U.S. patent application number 14/639178 was filed with the patent office on 2016-04-14 for chemical agent resistant coating compositions.
The applicant listed for this patent is PPG Industries Ohio, Inc.. Invention is credited to Anthony M. Chasser, LAWRENCE J. FITZGERALD, DeAnna D. Katz.
Application Number | 20160102222 14/639178 |
Document ID | / |
Family ID | 54148610 |
Filed Date | 2016-04-14 |
United States Patent
Application |
20160102222 |
Kind Code |
A1 |
FITZGERALD; LAWRENCE J. ; et
al. |
April 14, 2016 |
CHEMICAL AGENT RESISTANT COATING COMPOSITIONS
Abstract
A chemical agent resistant coating composition can include a
fluoropolymer, a flatting agent, and a hydrophobic additive. When
the composition is applied to a substrate and cured as a coating,
the coating has an 85.degree. gloss of less than 3.5, a water
contact angle of greater than 80.degree., and desorbs a maximum of
180 micrograms of bis(2-chloroethyl) sulfide and a maximum of 40
micrograms of O-pinacolyl methylphosphonofluoridate, according to
testing under MIL-PRF-32348. A method of preparing chemical agent
resistant coating compositions and substrates at least partially
coated with the chemical agent resistant coating compositions are
also disclosed.
Inventors: |
FITZGERALD; LAWRENCE J.;
(Gibsonia, PA) ; Chasser; Anthony M.; (Allison
Park, PA) ; Katz; DeAnna D.; (Gibsonia, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PPG Industries Ohio, Inc. |
Cleveland |
OH |
US |
|
|
Family ID: |
54148610 |
Appl. No.: |
14/639178 |
Filed: |
March 5, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61948140 |
Mar 5, 2014 |
|
|
|
Current U.S.
Class: |
524/437 ;
524/520; 524/544 |
Current CPC
Class: |
C09D 127/12 20130101;
C09D 5/03 20130101; C08L 91/06 20130101; C08K 5/29 20130101; C08K
3/22 20130101; C09D 127/12 20130101; C09D 133/06 20130101; C09D
191/06 20130101; C08K 3/22 20130101; C08K 2003/2227 20130101 |
International
Class: |
C09D 127/12 20060101
C09D127/12; C09D 5/03 20060101 C09D005/03 |
Goverment Interests
NOTICE OF GOVERNMENT SUPPORT
[0002] This invention was made with Government support under
Contract No. W912HQ-13-C-0007 awarded by the Strategic
Environmental Research and Development Program.
Claims
1. A chemical agent resistant coating composition comprising: a
fluoropolymer, a flatting agent comprising at least 10 weight %
based on the total solids weight of the coating composition; and a
hydrophobic additive comprising a wax, wherein when the composition
is applied to a substrate and cured as a coating, the coating has
an 85.degree. gloss of less than 3.5, a water contact angle of
greater than 80.degree., and desorbs a maximum of 180 micrograms of
bis(2-chloroethyl) sulfide and a maximum of 40 micrograms of
O-pinacolyl methylphosphonofluoridate, according to testing under
MIL-PRF-32348.
2. The coating composition of claim 1, wherein the coating has a
water contact angle of greater than 100.degree..
3. The coating composition of claim 1, wherein the coating desorbs
a maximum of 80 micrograms of bis(2-chloroethyl) sulfide and a
maximum of 35 micrograms of O-pinacolyl
methylphosphonofluoridate.
4. The coating composition of claim 1, wherein the fluoropolymer
comprises polyvinylidene fluoride, chlorotrifluoroethylene
copolymer, or a combination thereof.
5. The coating composition of claim 1, wherein the flatting agent
comprises a metal hydroxide, metal oxide, silica, a hyperbranched
(meth)acrylic polymer, a polyurea particle, a polyolefin particle,
ground fiberglass, or mixtures thereof.
6. The coating composition of claim 1, wherein the fiberglass
comprises an average size dimension of 30 to 70 microns.
7. The coating composition of claim 1, wherein the wax is a
fluorinated wax.
8. The coating composition of claim 1, wherein the wax comprises
polytetrafluoroethylene wax, polytetrafluoroethylene-modified
polyethylene wax, polytetrafluoroethylene-modified polypropylene
wax, polyethylene wax, polypropylene wax, paraffinic wax, carnauba
wax, silicone wax, or combinations thereof.
9. The coating composition of claim 1, wherein the coating
composition further comprises a dispersible acrylic resin.
10. The coating composition of claim 9, wherein the acrylic resin
has an acid value of 10 to 100 mg KOH/g.
11. The coating composition of claim 9, wherein the acrylic resin
comprises greater than 50 weight % methyl (meth)acrylate based on
the total weight of the acrylic resin.
12. The coating composition of claim 9, wherein the acrylic resin
has a glass transition temperature of greater than 40.degree.
C.
13. The coating composition of claim 1, wherein the coating
composition is a powder coating composition.
14. The coating composition of claim 1, wherein the coating
composition further comprises a crosslinker.
15. The coating composition of claim 1, wherein the coating
composition is completely free of a crosslinker.
16. A substrate at least partially coated with the coating
composition of claim 1.
17. A method of preparing a chemical agent resistant coating
composition comprising mixing a fluoropolymer, a flatting agent
such that the flatting agent comprises at least 10 weight % of the
composition based on the total solid weight of the coating
composition, and a hydrophobic additive comprising a wax, wherein
when the coating composition is applied to a substrate and cured as
a coating, the coating has an 85.degree. gloss of less than 3.5, a
water contact angle of greater than 800, and desorbs a maximum of
180 micrograms of bis(2-chloroethyl) sulfide and a maximum of 40
micrograms of O-pinacolyl methylphosphonofluoridate, according to
testing under MIL-PRF-32348.
18. The method of claim 17, further comprising dispersing the
mixture in water.
19. The method of claim 17, further comprising drying the mixture
to form a powder coating composition.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 61/948,140, filed Mar. 5, 2014, the entire contents
of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0003] The present invention relates to chemical agent resistant
coating compositions, methods of making such coating compositions,
and substrates at least partially coated with a chemical agent
resistant coating composition.
BACKGROUND OF THE INVENTION
[0004] Chemical agent resistant coatings (also referred to as
"CARC") are commonly applied to military equipment, vehicles, and
aircrafts that can be exposed to chemical and biological agents.
Chemical agent resistant coatings resist biological and chemical
agents. After being exposed to biological and chemical agents,
biological and chemical agents may then be washed from the surface
of the coatings during a decontamination process. As such, chemical
agent resistant coatings are also designed to resist
decontamination wash solutions. In addition, certain military
specifications require that these coatings have an extremely low
gloss to minimize visual detection due to glare or reflection from
light sources.
[0005] While chemical agent resistant coatings have been developed
over the years, the types of chemical agent resistant coatings
currently available are limited. It is, therefore, desirable to
provide new chemical agent resistant coatings.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a chemical agent
resistant coating composition comprising: a fluoropolymer; a
flatting agent that comprises at least 10 weight % of the
composition based on the total solid weight of the coating
composition; and a hydrophobic additive that includes a wax. When
the composition is applied to a substrate and cured as a coating,
the coating has an 85.degree. gloss of less than 3.5, a water
contact angle of greater than 80.degree., and desorbs a maximum of
180 micrograms of bis(2-chloroethyl) sulfide and a maximum of 40
micrograms of O-pinacolyl methylphosphonofluoridate according to
testing under MIL-PRF-32348 (November 2010).
[0007] The present invention is also directed to a method of
preparing a chemical agent resistant coating composition. The
method comprises mixing a fluoropolymer, a flatting agent such that
the flatting agent comprises at least 10 weight % of the
composition based on the total solid weight of the coating
composition, and a hydrophobic additive that includes a wax so that
when the coating composition is applied to a substrate and cured as
a coating, the coating has an 85.degree. gloss of less than 3.5, a
water contact angle of greater than 800, and desorbs a maximum of
180 micrograms of bis(2-chloroethyl) sulfide and a maximum of 40
micrograms of O-pinacolyl methylphosphonofluoridate according to
testing under MIL-PRF-32348 (November 2010).
[0008] A substrate at least partially coated with the chemical
agent resistant coating compositions is also described herein.
DESCRIPTION OF THE INVENTION
[0009] For purposes of the following detailed description, it is to
be understood that the invention may assume various alternative
variations and step sequences, except where expressly specified to
the contrary. Moreover, other than in any operating examples, or
where otherwise indicated, all numbers expressing, for example,
quantities of ingredients used in the specification and claims are
to be understood as being modified in all instances by the term
"about". Accordingly, unless indicated to the contrary, the
numerical parameters set forth in the following specification and
attached claims are approximations that may vary depending upon the
desired properties to be obtained by the present invention. At the
very least, and not as an attempt to limit the application of the
doctrine of equivalents to the scope of the claims, each numerical
parameter should at least be construed in light of the number of
reported significant digits and by applying ordinary rounding
techniques.
[0010] Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the invention are approximations,
the numerical values set forth in the specific examples are
reported as precisely as possible. Any numerical value, however,
inherently contains certain errors necessarily resulting from the
standard variation found in their respective testing
measurements.
[0011] Also, it should be understood that any numerical range
recited herein is intended to include all sub-ranges subsumed
therein. For example, a range of "1 to 10" is intended to include
all sub-ranges between (and including) the recited minimum value of
1 and the recited maximum value of 10, that is, having a minimum
value equal to or greater than 1 and a maximum value of equal to or
less than 10.
[0012] In this application, the use of the singular includes the
plural and plural encompasses singular, unless specifically stated
otherwise. In addition, in this application, the use of "or" means
"and/or" unless specifically stated otherwise, even though "and/or"
may be explicitly used in certain instances. Further, in this
application, the use of "a" or "an" means "at least one" unless
specifically stated otherwise. For example, "a" fluoropolymer, "a"
flatting agent, "a" hydrophobic additive, "an" acrylic resin, and
the like refer to one or more of any of these items.
[0013] As indicated, the present invention is directed to a
chemical agent resistant coating composition that can include a
fluoropolymer, a flatting agent, and a hydrophobic additive. As
used herein, a "chemical agent resistant coating composition"
refers to a coating composition that when deposited onto a
substrate and cured as a coating, resists biological and chemical
agents. For example, chemical agent resistant coatings deposited
from the compositions described herein resist bis(2-chloroethyl)
sulfide (also known as Mustard Gas or HD) and O-pinacolyl
methylphosphonofluoridate (also referred to as Soman or GD).
Chemical agent resistant coatings deposited from the compositions
described herein can also resist other chemical and biological
agents known in the art.
[0014] As previously noted, the chemical agent resistant coating
compositions can include a fluoropolymer. As used herein, a
"polymer" refers to oligomers and both homopolymers and copolymers.
The term "resin" is used interchangeably with "polymer". Further,
the term "fluoropolymer" refers to polymers and copolymers
(including polymers having two or more different monomers,
including for example terpolymers) having a fluorine atom.
[0015] Non-limiting examples of fluoropolymers that can be used to
form the chemical agent resistant coating compositions of the
present invention include polyvinylidene fluoride (PVDF),
polyhexafluoropropylene (PHFP), polytetrafluoroethylene (PTFE),
polyperfluoromethylvinylether (PMVE), and combinations thereof, as
well as copolymers and terpolymers thereof. For example, the
fluoropolymer can be a chlorotrifluoroethylene copolymer, such as
the chlorotrifluoroethylene copolymer commercially available from
Asahi Glass Co. under the trade name LUMIFLON.RTM..
[0016] The fluoropolymers used with the coating compositions of the
present invention can be in solid or liquid form. For instance, the
fluoropolymer can be a solid polyvinylidene fluoride (PVDF), such
as the solid polyvinylidene fluoride (PVDF) commercially available
from Arkema under the trade name KYNAR.RTM.. Alternatively, the
fluoropolymer can be a liquid form of polyvinylidene fluoride
(PVDF).
[0017] The fluoropolymer can comprise at least 5 weight %, at least
8 weight %, at least 10 weight %, at least 20 weight %, at least 30
weight %, or at least 40 weight %, based on the total solids weight
of the coating composition. The fluoropolymer can comprise at most
70 weight %, at most 60 weight %, or at most 50 weight %, based on
the total solids weight of the composition. The fluoropolymer can
also comprise a range such as from 5 to 70 weight %, from 8 to 60
weight %, or from 10 to 50 weight %, based on the total solids
weight of the composition.
[0018] As indicated above, the chemical agent resistant coating
compositions can also include a flatting agent. As used herein, the
term "flatting agent" refers to a material added to a coating
composition to reduce the gloss of a coating formed from the
composition. The term "flatting agent" is interchangeable with the
term "matting agent".
[0019] Non-limiting examples of suitable flatting agents that can
be used with the coating compositions described herein include
metal hydroxides, ground fiberglass, metal oxides, silicas,
hyperbranched (meth)acrylic polymers, polyurea particles,
polyolefin particles, and mixtures thereof. The flatting agents
used with the coating compositions described herein can also have a
melting point of greater than 190.degree. C., or greater than
200.degree. C., or greater than 210.degree. C., or greater than
220.degree. C.
[0020] When silica is used as a flatting agent with the coating
composition, it can be used in various forms including, but not
limited to, amorphous, aerogel, diatomaceous, hydrogel, fumed, and
combinations thereof.
[0021] As used herein, the term "hyperbranched (meth)acrylic
polymer" refers to a polymer having a main polymer chain and at
least two branching points along the main polymer chain. The
hyperbranched (meth)acrylic polymers of the present invention can
exhibit an alpha parameter derived from the Mark-Houwink equation
of 0.2 to 0.7, or an alpha parameter derived from the Mark-Houwink
equation of 0.3 to 0.6. The Mark-Houwink relationship between molar
mass (M) and intrinsic viscosity (.eta.) ([.eta..]=K.M.alpha.
provides information about the structure of the polymer. The alpha
parameter indicates the degree of branching and can be determined
by multi detection size-exclusion chromatography as described by
Paillet et al, Journal of Polymer Science Part A: Polymer
Chemistry, 2012, 50, 2967-2979, which is incorporated by reference
herein. Further, the term (meth)acrylic refers to acrylic and
methacrylic, as well as their esters.
[0022] The hyperbranched (meth)acrylic polymers can be hydroxyl or
carboxyl group functional. Non-limiting examples of hyperbranched
(meth)acrylic polymers and methods of preparing them are described
in United States Patent Application Publication No. 2014/0275362 at
paragraphs [0016] to [0029], which are incorporated by reference
herein.
[0023] The hyperbranched (meth)acrylic polymer can have a weight
average molecular weight of greater than 3,000 g/mol, or greater
than 10,000 g/mol, or greater than 100,000 g/mol, or at least
200,000 g/mol, as determined by standard gel permeation
chromatography.
[0024] As noted, the flatting agent can include ground fiberglass.
As used herein, "ground fiberglass" refers to continuous strands of
glass fibers that have been extruded into fine filaments and ground
to a desired size. The ground fiberglass can have an average size
dimension of 30 to 70 microns, or 35 to 60 microns, or 35 to 55
microns, or 40 to 50 microns. The ground fiberglass can also have
an average size dimension that allows the fiberglass to be passed
through a 250 to 375 mesh filter, or a 275 to 350 mesh filter, or a
300 to 350 mesh filter, or a 325 mesh filter. As used herein,
"average size dimension" refers to the size of 50 weight percent or
more of the ground fiberglass in a sample.
[0025] Non-limiting examples of metal hydroxides that can be used
as a flatting agent include aluminum hydroxide, titanium hydroxide,
cobalt hydroxide, iron hydroxide, chrome hydroxide, tin hydroxide,
antimony hydroxide, manganese hydroxide, and combinations thereof.
Non-limiting examples of metal oxides that can be used as a
flatting agent include aluminum oxide, titanium oxide, cobalt
oxide, iron oxide, chrome oxide, tin oxide, antimony oxide,
manganese oxide, and combinations thereof. The metal oxide can form
crystal structures including, but not limited to, rutile, hematite,
spinel, and combinations thereof.
[0026] Non-limiting examples of polyurea particles that can be used
include those commercially available from Albemarle Corp. under the
trade name PERGOPAK.RTM. such as PERGOPAK.RTM. M3, M4, M5, and M6.
Other non-limiting examples include those commercially available
from Deuteron GmbH under the trade name Deuteron.RTM. MK and
MK-FF.
[0027] Non-limiting examples of polyolefin particles that can be
used as a flatting agent include polyethylene particles,
polypropylene particles, and combinations thereof. Such particles
can also be used as a dispersion.
[0028] The flatting agent can comprise at least 10 weight %, at
least 15 weight .degree. %, at least 20 weight %, at least 30
weight %, or at least 40 weight % based on the total solid weight
of the composition. The flatting agent can also comprise at most 80
weight %, at most 70 weight %, at most 60 weight %, or at most 50
weight %, based on the total solid weight of the composition. The
flatting can also comprise a range such as from 10 to 80 weight %,
from 20 to 70 weight %, from 20 to 50 weight %, from 30 to 40
weight %, or from 35 to 70 weight %, based on the total solid
weight of the composition.
[0029] The flatting agents described herein can be added to help
reduce the gloss of a coating. For example, the flatting agent can
be added to help obtain a chemical agent resistant coating having
an 85.degree. gloss of less than 3.5, less than 2.5, less than 2,
less than 1.5, less than 1, or less than 0.5. The flatting agent
can also help obtain a chemical agent resistant coating having a
60.degree. gloss of less than 3.5, less than 2.5, less than 2, less
than 1.6, less than 1.5, less than 1, or less than 0.5. The
60.degree. and 85.degree. gloss measurements are determined with a
Statistical Novo-Gloss 200 gloss meter.
[0030] The coating compositions of the present invention can also
include a hydrophobic additive. As used herein, the term
"hydrophobic additive" refers to a material that can increase the
water repellency of a coating. The hydrophobic additive used with
the coating compositions of the present invention are compatible
with the fluoropolymer, flatting agent, and other components
described herein. The hydrophobic additive can have a melting point
of less than 130.degree. C., or less than 120.degree. C., or less
than 110.degree. C., or less than 100.degree. C. Suitable
hydrophobic additives that can be used with the coating
compositions of the present invention include, but are not limited
to, waxes, such as fluorinated waxes for example. Non-limiting
examples of suitable waxes that can be used include
polytetrafluoroethylene wax, polytetrafluoroethylene-modified
polyethylene wax, polytetrafluoroethylene-modified polypropylene
wax, carnauba wax, silicone wax, polyethylene wax, polypropylene
wax, paraffinic wax, and mixtures thereof.
[0031] The hydrophobic additive can comprise at least 0.01 weight
%, at least 0.05 weight %, at least 0.1 weight %, at least 0.5
weight %, at least 1 weight %, at least 2 weight %, at least 3
weight %, or at least 5 weight %, based on the total solid weight
of the composition. The hydrophobic additive can comprise at most
20 weight %, at most 15 weight %, or at most 10 weight %, based on
the total solid weight of the composition. The hydrophobic additive
can also comprise a range such as from 0.01 to 20 weight %, from
0.1 to 15 weight %, from 0.5 to 15 weight %, from 1 to 10 weight %,
or from 3 to 10 weight %, based on the total solid weight of the
composition.
[0032] The chemical agent resistant coating compositions can
comprise a hydrophobic additive, fluoropolymer, and flatting agent
such that, when applied to a substrate as a coating, the coating
has a water contact angle of greater than 80.degree., or greater
than 90.degree., or greater than 100.degree., or greater than
110.degree.. The water contact angles may be measured with the
Kruss DSA 100. Methylene iodide and water may be used to determine
surface energy of panels. Typically, five drops of each liquid are
used with the contact angles measured four seconds after
deposition. Drop volume of 2.0 .mu.l for each liquid is used.
Contact angles are analyzed using the Owens-Wendt-Rabel and Kaelble
method to calculate surface energy. Temperature and humidity at the
time of testing may be 73.degree. F. and 49% RH.
[0033] In addition to extremely low gloss and high water contact
angles, coatings deposited from the coating compositions comprising
a hydrophobic additive, fluoropolymer, and flatting agent exhibit
superior durability and chemical resistance. For example, the
chemical agent resistant coatings resist bis(2-chloroethyl) sulfide
and O-pinacolyl methylphosphonofluoridate such that after exposure
to these chemical agents, the coatings desorb a maximum of 180
micrograms of bis(2-chloroethyl) sulfide and a maximum of 40
micrograms of O-pinacolyl methylphosphonofluoridate, according to
testing under United States military specification MIL-PRF-32348
(November 2010), which is incorporated by reference herein in its
entirety. Bis(2-chloroethyl) sulfide is commonly referred to as
Mustard Gas or HD, and O-pinacolyl methylphosphonofluoridate is
commonly referred to as Soman or GD. The coatings can also desorb a
maximum of 80 micrograms, a maximum of 70 micrograms, a maximum of
60 micrograms, a maximum of 50 micrograms, a maximum of 40
micrograms, a maximum of 30 micrograms, or a maximum of 20
micrograms of bis(2-chloroethyl) sulfide. In addition, the coatings
can desorb a maximum of 35 micrograms, a maximum of 30 micrograms,
a maximum of 25 micrograms, or a maximum of 20 micrograms of
O-pinacolyl methylphosphonofluoridate. The coatings deposited from
the coating compositions described herein can resist various other
chemical and biological agents known in the art.
[0034] As further required by MIL-PRF-32348 (November 2010), the
chemical agent resistant coatings are resistant to decontamination
solutions. For example, the chemical agent resistant coatings were
found to be resistant to super tropical bleach, a chlorinated lime,
as tested in accordance with MIL-PRF-32348 (November 2010).
[0035] Further, the chemical agent resistant coating compositions
can also include a dispersible resin. The resin can be water or
solvent dispersible. For example, the resin can be a water
dispersible acrylic resin having acid functionality. The term
"water dispersible" means that the resin is a polymer or oligomer
that is solubilized, partially solubilized, and/or dispersed in
some quantity of a water solution with or without additional water
soluble solvents. The solution, which can be used with the
compositions described herein, can be at least 50% water, at least
60% water, at least 70% water, at least 80% water, at least 90%
water, or 100% water, based on the total weight of the solution.
The solution can also be less than 50% cosolvent, at most 40%
cosolvent, at most 30% cosolvent, at most 20% cosolvent, or at most
10% cosolvent, based on the total weight of the solution. Suitable
cosolvents include, for example, aliphatic hydrocarbons, aromatic
hydrocarbons, ketones, esters, glycols, ethers, ether esters,
glycol ethers, glycol ether esters, alcohols, ether alcohols,
phthalate plasticizers, N-methyl pyrrolidone, and combinations
thereof. Phthalate plasticizers include phthalates esters such as
diethylhexyl phthalate, diisononyl phthalate, diisodecyl phthalate,
dioctyl phthalate, and butyl benzyl phthalate.
[0036] The dispersible resin can also be solvent dispersible, such
as a solvent dispersible acrylic resin having acid functionality. A
"solvent dispersible" resin is a polymer or oligomer that is
solubilized, partially solubilized, and/or dispersed in a solvent
solution where the majority of the solution is a solvent other than
water. Suitable solvents that make up the majority of such a
solution, which can be used with the compositions described herein,
include, but are not limited to, any of the cosolvents previously
described. For example, the solvent solution can comprise at least
50% cosolvent, at least 60% cosolvent, at least 70% cosolvent, at
least 80% cosolvent, at least 90% cosolvent, or 100% cosolvent,
based on the total weight of the solution. Such solvent solutions
can also include less than 50% water, at most 40% water, at most
30% water, at most 20% water, or at most 10% water, based on the
total weight of the solution.
[0037] The dispersible resin can comprise at least 50 weight %
methyl (meth)acrylate, at least 60 weight % methyl (meth)acrylate,
or at least 70 weight % methyl (meth)acrylate, based on the total
weight of the resin, as determined by standard gel permeation
chromatography.
[0038] The dispersible resin can also have an acid value of at
least 10 mg KOH/g, at least 20 mg KOH/g, or at least 30 mg KOH/g.
The dispersible resin can have an acid value of at most 100 mg
KOH/g, at most 90 mg KOH/g, at most 80 mg KOH/g, or at most 60 mg
KOH/g. The dispersible resin can also have an acid value range such
as from 10 to 100 mg KOH/g, from 5 to 60 mg KOH/g, or from 20 to 40
mg KOH/g.
[0039] Further, the dispersible resin can have a glass transition
temperature of greater than 40.degree. C., or greater than
50.degree. C., or greater than 60.degree. C., or greater than
70.degree. C. The glass transition temperature (Tg) is determined
by differential scanning calorimetry.
[0040] The dispersible resin can comprise at least 1 weight %, at
least 2 weight %, or at least 5 weight % of the coating
composition, based on the total solid weight of the composition.
The dispersible resin can comprise at most 20 weight %, at most 15
weight %, at most 10 weight %, or at most 7 weight % of the coating
composition, based on the total solid weight of the composition.
The dispersible resin can also comprise a range such as from 1 to
20 weight %, from 2 to 15 weight %, or from 2 to 7 weight % of the
coating composition, based on the total solid weight of the coating
composition.
[0041] A crosslinker can also be used with the chemical agent
resistant coating compositions. As used herein, a "crosslinker"
refers to a molecule comprising two or more functional groups that
are reactive with other functional groups and which is capable of
linking two or more monomers or polymer molecules through chemical
bonds. The crosslinker can be in solid or liquid form. Non-limiting
examples of suitable crosslinkers include hydroxyalkyl amides,
glycidyl functional acrylics, triglycidylisocyanurate,
carbodiimides, such as those commercially available from Dow as
UCARLINK, melamines, such as those available from Cytec as
CYMEL.RTM., and blocked isocyanates, such as those available from
Bayer as CRELAN.RTM..
[0042] Alternatively, the chemical agent resistant coating
compositions may be substantially free, essentially free, or
completely free of a crosslinker. The term "substantially free" as
used in this context means the coating compositions contain less
than 1000 parts per million (ppm), "essentially free" means less
than 100 ppm, and "completely free" means less than 20 parts per
billion (ppb) of a crosslinker.
[0043] The coating compositions of the present invention can also
include other optional materials well known in the art of
formulating coatings. For example, the coating compositions of the
present invention can also include a colorant. As used herein,
"colorant" refers to any substance that imparts color and/or other
opacity and/or other visual effect to the composition. The colorant
can be added to the coating in any suitable form, such as discrete
particles, dispersions, solutions, and/or flakes. A single colorant
or a mixture of two or more colorants can be used in the coatings
of the present invention.
[0044] Example colorants include pigments (organic or inorganic),
dyes and tints, such as those used in the paint industry and/or
listed in the Dry Color Manufacturers Association (DCMA), as well
as special effect compositions. A colorant may include, for
example, a finely divided solid powder that is insoluble, but
wettable, under the conditions of use. A colorant can be organic or
inorganic and can be agglomerated or non-agglomerated. Colorants
can be incorporated into the coatings by use of a grind vehicle,
such as an acrylic grind vehicle, the use of which will be familiar
to one skilled in the art.
[0045] Example pigments and/or pigment compositions include, but
are not limited to, carbazole dioxazine crude pigment, azo,
monoazo, diazo, naphthol AS, salt type (flakes), benzimidazolone,
isoindolinone, isoindoline and polycyclic phthalocyanine,
quinacridone, perylene, perinone, diketopyrrolo pyrrole,
thioindigo, anthraquinone, indanthrone, anthrapyrimidine,
flavanthrone, pyranthrone, anthanthrone, dioxazine,
triarylcarbonium, quinophthalone pigments, diketo pyrrolo pyrrole
red ("DPPBO red"), titanium dioxide, carbon black, and mixtures
thereof. The terms "pigment" and "colored filler" can be used
interchangeably.
[0046] Example dyes include, but are not limited to, those that are
solvent and/or aqueous based such as phthalo green or blue, iron
oxide, bismuth vanadate, anthraquinone, and peryleneand
quinacridone.
[0047] Example tints include, but are not limited to, pigments
dispersed in water-based or water miscible carriers such as
AQUA-CHEM 896 commercially available from Degussa, Inc., CHARISMA
COLORANTS and MAXITONER INDUSTRIAL COLORANTS commercially available
from Accurate Dispersions Division of Eastman Chemical, Inc.
[0048] The chemical agent resistant coating compositions can
include pigment particles that can comprise at least 1 weight %, at
least 3 weight %, or at least 5 weight % of the coating
composition, based on total solid weight of the coating
composition. The pigment particles can comprise at most 70 weight
%, at most 50 weight %, or at most 25 weight % of the coating
composition, based on total solid weight of the coating
composition. The pigment particles that can also comprise a range
such as from 1 to 70 weight %, from 3 to 50 weight %, or from 5 to
25 weight % of the coating composition, based on total solid weight
of the coating composition.
[0049] In addition, the coating compositions can also include
additional film-forming resins. For example, the coating
compositions can also include certain amounts of polyurethanes,
polyesters, polyamides, polyethers, polysiloxanes, epoxy resins,
vinyl resins, copolymers thereof, and combinations thereof. As used
herein, a "film-forming resin" refers to a resin that can form a
self-supporting continuous film on at least a horizontal surface of
a substrate upon removal of any diluents or carriers present in the
composition or upon curing.
[0050] Alternatively, the coating compositions may be substantially
free, essentially free, or completely free of additional
film-forming films such as those previously described. The term
"substantially free" as used in this context means the coating
compositions contain less than 1000 parts per million (ppm),
"essentially free" means less than 100 ppm, and "completely free"
means less than 20 parts per billion (ppb) of additional
film-forming films, such as those previously described.
[0051] Other non-limiting examples of materials that can be used
with the coating compositions of the present invention include
plasticizers, abrasion resistant particles, corrosion resistant
particles, corrosion inhibiting additives, fillers including, but
not limited to, micas, talc, clays, and inorganic minerals,
anti-oxidants, hindered amine light stabilizers, UV light absorbers
and stabilizers, surfactants, flow and surface control agents,
thixotropic agents, reactive diluents, catalysts, reaction
inhibitors, and other customary auxiliaries.
[0052] The present invention is also directed to a method of
preparing chemical agent resistant coating compositions. The method
can comprise mixing the fluoropolymer, flatting agent, and
hydrophobic additive such that when the coating composition is
applied to a substrate and cured as a coating, the coating has a
low gloss, high water contact angle, and excellent chemical
resistance. For instance, the fluoropolymer, flatting agent, and
hydrophobic additive can be mixed together such that when the
coating composition is applied to a substrate and cured as a
coating, the coating has an 85.degree. gloss of less than 3.5, a
water contact angle of greater than 80.degree., and desorbs a
maximum of 180 micrograms of bis(2-chloroethyl) sulfide and a
maximum of 40 micrograms of O-pinacolyl methylphosphonofluoridate,
according to testing under MIL-PRF-32348 (November 2010). The
method can also include mixing any of the other components
identified above including, but not limited to, a dispersible
acrylic resin, crosslinker, and/or colorant.
[0053] The method of preparing the chemical agent resistant coating
compositions can include dispersing the mixture in water.
Alternatively, the mixture can be dispersed in a solvent including,
but not limited to, any of the solvents described above. The
chemical agent resistant coating composition can then be applied to
a substrate as a liquid and cured to form a chemical agent
resistant coating. "Curing" refers to bond formation resulting in
the formation of a crosslinked coating. It will be appreciated that
the cure parameters will vary depending on the fluoropolymer,
flatting agent, hydrophobic additive, optional dispersible resin,
and other components, but such parameters can be readily determined
by one skilled in the art.
[0054] The chemical agent resistant coating composition can also be
applied to a substrate as a powder rather than as a liquid. As
such, the method can further include drying the mixture. The
mixture can be dried according to any means known in the art.
Suitable methods for drying are spray drying, tray drying, freeze
drying, fluid bed drying, single and double drum drying, flash
drying, swirl drying, and numerous other evaporation techniques.
The dry mixture can also be ground to a desired particle size.
Grinding can be accomplished by any means known in the art, such as
through the use of an air classifying mill.
[0055] As indicated, the fluoropolymer can be used in solid or
liquid form. The solid or liquid fluoropolymer can be dispersed in
water or solvent with the flatting agent, hydrophobic additive, and
other components, and optionally dried to form a powder using the
techniques described above.
[0056] The chemical agent resistant coating compositions can be
applied to a wide range of substrates known in the coatings
industry. For example, the chemical agent resistant coating
compositions can be applied to automotive substrates, industrial
substrates, packaging substrates, wood flooring and furniture,
apparel, electronics, including housings and circuit boards, glass
and transparencies, sports equipment, including golf balls, and the
like. These substrates can be, for example, metallic or
non-metallic. Metallic substrates include, but are not limited to,
tin, steel (including electrogalvanized steel, cold rolled steel,
hot-dipped galvanized steel, among others), aluminum, aluminum
alloys, zinc-aluminum alloys, steel coated with a zinc-aluminum
alloy, and aluminum plated steel. Non-metallic substrates include
polymeric, plastic, polyester, polyolefin, polyamide, cellulosic,
polystyrene, polyacrylic, poly(ethylene naphthalate),
polypropylene, polyethylene, nylon, EVOH, polylactic acid, other
"green" polymeric substrates, poly(ethyleneterephthalate) (PET),
polycarbonate, polycarbonate acrylobutadiene styrene (PC/ABS),
polyamide, wood, veneer, wood composite, particle board, medium
density fiberboard, cement, stone, glass, paper, cardboard,
textiles, leather both synthetic and natural, and the like.
[0057] The chemical agent resistant coating compositions of the
present invention are particularly useful when applied to
substrates used for military equipment, vehicles, and aircrafts.
For example, the chemical agent resistant coating compositions can
be applied to pretreated cold rolled steel, galvanized steel,
aluminum, or a combinations thereof that are found on military
equipment, vehicles, and aircrafts.
[0058] The coatings of the present invention can be applied by any
means standard in the art, such as electrocoating, spraying,
electrostatic spraying, dipping, rolling, brushing, and the like.
The coatings of the present invention can be applied to a dry film
thickness of at least 0.5 mil, 1 mil, or 2 mils. The coatings of
the present invention can be applied to a dry film thickness of at
most 5 mils, at most 4 mils, or at most 3 mils. The coatings of the
present invention can also be applied at a dry film thickness range
such as from 0.5 mil to 5 mils, such as from 1 mil to 4 mils, or
from 2 mils to 3 mils.
[0059] The coating compositions of the present invention may also
be used alone or in combination with primers, basecoats, and/or
topcoats. A "primer coating composition" refers to coating
compositions from which an undercoating may be deposited onto a
substrate in order to prepare the surface for application of a
protective or decorative coating system. A basecoat refers to a
coating composition from which a coating is deposited onto a primer
and/or directly onto a substrate optionally including components
(such as pigments) that impact the color and/or provide other
visual impact and which may be overcoated with a protective and
decorative coating system.
[0060] It will be appreciated from the following examples that the
coating compositions described herein provide coatings having
extremely low gloss, high water contact angles, and superior
chemical resistance, which meets the strict requirements to qualify
the coatings as a CARC. The following examples are presented to
demonstrate the general principles of the invention. The invention
should not be considered as limited to the specific examples
presented. All parts and percentages in the examples are by weight
unless otherwise indicated.
Example 1
Preparation of a Chemical Agent Resistant Coating Composition
[0061] A chemical agent resistant coating composition according to
the present invention was prepared with the following ingredients
shown in Table 1.
TABLE-US-00001 TABLE 1 Ingredients Weight (grams) LUMIFLON .RTM.
710 LF .sup.1 183.0 VESTAGON .RTM. B 1400 .sup.2 47.0
Tris(2,3-epoxypropyl)isocyanurate .sup.3 5.0 Benzoin .sup.4 1.5
V-12600 Green .sup.5 17.15 G-8599 Green .sup.6 20.05 MAPICO .RTM.
Tan 20A .sup.7 6.21 Carbazole Violet .sup.8 0.21 MODAFLOW .RTM.
.sup.9 2.5 IRGANOX .RTM. 1076 .sup.10 1.1 DT 3329 .sup.11 5.0
MARTINAL .RTM. Aluminum Hydroxide .sup.12 600.0 .sup.1
Chlorotrifluoroethylene copolymer, commercially available from
Asahi Glass. .sup.2 Polyisocyanate adduct having e-caprolactam
blocked NCO-groups, commercially available from Evonik Industries.
.sup.3 Trifunctional epoxy used as a crosslinking agent. .sup.4
2-hydroxy-1,2-di(phenyl)ethanone used as an anti-gassing additive.
.sup.5 Cobalt chromite based inorganic green color pigment,
commercially available from Ferro Corporation. .sup.6 Chromic oxide
based dark green pigment, commercially available from Elementis
Chemical Corp. .sup.7 Dark tan magnesium ferrite pigment,
commercially available from Rockwood Pigments. .sup.8 Dioxazine
blue tone pigment, commercially available from Crenovo
International Limited. .sup.9 Flow modifier, commercially available
from Cytec Industries. .sup.10 Sterically hindered phenolic
antioxidant, commercially available from Ciba Specialty Chemicals
Corp. .sup.11 Blend of wax and mercaptobenzothiazole, commercially
available from Huntsman Corp. .sup.12 Aluminum hydroxide,
commercially available from Albemarle Corp.
[0062] The ingredients shown in Table 1 were mixed in a Henschel
mixer. The mixed ingredients were then hot melt mixed on a 19MM
Baker Perkins extruder at rotational speeds of 350 rps. After melt
mixing, the mixture was allowed to cool. The resulting mixture was
then ground on a Micron unit ACM 1 to a particle size of 30
microns.
Example 2
Preparation of a Chemical Agent Resistant Coating Composition
[0063] A chemical agent resistant coating composition according to
the present invention was prepared with the following ingredients
shown in Table 2.
TABLE-US-00002 TABLE 2 Ingredients Weight (grams) Acrylic Resin
.sup.13 177.7 V-12600 Green .sup.5 9.6 G-8599 Green .sup.6 14.3
MAPICO .RTM. Tan 20A .sup.7 3.0 Carbazole Violet .sup.8 0.130
Pigment Black 7 .sup.14 0.024 MAPICO .RTM. Black Iron Oxide .sup.15
0.22 Portafill .RTM. A40 .sup.16 132.0 Methyl Isobutyl Ketone 6.4
TINUVIN .RTM. 144 .sup.17 1.0 TINUVIN .RTM. 900 .sup.18 0.55 LANCO
.TM. 1778 .sup.19 7.7 PRIMID .RTM. XL552/deionized 11.0 water mix
(1:1 ratio) .sup.20 KYNAR@ 500 .sup.21 56.0 .sup.13 Acrylic resin
having greater than 50 weight % methyl (meth)acrylate based on the
total weight of the acrylic resin, less than 12 weight %
methacrylic acid based on the total weight of the acrylic resin,
and a glass transition temperature of about 94.degree. C. .sup.14
Carbon black pigment. .sup.15 Iron oxide black pigment,
commercially available from Rockwood Pigments. .sup.16 Matting
filler produced from aluminum hydroxide, commercially available
from Sibelco Specialty Mineral Europe. .sup.17 Light stabilizer of
the hindered amine class, commercially available from Ciba
Specialty Chemicals Corp. .sup.18 UV absorber of the
hydroxyphenylbenzotriazole class, commercially available from Ciba
Specialty Chemicals Corp. .sup.19 Micronized PTFE-modified
polyethylene wax, commercially available from Lubrizol Advanced
Materials Inc. .sup.20 Hydroxyalkylamide crosslinker, commercially
available from EMS-GRILTECH, mixed with deionized water at a ratio
of 1:1. .sup.21 Solid polyvinylidene fluoride, commercially
available from Arkema.
[0064] The ingredients shown in Table 2 were weighed into a 1000 ml
container and mixed with a Cowles mixer for 20 to 40 minutes or
until a particle size of +6 was obtained, as measured on a Hegman's
gauge. The mixture was dried by conventional techniques known in
the art. The resulting sheet was then ground on a Micron unit ACM 1
to a particle size of 30 microns.
Example 3
Preparation of a Chemical Agent Resistant Coating Composition
[0065] A chemical agent resistant coating composition according to
the present invention was prepared with the following ingredients
shown in Table 3.
TABLE-US-00003 TABLE 3 Ingredients Weight (grams) Acrylic Resin
.sup.22 177.7 V-12600 Green .sup.5 9.6 G-8599 Green .sup.6 14.3
MAPICO .RTM. Tan 20A .sup.7 3.0 Carbazole Violet .sup.8 0.130
Pigment Black 7 .sup.14 0.024 MAPICO .RTM. Black Iron Oxide .sup.15
0.22 TEXO .RTM. ground fiberglass .sup.23 90 Methyl Isobutyl Ketone
6.4 TINUVIN .RTM. 144 .sup.17 1.0 TINUVIN .RTM. 900 .sup.18 0.55
LANCO .TM. 1778 .sup.19 7.7 PRIMID .RTM. XL552/deionized 11.0 water
mix (1:1 ratio) .sup.20 KYNAR .RTM. 500.sup.21 56 .sup.22 Acrylic
resin having greater than 50 weight % methyl (meth)acrylate based
on the total weight of the acrylic resin, less than 12 weight %
methacrylic acid based on the total weight of the acrylic resin,
and a glass transition temperature of about 69.degree. C. .sup.23
TEXO .RTM. ground fiberglass is washed, ground and filtered through
a 325 mesh filter - supplied by PPG Industries.
[0066] The ingredients shown in Table 3 were weighed into a 1000 ml
container and mixed with a Cowles mixer for 20 to 40 minutes or
until a particle size of +6 was obtained, as measured on a Hegman's
gauge. The mixture was dried by conventional techniques known in
the art. The resulting sheet was then ground on a Micron unit ACM 1
to a particle size of 30 microns.
Example 4
Preparation and Evaluation of Chemical Agent Resistant Coatings
[0067] The chemical agent resistant coating compositions of
Examples 1-3 were each sprayed onto a cold rolled steel metal panel
as a powder composition with an electrostatic spray at 75 k. The
coating compositions were sprayed at a thickness of 2 to 3 mils.
Panels were then baked for 15-25 minutes at a temperature of
425.degree. F. The resulting coatings were evaluated for various
properties, the results of which are shown in Table 4.
TABLE-US-00004 TABLE 4 Performance/Physical EXAMPLE 1 EXAMPLE 2
Example 3 Properties Testing Results Testing Results Testing
Results 60.degree. Gloss .sup.24 1 0.2 0.4 85.degree. Gloss .sup.24
1.4 0.3 0.5 MEK Double Rubs .sup.25 +100 +100 +100 Adhesion .sup.26
5B 5B 5B Recoat .sup.27 Pass Pass Pass Ra Value .sup.28 200
.mu.inch 270 .mu.inch 260 .mu.inch CARC HD <3 .mu.g <13 .mu.g
42 .mu.g Desorption .sup.29 CARC GD <3 .mu.g <13 .mu.g 28
.mu.g Desorption .sup.30 Super Tropical Bleach Pass Pass Pass
Resistance .sup.31 340 QUV 1000 hrs .sup.32 100% gloss 100% gloss
100% gloss retention retention retention WOM 1000 hrs .sup.33 100%
gloss 100% gloss 100% gloss retention retention retention Water
Contact 84.degree. 110.degree. 105.degree. Angle .sup.34 .sup.24
60.degree. and 85.degree. gloss was measured with a Statistical
Novo-Gloss 20.degree. gloss meter, available from Paul N. Gardner
Company, Inc. .sup.25 MEK double rubs refers to the chemical
resistance of the coatings to methyl ethyl ketone (MEK), evaluated
in accordance with ASTM 04752-10(2015). .sup.26 Adhesion measured
in accordance with ASTM D3359-09e2. Adhesion is assessed on a scale
of 0 to 5. .sup.27 Recoating was performed and evaluated in
accordance with MIL-PRF-32348 (November 2010), section 4.6.13,
which requires that the recoating of a dried film produce no
lifting, softening, or other film irregularity. .sup.28 Ra value is
the surface roughness of a coating, which was measured with a
Surtronic 25 profilometer. .sup.29 CARC HD is the measure of the
retention of bis(2-chloroethyl) sulfide in accordance with
MIL-PRF-32348 (November 2010) section 3.6.10 and 4.6.19 type III
coatings. .sup.30 CARC GD is the measure of the retention of
O-pinacolyl methylphosphonofluoridate in accordance with
MIL-PRF-32348 (November 2010) section 3.6.10 type III coatings.
.sup.31 Super tropical bleach is a chlorinated lime and is used to
test chemical resistance in accordance MIL-PRF-32348 (November
2010), section 4.6.18. .sup.32 Gloss retention test method
according to ASTM D4214-07. .sup.33 Gloss retention test method
according to SAE J2025-1989. .sup.34 Water contact angles were
measured with the Kruss DSA 100. Methylene iodide and water were
used to determine surface energy of panels. Five drops of each
liquid were used with the contact angles measured four seconds
after deposition. Drop volume of 2.0 .mu.l for each liquid was
used. Contact angles were analyzed using the Owens-Wendt-Rabel and
Kaelble method tocalculate surface energy. Temperature and humidity
at the time of testing were 73.degree. F. and 49% RH.
[0068] As shown in Table 4, coatings deposited from the chemical
agent resistant coatings compositions of the present invention
exhibited extremely low gloss, high water contact angles, and
superior chemical resistance to both Mustard Gas and Soman, as well
as to other chemicals, including those used as decontamination
solutions. The coatings deposited from the coating compositions of
Examples 1-3 also exhibited excellent weather resistance, adhesion
to substrates, and smoothness.
[0069] The present invention also includes the following
clauses.
[0070] Clause 1: A chemical agent resistant coating composition
comprising: a fluoropolymer, a flatting agent comprising at least
10 weight % of the composition based on the total solids weight of
the coating composition, and a hydrophobic additive comprising a
wax, wherein when the composition is applied to a substrate and
cured as a coating, the coating has an 850.degree. gloss of less
than 3.5, a water contact angle of greater than 80.degree., and
desorbs a maximum of 180 micrograms of bis(2-chloroethyl) sulfide
and a maximum of 40 micrograms of O-pinacolyl
methylphosphonofluoridate, according to testing under
MIL-PRF-32348.
[0071] Clause 2: The coating composition of clause 1, wherein the
coating has a water contact angle of greater than 1000.
[0072] Clause 3: The coating composition of any of clauses 1-2,
wherein the coating desorbs a maximum of 80 micrograms of
bis(2-chloroethyl) sulfide and a maximum of 35 micrograms of
O-pinacolyl methylphosphonofluoridate.
[0073] Clause 4: The coating composition of any of clauses 1-3,
wherein the fluoropolymer comprises polyvinylidene fluoride,
chlorotrifluoroethylene copolymer, or a mixture thereof.
[0074] Clause 5: The coating composition of any of clauses 1-4,
wherein the flatting agent comprises a metal hydroxide, metal
oxide, silica, a hyperbranched (meth)acrylic polymer, a polyurea
particle, a polyolefin particle, ground fiberglass, or mixtures
thereof.
[0075] Clause 6: The coating composition of clause 5, wherein the
fiberglass comprises an average size dimension of 30 to 70
microns.
[0076] Clause 7: The coating composition of clause 1, wherein the
wax is a fluorinated wax.
[0077] Clause 8: The coating composition of clause 1, wherein the
wax comprises polytetrafluoroethylene wax,
polytetrafluoroethylene-modified polyethylene wax,
polytetrafluoroethylene-modified polypropylene wax, polyethylene
wax, polypropylene wax, paraffinic wax, carnauba wax, silicone wax,
or combinations thereof.
[0078] Clause 9: The coating composition of any of clauses 1-8,
wherein the coating composition further comprises a dispersible
acrylic resin.
[0079] Clause 10: The coating composition of clause 9, wherein the
acrylic resin has an acid value of 10 to 100 mg KOH/g.
[0080] Clause 11: The coating composition of any of clauses 9-10,
wherein the acrylic resin comprises greater than 50 weight % methyl
(meth)acrylate based on the total weight of the acrylic resin.
[0081] Clause 12: The coating composition of any of clauses 9-11,
wherein the acrylic resin has a glass transition temperature of
greater than 40.degree. C.
[0082] Clause 13: The coating composition of any of clauses 1-12,
wherein the coating composition is a powder coating
composition.
[0083] Clause 14: The coating composition of any of clauses 1-13,
wherein the coating composition further comprises a
crosslinker.
[0084] Clause 15: The coating composition of any of clauses 1-13,
wherein the coating composition is completely free of a
crosslinker.
[0085] Clause 16: A substrate at least partially coated with the
coating composition of any of clauses 1-15.
[0086] Clause 17: A method of preparing a chemical agent resistant
coating composition comprising mixing a fluoropolymer, a flatting
agent such that the flatting agent comprises at least 10 weight %
of the composition based on the total solid weight of the coating
composition, and a hydrophobic additive comprising a wax, wherein
when the coating composition is applied to a substrate and cured as
a coating, the coating has an 85.degree. gloss of less than 3.5, a
water contact angle of greater than 80.degree., and desorbs a
maximum of 180 micrograms of bis(2-chloroethyl) sulfide and a
maximum of 40 micrograms of O-pinacolyl methylphosphonofluoridate,
according to testing under MTL-PRF-32348.
[0087] Clause 18: The method of clause 17, further comprising
dispersing the mixture in water.
[0088] Clause 19: The method of any of clauses 17-18, further
comprising drying the mixture to form a powder coating
composition.
[0089] Whereas particular embodiments of this invention have been
described above for purposes of illustration, it will be evident to
those skilled in the art that numerous variations of the details of
the present invention may be made without departing from the
invention as defined in the appended claims.
* * * * *