U.S. patent application number 13/497298 was filed with the patent office on 2012-11-22 for method of making coated metal articles.
Invention is credited to Moses M. David.
Application Number | 20120295119 13/497298 |
Document ID | / |
Family ID | 43823614 |
Filed Date | 2012-11-22 |
United States Patent
Application |
20120295119 |
Kind Code |
A1 |
David; Moses M. |
November 22, 2012 |
METHOD OF MAKING COATED METAL ARTICLES
Abstract
A method of making a coated metal article comprises (a) forming
a hardcoat layer on at least a portion of a surface of a metal or
metalized substrate by physical vapor deposition; (b) forming a tie
layer comprising silicon, oxygen, and hydrogen on at least a
portion of the surface of the hardcoat layer by plasma deposition;
and (c) applying an at least partially fluorinated composition
comprising at least one silane group to at least a portion of the
surface of the tie layer.
Inventors: |
David; Moses M.; (Woodbury,
MN) |
Family ID: |
43823614 |
Appl. No.: |
13/497298 |
Filed: |
September 17, 2010 |
PCT Filed: |
September 17, 2010 |
PCT NO: |
PCT/US10/49252 |
371 Date: |
March 21, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61247641 |
Oct 1, 2009 |
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Current U.S.
Class: |
428/447 ;
204/192.1; 204/192.38; 427/569; 427/577; 427/578; 427/579 |
Current CPC
Class: |
A63B 2209/00 20130101;
A63B 2210/50 20130101; A63B 60/10 20151001; A63B 53/0487 20130101;
Y10T 428/31663 20150401; C23C 14/0641 20130101; A63B 53/005
20200801; A63B 60/06 20151001; A63B 2209/02 20130101; A63B 53/007
20130101; A63B 60/08 20151001; A63B 53/14 20130101; A63B 60/22
20151001; A63B 53/12 20130101; B25G 3/26 20130101 |
Class at
Publication: |
428/447 ;
427/569; 427/579; 427/578; 427/577; 204/192.38; 204/192.1 |
International
Class: |
C23C 14/06 20060101
C23C014/06; C23C 16/40 20060101 C23C016/40; C23C 16/30 20060101
C23C016/30; B32B 27/06 20060101 B32B027/06; C23C 16/26 20060101
C23C016/26; C23C 14/24 20060101 C23C014/24; C23C 14/35 20060101
C23C014/35; C23C 14/04 20060101 C23C014/04; C23C 16/50 20060101
C23C016/50; C23C 16/32 20060101 C23C016/32 |
Claims
1. A method of making a coated metal article comprising: (a)
forming a hardcoat layer on at least a portion of a surface of a
metal or metalized substrate by physical vapor deposition; (b)
forming a tie layer comprising silicon, oxygen, and hydrogen on at
least a portion of the surface of the hardcoat layer by plasma
deposition; (c) applying an at least partially fluorinated
composition comprising at least one silane group to at least a
portion of the surface of the tie layer.
2. The method of claim 1 wherein the hardcoat layer is formed by
cathodic arc, sputtering, thermal evaporation, or e-beam
evaporation.
3. The method of claim 1 wherein the hardcoat layer comprises a
metal nitride or a mixed metal nitride.
4. The method of claim 3 wherein the hardcoat layer comprises at
least one of titanium nitride, zirconium nitride, aluminum nitride,
or titanium aluminum nitride.
5-7. (canceled)
8. The method of claim 1 wherein forming the tie layer comprises
ionizing a gas comprising at least one of an organosilicon or a
silane compound.
9. The method of claim 1 wherein the tie layer further comprises at
least one of carbon, diamond-like glass, silicon oxycarbide,
silicon carbide, silicon oxide, silicon dioxide, silicon nitride,
or silicon oxynitride.
10-15. (canceled)
16. The method of claim 1 wherein the at least partially
fluorinated composition comprising at least one silane group is a
quat silane of Formula V: ##STR00004## wherein b and c is each
independently an integer of 1 to 3; R.sub.f is a perfluorinated
ether group; A is a linking group having the formula
--C.sub.dH.sub.2dZC.sub.gH.sub.2g--, wherein d and g are
independently integers from 0 to 10 and Z is selected from the
group consisting of a covalent bond, a carbonyl group, a sulfonyl
group, a carboxamido group, a sulfonamido group, an iminocarbonyl
group, an iminosulfonyl group, an oxycarbonyl group, a urea group,
a urethane group, a carbonate group, and a carbonyloxy group; Y is
a bridging group having 1 to 10 carbon atoms, a valency of 2 to 6,
and comprising at least one of an alkylene group or an arylene
group; Q is a connecting group having 1 to 10 carbon atoms, a
valency of 2 to 6, and comprising at least one of an alkylene group
or an arylene group; R.sup.1 and R.sup.2 are independently selected
from the group consisting of a hydrogen atom, an alkyl group, an
aryl group, and an aralkyl group; each R.sup.3 is independently
selected from the group consisting of hydroxy groups, alkoxy
groups, acyl groups, acyloxy groups, halo groups, and polyether
groups; and X.sup.- is a counter ion selected from the group
consisting of inorganic anions, organic anions, and combinations
thereof.
17. The method of claim 1 wherein the at least partially
fluorinated composition comprising at least one silane group is a
quat silane of Formula VI: ##STR00005## wherein R.sub.f has the
structure
--CF(CF.sub.3)(OCF.sub.2CF(CF.sub.3)).sub.mOCF.sub.2CF.sub.2CF.sub.2CF.su-
b.2O(CF(CF.sub.3)CF.sub.2O).sub.nCF(CF.sub.3)--, wherein m is an
integer of 1 to 12 and n is an integer of 2 to 10; c is an integer
from about 1 to about 3; A is a linking group having the formula
--C.sub.dH.sub.2dZC.sub.gH.sub.2g--, wherein d and g are
independently integers from about 0 to about 10 and Z is selected
from the group consisting of a covalent bond, a carbonyl group, a
sulfonyl group, a carboxamido group, a sulfonamido group, an
iminocarbonyl group, an iminosulfonyl group, an oxycarbonyl group,
a urea group, a urethane group, a carbonate group, and a
carbonyloxy group; Y is a bridging group comprising an alkylene
group having about 1 to about 6 carbon atoms; Q is a connecting
group comprising an alkylene group having about 1 to about 6 carbon
atoms; R.sup.1 and R.sup.2 are independently alkyl groups having
about 1 to about 4 carbon atoms; each R.sup.3 is independently
selected from the group consisting of hydroxy groups, methoxy
groups, ethoxy groups, acetoxy groups, chloro groups, and polyether
groups; and X.sup.- is a counter ion selected from the group
consisting of a halide, sulfate, phosphate, an alkyl sulfonate, an
aryl sulfonate, an alkyl phosphonate, an aryl phosphonate, a
fluorinated alkyl sulfonate, a fluorinated aryl sulfonate, a
fluorinated alkyl sulfonimide, a fluorinated alkyl methide, and
combinations thereof.
18. The method of claim 1 wherein the at least partially
fluorinated composition comprising at least one silane group
comprises hexafluoropropyleneoxide.
19. The method of claim 1 wherein the at least partially
fluorinated composition comprising at least one silane group
comprises a composition comprising: (a) a first polyfluoropolyether
silane of the Formula VIIa:
CF.sub.3CF.sub.2CF.sub.2O(CF(CF.sub.3)CF.sub.2O).sub.pCF(CF.sub.3)--C(O)N-
H(CH.sub.2).sub.3Si(Y).sub.3 VIIa wherein each Y is independently a
hydrolyzable group and wherein p is 3 to 50; and (b) a second
polyfluoropolyether silane of the Formula IIXa:
(Y').sub.3Si(CH.sub.2).sub.3NHC(O)--CF.sub.2O(CF.sub.2O).sub.m(C.sub.2F.s-
ub.4O).sub.qCF.sub.2--C(O)NH(CH.sub.2).sub.3Si(Y').sub.3 IIXa
wherein each Y' is independently a hydrolyzable group and wherein m
is 1 to 50 and q is 3 to 40.
20. The method of claim 1 wherein the at least partially
fluorinated composition comprising at least one silane group
comprises a composition comprising: (a) a first polyfluoropolyether
silane entity of the Formula VIIb:
CF.sub.3CF.sub.2CF.sub.2O(CF(CF.sub.3)CF.sub.2O).sub.pCF(CF.sub.3)-
--C(O)NH(CH.sub.2).sub.3Si(O--).sub.3 VIIb wherein p is 3 to 50;
and (b) a second polyfluoropolyether silane entity of the Formula
IIXb:
(--O).sub.3Si(CH.sub.2).sub.3NHC(O)--CF.sub.2O(CF.sub.2O).sub.m(C.sub.2F.-
sub.4O).sub.qCF.sub.2--C(O)NH(CH.sub.2).sub.3Si(O--).sub.3 IIXb
wherein m is 1 to 50 and q is 3 to 40.
21. The method of claim 1 wherein the hardcoat layer is formed
using cathodic arc deposition, the tie layer is formed using
ion-assisted plasma deposition, and the at least partially
fluorinated composition is applied by thermal evaporation and
condensation of the composition.
22. The method of claim 21 wherein the hardcoat layer is formed,
the tie layer is formed, and the at least partially fluorinated
composition is applied within a single deposition chamber.
23. The method of claim 1 wherein the metal or metalized substrate
comprises stainless steel.
24. A coated metal article comprising: (a) a metal or metalized
substrate; (b) a physical vapor deposited hardcoat layer disposed
on at least a portion of the metal or metalized substrate; (c) a
plasma deposited tie layer comprising silicon, oxygen, and hydrogen
disposed on at least a portion of the surface of the hardcoat
layer; and (d) an at least partially fluorinated composition
comprising at least one silane group disposed on at least a portion
of the surface of the tie layer.
25. The coated metal article of claim 24 wherein the article is a
cutting tool or element.
26. The coated metal article of claim 24 wherein the article is a
kitchen or bathroom fixture or appliance.
27. The coated metal article of claim 24 wherein the hardcoat layer
comprises a metal nitride or a mixed metal nitride.
28. The coated metal article of claim 24 wherein the tie layer
further comprises carbon.
29. The coated metal article of claim 24 wherein the at least
partially fluorinated composition comprising at least one silane
group comprises hexafluoropropyleneoxide.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 61/247,641, filed Oct. 1, 2009, the
disclosure of which is incorporated by reference herein in its
entirety.
FIELD
[0002] This invention relates to a method of making durable easy
clean metal articles and to durable easy clean coated metal
articles.
BACKGROUND
[0003] Metal articles are used for various applications. Examples
of functional metal articles include scissor blades, paper cutters
and shredders, shaving blades, cutting tools, stamping dies, molds,
bathroom and kitchen fixtures and appliances, automotive wheels and
rims, and the like.
[0004] Metal articles, however, can be prone to contamination from
handling and/or from the environment in which they are utilized.
For example, scissor blades can be contaminated by adhesive residue
when they are used to cut adhesive tapes; bathroom fixtures can be
contaminated by soap scum and calcification; kitchen appliances and
fixtures can be contaminated by cooking oils and greases;
automotive wheels and rims can be contaminated by automotive oils,
dirt, and grease; and cutting tools can be contaminated by
machining oils and wear debris resulting from the cutting
operations.
[0005] When metal articles are used for cutting or machining
operations, contamination can cause the cutting edges of the
articles to become dulled due to the aggressive wear created by the
contaminants. In the case of stamping dies or other dies such as
extrusion or molding dies, contamination can compromise the quality
of the product produced by the dies. In other cases such as
bathroom and kitchen fixtures and appliances, automotive wheels and
rims, and the like, contamination can cause deterioration of the
aesthetics or appearance of the articles.
[0006] Various methods have been used to address the problem of
contamination of metal articles. For example, topical treatments or
coatings that have low surface energy have been employed. Low
surface energy prevents the contaminants from accumulating on the
surface of metal articles. Such coatings typically include low
surface energy materials such as silicone, fluorosilicones, or
fluoropolymers such as polytetrafluoroethylene (PTFE), fluorinated
ethylene propylene (FEP), ethylene-tetrafluoroethylene (ETFE), or
the like.
[0007] While such low surface energy coatings can be effective in
preventing the contamination of metal articles, they do not
typically have the durability that is required for many
applications.
[0008] Scissors blades, for example, are often coated with a
non-stick coating comprising pigmented PTFE coatings or silicone
oil. PTFE coatings are typically applied thickly and then the edges
of the scissor blades are ground so that they will cut paper and/or
cloth. PTFE coatings are soft and abrade quickly, however, due to
flank wear on the scissors during use. This exposes the bare metal
(for example, stainless steel) and allows adhesive residue to build
up. Similarly, silicone oil works well initially, but wears off and
is easily removed by wiping or by removing tape from the surface of
the blades. After the silicone oil is removed, adhesive residue can
build up on the blades.
[0009] In addition, many of the above coatings change the color or
appearance of the underlying metal and diminish the luster of the
metal.
SUMMARY
[0010] In view of the foregoing, we recognize that there is a need
in the art for improved metal articles with surfaces that resist
the accumulation of contaminants, that are easy to clean, and that
remain stable over time and with use (that is, they are durable),
but that maintain the luster and color of the underlying metal. In
one aspect, the present invention provides a method of making a
metal article.
[0011] The method comprises (a) forming a hardcoat layer on at
least a portion of a surface of a metal or metalized substrate by
physical vapor deposition, (b) forming a tie layer comprising
silicon, oxygen, and hydrogen on at least a portion of the surface
of the hardcoat layer by plasma deposition, and (c) applying an at
least partially fluorinated composition comprising at least one
silane group to at least a portion of the surface of the tie
layer.
[0012] In another aspect, the present invention provides a coated
metal article comprising (a) a metal or metalized substrate, (b) a
physical vapor deposited hardcoat layer disposed on at least a
portion of the metal or metalized substrate, (c) a plasma deposited
tie layer comprising silicon, oxygen, and hydrogen disposed on at
least a portion of the surface of the hardcoat layer, and (d) an at
least partially fluorinated composition comprising at least one
silane group disposed on at least a portion of the surface of the
tie layer.
[0013] The method of the invention provides coated metal articles
that resist the accumulation of contamination and that are easy to
clean. The coated metal articles maintain the luster and color of
the underlying metal while remaining clean without degrading upon
repeated use. Scissors coated according to the method of the
invention, for example, can maintain their easy clean (i.e.,
non-stick) properties after 10,000 cuts.
DETAILED DESCRIPTION
[0014] The method of the invention for making a coated metal
article comprises forming a hardcoat layer on a surface of a metal
or metalized substrate by physical vapor deposition.
[0015] As used herein, "metal or metalized substrate" refers to a
substrate comprised of a metal and/or metal alloy, which is solid
at room temperature. The metal and/or metal alloy can be selected,
for example, from the group consisting of chromium, iron, aluminum,
copper, nickel, zinc, tin, stainless steel, and brass, and the
like, and alloys thereof. For certain of these embodiments, the
metal and/or metal alloy is chromium or stainless steel. A metal
substrate comprises one or more metals and/or metal alloys at a
major surface and one or more metals and/or metal alloys throughout
the body of the substrate. A metalized substrate also comprises one
or more metals and or metal alloys at a major surface. The
metalized substrate can further comprise a polymeric material,
which includes one or both of thermoset and thermoplastic polymers,
ceramic, glass, porcelain, as well as other materials capable of
having a metalized surface.
[0016] Examples of metal or metalized substrates include, but are
not limited to, kitchen and bathroom faucets, taps, handles,
spouts, sinks, drains, hand rails, towel holders, curtain rods,
dish washer panels, refrigerator panels, stove tops, stove, oven,
and microwave panels, exhaust hoods, grills, metal wheels or rims,
scissor blades, paper cutters, paper shredders, shaving blades,
cutting tools, stamping dies, molds, and the like.
[0017] In preferred embodiments, the metal or metalized substrate
is a cutting tool or element such as, for example, scissors, paper
shredders, razor blades, knives, kitchen cutlery, butcher tools,
woodworking tools, metalworking tools, and the like. The scissors
can be used for a variety of applications including, for example,
cutting paper, plastic, fabric, or hair. Woodworking tools can
include, for example, drill bits, cutting wires, saw blades, and
the like.
[0018] Forming a hardcoat layer on at least a portion of a surface
of the substrate by physical vapor deposition (PVD) can be carried
out using PVD methods known in the art. As used herein, "physical
vapor deposition" or "PVD" refers to coating wherein at least one
of the coating components is initially placed into the coating
chamber in a non-gaseous form. The non-gaseous coating component is
generally called the "source." The coating chamber is typically
evacuated to sub-atmospheric pressure prior to and during the
coating process. Sufficient energy is applied to the source
material to change it to vapor state, which vapor subsequently
comes to rest in film form on the substrates, often after combining
with other components. Electrostatic and/or electromagnetic fields
may be used in the process of converting the source material to its
vapor phase as well as to direct the coating particles toward the
substrate.
[0019] Useful known PVD methods include, for example, sputtering,
reactive sputtering, evaporation, reactive evaporation,
ion-assisted reactive evaporation, ion-beam assisted deposition,
cathodic arc evaporation, unbalanced magnetron sputtering, high
power impulse magnetron sputtering (HIPIMS), thermal and electron
beam (e-beam) evaporation, and the like.
[0020] PVD apparatuses known in the art such as the apparatus
disclosed in U.S. Pat. No. 4,556,471 (Bergman et al.) can be
utilized.
[0021] The substrate to be treated may by pre-cleaned by methods
known to the art to remove contaminants that may interfere with the
plasma deposition. One useful pre-cleaning method is exposure to an
oxygen plasma. For this pre-cleaning, pressures in the chamber are
maintained between 1.3 Pa (10 mTorr) and 27 Pa (200 mTorr). Plasma
is generated with RF power levels of between 500 W and 3000 W.
[0022] A solvent washing step with an organic solvent such as
acetone or ethanol or acid etch treatment may also be included
prior to the exposure to oxygen plasma.
[0023] The hardcoat layer can comprise nitrides, carbides and
oxides of titanium, chromium, zirconium, niobium, aluminum, mixed
metal nitrides (for example, aluminum-titanium nitride,
chromium-aluminum nitride, or zirconium-chromium nitride),
diamond-like carbon, tetrahedral amorphous carbon, and the like.
The hardcoat layer can comprise multilayer films of nitrides,
carbides, oxides, and the like.
[0024] Preferred hardcoats include metal nitrides and mixed metal
nitrides such as, for example, nitrides Of titanium, aluminum,
chromium, tantalum, niobium, and the like. Titanium nitride,
zirconium nitride, aluminum nitride, and titanium aluminum nitride
are particularly useful.
[0025] Typically, the hardcoat layer is from about 0.1 to about 50
microns thick; preferably, about 0.5 to 10 microns thick.
[0026] Forming a tie layer comprising silicon, oxygen, and hydrogen
on at least a portion of the surface of the hardcoat layer by
plasma deposition can be carried out in a suitable reaction chamber
having a capacitively-coupled system with at least one electrode
powered by an RF (radio frequency) source and at least one grounded
electrode, such as those described in U.S. Pat. Nos. 6,696,157
(David et al.) and 6,878,419 (David et al.).
[0027] The substrate with the hardcoat layer is either located on
the powered electrode or the assembly holding the coated metal
article(s) is powered with an RF power supply. The articles for
coating are located in a vacuum chamber, and the chamber is
evacuated to the extent necessary to remove air and any impurities.
This may be accomplished by vacuum pumps at a pumping stack
connected to the chamber. A source gas is introduced into the
chamber at a desired flow rate, which depends on the size of the
reactor, the surface area of the electrodes, and the surface area
of the substrate. Precleaning of the substrate/article can be done
with a suitable gas such as argon, nitrogen, or oxygen. An oxygen
plasma can be particularly effective in cleaning any organic
contaminants from the substrate surface before deposition of the
hardcoat. During plasma deposition, the gas includes an
organosilicon and/or a silane compound, and the flow rates are
sufficient to establish a suitable pressure at which to carry out
plasma deposition, typically 0.13 Pa to 130 Pa (0.001 Ton to 1.0
Ton). For a cylindrical reactor that has an inner diameter of
approximately 55 cm and a height of approximately 20 cm, the flow
rates are typically from about 50 to about 500 standard cubic
centimeters per minute (sccm). At the pressures and temperatures
(less than about 50.degree. C.) of the plasma deposition, the gas
remains in the vapor form. An RF electric field is applied to the
powered electrode, ionizing the gas and establishing a plasma. In
the RF-generated plasma, energy is coupled into the plasma through
electrons. The plasma acts as the charge carrier between the
electrodes. The plasma can fill the entire reaction chamber and is
typically visible as a colored cloud.
[0028] The plasma also forms an ion sheath proximate the
substrate/article or on the electrode. The ion sheath typically
appears as a darker area around the substrate/article or electrode.
Within the ion sheath, ions accelerating toward the electrode
bombard the species being deposited from the plasma onto the
substrate, positively impacting the adhesion and density/hardness
of the deposited layer. The depth of the ion sheath normally ranges
from about 1 mm to about 50 mm and depends on factors such as the
type and concentration of gas used, pressure in the chamber, the
spacing between the electrodes, and relative size of the
electrodes. For example, reduced pressures will increase the size
of the ion sheath. When the electrodes are different sizes, a
larger, stronger ion sheath will form around the smaller electrode.
Generally, the larger the difference in electrode size, the larger
the difference in the size of the ion sheaths, and increasing the
voltage across the ion sheath will increase ion bombardment
energy.
[0029] The substrate comprising the hardcoat layer is exposed to
the ion bombarded species being deposited from the plasma. The
resulting reactive species within the plasma react on the surface
of the hardcoat layer, forming another layer, the composition of
which is controlled by the composition of the gas being ionized in
the plasma. The species forming this layer can attach to the
surface of the hardcoat layer by covalent bonds.
[0030] For certain embodiments, forming the layer comprising the
silicon, oxygen, and hydrogen comprises ionizing a gas comprising
at least one of an organosilicon or a silane compound. For certain
of these embodiments, the silicon of the at least one of an
organosilicon or a silane compound is present in an amount of at
least about 5 atomic percent of the gas mixture. Thus, if a
reactive gas such as oxygen or an inert gas such as argon are mixed
along with the organosilicon or silane precursor, the atomic
percent of silicon in the gas mixture is calculated based on the
volumetric (or molar) flow rates of the component gases in the
mixture. For certain of these embodiments, the gas comprises the
organosilicon. For certain of these embodiments, the organosilicon
comprises at least one of trimethylsilane, triethylsilane,
trimethoxysilane, triethoxysilane, tetramethylsilane,
tetraethylsilane, tetramethoxysilane, tetraethoxysilane,
hexamethylcyclotrisiloxane, tetramethylcyclotetrasiloxane,
tetraethylcyclotetrasiloxane, octamethylcyclotetrasiloxane,
hexamethyldisiloxane, and bistrimethylsilylmethane. For certain of
these embodiments, the organosilicon comprises tetramethylsilane.
In addition to or alternatively, for certain of these embodiments,
the gas comprises the silane compound. For certain of these
embodiments, the silane compound comprises one or more of SiH.sub.4
(silicon tetrahydride), Si.sub.2H.sub.6 (disilane), and SiClH.sub.3
(chlorosilane). For certain of these embodiments, the silane
compound comprises SiH.sub.4 (silicon tetrahydride).
[0031] For certain embodiments, including any one of the above
embodiments, preferably the gas further comprises oxygen.
[0032] For certain embodiments, including any one of the above
embodiments, the gas further comprises at least one of argon,
ammonia, hydrogen, and nitrogen. Each additional gas can be added
separately or in combination with each other. For certain of these
embodiments, the gas further comprises at least one of ammonia,
hydrogen, and nitrogen such that the total amount of the at least
one of ammonia, hydrogen, and nitrogen is at least about 5 molar
percent and not more than about 50 molar percent of the gas.
[0033] Plasma deposition of the layer typically occurs at a rate
ranging from about 1 to about 100 nm/second. The rate will depend
on conditions including pressure, power, concentration of gas,
types of gases, relative size of the electrodes, and so on. In
general, the deposition rate increases with increasing power,
pressure, and concentration of gas, although the rate can approach
an upper limit.
[0034] For certain embodiments, including any one of the above
embodiments, the plasma deposition of the layer comprising the
silicon, oxygen, and hydrogen is carried out for a period of time
not less than about 2 seconds, not less than about 5 seconds, or
not less than about 10 seconds.
[0035] For certain embodiments, including any one of the above
embodiments, the plasma deposition of the layer comprising the
silicon, oxygen, and hydrogen is carried out for a period of time
not more than about 30 seconds, about 20 seconds, or about 15
seconds.
[0036] For certain embodiments, including any one of the above
embodiments, the plasma deposition of the layer comprising the
silicon, oxygen, and hydrogen is carried out for a period of time
not less than about 5 seconds and not more than about 15 seconds.
For certain of these embodiments, the period of time is about 10
seconds.
[0037] For certain embodiments, including any one of the above
embodiments, the substrate comprising the hardcoat layer is exposed
to an oxygen plasma prior to the plasma deposition of the layer
comprising the silicon, oxygen, and hydrogen.
[0038] After the layer comprising the silicon, oxygen, and hydrogen
is formed by plasma deposition, the surface of the layer may be
exposed to an oxygen plasma to form silanol groups or to form
additional silanol groups on the surface of the layer. For this
post-treatment, pressures in the chamber are maintained between 1.3
Pa (10 mTorr) and 27 Pa (200 mTorr). The oxygen plasma is generated
with RF power levels of between about 50 W and about 3000 W.
[0039] For certain embodiments, including any one of the above
embodiments, after deposition is complete, the layer comprising the
silicon, oxygen, and hydrogen is exposed to an oxygen plasma.
[0040] For certain embodiments, including any one of the above
embodiments, the tie layer comprising silicon, oxygen, and hydrogen
preferably further comprises carbon. The presence of the carbon can
impart an increased flexibility and toughness to the layer. Useful
tie layers comprising silicon, oxygen, hydrogen, and carbon
include, for example, silicon dioxide, silicon monoxide,
sub-stoichiometric silicon oxide, silicon carbide, silicon
oxycarbide, silicon oxynitride, silicon nitride, diamond-like
glass, silicon doped diamond-like carbon, and the like. Preferred
ties layer comprise diamond-like glass, silicon oxide, silicon
dioxide, silicon carbide, silicon nitride, silicon oxynitride, or
silicon oxycarbide.
[0041] Typically, the tie layer is from about 0.001 to about 1
micron thick; preferably, from about 0.01 to about 0.1 microns
thick.
[0042] After the tie layer has been formed, an at least partially
fluorinated composition comprising at lease one silane group is
applied to at least a portion of the surface of the tie layer. As
used herein, the "at least partially fluorinated composition
comprising at least one silane group" refers to at least one of
polyfluoropolyether silanes, perfluoroalkyl silanes, fluorinated
oligomeric silanes, or swallow-tail silanes. In one embodiment, the
at least partially fluorinated composition comprising at least one
silane group is a polyfluoropolyether silane. Polyfluoropolyether
silanes are represented by the Formula I:
R.sub.f{-Q-[SiY.sub.3-x(R.sup.1).sub.x].sub.y}.sub.z I
wherein R.sub.f is a monovalent or multivalent polyfluoropolyether
segment; Q is an organic divalent or trivalent linking group; each
Y is independently a hydrolyzable group; R.sup.1 is an alkyl group
or a phenyl group; x is 0 or 1 or 2; y is 1 or 2, and z is 1, 2, 3,
or 4.
[0043] The monovalent or multivalent polyfluoropolyether segment,
R.sub.f, includes linear, branched, and/or cyclic structures that
may be saturated or unsaturated, and includes two or more in-chain
oxygen atoms. R.sub.f is preferably a perfluorinated group (i.e.,
all C--H bonds are replaced by C--F bonds). However, hydrogen or
chlorine atoms may be present instead of fluorine atoms provided
that not more than one atom of either hydrogen or chlorine is
present for every two carbon atoms. When hydrogen and/or chlorine
are present, preferably, R.sub.f includes at least one
perfluoromethyl group.
[0044] The organic divalent or trivalent linking group, Q, can
include linear, branched, or cyclic structures that may be
saturated or unsaturated. The organic divalent or trivalent linking
group, Q, optionally contains one or more heteroatoms selected from
the group consisting of sulfur, oxygen, and nitrogen, and/or
optionally contains one or more functional groups selected from the
group consisting of esters, amides, sulfonamides, carbonyl,
carbonates, ureylenes, and carbamates. Q includes not less than 2
carbon atoms and not more than about 25 carbon atoms. Q is
preferably substantially stable against hydrolysis. When more than
one Q groups are present, the Q groups can be the same or
different.
[0045] For certain embodiments, including any one of the above
embodiments, Q includes organic linking groups such as
--C(O)N(R)--(CH.sub.2).sub.k--,
--S(O).sub.2N(R)--(CH.sub.2).sub.k--, --(CH.sub.2).sub.k--,
--CH.sub.2O--(CH.sub.2).sub.k--, --C(O)S--(CH.sub.2).sub.k--,
--CH.sub.2OC(O)N(R)--(CH.sub.2).sub.k--, and
##STR00001##
wherein R is hydrogen or C.sub.1-4 alkyl, and k is 2 to about 25.
For certain of these embodiments, k is 2 to about 15 or 2 to about
10.
[0046] The hydrolyzable groups, Y, may be the same or different and
are capable of hydrolyzing, for example, in the presence of water,
optionally under acidic or basic conditions, producing groups
capable of undergoing a condensation reaction, for example silanol
groups.
[0047] For certain embodiments, including any one of the above
embodiments, the polyfluoropolyether silane is of the Formula
Ia:
R.sub.f[Q'-C(R).sub.2--Si(Y').sub.3-x(R.sup.1a).sub.x].sub.z Ia
[0048] wherein: [0049] R.sub.f is a monovalent or multivalent
polyfluoropolyether segment; [0050] Q' is an organic divalent
linking group; [0051] each R is independently hydrogen or a
C.sub.1-4 alkyl group; [0052] each Y' is a hydrolysable group
independently selected from the group consisting of halogen,
alkoxy, acyloxy, polyalkyleneoxy, and aryloxy groups; [0053]
R.sup.1a is a C.sub.1-8 alkyl or phenyl group; [0054] x is 0 or 1
or 2; and [0055] z is 1, 2, 3, or 4.
[0056] For certain embodiments, including any one of the above
embodiments of Formulas I or Ia, the monovalent or multivalent
polyfluoropolyether segment, R.sub.f, comprises perfluorinated
repeating units selected from the group consisting of
--(C.sub.nF.sub.2n)--, --(C.sub.nF.sub.2nO)--, --(CF(Z))--,
--(CF(Z)O)--, --(CF(Z)C.sub.nF.sub.2nO)--,
--(C.sub.nF.sub.2nCF(Z)O)--, --(CF.sub.2CF(Z)O)--, and combinations
thereof; Z is a perfluoroalkyl group, an oxygen-containing
perfluoroalkyl group, a perfluoroalkoxy group, or an
oxygen-substituted perfluoroalkoxy group, each of which can be
linear, branched, or cyclic, and have 1 to 9 carbon atoms and up to
4 oxygen atoms when oxygen-containing or oxygen-substituted; and n
is an integer from 1 to 12. Being oligomeric or polymeric in
nature, these compounds exist as mixtures and are suitable for use
as such. The perfluorinated repeating units may be arranged
randomly, in blocks, or in an alternating sequence. For certain of
these embodiments, the polyfluoropolyether segment comprises
perfluorinated repeating units selected from the group consisting
of --(C.sub.nF.sub.2nO)--, --(CF(Z)O)--,
--(CF(Z)C.sub.nF.sub.2nO)--, --(C.sub.nF.sub.2nCF(Z)O)--,
--(CF.sub.2CF(Z)O)--, and combinations thereof. For certain of
these embodiments, n is an integer from 1 to 12, 1 to 6, 1 to 4, or
1 to 3.
[0057] For certain embodiments, including any one of the above
embodiments, R.sub.f is monovalent, and z is 1. For certain of
these embodiments, R.sub.f is terminated with a group selected from
the group consisting of C.sub.nF.sub.2n+1--, C.sub.nF.sub.2n+1O--,
and X'C.sub.nF.sub.2nO-- wherein X' is a hydrogen or chlorine atom.
For certain of these embodiments, the terminal group is
C.sub.nF.sub.2n+1-- or C.sub.nF.sub.2n+1O-- wherein n is an integer
from 1 to 6 or 1 to 3. For certain of these embodiments, the
approximate average structure of R.sub.f is
C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.pCF(CF.sub.3)-- or
CF.sub.3O(C.sub.2F.sub.4O).sub.pCF.sub.2-- wherein the average
value of p is 3 to 50.
[0058] For certain embodiments, including any one of the above
embodiments except where R.sub.f is monovalent, R.sub.f is
divalent, and z is 2. For certain of these embodiments, R.sub.f is
selected from the group consisting of
--CF.sub.2O(CF.sub.2O).sub.m(C.sub.2F.sub.4O).sub.pCF.sub.2--,
--CF(CF.sub.3)--(OCF.sub.2CF(CF.sub.3)).sub.pO--R.sub.f'--O(CF(CF.sub.3)C-
F.sub.2O).sub.pCF(CF.sub.3)--,
--CF.sub.2O(C.sub.2F.sub.4O).sub.pCF.sub.2--, and
--(CF.sub.2).sub.3O(C.sub.4F.sub.8O).sub.p(CF.sub.2).sub.3--, and
wherein R.sub.f' is a divalent, perfluoroalkylene group containing
at least one carbon atom and optionally interrupted in chain by O
or N, m is 1 to 50, and p is 3 to 40. For certain of these
embodiments, R.sub.f' is (C.sub.nF.sub.2n), wherein n is 2 to 4.
For certain of these embodiments, R.sub.f is selected from the
group consisting of
--CF.sub.2O(CF.sub.2O).sub.m(C.sub.2F.sub.4O).sub.pCF.sub.2--,
--CF.sub.2O(C.sub.2F.sub.4O).sub.pCF.sub.2--, and
--CF(CF.sub.3)--(OCF.sub.2CF(CF.sub.3)).sub.pO--(C.sub.nF.sub.2n)--O(CF(C-
F.sub.3)CF.sub.2O).sub.pCF(CF.sub.3)--, and wherein n is 2 to 4,
and the average value of m+p or p+p or p is from about 4 to about
24.
[0059] The above described polyfluoropolyether silanes typically
include a distribution of oligomers and/or polymers, so p and m may
be non-integral. The above structures are approximate average
structures where the approximate average is over this distribution.
These distributions may also contain perfluoropolyethers with no
silane groups or more than two silane groups. Typically,
distributions containing less than about 10% by weight of compounds
without silane groups can be used.
[0060] For certain embodiments, including any one of the above
embodiments where the organic divalent linking group, Q' is
present, Q' is a saturated or unsaturated hydrocarbon group
including 1 to about 15 carbon atoms and optionally containing 1 to
4 heteroatoms and/or 1 to 4 functional groups. For certain of these
embodiments, Q' is a linear hydrocarbon containing 1 to about 10
carbon atoms, optionally containing 1 to 4 heteroatoms and/or 1 to
4 functional groups. For certain of these embodiments, Q' contains
one functional group. For certain of these embodiments, Q' is
preferably --C(O)N(R)(CH.sub.2).sub.2--,
--OC(O)N(R)(CH.sub.2).sub.2--, --CH.sub.2--O--(CH.sub.2).sub.2--,
or --CH.sub.2--OC(O)N(R)--(CH.sub.2).sub.2--, wherein R is hydrogen
or C.sub.1-4 alkyl.
[0061] For certain embodiments, including any one of the above
embodiments where R is present, R is hydrogen.
[0062] For certain embodiments, including any one of the above
embodiments where the hydrolyzable group Y or Y' is present, each Y
or Y' is independently a group such as halogen, alkoxy, acyloxy,
aryloxy, and polyalkyleneoxy. Alkoxy is --OR', and acyloxy is
--OC(O)R', wherein each R' is independently a lower alkyl group,
optionally substituted by one or more halogen atoms. For certain
embodiments, R' is preferably C.sub.1-6 alkyl and more preferably
C.sub.1-4 alkyl. Aryloxy is --OR'' wherein R'' is aryl optionally
substituted by one or more substituents independently selected from
halogen atoms and C.sub.1-4 alkyl optionally substituted by one or
more halogen atoms. For certain embodiments, R'' is preferably
unsubstituted or substituted C.sub.6-12 aryl and more preferably
unsubstituted or substituted C.sub.6-10 aryl. Polyalkyleneoxy is
--O--(CHR.sup.4--CH.sub.2O).sub.q--R.sup.3 wherein R.sup.3 is
C.sub.1-4 alkyl, R.sup.4 is hydrogen or methyl, with at least 70%
of R.sup.4 being hydrogen, and q is 1 to 40, preferably 2 to
10.
[0063] For certain embodiments, including any one of the above
embodiments, x is 0.
[0064] For certain embodiments, the number average molecular weight
of the polyfluoropolyether silane is about 750 to about 6000,
preferably about 800 to about 4000.
[0065] For certain embodiments, including any one of the above
embodiments, particularly of Formula Ia, R.sub.f is
--CF.sub.2O(CF.sub.2O).sub.m(C.sub.2F.sub.4O).sub.pCF.sub.2--, and
Q'-C(R).sub.2--Si(Y').sub.3-x(R.sup.1a).sub.x is
C(O)NH(CH.sub.2).sub.3Si(OR').sub.3 wherein R' is methyl or ethyl.
For certain of these embodiments, m and p are each about 9 to
12.
[0066] The compounds of Formulas I and Ia described above can be
synthesized using standard techniques. For example, commercially
available or readily synthesized perfluoropolyether esters (or
functional derivatives thereof) can be combined with a
functionalized alkoxysilane, such as a 3-aminopropylalkoxysilane,
according to U.S. Pat. No. 3,810,874 (Mitsch et al.). It will be
understood that functional groups other than esters may be used
with equal facility to incorporate silane groups into a
perfluoropolyether.
[0067] Perfluoropolyether diesters, for example, may be prepared
through direct fluorination of a hydrocarbon polyether diester.
Direct fluorination involves contacting the hydrocarbon polyether
diester with F.sub.2 in a diluted form. The hydrogen atoms of the
hydrocarbon polyether diester will be replaced with fluorine atoms,
thereby generally resulting in the corresponding perfluoropolyether
diester. Direct fluorination methods are disclosed in, for example,
U.S. Pat. Nos. 5,578,278 (Fall et al.) and 5,658,962 (Moore et
al.).
[0068] In another embodiment, the at least partially fluorinated
composition comprising one or more a silane groups is a
perfluoroalkyl silane of the following Formula II:
R.sup.2.sub.f-Q.sup.2-SiX.sub.3-xR.sup.2.sub.x II
wherein: R.sup.2.sub.f is a perfluorinated group optionally
containing one or more heteroatoms (for example, oxygen atoms); the
connecting group Q.sup.2 is a divalent alkylene group, arylene
group, or mixture thereof, containing one or more heteroatoms
(e.g., oxygen, nitrogen, or sulfur), or functional groups (e.g.,
carbonyl, amido, or sulfonamido), and containing about 2 to about
16 carbon atoms (preferably, about 3 to about 10 carbon atoms);
R.sup.2 is a lower alkyl group (e.g., a C.sub.1-4 alkyl group,
preferably, a methyl group); X is a halogen (for example, a
chlorine atom), a lower alkoxy group (e.g., a C.sub.1-4 alkoxy
group, preferably, a methoxy or ethoxy group), or an acyloxy group
(e.g., OC(O)R.sup.3, wherein R.sup.3 is a C.sub.1-4 alkyl group);
and x is 0 or 1. For certain embodiments, preferably x is 0. For
certain of these embodiments, each X group is a lower alkoxy group.
For certain of these embodiments, X is methoxy or ethoxy.
Alternatively, the X groups include at least one acyloxy or halide
group. For certain of these embodiments, each X is a halide, and
for certain of these embodiments, each X is chloride.
[0069] For certain embodiments of Formula II, the perfluorinated
group, R.sup.2.sub.f, can include linear, branched, or cyclic
structures that may be saturated or unsaturated. For certain of
these embodiments, R.sup.2.sub.f is a perfluoroalkyl group
(C.sub.nF.sub.2n+1), wherein n is about 3 to about 20, more
preferably, about 3 to about 12, and most preferably, about 3 to
about 8. The divalent Q.sup.2 group can include linear, branched,
or cyclic structures, that may be saturated or unsaturated. For
certain of these embodiments, the divalent Q.sup.2 group is a
linear group containing heteroatoms or functional groups, for
example, as described above.
[0070] Typically, suitable fluorinated silanes include a mixture of
isomers (e.g., a mixture of compounds containing linear and
branched perfluoroalkyl groups). Mixtures of perfluoroalkyl silanes
exhibiting different values of n can also be used.
[0071] For certain embodiments, the perfluoroalkyl silane includes
any one or any combination of the following:
C.sub.3F.sub.7CH.sub.2OCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3;
C.sub.7F.sub.15CH.sub.2OCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3;
C.sub.7F.sub.15CH.sub.2OCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.2CH.sub.3).sub-
.3;
C.sub.7F.sub.15CH.sub.2OCH.sub.2CH.sub.2CH.sub.2Si(CH.sub.3)(OCH.sub.3-
).sub.2;
C.sub.7F.sub.15CH.sub.2OCH.sub.2CH.sub.2CH.sub.2SiCl.sub.3;
C.sub.7F.sub.15CH.sub.2OCH.sub.2CH.sub.2CH.sub.2Si(CH.sub.3)Cl.sub.2;
C.sub.7F.sub.5CH.sub.2OCH.sub.2CH.sub.2CH.sub.2SiCl(OCH.sub.3).sub.2;
C.sub.7F.sub.15CH.sub.2OCH.sub.2CH.sub.2CH.sub.2SiCl.sub.2(OC.sub.2H.sub.-
5);
C.sub.7F.sub.15C(O)NHCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3;
CF.sub.3(CF.sub.2CF(CF.sub.3)).sub.3CF.sub.2C(O)NHCH.sub.2CH.sub.2CH.sub.-
2Si(OCH.sub.2CH.sub.3).sub.3;
C.sub.8F.sub.17SO.sub.2N(CH.sub.2CH.sub.3)CH.sub.2CH.sub.2CH.sub.2Si(OCH.-
sub.3).sub.3;
C.sub.8F.sub.17SO.sub.2N(CH.sub.2CH.sub.3)CH.sub.2CH.sub.2CH.sub.2Si(OCH.-
sub.2CH.sub.3).sub.3;
C.sub.4F.sub.9SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).su-
b.3; C.sub.8F.sub.17CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3;
C.sub.6F.sub.13CH.sub.2CH.sub.2Si(OCH.sub.2CH.sub.3).sub.3;
C.sub.8F.sub.17CH.sub.2CH.sub.2Si(OCH.sub.2CH.sub.3).sub.3;
C.sub.8F.sub.17SO.sub.2N(CH.sub.2CH.sub.3)CH.sub.2CH.sub.2CH.sub.2SiCl.su-
b.3;
C.sub.8F.sub.17SO.sub.2N(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2Si(CH.sub.3-
)Cl.sub.2; and
C.sub.8F.sub.17CH.sub.2OCH.sub.2CH.sub.2CH.sub.2Si(OAc).sub.3.
[0072] Methods of making perfluoroalkyl silanes of the Formula II
are known. See, for example, U.S. Pat. No. 5,274,159 (Pellerite et
al.).
[0073] In another embodiment, the at least partially fluorinated
composition comprising at least one silane group is a fluorinated
oligomeric silane of the Formula III:
A-M.sup.f.sub.nM.sup.h.sub.mM.sup.a.sub.r-G III
[0074] wherein A represents hydrogen or the residue of an
initiating species (i.e., an organic compound having a radical and
that derives from the decomposition of a free radical initiator or
that derives from a chain transfer agent);
[0075] M.sup.f represents units derived from one or more
fluorinated monomers;
[0076] M.sup.h represents units derived from one or more
non-fluorinated monomers;
[0077] M.sup.a represents units having a silyl group represented by
the formula SiY''.sub.3
[0078] wherein each Y'' independently represents an alkyl group, an
aryl group, or a hydrolyzable group as defined above; and
[0079] G is a monovalent organic group comprising the residue of a
chain transfer agent, and having the formula:
--S-Q''-SiY.sub.3;
[0080] wherein Q'' is an organic divalent linking group as defined
below, and
[0081] each Y is independently a hydrolyzable group according to
any one of the above definitions of Y.
[0082] The total number of units represented by the sum of n, m,
and r is generally at least 2 and preferably at least 3 so as to
render the compound oligomeric. The value of n in the fluorinated
oligomeric silane is between 1 and 100 and preferably between 1 and
20. The values of m and r are between 0 and 100 and preferably
between 0 and 20. According to a preferred embodiment, the value of
m is less than that of n and n+m+r is at least 2.
[0083] The fluorinated oligomeric silanes typically have an number
average molecular weight between 400 and 100000, preferably between
600 and 20000, more preferably between 1000 and 10000. The
fluorinated oligomeric silanes preferably contains at least mole %
(based on total moles of units M.sup.f, M.sup.h, and M.sup.a) of
hydrolysable groups. When the units M.sup.h and/or M.sup.a are
present the units M.sup.f, M.sup.h, and/or M.sup.a may be randomly
distributed.
[0084] It will further be appreciated by one skilled in the art
that the preparation of fluorinated oligomeric silanes useful in
the present invention results in a mixture of compounds and
accordingly, general Formula III should be understood as
representing a mixture of compounds whereby the indices n, m and r
in Formula III represent the molar amounts of the corresponding
unit in such mixture. Accordingly, it will be clear that n, m and r
can be fractional values.
[0085] The units M.sup.f.sub.n of the fluorinated oligomeric silane
are derived from fluorinated monomers, preferably fluorochemical
acrylates and methacrylates.
[0086] Examples of fluorinated monomers for the preparation of the
fluorinated oligomeric silane include those that can be represented
by general formula:
R.sup.3.sub.f-Q''-E
wherein R.sup.3.sub.f represents a partially or fully fluorinated
aliphatic group having at least 3 carbon atoms or a fluorinated
polyether group, Q'' is a bond or an organic divalent linking
group, and E represents an ethylenically unsaturated group. The
ethylenically unsaturated group E can be fluorinated or
non-fluorinated.
[0087] The partially or fully fluorinated aliphatic group,
R.sup.3.sub.f, in the fluorochemical monomer can be a fluorinated,
preferably saturated, non-polar, monovalent aliphatic radical. It
can be straight chain, branched chain, or cyclic or combinations
thereof. It can contain heteroatoms such as oxygen, divalent or
hexavalent sulfur, or nitrogen. R.sup.3.sub.f is preferably a
fully-fluorinated radical, but hydrogen or chlorine atoms may be
present if not more than one atom of either is present for every
two carbon atoms. The R.sup.3.sub.f group has at least 2 and up to
18 carbon atoms, preferably 3 to 14, more preferably 4 to 10,
especially 4. The terminal portion of the R.sup.3.sub.f group is a
perfluorinated moiety, which will preferably contain at least 7
fluorine atoms, e.g., CF.sub.3CF.sub.2CF.sub.2-- and
(CF.sub.3).sub.2CF--. The preferred R.sup.3.sub.f groups are fully
or substantially fluorinated and are preferably those
perfluoroalkyl groups of the formula C.sub.nF.sub.2n+1-- where n is
3 to 18, particularly 4 to 10. Compounds wherein the R.sup.3.sub.f
group is a C.sub.4F.sub.9-- are generally more environmentally
friendly than compounds where the R.sup.3.sub.f group consists of a
perfluorinated group with more carbon atoms.
[0088] The R.sup.3.sub.f group can also be a perfluoropolyether
group, which can be include linear, branched, and/or cyclic
structures, that may be saturated or unsaturated, and substituted
with one or more oxygen atoms. For certain embodiments,
R.sup.3.sub.f includes perfluorinated repeating units selected from
the group consisting of --(C.sub.nF.sub.2n)--,
--(C.sub.nF.sub.2nO)--, --(CF(Z))--, --(CF(Z)O)--,
--(CF(Z)C.sub.nF.sub.2nO)--, --(C.sub.nF.sub.2nCF(Z)O)--,
--(CF.sub.2CF(Z)O)--, and combinations thereof. For certain of
these embodiments, Z is a perfluoroalkyl group, an
oxygen-containing perfluoroalkyl group, a perfluoroalkoxy group, or
an oxygen-substituted perfluoroalkoxy group, each of which can be
linear, branched, or cyclic, and have 1 to 9 carbon atoms and up to
4 oxygen atoms when oxygen-containing or oxygen-substituted. For
certain of these embodiments, R.sup.3.sub.f is terminated with a
group selected from the group consisting of C.sub.nF.sub.2n+1--,
C.sub.nF.sub.2n+1O--, and X'C.sub.nF.sub.2nO--, wherein X' is a
hydrogen or chlorine atom. For certain of these embodiments, the
terminal group is C.sub.nF.sub.2n+1-- or C.sub.nF.sub.2n+1O--. In
these repeating units or terminal groups, n is an integer of 1 or
more. For certain embodiments, n is an integer from 1 to 12, 1 to
6, or preferably 1 to 4. For certain of these embodiments, the
approximate average structure of R.sup.3.sub.f is
C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.pCF(CF.sub.3)-- or
CF.sub.3O(C.sub.2F.sub.4O).sub.pCF.sub.2--, wherein the average
value of p is 1 to about 50. As synthesized, these materials
typically include a mixture of polymers. The approximate average
structure is the approximate average of the mixture of
polymers.
[0089] The linking group Q'' links the fluoroaliphatic or the
fluorinated polyether group R.sup.3.sub.f to the free radical
polymerizable group E, and is a generally non-fluorinated organic
linking groups. The linking group can be a chemical bond, but
preferably contains from 1 to about 20 carbon atoms and may
optionally contain oxygen, nitrogen, or sulfur-containing groups or
a combination thereof. The linking group is preferably free of
functional groups that substantially interfere with free-radical
oligomerization (e.g., polymerizable olefinic double bonds, thiols,
and other such functionality known to those skilled in the art).
Examples of suitable organic divalent linking groups, Q'', include,
for example, --C(O)Q.sup.a-R.sup.5-Q.sup.b-C(O)--,
--C(O)O--CH.sub.2--CH(OH)--R.sup.5-Q.sup.a-C(O)--,
-L.sup.1-Q.sup.a-C(O)NH-L.sup.2-, --R.sup.5-Q.sup.a-C(O)--,
--C(O)Q.sup.a-R.sup.5--, --R.sup.5--,
--C(O)Q.sup.a-R.sup.5-Q.sup.a-, --S(O).sub.2NR--R.sup.5-Q.sup.a-,
--S(O).sub.2NR--R.sup.5--, and
--S(O).sub.2NR--R.sup.5-Q.sup.a-C(O)--, wherein Q.sup.a and Q.sup.b
independently represent O or NR, R is hydrogen or C.sub.1-4 alkyl,
R.sup.5 represents a linear, cyclic or branched alkylene group that
may be interrupted by one or more heteroatoms such as O or N,
L.sup.1 and L.sup.2 each independently represent a non-fluorinated
organic divalent linking group including an alkylene group, a
carbonyl group, a carboxy amido alkylene group and/or a carboxy
alkylene group. Preferred linking groups, Q'', include
--S(O).sub.2N(R)--(CH.sub.2).sub.d--OC(O)-- and
--(CH.sub.2).sub.d--OC(O)--, where d is an integer from 1 to 20,
preferably from 1 to 4.
[0090] Fluorochemical monomers R.sup.3.sub.f-Q''-E as described
above and methods for the preparation thereof are known and
disclosed, e.g., in U.S. Pat. No. 2,803,615 (Ahlbrecht et al.).
Examples of such compounds include general classes of
fluorochemical acrylates, methacrylates, vinyl ethers, and allyl
compounds containing fluorinated sulfonamido groups, acrylates or
methacrylates derived from fluorochemical telomer alcohols,
acrylates or methacrylates derived from fluorochemical carboxylic
acids, and perfluoroalkyl acrylates or methacrylates as disclosed
in European Patent No. 0 526 976, published Jan. 15, 1997.
[0091] Perfluoropolyether acrylates or methacrylates are described
in U.S. Pat. No. 4,085,137 (Mitsch et al.).
[0092] Preferred examples of fluorinated monomers include:
CF.sub.3(CF.sub.2).sub.2CH.sub.2OC(O)CH.dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.2CH.sub.2OC(O)C(CH.sub.3).dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.3CH.sub.2OC(O)C(CH.sub.3).dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.3CH.sub.2OC(O)CH.dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.3S(O).sub.2N(R.sup.a)--(CH.sub.2).sub.2--OC(O)CH.d-
bd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.3S(O).sub.2N(R.sup.a)--(CH.sub.2).sub.2--OC(O)C(CH-
.sub.3).dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.3S(O).sub.2N(CH.sub.3)--(CH.sub.2).sub.2--OC(O)C(C-
H.sub.3).dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.3S(O).sub.2N(CH.sub.3)--(CH.sub.2).sub.2--OC(O)CH.-
dbd.CH.sub.2,
CF.sub.3CF.sub.2(CF.sub.2CF.sub.2).sub.2-8(CH.sub.2).sub.2OC(O)CH.dbd.CH.-
sub.2,
CF.sub.3(CF.sub.2).sub.7(CH.sub.2).sub.2OC(O)CH.dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.7(CH.sub.2).sub.2OC(O)C(CH.sub.3).dbd.CH.sub.2,
CF.sub.3(CF.sub.2).sub.7S(O).sub.2N(R.sup.a)--(CH.sub.2).sub.2--OC(O)CH.d-
bd.CH.sub.2 CF.sub.3
(CF.sub.2).sub.7S(O).sub.2N(R.sup.a)--(CH.sub.2).sub.2OC(O)C(CH.sub.3).db-
d.CH.sub.2,
CF.sub.3(CF.sub.2).sub.7CH.sub.2CH.sub.2S(O).sub.2N(CH.sub.3)--(CH.sub.2)-
.sub.2OC(O)C(CH.sub.3).dbd.CH.sub.2
CF.sub.3O(CF.sub.2CF.sub.2).sub.uCH.sub.2OC(O)CH.dbd.CH.sub.2,
CF.sub.3O(CF.sub.2CF.sub.2).sub.uCH.sub.2OC(O)C(CH.sub.3).dbd.CH.sub.2,
C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.uCF(CF.sub.3)CH.sub.2OC(O)CH.d-
bd.CH.sub.2,
C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.uCF(CF.sub.3)CH.sub.2OC(O)C(CH-
.sub.3).dbd.CH.sub.2,
C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.uCF(CF.sub.3)CONHCH2CH.sub.2OC-
(O)C(CH.sub.3).dbd.CH.sub.2, and
C.sub.3F.sub.7O(CF(CF.sub.3)CF.sub.2O).sub.uCF(CF.sub.3)CONHCH2CH.sub.2OC-
ONH--CH2CH2-OC(O)C(CH.sub.3).dbd.CH.sub.2;
[0093] wherein R.sup.a represents methyl, ethyl or n-butyl, and u
is about 1 to 50.
[0094] The units M.sup.h (when present) of the fluorinated
oligomeric silane are generally derived from a non-fluorinated
monomer, preferably a monomer consisting of a polymerizable group
and a hydrocarbon moiety. Hydrocarbon group containing monomers are
well known and generally commercially available. Examples of
hydrocarbon containing monomers include those according to
formula:
R.sup.h-Q'''-E
wherein R.sup.h is a hydrocarbon group, optionally containing one
or more oxyalkylene groups or one or more reactive groups, such as
hydroxy groups, amino groups, epoxy groups, and halogen atoms such
as chlorine and bromine, Q''' is a chemical bond or a divalent
linking group as defined above for Q'', and E is an ethylenically
unsaturated group as defined above. The hydrocarbon group is
preferably selected from the group consisting of a linear, branched
or cyclic alkyl group, an arylalkylene group, an alkylarylene
group, and an aryl group. Preferred hydrocarbon groups contain from
4 to 30 carbon atoms.
[0095] Examples of non-fluorinated monomers from which the units
M.sup.h can be derived include general classes of ethylenic
compounds capable of free-radical polymerization, such as allyl
esters such as allyl acetate and allyl heptanoate; alkyl vinyl
ethers or alkyl allyl ethers, such as cetyl vinyl ether, dodecyl
vinyl ether, 2-chloroethyl vinyl ether, ethyl vinyl ether;
anhydrides and esters of unsaturated acids such as acrylic acid,
methacrylic acid, alpha-chloro acrylic acid, crotonic acid, maleic
acid, fumaric acid, and itaconic acid; vinyl, allyl, methyl, butyl,
isobutyl, hexyl, heptyl, 2-ethylhexyl, cyclohexyl, lauryl, stearyl,
isobornyl or alkoxyethyl acrylates and methacrylates; alpha-beta
unsaturated nitriles such as acrylonitrile, methacrylonitrile,
2-chloroacrylonitrile, 2-cyanoethyl acrylate, alkyl cyanoacrylates;
allyl glycolate, acrylamide, methacrylamide, n-diisopropyl
acrylamide, diacetoneacrylamide, N,N-diethylaminoethylmethacrylate,
N-t-butylamino ethyl methacrylate; styrene and its derivatives such
as vinyltoluene, alpha-methylstyrene, alpha-cyanomethyl styrene;
lower olefinic hydrocarbons which can contain halogen such as
ethylene, propylene, isobutene, 3-chloro-1-isobutene, butadiene,
isoprene, chloro and dichlorobutadiene, 2,5-dimethyl-1,5-hexadiene,
and allyl or vinyl halides such as vinyl and vinylidene chloride.
Preferred non-fluorinated monomers include hydrocarbon group
containing monomers such as those selected from octadecyl
methacrylate, lauryl methacrylate, butyl acrylate,
N-methylol-acrylamide, isobutyl methacrylate, ethylhexyl acrylate
and ethylhexyl methacrylate; and vinylchloride and vinylidene
chloride.
[0096] The fluorinated oligomeric silane useful in the invention
generally further includes units M.sup.a that have a silyl group
with hydrolyzable groups at the terminus of the units derived from
one or more non-fluorinated monomers as defined above. Examples of
units M.sup.a include those that correspond to the general
formula:
E-Z--SiY''.sub.3
wherein E is an ethylenically unsaturated group as defined above,
Y'' is as defined above, and Z is a chemical bond or a divalent
linking group containing 1 to 20 carbon atoms and optionally
containing oxygen, nitrogen, or sulfur-containing groups or a
combination thereof. Z is preferably free of functional groups that
substantially interfere with free-radical oligomerization (e.g.,
polymerizable olefinic double bonds, thiols, and other such
functional groups known to those skilled in the art). Examples of
suitable linking groups Z include straight chain, branched chain,
or cyclic alkylene, arylene, arylalkylene, oxyalkylene,
carbonyloxyalkylene, oxycarboxyalkylene, carboxyamidoalkylene,
oxycarbonylaminoalkylene, ureylenealkylene, and combinations
thereof. For certain embodiments, Z is selected from the group
consisting of alkylene, oxyalkylene, carbonyloxyalkylene, and the
formula:
-Q.sup.3-T-C(O)NH-Q.sup.4-
wherein Q.sup.3 and Q.sup.4 are independently an organic divalent
linking group selected from the group consisting of alkylene,
arylene, oxyalkylene, carbonyloxyalkylene, oxycarboxyalkylene,
carboxyamidoalkylene, oxycarbonylaminoalkylene, and
ureylenealkylene; T is O or NR.sup.6 wherein R.sup.6 is hydrogen,
C.sub.1-4 alkyl, or aryl. For certain of these embodiments, Q.sup.4
is alkylene or arylene. Typical examples of such monomers include
vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane,
and alkoxysilane functionalized acrylates or methacrylates, such as
trimethoxysilylpropyl methacrylate and the like.
[0097] The fluorinated oligomeric silane is conveniently prepared
through a free radical polymerization of a fluorinated monomer with
optionally a non-fluorinated monomer and/or a monomer containing
the silyl group in the presence of a chain transfer agent. A free
radical initiator is generally used to initiate the polymerization
or oligomerization reaction. Commonly known free-radical initiators
can be used and examples thereof include azo compounds, such as
azobisisobutyronitrile (AIBN), azo-2-cyanovaleric acid and the
like, hydroperoxides such as cumene, t-butyl and t-amyl
hydroperoxide, dialkyl peroxides such as di-t-butyl and
dicumylperoxide, peroxyesters such as t-butylperbenzoate and
di-t-butylperoxy phthalate, diacylperoxides such as benzoyl
peroxide and lauroyl peroxide.
[0098] The oligomerization reaction can be carried out in any
solvent suitable for organic free-radical reactions. The reactants
can be present in the solvent at any suitable concentration (e.g.,
from about 5 percent to about 90 percent by weight based on the
total weight of the reaction mixture). Examples of suitable
solvents include aliphatic and alicyclic hydrocarbons (e.g.,
hexane, heptane, cyclohexane), aromatic solvents (e.g., benzene,
toluene, xylene), ethers (e.g., diethylether, glyme, diglyme,
diisopropyl ether), esters (e.g., ethyl acetate, butyl acetate),
alcohols (e.g., ethanol, isopropyl alcohol), ketones (e.g.,
acetone, methylethyl ketone, methyl isobutyl ketone), sulfoxides
(e.g., dimethyl sulfoxide), amides (e.g., N,N-dimethylformamide,
N,N-dimethylacetamide), halogenated solvents such as
methylchloroform, 1,1,2-trichloro-1,2,2-trifluoroethane,
trichloroethylene, .alpha.,.alpha.,.alpha.-trifluorotoluene, and
the like, and mixtures thereof.
[0099] The oligomerization reaction can be carried out at any
temperature suitable for conducting an organic free-radical
reaction. Particular temperature and solvents for use can be easily
selected by those skilled in the art based on considerations such
as the solubility of reagents, the temperature required for the use
of a particular initiator, molecular weight desired and the like.
While it is not practical to enumerate a particular temperature
suitable for all initiators and all solvents, generally suitable
temperatures are between about 30.degree. C. and about 200.degree.
C., preferably between 50.degree. C. and 100.degree. C.
[0100] The fluorinated oligomeric silane is typically prepared in
the presence of a chain transfer agent. Suitable chain transfer
agents may include a hydroxy-, amino-, mercapto or halogen group.
The chain transfer agent may include two or more of such hydroxy,
amino-, mercapto or halogen groups. Typical chain transfer agents
useful in the preparation of the fluorinated oligomeric silane
include those selected from 2-mercaptoethanol,
3-mercapto-2-butanol, 3-mercapto-2-propanol, 3-mercapto-1-propanol,
3-mercapto-1,2-propanediol, 2-mercaptoethylamine,
di(2-mercaptoethyl)sulfide, octylmercaptane, and
dodecylmercaptane.
[0101] In a preferred embodiment, a chain transfer agent containing
a silyl group having hydrolyzable groups is used in the
oligomerization to produce the fluorinated oligomeric silane. Such
chain transfer agents are of the following formula:
HS-Q.sup.5-SiY.sub.3
wherein Q.sup.5 represents an organic divalent linking group such
as for example a straight chain, branched chain or cyclic alkylene,
arylene or arylalkylene; and each Y is independently a hydrolyzable
group as defined above. Q.sup.5 is preferably C.sub.1-20
alkylene.
[0102] Alternatively, a functionalized chain transfer agent or
functionalized co-monomer can be used in the oligomerization. The
functional group introduced by the functionalized chain transfer
agent or functionalized co-monomer can then be reacted with a silyl
group containing reagent subsequent to the oligomerization to
introduce a silyl group having hydrolyzable groups.
[0103] A single chain transfer agent or a mixture of different
chain transfer agents may be used. For certain embodiments,
2-mercaptoethanol, octylmercaptane, and
3-mercaptopropyltrimethoxysilane are preferred chain transfer
agents. A chain transfer agent is typically present in an amount
sufficient to control the number of polymerized monomer units in
the oligomer and to obtain the desired molecular weight of the
oligomeric fluorochemical silane.
[0104] The fluorinated oligomeric silane can be prepared by
oligomerizing a fluorinated monomer and optional non-fluorinated
monomer with a monomer E-Z--SiY''.sub.3, wherein at least one Y''
represents a hydrolysable group, in the presence of a chain
transfer agent which may optionally also contain a silyl group such
as, for example, HS-Q.sup.5-SiY.sub.3.
[0105] As a variation to the above method the oligomerization may
be carried out without the use of the silyl group containing
monomer but with a chain transfer agent containing the silyl
group.
[0106] In another embodiment, the at least partially fluorinated
composition comprising at least one silane group is a swallow-tail
silane of the Formula IV:
R.sup.4.sub.fS(O).sub.2--N(R.sup.7)--(C.sub.nH.sub.2n)--CH(Z.sup.1)--(C.-
sub.mH.sub.2m)--N(R.sup.8)--S(O).sub.2R.sup.4.sub.f IV
wherein each R.sup.4.sub.f is independently C.sub.pF.sub.2p+1,
wherein p is 1 to 8; R.sup.7 is C.sub.1-4 alkyl or aryl; m and n
are both integers from 1 to 20; Z.sup.1 is hydrogen or a group of
the formula --(CC.sub.m'H.sub.2m')--X.sup.1-Q.sup.5-Si(Y).sub.3
wherein m' is 0 to 4, X.sup.1 is O, S, or NH, Q.sup.5 is
--C(O)NH--(CH.sub.2).sub.n'-- or --(CH.sub.2).sub.n'--, n' is an
integer of 1 to 20, and Y is a hydrolysable group; and R.sup.8 is
R.sup.7 or a group of the formula --(CH.sub.2).sub.n'--Si(Y).sub.3,
with the proviso that when Z.sup.1 is hydrogen, then R.sup.8 is a
group of the formula --(CH.sub.2).sub.n'--Si(Y).sub.3.
[0107] Each R.sup.4.sub.f may be the same or different, and each
contains 1-8 carbon atoms, preferably 2-5 carbon atoms, more
preferably 4 carbon atoms.
[0108] For certain embodiments, including any one of the above
embodiments of Formula IV, m is an integer from 1 to 6, and n is an
integer from 1 to 6.
[0109] For certain embodiments, including any one of the above
embodiments of Formula IV, R.sup.7 is C.sub.1-4 alkyl. For certain
of these embodiments, C.sub.1-4 alkyl is methyl or ethyl.
[0110] For certain embodiments, including any one of the above
embodiments of Formula IV, R.sup.8 is C.sub.1-4 alkyl. For certain
of these embodiments, C.sub.1-4 alkyl is methyl or ethyl.
[0111] For certain embodiments, including any one of the above
embodiments of Formula N except where R.sup.7 is C.sub.1-4 alkyl,
R.sup.7 is aryl.
[0112] For certain embodiments, including any one of the above
embodiments of Formula IV except where R.sup.8 is C.sub.1-4 alkyl,
R.sup.8 is aryl.
[0113] For certain embodiments where R.sup.7 and/or R.sup.8 is
aryl, aryl is phenyl which is unsubstituted or substituted by one
or up to five substituents independently selected from the group
consisting of C.sub.1-4 alkyl, C.sub.1-4 alkoxy, halogen (e.g.
fluoro, chloro, bromo, and/or iodo groups), hydroxy, amino, and
nitro. When substituents are present, halogen and C.sub.1-4 alkyl
substituents are preferred.
[0114] For certain embodiments, including any one of the above
embodiments of Formula N, n' is an integer from 1 to 10, and in one
embodiment n' is 3.
[0115] For certain embodiments, including any one of the above
embodiments of Formula IV, Y is defined as in any one of the above
definitions of Y. For certain of these embodiments, Y is
--OC.sub.1-4 alkyl, --OC(O)CH.sub.3, or Cl.
[0116] For certain embodiments, swallow-tail silanes of the Formula
IV include, but are not limited to
[C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2].sub.2CHOCH.sub.2CH.sub.2CH.-
sub.2Si(OCH.sub.3).sub.3,
[C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2].sub.2CHOC(O)NHCH.sub.2CH.su-
b.2CH.sub.2Si(OCH.sub.3).sub.3, and
C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2N(S(O).sub.2C.-
sub.4F.sub.9)CH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3.
[0117] The swallow-tail silane of the Formula N may be prepared by
known methods. For example,
[C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2].sub.2CHOH may be made
by reacting two moles of C.sub.4F.sub.9S(O).sub.2NHCH.sub.3 with
either 1,3-dichloro-2-propanol or epichlorohydrin in the presence
of a base.
[C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2].sub.2CHOCH.sub.2CH.sub.2CH.-
sub.2Si(OCH.sub.3).sub.3 can be made from
[C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2].sub.2CHOH by
alkylation with ClCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3 or by
alkylation with allyl chloride, followed by hydrosilation with
HSiCl.sub.3 and methanolysis. Reaction of
[C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2].sub.2CHOH with
OCNCH.sub.2CH.sub.2CH.sub.2Si(OCH.sub.3).sub.3 yields
[C.sub.4F.sub.9S(O).sub.2N(CH.sub.3)CH.sub.2].sub.2CHOC(O)NHCH.sub.2CH.su-
b.2CH.sub.2Si(OCH.sub.3).sub.3.
[0118] In another embodiment, the at least partially fluorinated
composition comprising at least one silane group is a
hexafluoropropyleneoxide (HFPO) quat silane. For example, quat
silanes with general Formula V or VI can be used:
##STR00002##
wherein b and c is each independently an integer of 1 to 3; R.sub.f
is a perfluorinated ether group; A is a linking group having the
formula --C.sub.dH.sub.2dZC.sub.gH.sub.2g--, wherein d and g are
independently integers from 0 to 10 and Z is selected from the
group consisting of a covalent bond, a carbonyl group, a sulfonyl
group, a carboxamido group, a sulfonamido group, an iminocarbonyl
group, an iminosulfonyl group, an oxycarbonyl group, a urea group,
a urethane group, a carbonate group, and a carbonyloxy group; Y is
a bridging group having 1 to 10 carbon atoms, a valency of 2 to 6,
and comprising at least one of an alkylene group or an arylene
group; Q is a connecting group having 1 to 10 carbon atoms, a
valency of 2 to 6, and comprising at least one of an alkylene group
or an arylene group; R.sup.1 and R.sup.2 are independently selected
from the group consisting of a hydrogen atom, an alkyl group, an
aryl group, and an aralkyl group; each R.sup.3 is independently
selected from the group consisting of hydroxy groups, alkoxy
groups, acyl groups, acyloxy groups, halo groups, and polyether
groups; and X.sup.- is a counter ion selected from the group
consisting of inorganic anions organic anions, and combinations
thereof.
##STR00003##
wherein R.sub.f has the structure
--CF(CF.sub.3)(OCF.sub.2CF(CF.sub.3)).sub.mOCF.sub.2CF.sub.2CF.sub.2CF.su-
b.2O(CF(CF.sub.3)CF.sub.2O).sub.nCF(CF.sub.3)--, wherein m is an
integer of 1 to 12 and n is an integer of 2 to 10; c is an integer
from about 1 to about 3; A is a linking group having the formula
--C.sub.dH.sub.2dZC.sub.gH.sub.2g--, wherein d and g are
independently integers from about 0 to about 10 and Z is selected
from the group consisting of a covalent bond, a carbonyl group, a
sulfonyl group, a carboxamido group, a sulfonamido group, an
iminocarbonyl group, an iminosulfonyl group, an oxycarbonyl group,
a urea group, a urethane group, a carbonate group, and a
carbonyloxy group; Y is a bridging group comprising an alkylene
group having about 1 to about 6 carbon atoms; Q is a connecting
group comprising an alkylene group having about 1 to about 6 carbon
atoms; R.sup.1 and R.sup.2 are independently alkyl groups having
about 1 to about 4 carbon atoms; each R.sup.3 is independently
selected from the group consisting of hydroxy groups, methoxy
groups, ethoxy groups, acetoxy groups, chloro groups, and polyether
groups; and X.sup.- is a counter ion selected from the group
consisting of a halide, sulfate, phosphate, an alkyl sulfonate, an
aryl sulfonate, an alkyl phosphonate, an aryl phosphonate, a
fluorinated alkyl sulfonate, a fluorinated aryl sulfonate, a
fluorinated alkyl sulfonimide, a fluorinated alkyl methide, and
combinations thereof.
[0119] In other embodiments, particularly when the tie layer
comprises diamond-like glass, the at least partially fluorinated
composition comprising at least one silane group comprises a
composition comprising:
[0120] (a) a first polyfluoropolyether silane of the Formula
VIIIa:
CF.sub.3CF.sub.2CF.sub.2O(CF(CF.sub.3)CF.sub.2O).sub.pCF(CF.sub.3)--C(O)-
NH(CH.sub.2).sub.3Si(Y).sub.3 VIIa [0121] wherein each Y is
independently a hydrolyzable group and wherein p is 3 to 50;
and
[0122] (b) a second polyfluoropolyether silane of the Formula
IIXa:
(Y).sub.3Si(CH.sub.2).sub.3NHC(O)--CF.sub.2O(CF.sub.2O).sub.m(C.sub.2F.s-
ub.4O).sub.qCF.sub.2--C(O)NH(CH.sub.2).sub.3Si(Y').sub.3 IIXa
[0123] wherein each Y' is independently a hydrolyzable group and
wherein m is 1 to 50 and q is 3 to 40. Hydrolyzable groups, Y and
Y' of Formula VIIa and IIXa, respectively may be the same or
different (within a compound of a Formula and between compounds of
Formula VIIIa and IIXa). Favorably such groups are capable of
hydrolyzing, for example, in the presence of water, optionally
under acidic or basic conditions, producing groups capable of
undergoing a condensation reaction, for example silanol groups. For
example, methoxy and ethoxy groups form essentially immediately "in
situ" (e.g. in the presence of water, optionally under acidic or
basic conditions) hydroxy groups, thus producing silanol groups.
Desirably, each Y of Formula VIIa and each Y' of Formula IIXa are
independently groups selected from the group consisting of
hydrogen, halogen, alkoxy, acyloxy, aryloxy, and polyalkyleneoxy,
more desirably each Y of Formula VIIIa and each Y' of Formula IIXa
are independently groups selected from the group consisting of
alkoxy, acyloxy, aryloxy, and polyalkyleneoxy, even more desirably
each Y of Formula VIIa and each Y' of Formula IIXa are
independently groups selected from the group consisting of alkoxy,
acyloxy and aryloxy, and most desirably each Y of Formula VIIa and
each Y' of Formula IIXa are independently alkoxy groups, in
particular lower (C1-C4) alkoxy groups, more particularly methoxy
and/or ethoxy groups.
[0124] Similarly, the at least partially fluorinated composition
comprising at least one silane group can comprises a composition
comprising:
[0125] (a) a first polyfluoropolyether silane entity of the Formula
VIIb:
CF.sub.3CF.sub.2CF.sub.2O(CF(CF.sub.3)CF.sub.2O).sub.pCF(CF.sub.3)--C(O)-
NH(CH.sub.2).sub.3Si(O--).sub.3 VIIb [0126] wherein p is 3 to 50;
and
[0127] (b) a second polyfluoropolyether silane entity of the
Formula IIXb:
(--O).sub.3Si(CH.sub.2).sub.3NHC(O)--CF.sub.2O(CF.sub.2O).sub.m(C.sub.2F-
.sub.4O).sub.gCF.sub.2--C(O)NH(CH.sub.2).sub.3Si(O--).sub.3 IIXb
[0128] wherein m is 1 to 50 and q is 3 to 40.
[0129] Compounds in accordance with Formula VIIIa and IIXa as
described above can be synthesized using standard techniques. For
example, commercially available or readily synthesized
polyfluoropolyether esters (or functional derivatives thereof) can
be combined with 3-aminopropylalkoxysilane, and methods described
in U.S. Pat. Nos. 3,250,808 (Moore), 3,646,085 (Barlett), 3,810,874
(Mitsch et al.) and CA Patent No. 725747 (Moore) can be used to
prepare compounds in accordance with Formula VIIIa and IIXa.
[0130] For certain embodiments, the p in Formula VIIIa or VIIb is
from about 3 to about 20, in particular from about 4 to about 10.
For certain embodiments, for Formula IIXa or IIXb m+q or q is from
about 4 to about 24, in particular m and q are each about 9 to
about 12. For certain embodiments, the weight average molecular
weight of the polyfluoropolyether segment of the first
polyfluoropolyether silane of the Formula VIIIa or VIIb is about
900 or higher, in particular about 1000 or higher. For certain
embodiments, the weight average molecular weight of the
polyfluoropolyether segment of the second polyfluoropolyether
silane of the Formula IIXa or II b is about 1000 or higher, in
particular about 1800 or higher. Generally, the weight average
molecular weight of the polyfluoropolyether segment of the second
polyfluoropolyether silane of the Formula IIXa is desirably about
6000 at most, in particular about 4000 at most and/or the weight
average molecular weight of the polyfluoropolyether segment of the
first polyfluoropolyether silane of the Formula VIIIa is about 4000
at most, in particular about 2500 at most.
[0131] Polyfluoropolyether silanes typically include a distribution
of oligomers and/or polymers. Desirably, the amount of
polyfluoropolyether silane (in such a distribution) having a
polyfluoropolyether segment having a weight average molecular
weight less than 750 is not more than 10% by weight (more desirably
not more than 5% by weight, and even more desirably not more 1% by
weight and most desirably 0%) of total amount of
polyfluoropolyether silane in said distribution.
[0132] The above structures are approximate average structures
where p and m and q designate the number of randomly distributed
perfluorinated repeating units. Further, as mentioned above
polyfluoropolyether silanes described herein typically include a
distribution of oligomers and/or polymers, so p and/or m and/or q
may be non-integral and where the number is the approximate average
is over this distribution.
[0133] Certain favorable embodiments of the composition comprise
first and second polyfluoropolyether silane entities as described
above desirably having a weight percent ratio of the first to
second polyfluoropolyether silane entity (first polyfluoropolyether
silane entity:second fluoropolyether silane entity) equal to or
greater than 10:90, in particular equal to or greater than 20:80,
more particularly equal to or greater than 30:70, most particularly
equal to or greater than 40:60. Other desirable embodiments of the
composition comprise first and second polyfluoropolyether silane
entities as described above having the weight percent ratio of the
first to second polyfluoropolyether silane (first
polyfluoropolyether silane:second polyfluoropolyether silane) equal
to or less than 99:1, in particular equal to or less than 97:3,
most particularly equal to or less than 95:5.
[0134] For certain embodiments, including any one of the above
embodiments, the at least partially fluorinated composition
comprising at least one silane group further includes an organic
solvent.
[0135] For certain embodiments, including any one of the above
embodiments wherein the at least partially fluorinated composition
comprising at least one silane group is a polyfluoropolyether
silane, the polyfluoropolyether silane is applied as a composition
comprising the polyfluoropolyether silane and an organic
solvent.
[0136] The organic solvent or blend of organic solvents used must
be capable of dissolving at least about 0.01 percent by weight of
one or more silanes of the Formulas I through IV. For certain
embodiments, it is desirable that the solvent or mixture of
solvents have a solubility for water of at least about 0.1 percent
by weight, and for certain of these embodiments, a solubility for
acid of at least about 0.01 percent by weight.
[0137] Suitable organic solvents, or mixtures of solvents can be
selected from aliphatic alcohols, such as methanol, ethanol, and
isopropanol; ketones such as acetone and methyl ethyl ketone;
esters Such as ethyl acetate and methyl formate; ethers such as
diethyl ether, diisopropyl ether, methyl t-butyl ether and
dipropyleneglycol monomethylether (DPM); hydrocarbons solvents such
as alkanes, for example, heptane, decane, and paraffinic solvents;
fluorinated hydrocarbons such as perfluorohexane and
perfluorooctane; partially fluorinated hydrocarbons, such as
pentafluorobutane; hydrofluoroethers such as methyl perfluorobutyl
ether and ethyl perfluorobutyl ether.
[0138] For certain embodiments, including any one of the above
embodiments, the organic solvent is a fluorinated solvent, which
includes fluorinated hydrocarbons, partially fluorinated
hydrocarbons, and hydrofluoroethers. For certain of these
embodiments, the fluorinated solvent is a hydrofluoroether. For
certain of these embodiments, the hydrofluoroether is methyl
perfluorobutyl ether.
[0139] For certain embodiments, including any one of the above
embodiments except where the organic solvent is a fluorinated
solvent, the organic solvent is a lower alcohol. For certain of
these embodiments, the lower alcohol is selected from the group
consisting of methanol, ethanol, isopropanol, and mixtures thereof.
For certain of these embodiments, the lower alcohol is ethanol.
[0140] For certain embodiments, including any one of the above
embodiments where the organic solvent is a lower alcohol, the at
least partially fluorinated composition comprising at least one
silane group further comprises an acid. For certain of these
embodiments, the acid is selected from the group consisting of
acetic acid, citric acid, formic acid, triflic acid,
perfluorobutyric acid, sulfuric acid, and hydrochloric acid. For
certain of these embodiments, the acid is hydrochloric acid.
[0141] The at least partially fluorinated composition comprising at
least one silane group, including any one of the above embodiments,
can be applied to at least a portion of the surface of the layer
comprising the silicon, oxygen, and hydrogen using a variety of
coating methods. Such methods include but are not limited to
spraying, dipping, rolling, brushing, spreading, flow coating, and
vapor deposition.
[0142] Typically the at least partially fluorinated composition
comprising at least one silane group is a monolayer that is from
about 0.001 to about 1 micron thick; preferably from about 0.001 to
about 0.10 microns thick.
[0143] For certain embodiments, including any one of the above
embodiments, the at least partially fluorinated composition
comprising at least one silane group, in any one of its above
described embodiments, is applied by dipping at least a portion of
the substrate upon which the layer comprising the silicon, oxygen,
and hydrogen has been formed in the at least partially fluorinated
composition comprising at least one silane group.
[0144] Alternatively, for certain embodiments, including any one of
the above embodiments, the at least partially fluorinated
composition comprising at least one silane group, in any one of its
above described embodiments, is applied by spraying at least a
portion of the substrate upon which the layer comprising the
silicon, oxygen, and hydrogen has been formed with the at least
partially fluorinated composition comprising at least one silane
group.
[0145] For certain embodiments, including any one of the above
embodiments except where the at least partially fluorinated
composition comprising at least one silane group, is applied by
other means, the at least partially fluorinated composition
comprising at least one silane group, in any one of its above
described embodiments, is applied by chemical vapor deposition to
at least a portion of the substrate upon which the layer comprising
the silicon, oxygen, and hydrogen has been formed. For certain of
these embodiments, the at least partially fluorinated composition
comprising at least one silane group is a polyfluoropolyether
silane.
[0146] The conditions under which the at least partially
fluorinated composition comprising at least one silane group, for
example, the polyfluoropolyether silane is vaporized during
chemical vapor deposition may vary according to the structure and
molecular weight of the polyfluoropolyether silane. For certain
embodiments, the vaporizing may take place at pressures less than
about 1.3 Pa (about 0.01 torr), at pressures less than about 0.013
Pa (about 10.sup.-4 torr) or even about 0.0013 Pa to about 0.00013
Pa (about 10.sup.-5 torr to about 10.sup.-6 torr). For certain of
these embodiments, the vaporizing may take place at temperatures of
at least about 80.degree. C., at least about 100.degree. C., at
least about 200.degree. C., or at least about 300.degree. C.
Vaporizing may include imparting energy by, for example conductive
heating, convective heating, microwave radiation heating, and the
like.
[0147] The chemical vapor deposition method may reduce
opportunities for contamination of the surface of the substrate
through additional handling and exposure to the environment,
leading to correspondingly lower yield losses. Furthermore, as the
layer comprising silicon, oxygen, and hydrogen is formed by plasma
deposition, it can be more efficient to apply the at least
partially fluorinated composition comprising at least one silane
group, for example, the polyfluoropolyether silanes in the same
chamber or a connected vacuum chamber. Additionally, the
polyfluoropolyether silane coatings applied by chemical vapor
deposition may not need acid conditions and/or additional heating
for curing. Useful vacuum chambers and equipment are known in the
art. Examples include the Plasmatherm Model 3032 (available from
Plasmatherm, Kresson, N.J.) and the 900 DLS (available from Satis
Vacuum of America, Grove Port, Ohio).
[0148] In one embodiment, applying the polyfluoropolyether silane
by chemical vapor deposition comprises placing the
polyfluoropolyether silane and the substrate, having the layer
comprising silicon, oxygen, and hydrogen on at least a portion of
the surface of the substrate, into a chamber, decreasing the
pressure in the chamber, and heating the polyfluoropolyether
silane. The polyfluoropolyether silane is typically maintained in a
crucible, but in some embodiments, the silane is imbibed in a
porous matrix, such as a ceramic pellet, and the pellet heated in
the vacuum chamber.
[0149] The at least partially fluorinated composition comprising at
least one silane group, including any one of the above embodiments
of Formulas I, II, III, and/or IV, undergoes reaction with the
layer comprising the silicon, oxygen, and hydrogen on the substrate
surface, for example, with --SiOH groups, to form a durable
coating, through the formation of covalent bonds, including bonds
in Si--O--Si groups. For the preparation of a durable coating,
sufficient water should be present to cause hydrolysis of the
hydrolyzable groups described above so that condensation to form
Si--O--Si groups takes place, and thereby curing takes place. The
water can be present either in the coating composition or adsorbed
to the substrate surface, for example. Typically, sufficient water
is present for the preparation of a durable coating if the coating
method is carried out at room temperature in an atmosphere
containing water, for example, an atmosphere having a relative
humidity of about 30% to about 50%.
[0150] A substrate to be coated can typically be contacted with the
coating composition at room temperature (typically, about
15.degree. C. to about 30.degree. C., or about 20.degree. C. to
about 25.degree. C.). Alternatively, the coating composition can be
applied to substrates which are preheated at a temperature of, for
example, between 60.degree. C. and 150.degree. C. Following
application of the at least partially fluorinated composition
comprising at least one silane group, the treated substrate can be
dried and the resulting coating cured at ambient temperature, e.g.,
about 15.degree. C. to about 30.degree. C., or elevated temperature
(e.g., at about 40.degree. C. to about 300.degree. C.) and for a
time sufficient for the curing to take place.
[0151] For certain embodiments, including any one of the above
embodiments, the method of the invention further comprises the step
of subjecting the substrate to an elevated temperature after
applying the at least partially fluorinated composition comprising
at least one silane group.
[0152] For certain embodiments, including any one of the above
embodiments where the at least partially fluorinated composition
comprising at least one silane group is a polyfluoropolyether
silane, the method of the invention comprises the step of
subjecting the substrate to an elevated temperature after applying
the polyfluoropolyether silane.
[0153] For certain embodiments, including any one of the above
embodiments where the at least partially fluorinated composition
comprising at least one silane group further comprises an acid,
except where an elevated temperature is used, the method of the
invention further comprises the step of allowing the substrate to
dry at a temperature of about 15.degree. C. to about 30.degree. C.
after applying the composition.
[0154] In a preferred embodiment of the method of the invention for
making a coated metal article, the three steps of forming a
hardcoat layer by physical vapor deposition, forming a tie layer by
plasma deposition, applying an at least partially fluorinated
composition comprising at least one silane group by evaporation and
condensation are performed within a single deposition chamber. This
embodiment of the method of the invention is referred to herein as
the "triple hybrid" method.
[0155] In a most preferred embodiment of the triple hybrid method
of the invention, the hardcoat layer is formed using cathodic arc
deposition, the tie layer is formed using ion-assisted plasma
deposition, and the at least partially fluorinated composition is
applied by thermal evaporation and condensation of the
composition.
[0156] The triple hybrid method can be carried out in a deposition
apparatus with a common element for plasma creation and ion
acceleration. In one illustrative embodiment, the apparatus is a
stainless steel vacuum chamber, cylindrical in shape, which is
approximately two feet in diameter and two feet tall. The chamber
is pumped by a Varian diffusion pump, which is backed by a rotary
vane mechanical pump. The base pressure of the chamber is about
1.times.10.sup.-6 Torr. Coated metal articles of the invention can
be mounted to a substrate platen, which is rotated at a speed of
about 5 rpm. The substrate platen is electrically isolated from the
chamber and connected to a 5 kilowatt RF power supply through an
impedance matching transformer. The frequency of the applied RF
power is 40 kHz. A cathodic arc evaporation source is installed on
one of the flanges to the vacuum chamber. It comprises a 2 inch
diameter metal cathode, which is cooled by water directly in
contact with the back of the cathode. The cathode is connected to
the negative terminal of a 200 ampere DC power supply. The positive
terminal of the power supply is grounded to the chamber wall. A
mechanical igniter is utilized to initiate the arc on the cathode.
For plasma deposition of the tie layer, tetramethylsilane and
oxygen, for example, can be metered into the chamber through mass
flow controllers at prescribed flow rates. The plasma is initiated
by the 40 kHz power supply. Evaporation of the at least partially
fluorinated composition can be achieved, for example, by soaking a
graphite cloth with a prescribed amount of fluorocompound and
passing AC voltage to the graphite cloth to heat it in order to
flash vaporized the fluorocompound. Current to the cloth is
controlled by using a variable autotransformer (Variac).
[0157] After pumping the system to its base pressure, argon gas,
for example, is introduced into the chamber at a prescribed flow
rate and the RF power to the substrate platen is applied to create
a plasma around the platen comprising the metal article. The metal
article is cleaned in the argon plasma for prescribed amount of
time, followed by treatment in, for example, a nitrogen plasma.
Nitrogen gas at a prescribed flow rate is fed into the system and
the argon is turned off while maintaining the plasma through the
transition. After treating the metal article in a nitrogen plasma,
the cathodic arc is initiated by activating the mechanical igniter.
The nitrogen flow is maintained at the prescribed flow rate and the
arc is maintained at the prescribed current in the DC power supply
driving the cathodic arc discharge. After depositing the PVD
coating by the cathodic arc method, the DC power is shut off and
plasma priming is performed, for example, with oxygen and
tetramethylsilane gases for a prescribed amount of time. Upon
completion of the plasma priming resulting in the deposition of a
silicon-containing tie layer, the plasma is shut off and power is
applied to the graphite heating cloth to evaporate the
fluorocompound onto the metal article.
EXAMPLES
[0158] Objects and advantages of this invention are further
illustrated by the following examples, but the particular materials
and amounts thereof recited in these examples, as well as other
conditions and details, should not be construed to unduly limit
this invention.
Preparation of "HFPO-Silane"
[0159] "HFPO" refers to the end group
--F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)-- of the methyl ester
F(CF(CF.sub.3)CF.sub.2O).sub.aCF(CF.sub.3)C(O)OCH.sub.3, wherein a
averages from 4-20, which can be prepared according to the method
reported in U.S. Pat. No. 3,250,808, with purification by
fractional distillation.
[0160] HFPO-Silane, HFPO-CONHCH.sub.2CH.sub.2Si(OCH.sub.3).sub.3,
was prepared as follows. A 100 mL 3 necked round bottom flask
equipped with magnetic stir bar, N.sub.2 inlet and reflux condenser
was charged with HFPOCOOCH.sub.3 (20 g, 0.01579 moles) and
NH.sub.2CH.sub.2CH.sub.2CH.sub.2--Si(OCH.sub.3).sub.3 (2.82 g,
0.01579 moles) under N.sub.2 atmosphere. The reaction mixture was
heated at 75.degree. C. for 12 hours. The reaction was monitored by
IR and after the disappearance of the ester peak, clear viscous oil
was kept at high vacuum for another 8 hours and used as such as
described below.
General Procedure
[0161] The following general triple hybrid method was carried out
in a deposition apparatus, as described above, with a common
element for plasma creation and ion acceleration: [0162] Metal
articles were mounted onto the substrate platen [0163] Vacuum
chamber was closed [0164] Vacuum chamber was pumped to base
pressure [0165] Argon gas was introduced into the chamber [0166] RF
power was applied to the substrate platen [0167] Metal articles
were plasma cleaned in argon plasma [0168] Nitrogen gas was
introduced into the chamber [0169] Argon gas was disabled [0170]
Metal articles were plasma treated in nitrogen plasma [0171]
Cathodic arc discharge was ignited [0172] Nitrogen flow rate and
substrate power were adjusted [0173] Cathodic arc thin film was
deposited onto metal articles [0174] Cathodic arc discharge was
disabled [0175] Oxygen gas was introduced into the chamber [0176]
Nitrogen gas was disabled [0177] Metal articles were plasma treated
in oxygen plasma [0178] Tetramethylsilane (TMS) gas was introduced
into the chamber [0179] Metal articles were plasma treated in
oxygen plus TMS gas [0180] TMS gas was disabled [0181] Metal
articles were plasma treated in oxygen gas [0182] Oxygen gas was
disabled [0183] AC power was applied to the graphite heating cloth
[0184] Fluorocompound was evaporated and condensed onto metal
articles [0185] Power to the graphite cloth was disabled [0186] The
chamber was vented and metal articles were dismounted
Coating Evaluation: Tape Snap and Adhesive Removal Test
[0187] A tape snap/adhesive removal test was performed by applying
and "snapping off" (quickly removing) 3M Catalog number 165 storage
tape having an aggressive acrylic pressure sensitive adhesive ten
times from the surface of metal articles. Then 3M catalog number
007A rubber-based pressure sensitive transfer adhesive was applied
to the surface and rubbed off the surface with a finger. A relative
rating scale was used for the tape snap/adhesive removal test as
indicated in the table below.
TABLE-US-00001 Rating Description 1 Very easy to remove 007A
adhesive 2 Easy to remove 007A adhesive 3 Less easy to remove 007A
adhesive 4 Difficult to remove 007A adhesive 5 Very difficult to
remove 007A adhesive
Example 1
Scissor Blades with Titanium Nitride, Diamond Like Glass (DLG), and
Hexafluoropropyleneoxide (HFPO)-Silane Triple Layers
[0188] Stainless steel scissor blades were coated by the method of
this invention according to the General Procedure above. The
process parameters were as follows:
TABLE-US-00002 Flow Rate Pressure Rf Power DC Current Time Step Gas
(sccm) (mTorr) (watts) (amps) (min) 1 O2 380 39 1000 -- 30 2 Ar 300
39 1000 -- 30 3 N2 400 49 500 -- 5 4 N2 350 35 500 100 30 5 O2 380
38 500 -- 3 6 TMS/O2 150/380 100 500 -- 0.17 7 O2 380 55 500 --
3
[0189] During step 4 above, the cathodic arc source was enabled
with a titanium cathode to evaporate titanium vapor which reacts
with the nitrogen gas to deposit a titanium nitride hardcoat. The
arc current was maintained at 100 amperes, resulting in a voltage
of between 20 and 30 volts.
[0190] After completing the seven steps above, oxygen gas was
disabled and chamber pressure reduced to less than 5.times.10-5
Torr. After this, electrical power to the graphite cleaning cloth
was enabled and the HPPO-silane was evaporated onto the scissor
blades. The Variac heating was set to 20% of full scale
(approximately 20 volts) and the heating was left on for 60
seconds. Immediately following the HFPO deposition step, the
chamber was vented to atmosphere and the scissor blades taken out
of the system. The resulting blades had a gold color,
characteristic of the titanium nitride thin films, and had good
release characteristics as evidenced by the dewetting of Super
Sharpie.TM. marker ink.
Example 2
Scissor Blades with Titanium Nitride, DLG, and (HFPO)-Silane or
Perfluoropolyether Silane Triple Layers
[0191] A series of runs were completed on stainless steel scissor
blades in essentially the same fashion as in Example 1 with either
Novec.TM. EGC-1720, perfluoropolyether silane solubilized at 0.1
wt. % in hydrofluoroether solvent, available from 3M Company
("perfluoropolyether silane") or HFPO-silane as indicated in Table
1. The scissor blades were then evaluated using the tape snap and
adhesive removal test described above. The evaluation results are
included in Table 1.
TABLE-US-00003 TABLE 1 Tape Hard Snap/Adhesive Coating
Fluorochemical Removal Material Plasma Prime Coating Test Rating
TiN Oxidized Silane DLG Perfluoropolyether 1 silane TiN Oxidized
Silane DLG Perfluoropolyether 1 silane TiN Oxidized Silane DLG HFPO
Silane 1 TiN Oxidized Silane DLG HFPO Silane 1 TiN Oxidized Silane
DLG HFPO Silane 1
Example 3
Scissor Blades with Titanium Aluminum Nitride, DLG, and
Perfluoropolyether Silane Triple Layers
[0192] Stainless steel scissor blades with a 0.6 micron thick TiAlN
hardcoat deposited by physical vapor deposition were obtained from
a vendor. The blades were plasma primed with an oxidized silane DLG
layer essentially as described above. The primed blades were then
coated with EGC-1720 by wiping the surface of the scissors with a
cloth saturated in EGC-1720. After wiping, the coating was cured in
an oven at 120.degree. C. for 15 minutes. The resulting blades were
then evaluated using the tape snap and adhesive removal test
described above. After tape snapping the surface with 165 tape the
EGC-1720 coating was retained and the 007A adhesive was easy to rub
off.
Comparative Example
Scissor Blades with Titanium Aluminum Nitride, NO Tie Layer, and
Perfluoropolyether Silane
[0193] Scissor blades as described in Example 3 but without the DLG
tie layer were made. They were then evaluated using the tape snap
and adhesive removal test described above. Initially, they allowed
the 007A adhesive to be rubbed off easily; but after tape snapping
the surface with 165 tape, the EGC-1720 coating was mostly removed
and the 007A adhesive was difficult to rub off.
Example 4
Scissors with Titanium Aluminum Nitride, DLG, and
Perfluoropolyether Silane Triple Layers
[0194] Stainless steel scissors were made essentially as described
in Example 3. The scissors were evaluated using the tape snap and
adhesive removal test described above. After tape snapping the
surface with 165 tape the EGC-1720 coating was retained and the
007A adhesive was easy to rub off.
[0195] Then, the scissors were used to cut an 800 inch (20.32 m)
length roll of 165 tape lengthwise down the middle. No adhesive
build-up was observed on the blades, demonstrating good non-stick
properties.
[0196] Next, the scissors were used to cut Staples copy paper
10,000 times. Then, 007A adhesive was applied to the inside of the
blades and it was still very easy to rub off, which demonstrates
good durability by withstanding the abrasion of the blades
rubbing/cutting the paper 10,000 times.
[0197] These scissors were then used again to cut an 800 inch
(20.32 m) length roll of 165 tape lengthwise down the middle and no
adhesive build-up was observed on the blades, demonstrating good
non-stick properties after this durability test.
[0198] The complete disclosures of the publications cited herein
are incorporated by reference in their entirety as if each were
individually incorporated. Various modifications and alterations to
this invention will become apparent to those skilled in the art
without departing from the scope and spirit of this invention. It
should be understood that this invention is not intended to be
unduly limited by the illustrative embodiments and examples set
forth herein and that such examples and embodiments are presented
by way of example only with the scope of the invention intended to
be limited only by the claims set forth herein as follows.
* * * * *