U.S. patent application number 11/897978 was filed with the patent office on 2008-09-11 for coating compositions for producing transparent super-hydrophobic surfaces.
Invention is credited to Richard J. Baumgart, Subbareddy Kanagasabapathy, Frances E. Lockwood, Wen-Chen Su.
Application Number | 20080221263 11/897978 |
Document ID | / |
Family ID | 40130372 |
Filed Date | 2008-09-11 |
United States Patent
Application |
20080221263 |
Kind Code |
A1 |
Kanagasabapathy; Subbareddy ;
et al. |
September 11, 2008 |
Coating compositions for producing transparent super-hydrophobic
surfaces
Abstract
A coating composition and process for generating transparent,
near-transparent, and semi-transparent super-hydrophobic coatings
on surfaces having a contact angle of greater than 165 degrees. The
composition comprises hydrophobic nanoparticles of silsesquioxanes
containing adhesion promoter groups and low surface energy
groups.
Inventors: |
Kanagasabapathy; Subbareddy;
(Lexington, KY) ; Baumgart; Richard J.; (Paris,
KY) ; Su; Wen-Chen; (Lexington, KY) ;
Lockwood; Frances E.; (Georgetown, KY) |
Correspondence
Address: |
WOOD, HERRON & EVANS, LLP
2700 CAREW TOWER, 441 VINE STREET
CINCINNATI
OH
45202
US
|
Family ID: |
40130372 |
Appl. No.: |
11/897978 |
Filed: |
August 31, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60841720 |
Aug 31, 2006 |
|
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60931545 |
May 24, 2007 |
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Current U.S.
Class: |
524/588 |
Current CPC
Class: |
C09D 183/04 20130101;
C08K 3/36 20130101; C09D 5/1618 20130101; C08K 9/04 20130101; Y10T
428/2995 20150115; C09D 7/62 20180101; C09D 7/67 20180101; Y10T
428/31663 20150401 |
Class at
Publication: |
524/588 |
International
Class: |
C08L 83/04 20060101
C08L083/04 |
Claims
1. A transparent hydrophobic coating composition comprising: a) at
least one R.sub.1 group containing a component comprising an alkyl,
aryl groups bonded directly to an Si atom of the silsesquioxanes
structure, said alkyl groups are preferably with carbon atom
C.sub.1 to C.sub.20; R.sub.2 groups containing a component
comprising a substituted alkyl group; and a substituted group
comprising an adhesion promoter; and a substitute group comprising
a cross linking group; b) a solvent: and c) an adhesive
promoter.
2. The transparent hydrophobic coating composition of claim 1, said
alkyl groups including an additional moiety bonded there to
selected from the group consisting of a hydroxyl group, a CF.sub.3,
and a perfluoro group.
3. The transparent hydrophobic coating composition of claim 1,
wherein said aryl group substitutes phenyl and benzyl groups.
4. The transparent hydrophobic coating composition of claim 1,
wherein said cross linking group is selected from the group
consisting of a hydroxyl, an amino, and an epoxy group.
5. The transparent hydrophobic coating composition of claim 1,
wherein said polysiloxane comprises a polysilsesquioxane having
repeating units of the formula.
6. A hydrophobic self-cleaning coating composition for forming a
dirt repellant film on a clear, translucent, or painted metal,
glass, or polymer substrate, comprising an effective amount of
nanoparticles of a treated fumed silica in an acetone in solution
imparting a degree of hydrophobicity to a coated surface providing
a wetting surface having a contact angle of at least 165 degrees as
compared to water having a contact angle of from 80 to 90 degrees
on a noncoated surface and said composition imparting a degree of
hydrophobicity to a coated surface providing a wetting surface
having a tilt angle of sliding of less than 2 degrees as compared
to water having a tilt angle of sliding of 90 degrees on a
noncoated surface; said transparent hydrophobic coating composition
comprising: a) at least one R.sub.1 group containing a component
comprising an alkyl, aryl groups bonded directly to an Si atom of
the silsesquioxanes structure, said alkyl groups are preferably
with carbon atom C.sub.1 to C.sub.20; R.sub.2 groups containing a
component comprising a substituted alkyl group; and a substituted
group comprising an adhesion promoter; and a substitute group
comprising a cross linking group; b) a solvent: and c) An adhesive
promoter.
7. The composition of claim 1, wherein said composition is clear
upon application to a treated surface.
8. The composition of claim 1, wherein said composition is
translucent upon application to a treated surface.
9. The composition of claim 1, including an aerosol.
10. The composition of claim 9, wherein said composition is
dispersed in an aerosol propellant containing a solvent selected
from the group consisting of an alcohol, a hydrocarbon, mineral
spirits, and water.
11. The composition of claim 10, wherein said aerosol propellant is
selected from the group consisting of a carbon dioxide, a
hydrocarbon, a fluorocarbon, and compressed air.
12. The composition of claim 11 wherein said hydrocarbon, comprises
a propane/isobutane.
13. The composition of claim 1, including a binding agent applied
to said substrate, prior to application of said hydrophobic
self-cleaning coating composition.
14. The composition of claim 13, wherein said binding agent
comprises a binding agent pretreatment solution containing a zinc
oxide.
15. The composition of claim 14, wherein said binding agent
comprises about 0.05% by weight of said binding agent pretreatment
solution.
16. The composition of claim 1, wherein said nanoparticles are from
about 7 to about 600 nanometers.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Application Ser. No. 60/841,720 filed on Aug. 31, 2006 and U.S.
Provisional Application Ser. No. 60/931,545 filed on May 24, 2007
and U.S. application Ser. No. 11/699,883 filed on Jan. 30, 2007
which claims priority from U.S. Provisional Application Ser. No.
60/763,294 filed on Jan. 30, 2006 all of which are incorporated by
reference herein in their entirety. Reference to documents made in
the specification is intended to result in such patents or
literature cited are expressly incorporated herein by reference,
including any patents or other literature references cited within
such documents as if fully set forth in this specification.
TECHNICAL FIELD
[0002] The technical field of this invention is producing super
hydrophobic coatings on surfaces.
BACKGROUND OF THE INVENTION
[0003] The invention relates to protection of various surfaces from
contaminants and from oxidation of surfaces in air and moisture.
One of the primary applications includes the use of this technology
in vehicle appearance products. Although, products for similar
applications are widely available on the market, these products
often require rinsing with water after use and usually rely on a
temporary hydrophilic surface. Typically when the water dries from
the surface, water marks, smears or spots are left behind due to
the deposits of minerals which were present as dissolved solids in
water. This problem is apparent when cleaning glass, painted
surfaces, steel, alloy, plastic or ceramic surfaces. A means of
solving this problem known in the literature is to dry the water
from the surface using a cloth or chamois before the water marks
form. However, this drying process is time consuming and requires
considerable physical efforts.
DESCRIPTION OF THE PRIOR ART
[0004] There are several published articles which address the
elimination of water marks. In one example, U.S. Pat. No.
5,759,980, a composition, comprises a surfactant package consisting
of a silicone-based surfactant and a polymer which is capable of
bonding to a surface to make a hydrophilic film which eliminates
the problem of water marks. However, this hydrophilic coating may
tend to be removed from the surface by a single water rinse. German
publication DE-A21 61 591 also describes a composition for cleaning
cars wherein the surface is again made hydrophilic by using amino
functional polymers. This coating also tends to be rinsed off from
a single rinse. In another example, PCT WO97/48927 teaches a direct
method of a cleaning composition, method of application and
apparatus. This reference describes using a spray gun comprising
separate chambers for the cleaning solution and ion exchange resin.
Moreover, it recommends to use purified rinse water which is
expensive to use. There are number of waxes and other products
available in the market for attempting to retain this spot free
finish. Typically these products are designed to hydrophobically
modify the surfaces after waxing so that the water will bead up on
the hydrophobic surface. However, the hydrophobicity of the
surfaces is not sufficient enough to bead the water completely from
the surface thereby leaving the water spot when the water
dries.
[0005] Therefore, there is a need to develop a process and coating
for protecting various surfaces from the appearance of water marks,
corrosion, and dirt repellency, while maintaining the water
repellency even after several water rinses.
SUMMARY OF THE INVENTION
[0006] The present invention provides a coating composition and
process for generating transparent, near-transparent, and
semi-transparent super-hydrophobic coatings on surfaces having a
contact angle of greater than 165 degrees. One preferred
composition comprises hydrophobic nanoparticles of silsesquioxanes
containing adhesion promoter groups and low surface energy groups
such as materials that contain fluoroalkyl groups, which reduce the
surface energy due to its small atomic radius and high
electronegativiity forming a stable covalent bond with carbon.
[0007] The silsesquioxane based composition provides a coating
composition for generating transparent super-hydrophobic surfaces,
comprising silsesquioxanes with I) an adhesion promoter, ii) low
surface energy groups and to a process for producing such surfaces.
The coating utilizes hydrophobic nanoparticles of silsesquioxanes
in a solvent.
[0008] The super hydrophobic coating composition that can be used
to make wet and dry dirt repellent surfaces to keep the surfaces
clean for a reasonable period of time. The coating may utilize
hydrophobic nanoparticles of silsesquioxanes in a solvent with an
adhesion promoter. More particularly, the particle may be silicon
based including, for example, silica, silicates and
polysilsesquioxane. A nanocomposite structure may be formed by
casting, depositing or forming the material including nanocomposite
particles.
[0009] The coating solves the problem of poor resistance to UV
light and/or abrasion found in previous coatings of similar nature.
The transparent, near transparent, or semi-transparent coatings can
be produced using the current invention whereas previous coatings
of comparable hydrophobicity have all been white or opaque. The
coating can be applied by a single and easy spraying method and the
super hydrophobic property can be achieved by drying the film at
room temperature for 5 to 10 minutes. A preferred coating has good
resistance to UV light and some resistance to abrasion.
[0010] The present invention relates to a process and composition
for creating super hydrophobic coatings (contact angle >165
degree) on various surfaces, preferably plastics, woods, metals,
glass, ceramics, and painted and/or waxed surfaces. Super
hydrophobic coatings of this type have recently been cited for the
purpose of keeping surfaces cleaner, similar to the lotus plant,
and the high contact angle is known as the "lotus effect"".
Examples of commercially available materials which attempt to
produce this "Lotus" cleaning effect are products sold under the
trade name of MINCOR available from BASF, and TEGTOP available from
Degussa. These products, have been tested for their ability to
protect various surfaces from the appearance of water marks,
corrosion, and dirt repellancy and while maintaining the water
repellency, but were deemed unsuitable. When coated alone or mixed
with various types of hydrophobic particles, these and many other
polymers, e.g. acrylic resins, silicon containing graft copolymers,
homopolymers, methyl methcyrlate, copolymers of acrylic monomers,
styrene monomers, styrene copolymers, functional/non functional
siloxanes, inorganic hybrids such as silsesquioxanes, acrylic
polymers containing perfluoro pendant groups, TEFLON/nafion type
fluoro polymers, urethanes, fluorourethanes, polyethers, polyesters
and silicon modified polyacrylates, it was found that the resulting
coating is initially super hydrophobic and may remain so for long
periods indoors; however, when exposed to outdoor UV light, rubbed
even slightly, or in general exposed to weather, the coating loses
superhydrophobicity (which we define as the instant shedding of
water with no remaining drops) becomes less hydrophobic within days
or even hydrophilic and hence less useful for the object of the
present invention. Examination under the microscope after a week of
exposure on a panel in a UV cabinet reveals that a coating made
from fumed silica and at least one film forming binder as taught in
U.S. Pat. No. 6,683,126 disintegrates over time. Furthermore it has
been published in a General Motors reference, (GM reference), that
lotus type coatings, when exposed to steam, lose their
hydrophobicity. No practical lotus coatings exist for the object of
this invention.
[0011] The invention described herein provides a long lasting super
hydrophobic coating that has the benefit of self cleaning of
various surfaces and will reduce icing caused by water drops.
However it should be noted that snow will cover horizontal surfaces
but can be more easily removed from the surfaces protected with the
coating formed from the composition of the present invention.
Furthermore, the coatings of the instant invention are inexpensive
compared to paint and can be sprayed regularly if necessary to keep
the surface clean without any further steps.
[0012] The static contact angle of a drop of liquid can be used to
measure the wettability of surfaces. The static contact angle can
be defined as the angle enclosed by the surface and a tangent along
the surface of the liquid drop in the region of the contact point
of the liquid drop with the surface. The contact angle is measured
through the liquid drop. A contact angle of 0 defines complete
wettability and does not form a drop. A contact angle of 180
degrees defines complete unwettability.
[0013] The hydrophobic self-cleaning coating composition forms a
dirt repellant film on a clear, translucent, or painted metal,
wood, glass, or polymer substrate, comprising an effective amount
of a silsesquioxanes in a solvent and combined with an adhesion
promoter imparts a degree of hydrophobicity at ambient temperature
to a coated surface providing a wetting surface having a contact
angle of at least 165 degrees as compared to water having a contact
angle of from 80 to 90 degrees on a noncoated surface and said
composition imparting a degree of hydrophobicity to a coated
surface providing a wetting surface having a tilt angle of sliding
of less than 2 degrees as compared to water having a tilt angle of
sliding of 90 degrees on a noncoated surface.
[0014] In one preferred embodiment, the hydrophobic self-cleaning
coating composition forms a temporary dirt repellant film or
coating on a clear, translucent, or painted metal, wood, glass, or
polymer substrate, comprising an effective amount of a degree of
hydrophobicity to a coated surface providing a wetting surface
having a contact angle of at least 165 degrees as compared to water
having a contact angle of from 80 to 90 degrees on a noncoated
surface and said composition imparting a degree of hydrophobicity
to a coated surface providing a wetting surface having a tilt angle
of sliding of less than 2 degrees as compared to water having a
tilt angle of sliding of 90 degrees on a noncoated surface.
[0015] The preferred embodiment utilizes organopolysiloxanes having
an atomic ratio of oxygen to silicon of 1.5 are generally called
polysilsesquioxanes. Polysilsesquioxanes have a ladder-like
structure as shown in FIG. 1, wherein R is the same or different
and is lower alkyl, phenyl, substituted phenyl, phenethyl and
methylphenethyl, with at least one of the groups represented by R
being lower alkyl, and n is an integer.
[0016] It is an object of the present invention to provide a super
hydrophobic coating, which is so hydrophobic that water will bounce
off the surface of nominally horizontal coated plates. In this case
the contact angle is so large (greater than 165 degree) that it can
not be measured by conventional instrumentation.
[0017] Another object of the present invention is to provide
coatings that are practical in use, that do not degrade rapidly in
sunlight, that can be readily applied, and have enough resistance
to abrasion to survive for a practical length of time, at least
between vehicle washes, and preferably for weeks or months
depending upon environmental conditions to which the coating is
exposed.
[0018] Another object of the present invention is to provide a
process for applying such coatings.
[0019] Another object of the present invention is to use "lotus"
coatings for a different purpose, to reduce drag.
[0020] In the instant invention, compositions are provided having a
small amount of nanoparticles of silsesquioxanes with an adhesion
promoter or other hydrophobic nanoparticle component with good UV
light stability and good adhesion to metals, wood, glass, plastic,
painted and many other surfaces. The composition does not comprise
any binding materials as taught in the prior art. The nanoparticle
containing compositions can be sprayed in a broad range of solid
mixtures using VOC complaint solvents with aerosol propellants. The
final uniform coating is obtained by drying the film at room
temperature for 5 to 10 minutes.
[0021] Although a variety of nanoparticles will work if coated with
a hydrophobic material, e.g. silsesquioxanes, perfluoroacrylic
resins etc. only a few polymers serve as an adequate base for the
particles because the surface area of exposed polymer is vastly
increased due to very thin film and rough surface area produced by
the coating. This problem was either not understood or not solved
in the prior art references. Formulation of the coating to resist
abrasion and the elements, particularly UV light is an object of
this invention. UV stability of the super hydrophobic coatings is
extremely important especially for exterior surfaces which are
exposed to UV light.
[0022] Selection of the nanoparticle enables the formulation of a
composition without any binder which will produce a practical lotus
effect that is not easily destroyed by fog, UV light, or abrasion,
e.g. by flowing water.
[0023] Other objects, features, and advantages of the invention
will be apparent with the following detailed description taken in
conjunction with the accompanying drawings showing a preferred
embodiment of the invention and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] A better understanding of the present invention will be had
upon reference to the following description in conjunction with the
accompanying drawings in which like numerals refer to like parts
throughout the several views and wherein:
[0025] FIG. 1 shows the chemical structure for a silsesquioxane.;
and
[0026] FIG. 2 shows the typical contact angle of coated and
uncoated area of a panel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] The present invention provides a coating composition which
is super hydrophobic, and when applied on a surface, typically
metal, fiberglass, plastic, ceramic, wood, glass, painted material,
etc. produces a difficult to wet surface. Contact angles of a
liquid such as water on the coated surface should be difficult to
measure with conventional means because the water droplet bounces
or runs off the surface when applied. The contact angle exceeds 165
degrees and the tilt angle of sliding is less than 2 degrees.
[0028] The coatings in the examples are optimized formulations that
contain super hydrophobic nanoparticles, for example, a
silsesquioxane with an adhesion promoter. Although a variety of
nanoparticles will work if coated with a hydrophobic material, e.g.
fumed silica and/or titania, perfluoroacrylic resins etc. only few
polymers serve as an adequate base for the particles because the
surface area of exposed polymer is vastly increased due to very
thin film and rough surface area produced by the coating.
[0029] The present invention provides a formulation which can
utilize nanoparticles in the composition without any binder to
produce a practical lotus effect that is not easily destroyed by
fog, UV light, or abrasion, or by flowing water.
[0030] This transparent, uniform film is stable when exposed
outdoors to strong UV light, rain, wind, etc. for a minimum time of
one month, compared to 3 days for most other polymers including
acrylates, urethane acrylates, homopolymers and copolymers of
ethylenically unsaturated monomers, acrylic acid/maleic anhydride
copolymers etc. Stability is determined by observing that the super
hydrophobic effect has not diminished and by examining the film
under the microscope before and after exposure.
[0031] The substituted polysiloxane materials used in this
invention include those with organic groups having from one to
seven carbon atoms such that the substituted polysiloxanes have
lower alkyls that provide an average of 0.3 to 1.5, preferably 0.5
to 1.3, carbon atoms per silicon atom. Aqueous dispersions of lower
alkyl substituted polysiloxanes of this invention can be prepared
by hydrolysis of the corresponding alkyl substituted silanes by
conventional methods.
[0032] In at least some preferred embodiments the substituted
polysiloxane material is a polysilsesquioxane. Useful
silsesquioxanes include (a) compounds having repeating units of the
formula (RSiO[3/2]) where R is a substituent comprising a single
alkyl or aryl group or mixtures of alkyl or aryl groups of carbon
atoms, and/or (b) condensates of hydrolsylates of the formula
R[x]Si(OR')[y] where x+y is 4 and x is from 0 to 2 and y is from 2
to 4; R is a single alkyl or aryl group or mixture of alkyl or aryl
groups comprising up to 7 carbon atoms, optionally substituted with
halogen atoms, mercapto groups, and/or epoxy groups; and R' is an
alkyl radical with 1 to 4 carbon atoms.
[0033] Useful silsesquioxanes are described in U.S. Pat. Nos.
3,493,424, 4,351,736 and 4,781,844, each incorporated herein by
reference in its entirety. The silsesquioxane materials can be any
of the types described in U.S. Pat. No. 4,781,844 (Kortmann, et
al), U.S. Pat. No. 4,351,736 (Steinberger et al.), U.S. Pat. No.
5,073,442 (Knowlton et al.) or U.S. Pat. No. 3,493,424 (Mohrlok et
al.) each of which are incorporated herein by reference in its
entirety.
[0034] As set forth in U.S. Pat. No. 6,723,438, the silsesquioxanes
may be prepared by adding silanes to a mixture of water, a buffer,
a surface active agent and optionally an organic solvent, while
agitating the mixture under acidic or basic conditions. It is
preferable to add the quantity of silane uniformly and slowly in
order to achieve particles having an average size in the range of
300 to 1500 Angstroms. The exact amount of silane that can be added
depends on the substituent R and whether an anionic, non-ionic, or
cationic surface active agent is used. Examples of preferred
surfactants include long chain alkyl ether sulfates which do not
impart significant coloration. Some surfactants have been observed
to result in yellowing of the resultant coating.
[0035] More particularly, as best illustrated in FIG. 1, the
preferred embodiment is shown where R.sub.1 groups containing a
component comprising an alkyl, aryl groups bonded directly to an Si
atom of the silsesquioxane structure. The alkyl groups are
preferably with carbon atom C.sub.1 to C20 and up to C30, which may
or may not having an additional moiety bonded thereto. The
additional moiety is preferably hydroxyl group, CF.sub.3, perfluoro
groups. Aryl groups substitute phenyl and benzyl groups. R.sub.2
groups containing a component comprising substituted alkyl group.
The substituted groups are adhesion promoter and cross linking
groups such as hydroxyl, amino, epoxy groups.
[0036] The following silanes are useful in preparing the
polysiloxanes of the present invention: methyltrimethoxysilane,
methyltriethoxysilane, methyltriisopropoxyoxysilane,
ethyltrimethoxysilane, ethyltriethoxysilane,
propyltrimethoxysilane, isobutyltrimethoxysilane,
isobutyltriethoxysilane, 2-ethylbutyltriethoxysilane,
tetraethoxysilane, mercaptopropyltrimethoxysilane, and
2-ethylbutoxytriethoxysilane fluoroalkylriethaoxysilane, hexadecyl
troethoxysilane.
[0037] The nanoparticles composed of silsesquioxanes have a
particle size ranging from about 7 to 600 nanometers.
[0038] To make the hydrophobic silsesquioxane coating easier to
apply it can be dispersed in solvents, preferably alcohol, acetone
and or aliphatic hydrocarbons and/or other VOC complaint solvents
to make it sprayable.
[0039] The solvent may also be selected from the group consisting
of an alcohol, a hydrocarbon, mineral spirits, and water. A
preferred method of application is by diluting the solvent an
aerosol containing a propellant such as carbon dioxide, a
hydrocarbon (for example mixtures of propane isobutane), a
fluorocarbon, difloroethane, and compressed air. One preferred
hydrocarbon is a propane/isobutane.
[0040] A preferred embodiment of the present invention provides a
coating composition for generating transparent super-hydrophobic
surfaces, comprising silsesquioxanes with I) an adhesion promoter,
ii) low surface energy groups and to a process for producing such
surfaces. For example, one preferred adhesion promoter comprises a
urethane polymer.
[0041] The coating utilizes hydrophobic nanoparticles of
silsesquioxanes in a solvent. A transparent coating (Haziness
<1%) can be produced using the current silsesquioxane and
adhesion promoter composition whereas previous coatings of
comparable hydrophobicity have all been white or opaque. The
coating can be applied by a single and easy spraying method and the
super hydrophobic property can be achieved by drying the film at
room temperature for 5 to 10 minutes. A preferred coating has good
resistance to UV light and some resistance to abrasion.
[0042] Three (3) grams of silsesquioxane is dispersed in 97 grams
of alcohol and mixed for 5 min. 0.1 grams of an adhesion promoter,
for example, urethane polymer is added to the
silsesquioxanes/alcohol dispersion and mixed for about 5 min. The
whole mixture was sonicated for 5-50 seconds to generate uniform
particle size.
[0043] Preferred adhesion promoters include urethane, polyurethane,
acrylic polymers, siloxane, nitrogen containing materials,
polyamides, carboxylic containing groups, polyamides with nitrogen
groups and the like.
[0044] Other adhesion promoter groups applicable to the present
composition include copolymers of (meth)acrylic acid with
alkyl(meth)acrylates, alkenyl(meth)acrylates, aryl(meth)acrylates,
alkylaryl(meth)acrylates, (meth)acrylonitrile or the like;
terpolymers of (meth)acrylic acid with alkyl(meth)acrylates,
alkenyl(meth)acrylates, aryl(meth)acrylates,
alkylaryl(meth)acrylates, (meth)acrylonitrile, styrene and
optionally substituted styrenes, vinyl acetate or the like; tetra
or pentapolymers of (meth)acrylic acid with alkyl(meth)acrylates,
alkenyl(meth)acrylates, aryl(meth)acrylates,
alkylaryl(meth)acrylates, (meth)acrylonitrile, styrene and
optionally substituted styrenes, vinyl acetate or the like;
copolymers of vinylacetic acid with alkyl(meth)acrylates and/or
alkenyl(meth)acrylates; products of esterification of polymers
containing hydroxyl groups with anhydrides of di- or polycarboxylic
acids such as copolymers of hydroxyalkyl(meth)acrylates with
(meth)acrylic acid, alkyl(meth)acrylates, alkenyl(meth)acrylates,
aryl(meth)acrylates, alkylaryl(meth)acrylates, (meth)acrylonitrile,
styrene and optionally substituted styrenes, vinyl acetate or the
like; and products of esterification of polymers containing
hydroxyl groups with acid chlorides such as copolymers of
hydroxyalkyl(meth)acrylates with (meth)acrylic acid,
alkyl(meth)acrylates, alkenyl(meth)acrylates, aryl(meth)acrylates,
alkylaryl(meth)acrylates, (meth)acrylonitrile, styrene and
optionally substituted styrenes, vinyl acetate or the like.
[0045] Other polymeric adhesion promoters which may be used are
polyalkyl(meth)acrylates in which the alkyl group is, for example,
methyl, ethyl, isopropyl, n-propyl, isobutyl, n-butyl, n-hexyl,
2-ethylhexyl, and the like, and binders are those which are
insoluble in water, soluble in organic solvents, and partially
soluble or swellable in aqueous alkaline solutions. Adhesion
promoters which contain hydroxyalkyl(meth)acrylates are very useful
when further esterified with anhydrides such as crotonic anhydride,
maleic anhydride, itaconic anhydride, and the like, and when
esterified with acid chlorides such as acryloyl chloride,
methacryloyl chloride, cinnamoyl chloride, and the like. The
polymers described above are particularly useful when the molecular
weight is between 1000 and 300,000, more preferred between 5,000
and 200,000 and most preferred between 10,000 and 120,000. It is
preferred that the acid number is between 5 and 300, more preferred
between 10 and 250 and most preferred between 25 and 175.
EXAMPLES
[0046] The following examples provide formulations of compositions
in accordance with the present invention and provide examples of
the range of ingredient percentages by weight providing an
effective amount of the particular ingredients deemed necessary to
obtain the desired results in single application.
[0047] One preferred formula for the wax composition of the present
invention is set forth in Example 1 as follows
Example 1
[0048] Synthesis of Silsesquioxanes A1: In a typical experiment, 3
g of 28% ammonium hydroxide was dissolved in 30 g of ethanol and
transferred into a 2 necked 100 ml round bottomed flask. The whole
mixture was heated to 75.degree. C. for 30 minutes under stirring.
After 30 minutes, a known amount of fluorinated triethoxysilane,
methyl triethoxysilane and tetraethylorthosilicate (TEOS) in the
ratio of May 5/50/45 respectively were added. Continued the
reaction for another 12 hrs at 75.degree. C. and cooled the
reaction.
Example 2
[0049] A2 In another experiment, the experimental procedure follows
the same as in example 1 except that the composition of the
monomers (fluorinated triethoxysilane, methyl triethoxysilane and
Tetraethylorthosilicate (TEOS)) were changed to 0/50/50.
Example 3
[0050] A3, In another experiment, the experimental procedure
follows the same as in example 1 except that the composition of the
monomers (fluorinated triethoxysilane, methyl triethoxysilane and
Tetraethylorthosilicate (TEOS)) were changed to Feb. 10/40/50.
Example 4
[0051] A4, In another experiment, the experimental procedure
follows the same as in example 1 except that the composition of the
monomers (fluorinated triethoxysilane, methyl triethoxysilane and
Tetraethylorthosilicate (TEOS)) were changed to Oct. 40, 1950.
Example 5
[0052] A5, In another experiment, the experimental procedure
follows the same as in example 1 except that the composition of the
monomers (fluorinated triethoxysilane, methyl triethoxysilane and
Tetraethylorthosilicate (TEOS)) were changed to 20/30/50.
Example 6
[0053] A6, In another experiment, the experimental procedure
follows the same as in example 1 except that the composition of the
monomers (fluorinated triethoxysilane, methyl triethoxysilane and
Tetraethylorthosilicate (TEOS)) were changed to 50/20/30.
Example 7
[0054] A7, In another experiment, the experimental procedure
follows the same as in example 1 except that the composition of the
monomers (fluorinated triethoxysilane, methyl triethoxysilane and
Tetraethylorthosilicate (TEOS)) were changed to 80/10/10.
[0055] The compositions and the monomers choice were not limited to
the monomers shown in examples. Any substituted trialkoxy silanes
shown in FIG. 1 can be utilized to synthesis silsesquioxanes.
Example 8
[0056] Coating Composition, B1: 0.5 g of A1 was dispersed in 10 g
of isopropyl alcohol and sonicated the whole mixture and applied to
a painted surface by aerosol coating method. The transparent, semi
permanent coating showed contact angle of 168 degree.
Example 9
[0057] B2: 0.5 g of A2 was dispersed in 10 g of isopropylalcohol
and sonicated the whole mixture and applied to a painted surface by
aerosol coating method. The semi permanent coating showed contact
angle of 157 degree, however the transparency was lost
completely.
Example 10
[0058] B3: 0.5 g of A3 was dispersed in 10 g of isopropylalcohol
and sonicated the whole mixture and applied to a painted surface by
aerosol coating method. The transparent, semi permanent coating
showed contact angle of 172 degree.
Example 11
[0059] B4: 0.5 g of A4 was dispersed in 10 g of isopropylalcohol
and sonicated the whole mixture and applied to a painted surface by
aerosol coating method. The transparent, semi permanent coating
showed contact angle of 168 degree.
[0060] The foregoing detailed description is given primarily for
clearness of understanding and no unnecessary limitations are to be
understood therefrom, for modification will become obvious to those
skilled in the art upon reading this disclosure and may be made
upon departing from the spirit of the invention and scope of the
appended claims. Accordingly, this invention is not intended to be
limited by the specific exemplifications presented herein above.
Rather, what is intended to be covered is within the spirit and
scope of the appended claims.
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