U.S. patent application number 13/199686 was filed with the patent office on 2012-01-05 for organometallic films, methods for applying organometallic films to substrates and substrates coated with such films.
This patent application is currently assigned to Aculon, Inc.. Invention is credited to Eric L. Hanson.
Application Number | 20120003481 13/199686 |
Document ID | / |
Family ID | 39321477 |
Filed Date | 2012-01-05 |
United States Patent
Application |
20120003481 |
Kind Code |
A1 |
Hanson; Eric L. |
January 5, 2012 |
Organometallic films, methods for applying organometallic films to
substrates and substrates coated with such films
Abstract
Organometallic coatings or films, substrates coated with such
films and methods for applying the films to the substrates are
disclosed. The organometallic film or coating is derived from a
transition metal compound containing both halide ligands and
alkoxide ligands. Coated articles comprising polymer substrates and
adhered to the substrate surface an organometallic film in which
the metal comprises halide and alkoxide ligands are also
disclosed.
Inventors: |
Hanson; Eric L.; (Carlsbad,
CA) |
Assignee: |
Aculon, Inc.
San Diego
CA
|
Family ID: |
39321477 |
Appl. No.: |
13/199686 |
Filed: |
September 7, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11985150 |
Nov 14, 2007 |
8048487 |
|
|
13199686 |
|
|
|
|
60859193 |
Nov 15, 2006 |
|
|
|
Current U.S.
Class: |
428/412 ;
428/413; 428/425.9; 428/447; 428/480; 428/522; 428/704 |
Current CPC
Class: |
B05D 1/185 20130101;
B82Y 40/00 20130101; Y10T 428/31511 20150401; Y10T 428/31504
20150401; Y10T 428/31786 20150401; Y10T 428/31609 20150401; Y10T
428/31935 20150401; Y10T 428/31678 20150401; Y10T 428/31507
20150401; Y10T 428/31649 20150401; B82Y 30/00 20130101; B05D 7/52
20130101; B05D 2201/00 20130101; Y10T 428/31663 20150401; Y10T
428/31699 20150401 |
Class at
Publication: |
428/412 ;
428/704; 428/425.9; 428/480; 428/413; 428/522; 428/447 |
International
Class: |
B32B 27/08 20060101
B32B027/08 |
Claims
1. A coated article comprising: a) a polymer substrate and adhered
to the substrate surface b) an organometallic film in which the
metal of the organometallic film comprises ligands selected from
halide and alkoxide.
2. The coated article of claim 1 in which the polymer is selected
from polycarbonate, polyurethane, polyester, polyepoxide, acrylic
polymers and copolymers and polysiloxanes.
3. The coated article of claim 1 in which the metal is selected
from Ti, Zr, La, Hf, Ta and W.
4. The coated article of claim 1 in which the organometallic film
also has unreacted hydroxide ligands.
5. The coated article of claim 1 in which a different film is
deposited on the organometallic film.
6. The coated article of claim 5 in which the different film is
derived from a composition that has groups that are reactive with
the alkoxide ligands of the organometallic film.
7. The coated article of claim 6 in which the composition is an
organophosphorus acid and is selected from a phosphoric acid, a
phosphonic acid, a phosphinic acid including derivatives
thereof.
8. The coated article of claim 7 in which the organophosphorus acid
or derivative thereof is a fluorinated material.
9. The coated article of claim 1 in which the coated article is
eyewear.
10. The coated article of claim 1 in which the article is an
electrooptical article.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent
application Ser. No. 11/985,150, filed Nov. 14, 2007, which claims
priority from U.S. Provisional Patent Application Ser. No.
60/859,193, filed Nov. 15, 2006.
FIELD OF THE INVENTION
[0002] The present invention relates to organometallic films, to
methods of applying such films to surfaces of various substrates
and to substrates coated with organometallic films.
BACKGROUND OF THE INVENTION
[0003] Self-assembled films or layers on various substrates are
well known in the art. These films or layers typically have
functional groups (head groups) that bond to a cofunctional group
on the substrate surface and organo groups that have some mutual
attraction to neighboring molecules in the layer(s) or to the
surface. The self-assembled films are used in various applications
such as for medical and electrical use. In medical applications,
the self-assembled films are used to form an interfacial layer
between a titanium orthopedic implant and the surrounding body
tissue. For electrical applications, the self-assembled films are
useful for improving the performance of devices that incorporate
organic-inorganic interfaces such as those found in organic
light-emitting diodes. An example of a self-assembled organic layer
is disclosed in U.S. Pat. No. 6,645,644 in which an organometallic
compound such as a titanium or zirconium transition metal alkoxide
is applied to a substrate such as a metal having a native oxide
surface. The alkoxide groups react with the oxide groups forming a
secure surface bond. The free or unreacted alkoxide groups are
available for reaction with reactive groups such as acid groups in
a subsequently applied layer.
[0004] Unfortunately, such organometallic coatings often have poor
durability and are easily removed from many substrates,
particularly polymer substrates such as polycarbonates and
polysiloxanes.
[0005] It would be desirable to provide an organometallic coating
derived from a transition metal alkoxide that has better durability
and adhesion to various substrates, particularly polymer
substrates.
SUMMARY OF THE INVENTION
[0006] The present invention provides a method of depositing an
organometallic coating to a substrate comprising: [0007] (a)
contacting the surface of the substrate with a transition metal
compound having both halide and alkoxide ligands so as to deposit a
film on the substrate, [0008] (b) exposing the film to conditions
sufficient to form a polymeric metal oxide film with alkoxide and
hydroxyl ligands.
[0009] The present invention also provides for organometallic films
or coatings comprising a polymeric transition metal oxide with
alkoxide, hydroxyl ligands and halide ligands.
[0010] The present invention also provides for coated polymer
substrates having adhered to the substrate surface an
organometallic film comprising ligands selected from halide and
alkoxide.
[0011] The organometallic film can act as an anchor for functional
coatings (e.g. hydrophobic, antifog, antistatic, conductive, etc.),
or as an adhesion promoter at organic/organic, organic/inorganic
interfaces (e.g. as an adhesion promoter at a polyimide/polyester
interface).
DETAILED DESCRIPTION
[0012] The organometallic compound used in the method of the
invention is preferably derived from a transition metal selected
from Group IIIB of the Periodic Table or a transition metal
selected from Group IVB, VB and VIB of the Periodic Table.
Preferred transition metals are titanium, zirconium, lanthanum,
hafnium, tantalum and tungsten. The organo portion of the
organometallic compound contains ligands comprising both alkoxides
and halides. Examples of suitable alkoxide groups are those
containing from 1 to 18, preferably 2 to 8 carbon atoms, such as
ethoxide, propoxide, isopropoxide, butoxide, isobutoxide and
tert-butoxide. Examples of suitable halides are fluoride and
chloride. Other ligands such as acetyl acetonates may also be
present.
[0013] The organometallic compounds can be esters and polymeric
forms of the esters. With reference to titanium and zirconium,
examples of various compounds include [0014] a. alkyl esters of
titanium and zirconium having the general formula
(X).sub.4-y-M(OR).sub.y, wherein M is selected from Ti and Zr; X is
selected from fluorine and chlorine; R is C.sub.1-18 alkyl and y=2
to 3, [0015] b. polymeric alkyl titanates and zirconates obtainable
by condensation of the alkyl esters of (a), i.e., partially
hydrolyzed alkyl esters of the general formula
RO[-M(OR)(X)O--].sub.yR, wherein M, R and X are as above and y is a
positive integer, and [0016] c. mixtures of (a) and (b).
[0017] The organometallic compounds may be used neat and applied
under vacuum by chemical vapor deposition techniques or it may be
dissolved or dispersed in a diluent and applied by coating
techniques described below. Examples of suitable diluents are
alcohols such as methanol, ethanol and propanol, aliphatic
hydrocarbons, such as hexane, isooctane and decane, ethers, for
example, tetrahydrofuran and dialkylethers such as
diethylether.
[0018] Also, adjuvant materials may be present in the
organometallic composition. Examples include stabilizers such as
sterically hindered alcohols, surfactants and anti-static agents.
The adjuvants if present are present in amounts of up to 30 percent
by weight based on the non-volatile content of the composition.
[0019] The concentration of the organometallic compound in the
composition is not particularly critical but is usually at least
0.001 millimolar, typically from 0.01 to 100 millimolar, and more
typically from 0.1 to 50 millimolar.
[0020] The organometallic treating composition can be obtained by
mixing all of the components at the same time with low shear mixing
or by combining the ingredients in several steps. The
organometallic compounds are reactive with moisture, and care
should be taken that moisture is not introduced with the diluent or
adjuvant materials and that mixing is conducted in a substantially
anhydrous atmosphere.
[0021] Examples of substrates are those which have groups on their
surface that are reactive with functional groups associated with
the organometallic coating. Examples of such groups are oxide
and/or hydroxyl groups. Non-limiting examples of such substrates
are those which inherently have such groups on their surface or
which form such groups by subsequent treatment such as exposure to
the environment or a plasma treatment. Examples of materials which
form metal oxide surfaces upon exposure to ambient conditions
include steels, including stainless steels, iron, and metals which
acquire a non-ablating oxide coating upon exposure to the ambient
environment, for example, tantalum, titanium, titanium alloys,
aluminum, and aluminum alloys. Additional examples of materials
that acquire an oxide layer upon exposure to the ambient conditions
are ceramic materials, for example, silicon nitride. Also suitable
in the method of the present invention are materials which have an
oxide coating imparted to them, for example, thick film oxide
insulators in semiconducting devices, and those which can be
derivatized to have an oxide surface, for example, gallium
arsenide, gallium nitride, and silicon carbide. Other examples
include conducting oxides, such as indium tin oxide, deposited on a
glass substrate. Also, metal oxides can be deposited on polymer
substrates, for example, "stacked" metal oxides on polymer
substrates to provide anti-reflective properties. Examples of
polymer substrates are those that contain OH or oxide groups, such
as acrylic copolymers made from one or more monomers that contain
hydroxyl groups. Also, composite inorganic/organic polymers such as
organo polymers containing entrained silica and/or alumina may be
used. Surprisingly, it has been found that certain polymers that do
not adhere well to organometallic coatings such as described in the
aforementioned U.S. Pat. No. 6,645,644 adhere very well to the
organometallic coatings of the present invention. Examples of such
polymers are polycarbonates including aromatic and aliphatic
polycarbonates, polyurethanes, polyesters, polyepoxides, acrylic
polymers and copolymers (without hydroxyl groups) and
polysiloxanes. The polymer can be in the form of a polymer
substrate or a polymer coating on a different substrate, for
example, a metal or metal oxide with a polymer surface coating, and
a polycarbonate substrate such as an ophthalmic lens with a
polysiloxane hard coat on its surface.
[0022] Preferably, the polymer surface is oxidized such as by
subjecting the polymer to an atmospheric plasma treatment in the
presence of air before application of the organometallic
coating.
[0023] As mentioned above, the organometallic compound may be
dissolved or dispersed in a diluent and applied by conventional
means such as immersion such as dipping, rolling, spraying or
wiping to form a film. The transferred organometallic compound is
then exposed to conditions sufficient to form a polymeric metal
oxide coating in a multilayer configuration with unreacted alkoxide
and hydroxyl groups and halide groups. This can be accomplished by
depositing the film under conditions resulting in hydrolysis and
self-condensation of the alkoxide groups. These reactions result in
a polymeric coating being formed that provides cohesive strength to
the film. The conditions necessary for these reactions to occur is
to deposit the film in the presence of water, such as a
moisture-containing atmosphere. The resulting film should also have
some unreacted alkoxide groups and/or hydroxyl groups for reaction
and possible covalent bonding with the reactive groups on the
substrate surface and with possible overlayer material.
Concurrently with the self-condensation reaction, the diluent is
evaporated. Depending on the reactivity of the functional groups in
the organometallic compound and on the substrate surface, heating
may be required to bond the organometallic layer to the substrate.
For example, temperatures of 50 to 200.degree. C. may be used.
However, for readily co-reactive groups, ambient temperatures, that
is, 20.degree. C., may be sufficient. Although not intending to be
bound by any theory, it is believed the polymeric metal oxide is of
the structure:
[M(O).sub.x(OH).sub.y(OR).sub.z(Q).sub.w].sub.n
where M is the metal of the invention, R is an alkyl group
containing from 1 to 30 carbon atoms; Q is a halide group;
x+y+z+w=V, the valence of M; x, y, z and w are at least 1;
x=V-y-z-w; y=V-x-z-w; z=V-x-y-w; w=V-x-y-z; n is greater than 2,
such as 2 to 1000.
[0024] For optical applications, the resulting film typically has a
thickness of 5 to 100 nanometers. For other applications, thicker
films can be used. When the organometallic compound is used neat
and applied by chemical vapor deposition techniques in the absence
of moisture, a thin metal alkoxide film is believed to form.
Polymerization, if any occurs, is minimized and the film may be in
monolayer configuration. When the organometallic compound is
subjected to hydrolysis and self-condensation conditions as
mentioned above, thicker films with better durability are
formed.
[0025] The process of the present invention can be used to provide
a film or layer that is continuous or discontinuous, that is, in a
pattern on the substrate surface. Non-limiting examples include
spraying the composition onto a substrate in pre-determined areas,
for example, by ink jet printing or stenciling. Other methods may
be found by adapting printing techniques, including stamping,
lithographing and gravure printing a coating solution onto the
substrate in a pattern.
[0026] As mentioned above, an overlayer or a different film can be
applied to the oganometallic film. Such an overlayer material
preferably contains groups that are reactive with the alkoxide
and/or hydroxyl groups, such as hydroxyl groups or acid groups or
derivatives thereof.
[0027] Preferably, the overlayer is an organic acid or a derivative
thereof. The acid may be a carboxylic acid, a sulfonic acid or a
phosphorus acid, such as a phosphoric acid, a phosphonic acid or a
phosphinic acid. By derivatives of acids are meant functional
groups that perform similarly as acids such as acid salts, acid
esters and acid complexes. The organo group of the acid may be
monomeric, oligomeric or polymeric. For example, the organo acid
may be a monomeric, phosphoric, phosphonic or phosphinic acid.
[0028] Examples of monomeric phosphoric acids are compounds or a
mixture of compounds having the following structure:
(RO).sub.xP(O)(OR').sub.y
wherein x is 1-2, y is 1-2 and x+y=3, R is a radical having a total
of 1-30, preferably 6-18 carbons, where R' is H, a metal such as an
alkali metal, for example, sodium or potassium or lower alkyl
having 1 to 4 carbons, such as methyl or ethyl. Preferably, a
portion of R' is H. The organic component of the phosphoric acid
(R) can be aliphatic (e.g., alkyl having 2-20, preferably 6-18
carbon atoms) including an unsaturated carbon chain (e.g., an
olefin), or can be aryl or aryl-substituted moiety.
[0029] Example of monomeric phosphonic acids are compounds or
mixture of compounds having the formula:
##STR00001##
wherein x is 0-1, y is 1, z is 1-2 and x+y+z is 3. R and R'' are
each independently a radical having a total of 1-30, preferably
6-18 carbons. R' is H, a metal, such as an alkali metal, for
example, sodium or potassium or lower alkyl having 1-4 carbons such
as methyl or ethyl. Preferably at least a portion of R' is H. The
organic component of the phosphonic acid (R and R'') can be
aliphatic (e.g., alkyl having 2-20, preferably 6-18 carbon atoms)
including an unsaturated carbon chain (e.g., an olefin), or can be
an aryl or aryl-substituted moiety.
[0030] Example of monomeric phosphinic acids are compounds or
mixture of compounds having the formula:
##STR00002##
wherein x is 0-2, y is 0-2, z is 1 and x+y+z is 3. R and R'' are
each independently radicals having a total of 1-30, preferably 6-18
carbons. R' is H, a metal, such as an alkali metal, for example,
sodium or potassium or lower alkyl having 1-4 carbons, such as
methyl or ethyl. Preferably a portion of R' is H. The organic
component of the phosphinic acid (R, R'') can be aliphatic (e.g.,
alkyl having 2-20, preferably 6-18 carbon atoms) including an
unsaturated carbon chain (e.g., an olefin), or can be an aryl or
aryl-substituted moiety.
[0031] Examples of organo groups which may comprise R and R''
include long and short chain aliphatic hydrocarbons, aromatic
hydrocarbons and substituted aliphatic hydrocarbons and substituted
aromatic hydrocarbons. Examples of substituents include carboxyl
such as carboxylic acid, hydroxyl, amino, imino, amido, thio,
cyano, and fluoro.
[0032] Representative of the organophosphorous acids are as
follows: amino trismethylene phosphonic acid, aminobenzylphosphonic
acid, 3-amino propyl phosphonic acid, O-aminophenyl phosphonic
acid, 4-methoxyphenyl phosphonic acid, aminophenylphosphonic acid,
aminophosphonobutyric acid, aminopropylphosphonic acid,
benzhydrylphosphonic acid, benzylphosphonic acid, butylphosphonic
acid, carboxyethylphosphonic acid, diphenylphosphinic acid,
dodecylphosphonic acid, ethylidenediphosphonic acid,
heptadecylphosphonic acid, methylbenzylphosphonic acid,
naphthylmethylphosphonic acid, octadecylphosphonic acid,
octylphosphonic acid, pentylphosphonic acid, phenylphosphinic acid,
phenylphosphonic acid, bis-(perfluoroheptyl) phosphinic acid,
perfluorohexyl phosphonic acid, styrene phosphonic acid, dodecyl
bis-1,12-phosphonic acid.
[0033] In addition to the monomeric organophosphorous acids,
oligomeric or polymeric organophosphorous acids resulting from
self-condensation of the respective monomeric acids may be
used.
[0034] To provide hydrophobic properties to the overlayer, the
organo acid or derivative thereof is preferably a fluorinated
material, typically a perfluorinated oligomer having a number
average molecular weight of less than 2000. The perfluorinated
material can be a perfluorinated hydrocarbon of the following
structure:
R.sub.f--(CH.sub.2).sub.p--X
where R.sub.f is a perfluorinated alkyl group or a perfluorinated
alkylene ether group and p is 2 to 4, preferably 2.
[0035] Examples of perfluoroalkyl groups are those of the
structure:
##STR00003##
where Y is F or C.sub.nF.sub.2n+1; m is 4 to 20 and n is 1 to
6.
[0036] Examples of perfluoroalkylene ether groups are those of the
structure:
##STR00004##
where A is an oxygen radical or a chemical bond; n is 1 to 6; Y is
F or C.sub.nF.sub.2n+1; b is 2 to 10; W is H, F, C.sub.nH.sub.2n or
C.sub.nF.sub.2n; m is 0 to 6, and p is 0 to 18.
[0037] X is an acid group or an acid derivative. Preferably, X
is:
##STR00005##
where R and R'' are a hydrocarbon or substituted hydrocarbon
radical having up to 200, such as 1 to 30 and 6 to 20 carbons, R
can also include the perfluoroalkyl groups mentioned above, and R'
is H, a metal such as potassium or sodium or an amine or an
aliphatic radical, for example, alkyl including substituted alkyl
having 1 to 50 carbons, preferably lower alkyl having 1 to 4
carbons such as methyl or ethyl, or aryl including substituted aryl
having 6 to 50 carbons.
[0038] Examples of fluorinated materials are esters of
perfluorinated alcohols such as the alcohols of the structure:
##STR00006##
where Y is F or C.sub.nF.sub.2n+1; m is 4 to 20 and n is 1 to
6.
[0039] Examples of suitable esters are stearates and citrates of
such alcohols. Such materials are available from E. I. du Pont de
Nemours and Company under the trademark ZONYL FTS and ZONYL
TBC.
[0040] For application to the surface of the substrate, the
overlayer material is dissolved in a liquid diluent. The
concentration of the overlayer material is typically dilute, for
example, no greater than 10 percent on a weight/volume basis for
solid overlayer material and 10 percent on a volume/volume basis
for oil and liquid overlayer material, and preferably is within the
range of 0.01 to 1.0 percent. The percentages are based on total
weight or volume of the solution.
[0041] Examples of suitable diluents are hydrocarbons such as
hexane, isooctane and toluene; ketones such as methyl ethyl ketone;
alcohols such as methanol and ethanol; ethers such as
tetrahydrofuran. Fluorinated solvents such as nonafluorobutylmethyl
ether and fluorinated solvents available as HFE-7100, supplied by
3M Innovative Products and perfluorinated ethers supplied by Solvay
Solexis under the trademark GALDEN are preferred for use with the
fluorinated material. The fluorinated solvents can be used in
admixtures with the other solvents mentioned above. The fluorinated
solvents or diluents are different from the fluorinated materials
in that the fluorinated solvents or diluents are not film formers,
whereas the fluorinated materials are. Preferably, the vapor
pressure of the diluent is high, permitting rapid evaporation at
room temperature (20-25.degree. C.). The overlayer material can be
dissolved easily upon adding the overlayer material to the
diluent.
[0042] The solution of the overlayer material can be applied to the
surface of the optical article by dipping, rolling, spraying or
wiping. After application of the overlayer material, the diluent is
permitted to evaporate, with or without wiping during evaporation,
preferably at ambient temperature, or optionally by the application
of heat.
[0043] The resultant layer typically is thin, having a thickness of
about 100 nanometers or less. The fluorinated overlayers are
hydrophobic, having a water contact angle greater than 70.degree.,
typically from 75-130.degree.. The water contact angle can be
determined using a contact angle goniometer such as a TANTEC
contact angle meter Model CAM-MICRO.
EXAMPLES
[0044] The following examples show various coated articles and
methods for their preparation in accordance with the invention. All
parts are by weight unless otherwise indicated.
Example 1
[0045] A polycarbonate lens with a polysiloxane/acrylate hardcoat
was first oxidized using an electrical plasma source (Lectro-Tec)
for 10 seconds. To coat the lens with an extremely thin layer of a
polymeric tantalum metal oxide having alkoxide, chloride and
hydroxide ligands, the lens was dipped into a 1 g/L solution of
tantalum (V) chloride in isopropanol and withdrawn at a rate of 2
cm/min. The lens was then dipped in a 0.1% solution of
poly(hexafluoropropyleneoxide)-monophosphonic acid , or
"p(HFPO)PA", in 5% HFE-7100 (3M Innovative Products)/95% methanol
and ultrasonicated for 5 minutes. The lens was then withdrawn at a
rate of 2 cm/min and tested for water contact angle. The water
contact angle was determined using a contact angle Goniometer
TANTEC Contact Angle Meter, Model CAM-MICRO. The water contact
angle was 118 indicative of a very hydrophobic coating.
Example 2
[0046] In a manner similar to Example 1, a lens was coated with a
polymeric molybdenum metal oxide having isopropoxide, chloride and
hydroxide ligands and overcoated with p(HFPO)PA. The water contact
angle was 118.
Example 3
[0047] In a manner similar to Example 1, a lens was coated with a
polymeric zirconium metal oxide having dipropylene alkoxide,
chloride and hydroxide ligands and overcoated with p(HFPO)PA. The
water contact angle was 118.
Example 4
[0048] In a manner similar to Example 1, a lens was coated with a
polymeric titanium metal oxide having dipropylene alkoxide,
chloride and hydroxide ligands and overcoated with p(HFPO)PA. The
water contact angle was 116.
Example 5
[0049] In a manner similar to Example 1, a lens was coated with a
polymeric titanium metal oxide having isopropoxide, chloride and
hydroxide ligands and overcoated with p(HFPO)PA. The water contact
angle was 118.
[0050] The invention is now set forth in the following claims.
* * * * *