U.S. patent application number 15/151114 was filed with the patent office on 2017-11-16 for conversion coating treatment.
The applicant listed for this patent is HAMILTON SUNDSTRAND CORPORATION. Invention is credited to Mark R. Jaworowski, Michael A. Kryzman, Blair A. Smith, Bart Antonie van Hassel, Georgios S. Zafiris, Weilong Zhang.
Application Number | 20170327955 15/151114 |
Document ID | / |
Family ID | 58709253 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170327955 |
Kind Code |
A1 |
Smith; Blair A. ; et
al. |
November 16, 2017 |
CONVERSION COATING TREATMENT
Abstract
A kit for applying a coating includes a first handheld container
with a first liquid trivalent chromium salt composition disposed
therein. A first applicator is disposed in fluid communication with
the first container and is configured to dispense the first
composition. The kit also includes a second handheld container
having a second liquid oxidizing agent composition disposed
therein. A second applicator is disposed in fluid communication
with the second container and is configured to dispense the second
composition.
Inventors: |
Smith; Blair A.; (South
Windsor, CT) ; Jaworowski; Mark R.; (Glastonbury,
CT) ; Zhang; Weilong; (Glastonbury, CT) ;
Kryzman; Michael A.; (West Hartford, CT) ; van
Hassel; Bart Antonie; (Weatogue, CT) ; Zafiris;
Georgios S.; (Glastonbury, CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HAMILTON SUNDSTRAND CORPORATION |
CHARLOTTE |
NC |
US |
|
|
Family ID: |
58709253 |
Appl. No.: |
15/151114 |
Filed: |
May 10, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B43M 11/08 20130101;
C23C 22/00 20130101; B43K 5/1845 20130101; C23C 22/83 20130101;
C23C 2222/10 20130101; C23C 22/73 20130101 |
International
Class: |
C23C 22/83 20060101
C23C022/83; C23C 22/73 20060101 C23C022/73 |
Claims
1. A kit for applying a conversion coating, comprising: a first
handheld container comprising a first liquid composition disposed
therein that comprises a trivalent chromium salt; a first
applicator in fluid communication with the first container
configured to dispense the first composition; a second handheld
container comprising a second liquid composition disposed therein
comprising an oxidizing agent; and a second applicator in fluid
communication with the second container configured to dispense the
second composition.
2. The kit of claim 1, comprising a housing that comprises a first
chamber as said first container and a second chamber as said second
container.
3. The kit of claim 1, comprising a first housing that comprises a
first chamber as said first container, and a second housing,
separate from the first housing, that comprises a second chamber as
the second container.
4. The kit of claim 1, wherein the applicators are each
independently selected from porous pads, brushes, rollers, or
nozzles.
5. The kit of claim 1, wherein the applicator in fluid
communication with the second container is configured to make
contact with a substrate to apply the second composition to the
substrate, and wherein the second container and the applicator in
fluid communication with it are configured to prevent fluid
communication from the applicator to the second container.
6. The kit of claim 1, comprising an oblong handheld housing that
comprises a first chamber as said first container and a second
chamber as said second container, a first applicator comprising a
porous pad disposed at a first end of the oblong housing in fluid
communication with the first chamber, and a second applicator
comprising a porous pad disposed at a second end of the oblong
housing in fluid communication with the second chamber.
7. The kit of claim 1, comprising a first oblong handheld housing
that comprises a first chamber as said first container and a first
applicator comprising a porous pad disposed at an end of the first
oblong housing in fluid communication with the first chamber, and a
second oblong housing that comprises a second chamber as said
second container and a second applicator disposed at an end of the
second oblong housing comprising a porous pad in fluid
communication with the second chamber.
8. The kit of claim 1, wherein the oxidizing agent is selected from
a peroxide, a permanganate salt, or combinations comprising the
foregoing.
9. The kit of claim 8, wherein the oxidizing agent comprises
hydrogen peroxide.
10. The kit of claim 9, wherein the second composition comprises
0.1 wt. % to 10 wt. % hydrogen peroxide, based on the total weight
of the second composition.
11. The kit of claim 1, wherein the second liquid composition is
configured to stay wet on a substrate for at least 0.5 minutes.
12. The kit of claim 1, further comprising instructions to apply a
plurality of passes of the second composition to a substrate at
intervals configured to maintain a wet layer of the second
composition on the substrate for at least 0.5 minutes.
13. The kit of claim 1, further comprising instructions to allow a
drying period of time after application of the first composition to
a substrate before applying the second composition.
14. A method of using the kit of claim 1, comprising applying a
coating of the first composition to a substrate, allowing a drying
period of time to pass, applying the second composition to the
coated substrate, and maintaining a wet layer of the second
composition on the coated substrate for at least 0.5 minutes.
15. The method of claim 14, comprising applying a plurality of
passes of the second composition to the coated substrate at
intervals configured to maintain a wet layer of the second
composition on the substrate for at least 0.5 minutes.
16. The method of claim 14, wherein the substrate comprises
aluminum, zinc, cadmium, tin, magnesium, iron, copper, silver, and
alloys thereof.
17. A method of protecting a trivalent chromium conversion-coated
substrate from corrosion, comprising contacting the substrate with
a porous pad disposed on and end of an oblong handheld housing in
fluid communication with a chamber disposed within the housing, and
dispensing a liquid composition comprising an oxidizing agent
disposed in the chamber onto the substrate through the porous
pad.
18. The method of claim 17, comprising applying a plurality of
passes of the second composition to the coated substrate at
intervals configured to maintain a wet layer of the second
composition on the substrate for at least 0.5 minutes.
19. The method of claim 17, comprising applying a plurality of
passes of the second composition to the coated substrate at
intervals configured to maintain a wet layer of the second
composition on the substrate for at least three minutes.
20. The method of claim 17, comprising applying a plurality of
passes of the second composition to the coated substrate at
intervals configured to maintain a wet layer of the second
composition on the substrate for at least five minutes.
Description
BACKGROUND
[0001] This disclosure relates to coatings for corrosion
protection, and more specifically to conversion coatings for
corrosion protection of metal substrates.
[0002] Many metals are subject to corrosion, which can be
exacerbated by exposure to corrosion-promoting environmental
conditions such as high-chloride environments found in proximity to
marine environments. Surface coatings have been used to provide
protection against corrosion by imposing a physical barrier between
the metal substrate and the surrounding environment. However,
conventional polymer surface coatings can suffer from a number of
problems such as inadequate or uneven thickness, pinholes and other
gaps in coating coverage, and the necessity of extensive surface
preparation of the substrate prior to application of the coating in
order to provide adequate bonding between the coating and the
substrate, in addition to the cost, time and complexity of applying
the polymer coating.
[0003] Metal surface treatments such as conversion coatings have
been used to protect metals such as aluminum, zinc, cadmium, tin,
magnesium, iron, copper, silver, and their alloys such as
zinc-nickel, tin-zinc, etc. Conversion coating compositions have
been commonly applied to large surface area substrates by immersion
or spray application. Such techniques, however, can be cumbersome
for touch-up application such as to repair abraded surfaces or at
connection interfaces between assembled metal components. Small
scale handheld application of conversion coatings has been
performed with felt pen-style applicators. Historically, chromate
conversion coatings utilizing hexavalent chromium have been
effectively used to provide corrosion protection. However, the use
of hexavalent chromium is largely in the process of being
discontinued due to toxicity concerns. Touch-up conversion coatings
based on trivalent chromium have been applied with felt pen-style
applicators; however, such trivalent conversion coatings have been
found to be less effective at preventing corrosion than conversion
coatings based on hexavalent chromium.
BRIEF DESCRIPTION
[0004] According to some aspects of this disclosure, a kit for
applying a coating comprises a first handheld container comprises a
first liquid composition disposed therein that comprises a
trivalent chromium salt. A first applicator is disposed in fluid
communication with the first container and is configured to
dispense the first composition. The kit also includes a second
handheld container comprises a second liquid composition disposed
therein comprising an oxidizing agent. A second applicator is
disposed in fluid communication with the second container and is
configured to dispense the second composition.
[0005] In some aspects, a method of using the above-described kit
comprises applying a coating of the first composition to a
substrate, allowing a drying period of time to pass, applying the
second composition to the coated substrate, and maintaining a wet
layer of the second composition on the coated substrate for at
least 0.5 minutes.
[0006] In some aspects, a method of protecting a trivalent chromium
conversion-coated substrate from corrosion comprises contacting the
substrate with a porous pad disposed on an end of an oblong
handheld housing in fluid communication with a chamber disposed
within the housing, and dispensing a liquid composition comprising
an oxidizing agent disposed in the chamber onto the substrate
through the porous pad.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The subject matter which is regarded as the present
disclosure is particularly pointed out and distinctly claimed in
the claims at the conclusion of the specification. The foregoing
and other features, and advantages of the present disclosure are
apparent from the following detailed description taken in
conjunction with the accompanying drawings in which:
[0008] FIG. 1 is a schematic depiction of a cross-sectional view of
an example embodiment of a kit for applying a conversion coating;
and
[0009] FIG. 2 is a schematic depiction of a cross-sectional view of
another example embodiment of a kit for applying a conversion
coating.
DETAILED DESCRIPTION
[0010] With reference now to the Figures, FIG. 1 schematically
depicts an example embodiment of a kit for applying a conversion
coating. As shown in FIG. 1, a first container in the form of
housing 10a has a liquid composition comprising a trivalent
chromium salt disposed in chamber 11a formed by the housing 10a and
barrier 12a. A second container in the form of housing 10b has a
liquid composition comprising an oxidizing agent disposed in
chamber 11b formed by the housing 10b and barrier 12b. The housings
10a and 10b can be configured in various shapes, sizes, and forms
in order to facilitate being held by hand during use. In some
embodiments, the housings are configured in an oblong configuration
as depicted in FIG. 1. In some embodiments, an oblong housing can
have a maximum linear dimension in a cross-sectional plane
perpendicular to the longest oblong axis in ranges having a lower
endpoint of 5 mm, more specifically 10 mm, and even more
specifically 15 mm, and an upper endpoint of 50 mm, more
specifically 40 mm, more specifically 30 mm, and even more
specifically 25 mm. In some embodiments, an oblong housing can be
configured as a cylinder. Such embodiments can also be referred to
as a "coating pen" or "coating pens". In some embodiments, the
cylinder can have a diameter in ranges having a lower endpoint of 5
mm, more specifically 10 mm, and even more specifically 15 mm, and
an upper endpoint of 50 mm, more specifically of 40 mm, more
specifically 30 mm, and even more specifically 25 mm. The above
upper and lower endpoints can be independently combined to disclose
various different ranges.
[0011] In some embodiments, the trivalent chromium salt composition
can be an aqueous solution or a non-aqueous solution comprising
trivalent chromium and various anions. Exemplary anions include
nitrate, sulfate, phosphate, and/or acetate. Specific exemplary
trivalent chromium salts can include Cr.sub.2(SO.sub.4).sub.3,
(NH).sub.4Cr(SO.sub.4).sub.2, KCr(SO.sub.4).sub.2,
CrF.sub.3Cr(NO3).sub.3, and mixtures comprising any of the
foregoing. The concentration of the trivalent chromium salt in the
composition, per liter of solution, can range from about 0.01 g to
about 22 g, more specifically from about 3 g to about 12 g, and
even more specifically from about 4 g to about 8.0 g. Embodiments
of compositions and the application thereof to substrates are
described in U.S. Pat. Nos. 5,304,257, 5,374,347, 6,375,726,
6,511,532, 6,521,029, and 6,511,532, the disclosures of which are
incorporated herein by reference in their entirety. Various
additives and other materials can be included in the composition
comprising trivalent chromium as disclosed in the patent
literature, and the trivalent chromium salt composition can be
selected from any of a number of known commercially-available
compositions.
[0012] In some embodiments, the oxidizing agent can be a peroxide
or a permanganate salt. In some embodiments, the oxidizing agent is
hydrogen peroxide (H.sub.2O.sub.2). Examples of peroxides other
than hydrogen peroxide include inorganic peroxides (e.g.
Li.sub.2O.sub.2, Na.sub.2O.sub.2, K.sub.2O.sub.2, BaO.sub.2), and
organic peroxides (e.g., R--OO--R', R--OO--H, or RCO--OO--R', where
R, and R' are organic groups). The oxidizing agent can be in
aqueous or non-aqueous solutions at concentrations in ranges having
a lower endpoint of 0.1 wt. %, more specifically 0.5 wt. %, more
specifically 1.0 wt. %, more specifically 2.0 wt. %, more
specifically 3.0 wt. %, and more specifically 4.0 wt. %, and an
upper endpoint of 10.0 wt. %, more specifically 9.0 wt. %, more
specifically 8 wt. %, more specifically 7 wt. %, more specifically
6 wt. %, more specifically 4 wt. %, and even more specifically 3.5
wt. %. The above upper and lower endpoints can be independently
combined to disclose various different ranges.
[0013] The compositions in the chambers 11a, 11b can be dispensed
by bringing the liquid compositions in the chambers 11a, 11b into
contact with the dispensing applicators 14a, 14b, respectively.
Each dispensing applicator 14a, 14b can independently be selected
as a porous material configured to transport the liquid composition
from the respective chamber 11a, 11b to a substrate in contact with
the outer surface of the applicator 14a, 14b. The liquid
composition can be brought into contact with the applicator 14a,
14b by bringing the dispensing applicator 14a, 14b into contact
with a fixed-position surface (which can but does not have to be
the substrate to be coated) and applying hand pressure on the
housing 10a, 10b toward the surface to open the poppet valve 15a,
15b. The dispensing applicators 14a, 14b are slideably mounted in
the housing 10a, 10b. At rest, the dispensing applicators 14a, 14b
are biased away from the main body of the housing 10a, 10b by
applicator biasing members (not shown) to an at-rest position as
shown in FIG. 1. This biasing force is transmitted through actuator
16a, 16b to apply an expansive force on the spring member 18a, 18b,
which intern acts on the poppet valve 15a, 15b to keep it engaged
on the barrier 12a, 12b and closed. Upon the application of hand
pressure urging housing 10a, 10b toward the surface, the
counteracting force of the surface acting on the dispensing each
applicator 14a, 14b compresses the spring member 18a, 18b until the
fully compressed spring and actuator engage against the poppet
valve 15a, 15b and displace it away from the barrier 12a, 12b to
open the poppet valve 15a, 15b. Hand pressure can be maintained to
keep the poppet valve open for a period of time sufficient to
charge a desired quantity of liquid into chamber 17a, 17b, at which
point the hand pressure can be removed or relaxed so that the
applicator biasing members again bias the applicators 14a, 14b to
the at-rest position with the poppet valve 15a, 15b closed. Liquid
in the chamber 17a, 17b can then continue to be delivered and
spread on the substrate. Of course, the applicators 14a, 14b are
not limited to porous pads. The applicators 14a, 14b could also be
independently selected from brushes, rollers, nozzles, etc. When
not in use, the applicators 14a, 14b can be covered with an air-
and liquid-tight cap.
[0014] Another example embodiment of a kit is schematically
depicted in FIG. 2, in which the first and second containers are
configured as first and second chambers 11a, 11b formed by housing
10 and barrier 20, with applicators 14a, 14b disposed at opposing
ends of the oblong or cylindrical housing 10. The remaining
components and features depicted in FIG. 2 and their operation are
as in FIG. 1, and do not require further explanation. The
embodiment depicted in FIG. 2 provides additional technical
benefits of convenience and efficiency, while reducing the
potential for cross-contamination between the compositions by
delivering the two distinct chemical compositions through
applicators disposed on opposite ends of a coating pen.
[0015] In some embodiments, avoidance of contamination from
chromium salts on the substrate being coated into the second
container comprising the oxidizing agent composition is promoted by
contamination-avoiding materials or components. In some
embodiments, the applicator 14b can be formed from a material that
is resistant to wicking of material from the coated substrate into
the chamber 17b from which it could potentially infiltrate to the
chamber 11b when the poppet valve 15b is open. Such materials can
include surfaces that are resistant to wetting by the coated
chromium salt composition. In some embodiments, the poppet valve
15b can include check-valve features (not shown, but known in the
valve art) to prevent migration of fluid from chamber 17b into
chamber 11b. In some embodiments, anti-contamination procedures can
be followed such as draining or flushing the chamber 17b after
application is complete, or using a surface other than the coated
substrate for displacing the applicator 14b to charge the chamber
17b so that the poppet valve 15b is closed before the applicator
14b comes into contact with the coated substrate. Combinations of
the above materials or procedures can be used as well.
[0016] In some embodiments, the first liquid composition comprising
the trivalent chromium salt can be allowed to contact the substrate
for a period of time before applying the second composition
comprising the oxidizing agent, and in some embodiments the kit can
include instructions to that effect. The amount of contact time can
vary considerably depending on the ambient temperature and
humidity, the specific properties of the applicator and the liquid
composition, and the thickness with which it is applied. Any amount
of contact time greater than zero can be used. In some embodiments,
contact times can range from 1 minute to 5 minutes. In some
embodiments, contact times can range from 1 minute to 3
minutes.
[0017] In some embodiments, a wet layer of the second liquid
composition comprising the oxidizing agent is maintained on the
coated substrate for a minimum period of time. Although this
disclosure is not bound by any theory of operation, it is believed
that the wet layer promotes chemical interaction of the oxidizing
agent with the trivalent chromium salt composition. Examples of
minimum wet layer time limits can include 0.5 minutes, more
specifically 1 minute, more specifically 1.5 minutes, more
specifically 2 minutes, more specifically 3 minutes, more
specifically 4 minutes, and even more specifically 5 minutes.
Theoretically there is no maximum wet layer time; however,
minimization of the opportunity costs of lost efficiency typically
results in drying times that do not drastically exceed the
specified minimum wet layer time. In some embodiments, a wet layer
of the second liquid composition comprising the oxidizing agent is
maintained by making a plurality of passes over the substrate with
the applicator 14b, and in some embodiments the kit can include
instructions to that effect. In some embodiments, the second liquid
composition can be configured to maintain a wet layer for a target
duration, e.g., through the inclusion of additives such as gel or
thickening agents (e.g., fused silica, water soluble polymers) or
lower volatility solvents. Moisture can also be retained by
film-forming agents in the first composition such as sodium or
potassium salts of hexafluorotitanic acid or hexafluorozirconic
acid, or the selection of a chromium salt with colligative
properties such as high solubility that render it inherently
slow-drying.
[0018] While the present disclosure has been described in detail in
connection with only a limited number of embodiments, it should be
readily understood that the present disclosure is not limited to
such disclosed embodiments. Rather, the present disclosure can be
modified to incorporate any number of variations, alterations,
substitutions or equivalent arrangements not heretofore described,
but which are commensurate with the spirit and scope of the present
disclosure. Additionally, while various embodiments of the present
disclosure have been described, it is to be understood that aspects
of the present disclosure may include only some of the described
embodiments. Accordingly, the present disclosure is not to be seen
as limited by the foregoing description, but is only limited by the
scope of the appended claims.
* * * * *