U.S. patent application number 10/680801 was filed with the patent office on 2004-05-27 for anti-corrosion composition.
Invention is credited to Garrett, David William, Miller, Shawn D., Simendinger, William H. III.
Application Number | 20040099845 10/680801 |
Document ID | / |
Family ID | 32094065 |
Filed Date | 2004-05-27 |
United States Patent
Application |
20040099845 |
Kind Code |
A1 |
Simendinger, William H. III ;
et al. |
May 27, 2004 |
Anti-corrosion composition
Abstract
The present invention provides an anti-corrosion composition
which can be applied to various substrates. The composition
comprises a glass matrix formed by crosslinking a mixture of an
amine-functionalized silane and an alkoxy-functionalized siloxane,
an epoxy and a compatabilizing agent for coupling the epoxy and the
alkoxy-functionalized siloxane of the glass matrix.
Inventors: |
Simendinger, William H. III;
(Raleigh, NC) ; Garrett, David William; (Marietta,
GA) ; Miller, Shawn D.; (Raleigh, NC) |
Correspondence
Address: |
Myers Bigel Sibley & Sajovec, P.A.
P. O. Box 37428
Raleigh
NC
27627
US
|
Family ID: |
32094065 |
Appl. No.: |
10/680801 |
Filed: |
October 7, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60417708 |
Oct 10, 2002 |
|
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|
Current U.S.
Class: |
252/389.32 |
Current CPC
Class: |
C08G 59/4085 20130101;
C09D 163/00 20130101; C09D 183/14 20130101; C08G 59/44 20130101;
C09D 163/00 20130101; C09D 163/00 20130101; C08L 83/00 20130101;
C08L 2666/04 20130101 |
Class at
Publication: |
252/389.32 |
International
Class: |
C23F 011/00 |
Claims
That which is claimed is:
1. An anti-corrosion composition comprising: (a) a glass matrix
formed by crosslinking a mixture of an amine-functionalized silane
and an alkoxy-functionalized siloxane; (b) an epoxy; and (c) a
compatabilizing agent for coupling the epoxy and the
alkoxy-functionalized siloxane of the glass matrix.
2. The anti-corrosion composition according to claim 1, wherein the
anti-corrosion composition further comprises a curing agent
3. The anti-corrosion composition according to claim 1, wherein the
compatibilizing agent is 3-(glycidoxypropyl)trimethoxysilane.
4. The anti-corrosion composition according to claim 1, wherein the
epoxy is bifunctional.
5. The anti-corrosion composition according to claim 2, wherein the
curing agent is an amine.
6. The anti-corrosion composition according to claim 4, wherein the
anti-corrosion composition further includes an aminosilane
compatible with the amine curing agent.
7. The anti-corrosion composition according to claim 1, wherein the
alkoxy-functionalized siloxane is selected from the group
consisting of polydiethoxysiloxane, polydimethoxysiloxane,
tetramethoxy silane and tetraethoxy silane.
8. The anti-corrosion composition according to claim 1, wherein the
composition further comprises an additive.
9. The anti-corrosion composition according to claim 7, wherein the
additive is selected from the group consisting of fumed silica,
mica, kaolin, bentonite, talc, zinc oxides, zinc phosphates, iron
oxides, cellulose, pigments, polytetrafluoroethylene powder, ultra
high molecular weight polyethylene powder, high, medium and low
molecular weight polyethylene powder.
10. The anti-corrosion composition according to claim 1, wherein
the glass matrix is crosslinked using an organotitanate or tin
catalyst.
11. A method of treating a substrate to prevent corrosion, the
method comprising: (a) applying to the substrate a composition
comprising a glass matrix formed by crosslinking a mixture of an
amine-functionalized silane and an alkoxy-functionalized siloxane,
an epoxy, and a compatiblizing agent for coupling the epoxy and the
alkoxy-functionalized siloxane of the glass matrix; (b)
crosslinking the composition to provide an epoxy-modified network
of glass and epoxy.
12. The method of treating a substrate to prevent corrosion
according to claim 11, wherein the compatibilizing agent is
3-(glycidoxypropyl)trimeth- oxysilane.
13. The method of treating a substrate to prevent corrosion
according to claim 11, wherein the anti-corrosion composition
further includes an aminosilane compatible with the amine curing
agent.
14. The method of treating a substrate to prevent corrosion
according to claim 11, wherein the composition further comprises an
additive.
15. The method of treating a substrate to prevent corrosion
according to claim 11, wherein the additive is selected from the
group consisting of filmed silica, mica, kaolin, bentonite, talc,
zinc oxides, zinc phosphates, iron oxides, cellulose, pigments,
polytetrafluoroethylene powder, ultra high molecular weight
polyethylene powder, high, medium and low molecular weight
polyethylene powder.
16. The method of treating a substrate to prevent corrosion
according to claim 11, wherein the glass matrix is crosslinked
using an organotitanate or tin catalyst.
17. A substrate having applied thereto an anti-corrosion
composition comprising a glass matrix formed by crosslinking a
mixture of an amine-functionalized silane and an
alkoxy-functionalized siloxane, an epoxy, and a compatabilizing
agent for coupling the epoxy and the alkoxy-functionalized siloxane
of the glass matrix.
18. The substrate according to claim 17 wherein the substrate is a
metal.
19. The substrate according to claim 17, wherein the anti-corrosion
composition further comprises a curing agent
20. The substrate according to claim 17, wherein the
compatibilizing agent is 3-(glycidoxypropyl)trimethoxysilane.
21. The substrate according to claim 17, wherein the epoxy is
bifunctional.
22. The substrate according to claim 19, wherein the curing agent
is an amine.
23. The substrate according to claim 17, wherein the anti-corrosion
composition further includes an aminosilane compatible with the
amine curing agent.
24. The substrate according to claim 17, wherein the
alkoxy-functionalized siloxane is selected from the group
consisting of polydiethoxysiloxane, polydimethoxysiloxane,
tetramethoxy silane and tetraethoxy silane.
25. The substrate according to claim 17, wherein the composition
further comprises an additive.
26. The substrate according to claim 25, wherein the additive is
selected from the group consisting of fumed silica, mica, kaolin,
bentonite, talc, zinc oxides, zinc phosphates, iron oxides,
cellulose, pigments, polytetrafluoroethylene powder, ultra high
molecular weight polyethylene powder, high, medium and low
molecular weight polyethylene powder.
27. The substrate according to claim 17, wherein the glass matrix
is crosslinked using an organotitanate or tin catalyst.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application No. 60/417,708; filed on Oct. 10, 2002, the disclosure
of which is incorporated herein by reference in its entirety.
FIELD AND BACKGROUND OF THE INVENTION
[0002] The present invention relates to an anti-corrosion
composition suitable for use on a variety of substrates. Of
particular interest is the use of the composition as a coating for
corrosive industrial environments such as smoke stacks, rail cars,
hoppers, factory floors, pipe linings, engine rooms and the
like.
[0003] Metal substrates and related parts in such industrial
environments are subjected to a number of acids and bases due to
the variety of compositions that pass through, contact, or are
contained in the industrial environment. For example, a rail car
may have a solvent such as a highly polar alcohol sitting in the
rail car for months or even longer periods of time. Similarly, an
acid such as sulphuric acid may be generated due to an industrial
process and caused to exit a smokestack on a substantially constant
basis. Often, the only way to avoid the corrosive nature of such
acids or bases is to completely scrap the article after a period of
use. Alternatively, use of the article can be discontinued so that
a lengthy cleaning can occur. These alternatives are expensive and
can lead to long down times caused by replacement or the
discontinued use. It would be desirable to have an alternative that
would allow the article to be used for a longer time. Thus, there
is a need for an anti-corrosive coating that can withstand a wide
variety of acid or base conditions, and can be simply and
inexpensively applied to a substrate.
SUMMARY OF THE INVENTION
[0004] The anti-corrosion composition of the present invention
includes a glass matrix formed by crosslinking a mixture of an
amine-functionalized silane and an alkoxy-functionalized siloxane,
an epoxy, and optionally and preferably a compatibilizing agent for
coupling the epoxy and the alkoxy-functionalized siloxane of the
glass matrix. The epoxy can further include a curing agent,
preferably an amine. The amine-functionalized silane preferably is
compatible with the amine curing agent. The composition, once
crosslinked, is an epoxy-modified interpenetrating network of glass
and epoxy. The present invention also provides a treated substrate
for use in an industrial environment, and includes various metals
such as steel, stainless steel, aluminium, magnesium and zinc.
DETAILED DESCRIPTION OF THE INVENTION
[0005] As discussed above, the anti-corrosion composition comprises
a glass matrix formed by crosslinking a mixture of an
amine-functionalized silane and an alkoxy-functionalized siloxane,
an epoxy, and, optionally, a compatibilizing agent for coupling the
epoxy and the alkoxy-functionalized siloxane of the glass matrix.
The glass matrix is crosslinked using a titanium or tin catalyst.
Suitable catalysts include, without limitation, titanium alkoxides
such as titanium methoxide, titanium ethoxide, titanium
isopropoxide, titanium propoxide, titanium butoxide, titanium
diisopropoxide (bis 2,4-pentanedionate), titanium diisopropoxide
bis(ethylacetoacetateo)titanium ethylhexoxide, and organic tin
compounds such as dibutyl tin diacetate, dibutyltin dilaurate,
dimethyl tin dineodecanoate, dioctyl dilauryl tin, and dibutyl
butoxy chlorotin, as well as mixtures thereof. The glass matrix can
be formed by using a Sol-Gel process such as described in U.S. Pat.
No. 6,313,193, the disclosure of which is incorporated herein by
reference in its entirety. Other methods of forming the matrix will
be within the skill of one in the art. The glass matrix provides
good adhesion to the surface being coated, as well as toughness,
crack resistance, durability, abrasion resistance, heat resistance
and stability in the particular environment.
[0006] The matrix formulation may also include fillers (e.g., fumed
silica, mica, kaolin, bentonite, talc), zinc oxides, zinc
phosphates, iron oxides, cellulose, pigments, corrosion inhibitors,
UV light stabilizers, thixotropic agents, epoxy modifiers,
polytetrafluoroethylene powder, ultra high molecular weight
polyethylene powder, high, medium and low molecular weight
polyethylene powder, or other additives, as will be readily
apparent to those skilled in the art.
[0007] Suitable amino-functionalized silanes include
3-aminopropyltriethoxy silane, 3-aminopropyldimethylethoxy silane,
3-aminopropyl methyldiethoxy silane and 3-aminopropyltrimethoxy
silane. Suitable alkoxy-functionalized siloxanes include
polydiethoxysiloxane, tetraethoxysilane, tetramethoxysilane and
polydimethoxy siloxane. Inasmuch as these compounds form silicates
through a water condensation reaction, the inherent moisture of
metal being treated can be used to facilitate the reaction without
having to remove the moisture. Thus substrates such as stem pipes
can be easily and inexpensively treated by using the moisture on
the outside of the pipe to facilitate the crosslinking
reaction.
[0008] Epoxy compounds are well known and are described in, for
example, U.S. Pat. Nos. 2,467,171; 2,615,007; 2,716,123; 3,030,336;
and 3,053,855 which are incorporated herein by reference in their
entirety. Useful epoxy compounds include the polyglycidyl ethers of
polyhydric polyols, such as ethylene glycol, triethylene glycol,
1,2-propyleneglycol, 1,5-pentanediol, 1,2,6-hexanetriol, glycerol
and 2,2-bis(4-hydroxy cyclohexyl)propane; the polyglycidyl esters
of aliphatic or aromatic polycarboxylic acids, such as oxalic acid,
succinic acid, glutaric acid, terephthalic acid, 2,6-naphthalene
dicarboxylic acid and dimerized linoleic acid; the polyglycidyl
ethers of polyphenols, such as 2,2-bis(4-hydroxyphenyl)propane
(commonly known as bis-phenol A), 1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)isobutane, 4,4'-dihydroxybenzophenone,
2,2-bis(4hydroxyphenyl)butane, bis(2-dihydroxynaphthyl)methane,
phloroglucinol, bis(4hydroxyphenyl)sulfo- ne,
1,5-dihydroxynaphthalene, and novolak resins; with the bifunctional
epoxies such as polyglycidyl ethers of a polyphenol, polybisphenol
A-epichlorohydrin glycidyl end-capped and polybisphenol
F-epichlorodydrin glycidyl end-capped being currently
preferred.
[0009] Generally the preferred epoxy compounds are resins having an
epoxide equivalent weight of about 100 to 2000, preferably about
110 to 500. A presently preferred epoxy is EPON 862 available from
Resolution Performance Products, Houston, Tex. Epoxy modifiers may
be added to improve flexibility.
[0010] Suitable curing agents include Ancamide 220, a polyamide
curing agent available from Air Products, Allentown, Pa.
[0011] Silanes capable of compatibilizing the epoxy and the
alkoxy-functionalized siloxane include glycidyl-modified silanes
such as 3-(glycidoxypropyl)trimethoxysilane,
3-(glycidoxypropyl)dimethylethoxysil- ane and
3-(glycidoxypropyl)methyldimethoxysilane. Benzyl alcohol can also
be used to help compatibilize the epoxy and alkoxy-functionalized
siloxane.
[0012] The matrix preferably comprising about 10 to 50 percent by
weight of the glass matrix, about 5 to 50 percent by weight epoxy,
0 to 10 percent by weight compatibilizing agent and 5 to 20 percent
by weight curing agent.
[0013] In operation, the anti-corrosion composition of the present
invention can be applied by roll-coating, brush, spray coating,
dipping and the like. As discussed above, it is preferred that the
user mix the catalyst with the other components right before or
substantially contemporaneously with application. The composition
is preferably applied at a thickness of about 0.25 mm to 1.0
mm.
EXAMPLES
[0014] The following examples are provided to afford a better
understanding of the present invention to those skilled in the art.
It is to be understood that these examples are intended to be
illustrative only and are not intended to limit the invention in
any way.
Example 1
[0015]
1 Component wt (%) Epon 862 epoxy resin 10.98 Ancamide 220
polyamide curing agent 10.98 (3-glycidoxypropyl)trimethoxysilane
14.00 3-aminopropyltriethoxys- ilane 6.98 polydiethoxysiloxane
12.16 titanium isopropoxide 5.75 benzyl alcohol 4.72 pigment 1.57
mica flakes 32.96
[0016] The composition is formulated such that the epoxy
functionality on the 3-(glycidoxypropyl)-methoxysilane is at a 1:1
stoichiometric ratio with the amine functionality of the Ancamide
220. The epoxy functionality of the 862 resin is at a 1:1
stoichiometric ratio with the amine functionality of the
aminopropyl triethoxysilane. The ethoxy groups on polydiethoxy
siloxane are at a 1:1 stoichiometric ratio with the sum of the
number of moles of aminopropyl triethoxysilane and the
3-(glycidoxyproply)trimethoxysilane.
[0017] Pencil hardness measurements of the coating after 7 days
indicate that the coating has a hardness value of 6H. Samples were
exposed to toluene, MEK, ethanol, paint thinner, 50% acetic acid
and grill cleaner (e.g., potassium hydroxide, ethylene glycol
monobutyl ether and monoethanolamine) for a period of 1 hour under
a watch glass.
[0018] Pencil hardness measurements were then conducted on the
areas of the sample which had been exposed to the chemical. For all
cases, except the acids, there were no changes in the pencil
hardness. Samples formulated with mica and exposed to the acids
decreased in hardness to H or less. Samples formulated with glass
and exposed to the acids only decreased in hardness to 5H.
Example 2
[0019]
2 Component wt (%) Epon 862 (epoxy resin) 8.34
3-(glycidoxypropyl)trimethoxy silane 10.63 polydiethoxy siloxane
9.24 titanium isopropoxide 4.29 Heucophos ZPO (organo-zinc
corrosion inhibitor) 8.20 Heucorin RZ (zinc salt corrosion
inhibitor) 0.91 Custermica A325 (mica) 35.76 fumed silica TS-720
(thixotropic agent) 0.89 Kronos 2160 (titanium oxide) 5.97 Vulcan
XC72R (carbon black) 0.12 Ancamide 220 (polyamide curing agent)
8.34 3-aminopropyltriethoxy silane 5.31 Hostavin N24 (UV light
stabilizer) 2.00
[0020] The resulting coating displays good adhesion with
conventional topcoats. It is more thermally resistant than
conventional epoxy resins. Using ASTM G26 and continuous exposure
to a xenon arc for 500 hours, no cracking or delamination occurs.
With respect to fluid resistance, ASTM D5402 is used to test a
variety of fluids. The coating is resistant to toluene, paint
remover, ethanol, brake fluid, grill cleaner, mineral spirits, MEK
and caustic acid.
Example 3
[0021]
3 Component wt (%) Epon 862 (epoxy resin) 4.99 Heloxy 505 (epoxy
modifier) 4.99 3-(glycidoxypropyl)methyldiethoxy silane 10.52
polydiethoxy siloxane 9.15 titanium isopropoxide 4.24 Heucophos ZPO
(organo-zinc corrosion inhibitor) 8.11 Heucorin RZ (zinc salt
corrosion inhibitor) 0.90 Custermica A325 (mica) 35.39 fumed silica
TS-720 (thixotropic agent) 0.88 Kronos 2160 (titanium oxide) 5.91
Vulcan XC72R (carbon black) 0.11 Ancamide 220 (polyamide curing
agent) 9.43 3-aminopropyltriethoxy silane 3.38 Hostavin N24 (UV
light stabilizer) 2.00
[0022] In the specification and example, there have been disclosed
typical preferred embodiments of the invention and, although
specific terms are employed, they are used in a generic and
descriptive sense only and not for purposes of limitation of the
scope of the invention set forth in the following claims.
* * * * *