coating (5
parts by weight of the liquid as provided by the supplier) is
combined with seven parts by weight of xylene and mixed. To the
resulting mixture of elastomer and xylene, micronized rubber
particles (Lehigh Technology, Tucker, Ga.) about 4% or about 7.7%
by weight are added to separate aliquots (based on the weight of
the elastomer and xylene combined). The particles are mixed into
each aliquot to form first component compositions. The first
component compositions are applied to separate aluminum plates to
form base coats, and the base coats are top coated with a second
component as described in Example 1.
[0351] Test data showing resistance to the loss of
superhydrophobicity based on glove rub testing and Taber testing
for the coatings incorporating rubber particles is provided in
Table 12. That data shows the incorporation of elastomeric binder
used in this example with micronized rubber particles produces
highly durable surfaces that show increasing resistance to the loss
of hydrophobicity with increasing amounts of rubber first particles
incorporated into the binder up to at least 7.69%.
TABLE-US-00018 TABLE 12 Summary of data on non near transparent
elastomeric binder based coatings Taber Glove Abraser Particle
Particle Particle Amount Rubs cycles Designation Type Size (.mu.m)
weight (%) (#s) with CS-0* Micronized Ground 70 4 1450 191 Rubber
Rubber particles Micronized Ground 70 7.69 1800 237 Rubber Rubber
particles *Projected based on GR/CS-0 wheel ratio of 7.6 for a 250
g load at 95 rpm.
Example 9
Non-Transparent Elastomeric Coating with Micronized Rubber
Particles with and without Primer
[0352] Elastomeric coatings are prepared as in Example 8 employing
7.69% of micronized rubber by weight in the first component. The
coatings are applied to clean but unprimed aluminum plates or
aluminum plates that have been treated with an elastomeric metal
primer (PLASTI DIP metal primer) per the manufacturer's
instructions. All plates are substantially planar. The top coating
step is the same as in Example 8 and Example 1. The coated plates
are assessed for resistance to the loss of SH behavior using a
Taber Abraser fitted with CS-0 wheels or CS-10 wheels (as
indicated) using 1,000 g loads at 95 rpm, resistance to the loss of
SH behavior using glove rubs, and coating thickness, which is
measured including primer where present. The appearance of coating
failures is also recorded for each plate and the data set forth in
Table 13.
TABLE-US-00019 TABLE 13 Observations from Taber Abraser Testing of
Plates With and Without Primer Coating Thickness (mil) Comments
Coating Without Primer without primer Taber CS-0 6 cycles 1.5 Rips
and Tears Taber CS-10 10 cycles 1.5 Rips and Tears Glove Rubs 1200
1.5 No Rips or Tears With primer Coating With Elastomeric Primer
with elastomeric primer Taber CS-0 50 cycles 1.75 No Rips or Tears
Taber CS-10 40 cycles 1.65 No Rips or Tears Glove Rubs 1600 1.75 No
Rips or Tears
[0353] The data indicates that samples with and without primer
resist the loss of superhydrophobicity with a very large number of
glove rubs. Taber Abraser testing results in a loss of that
property due to ripping and/or tearing of the coating in the
absence of primer. Loss of superhydrophobic behavior is assessed
using the above-described droplet run off test with plates inclined
at 5 degrees from the horizontal. Priming of the metal surfaces
increases the number of Taber cycles the test samples can withstand
without losing superhydrophobic behavior by about 4 to about 8
fold, regardless of whether non-abrasive rubber (CS-0) or abrasive
(CS-10) wheels are employed.
Example 10
Thermal Stability of Elastomeric Coatings
[0354] Elastomeric coatings incorporating EXPANCELs as in Example
1, or micronized rubber as in Example 8, are scraped from their
plates and used for thermogravimetric analysis (TGA). TGA data for
the coatings is plotted in FIGS. 10 and 11, respectively. Details
of the test conditions are listed inside each of the graphs. Data
from these charts show the following:
[0355] 1. The coating containing EXPANCEL is stable up to
241.degree. C. (465.degree. F.)
[0356] 2. The coating containing micronized rubber is stable up to
261.degree. C. (502.degree. F.)
Based upon the data presented above the coatings may be used up to
temperatures of 200.degree. C. or 400.degree. F.
Example 11
HP/OP Coatings Employing Varying Proportions of a Styrenic Block
Copolymer and Tackifier
[0357] Three styrenic block copolymers (SBCs), FG 1901, FG 1924 and
RP 6670, each obtained from KRATON.RTM., are dissolved in xylene at
20% by weight. Regalrez.TM. 1094 tackifier, obtained from Eastman
Chemical Company, is dissolved in xylene at 20% by weight. Varying
ratios of SBCs and tackifier solutions are mixed and UV stabilizers
and antioxidants, 0.1% Irganox.RTM. 1520L, 0.056% Tinuvin.RTM. 328,
and 0.056% Tinuvin.RTM. 770DF (% by weight), are added.
[0358] Each of the mixtures of SBCs and tackifier formed is used as
a first component and HP/OP coatings are prepared as in Example 1,
using 0.1% EXPANCEL particles as first particles. The HP/OP
coatings were tested for durability using a Taber Abraser equipped
with CS-10 wheels and a 1,000 g load. The results are shown in
Table 14.
TABLE-US-00020 TABLE 14 FG 1901/Regalrez 1094 FG 1924/Regalrez 1094
RP 6670/Regalrez 1094 Glove Taber Glove Taber Glove Taber Ratio
Rubs cycles Ratio Rubs cycles Ratio Rubs cycles 43/57 300 35 25/75
300 30 25/75 500 30 50/50 400 40 50/50 750 35 33/66 500 40 57/43
550 45 66/33* 800 20 50/50 750 45 66/33 1000 60 66/33 1500 50
75/25* 350 35 75/25* 1000 50 90/10* 600 25 100/0* 600 25 *Taber
testing induced tearing.
Example 12
HP/OP Coatings Employing Maleated Styrene-Ethylene/Butylene-Styrene
(SEBS) Block Copolymers
[0359] Coatings were prepared using first components comprising
maleated SBCs (e.g., maleated SEBS block copolymers)
TABLE-US-00021 TABLE 15 Total Component Exemplary Composition Base
Coat Parts by Weight Components Component (Total of 100 parts) (By
weight where given) Maleated SBC 7 to 9 One or more maleated
Styrene- Ethylene/Butylene-Styrene (SEBS) Block Copolymers (e.g.,
Kraton FG 1901, FG 1924 and/or RP 6670.diamond-solid.) Tackifier
3.5 to 7 Nonpolar hydrogenated hydrocarbon resin (e.g., produced by
polymerization and hydrogenation of monomeric hydrocarbons) or
esterified hydrogenated rosin. e.g., Eastman Regalrez .TM. 1094 or
Foral .TM. 105E Antioxidant(s) 0.05 to 0.2 Antioxidant(s) (e.g.,
phenolic or hindered phenolic antioxidants e.g., Irganox 1520L
First Particles 0.05 to 20 Expancel 461 DET 40 d25 (0.05-0.2%)
SoftSand 5-15% Glass bubbles (e.g., K1, S22, or A16/500) 1%-10% UV
stabilizer(s) 0.05 to 0.5 e.g., Tinuvin .RTM. 328 and/or 770DF
Solvent Bring to 100 parts xylene (or mixed xylenes), acetone,
n-hexane (or total including all mixed hexanes),
1-chloro-4-(trifluoromethyl)- other components benzene or mixtures
thereof Top Coat Component Parts by weight Source Reactor Grade
0.05 to 6.0 (e.g., 2%) Ross Technology -- see Example 3 NPT 74
Solvent Bring to 100 parts by xylene (including mixed xylenes or
technical weight total including grade), acetone, n-hexane (or
mixed hexanes), 1- all other components
chloro-4-(trifluoromethyl)-benzene or mixtures thereof
.diamond-solid.RP 6670 is a maleated form of KRATON series A
polymers, which are hydrogenated block copolymers having styrene
copolymerized with ethylene/butylene in the midblock (S-(EB/S)-S).
Styrenic block copolymers (SBCs FG 1901, FG 1924 and RP 6670, each
obtained from KRATON .RTM.), tackifier (Regalrez .TM. 1094 or FORAL
.TM. 105E obtained from Eastman Chemical Company), UV stabilizers
(e.g., Tinuvin .RTM. 328 and/or 770DF from BASF), antioxidants
(e.g., Irganox .RTM. 1520L) and first particles are
dissolved/suspended in solvent using solvent to adjust the total
components by weight to 100 parts.
[0360] The HP/OP coatings were tested for durability using a Taber
Abraser equipped with CS-10 wheels and a 1,000 g load. The results
are shown in Table 14.
* * * * *