Note: Descriptions are shown in the official language in which they were submitted.
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METHODS FOR INHIBITING CORROSION
Field
The present disclosure relates to methods for identifying a combined corrosion
inhibitor
formulation comprising at least a first and second corrosion inhibitor
formulation for
inhibiting corrosion in various substrates, for example in metal substrates.
The present
disclosure also relates to compositions for inhibiting corrosion comprising a
combined
corrosion inhibitor formulation each independently selected from organic
heterocyclic
compounds and metal salts, metal anions, metal complexes, or any combinations
thereof selected from rare earth, alkali earth and transition metals.
Background
Protection of substrates, such as metal substrates, against atmospheric
corrosion
presents a difficult challenge and has significant economic importance. A
range of
metal substrates requiring protection from corrosion typically include steel,
magnesium
metals, copper, brass, bronze, zinc metals and alloys used for protective
coatings. The
range of fields and applications of particular interest include organic
coatings, flow
systems, coolant systems, air-conditioning systems, shipping, marine, oil and
gas, water
and waste water treatment plants, pipelines and other applications where metal
protection is required.
Corrosion inhibitors are substances that when added in small concentrations to
specific environmental conditions have the ability to reduce the corrosion
rate of metal
exposed to that environment. Corrosion inhibitors can be classified based on
the
chemical nature of the substance, for example organic or inorganic inhibitors;
or by
their mechanism of action, for example anodic inhibitors, cathodic inhibitors
or mixed
inhibitors. As the name suggests, anodic inhibitors cause a large anodic shift
of the
corrosion potential resulting in metal passivation, while the cathodic
inhibitors act by
slowing down the cathodic reaction or precipitate on the cathodic sites to
limit the
diffusion of the reducing species. Mixed inhibitors, in most cases are film
forming
compounds, which reduce both the anodic and cathodic reactions.
Some examples of anodic inhibitors include chromates, nitrates, molybdates.
Examples of cathodic inhibitors include sulphite and bisulphite ions. Examples
of
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mixed inhibitors include silicates and phosphates.
Pigment grade corrosion inhibitors used in organic primers are well known to
require anionic species with inhibitor activity that have limited, but
effective, solubility
in water. For these reasons, chromate based corrosion inhibitor species have
been
preferred in both corrosion control technologies applied on steel for
protection against
atmospheric corrosion, for example provided in conversion coatings and high
performance organic primers. The hexavalent chromate ion has proven to be an
excellent corrosion inhibitor for many metals and alloy systems for almost a
decade.
However, the toxic and carcinogenic nature of the chromate ion has been
understood
for some time and there has been extensive research for almost 30 years for
finding
environmentally acceptable replacements.
It is generally known that if toxicity, efficiency, and price are considered,
the
number of inorganic corrosion inhibitor species available for chromate
replacement is
limited essentially to a few anionic species, including molybdates,
phosphates, borates,
silicates and cyanamides. As a consequence, all commercial non-chromate
corrosion
inhibitor pigments are molybdates, phosphates, borates, silicates or
cyanamides, or
combinations of these compounds. In comparison to chromates, inherent
limitations of
their corrosion preventing mechanism render the anionic species less effective
inhibitors of corrosion, in general, and specifically of atmospheric corrosion
of
aluminium. Consequently, it appears that inorganic chemistry is unable to
produce
inhibitors of atmospheric corrosion, which could be comparably effective, non-
toxic
alternative of the hexavalent chromate.
In contrast, a large array of organic corrosion inhibitors have been more
recently
known and applied in various corrosion control technologies. Excessive
solubility in
water and/or volatility of most of the known organic inhibitors are
limitations when
used in conversion coating technologies and in organic coatings.
Considerable progress has been made with identifying alternative corrosion
inhibitors and the salts of transition metal and rare earth metals offer
possible
alternatives for many applications, including deoxidising and pickling
solutions,
etchants, anodizing and conversion coatings, primer paints and sealants.
Alkali metal
salts of carboxylic acids such as cinnamates have also been found to
effectively inhibit
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the corrosion of mild steel.
Following the work of Mercer et al who demonstrated that the alkali metal
salts
of carboxylic acids such as cinnamates effectively inhibited the corrosion of
mild steel,
Forsyth et al (2002) hypothesised that the combination of the rare earth metal
ions with
an effective organic inhibitor could provide new compounds that suppress both
anodic
and cathodic reactions (i.e. a mixed inhibitor), with a degree of synergy that
would lead
to vastly improved corrosion protection. This was confirmed by Behrouzvaziri
et
al. (2008) and Blin et al. (2007) who showed with electrochemical studies that
lanthanum 4 hydroxy cinnamate provided excellent inhibition of corrosion in
chloride
solutions.
WO 2013/083293 describes a range of polymer coatings for steels substrates
that act as the corrosion inhibitors and reduce the formation of blisters and
filiform
corrosion.
Organic compounds with aromatic character such as carbocyclic and
heterocyclic aromatic structures have also been found to be effective
inhibitors of
corrosion of steel and its alloys, and for example, can be provided with metal
salts or in
the form of a metal complex. For example, Blin et al (2004) relates to
corrosion rate
measurements based on weight loss experiments and linear polarization
resistance
techniques for evaluating the corrosion inhibiting complexes comprising a rare
earth-
based organic complex formed from a rare earth metal and an organic compound
for
the corrosion protection of mild steel.
Several techniques can be used to evaluate the performance of corrosion
inhibitors (V. S. Sastri, 2011). Some of these techniques include mass loss
measurements, salt-spray (fog) test, electrochemical impedance spectroscopy,
potentiodynamic polarisation and polarisation resistance. Many of these
techniques are
either destructive, cannot be monitored as a function of time and do not
provide
tangible and easy to interpret results, whereas, the polarisation resistance
technique is a
non-destructive method that can determine very low corrosion rates accurately,
quickly,
and monitored as a function of time.
Most of the known alternative chromate based corrosion inhibitors suffer from
various problems including poor corrosion inhibiting activity or
incompatibility with
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various coating compositions.
There is a need for identifying alternative corrosion inhibitor compositions
for
the protection of substrates, for example on metal substrates such as steel,
which are
chromate-free corrosion inhibitor compositions.
Summary
Research was undertaken to identify new combined corrosion inhibitor
formulations for protecting various substrates, such as metal substrates, from
corrosion.
It was identified that particular combinations of at least a first and a
second corrosion
inhibitor formulations could be used as improved corrosion inhibitor
compositions. It
was surprisingly found that a combination of at least a first and second
corrosion
inhibitor formulation were advantageously useful as combined corrosion
inhibitor
formulations for inhibiting corrosion on a substrate that could also be
further
advantageously categorised as providing a polarisation value that was greater
than the
sum of the polarisation values for each of the individual corrosion
inhibitors. Further
advantages were identified from combined corrosion inhibitor formulation
comprising
at least two corrosion inhibitors selected from metal salts, metal anions,
metal
complexes, or any combinations thereof, as promoting corrosion protection of
various
substrates. Advantageously, the combined corrosion inhibitor formulations
comprising
at least three corrosion inhibitors were found to further increase the
corrosion
protection of various substrates. The research also identified that combined
corrosion
inhibitor formulations comprising at least four corrosion inhibitors increased
the
corrosion protection of various substrates even further.
In one aspect, there is provided a method of identifying a combined corrosion
inhibitor formulation for inhibiting corrosion of a metal substrate, wherein
the
combined corrosion inhibitor formulation comprises at least a first corrosion
inhibitor
formulation comprising at least one corrosion inhibitor and a second corrosion
inhibitor
formulation comprising at least one corrosion inhibitor that is different to a
corrosion
inhibitor in the first corrosion inhibitor formulation, the method comprising
the steps
of:
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5 independently applying each of the first and second corrosion inhibitor
formulations to the substrate and determining a polarisation resistance value
for each of
the first and second corrosion inhibitor formulations;
combining the first and second corrosion inhibitor formulations together to
provide the combined corrosion inhibitor formulation;
applying the combined corrosion inhibitor formulation to the substrate and
determining a polarisation resistance value for the combined corrosion
inhibitor
formulation, wherein, when said polarisation value for the combined corrosion
inhibitor
formulation is greater than the sum of the polarisation values for each of the
first and
second corrosion inhibitor formulation, said combined corrosion inhibitor
formulation
is categorised as positive.
In an embodiment, there is provided a method of identifying a combined
corrosion inhibitor formulation for inhibiting corrosion of a metal substrate,
wherein
the combined corrosion inhibitor formulation comprises at least a first
corrosion
inhibitor formulation comprising at least one corrosion inhibitor and a second
corrosion
.. inhibitor formulation comprising at least one corrosion inhibitor that is
different to a
corrosion inhibitor in the first corrosion inhibitor formulation, the method
comprising
the steps of:
independently applying each of the first and second corrosion inhibitor
formulations to the substrate and determining a polarisation resistance value
for each of
.. the first and second corrosion inhibitor formulations;
combining the first and second corrosion inhibitor formulations together to
provide the combined corrosion inhibitor formulation;
applying the combined corrosion inhibitor formulation to the substrate and
determining a polarisation resistance value for the combined corrosion
inhibitor
formulation, wherein, when said polarisation value for the combined corrosion
inhibitor
formulation is greater than the sum of the polarisation values for each of the
first and
second corrosion inhibitor formulation, said combined corrosion inhibitor
formulation
is categorised as positive;
wherein the corrosion inhibitors are each independently selected from the
group
consisting of:
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a metal salt, metal anion, metal complex, or any combination thereof, wherein
the metal is selected from the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu,
Gd, Tb,
Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, V, W and Zr; and
an organic heterocyclic compound according to Formula 1:
C=
,----:.:
,
, %)(
1
1 A .
, / x
: I .
, 2,
,........õ,
x' y1
Formula 1
wherein
A is a 5- or 6-membered aryl, heteroaryl or heterocyclic ring, which is
optionally substituted with one or more substituents and optionally fused with
one or
more aryl or heteroaryl rings, wherein a dotted line represents one or more
optional
.. double bonds;
Yi- is selected from S, SH, NH2 or is absent, wherein the dotted line
represents a
double bond when Yi- is S or is absent when Yi- is SH or NH2;
X1-, X2, and X3 are selected from N, NR5, 0, S, CR6 and CR7R8,
R5 is selected from hydrogen, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl,
aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl, aryl or
heteroaryl
group may be optionally substituted, and
R6, R7 and R8, are each independently selected from hydrogen, halogen,
carboxyl, sulphide, thiol, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-Cioalkynyl,
aryl and
heteroaryl, in which each amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl
group may
.. be optionally substituted; and
wherein the combined corrosion inhibitor formulation comprises at least two
corrosion inhibitors selected from metal salts, metal anions, metal complexes,
or any
combinations thereof.
The method of identifying a combined corrosion inhibitor formulation for
.. inhibiting corrosion of a metal substrate, wherein the combined corrosion
inhibitor
formulation comprises: (i) at least two metal salts and at least one organic
heterocyclic
compound of Formula 1 or (ii) at least one metal salt, at least one metal
anion and at
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least one organic heterocyclic compound of Formula 1 or (iii) at least two
metal
complexes, or (iv) at least one metal complex and at least one metal anion.
When the method of identifying the combined corrosion inhibitor formulation is
according to (i), the at least two metal salts are selected from the group
consisting of
Pr3+, Gd3+, Ce3+, Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, and the at least
one organic
heterocyclic compound of formula 1 is selected from the group consisting of 3-
amino-
1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-
thiadiazole,
9H-purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-methy1-2-
mercapto-1,3,4-
thiadiazole.
When the method of identifying the combined corrosion inhibitor formulation is
.. according to (ii), the at least one metal salt is selected from the group
consisting of Pr3+,
Gd3+, Ce3+, Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, the at least one metal
anion is
selected from the group consisting of Mo042-, V043-, Zr042-, W042-, and the at
least
one organic heterocyclic compound of Formula 1 is selected from the group
consisting
of 3-amino-1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-
.. 1,3,4-thiadiazole, 9H-purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-
thiol, and 5-methyl-
2-mercapto-1,3,4-thiadiazole.
When the method of identifying the combined corrosion inhibitor formulation is
according to (iii), the at least two metal complexes are selected from the
group
consisting of zinc molybdate, erbium molybdate, lutetium molybdate, zinc
vanadate,
zinc benzotriazole, dysprosium benzotriazole, lutetium benzotriazole,
gadolinium
benzotriazole, gadolinium molybdate, praseodymium benzimidazole, lutetium
benzimidazole, zinc benzimidazole.
When the method of identifying the combined corrosion inhibitor formulation is
according to (iv), the at least one metal complex is selected from the group
consisting
of zinc molybdate, erbium molybdate, lutetium molybdate, zinc vanadate, zinc
benzotriazole, dysprosium benzotriazole, lutetium benzotriazole, gadolinium
benzotriazole, gadolinium molybdate, praseodymium benzimidazole, lutetium
benzimidazole, zinc benzimidazole, and the at least one metal anion is
selected from
the group consisting of Mo042 , V043, Zr042 , W042 =
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The method of identifying a combined corrosion inhibitor formulation for
inhibiting corrosion of a metal substrate, wherein the combined corrosion
inhibitor
formulation may comprise at least four corrosion inhibitors comprising: (v) at
least two
corrosion inhibitors selected from metal salts and at least two corrosion
inhibitors
selected from organic heterocyclic compounds of Formula 1; or (vi) at least
one metal
salt corrosion inhibitor, at least one metal anion corrosion inhibitor, and at
least two
corrosion inhibitors selected from organic heterocyclic compounds of Formula
1; or
(vii) at least three metal salts, metal anions, metal complexes, or any
combinations
thereof, and at least one corrosion inhibitor selected from an organic
heterocyclic
compound of Formula 1.
When the method of identifying the combined corrosion inhibitor formulation is
according to (v) the at least two metal salts are selected from the group
consisting of
Pr3+, Gd3+, Ce3+, Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, and the at least
two organic
heterocyclic compounds of Formula 1 are selected from the group consisting of
3-
amino-1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-
1,3,4-
thiadiazole, 9H-purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-
methy1-2-
mercapto-1,3,4-thiadiazole.
When the method of identifying the combined corrosion inhibitor formulation is
according to (vi) the at least one metal salt selected from the group
consisting of Pr3+,
Gd3+, Ce3+, Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, the at least one metal
anion
selected from the group consisting of Mo042-, V043-, Zr042-, W042-, and the at
least
two organic heterocyclic compounds of Formula 1 selected from the group
consisting
of 3-amino-1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-
1,3,4-thiadiazole, 9H-purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol,
and 5-methyl-
2-mercapto- 1 ,3 ,4-thiadiazole.
When the method of identifying the combined corrosion inhibitor formulation is
according to (vii) the at least three corrosion inhibitors are selected from
metal salts,
metal anions, metal complexes, or any combinations thereof, selected from the
group
r,
consisting of Pr3+, Gd3+, Ce3+, Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+,
Moki42- Tr\ , v 3-
,
Zr042-, W042-, zinc molybdate, lutetium molybdate, zinc benzotriazole,
lutetium
benzotriazole, gadolinium benzotriazole, gadolinium molybdate, and at least
one
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organic heterocyclic compound of Formula 1 is selected from the group
consisting of 3-
amino-1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-
1,3,4-
thiadiazole.
The combining of the first and second corrosion inhibitor formulations
together
to provide the combined corrosion inhibitor formulation may be based on the
first
.. corrosion inhibitor formulation providing either an immediate inhibitive
response or a
delayed inhibitive response and the second corrosion inhibitor formulation
providing
either an immediate inhibitive response or a delayed inhibitive response.
The combining of the first and second corrosion inhibitor formulations
together
to provide the combined corrosion inhibitor formulation may be based on the
first
corrosion inhibitor formulation providing a delayed inhibitive response and
the second
corrosion inhibitor formulation providing an immediate inhibitive response.
The immediate inhibitive response may be provided by an instantaneous
corrosion inhibitor and a delayed inhibitive response may be provided by a
film-
forming inhibitor.
When the first corrosion inhibitor formulation comprises a corrosion inhibitor
providing a delayed inhibitive response and the second corrosion inhibitor
formulation
comprises a corrosion inhibitor providing an immediate inhibitive response,
the
polarisation response for the combined corrosion inhibitor formulation
polarisation
resistance response may be a continuous inhibitive response.
The corrosion inhibitors may be each independently selected from the group
consisting of:
a metal salt, metal anion, metal complex, or any combination thereof, wherein
the metal is selected from the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu,
Gd, Tb,
Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, V, W and Zr; and
an organic heterocyclic compound according to Formula 1:
;C
,--- ----
1 A i I
.
,
,
1
2
/ x2,
,......0
X3 y1
Formula 1
wherein
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5 A is a 5- or 6-membered aryl, heteroaryl or heterocyclic ring, which is
optionally substituted with one or more substituents and optionally fused with
one or
more aryl or heteroaryl rings, wherein a dotted line represents one or more
optional
double bonds;
is selected from S, SH, NH2 or is absent, wherein the dotted line represents a
10 double bond when is S or is absent when is SH or NH2;
X1-, X2, and X3 are selected from N, NR5, 0, S, CR6 and CR7R8,
R5 is selected from hydrogen, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl,
aryl or
heteroaryl group may be optionally substituted, and
R6, R7 and R8, are each independently selected from hydrogen, halogen,
carboxyl, sulphide, thiol, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-Cioalkynyl,
aryl and
heteroaryl, in which each amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl
group may
be optionally substituted.
For the organic heterocyclic compounds of Formula 1, R6, R7 and R8, are each
independently selected from hydrogen, halogen, carboxyl, amino, Ci-Cioalkyl,
C2-
Cioalkenyl, C2-Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl,
alkenyl,
alkynyl, aryl or heteroaryl group may be optionally substituted.
The metals may be selected from at least one of Zn, Mo, Sm, Dy, Tb, Pr, Er,
Tm, Lu and Gd.
The substrate may be a metal substrate. It will be appreciated that the metal
substrate can include any substrate material having at least a portion of its
surface being
metallic. The metal substrate may comprise any metal requiring protection from
corrosion. The metal substrate may be of steel, zinc, magnesium, copper, brass
and
bronze. The metal substrate may be a steel substrate.
In another aspect there is provided a combined corrosion inhibitor formulation
prepared according to the method described herein.
In another aspect there is provided a combined corrosion inhibitor formulation
for inhibiting corrosion of a metal substrate, wherein the combined corrosion
inhibitor
formulation comprises at least a first corrosion inhibitor formulation
comprising at least
one corrosion inhibitor and a second corrosion inhibitor formulation
comprising at least
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one corrosion inhibitor that is different to a corrosion inhibitor in the
first corrosion
inhibitor formulation;
wherein the corrosion inhibitors are each independently selected from the
group
consisting of:
a metal salt, metal anion, metal complex, or any combination thereof, wherein
the metal is selected from the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu,
Gd, Tb,
Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, V, W and Zr; and
an organic heterocyclic compound according to Formula 1:
7----µs% X1
A
I
r"
y1
X3
Formula 1
wherein
A is a 5- or 6-membered aryl, heteroaryl or heterocyclic ring, which is
optionally substituted with one or more substituents and optionally fused with
one or
more aryl or heteroaryl rings, wherein a dotted line represents one or more
optional
double bonds;
Y is selected from S, SH, NH2 or is absent, wherein the dotted line represents
a
double bond when is S or is absent when is SH or NH2;
X1-, X2, and X3 are selected from N, NR5, 0, S, CR6 and CR7R8,
R5 is selected from hydrogen, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl,
aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl, aryl or
heteroaryl
group may be optionally substituted, and
R6, R7 and R8, are each independently selected from hydrogen, halogen,
carboxyl, sulphide, thiol, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-Cioalkynyl,
aryl and
heteroaryl, in which each amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl
group may
be optionally substituted; and
wherein the combined corrosion inhibitor formulation comprises: (i) at least
two
metal salts and at least one organic heterocyclic compound of Formula 1 or
(ii) at least
one metal salt, at least one metal anion and at least one organic heterocyclic
compound
of Formula 1 or (iii) at least two metal complexes, or (iv) at least one metal
complex
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and at least one metal anion; or (v) at least two corrosion inhibitors
selected from metal
salts and at least two corrosion inhibitors selected from organic heterocyclic
compounds of Formula 1; or (vi) at least one metal salt corrosion inhibitor,
at least one
metal anion corrosion inhibitor, and at least two corrosion inhibitors
selected from
organic heterocyclic compounds of Formula 1; or (vii) at least three metal
salts, metal
anions, metal complexes, or any combinations thereof, and at least one
corrosion
inhibitor selected from an organic heterocyclic compound of Formula 1.
When the combined corrosion inhibitor formulation is according to (i), the at
least two metal salts are selected from the group consisting of Pr3+, Gd3+,
Ce3+, Dy3+,
Sm3+, Er3+, Lu3+, Zn2-h, Co2-h, Cu2-h, and the at least one organic
heterocyclic compound
of formula 1 is selected from the group consisting of 3-amino-1,2,4-triazole,
benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-thiadiazole, 9H-
purine-8-
thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-methy1-2-mercapto-1,3,4-
thiadiazole.
When the combined corrosion inhibitor formulation is according to (ii), the at
3+ least one metal salt is selected from the group consisting of Pr, Gd3+ ,
Ce3+ , Dy3+ ,
Sm3+, Er3+, Lu3+, Zn2, Co2, Cu2-', the at least one metal anion is selected
from the
group consisting of Mo042-, V043-, ZrO42 , W042-, and the at least one organic
heterocyclic compound of Formula 1 is selected from the group consisting of 3-
amino-
1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-
thiadiazole,
9H-purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-methy1-2-
mercapto-1,3,4-
thiadiazole.
When the combined corrosion inhibitor formulation is according to (iii), the
at
least two metal complexes are selected from the group consisting of zinc
molybdate,
erbium molybdate, lutetium molybdate, zinc vanadate, zinc benzotriazole,
dysprosium
benzotriazole, lutetium benzotriazole, gadolinium benzotriazole, gadolinium
molybdate, praseodymium benzimidazole, lutetium benzimidazole, zinc
benzimidazole.
When the combined corrosion inhibitor formulation is according to (iv), the at
least one metal complex is selected from the group consisting of zinc
molybdate,
erbium molybdate, lutetium molybdate, zinc vanadate, zinc benzotriazole,
dysprosium
benzotriazole, lutetium benzotriazole, gadolinium benzotriazole, gadolinium
molybdate, praseodymium benzimidazole, lutetium benzimidazole, zinc
benzimidazole,
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and the at least one metal anion is selected from the group consisting of
Mo042-, V043-,
Zr042 , W042 =
When the combined corrosion inhibitor formulation is according to (v) the at
least two metal salts are selected from the group consisting of Pr3+, Gd3+,
Ce3+, Dy3+,
Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, and the at least two organic heterocyclic
compounds
of Formula 1 are selected from the group consisting of 3-amino-1,2,4-triazole,
benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-thiadiazole, 9H-
purine-8-
thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-methy1-2-mercapto-1,3,4-
thiadiazole.
When the combined corrosion inhibitor formulation is according to (vi) the at
least one metal salt selected from the group consisting of Pr3+, Gd3+, Ce3+,
Dy3+, Sm3+,
.. Er3+, Lu3+, Zn2+, Co2+, Cu2+, the at least one metal anion selected from
the group
consisting of Mo042-, V043-, ZrO2, W042-, and the at least two organic
heterocyclic
compounds of Formula 1 selected from the group consisting of 3-amino-1,2,4-
triazole,
benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-thiadiazole, 9H-
purine-8-
thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-methy1-2-mercapto-1,3,4-
thiadiazole.
When the combined corrosion inhibitor formulation is according to (vii) the at
least three corrosion inhibitors are selected from metal salts, metal anions,
metal
complexes, or any combinations thereof, selected from the group consisting of
Pr3+,
Gd3+, Ce3+, Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, Mo042-, V043-, ZrO2,
W042-,
zinc molybdate, lutetium molybdate, zinc benzotriazole, lutetium
benzotriazole,
gadolinium benzotriazole, gadolinium molybdate, and at least one organic
heterocyclic
compound of Formula 1 is selected from the group consisting of 3-amino-1,2,4-
triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-
thiadiazole.
It will be appreciated by persons skilled in the art that numerous variations
and/or modifications may be made to the above-described embodiments, without
departing from the broad general scope of the present disclosure. The present
embodiments are, therefore, to be considered in all respects as illustrative
and not
restrictive.
Brief Description of the Figures
Some embodiments of the present disclosure are described and illustrated
herein, by way of example only, with reference to the accompanying Figures in
which:
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Figure 1 is a graph showing polarisation resistance electrochemical
experiments performed on mild steel for a selection of metal salt corrosion
inhibitors
and their combination.
Figure 2 is a graph showing polarisation resistance electrochemical
experiments performed on mild steel for a selection of metal salt corrosion
inhibitors
and their combination.
Figure 3 is a graph showing polarisation resistance electrochemical
experiments performed on mild steel for a selection of metal salt corrosion
inhibitors
and their combination.
Figure 4 is a graph showing polarisation resistance electrochemical
experiments performed on mild steel for a selection of corrosion inhibitors
selected
from metal salts, organic heterocyclic compounds and their combination.
Figure 5 is a graph showing polarisation resistance electrochemical
experiments performed on mild steel for 1:1:1 combined corrosion inhibitor
formulations selected from a combination of metal salt, metal anion and
organic
heterocyclic compounds.
Figure 6 is a graph showing polarisation resistance electrochemical
experiments performed on mild steel for 1:1:1:1 combined corrosion inhibitor
formulations selected from a combination of metal salt, metal anion and
organic
heterocyclic compounds.
Description of Embodiments
The present disclosure describes the following various non-limiting examples,
which relate to investigations undertaken to identify alternative chromate
free corrosion
inhibitors. It was surprisingly found that a combined corrosion inhibitor
formulation
comprising at least a first and second corrosion inhibitor formulation were
advantageously useful as corrosion inhibiting combinations for inhibiting
corrosion on
a substrate that could also be further advantageously categorised as providing
a
polarisation value that was greater than the sum of the polarisation values
for each of
the individual corrosion inhibitors. The combined corrosion inhibitor
formulations
comprising at least two corrosion inhibitors selected from metal salts, metal
anions,
metal complexes, or any combinations thereof, of at least some embodiments or
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5 examples as described herein provide an advantage of further promoting
corrosion
protection of various substrates. In some embodiments, the combined corrosion
inhibitor formulations comprise at least three corrosion inhibitors. One
advantage of the
combined corrosion inhibitors comprising at least three corrosion inhibitors
of the
present disclosure, at least according to some embodiments or examples as
described
10 herein, is that they can further enhance the corrosion inhibition on a
substrate. In
another embodiment, the combined corrosion inhibitor formulations may comprise
at
least four corrosion inhibitors. The combined corrosion inhibitors comprising
at least
four corrosion inhibitors of the present disclosure, at least according to
some
embodiments or examples as described herein, can advantageously increase the
15 corrosion protection of various substrates even further.
GENERAL TERMS
As used herein, the term "substrate" refers to any structure that may require
protection from corrosion and that can be cleaned and/or protected and/or
modified to
provide unique properties. The substrate may comprise at least a portion of
its surface
being metallic or being of any other material susceptible to corrosion. The
substrate
may be a metal substrate.
As used herein, the term "metal substrate" refers to a structure having at
least a
portion of its surface being metallic that can be cleaned and/or protected
and/or
modified to provide unique properties. A "metal substrate" is not limited to
any
particular type of metallic surface, and in terms of applying a corrosion
inhibiting
coating, such metal substrates typically include zinc, magnesium, copper,
brass, bronze,
and steel, for example mild steel, carbon steel, stainless steel, high
strength/low allow
steel, galvanised steel, or galfan steel.
As used herein, the term "protective composition" refers to any composition
suitable for use in providing some form of corrosion protection to a
substrate. For
example, a protective composition can include a powder coating composition for
use in
protecting steel from corrosion, or a film-forming organic polymer based
composition
for protecting steel from corrosion.
As used herein, the term "extender" or "extender pigment" when used without
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qualification, refers to a type of pigment that is typically incorporated into
a paint
formulation to provide volume to the final resulting coating after paint
curing, although
it can be added for other reasons, such as to reduce cost. An extender can
additionally
or alternatively be an active component in making a total system more
corrosion
resistant. Extenders which add volume are often referred to as "fillers" or
"extenders/fillers."
As used herein, the term "coating" refers to a polymeric material (organic or
inorganic) that can be applied either as a liquid (e.g., paint) or solid
(e.g., powder) to a
substrate to form a polymeric film. Such polymeric materials include, but are
not
limited to, powder coatings, paints, sealants, conducting polymers, sol gels
(e.g.
BoegelTM made by Boeing Co. having offices in Chicago, Ill.), silicates,
silicones,
zirconates, titanates, and the like. A "coating" is comprised of a complex
mixture of
binders, solvents, pigments and additives. Many coatings have one or more
substances
from each of the four categories. Coating properties, such as gloss and color,
are related
to the film surface, for example as a two-dimensional entity. However, the
bulk
properties of a coating are related to its three-dimensional structure. Phase
continuity is
a volume concept, and the coating performance is dependent on the integrity of
the
binder phase.
As used herein, the term "film-forming organic polymer" or "film-forming
polymeric material" refers to any polymeric material that can be used to make
coatings,
including monomers, co-monomers, resins or polymers. The polymeric material
can
also be referred to as a "binder", and can be either organic or inorganic. The
organic
polymeric material generally has a carbon backbone and the inorganic polymeric
material generally has a silicone backbone. Organic binders are made up of
organic
monomers and oligomers from which the binders generally derive their names.
Examples of these would be acrylic, epoxy, urethane, melamine, and so forth.
Binders
include epoxy-based resin binders such as a water reducible epoxy-polyamide
system
(for organic polymeric materials) or non-epoxy-based resin binders such as
urethanes,
ureas, acrylates, alkyds, melamines, polyesters, vinyls, vinyl esters,
silicones, siloxanes,
silicates, sulfides, silicate polymers, epoxy novolacs, epoxy phenolics,
drying oils,
hydrocarbon polymers, and the like.
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As used herein, the term "weight percent (wt %)" when used without
qualification, typically refers to the weight percent of a particular solid
component, e.g.,
pigment, extender, etc., as compared with all solid components present,
excluding
polymeric resins. For example, if the only solid component present in the
coating is a
corrosion-inhibiting carbon pigment, the corrosion-inhibiting carbon pigment
is
considered to have a wt % of 100.
Throughout this specification the word "comprise", or variations such as
"comprises" or "comprising", will be understood to imply the inclusion of a
stated
element, integer or step, or group of elements, integers or steps, but not the
exclusion of
any other element, integer or step, or group of elements, integers or steps.
The various
embodiments disclosed and described in this specification can comprise,
consist of, or
consist essentially of the features and characteristics as variously described
herein. The
word "comprise", "comprises", or "comprising" includes those embodiments that
"consist of' or "consist essentially of' the features and characteristics as
variously
described.
Any discussion of documents, acts, materials, devices, articles or the like
which
has been included in the present specification is solely for the purpose of
providing a
context for the present disclosure. It is not to be taken as an admission that
any or all of
these matters form part of the prior art base or were common general knowledge
in the
field relevant to the present disclosure as it existed before the priority
date of each
claim of this application.
CHEMICAL TERMS
As will be understood, an aromatic group means a cyclic group having 4 m+2
electrons, where m is an integer equal to or greater than 1. As used herein,
"aromatic" is
used interchangeably with "aryl" to refer to an aromatic group, regardless of
the
valency of aromatic group. Thus, aryl refers to monovalent aromatic groups,
bivalent
aromatic groups and higher multivalency aromatic groups.
The term "joined" refers to a ring, moiety or group that is joined to at least
one
other ring, moiety or group by a single covalent bond.
The term "fused" refers to one or more rings that share at least two common
ring atoms with one or more other rings.
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A heteroaromatic group is an aromatic group or ring containing one or more
heteroatoms, such as N, 0, S, Se, Si or P. As used herein, "heteroaromatic" is
used
interchangeably with "heteroaryl", and a heteroaryl group refers to monovalent
aromatic groups, bivalent aromatic groups and higher multivalency aromatic
groups
containing one or more heteroatoms.
The term "optionally substituted" means that a group is either substituted or
unsubstituted, at any available position. Substitution can be with one or more
groups
selected from, e.g., alkyl, alkenyl, alkynyl, cycloallcyl, cycloalkenyl, aryl,
heterocyclyl,
heteroaryl, formyl, allcanoyl, cycloallcanoyl, aroyl, heteroaroyl, carboxyl,
alkoxycarbonyl, cycloalkyloxycarbonyl, aryloxycarbonyl,
heterocyclyloxycarbonyl,
heteroaryloxycarbonyl, alkylaminocarbonyl, cycloallcylaminocarbonyl,
arylaminocarbonyl, heterocyclylaminocarbonyl, heteroarylaminocarbonyl, cyano,
alkoxy, cycloalkoxy, aryloxy, heterocyclyloxy, heteroaryloxy, alkanoate,
cycloalkanoate, aryloate, heterocyclyloate, heteroaryloate,
alkylcarbonylamino,
cycloalkylcarbonylamino, arylcarbonylamino, heterocyclylcarbonylamino,
heteroarylcarbonylamino, nitro, hydroxyl, halogen, haloalkyl, haloaryl,
haloheterocyclyl, haloheteroaryl, haloalkoxy, silylalkyl, alkenylsilylallcyl,
alkynylsilylalkyl, and amino. The optional substitution may be one or more
groups
selected from halogen, alkyl, formyl, and amino. The optional substituents may
include
salts of the groups, for example carboxylate salts. It will be appreciated
that other
groups not specifically described may also be used.
"Alkyl" whether used alone, or in compound words such as alkoxy, alkylthio,
alkylamino, dialkylamino or haloalkyl, represents straight or branched chain
hydrocarbons ranging in size from one to about 10 carbon atoms, or more. Thus
alkyl
moieties include, unless explicitly limited to smaller groups, moieties
ranging in size,
for example, from one to about 6 carbon atoms or greater, such as, methyl,
ethyl, n-
propyl, iso-propyl and/or butyl, pentyl, hexyl, and higher isomers, including,
e.g., those
straight or branched chain hydrocarbons ranging in size from about 6 to about
10
carbon atoms, or greater.
"Alkenyl" whether used alone, or in compound words such as alkenyloxy or
haloallcenyl, represents straight or branched chain hydrocarbons containing at
least one
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carbon-carbon double bond, including, unless explicitly limited to smaller
groups,
moieties ranging in size from two to about 6 carbon atoms or greater, such as,
methylene, ethylene, 1-propenyl, 2-propenyl, and/or butenyl, pentenyl,
hexenyl, and
higher isomers, including, e.g., those straight or branched chain hydrocarbons
ranging
in size, for example, from about 6 to about 10 carbon atoms, or greater.
"Alkynyl" whether used alone, or in compound words such as alkynyloxy,
represents straight or branched chain hydrocarbons containing at least one
carbon-
carbon triple bond, including, unless explicitly limited to smaller groups,
moieties
ranging in size from, e.g., two to about 6 carbon atoms or greater, such as,
ethynyl, 1-
propynyl, 2-propynyl, and/or butynyl, pentynyl, hexynyl, and higher isomers,
including, e.g., those straight or branched chain hydrocarbons ranging in size
from,
e.g., about 6 to about 10 carbon atoms, or greater.
"Cycloalkyl" represents a mono- or polycarbocyclic ring system of varying
sizes, e.g., from about 3 to about 10 carbon atoms, e.g., cyclopropyl,
cyclobutyl,
cyclopentyl, cyclohexyl or cycloheptyl. The term cycloalkyloxy represents the
same
groups linked through an oxygen atom such as cyclopentyloxy and cyclohexyloxy.
The
term cycloalkylthio represents the same groups linked through a sulfur atom
such as
cyclopentylthio and cyclohexylthio.
"Cycloalkenyl" represents a non-aromatic mono- or polycarbocyclic ring system,
e.g., of about 3 to about 10 carbon atoms containing at least one carbon-
carbon double
bond, e.g., cyclopentenyl, cyclohexenyl or cycloheptenyl. The term
"cycloalkenyloxy"
represents the same groups linked through an oxygen atom such as
cyclopentenyloxy and
cyclohexenyloxy. The term "cycloalkenylthio" represents the same groups linked
through
a sulfur atom such as cyclopentenylthio and cyclohexenylthio.
The terms, "carbocyclic" and "carbocycly1" represent a ring system wherein the
ring atoms are all carbon atoms, e.g., of about 3 to about 10 carbon atoms,
and which
may be aromatic, non-aromatic, saturated, or unsaturated, and may be
substituted
and/or carry fused rings. Examples of such groups include benzene,
cyclopentyl,
cyclohexyl, or fully or partially hydrogenated phenyl, naphthyl and fluorenyl.
"Aryl" whether used alone, or in compound words such as arylalkyl, aryloxy or
arylthio, represents: (i) an optionally substituted mono- or polycyclic
aromatic
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phenyl, naphthyl
or fluorenyl; or, (ii) an optionally substituted partially saturated
polycyclic carbocyclic
aromatic ring system in which an aryl and a cycloalkyl or cycloallcenyl group
are fused
together to form a cyclic structure such as a tetrahydronaphthyl, indenyl
,indanyl or
fluorene ring.
10 "Heterocycly1" or "heterocyclic" whether used alone, or in compound
words
such as heterocyclyloxy represents: (i) an optionally substituted cycloalkyl
or
cycloalkenyl group, e.g., of about 3 to about 60 ring members, which may
contain one
or more heteroatoms such as nitrogen, oxygen, or sulfur (examples include
pyrrolidinyl, morpholino, thiomorpholino, or fully or partially hydrogenated
thienyl,
15 furyl, pyrrolyl, thiazolyl, oxazolyl, oxazinyl, thiazinyl, pyridyl and
azepinyl); (ii) an
optionally substituted partially saturated polycyclic ring system in which an
aryl (or
heteroaryl) ring and a heterocyclic group are fused together to form a cyclic
structure
(examples include chromanyl, dihydrobenzofuryl and indolinyl); or (iii) an
optionally
substituted fully or partially saturated polycyclic fused ring system that has
one or more
20 bridges (examples include quinuclidinyl and dihydro-1,4-epoxynaphthyl).
"Heteroaryl" or "hetaryl" whether used alone, or in compound words such as
heteroaryloxy represents: (i) an optionally substituted mono- or polycyclic
aromatic
organic moiety, e.g., of about 1 to about 10 ring members in which one or more
of the
ring members is/are element(s) other than carbon, for example nitrogen,
oxygen, sulfur
or silicon; the heteroatom(s) interrupting a carbocyclic ring structure and
having a
sufficient number of delocalized pi electrons to provide aromatic character,
provided
that the rings do not contain adjacent oxygen and/or sulfur atoms. Typical 6-
membered
heteroaryl groups are pyrazinyl, pyridazinyl, pyrazolyl, pyridyl and
pyrimidinyl. All
regioisomers are contemplated, e.g., 2-pyridyl, 3-pyridyl and 4-pyridyl.
Typical 5-
membered heteroaryl rings are furyl, imidazolyl, oxazolyl, isoxazolyl,
isothiazolyl,
oxadiazolyl, pyrrolyl, 1,3,4-thiadiazolyl, thiazolyl, thienyl, triazolyl, and
silole. All
regioisomers are contemplated, e.g., 2-thienyl and 3-thienyl. Bicyclic groups
typically
are benzo-fused ring systems derived from the heteroaryl groups named above,
e.g.,
benzofuryl, benzimidazolyl, benzthiazolyl, indolyl, indolizinyl, isoquinolyl,
quinazolinyl, quinolyl and benzothienyl; or, (ii) an optionally substituted
partially
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saturated polycyclic heteroaryl ring system in which a heteroaryl and a
cycloalkyl or
cycloalkenyl group are fused together to form a cyclic structure such as a
tetrahydroquinolyl or pyrindinyl ring.
"Formyl" represents a -CHO moiety.
"Alkanoyl" represents a -C(=0)-alkyl group in which the alkyl group is as
.. defined supra. An alkanoyl group may range in size from about C2-C20. One
example is
acyl.
"Aroyl" represents a -C(=0)-aryl group in which the aryl group is as defined
supra. An aroyl group may range in size from about C7-C20. Examples include
benzoyl
and 1-naphthoyl and 2-naphthoyl.
"Heterocycloyl" represents a -C(=0)-heterocycly1 group in which the
heterocylic group is as defined supra. An heterocycloyl may range in size from
about
C4-C20.
"Heteroaroyl" represents a -C(=0)-heteroaryl group in which the heteroaryl
group is as defined supra. A heteroaroyl group may range in size from about C6-
C20. An
example is pyridylcarbonyl.
"Carboxyl" represents a -CO2H moiety.
"Oxycarbonyl" represents a carboxylic acid ester group -CO2R which is linked
to the rest of the molecule through a carbon atom.
"Alkoxycarbonyl" represents an -0O2-alkyl group in which the alkyl group is as
defined supra. An alkoxycarbonyl group may range in size from about C2-C20.
Examples include methoxycarbonyl and ethoxycarbonyl.
"Aryloxycarbonyl" represents an -0O2-aryl group in which the aryl group is as
defined supra. Examples include phenoxycarbonyl and naphthoxycarbonyl.
"Heterocyclyloxycarbonyl" represents a -0O2-heterocycly1 group in which the
heterocyclic group is as defined supra.
"Heteroaryloxycarbonyl" represents a -0O2-heteroaryl group in which the
heteroaryl group is as defined supra.
"Aminocarbonyl" represents a carboxylic acid amide group -C(=0)NHR or -
C(=0)NR2 which is linked to the rest of the molecule through a carbon atom.
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"Alkylaminocarbonyl" represents a -C(=0)NHR or -C(=0)NR2 group in which
R is an alkyl group as defined supra.
"Arylaminocarbonyl" represents a -C(=0)NHR or -C(=0)NR2 group in which R
is an aryl group as defined supra.
"Heterocyclylaminocarbonyl" represents a -C(=0)NHR or -C(=0)NR2 group in
which R is a heterocyclic group as defined supra. NR2 may for example be a
heterocyclic ring, which is optionally substituted.
"Heteroarylaminocarbonyl" represents a -C(=0)NHR or -C(=0)NR2 group in
which R is a heteroaryl group as defined supra. NR2 may for example be a
heteroaryl
ring, which is optionally substituted.
"Cyano" represents a -CN moiety.
"Hydroxyl" represents a -OH moiety.
"Alkoxy" represents an -0-alkyl group in which the alkyl group is as defined
supra. Examples include methoxy, ethoxy, n-propoxy, iso-propoxy, and the
different
butoxy, pentoxy, hexyloxy and higher isomers.
"Aryloxy" represents an -0-aryl group in which the aryl group is as defined
supra. Examples include, without limitation, phenoxy and naphthoxy.
"Alkenyloxy" represents an -0-alkenyl group in which the alkenyl group is as
defined supra. An example is allyloxy.
"Heterocyclyloxy" represents an -0-heterocycly1 group in which the
heterocyclic group is as defined supra.
"Heteroaryloxy" represents an -0-heteroaryl group in which the heteroaryl
group is as defined supra. An example is pyridyloxy.
"Alkanoate" represents an -0C(=0)-R group in which R is an alkyl group as
defined supra.
"Aryloate" represents a -0C(=0)-R group in which R is an aryl group as
defined supra.
"Heterocyclyloate" represents an -0C(=0)--R group in which R is a
heterocyclic group as defined supra.
"Heteroaryloate" represents an -0C(=0)-R group in which R is a heteroaryl
group as defined supra.
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"Amino" represents an -NH2 moiety.
"Alkylamino" represents an -NHR or -NR2 group in which R is an alkyl group
as defined supra. Examples include, without limitation, methylamino,
ethylamino, n-
propylamino, isopropylamino, and the different butylamino, pentylamino,
hexylamino
and higher isomers.
"Arylamino" represents an -NHR or -NR2 group in which R is an aryl group as
defined supra. An example is phenylamino.
"Heterocyclylamino" represents an -NHR or -NR2 group in which R is a
heterocyclic group as defined supra. NR2 may for example be a heterocyclic
ring,
which is optionally substituted.
"Heteroarylamino" represents a -NHR or -NR2 group in which R is a heteroaryl
group as defined supra. NR2 may for example be a heteroaryl ring, which is
optionally
substituted.
"Carbonylamino" represents a carboxylic acid amide group -NHC(=0)R that is
linked to the rest of the molecule through a nitrogen atom.
"Alkylcarbonylamino" represents a -NHC(=0)R group in which R is an alkyl
group as defined supra.
"Arylcarbonylamino" represents an -NHC(=0)R group in which R is an aryl
group as defined supra.
"Heterocyclylcarbonylamino" represents an -NHC(=0)R group in which R is a
heterocyclic group as defined supra.
"Heteroarylcarbonylamino" represents an -NHC(=0)R group in which R is a
heteroaryl group as defined supra.
"Nitro" represents a -NO2 moiety.
"Aldehyde" represents a ¨C(=0)H group.
"Alkanal" represents an alkyl-(C=0)H group in which the alkyl group is as
defined supra.
"Alkylsily1" represents an alkyl group that is linked to the rest of the
molecule
through the silicon atom, which may be substituted with up to three
independently
selected alkyl groups in which each alkyl group is as defined supra.
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"Alkenylsily1" presents an alkenyl group that is linked to the rest of the
molecule through the silicon atom, which may be substituted with up to three
independently selected alkenyl groups in which each alkenyl group is as
defined supra.
"Alkynylsily1" presents an alkynyl group that is linked to the rest of the
molecule through the silicon atom, which may be substituted with up to three
independently selected alkynyl groups in which each alkenyl group is as
defined supra.
The term "halo" or "halogen" whether employed alone or in compound words
such as haloalkyl, haloalkoxy or haloalkylsulfonyl, represents fluorine,
chlorine,
bromine or iodine. Further, when used in compound words such as haloalkyl,
haloalkoxy or haloalkylsulfonyl, the alkyl may be partially halogenated or
fully
substituted with halogen atoms which may be independently the same or
different.
Examples of haloalkyl include, without limitation, -CH2CH2F, -CF2CF3 and -
CH2CHFC1. Examples of haloalkoxy include, without limitation, -OCHF2, -0CF3, -
0CH2CC13, -OCH2CF3 and -OCH2CH2CF3. Examples of haloalkylsulfonyl include,
without limitation, -S02CF3, -S02CC13, -S02CH2CF3 and -S02CF2CF3.
The terms "thiol", "thio", "mercapto" or "mercaptan" refer to any
organosulphur group containing a sulphurhydryl moiety ¨SH, which includes a R-
SH
group where R is a moiety containing a carbon atom for coordination to the ¨SH
moiety, for example an alkylsulphur group as defined supra. For example, the
thiol or
mercapto group may be a sulphurhydryl moiety ¨SH.
The terms "thione", "thioketones" or "thiocarbonyls" refer to any
organosulphur group containing a ¨C=S moiety, which includes a R-C=S group,
for
example where R is an alky group defined supra. For example, the thione group
may be
a ¨C=S moiety.
The term "exocyclic" refers to an atom or group that is attached externally to
a
.. cyclic ring system of a heteroaryl or heterocyclic compound, which
contrasts with an
"endocyclic" atom or group that is within the ring system such that the atoms
form a
part of the ring system of the heteroaryl or heterocyclic compound.
The compounds described herein may include salts, solvates, hydrates, isomers,
tautomers, racemates, stereoisomers, enantiomers or diastereoisomers of those
compounds. For example salts may include sodium, potassium, calcium, nitrates,
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5 phosphates, sulphates, molybdates, and chlorides. In one embodiment the
compounds
include salts thereof selected from sodium salts.
ORGANIC HETEROCYCLIC COMPOUND
The corrosion inhibitors of the present disclosure may be selected from an
organic heterocyclic compound. The organic heterocyclic compounds may be each
10 optionally substituted and optionally fused with one or more
substituents or groups.
The organic heterocyclic compounds may be selected from an optionally
substituted,
optionally fused, heteroaryl or heterocyclic compound. The organic
heterocyclic
compound may include salts, for example, thiol sodium salt.
The one or more organic heterocyclic compounds may each be selected from an
15 optionally substituted, optionally fused, 5 or 6-membered mono or
bicyclic heteroaryl
or heterocyclic compound.
The organic heterocyclic compound may be selected from a compound of
Formula 1 or salt thereof:
A ; I
µ,. x2,
-1
20 Formula 1
wherein
A is a 5- or 6-membered aryl, heteroaryl or heterocyclic ring, which is
optionally substituted with one or more substituents and optionally fused with
one or
more aryl or heteroaryl rings, wherein a dotted line represents one or more
optional
25 double bonds,
Yl is selected from S, SH, NH2 or is absent, wherein the dotted line
represents a
double bond when Yl is S or is absent when Yl is SH or NH2,
Xl, X2, and X3 are selected from N, NR5, 0, S, CR6 and CR7R8,
R5 is selected from hydrogen, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl,
aryl or
heteroaryl group may be optionally substituted, and
R6, R7 and R8, are each independently selected from hydrogen, halogen,
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carboxyl, sulphide, thiol, amino, Ci-Cioalkyl, C2-Cioalkenyl, C2-Cioalkynyl,
aryl and
heteroaryl, in which each amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl
group may
be optionally substituted.
For the organic heterocyclic compounds of Formula 1, Yl may be absent. Xl
and X2 may be selected from N, NH, and S. Xl and X2 may be selected from N and
S.
Xl and X2 may be selected from N and NH. X3 may be selected from N, NH, 0, and
S.
X3 may be selected from N, NH, and S. X3 may be selected from N and NH. Xl, X2
and
X3 may be each independently selected from N, NH and S. Xl, X2 and X3 may be
each
independently selected from N and NH. Xl and X2 may be each independently
selected
from N and NH. Xl and X3 may be selected from N and NH, and X2 may be selected
from CR6 and CR7R8.
For the organic heterocyclic compounds of Formula 1, Yl may be absent. Xl
and X2 may each be independently selected from N, NH, and S. Xl may be further
selected from N and S. Xl may be further selected from N and NH. X2 may be
further
selected from CR6 and CR7R8. X2 may be further selected from N, NH, and S. X2
may
be further selected from N and NH. Xl and X2 each may be further independently
selected from N and NH.
For the organic heterocyclic compounds of Formula 1, Yl may be SH. Xl may
be selected from N, NH, and S. Xl may be selected from N and S. Xl may be
selected
from N and NH. X3 may be selected from N, NH, 0, and S. X3 may be selected
from N,
NH, and S. X3 may be selected from N and NH. Xl and X3 may be each
independently
selected from N, NH and S. Xl and X3 may be each independently selected from N
and
NH. Xl may be selected from N and NH, and X3 may be selected from CR6 and
CR7R8.
For the organic heterocyclic compounds of Formula 1, Yl may be SH, and Xl
and X2 may each be independently selected from N, NH, and S. Xl may be further
selected from N and S. Xl may be further selected from N and NH. X2 may be
further
selected from CR6 and CR7R8. X2 may be further selected from N, NH, and S. X2
may
be further selected from N and NH. Xl and X2 each may be further independently
selected from N and NH.
For the organic heterocyclic compounds of Formula 1, Yl may be NH2. Xl may
be selected from N, NH, and S. Xl may be selected from N and S. Xl may be
selected
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from N and NH. X3 may be selected from N, NH, 0, and S. X3 may be selected
from N,
NH, and S. X3 may be selected from N and NH. Xl and X3 may be each
independently
selected from N, NH and S. Xl and X3 may be each independently selected from N
and
NH. Xl and X3 may be selected from N and NH, and X2 may be selected from CR6
and
CR7R8.
For the organic heterocyclic compounds of Formula 1, Yl may be NH2, and Xl
and X3 may each be independently selected from N, NH, and S. Xl may be further
selected from N and S. Xl may be further selected from N and NH. X2 may be
further
selected from CR6 and CR7R8. X3 may be further selected from N, NH, and S. X3
may
be further selected from N and NH. Xl and X3 each may be further independently
selected from N and NH, and X2 may be selected from CR6 and CR7R8.
Optionally fused groups of ring A may be monocyclic or polycyclic. Optional
fused groups of the A ring may be optionally substituted mono- or bicyclic
aryl,
heteroaryl or heterocyclic ring, for example where a compound of Formula 1 is
a
bicyclic compound. The monocyclic aryl groups may be an optionally substituted
6
membered ring, such as benzene. The polycyclic aryl groups may be two or more
optionally substituted 6-member rings fused together, such as naphthalene,
anthracene,
pyrene, tetracene, and pentacene. The heteroaryl groups may be selected from 5-
membered monocyclic rings, such as thiophene, furan, pyrrole, silole,
imidazole, 1,3-
thiazole, 1,3,4-oxadiazole, 1,3,4-thiadiazole, or 6 membered rings, such as
pyridine and
triazine, wherein each ring may be optionally substituted.
Optional substituents of ring A ring may be selected from halogen, cyano,
carboxy, amino, hydroxy, alkanoic acid, alkanoate salt, carbamoyl,
Cioalkyloxycarbonyl, Ci-Cioalkyl, Ci-Ciohaloalkyl, Ci-Cioalkylamino, C3-
Ciocycloalkyl, C2-Cioalkenyl, C3-Ciocycloalkenyl, C2-Cioalkynyl, C3-
Ciocycloalkynyl,
aryl and arylCi-Cioalkyl, heteroaryl and heteroarylCi-Cioalkyl, Ci-
Cioalkyloxy, C3-
Ciocycloalkyloxy and wherein amino, alkanoic acid, alkanoic salt,
alkyloxycarbonyl,
alkyl, haloalkyl, alkylamino, cycloalkyl, alkenyl, cycloalkenyl, alkynyl,
cycloalkynyl,
aryl, arylalkyl, heteroaryl, heteroarylalkyl, alkyloxy and cycloalkyloxy in
each
occurrence may be optionally substituted, for example further substituted with
one or
more of halogen, hydroxyl, amino, nitro, carboxylic acid. The optional
substitution may
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be any one or more groups selected from halogen, alkyl, formyl, and amino. The
optional substituents may include salts of the functional groups, for example
carboxylate salts.
Ring A may be heterocyclic, for example an unsaturated heterocyclic
compound. Ring A may be heteroaromatic or partially unsaturated. For example,
ring A
may contain one or more double bonds between ring atoms. Ring A may also
contain
one or more optional substituents and optional fused groups. Ring A may be a
monocyclic 5 or 6 membered heteroaryl or heterocyclic ring. Ring A may be a
bicyclic
ring comprising two rings joined together that are each independently selected
from 5
and 6 membered rings. Ring A may be a bicyclic ring comprising two rings fused
together that are each independently selected from 5 and 6 membered rings.
Ring A
may be a bicyclic heteroaryl or heterocyclic ring containing a 5 membered
heterocyclic
ring fused to a 6 membered aryl, carbocyclic, heterocyclic or heteroaryl ring.
The organic heterocyclic compound may be selected from a compound of
Formula 1(a) or salts thereof:
A27X1
; A
X3 y1
Formula 1(a)
wherein
A, Y1, X1 and X3 are defined according to Formula 1 as described above;
A1, A2 and A3 are each independently selected from C=0, C=S, N, NR13, 0, S,
SO2, CR14, CR15R16;
R13 is selected from hydrogen, amino, CrCioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl,
aryl or
heteroaryl group may be optionally substituted; and
R14, R'5
and R16, are each independently selected from hydrogen, halogen, thiol,
amino, CrCioalkyl, C2-Cioalkenyl, C2-Cioalkynyl, aryl and heteroaryl, in which
each
amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl group may be optionally
substituted,
and optionally two of R13, R14, R15 and R16 ,join together to form an
optionally
substituted aryl or heteroaryl ring fused to the A ring.
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In an embodiment, Aland A3 are CR14. In another embodiment, le is selected
from amino and thiol. In another embodiment, A1 and A3 are each independently
selected from C-SH and C-NH2. In another embodiment, A1 and A3 are C-SH. In
another embodiment, Y1 is SH. In another embodiment, X1 and X2 are N. In
another
embodiment, A2 is N. Some specific examples of compounds of Formula 1(a) are
.. provided as follows:
NH2 0
OH
JL
S*SH H2N N SH HS NSH
The organic heterocyclic compound may be selected from a compound of
Formula 1(a)(i) or salts thereof:
,Y3
X1
A )
y2 x3 yl
Formula 1(a)(i)
wherein
A is a 5- or 6-membered aryl, heteroaryl or heterocyclic ring, which is
optionally substituted with one or more substituents and optionally fused with
one or
more aryl or heteroaryl rings, wherein a dotted line represents one or more
optional
double bonds;
A2, X1 and X3 are each independently selected from N, NH, 0, and S;
Y1, Y2 and Y3 are each independently selected from NH2, S or SH, wherein the
dotted line represents a double bond when Y1 is S or is absent when Y1 is SH
or NH2;
X1 and X2 are defined according to Formula 1 as described above;
A1, A2 and A3 are each independently selected from C=0, C=S, N, NR13, 0, S,
SO2, CR14, CR15R16; and
R14,
R51 and R16 are defined according to Formula la as described above.
In an embodiment, A2, X1 and X2 are N. In another embodiment, Y1, Y2 and Y3
are SH.
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5 Some specific examples of compounds of Formula 1(a)(i) are provided as
follows:
SH SNa NH2
)\
N N N N N N
A
A A
HS N,L sH NaS N SNa H2N N NH2
In one embodiment, the organic heterocyclic compound may be selected from a
compound of Formula 1(b) or salt thereof:
Xi
A ;) _______________________________________
= ----X3
Formula 1(b)
wherein
A ring is an optionally substituted 5-membered heterocyclic ring, wherein a
dotted line represents one or more optional double bonds;
X1, x3 and Y1 are defined according to Formula 1 as described above;
A1 and A2 are each independently selected from C=0, C=S, N, NR13, 0, S, SO2,
CR14 and CR15R16; and are optionally joined together to form an optionally
substituted
aryl, heteroaryl or heterocyclic ring J that is fused to the A ring;
R13 is selected from hydrogen, amino, Cl-Cioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl,
aryl or
heteroaryl group may be optionally substituted; and
R14, ¨15
x and le, are each independently selected from hydrogen, halogen,
carboxyl, amino, Cl-Cioalkyl, C2-Cioalkenyl, C2-Cioalkynyl, aryl and
heteroaryl, in
which each amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl group may be
optionally
substituted, and optionally two of R13, R14, R15 and R16 ,join together to
form an
optionally substituted aryl or heteroaryl ring fused to the A ring.
Some specific examples of compounds of Formula 1(b) are provided as follows:
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= N)
)¨SH
SS
HN-N H2NN,s
¨SH
The at least one organic heterocyclic compound may be selected from a
compound of Formula 1(b)(i) or salt thereof:
,X1
A ; ____________________________________
'x3
Formula 1(b)(i)
wherein
A ring is an optionally substituted 5-membered heterocyclic ring, wherein a
dotted line represents one or more optional double bonds;
X1, X3 and Y1 are defined according to Formula lb as described above;
A1 and A2 are each independently selected from N, NR13, 0, S, CR14 and
CR15R16;
R13 is selected from hydrogen, amino, Cl-Cioalkyl, C2-CioalkalY1, C2-
Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl,
aryl or
heteroaryl group may be optionally substituted; and
R14, 15
R and R16 are defined according to Formula lb as described above..
Some specific examples of compounds of Formula 1(b)(i) are provided as
follows:
NH2 SH NH2
,N ,N N
HS ,
The organic heterocyclic compound may be selected from a compound of
Formula 1(b)(ii) or salt thereof:
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J4
\ _....-X1
>
J3,'---'s,`---;'--ss
1 : J ) : A ) ----yl
J2`..._...."..-/
,j1X3
Formula 1(b)(ii)
wherein
A ring is an optionally substituted 5-membered heterocyclic ring and J ring is
an
optionally substituted 6-membered aryl or heterocyclic ring, wherein a dotted
line
represents one or more optional double bonds;
X1, X3 and Y1 are defined according to Formula la as described above;
J1, J-2, 3 J and J4 are each independently selected from N, NR13, 0, S, CR14
and
CR15R16;
R'3 is selected from hydrogen, amino, Cl-Cioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl,
aryl or
heteroaryl group may be optionally substituted; and
R14,
R51 and le, are each independently selected from hydrogen, halogen,
carboxyl, amino, Cl-Cioalkyl, C2-Cioalkenyl, C2-Cioalkynyl, aryl and
heteroaryl, in
which each amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl group may be
optionally
substituted.
Some specific examples of compounds of Formula 1(b)(ii) are provided as
follows:
N-----N rN-N
)---NH2
N N N N
H H
The organic heterocyclic compound may be selected from a compound of
Formula 1(b)(iii) or salt thereof:
j 4
/ \ _....--X1
J3,'"--'=,',----
1 ( J ) ( A ),x2
J2,.....,,,,,i,....//
'===-=.ji ----x3
Formula 1(b)(iii)
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wherein
A ring is an optionally substituted 5-membered heterocyclic ring and J ring is
an
optionally substituted 6-membered aryl or heterocyclic ring, wherein a dotted
line
represents one or more optional double bonds;
X1, X2, X3 are defined according to Formula la as described above;
Y1 is absent;
J1, J-2, 3 J and J4 are each independently selected from N, NR13, 0, S, CR14
and
CR15R16;
R13 is selected from hydrogen, amino, Cl-Cioalkyl, C2-Cioalkenyl, C2-
Cioalkynyl, aryl and heteroaryl, in which each amino, alkyl, alkenyl, alkynyl,
aryl or
heteroaryl group may be optionally substituted; and
R14,
R51 and R16, are each independently selected from hydrogen, halogen,
carboxyl, amino, Cl-Cioalkyl, C2-Cioalkenyl, C2-Cioalkynyl, aryl and
heteroaryl, in
which each amino, alkyl, alkenyl, alkynyl, aryl or heteroaryl group may be
optionally
substituted.
Some specific examples of compounds of Formula 1(b)(iii) are provided as
follows:
N
NN 110 N,
It will be appreciated that any of the embodiments or examples described above
or herein for Formula 1 may also provide embodiments for any compounds of
Formula
1(a), 1(a)(i), 1(b), 1(b)(i), 1(b)(ii) or 1(b)(iii).
The organic compounds may exist as one or more stereoisomers. The various
stereoisomers can include enantiomers, diastereomers and geometric isomers.
Those
skilled in the art will appreciate that one stereoisomer may be more active
than the
other(s). In addition, the skilled person would know how to separate such
stereoisomers. Accordingly, the present disclosure comprises mixtures,
individual
stereoisomers, and optically active mixtures of the compounds described
herein.
Some specific examples of heteroaryl and heterocyclic organic compounds of
Formula 1 are shown in Table 1 as follows:
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Table 1
Ref. No. Chemical Name Chemical Structure
1 1H-benzotriazole
2 benzimidazole
N
3 1,2,4-triazole
'N
HN N
4 1,2,4-triazole-3-thiol
3-amino,5-merc apto- 1,2,4- H 2N N
5 I I ,¨SH
triazole N-N
HN¨N1
6 3-amino- 1,2,4-triazole
NH2
NH2
1,3,5-triazine-2,4,6-
N N
7
triamine
NH2 N NH2
5-methyl-2-mercapto- NN
8
1,3,4-thiadiazole H
N-N
5-amino-2-merc apto- 1,3,4-
9
thiadiazole
H2N s SH
9H-purine-8-thiol N N
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SNa
1,3,5-triazine-2,4,6-
11 N -N
trithiol, trisodium salt
NaS N SNa
12 2-mercaptopyrimidine,
sodium salt
SNa
5
METAL SALTS, METAL ANIONS AND METAL COMPLEXES
The corrosion inhibitors of the present disclosure may be selected from metal
salts, metal anions, or in the form of a metal complex. The metals of the
metal
salts,metal anions and metal complexes may be selected from alkali earth
metals,
10 transition metals and rare earth metals, for example a group consisting
of Zn, La, Pr,
Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ce, Co, Y, Bi, Cd, Pb, Ag, Sb, Sn,
Cu,
Fe, Ni, Li, Ca, Sr, Mg, Zr, Nd, Ba, Mo, Sc, W, V, and any combinations
thereof. The
combined corrosion inhibitor formulations may comprise at least one metal
salt, at least
one metal anion, or at least one metal complex, wherein the metal is selected
from the
15 group consisting of Zn, La, Pr, Ce, Co, Cu, Y, Ca, Sr, Ba, Gd, Dy, Er,
Tb, Mo, Sc, Sm,
and Zr. The metals may be selected from at least one of Zn, Co, Cu, Mo, Ce,
Gd, Dy,
Er, Lu, Tb, Sm, and Pr. The metals may be selected from at least one of Zn,
Co, Cu,
Mo, Sm, Ce, Er, Lu, and Gd. The metals may be selected from Zn, Mo, Co, Cu W,
V,
Zr, Sm, Dy, Tb, Ce, Pr, Er, Tm, Lu and Gd. The metals may be selected from Zn,
20 Mo, Co, Cu, W, V, Zr, Ce, Pr, Er, Lu, and Gd. The metals may be selected
from Zn,
Mo, Co, Cu, Ce, Gd, Er, Lu, W, and Zr. The metals may be selected from Zn, Co,
Cu,
Mo, Pr, Gd, Er and Lu. The metals may be selected from Zn, Mo, Pr, Ce, Gd, Er
and
Lu. The metals may be selected from at least one of Zn, Mo, and Gd.The metal
may be
Zn. The metal may be Mo. The metal may be Pr. The metal may be Gd. The metal
may
25 be Dy. The metal may be Sm. The metal may be Er. The metal may be Lu.
The metal
may be Co. The metal may be Cu. The metal may be Tb. The metal may be W. The
metal may be V. The metal may be Zr. It will be appreciated that the metals
may have
different oxidation states. For example, the typical oxidation state for Zn is
-2, +1
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and/or +2. The typical oxidation states for Pr are +2, +3, +4 and/or +5. The
typical
oxidation states for Ce are +2, +3 and +4. The typical oxidation states for Mo
are -4, -2,
-1, +1, +2, +3, +4, +5 and/or +6. The typical oxidation states for Gd are +1,
+2, and/or
+3. The typical oxidation states for Tb are +1, +2, +3 and/or +4. The typical
oxidation
states for Dy are +2, +3 and/or +4. The typical oxidation states for Er are +2
and/or +3.
It will be appreciated that various combinations and groups of the above
mentioned
metal salts, metal anions, metal complexes, may be used in the formulations of
the
present disclosure.
It will be appreciated that reference to metal salt in the combined corrosion
inhibiting formulations described herein refers to a metal in the form of a
metal salt
comprising both anions and cations. For example a Cl anion is the counterion
for a Zn
metal cation. Some example counterions that may be used are NO3-, Cl-, 5042-,
Nat
For example, the metal salt may be selected from at least one of ZnC12, CoC12,
CuC12,
CeC13, ErC13, LuC13, PrC13, SmC13, GdC13 and DyC13.
It will be appreciated that reference to metal anion in the combined corrosion
inhibiting formulations described herein refers to a metal in the form of a
metal anion.
For example, the metal anion may be selected from at least one of Mo042-,
V043,
Zr042-, W042-. The metal anion may be Mo042-. The metal anion may be V043-.
The
metal anion may be Zr042-. The metal anion may be W042-. Some example
counterions
that may be used are Na, Zn, NH4t
It will be appreciated that reference to metal complex in the combined
corrosion
inhibitor formulations described herein refers to a metal in the form of a
metal
complex. It will also be appreciated that reference to metal complex in the
combined
corrosion inhibitor formulations described herein may refer to a metal-organic
complex. A metal complex may be formed when a combined corrosion inhibitor
formulation comprises at least two corrosion inhibitors, and may for example
comprise
at least three or a least four corrosion inhibitors. For example, a metal
complex may be
formed from an organic heterocyclic compound of Formula 1 and a metal selected
from
the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm,
Yb, Lu,
Co, Cu, Y, Ca, Sr, B a, Sc, Mo, W, V and Zr. A further example, a metal
complex may
be formed when the corrosion inhibitors are selected from at least one metal
salt and at
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least one organic heterocyclic compounds of Formula 1. A metal complex may be
formed when the corrosion inhibitors are selected from at least one metal
anion and at
least one organic heterocyclic compounds of Formula 1. A metal complex may be
formed when the corrosion inhibitors are selected from at least two metal
salts and at
least two organic heterocyclic compounds of Formula 1. A metal complex may be
formed when the corrosion inhibitors are selected from at least two metal
anions and at
least two organic heterocyclic compounds of Formula 1. The metal complex may
form
from the reaction of each of the at least two metal salts or metal anions with
each of the
at least two organic heterocyclic compounds of Formula 1. The combined
corrosion
inhibitor formulation may comprise at least two metal-organic complexes. A
metal
.. complex may be formed when then the corrosion inhibitors are selected from
at least
one metal salt and at least one metal anion. For example, the metal complex
may be
zinc molybdate, praseodymium molybdate, cerium molybdate, erbium molybdate,
lanthanum molybdate, gadolinium molybdate, lutetium molybdate, dysprosium
molybdate, zinc vanadate, praseodymium vanadate, cerium vanadate, erbium
vanadate,
lanthanum vanadate, gadolinium vanadate, lutetium vanadate, dysprosium
vanadate,
zinc zirconate, praseodymium zirconate, cerium zirconate, erbium zirconate,
lanthanum
zirconate, gadolinium zirconate, lutetium zirconate, dysprosium zirconate,
zinc
tungstate, praseodymium tungstate, cerium tungstate, erbium tungstate,
lanthanum
tungstate, gadolinium tungstate, lutetium tungstate, dysprosium tungstate,
praseodymium benzotriazole, zinc benzotriazole, cerium benzotriazole, erbium
benzotriazole, lanthanum benzotriazole, gadolinium benzotriazole, dysprosium
benzotriazole, lutetium benzotriazole, gadolinium benzotriazole, gadolinium
molybdate, praseodymium benzimidazole, dysprosium benzimidazole, lutetium
benzimidazole, zinc benzimidazole, cerium benzimidazole, erbium benzimidazole,
lanthanum benzimidazole, gadolinium benzimidazole.
SUBSTRATES FOR CORROSION PROTECTION
Substrates that may be protected from corrosion by the corrosion inhibiting
agents or compositions thereof as described herein may be metal substrates. It
will be
appreciated that the metal substrate can include any substrate material having
at least a
portion of its surface being metallic, for example a portion of its external
surface being
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metallic. The metal substrate may comprise any metal requiring protection from
corrosion. The metal substrate may comprise a metal or alloy selected from
steel,
copper, magnesium brass, bronze and zinc. The metal substrate may be steel,
for
example mild steel, carbon steel, stainless steel, high strength/low alloy
steel,
galvanised steel, Al-Zn coated steel, and weathering steel. For example the
metal
substrate may be mild steel.
COMBINATIONS, COMPOSITIONS AND FORMULATIONS
The present disclosure also relates to compositions for inhibiting corrosion
comprising at least a first and second corrosion inhibitor formulation for
inhibiting
corrosion of a substrate wherein the first corrosion inhibitor formulation
comprises at
.. least one corrosion inhibitor and the second corrosion inhibitor
formulation comprises
at least one corrosion inhibitor that is different to the corrosion inhibitor
of the first
corrosion inhibitor formulation. The corrosion inhibitors are each
independently
selected from the group consisting of an organic heterocyclic compound of
Formula 1
as described herein and a metal salt, metal anion, metal complex, or any
combination
thereof, wherein the metal is selected from rare earth, alkali earth and
transition metals,
as described herein, or any embodiments thereof. It will be appreciated that
reference to
any combined corrosion inhibitor formulation in the composition described
herein
refers to the individual corrosion inhibitors themselves together in one
composition and
not reaction products thereof.
For example, the combined corrosion inhibitor formulation may comprise at
least one organic heterocyclic compound of Formula 1 as described herein or
any
embodiments thereof and at least one metal salt, metal anion or metal complex,
wherein
the metal is selected from the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu,
Gd, Tb,
Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, W, V, and Zr. For
example,
the metal may be any one of Zn, Mo, Gd, Dy, Er, Tb, and Pr; the metal may be
Zn, Mo,
and Gd; the metal may be Mo, W, V and Zr; the metal may be Zn, V, and Er; the
metal
may be Zn, V, and Lu; the metal may be Co, V, and Er; the metal may be Zn, W,
and
Er; the metal may be Zn, W, and Lu; the metal may be Co, Mo, and Er; the metal
may
be Co, Mo, Lu; the metal may be Cu, Mo, Er; the metal may be Cu, Mo, and Pr;
the
metal may be Cu, Mo, and Lu; the metal may be Zn, Mo, and Er; the metal may be
Zn,
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Mo and Lu; the metal may be Zn, Mo and Pr; the metal may be Zn, Mo, and Gd;
the
metal may be Gd, Mo, and Er; the metal may be Gd, Mo, Lu; the metal may be Gd,
Mo, Er; the metal may be Gd, Mo, and Pr; the metal may be Gd, Mo, and Lu; or
the
metal may be Zn, Mo, and Gd; the metal may be Zn; the metal may be Mo; the
metal
may be Gd; the metal may be Er; the metal may be Dy; the metal may be W; the
metal
may be V; or the metal may be Zr.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, Co, Cu, Mo, Gd,
Dy, Er,
Tb, Sm, Lu, W, V, and Pr; the metal may be Mo, W, V and Zr; the metal may be
Zn, V,
and Er; the metal may be Zn, V, and Lu; the metal may be Co, V, and Er; the
metal
may be Zn, W, and Er; the metal may be Zn, W, and Lu; the metal may be Co, Mo,
and
Er; the metal may be Co, Mo, Lu; the metal may be Cu, Mo, Er; the metal may be
Cu,
Mo, and Pr; the metal may be Cu, Mo, and Lu; the metal may be Zn, Mo, and Er;
the
metal may be Zn, Mo and Lu; the metal may be Zn, Mo and Pr; the metal may be
Zn,
Mo, and Gd; the metal may be Gd, Mo, and Er; the metal may be Gd, Mo, Lu; the
metal may be Gd, Mo, Er; the metal may be Gd, Mo, and Pr; the metal may be Gd,
Mo,
and Lu; or the metal may be Zn, Mo, and Gd.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, La, Pr, Ce, Nd,
Sm, Eu,
Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, V, W and Zr;
the
metal may be Mo, W, V and Zr; the metal may be Zn, V, and Er; the metal may be
Zn,
V, and Lu; the metal may be Co, V, and Er; the metal may be Zn, W, and Er; the
metal
may be Zn, W, and Lu; the metal may be Co, Mo, and Er; the metal may be Co,
Mo,
Lu; the metal may be Cu, Mo, Er; the metal may be Cu, Mo, and Pr; the metal
may be
Cu, Mo, and Lu; the metal may be Zn, Mo, and Er; the metal may be Zn, Mo and
Lu;
the metal may be Zn, Mo and Pr; the metal may be Zn, Mo, and Gd; the metal may
be
Gd, Mo, and Er; the metal may be Gd, Mo, Lu; the metal may be Gd, Mo, Er; the
metal
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5 may be Gd, Mo, and Pr; the metal may be Gd, Mo, and Lu; or the metal may
be Zn,
Mo, and Gd.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as described
herein
or any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
10 wherein the metal is selected from the group consisting of Zn, Co, Cu,
Mo, Gd, Dy, Er,
Tb, Sm, Lu, W, V, and Pr; the metal may be Mo, W, V and Zr; the metal may be
Zn, V,
and Er; the metal may be Zn, V, and Lu; the metal may be Co, V, and Er; the
metal
may be Zn, W, and Er; the metal may be Zn, W, and Lu; the metal may be Co, Mo,
and
Er; the metal may be Co, Mo, Lu; the metal may be Cu, Mo, Er; the metal may be
Cu,
15 Mo, and Pr; the metal may be Cu, Mo, and Lu; the metal may be Zn, Mo,
and Er; the
metal may be Zn, Mo and Lu; the metal may be Zn, Mo and Pr; the metal may be
Zn,
Mo, and Gd; the metal may be Gd, Mo, and Er; the metal may be Gd, Mo, Lu; the
metal may be Gd, Mo, Er; the metal may be Gd, Mo, and Pr; the metal may be Gd,
Mo,
and Lu; or the metal may be Zn, Mo, and Gd.
20 The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(ii) or salt thereof, as
described herein
or any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, Co, Cu, Mo, Gd,
Dy, Er,
Tb, Sm, Lu, W, V, and Pr; the metal may be Mo, W, V and Zr; the metal may be
Zn, V,
25 and Er; the metal may be Zn, V, and Lu; the metal may be Co, V, and Er;
the metal
may be Zn, W, and Er; the metal may be Zn, W, and Lu; the metal may be Co, Mo,
and
Er; the metal may be Co, Mo, Lu; the metal may be Cu, Mo, Er; the metal may be
Cu,
Mo, and Pr; the metal may be Cu, Mo, and Lu; the metal may be Zn, Mo, and Er;
the
metal may be Zn, Mo and Lu; the metal may be Zn, Mo and Pr; the metal may be
Zn,
30 Mo, and Gd; the metal may be Gd, Mo, and Er; the metal may be Gd, Mo,
Lu; the
metal may be Gd, Mo, Er; the metal may be Gd, Mo, and Pr; the metal may be Gd,
Mo,
and Lu; or the metal may be Zn, Mo, and Gd.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(iii) or salt thereof, as
described herein
35 or any embodiments thereof and at least one metal salt, metal anion, or
metal complex,
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41
wherein the metal is selected from the group consisting of Zn, Co, Cu, Mo, Gd,
Dy, Er,
Tb, Sm, Lu, W, Vand Pr; the metal may be Mo, W, V and Zr; the metal may be Zn,
V,
and Er; the metal may be Zn, V, and Lu; the metal may be Co, V, and Er; the
metal
may be Zn, W, and Er; the metal may be Zn, W, and Lu; the metal may be Co, Mo,
and
Er; the metal may be Co, Mo, Lu; the metal may be Cu, Mo, Er; the metal may be
Cu,
Mo, and Pr; the metal may be Cu, Mo, and Lu; the metal may be Zn, Mo, and Er;
the
metal may be Zn, Mo and Lu; the metal may be Zn, Mo and Pr; the metal may be
Zn,
Mo, and Gd; the metal may be Gd, Mo, and Er; the metal may be Gd, Mo, Lu; the
metal may be Gd, Mo, Er; the metal may be Gd, Mo, and Pr; the metal may be Gd,
Mo,
and Lu; or the metal may be Zn, Mo, and Gd.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, Co, Cu, Gd, Er,
Lu, Mo,
W, V and Zr.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, Co, Cu, Gd, Er,
Lu, Mo,
W, V and Zr.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as described
herein
or any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, Co, Cu, Gd, Er,
Lu, Mo,
W, V and Zr.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(ii) or salt thereof, as
described herein
or any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, Co, Cu, Gd, Er,
Lu, Mo,
W, V and Zr.
The combined corrosion inhibitor formulation may comprise at least one
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42
organic heterocyclic compound of Formula 1(b)(iii) or salt thereof, as
described herein
or any embodiments thereof and at least one metal salt, metal anion, or metal
complex,
wherein the metal is selected from the group consisting of Zn, Co, Cu, Gd, Er,
Lu, Mo,
W, V and Zr.
The combined corrosion inhibitor formulation may comprise at least two
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least two
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least two
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least two
organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as described
herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least two
organic heterocyclic compound of Formula 1(b)(ii) or salt thereof, as
described herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least two
organic heterocyclic compound of Formula 1(b)(iii) or salt thereof, as
described herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least three
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least three
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least three
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
any embodiments thereof.
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The combined corrosion inhibitor formulation may comprise at least three
organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as described
herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least three
organic heterocyclic compound of Formula 1(b)(ii) or salt thereof, as
described herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least three
organic heterocyclic compound of Formula 1(b)(iii) or salt thereof, as
described herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least four
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least four
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least four
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least four
organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as described
herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least four
organic heterocyclic compound of Formula 1(b)(ii) or salt thereof, as
described herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least four
organic heterocyclic compound of Formula 1(b)(iii) or salt thereof, as
described herein
or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(a)(i) or salt thereof, as described herein or any embodiments thereof.
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The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b)(i) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b)(ii) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b)(iii) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(a)(i) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b)(i) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
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5 1(b)(ii) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a)(i) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b)(iii) or salt thereof, as described herein or any embodiments thereof.
10 The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
15 organic heterocyclic compound of Formula 1(b) or salt thereof, as
described herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
1(b)(i) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
20 any embodiments thereof and at least one organic heterocyclic compound
of Formula
1(b)(ii) or salt thereof, as described herein or any embodiments thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b) or salt thereof, as described
herein or
any embodiments thereof and at least one organic heterocyclic compound of
Formula
25 1(b)(iii) or salt thereof, as described herein or any embodiments
thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as described
herein
or any embodiments thereof and at least one organic heterocyclic compound of
Formula 1(b)(i) or salt thereof, as described herein or any embodiments
thereof.
30 The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as described
herein
or any embodiments thereof and at least one organic heterocyclic compound of
Formula 1(b)(ii) or salt thereof, as described herein or any embodiments
thereof.
The combined corrosion inhibitor formulation may comprise at least one
35 organic heterocyclic compound of Formula 1(b)(i) or salt thereof, as
described herein
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.. or any embodiments thereof and at least one organic heterocyclic compound
of
Formula 1(b)(iii) or salt thereof, as described herein or any embodiments
thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(ii) or salt thereof, as
described herein
or any embodiments thereof and at least one organic heterocyclic compound of
Formula 1(b)(ii) or salt thereof, as described herein or any embodiments
thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(ii) or salt thereof, as
described herein
or any embodiments thereof and at least one organic heterocyclic compound of
Formula 1(b)(iii) or salt thereof, as described herein or any embodiments
thereof.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(b)(iii) or salt thereof, as
described herein
or any embodiments thereof and at least one organic heterocyclic compound of
Formula 1(b)(iii) or salt thereof, as described herein or any embodiments
thereof.
The combined corrosion inhibitor formulation may comprise at least two metal
salts, metal anions, metal complexes, or any combination thereof, wherein the
metal is
selected from the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy,
Ho, Er,
Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, W. V, and Zr. For example, the
metal may
be any one of Zn, Mo, Gd, Dy, Er, Tb, and Pr; the metal may be Zn, Co, Cu, Gd,
Er,
Lu, Mo, W, V and Zr; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo and W; the
metal
may be Zn, Co, Cu, Gd, Er, Lu, Mo and V; the metal may be Zn, Co, Cu, Gd, Er,
Lu,
Mo and Zr; the metal may be Zn, Gd, Er, Lu, W and V; the metal may be Zn, Gd,
Er,
Lu, W and Zr; the metal may be Zn, Gd, Er, Lu, V and Zr; the metal may be Zn,
Co,
Cu, Mo, Gd, Er and Lu; the metal may be Zn, Mo, and Gd; the metal may be Zn
and
Mo; the metal may be Mo and Gd; the metal may be Gd and Dy; the metal may be
Mo
and Sm; or the metal may be Dy and Zn.
The combined corrosion inhibitor formulation may comprise at least three metal
salts, metal anions, metal complexes or any combination thereof, wherein the
metal is
selected from the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy,
Ho, Er,
Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, V, W and Zr. For example, the metal
may
be any one of Zn, Mo, Gd, Dy, Er, Tb, and Pr; the metal may be Zn, Co, Cu, Gd,
Er,
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Lu, Mo, W, V and Zr; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo and W; the
metal
may be Zn, Co, Cu, Gd, Er, Lu, Mo and V; the metal may be Zn, Co, Cu, Gd, Er,
Lu,
Mo and Zr; the metal may be Zn, Gd, Er, Lu, W and V; the metal may be Zn, Gd,
Er,
Lu, W and Zr; the metal may be Zn, Gd, Er, Lu, V and Zr; the metal may be Zn,
Co,
Cu, Mo, Gd, Er and Lu; the metal may be Zn, Mo, and Gd; the metal may be Zn,
Dy
and Mo; the metal may be Mo, Dy and Gd; the metal may be Gd, Er, and Zn; or
the
metal may be Dy, Er and Gd.
The combined corrosion inhibitor formulation may comprise at least four metal
salts, metal anions, metal complexes, or any combination thereof, wherein the
metal is
selected from the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy,
Ho, Er,
Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc, Mo, and Zr. For example, the metal may
be any
one of Zn, Mo, Gd, Dy, Er, Tb, and Pr; the metal may be Zn, Co, Cu, Gd, Er,
Lu, Mo,
W, V and Zr; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo and W; the metal may
be
Zn, Co, Cu, Gd, Er, Lu, Mo and V; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo
and
Zr; the metal may be Zn, Gd, Er, Lu, W and V; the metal may be Zn, Gd, Er, Lu,
W
and Zr; the metal may be Zn, Gd, Er, Lu, V and Zr; the metal may be Zn, Co,
Cu, Mo,
Gd, Er and Lu; the metal may be Zn, Mo, Dy and Gd; the metal may be Zn, Dy, Er
and
Mo; the metal may be Mo, Dy, Tb and Gd; the metal may be Gd, Er, Tb, and Zn;
or the
metal may be Tb, Dy, Er and Gd.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1(a) or salt thereof, as described
herein or
any embodiments thereof and at least one metal salt, metal anion, metal
complex, or
any combination thereof, wherein the metal is selected from the group
consisting of Zn,
La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba,
Sc,
Mo, V, W and Zr; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo, W, V and Zr; the
metal may be Zn, Co, Cu, Gd, Er, Lu, Mo and W; the metal may be Zn, Co, Cu,
Gd, Er,
Lu, Mo and V; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo and Zr; the metal
may be
Zn, Gd, Er, Lu, W and V; the metal may be Zn, Gd, Er, Lu, W and Zr; or the
metal may
be Zn, Gd, Er, Lu, V and Zr; or the metal may be Zn, Co, Cu, Mo, Gd, Er and
Lu.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1 or salt thereof, as described
herein or any
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.. embodiments thereof and at least one metal salt, metal anion, metal
complex, or any
combination thereof, wherein the metal is selected from the group consisting
of Zn, La,
Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba, Sc,
Mo, V,
W and Zr. For example the at least one metal salt, metal anion, metal complex,
or any
combination thereof may be Zn, Co, Cu, Mo, Sm, Dy, Tb, Pr, Er, Tm, Lu and Gd;
Zn,
Co, Cu, Mo, Pr, Er and Gd; or Zn, Mo, and Gd; the metal may be Zn, Co, Cu, Gd,
Er,
Lu, Mo, W, V and Zr; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo and W; the
metal
may be Zn, Co, Cu, Gd, Er, Lu, Mo and V; the metal may be Zn, Co, Cu, Gd, Er,
Lu,
Mo and Zr; the metal may be Zn, Gd, Er, Lu, W and V; the metal may be Zn, Gd,
Er,
Lu, W and Zr; or the metal may be Zn, Gd, Er, Lu, V and Zr; or the metal may
be Zn,
Co, Cu, Mo, Gd, Er and Lu.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1 or salt thereof, as described
herein or any
embodiments thereof and at least two metal salts, metal anions, metal
complexes, or
any combination thereof, wherein the metal is selected from the group
consisting of Zn,
La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba,
Sc,
Mo, V, W and Zr. For example the at least two metal salts, metal anions, metal
complexes, or any combination thereof may be Zn, Co, Cu, Mo, Sm, Dy, Tb, Pr,
Er,
Tm, Lu and Gd; or Zn, Mo, Pr, Er and Gd; or Zn, Mo, and Gd; the metal may be
Zn,
Co, Cu, Gd, Er, Lu, Mo, W, V and Zr; the metal may be Zn, Co, Cu, Gd, Er, Lu,
Mo
and W; the metal may be Zn, Co, Cu, Gd, Er, Lu, Mo and V; the metal may be Zn,
Co,
Cu, Gd, Er, Lu, Mo and Zr; the metal may be Zn, Gd, Er, Lu, W and V; the metal
may
be Zn, Gd, Er, Lu, W and Zr; the metal may be Zn, Gd, Er, Lu, V and Zr; or the
metal
may be Zn, Co, Cu, Mo, Gd, Er and Lu.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1 or salt thereof, as described
herein or any
embodiments thereof and at least three metal salts, metal anions, metal
complexes, or
any combination thereof, wherein the metal is selected from the group
consisting of Zn,
La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Co, Cu, Y, Ca, Sr, Ba,
Sc,
Mo, V, W and Zr. For example the at least three metal salts, metal anions,
metal
complexes, or any combination thereof may be Co, Cu, Zn, Mo, Sm, Dy, Tb, Pr,
Er,
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49
Tm, Lu, V, W and Gd; or Co, Cu, Zn, Mo, Pr, Er and Gd; the metal may be Co,
Cu, Zn,
Gd, Er, Lu, Mo, W, V and Zr; the metal may be Co, Cu, Zn, Gd, Er, Lu, Mo and
W; the
metal may be Co, Cu, Zn, Gd, Er, Lu, Mo and V; the metal may be Co, Cu, Zn,
Gd, Er,
Lu, Mo and Zr; the metal may be Co, Cu, Zn, Gd, Er, Lu, W and V; the metal may
be
Co, Cu, Zn, Gd, Er, Lu, W and Zr; the metal may be Co, Cu, Zn, Gd, Er, Lu, V
and Zr;
or Co, Cu Zn, Mo, Er, Lu and Gd.
It will be appreciated that any of the embodiments or examples described above
or herein for Formula 1 may also provide embodiments for any compounds of
Formula
1(a), 1(a)(i), 1(b), 1(b)(i), 1(b)(ii) or 1(b)(iii).
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1 or salt thereof, as described
herein or any
embodiments thereof and at least one metal salt, metal anion, metal complex,
or any
combination thereof, wherein the metal is selected from the group consisting
Zn, Co,
Cu, Mo, Pr, Gd, Er, Lu, W, V and Zr. For example the at least one metal salt,
metal
anion, metal complex, or any combination thereof may be Mo, Co, Cu, W, V, Gd,
Er,
Lu and Zr; the metal may be Zn, Co, Cu, Mo, Gd, Er and Lu; the metal may be
Mo; the
metal may be V; the metal may be Zr; the metal may be Er; the metal may be Lu;
the
metal may be Co; the metal may be Cu; the metal may be Gd; or the metal may be
W.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1 or salt thereof, as described
herein or any
embodiments thereof and at least two metal salts, metal anions, metal
complexes, or
any combination thereof, wherein the metal is selected from the group
consisting of Zn,
Co, Cu, Mo, W, V, Pr, Gd, Er, Lu, and Zr. For example the at least two metal
salts,
metal anions, metal complexes, or any combination thereof may be Mo, W, V, Gd,
Er,
Lu, and Zr; the metal may be Mo, Gd, Er, Lu and W; the metal may be Mo, Gd,
Er, Lu,
.. and V; the metal may be Mo, Gd, Er, Lu, Pr, and Zr; the metal may be W, Gd,
Er, Lu,
Pr, and V; the metal may be W, Gd, Er, Lu, Pr, and Zr; the metal may be V, Gd,
Er, Lu,
Pr, and Zr; or the metal may be Zn, Co, Cu, Mo, Gd, Er and Lu.
The combined corrosion inhibitor formulation may comprise at least one
organic heterocyclic compound of Formula 1 or salt thereof, as described
herein or any
embodiments thereof and at least three metal salts, wherein the metal is
selected from
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5 the group consisting of Zn, Co, Cu, Mo, W, V, Gd, Er, Lu, Pr and Zr. For
example the
at least three metal salts, metal anions, metal complexes, or any combination
thereof
may be Zn, Mo, W, Gd, Er, Lu, Pr, V and Zr; the metal may be Zn, Mo, V, Gd,
Er, Lu,
Pr, and W; the metal may be Zn, Mo, W, Gd, Er, Lu, Pr, and Zr; the metal may
be Zn,
Gd, Er, Lu, V, W, Pr and Zr; or the metal may be Zn, Co, Cu, Mo, Zr, Pr, Lu,
Gd, Er
10 and V; or Zn, Co, Cu, Mo, Gd, Er and Lu.
It will be appreciated that any of the embodiments or examples described above
or herein for Formula 1 may also provide embodiments for any compounds of
Formula
1(a), 1(a)(i), 1(b), 1(b)(i), 1(b)(ii) or 1(b)(iii).
The combined corrosion inhibitor formulation may comprise at least two
15 organic heterocyclic compound of Formula 1 or salt thereof, as described
herein or any
embodiments thereof and at least two metal salts, metal anions, metal
complexes, or
any combination thereof, wherein the metal is selected from the group
consisting of Zn,
La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Co, Y, Ca, Sr, Ba, Sc,
Mo,
W, V and Zr. For example the at least two metal salts, metal anions, metal
complexes,
20 or any combination thereof may be Zn, Co, Cu, Mo, Sm, Dy, Tb, Pr, Er,
Tm, Lu and
Gd; or Zn, Co, Cu, Mo, Pr, Er, Lu, and Gd; or Zn, Mo, Er, Lu and Gd; or Zn,
Co, Cu,
Mo, Gd, Er and Lu.
A further advantage can be provided when the combined corrosion inhibitor
formulations comprise at least three corrosion inhibitors as described herein
or any
25 .. embodiments thereof. For example, the combined corrosion the combined
corrosion
inhibitor formulation may comprise, for example (i) at least two metal salts
and at least
one organic heterocyclic compound of Formula 1 or (ii) at least one metal
salt, at least
one metal anion and at least one organic heterocyclic compound of Formula 1 or
(iii) at
least two metal complexes, or (iv) at least one metal complex and at least one
metal
30 anion.
The combined corrosion inhibitor formulation may be according to (i), and the
at least two metal salts may be selected from the group consisting of Pr3+,
Gd3+, Ce3+,
Dy3+, Sm3+, Er3+, Lu3+, Zn2+, CO2
, CU2+, and the at least one organic heterocyclic
compound of formula 1 may be selected from the group consisting of 3-amino-
1,2,4-
35 .. triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-
thiadiazole, 9H-
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purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-methy1-2-
mercapto-1,3,4-
thiadiazole. The at least two metal salts may be Pr3+, Gd3+, Ce3+, Er3+, Lu3+,
Zn2+, Co2+,
and the at least one organic heterocyclic compound of Formula 1 may be 3-amino-
1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-
thiadiazole.
The combined corrosion inhibitor formulation may be according to (ii), and the
at least one metal salt may be selected from the group consisting of Pr3+,
Gd3+, Ce3+,
Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, the at least one metal anion may be
selected
from the group consisting of Mo042-, V043, Zr042 , W042-, and the at least one
organic
heterocyclic compound of Formula 1 may be selected from the group consisting
of 3-
amino-1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-
1,3,4-
thiadiazole, 9H-purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-
methy1-2-
mercapto-1,3,4-thiadiazole. The at least one metal salt may be Pr3+, Gd3+,
Ce3+, Er3+,
Lu3+, Zn2+, Co2+, the at least one metal anion may be Mo042-, V043-, W042-,
and the at
least one organic heterocyclic compound of Formula 1 may be 3-amino-1,2,4-
triazole,
benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-thiadiazole.
The combined corrosion inhibitor formulation may be according to (iii), and
the
at least two metal complexes may be selected from the group consisting of zinc
molybdate, erbium molybdate, lutetium molybdate, zinc vanadate, zinc
benzotriazole,
dysprosium benzotriazole, lutetium benzotriazole, gadolinium benzotriazole,
gadolinium molybdate, praseodymium benzimidazole, lutetium benzimidazole, zinc
benzimidazole. The at least two metal complexes may be zinc molybdate,
lutetium
molybdate, zinc benzotriazole, lutetium benzotriazole, gadolinium
benzotriazole,
gadolinium molybdate.
The combined corrosion inhibitor formulation may be according to (iv), and the
at least one metal complex may be selected from the group consisting of zinc
molybdate, erbium molybdate, lutetium molybdate, zinc vanadate, zinc
benzotriazole,
dysprosium benzotriazole, lutetium benzotriazole, gadolinium benzotriazole,
gadolinium molybdate, praseodymium benzimidazole, lutetium benzimidazole, zinc
benzimidazole, and the at least one metal anion may be selected from the group
consisting of Mo042-, V043-, Zr042-, W042-. The at least one metal complex may
be
zinc molybdate, lutetium molybdate, zinc benzotriazole, lutetium
benzotriazole,
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gadolinium benzotriazole, gadolinium molybdate, and the at least one metal
anion may
be Mo042-, V043-, Zra42-=
A further advantage can be provided when the combined corrosion inhibitor
formulations comprise at least four corrosion inhibitors as described herein
or any
embodiments thereof. For example, the combined corrosion inhibitor formulation
may
comprise at least four corrosion inhibitors comprising, for example (v) at
least two
metal salts and at least two organic heterocyclic compounds of Formula 1; or
(vi) at
least one metal salt, at least one metal anion, and at least two organic
heterocyclic
compounds of Formula 1; or (vii) at least three corrosion inhibitors selected
from metal
salts, metal anions, metal complexes, or any combinations thereof, and at
least one
organic heterocyclic compound of Formula 1.
The combined corrosion inhibitor formulation may be according to (v), and the
at least two metal salts may be selected from the group consisting of Pr3+,
Gd3+, Ce3+,
Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, and the at least two organic
heterocyclic
compounds of Formula 1 may be selected from the group consisting of 3-amino-
1,2,4-
triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-
thiadiazole, 9H-
purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-3-thiol, and 5-methy1-2-
mercapto-1,3,4-
thiadiazole. The at least two metal salts may be Pr3+, Gd3+, Ce3+, Er3+, Lu3+,
Zn2+, Co2+,
and the at least two organic heterocyclic compounds may be 3-amino-1,2,4-
triazole,
benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-thiadiazole.
The combined corrosion inhibitor formulation may be according to (vi), and the
at least one metal salt may be selected from the group consisting of Pr3+,
Gd3+, Ce3+,
Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, and the at least one metal anion may
be
selected from the group consisting of Mo042-, V043-, Zr042-, W042-, and the at
least
two organic heterocyclic compounds of Formula 1 may be selected from the group
consisting of 3-amino-1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-
2-
mercapto-1,3,4-thiadiazole, 9H-purine-8-thiol, 1,2,4-triazole, 1,2,4-triazole-
3-thiol, and
5-methyl-2-mercapto-1,3,4-thiadiazole. The at least one metal salt may be
Pr3+, Gd3+,
Ce3+, Er3+, Lu3+, Zn2+, Co2+, the at least one metal anion may be Mo042-, V043-
, Zr042-,
and the at least two organic heterocyclic compounds of Formula 1 may be 3-
amino-
1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-1,3,4-
thiadiazole.
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The combined corrosion inhibitor formulation may be according to (vii), and
the
at least three corrosion inhibitors selected from metal salts, metal anions,
metal
complexes, or any combinations thereof, may be selected from the group
consisting of
Pr3+, Gd3+, Ce3+, Dy3+, Sm3+, Er3+, Lu3+, Zn2+, Co2+, Cu2+, Mo042-, V043-,
Zr042-,
W042-, zinc molybdate, lutetium molybdate, zinc benzotriazole, lutetium
benzotriazole,
gadolinium benzotriazole, gadolinium molybdate, and the at least one organic
heterocyclic compound of Formula 1 may be selected from the group consisting
of 3-
amino-1,2,4-triazole, benzimidazole, 1H-benzotriazole, 5-amino-2-mercapto-
1,3,4-
thiadiazole. The at least three corrosion inhibitors selected from metal
salts, metal
anions, metal complexes, or any combinations thereof, may be Pr3+, Gd3+, Ce3+,
Er3+,
Lu3+, Zn2+, M0042-, W042-, lutetium molybdate, zinc benzotriazole, and the at
least one
organic heterocyclic compound of Formula 1 may be 3-amino-1,2,4-triazole,
benzimidazole, 1H-benzotriazole.
It will be appreciated that any of the embodiments or examples described above
or herein for Formula 1 may also provide embodiments for any compounds of
Formula
1(a), 1(a)(i), 1(b), 1(b)(i), 1(b)(ii) or 1(b)(iii).
The corrosion inhibitor compositions are suitable for use and application to
various substrates, such as metal substrates, and for example can be provided
for use in
coolant systems, air-conditioning systems, water and waste water treatment
plants, and
pipelines. The compositions may be used dissolved in a fluid, such as water.
For
example the composition may be dissolved in fluid coolant systems or cooling
towers.
The corrosion inhibitor compositions are suitable for use and application to
various substrates, such as metal substrates, and for example can be provided
as coating
compositions. The compositions may include one or more other additives or
corrosion
inhibiting agents suitable for particular use with a type of substrate.
The corrosion inhibiting compositions may be a film forming formulation. For
example the combined corrosion inhibitor formulations may form a thin film on
a
substrate. The film may be in the form of a layer or coating. The film forming
formulation may form a thin film on a substrate where the inhibitors
chemically adsorb
on the surface of the substrate and form a protective thin film with inhibitor
effect or by
combination between inhibitor ions and substrate surface. A key advantage of a
thin
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54
film on a substrate is that the film may provide a layer or coating over a
substrate that
may effectively prevent corrosion of the substrate. A further advantage of the
thin film
may be that the thin film provides good surface coverage of the substrate. A
further
example of the thin film may be that the inhibitors may be electrochemically
attracted
to the electrochemically active sites of the metal substrate, thereby
preventing corrosion
at either the anodic or cathodic sites, or both the anodic and cathodic sites.
The film may comprise at least one organic heterocyclic compound of Formula
1 as described herein or any embodiments thereof and at least one metal salt,
metal
anion, metal complex, or any combination thereof, wherein the metal is
selected from
the group consisting of Zn, La, Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm,
Yb, Lu,
Co, Cu, Y, Ca, Sr, B a, Sc, Mo, V, W and Zr. For example, the metal may be any
one of
Zn, Co, Cu, Mo, Gd, Dy, Er, Lu, Tb, and Pr; the metal may be Co, Cu, Zn, Mo,
Er, Lu,
and Gd; the metal may be Zn; the metal may be Co; the metal may be Cu; the
metal
may be Mo; the metal may be Gd; the metal may be Er, the metal may be Lu; or
the
metal may be Dy.
It will be appreciated that any of the embodiments or examples described above
or herein for Formula 1 may also provide embodiments for any compounds of
Formula
1(a), 1(a)(i), 1(b), 1(b)(i), 1(b)(ii) or 1(b)(iii).
The present disclosure also relates to determining film thickness of a thin
film
following application of a combined corrosion inhibitor formulation, as
described
herein or any embodiments thereof, on a metal substrate.
The thickness of the thin film may be identified using a focused ion beam
(FIB)
scanning electron microscope (SEM) technique. For example, by aligning the SEM
and
FIB at a reference point the thin film on the metal substrate may be inspected
and a
certain area of interest determined. Software patterns may be used to control
where and
how the ion beam is scanning on the metal substrate and therefore where the
thin film
is being removed. The milled area of the metal substrate may be imaged in real
time by
the electron beam while the milling is in progress.
The thin film may have a thickness of from about 5 nm to about 1500 nm, from
about 10 nm to about 1400 nm, from about 20 nm to about 1300 nm, from about 30
nm,
to about 1200 nm, from about 40 nm to about 1100 nm, from about 50 nm to about
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5 1000 nm, from about 60 nm to about 900 nm, 70 nm to about 800 nm, from
about 80
nm to about 700 nm, from about 90 nm to about 600 nm, from about 100 nm to
about
500 nm, from about 150 nm to about 400 nm, from about 200 nm to about 350 nm.
The
film may have a thickness less than about 1500 nm, less than about 1400 nm,
less than
about 1300 nm, less than about 1200 nm, less than about 1100 nm, less than
about 1000
10 nm, less than about 900 nm, less than about 800 nm, less than about 700
nm, less than
about 600 nm, less than about 500 nm, less than about 400 nm, less than about
350 nm.
The corrosion inhibiting composition can be a coating composition comprising
a film-forming organic polymer. The coating composition may be a paint
composition.
The coating composition may comprise one or more resins, for example epoxy
based
15 resins. The coating composition may be a paint composition, for example
an epoxy
resin based paint composition.
The coating composition may be a powder coating composition, for example a
powder coating composition suitable for use in powder coating of various metal
substrates including steel, copper, zinc, or magnesium as described herein.
For
20 example, the metal substrate may be mild steel.
The coating composition may be a spray composition.
The coating compositions can be applied to a substrate, in either a wet or
"not
fully cured" condition that dries or cures over time, that is, solvent
evaporates. The
coatings can dry or cure either naturally or by accelerated means, for example
an
25 ultraviolet light cured system to form a film or "cured" paint. The
coatings can also be
applied in a semi or fully cured state, such as an adhesive.
The corrosion inhibiting composition can also be an encapsulated corrosion
inhibiting composition. The encapsulated corrosion inhibiting composition may
comprise at least two corrosion inhibitors as described herein, or any
embodiments
30 thereof. For example, the encapsulated corrosion inhibitor compositions
may comprise
at least one polymeric film; at least one metal salt, metal anion, metal
complex, or any
combination thereof, wherein the metal is selected from the group consisting
of Zn, La,
Pr, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Co, Y, Ca, Sr, B a, Sc,
Mo, V, W
and Zr; and at least one organic heterocyclic compound of Formula 1 as
described
35 herein or any embodiments thereof. The polymeric film may include a
predetermined
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56
thickness and permeability to permit controlled diffusion of the particle ions
upon
interaction with water.
The corrosion inhibiting composition may be a corrosion inhibiting kit. The
corrosion inhibiting kit may comprise two or more components and for example
include instructions that the compounds are mixed prior to application onto a
metal
substrate. For example a first component may be at least one organic
heterocyclic
compound of Formula 1 as described herein and at least one metal salt, metal
anion,
metal complex, or any combination thereof, wherein the metal is selected from
rare
earth, alkali earth and transition metals, as described herein, or any
embodiments
thereof; and a second component may be a coating composition, for example a
paint
composition. The paint composition may be an epoxy based paint composition. A
third
component may be an additive, for example a hardener for the resin or any
additive
described herein.
The compositions may include a list of ingredients, and/or components, and can
also include a list of instructions for preparing and mixing together the
ingredients,
and/or components to make a coating composition.
It will be appreciated that the compositions can include one or more
additives,
such as pigments, fillers and extenders. Examples of suitable additives with
which the
corrosion inhibitors described herein can be combined include, for example,
binders,
solvents, pigments (including soluble or non-soluble extenders, fillers,
corrosion-
inhibiting pigments, and the like), solvents, additives (e.g., curing agents,
surfactants,
dyes, amino acids and the like), and so forth. Note that some additives can
also
properly be considered a pigment and vice versa (e.g., matting agents). More
specifically, these "additives" include, but are not limited to, glycine,
arginine,
methionine, and derivatives of amino acids, such as methionine sulfoxide,
methyl
sulfoxide, and iodides/iodates, gelatin and gelatin derivatives, such as
animal and fish
gelatins, linear and cyclic dextrins, including alpha and beta cyclodextrin,
triflic acid,
triflates, acetates, talc, kaolin, organic-based ionic exchange resins, such
as organic-
based cationic and anionic exchange resins, organic-based ionic exchange
resins, such
as organic-based cationic and anionic exchange resins, organic-based ionic
exchange
resins that have been pre-exchanged or reacted with the salts, oxides, and/or
mixed
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57
oxides of rare earth material, and metal sulfates, such as sulfates of rare
earth materials,
magnesium sulfate, calcium sulfate (anhydrous and hydrated forms), strontium
sulfate,
barium sulfate, and the like, and combinations thereof.
It will be appreciated that the compositions may comprise, or consist of any
one
or more of the components or additives described herein.
The compositions may also include other additives such as rheology modifiers,
fillers, tougheners, thermal or UV stabilizers, fire retardants, lubricants,
surface active
agents. The additive(s) are usually present in an amount of less than about
10% based
on the total weight of the activation treatment or the combination of
solvent(s), agent(s)
and additive(s). Examples include:
(a) rheology modifiers such as hydroxypropyl methyl cellulose (e.g. Methocell
311, Dow), modified urea (e.g. Byk 411, 410) and polyhydroxycarboxylic acid
amides
(e.g. Byk 405);
(b) film formers such as esters of dicarboxylic acid (e.g. Lusolvan FBH, BASF)
and glycol ethers (e.g. Dowanol, Dow);
(c) wetting agents such as fluorochemical surfactants (e.g. 3M Fluorad) and
polyether modified poly-dimethyl-siloxane (e.g. Byk 307, 333);
(d) surfactants such as fatty acid derivatives (e.g. Bermadol SPS 2543, Akzo)
and quaternary ammonium salts;
(e) dispersants such as non-ionic surfactants based on primary alcohols (e.g.
Merpol 4481, Dupont) and alkylphenol-formaldehyde-bisulfide condensates (e.g.
Clariants 1494);
(f) anti-foaming agents;
(g) anti-corrosion reagents such as phosphate esters (e.g. ADD APT, Anticor
C6), alkylammonium salt of (2-benzothiazolythio) succinic acid (e.g. Irgacor
153
CIBA) and triazine dithiols;
(h) stabilizers such as benzimidazole derivatives (e.g. Bayer, Preventol BCM,
biocidal film protection);
(i) leveling agents such as fluorocarbon-modified polymers (e.g. EFKA 3777);
(j) pigments or dyes such as fluorescents (Royale Pigment and chemicals);
(k) organic and inorganic dyes such as fluoroscein; and
(1) Lewis acids such as lithium chloride, zinc chloride, strontium chloride,
calcium chloride and aluminium chloride.
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(m) Suitable flame retardants which retard flame propagation, heat release
and/or smoke generation which may be added singularly or optionally include:
= Phosphorus derivatives such as molecules containing phosphate,
polyphosphate, phosphites, phosphazine and phosphine functional groups, for
example, melamine phosphate, dimelamine phosphate, melamine
polyphosphate, ammonia phosphate, ammonia polyphosphate, pentaerythritol
phosphate, melamine phosphite and triphenyl phosphine.
= Nitrogen containing derivatives such as melamine, melamine cyanurate,
melamine phthalate, melamine phthalimide, melam, melem, melon, melam
cyanurate, melem cyanurate, melon cyanurate, hexamethylene tetraamine,
imidazole, adenine, guanine, cytosine and thymine.
= Molecules containing borate functional groups such as ammonia borate
and zinc borate.
= Molecules containing two or more alcohol groups such as
pentaerythritol, polyethylene alcohol, polyglycols and carbohydrates, for
example, glucose, sucrose and starch.
= Molecules which endothermically release non-combustible
decomposition gases, such as, metal hydroxides, for example, magnesium
hydroxide and aluminum hydroxide.
= Expandable graphite.
METHOD OF IDENTIFYING CORROSION INHIBITOR COMBINATIONS
The present disclosure also relates to a method of identifying a combined
corrosion inhibitor formulation comprising at least a first and second
corrosion
inhibitor formulation for inhibiting corrosion. The first corrosion inhibitor
formulation
comprises at least one corrosion inhibitor and the second corrosion inhibitor
formulation comprises at least one corrosion inhibitor that is different to
the corrosion
inhibitor of the first corrosion inhibitor formulation. The corrosion
inhibitors are as
described herein or any embodiments thereof.
The main goal in the method is to identify corrosion rate of a combination of
at
least three corrosion inhibitors each independently selected from the group
comprising
an organic heterocyclic compound of Formula 1 as described herein and a metal
salt,
metal anion, metal complex, or any combination thereof, wherein the metal is
selected
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from rare earth, alkali earth and transition metals, as described herein, or
any
embodiments thereof, using a polarization resistance technique.
The polarization resistance technique provides the following advantages: (1)
it
is rapid, for example it increases the number of experiments per unit time,
(2) it is
relatively simple and low cost, (3) the corrosion rate can be obtained
directly from
readings of the applied polarizing current, (4) non-destructive of the
substrate, and can
monitor corrosion inhibitor performance over time.
The polarisation resistance of a corrosion inhibitor may take place in a
sodium
chloride (NaCl) solution and at room temperature for 168 hours using the
polarisation
resistance electrochemical test. The substrate may be a metal substrate steel,
such as
mild steel. The NaCl solutions may be prepared at a concentration from about
10-1- to
about 10-6 M. The combined corrosion inhibitor formulation may be prepared at
a total
concentration of about 10-3 M.
The polarisation resistance test allows for corrosion analysis of the
corrosion
inhibitors and corrosion inhibitor combinations. The method of identifying
corrosion
rate of the corrosion inhibitor combinations is important for this technique
because of
the need to categorise the polarisation resistance value. For example, when
the
polarisation value for the combination of corrosion inhibitors is greater than
the sum of
the polarisation values for each of the individual corrosion inhibitors, the
combination
is categorised as positive. Whereas, when the polarisation value for the
combination of
corrosion inhibitors is less than or equal to the sum of the polarisation
values for each
of individual corrosion inhibitors, the combination is categorised as
negative.
A polarisation resistance value that is categorised as positive may also
referred
to as a synergistic result. A polarisation resistance value that is
categorised as negative
may also be referred to as an antagonistic result.
The process used to identify a combined corrosion inhibitor formulation is
shown schematically below.
Polarisation Mixture Component Ratio
based ---------------- ' testing substitution variation
Selection
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5 The polarisation based selection may include conducting various
polarisation
resistance tests on each individual corrosion inhibitor solution and analysing
the
response. The response obtained for each corrosion inhibitor solution may
indicate
whether a particular corrosion inhibitor is a film-forming inhibitor or an
instantaneous
inhibitor. Additionally, a corrosion inhibitor identified as a film-forming
inhibitor may
10 be classified as having a delayed inhibitive response. And an
instantaneous inhibitor
may be classified as having an immediate inhibitive response. The polarisation
based
selection may provide a database of each individual corrosion inhibitor being
classified
as having a delayed inhibitive response, an immediate inhibitor response, or
an
undefined inhibitive response.
15 For example, polarisation resistance is typically presented in ohms (a).
The
ohms value may be dependent on the exposed surface area of the metal
substrate. For
example, reducing the surface area of the metal substrate below 7E cm2 may
provide
polarisation resistance values of about 100,000 a. For example, for a 7E cm2
mild steel
substrate a polarisation value of about 500 to about 1,000 a may be classified
as a poor
20 corrosion inhibitor. For example, for a 7E cm2 mild steel substrate a
polarisation value of
about 1,000 to about 5,000 a may be classified as a good corrosion inhibitor.
For
example, for a 7E cm2 mild steel substrate a polarisation value of greater
than about
5,000 a may be classified as an excellent corrosion inhibitor.
It will be appreciated that these polarization resistance values may change
with
25 different metal substrates. It will also be appreciated that the
polarization resistance
value is the sum of all the corrosion events occurring simultaneously on the
metal
substrate.
For example, the polarisation resistance value for an immediate inhibitive
response may be provided in a range of about 200 a to about 10,000 a within a
time
30 period of 1 minute to 90 hours, about 250 a to about 9,000 a within a
time period of 1
minute to 85 hours, about 300 a to about 8,000 a within a time period of 1
minute to
80 hours, about 350 a to about 7,000 a within a time period of 1 minute to 75
hours,
about 400 I to about 6,000 I within a time period of 1 minute to 70 hours,
about 450
a to about 5,000 a within a time period of 1 minute to 65 hours, and about 500
a to
35 about 4,000 a within a time period of 1 minute to 60 hours. For example
the
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polarisation resistance value for a delayed inhibitive response may be
provided in a
range of about 200 II to about 10,000 II within a time period of 1 minute to
480 hours,
about 250 II to about 9,000 II within a time period of 1 minute to 432 hours,
about 300
II to about 8,000 II within a time period of 1 minute to 336 hours, about 350
II to
about 7,000 II within a time period of 1 minute to 240 hours, about 400 II to
about
6,000 II within a time period of 1 minute to 216 hours, about 450 II to about
5,000 II
within a time period of 1 minute to 192 hours, and about 500 II to about 4,000
II
within a time period of 1 minute to 168 hours. For example, the polarisation
resistance
value for an undefined inhibitive response may fall in between any one of the
polarisation resistance values described above.
The mixture or combination testing provides a combined corrosion inhibitor
formulation by combining the first and second corrosion inhibitor formulations
together. For example, the combined corrosion inhibitor formulation may
include
selecting at least two corrosion inhibitors from either classification as
described above.
The combined corrosion inhibitor formulation may include selecting at least
three
.. corrosion inhibitors from either classification as described above. The
combined
corrosion inhibitor formulation may include selecting at least four corrosion
inhibitors
from either classification as described above. The polarisation resistance
value for the
combined corrosion inhibitor formulation may be greater than, less than, or
equal to the
sum of the polarisation value for each of the individual corrosion inhibitors.
For
example, if the polarisation value for the combined corrosion inhibitor
formulation is
greater than the sum of the polarisation values for each of the individual
corrosion
inhibitors, the combined corrosion inhibitor formulation is categorised as
positive. For
example, if the polarisation value for the combined corrosion inhibitor
formulation is
less than or equal to the sum of the polarisation values for each of the
individual
corrosion inhibitors, the combination is categorised as negative.
A combined corrosion inhibitor formulation comprising at least a first and
second corrosion inhibitor formulation, wherein the first corrosion inhibitor
formulation comprises a corrosion inhibitor classified as having a delayed
inhibitive
response and the second corrosion inhibitor formulation comprising a corrosion
inhibitor classified as having an immediate inhibitive response may provide a
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polarisation resistance value that is consistent with an enhanced continuous
inhibitive
response. An enhanced continuous inhibitive response may be a polarisation
resistance
value that is greater than the sum of the polarisation values for each of the
individual
corrosion inhibitors, and categorised as positive. For example, if the
combined
corrosion inhibitor formulation comprised a first corrosion inhibitor
formulation
comprising at least one corrosion inhibitor having a delayed inhibitive
response and the
second corrosion inhibitor formulation comprising at least one corrosion
inhibitor
having an immediate inhibitive response may provide a polarisation resistance
value
that is positive and consistent with an enhanced continuous inhibitive
response.
For example the polarisation resistance value for a combined corrosion
inhibitor
having an enhanced continuous inhibitive response may be provided in a range
of about
200 II to about 17,000 II within a time period of 1 minute to 720 hours, about
250 II to
about 16,000 II within a time period of 1 minute to 672 hours, about 300 II to
about
15,000 II within a time period of 1 minute to 576 hours, about 400 II to about
14,000
II within a time period of 1 minute to 504 hours, about 500 II to about 13,000
II within
a time period of 1 minute to 432 hours, about 600 II to about 12,000 II within
a time
period of 1 minute to 360 hours, about 700 II to about 11,000 II within a time
period of
1 minute to 312 hours, about 800 II to about 10,000 II within a time period of
1 minute
to 264 hours, about 900 II to about 9,000 II within a time period of 1 minute
to 216
hours, and about 1,000 II to about 8,000 II within a time period of 1 minute
to 168
hours.
Component substitution may include substitution with any one or more
corrosion inhibitors from a first combined corrosion inhibitor formulation to
provide a
second combined corrosion inhibitor formulation. If the polarisation value for
the
second combined corrosion inhibitor formulation is greater than the sum of the
polarisation values for the first combined corrosion inhibitor formulation,
the second
combined corrosion inhibitor formulation is categorised as positive. If the
polarisation
value for the second combined corrosion inhibitor formulation is less than or
equal to
the sum of the polarisation values for first combined corrosion inhibitor
formulation,
the second combined corrosion inhibitor formulation is categorised as
negative.
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Ratio variation may include variation of the ratio of individual corrosion
inhibitors in a combined corrosion inhibitor formulation. For example, if the
polarisation value for a 1:1:1:1 combined corrosion inhibitor formulation is
less than or
equal to the sum of the polarisation values for each of the individual
corrosion inhibitor
formulations, the 1:1:1:1 combined corrosion inhibitor formulation may be
varied to
provide a combination having a ratio of, for example, 1:2:1:1.
EXAMPLES
In order that the present disclosure may be more clearly understood,
embodiments of the disclosure are described in further detail below by
reference to the
following non-limiting experimental materials, methodologies, and examples.
General procedure for the polarisation resistance electrochemical tests
The combined corrosion inhibitor formulation comprises at least a first
corrosion inhibitor formulation and a second corrosion inhibitor formulation
wherein
the first corrosion inhibitor formulation comprises at least one corrosion
inhibitor, as
described herein, or any embodiments thereof, and the second corrosion
inhibitor
formulation comprises at least one corrosion inhibitor, as described herein,
or any
embodiments thereof, that is different to that of the first corrosion
inhibitor. The first
corrosion inhibitor formulation was prepared by dissolving at least one
corrosion
inhibitor into a solution of 0.1 M NaCl in deionised water. The second
corrosion
inhibitor formulation was prepared by dissolving at least one corrosion
inhibitor into a
solution of 0.1 M NaCl in deionised water. The combined corrosion inhibitor
formulation was prepared by adding the first corrosion inhibitor formulation
and
second corrosion inhibitor formulation together to provide combined corrosion
inhibitor formulation having a total concentration of about 10-3 M.
The metal substrate (3 cm x 3 cm surface area) was abraded to a shiny surface
using coarse grade 120 grit SiC paper followed by less coarse 180 grit SiC
paper. Metal
substrates, for example mild steel, were rinsed with deionised water and air
dried. A
platinum coated mesh and saturated calomel electrode (SCE) constituted the
counter
and reference electrodes respectively to be coupled with the working electrode
to form
a standard 3-electrode cell. Each corrosion inhibitor formulation was left at
an open
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circuit potential (OCP) period of 5 minutes prior to starting the polarisation
scan.
Linear polarization was measured over a potential range of 10 mV vs. OCP at
a scan
rate of 0.167 mV/s every hour for 168 hours. Values of polarization
resistance, Rp, were
deduced from the slope of fitted current density vs. potential lines. The
tests were
performed in 180 ml solutions open to air for 168 hours. The polarisation
experiments
were performed using a 16 channel Biologic VMP3 (variable multichannel
potentiostat) with the EC-lab software v10.4.
Example 1
Na2Mo04 was prepared and analysed according to the general process described
above. GdC13 was prepared and analysed according to the general process
described
above. A 1:1 combination of Na2Mo04 and GdC13 was prepared and analysed
according to the general process described above. The metal substrate was mild
steel
and prepared as described above. Figure 1 shows that the combination provides
an
unexpected synergistic result over the individual corrosion inhibitors. The
polarisation
resistance value for Na2Mo04 is classified as having an immediate inhibitive
response
and the polarisation resistance value GdC13 is classified as having a delayed
inhibitive
response. The polarisation resistance value for the 1:1 combination of Na2Mo04
and
GdC12 is categorized as positive and classified as having an enhanced
continuous
inhibitive response.
Example 2
Na2Mo04 was prepared and analysed according to the general process described
above. SmC13 was prepared and analysed according to the general process
described
above. A 1:1 combination of Na2Mo04 and SmC13 was prepared and analysed
according to the general process described above. The metal substrate was mild
steel
and prepared as described above. Figure 2 shows that the combination provides
an
unexpected antagonistic result over the individual corrosion inhibitors. The
polarisation
resistance value for Na2Mo04 is classified as having an immediate inhibitive
response
and the polarisation resistance value SmC13 is classified as having an delayed
inhibitive
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Na2Mo04 and
SmC13 is categorized as negative.
Example 3
Na2Mo04 was prepared and analysed according to the general process described
10 .. above. ZnC12 was prepared and analysed according to the general process
described
above. A 1:1 combination of Na2Mo04 and ZnC12 was prepared and analysed
according
to the general process described above. The metal substrate was mild steel and
prepared
as described above. Figure 3 shows that the combination provides an unexpected
antagonistic result over the individual corrosion inhibitors. The polarisation
resistance
15 value for Na2Mo04 is classified as having an immediate inhibitive
response and the
polarisation resistance value ZnC12 is classified as having a delayed
inhibitive response.
The polarisation resistance value for the 1:1 combination of Na2Mo04 and ZnC12
is
categorized as negative.
20 Example 4
ZnC12 was prepared and analysed according to the general process described
above. PrC13 was prepared and analysed according to the general process
described
above. Benzotriazole was prepared and analysed according to the general
process
described above. A 1:1 combination of ZnC12and PrC13 was prepared and analysed
25 .. according to the general process described above. A 1:1:1 combination of
ZnC12 and
PrC13 and benzotriazole was prepared and analysed according to the general
process
described above. The metal substrate was mild steel and prepared as described
above.
Figure 4 shows that the 1:1 combination provides an unexpected synergistic
result over
the individual corrosion inhibitors. Figure 4 also shows that the 1:1:1
combination
30 .. provides an unexpected enhanced synergistic result over the 1:1
combination and over
the individual corrosion inhibitors. The polarisation resistance value for the
1:1:1
combination of ZnC12, PrC13 and benzotriazole is categorized as positive and
classified
as having an enhanced continuous inhibitive response.
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Example 5
A 1:1:1 combination of CoC12, PrC13 and Na2Mo04 was prepared and analysed
according to the general process described above. A 1:1:1 combination of
LuC13, 1H-
benzotriazole and Na2Mo04 was prepared and analysed according to the general
process described above. A 1:1:1 combination of CoC12, PrC13, 1H-benzotriazole
was
prepared and analysed according to the general process described above. A
1:1:1
combination of GdC13, 1H-benzotriazole and Na2Mo04 was prepared and analysed
according to the general process described above. A 1:1:1 combination of
ZnC12, NdC13
and Na2Mo04 was prepared and analysed according to the general process
described
above. A 1:1:1 combination of ZnC12, CeC13 and Na2Mo04 was prepared and
analysed
according to the general process described above. The metal substrate was mild
steel
and prepared as described above. The six combinations prepared and analysed
above
were analysed by component substitution.
Figure 5 shows that the 1:1:1 combination of LuC13, 1H-benzotriazole and
Na2Mo04 provides an unexpected enhanced synergistic result over the 1:1:1
combination of GdC13, 1H-benzotriazole and Na2Mo04 when LuC13 is substituted
for
GdC13.
Figure 5 also shows that the 1:1:1 combination of ZnC12, CeC13 and Na2Mo04
provides an unexpected enhanced synergistic result over the 1:1:1 combination
of
ZnC12, NdC13 and Na2Mo04 when NdC13 is substituted for CeC13. The polarisation
resistance value for the 1:1:1 combination of ZnC12, CeC13 and Na2Mo04 is
categorized
as positive and classified as having an enhanced continuous inhibitive
response.
Example 6
A 1:1:1:1 combination of ZnC12, GdC13, Na2W04 and 1H-benzotriazole was
prepared and analysed according to the general process described above. A
1:1:1:1
combination of ZnC12, GdC13, Na2Mo04 and 1,3,5-triazine-2,4,6-triamine was
prepared
and analysed according to the general process described above. A 1:1:1:1
combination
of ZnC12, PrC13, Na2Mo04 and benzimidazole was prepared and analysed according
to
the general process described above. A 1:1:1:1 combination of ZnC12, LuC13,
Na2W04
and 1H-benzotriazole was prepared and analysed according to the general
process
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.. described above. The metal substrate was mild steel and prepared as
described above.
The four combinations prepared and analysed above were analysed by component
substitution. Figure 6 shows that the substitution of a GdC13 for PrC13 and
1,3,5-
triazine-2,4,6-triamine for benzimidazole giving a 1:1:1:1 combination of
ZnC12, PrC13,
Na2Mo04 and benzimidazole provides a polarisation resistance value that is
categorized as positive and classified as having an enhanced continuous
inhibitive
response.
Figure 6 also shows that the combination of a 1:1:1:1 combination of ZnC12,
LuC13, Na2W04 and 1H-benzotriazole provides an unexpected synergistic result
compared to the combination of ZnC12, GdC13, Na2W04 and 1H-benzotriazole. The
substitution of a GdC13 for LuC13 giving a 1:1:1:1 combination of ZnC12,
LuC13,
Na2W04 and 1H-benzotriazole provides a polarisation resistance value that is
categorized as positive and classified as having an enhanced continuous
inhibitive
response.
