U.S. patent application number 14/207731 was filed with the patent office on 2014-09-18 for method to control corrosion of a metal surface using alkyl sulfamic acids or salts thereof.
This patent application is currently assigned to BUCKMAN LABORATORIES INTERNATIONAL, INC.. The applicant listed for this patent is BUCKMAN LABORATORIES INTERNATIONAL, INC.. Invention is credited to Thomas E. McNeel, Jesse Pokrzywinski, Marilyn Whittemore.
Application Number | 20140272138 14/207731 |
Document ID | / |
Family ID | 50391528 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140272138 |
Kind Code |
A1 |
Pokrzywinski; Jesse ; et
al. |
September 18, 2014 |
Method To Control Corrosion Of A Metal Surface Using Alkyl Sulfamic
Acids Or Salts Thereof
Abstract
The present invention provides a method of inhibiting corrosion
of a metal surface with at least one alkyl sulfamic acid or salt
thereof to the metal surface in an amount effective to inhibit
corrosion of the metal surface. The alkyl sulfamic acid or salt
thereof can be applied in any suitable manner to the metal surface,
for example, flowing, coating, sponging, wiping, spraying,
painting, showering, and/or misting.
Inventors: |
Pokrzywinski; Jesse;
(Lakeland, TN) ; Whittemore; Marilyn; (Germantown,
TN) ; McNeel; Thomas E.; (Memphis, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BUCKMAN LABORATORIES INTERNATIONAL, INC. |
MEMPHIS |
TN |
US |
|
|
Assignee: |
BUCKMAN LABORATORIES INTERNATIONAL,
INC.
MEMPHIS
TN
|
Family ID: |
50391528 |
Appl. No.: |
14/207731 |
Filed: |
March 13, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61783706 |
Mar 14, 2013 |
|
|
|
Current U.S.
Class: |
427/255.23 ;
427/327; 427/331; 427/421.1; 427/427; 427/429 |
Current CPC
Class: |
C23F 11/10 20130101;
C10G 75/02 20130101; C10M 135/10 20130101; C23F 11/163 20130101;
C10M 2219/044 20130101; C10M 173/00 20130101; C23F 11/16 20130101;
C23F 11/164 20130101; C10N 2030/12 20130101 |
Class at
Publication: |
427/255.23 ;
427/429; 427/421.1; 427/427; 427/327; 427/331 |
International
Class: |
C23F 11/16 20060101
C23F011/16 |
Claims
1. A method of inhibiting corrosion of a metal surface comprising:
applying at least one alkyl sulfamic acid or salt thereof to the
metal surface in an amount effective to inhibit corrosion of the
metal surface.
2. The method of claim 1, wherein said alkyl sulfamic acid is a
C.sub.1-C.sub.12 alkyl sulfamic acid or salt thereof.
3. The method of claim 1, wherein the at least one alkyl sulfamic
acid has the formula R.sub.1R.sub.2NS(O).sub.2(OH), and R.sub.1 and
R.sub.2 are independently a hydrogen, a C.sub.4-C.sub.20 alkyl
group, or a cycloalkyl group, and R1 and R2 are not both hydrogen,
and/or R.sub.1, R.sub.2, and the N form a 5-8 membered heterocyclic
ring including one or more of O, NH, and CH.sub.2.
4. The method of claim 1, wherein R.sub.1 and R.sub.2 are
independently a hydrogen, a C.sub.4-C.sub.20 alkyl group, or a
cycloalkyl group, and R.sub.1 and R.sub.2 are not both
hydrogen.
5. The method of claim 1, wherein R.sub.1 or R.sub.2, but not both,
is a C4-C.sub.20 alkyl group or a cycloalkyl group.
6. The method of claim 1, wherein both R.sub.1 and R.sub.2 are a
C.sub.4-C.sub.20 alkyl group or cycloalkyl group.
7. The method of claim 1, wherein R.sub.1, R.sub.2, and the N form
a 5-8 membered heterocyclic ring including one or more of O, NH,
and CH.sub.2.
8. The method of claim 1, wherein the alkyl sulfamic acid or salt
thereof is present in a fluid applied to the metal surface.
9. The method of claim 8, wherein the fluid is a liquid.
10. The method of claim 8, wherein the fluid is a vapor.
11. The method of claim 8, wherein the fluid comprises at least one
of H.sub.2O, NH.sub.3, and an alcohol.
12. The method of claim 8, wherein the fluid comprises an acid or
base in addition to the alkyl sulfamic acid or salt thereof.
13. The method of claim 8, wherein the fluid comprises a salt
solution of at least one salt independent of a alkyl sulfamic acid
salt.
14. The method of claim 1, wherein the applying comprises one or
more of flowing, coating, sponging, wiping, spraying, painting,
showering, and misting of the at least one alkyl sulfamic acid or
salt thereof.
15. The method of claim 1, wherein the applying comprises flowing a
fluid comprising the at least one alkyl sulfamic acid or salt
thereof over the metal surface.
16. The method of claim 1, wherein the metal surface is a
non-ferrous surface.
17. The method of claim 1, wherein the metal surface comprises
copper or a copper-containing alloy.
18. The method of claim 1, further comprising contacting the metal
surface with at least one corrosive agent.
19. The method of claim 16, wherein the applying is performed
before, during, and/or after the contacting.
20. The method of claim 1, wherein the metal surface is part of a
closed fluid system.
Description
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of prior U.S. Provisional Patent Application No.
61/783,706, filed Mar. 14, 2013, which is incorporated in its
entirety by reference herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to the inhibition of corrosion
of a metal surface using one or more anti-corrosion agents.
[0003] Corrosion has been the subject of scientific study for more
than 150 years. Corrosion is a naturally occurring phenomenon that
relates to the deterioration of a material or its properties
because of a reaction with its environment. In addition to reduced
longevity, corrosion also produces oxides that can further
deteriorate a system by erosion, plugging, and fouling. Oxides can
deposit on heat transfer surfaces, reducing efficiency, and
increasing energy costs. Common sources of corrosion include
dissolved oxygen, bacteria, electrolysis (stray current),
differential metal (dielectric), and differential cells. Flow,
temperature, and pressure can effect the corrosion rate.
[0004] Corrosion inhibitors are used in oil and gas exploration and
production, petroleum refining, chemical manufacturing, heavy
manufacturing, water treatment, and the product additive
industries. As products and manufacturing processes have become
more complex and the consequences of corrosion more costly, greater
attention is being given to the control and prevention of
corrosion. Thus, there is a continued need to identify more
effective corrosion inhibitors that minimize financial and
environmental costs with better toxicological profiles.
SUMMARY OF THE INVENTION
[0005] A feature of the present invention is to inhibit corrosion
of a metal surface.
[0006] Another feature of this invention is to provide methods of
using an anti-corrosion agent having low toxicity and/or high
efficacy to prevent or minimize the corrosion of metal
surfaces.
[0007] Methods of inhibiting the corrosion of metal surfaces
located in a variety of different systems and environments are also
features of this invention.
[0008] To achieve these and other advantages and in accordance with
the purposes of the present invention, as embodied and broadly
described herein, the present invention provides a method of
inhibiting corrosion of a metal surface including applying at least
one alkyl sulfamic acid or salt thereof to the metal surface in an
amount effective to inhibit corrosion of the metal surface. At
least one alkyl sulfamic acid or salt thereof can be applied in any
suitable manner to the metal surface, for example, the application
can include one or more of the following: flowing, coating,
sponging, wiping, spraying, painting, showering, and misting. The
method can further include subjecting the treated metal surface
with corrosive agent(s).
[0009] Additional features and advantages of the present invention
will be set forth in part in the description which follows, and in
part will be apparent from the description, or may be learned by
practice of the present invention. The objectives and other
advantages of the present invention will be realized and obtained
by means of the elements and combinations particularly pointed out
in the written description and appended claims.
[0010] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are only intended to provide a further
explanation of the present invention, as claimed.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
[0011] The present invention provides a method of inhibiting
corrosion of a metal surface including applying at least one alkyl
sulfamic acid or salt thereof or a solution containing the alkyl
sulfamic acid or salt, to the metal surface in an amount effective
to inhibit corrosion of the metal surface. Any type of corrosion
can be inhibited as characterized by cause and/or effect. For
example, the corrosion can include uniform corrosion that extends
evenly across the surface, pitting corrosion that is uneven and has
smaller deep areas (pits), exfoliation corrosion that moves along
layers of elongated grains, and/or intergranular corrosion that
grows along grain boundaries.
[0012] Any suitable or desirable alkylated derivative of sulfamic
acid, salt thereof, combinations thereof can be used in the present
invention. More than one alkylated derivative of sulfamic acid or
salt thereof can be used. Sulfamic acid is also known as
amidosulfonic acid, amidosulfuric acid, aminosulfonic acid, and
sulfamidic acid. Sulfamic acid is a molecular compound having the
formula H.sub.3NSO.sub.3. Sulfamates can be O-substituted,
N-substituted-, or di-/tri-substituted derivatives of sulfamic acid
and are also considered to be sulfamic acids or salts thereof for
purposes of the present invention. Both tautomers H.sub.3NSO.sub.3
and H.sub.2NSO.sub.2(OH) fall within the scope of sulfamic acids or
salts thereof in the present invention. Alkylated derivatives of
these sulfamic acids can be used.
[0013] The alkylated derivative of sulfamic acid can thus be an
alkyl sulfamic acid or salt thereof. The alkyl group can contain
any desirable number of carbons in a linear, branched, and/or
cyclic configuration. For example, the alkyl group can be methyl,
ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl,
dodecyl, isopropyl, isobutyl, sec-butyl, tert-butyl, neopentyl, and
the like. The at least one sulfamic acid can have the formula
R.sub.1R.sub.2NS(O).sub.2(OH), and, for example, R.sub.1 and
R.sub.2 are independently a hydrogen, a C.sub.4-C.sub.20 alkyl
group, or a cycloalkyl group, and R.sub.1 and R.sub.2 are not both
hydrogen, and/or R.sub.1, R.sub.2, and the N form a 5-8 membered
heterocyclic ring including one or more of O, NH, and CH.sub.2. The
at least one alkyl sulfamic acid can have the formula
R.sub.1R.sub.2NS(O).sub.2(OH) and, for example, R.sub.1 and R.sub.2
can independently be a hydrogen, a C.sub.4-C.sub.20 alkyl group, or
a cycloalkyl group, and R.sub.1 and R.sub.2 are not both hydrogen.
The at least one alkyl sulfamic acid can have the formula
R.sub.1R.sub.2NS(O).sub.2(OH), and, for example, R.sub.1 or
R.sub.2, but not both, is a C.sub.4-C.sub.20 alkyl group or a
cycloalkyl group. The at least one alkyl sulfamic acid can have the
formula R.sub.1R.sub.2NS(O).sub.2(OH) and, for example, both
R.sub.1 and R.sub.2 are a C.sub.4-C.sub.20 alkyl group or
cycloalkyl group. The at least one alkyl sulfamic acid can have the
formula R.sub.1R.sub.2NS(O).sub.2(OH) and, for example, R.sub.1,
R.sub.2, and the N form a 5-8 membered heterocyclic ring including
one or more of O, NH, and CH.sub.2. The sulfamic acid or salt
thereof can be a halide derivative of a sulfamic acid. Examples of
sulfamic acids and salts thereof that can be alkylated (if not so
already) employed in the method of the present invention include
those described in U.S. Pat. Nos. 7,576,041; 7,470,652; 7,345,202;
6,983,614; 6,824,668; 6,380,182; 6,110,387; 6,103,131; 5,478,461;
5,431,839; 4,386,060; 4,327,034; 4,049,709; 3,223,704; and
3,536,759, which are incorporated herein by reference in their
entireties. Salts include, but are not limited to, alkali metal and
quaternary ammonium salts. Methods for the preparation of various
sulfamic acids or salts thereof are described in Nickless,
Inorganic Sulphur Chemistry, Elsevier Publishing Company, New York;
611-614 (1968), which is incorporated by reference in its
entirety.
[0014] The alkyl sulfamic acid or salt thereof can be applied by
itself to a metal surface or applied as part of a fluid that can
optionally contain one or more additional components, for example,
an additional anti-corrosion agent and/or a biocide. When combined
with one or more additional anti-corrosion agents, the resulting
corrosion inhibition can be sub-additive, additive, or
super-additive (synergistic). The fluid can include a liquid, a
vapor (gas), or a combination thereof. The fluid can include
H.sub.2O, NH.sub.3, and/or an alcohol. The fluid can be aqueous,
non-aqueous, or both. The fluid can include an acid or base in
addition to the alkyl sulfamic acid or salt thereof. The fluid can
include a salt solution of at least one salt independent of an
alkyl sulfamic acid salt.
[0015] The fluid containing the alkyl sulfamic acid or salt thereof
can be cooled or heated, or be used at ambient temperature or other
temperatures above or below 20 deg C. The pH of the fluid can be
neutral or from about 0.0 to about 14, from about 2.0 to about 12,
from about 4.0 to about 10, or from about 6.0 to about 8.0.
[0016] The concentration of the at least one alkyl sulfamic acid or
salt thereof can be adjusted according to the particular metal
surface(s) being treated and the parameters of the system in which
it is employed. The concentration of at least one alkyl sulfamic
acid or salt thereof in a fluid system can be less than 0.001 ppm,
greater than 0.001 ppm, from about 0.001 ppm to about 10,000 ppm
from about 0.01 to about 1,000 ppm, from about 0.1 ppm to about 100
ppm, or from about 1.0 ppm to about 50 ppm, or from about 0.5 ppm
to about 25 ppm, or from about 1 ppm to about 15 ppm, or from about
1 ppm to about 10 ppm, or from about 1 ppm to about 5 ppm. The
alkyl sulfamic acid or salt thereof can be prepared as a stock
solution of from about 0.01 wt % to about 100 wt %, from about 0.1
wt % to about 95 wt %, from about 1.0 wt % to about 80 wt %, from
about 5.0 wt % to about 75 wt %, from about 10 wt % to about 60 wt
%, from about 15 wt % to about 50 wt % from about 25 wt % to about
40 wt % alkyl sulfamic acid or salt thereof based on the total
weight of the stock solution. The alkyl sulfamic acid or salt
thereof can be used in the methods of the invention as a solid,
liquid, and/or gaseous formulation. The methods according to the
invention can be part of an overall water treatment regimen. The
alkyl sulfamic acid or salt thereof can be used with other water
treatment chemicals, such as biocides (e.g., algicides, fungicides,
bactericides, molluscicides, oxidizers, etc.), stain removers,
clarifiers, flocculants, coagulants, or other chemicals commonly
used in water treatment.
[0017] Depending on its use, a composition containing alkyl
sulfamic acid or salt thereof according to the present invention
can be prepared in various forms known in the art. For example, the
composition can be prepared in liquid form as a solution,
dispersion, emulsion, suspension, or paste; a dispersion,
suspension, or paste in a non-solvent; or as a solution by
dissolving the alkyl sulfamic acid or salt thereof in a solvent or
combination of solvents. Suitable solvents include, but are not
limited to, acetone, glycols, alcohols, ethers, water, or other
water-dispersible solvents. The composition can be prepared as a
liquid concentrate for dilution prior to its intended use. Common
additives such as surfactants, emulsifiers, dispersants, and the
like can be used as known in the art to increase the solubility of
the alkyl sulfamic acid or its salt as well as other components in
a liquid composition or system, such as an aqueous composition or
system. The composition of the invention can be solubilized by
simple agitation.
[0018] A composition of the present invention can be prepared in
solid form. For example, the alkyl sulfamic acid or salt thereof
can be formulated as a powder or tablet using means known in the
art. The tablets can contain a variety of excipients known in the
tableting art such as dyes or other coloring agents. Other
components known in the art such as fillers, binders, glidants,
lubricants, or antiadherents can be included. These components can
be included to improve tablet properties and/or the tableting
process.
[0019] The alkyl sulfamic acid, salt thereof, and/or composition
including the same can be applied directly or indirectly to a metal
surface using any appropriate technique, for example flowing,
coating, sponging, wiping, spraying, painting, showering, and/or
misting of the at least one alkyl sulfamic acid or salt thereof to
the metal surface can be employed. The "applying" can include
flowing a fluid containing the at least one alkyl sulfamic acid or
salt thereof over the metal surface. The method can comprise
forming a protective film on the metal surface including the at
least one alkyl sulfamic acid or salt thereof.
[0020] The corrosion of any suitable metal surface can be inhibited
using the methods of the invention. Any metal, combination of
metals, or alloys can be protected. Even surfaces that contain
minor amounts or trace amounts of one or metals can be protected.
The metal can be any metal susceptible to corrosion including
industrial metals. Examples of metal surfaces include those
containing one or more of scandium, titanium, vanadium, chromium,
manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium,
platinum, gold, mercury, niobium, iridium, molybdenum, technetium,
ruthenium, rhodium, palladium, silver, cadmium, hafnium, tantalum,
tungsten, rhenium, osmium, aluminum, indium, germanium, gallium,
antimony, tin, lead, bismuth, cerium, praseodymium, neodymium,
promethium, samarium, europium, gadolinium, terbium, dysprosium,
holmium, erbium, thulium, and/or ytterbium and/or alloys of one or
more of these metals. Alloy metals such as stainless steel, steel,
mild steel, bronze, brass, and the like are further examples of
metals. The metal surface can be a ferrous or a non-ferrous
surface. The surface can have any shape and/or dimensions. The
metal surface can be continuous or discontinuous. The metal can be
embedded in one or more non-metal media such as a plastic, a
rubber, a glass, a ceramic, a composite, or the like. The metal can
be electroplated. The metal can be galvanized. A constant or
variable electric current and/or magnetic field can be applied to
the metal surface. The metal surface can be heated or cooled.
[0021] The method of the invention can further include contacting
the metal surface with at least one corrosive agent from which
protection is sought. The applying of the alkyl sulfamic acid, salt
thereof, and/or one or more other anti-corrosive agents can be
performed before, during, and/or after the contacting of the metal
surface with the at least one corrosive agent. The metal surface
can be part of a closed fluid system or an open fluid system, or
both. Examples of systems that can be treated include, but are not
limited to cooling systems, heating systems, cooling towers,
boilers, radiators, steam piping, oil transport machinery and
piping, oil production machinery and piping, paper and pulp
machinery, drinking and tap water treatment plants, plumbing,
sewers, waste water treatment plants, and other industrial uses
that come in contact with corrosive agents.
[0022] An amount effective to inhibit corrosion is an amount that
results in a lower degree of chemical change of the metal surface
in the presence of an anti-corrosion inhibitor than in its absence.
Corrosion inhibition can be partial inhibition or complete
inhibition. The chemical change can be measured, for example, by
measuring a change in weight of the metal surface and/or by
measuring the concentration of metal, ions thereof, or salts
thereof originating from the metal surface in fluid that flows past
the metal surface. The weight loss, for example, of a corrosion
coupon after exposure to a corrosive environment can be expressed
as mils (thousandths of an inch) per year penetration (MPY). The
corrosion rate can be calculated with the assumption of uniform
corrosion over the entire surface of the coupon. MPY can be
calculated by multiplying the weight loss in grams by 22,300 and
then dividing by the product of the area of coupon (sq. in.), the
metal density of the coupon (g/cm.sup.3), and the time of exposure
in a corrosive environment (days). 1 MPY is equal to 0.0254 mm/y,
which is equal to 25.4 .mu.m/y. Accordingly, corrosion rate from
metal loss can be calculated as mm/y=87.6.times.(W/DAT) with W
(weight loss in milligrams), D (metal density in g/cm.sup.3), A
(area of sample in cm.sup.2), and T (time of exposure of the metal
sample in hours).
[0023] Metal corrosion can occur via electrochemical reactions at
the interface between a metal and an electrolyte solution. A thin
film of moisture on a metal surface forms the electrolyte for
atmospheric corrosion. Corrosion normally occurs at a rate
determined by an equilibrium between opposing electrochemical
reactions, anodic (metal oxidation) and cathodic (reduction of a
solution species). These reactions can occur on one metal or on two
or more dissimilar metals that are in electrical communication.
Corrosion current can be used to generate a corrosion rate by
assuming an electrolytic dissolution reaction involving a chemical
species. Uniform corrosion across a metal surface allows
calculation of the corrosion rate in units of distance per year.
For an alloy undergoing uniform dissolution, equivalent weight is a
weighted average of the equivalent weights of the alloy components.
If the dissolution is not uniform, corrosion products can be used
to calculate equivalent weight.
[0024] A weight loss can be converted to a corrosion rate with
knowledge of the density and the sample area of a sample. ASTM
Standard G 102, Standard Practice for Calculation of Corrosion
Rates and Related Information from Electrochemical Measurements can
be used. An eddy current instrument and probe can be used for
measuring corrosion by monitoring a conductivity curve and
impedance plane and using one or more techniques such as single
layer corrosion detection, two layer corrosion detection, a limited
penetration method, dual frequency method, and/or a variable
frequency method.
[0025] The following examples are intended to illustrate, not
limit, the present invention.
EXAMPLES
Example 1
[0026] Copper metal sample coupons with a surface area of 3.38
in.sup.2 were installed in a laboratory-scale liquid recirculating
loop equipped with a reservoir capable of holding approximately 11
L total volume. The apparatus was designed to hold metal sample
coupons in the path of flowing liquid at a chosen flow rate and
temperature for chosen period of time. After exposure for an
adequate period of time, the metal sample weight loss resulting
from corrosion was used to calculate the corrosion rate. The exact
conditions of the tests are listed in the Tables 1-3. For tests
shown in all three tables, the temperature was 35.degree. C.,
linear velocity was 7 gallons per minute (GPM) (3 ft/s), and the
mass of treatment was 10 L. Synthetic water was used having 1170
ppm NaCl and 505 ppm NaHCO.sub.3, at pH 8.
[0027] For the purpose of evaluating yellow-metal corrosion
inhibitor performance, corrosion rate data was generated for the
trial material (hexylsulfamic acid) and a known industry corrosion
inhibitor (tolyltriazole) (identified as "TTA" in the Tables) as a
control, and in some cases untreated (blank) systems, using copper
test coupons in sodium chloride-sodium bicarbonate brine at initial
pH 8.8. This aqueous matrix was designed to mimic the pH,
alkalinity, and total dissolved solids that might be found in a
secondary treated municipal wastewater after four cycles of
concentration. The inhibitor dosage range of from 5 ppm to 10 ppm
was selected because this is an effective dosage range for the
protection of copper with tolytriazole.
[0028] After exposure to the corrosive environment defined by the
testing parameters, corrosion coupons were cleaned with an acidic
solution that is capable of removing various chemical and
biological deposits and films that might have formed on the coupon
surface during exposure to the test environment. The weight change
(and corresponding corrosion rate) determined before a coupon has
been chemically cleaned helps the researcher ascertain general
material removal and/or deposition process information. The
corrosion rate obtained after cleaning is considered the true
corrosion rate for the system under evaluation. Comparative data
from known corrosion inhibitors and/or untreated systems collected
at the time of the subject inhibitor evaluation are advantageous
due to variability in experimental factors that otherwise are not
easily controlled between different experiments. In the tables, the
MPY (milli-inch per year) of corrosion was determined.
[0029] The data presented in Tables 1-3 show that hexylsulfamic
acid has corrosion inhibitor properties that result in copper
corrosion rates far less than that obtained in untreated systems.
The data also show that the copper corrosion inhibition performance
of hexylsulfamic acid is similar to that obtained for
tolyltriazole. The data also show that hexylsulfamic acid
performance as a copper corrosion inhibitor has an inverse
relationship with inhibitor concentration under the given test
conditions, which is similar to the performance trend obtained with
tolyltriazole. Put another way, lower dosages, treatment levels,
were more effective in controlling corrosion than higher
dosages.
TABLE-US-00001 TABLE 1 Inhib- Weight itor Loss/ Dosage Gain Area
Time Treatment Coupon ppm pH grams MPY in.sup.2 hours 5 ppm Copper,
5 8.8 0.0009 0.025 3.38 649 active TTA CDA110 (before cleaning) 5
ppm Copper, 5 8.8 0.0043 0.118 3.38 649 active TTA CDA110 (after
cleaning) 5 ppm Hexyl Copper, 5 8.8 0.0009 0.025 3.38 649 Sulfamic
Acid CDA110 (before cleaning) 5 ppm Hexyl Copper, 5 8.8 0.0043
0.118 3.38 649 Sulfamic Acid CDA110 (after cleaning) 10 ppm Hexyl
Copper, 10 8.8 0.0068 0.186 3.38 649 Sulfamic Acid CDA110 (after
cleaning) 10 ppm Hexyl Copper, 10 8.8 0.0214 0.586 3.38 649
Sulfamic Acid CDA110 (after cleaning)
TABLE-US-00002 TABLE 2 Inhib- Weight itor Loss/ Dosage Gain Area
Time Treatment Coupon ppm pH grams MPY in.sup.2 hours Blank (before
Copper, 0 8.8 0.0086 0.097 3.38 1575 cleaning) CDA110 Blank (after
Copper, 0 8.8 0.0188 0.212 3.38 1575 cleaning) CDA110 5 ppm Copper,
5 8.8 0.0022 0.025 3.38 1575 active TTA CDA110 (before cleaning) 5
ppm Copper, 5 8.8 0.0056 0.063 3.38 1575 active TTA CDA110 (after
cleaning) 10 ppm Hexyl Copper, 10 8.8 0.0044 0.050 3.38 1575
Sulfamic Acid CDA110 (before cleaning) 10 ppm Hexyl Copper, 10 8.8
0.0111 0.125 3.38 1575 Sulfamic Acid CDA110 (after cleaning)
TABLE-US-00003 TABLE 3 Inhib- Weight itor Loss/ Dosage Gain Area
Time Treatment Coupon ppm pH grams MPY in.sup.2 hours 5 ppm Hexyl
Copper, 5 8.8 0.0018 0.174 3.38 184 Sulfamic Acid CDA110 (before
cleaning) 5 ppm Hexyl Copper, 5 8.8 0.0055 0.531 3.38 184 Sulfamic
Acid CDA110 (after cleaning) 7.5 ppm Hexyl Copper, 7.5 8.8 0.0036
0.348 3.38 184 Sulfamic Acid CDA110 (before cleaning) 7.5 ppm Hexyl
Copper, 7.5 8.8 0.0089 0.860 3.38 184 Sulfamic Acid CDA110 (after
cleaning) 10 ppm Hexyl Copper, 10 8.8 0.0033 0.319 3.38 184
Sulfamic Acid CDA110 (before cleaning) 10 ppm Hexyl Copper, 10 8.8
0.0097 0.937 3.38 184 Sulfamic Acid CDA110 (after cleaning)
[0030] The present invention includes the following
aspects/embodiments/features in any order and/or in any
combination:
1. A method of inhibiting corrosion of a metal surface comprising:
applying at least one alkyl sulfamic acid or salt thereof to the
metal surface in an amount effective to inhibit corrosion of the
metal surface. 2. The method of any preceding or following
embodiment/feature/aspect, wherein said alkyl sulfamic acid is a
C.sub.1-C.sub.12 alkyl sulfamic acid or salt thereof. 3. The method
of any preceding or following embodiment/feature/aspect, wherein
the at least one alkyl sulfamic acid has the formula
R.sub.1R.sub.2NS(O).sub.2(OH), and
[0031] R.sub.1 and R.sub.2 are independently a hydrogen, a
C.sub.4-C.sub.20 alkyl group, or a cycloalkyl group, and R.sub.1
and R.sub.2 are not both hydrogen, and/or
[0032] R.sub.1, R.sub.2, and the N form a 5-8 membered heterocyclic
ring including one or more of O, NH, and CH.sub.2.
4. The method of any preceding or following
embodiment/feature/aspect, wherein R.sub.1 and R.sub.2 are
independently a hydrogen, a C.sub.4-C.sub.20 alkyl group, or a
cycloalkyl group, and R.sub.1 and R.sub.2 are not both hydrogen. 5.
The method of any preceding or following embodiment/feature/aspect,
wherein R.sub.1 or R.sub.2, but not both, is a C.sub.4-C.sub.20
alkyl group or a cycloalkyl group. 6. The method of any preceding
or following embodiment/feature/aspect, wherein both R.sub.1 and
R.sub.2 are a C.sub.4-C.sub.20 alkyl group or cycloalkyl group. 7.
The method of any preceding or following embodiment/feature/aspect,
wherein R.sub.1, R.sub.2, and the N form a 5-8 membered
heterocyclic ring including one or more of O, NH, and CH.sub.2. 8.
The method of any preceding or following embodiment/feature/aspect,
wherein the alkyl sulfamic acid or salt thereof is present in a
fluid applied to the metal surface. 9. The method of any preceding
or following embodiment/feature/aspect, wherein the fluid is a
liquid. 10. The method of any preceding or following
embodiment/feature/aspect, wherein the fluid is a vapor. 11. The
method of any preceding or following embodiment/feature/aspect,
wherein the fluid comprises at least one of H.sub.2O, NH.sub.3, and
an alcohol. 12. The method of any preceding or following
embodiment/feature/aspect, wherein the fluid comprises an acid or
base in addition to the alkyl sulfamic acid or salt thereof. 13.
The method of any preceding or following embodiment/feature/aspect,
wherein the fluid comprises a salt solution of at least one salt
independent of the alkyl sulfamic acid salt. 14. The method of any
preceding or following embodiment/feature/aspect, wherein the
applying comprises one or more of flowing, coating, sponging,
wiping, spraying, painting, showering, and misting of the at least
one alkyl sulfamic acid or salt thereof. 15. The method of any
preceding or following embodiment/feature/aspect, wherein the
applying comprises flowing a fluid comprising the at least one
alkyl sulfamic acid or salt thereof over the metal surface. 16. The
method of any preceding or following embodiment/feature/aspect,
wherein the metal surface is a non-ferrous surface. 17. The method
of any preceding or following embodiment/feature/aspect, wherein
the metal surface comprises copper or a copper-containing alloy
(e.g., bronze). 18. The method of any preceding or following
embodiment/feature/aspect, further comprising contacting the metal
surface with at least one corrosive agent. 19. The method of any
preceding or following embodiment/feature/aspect, wherein the
applying is performed before, during, and/or after the contacting.
20. The method of any preceding or following
embodiment/feature/aspect, wherein the metal surface is part of a
closed fluid system.
[0033] The present invention can include any combination of these
various aspects, features, or embodiments above and/or below as set
forth in sentences and/or paragraphs. Any combination of disclosed
features herein is considered part of the present invention and no
limitation is intended with respect to combinable features.
[0034] Applicants specifically incorporate the entire contents of
all cited references in this disclosure. Further, when an amount,
concentration, or other value or parameter is given as either a
range, preferred range, or a list of upper preferable values and
lower preferable values, this is to be understood as specifically
disclosing all ranges formed from any pair of any upper range limit
or preferred value and any lower range limit or preferred value,
regardless of whether ranges are separately disclosed. Where a
range of numerical values is recited herein, unless otherwise
stated, the range is intended to include the endpoints thereof, and
all integers and fractions within the range. It is not intended
that the scope of the invention be limited to the specific values
recited when defining a range.
[0035] It will be apparent to those skilled in the art that various
modifications and variations can be made to the embodiments of the
present invention without departing from the spirit or scope of the
present invention. Thus, it is intended that the present invention
covers other modifications and variations of this invention
provided they come within the scope of the appended claims and
their equivalents.
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