U.S. patent application number 13/042774 was filed with the patent office on 2011-06-30 for colorant treated ion exchange resins, method of making, heat transfer systems and assemblies containing the same, and method of use.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. Invention is credited to Aleksei V. Gershun, Filipe J. Marinho, Peter M. Woyciesjes, Bo Yang.
Application Number | 20110159392 13/042774 |
Document ID | / |
Family ID | 35395904 |
Filed Date | 2011-06-30 |
United States Patent
Application |
20110159392 |
Kind Code |
A1 |
Yang; Bo ; et al. |
June 30, 2011 |
COLORANT TREATED ION EXCHANGE RESINS, METHOD OF MAKING, HEAT
TRANSFER SYSTEMS AND ASSEMBLIES CONTAINING THE SAME, AND METHOD OF
USE
Abstract
Disclosed is a colorant treated ion exchange resin comprising at
least 15% of exchangeable groups comprising at least one of an ion,
a Lewis acid, or a Lewis base resulting from a colorant having a
pK.sub.a or pK.sub.b of greater than 5 in an aqueous solution at
25.degree. C., based on the total number of exchangeable groups.
Also disclosed are heat transfer systems, assemblies, fuel cell
systems and methods of maintaining a conductivity of less than 200
.mu.S/cm in a heat transfer fluid that employ the disclosed
colorant treated ion exchange resins. Finally, a method of making
the disclosed colorant treated ion exchange resins is provided.
Inventors: |
Yang; Bo; (Ridgefield,
CT) ; Woyciesjes; Peter M.; (Woodbury, CT) ;
Marinho; Filipe J.; (Danbury, CT) ; Gershun; Aleksei
V.; (Southbury, CT) |
Assignee: |
HONEYWELL INTERNATIONAL
INC.
Morristown
NJ
|
Family ID: |
35395904 |
Appl. No.: |
13/042774 |
Filed: |
March 8, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12571943 |
Oct 1, 2009 |
7901824 |
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13042774 |
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11222506 |
Sep 8, 2005 |
7611787 |
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12571943 |
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60607969 |
Sep 8, 2004 |
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Current U.S.
Class: |
429/434 ;
165/104.11; 521/28 |
Current CPC
Class: |
Y10T 428/249921
20150401; H01M 8/04029 20130101; Y02E 60/50 20130101; H01M 8/04059
20130101; F01P 2011/068 20130101; H01M 8/04007 20130101; Y02P 70/50
20151101; C09K 5/10 20130101; F28F 19/00 20130101; B01J 47/016
20170101 |
Class at
Publication: |
429/434 ; 521/28;
165/104.11 |
International
Class: |
H01M 8/04 20060101
H01M008/04; C08J 5/00 20060101 C08J005/00; F28D 15/00 20060101
F28D015/00 |
Claims
1. An ion exchange resin comprising at least 15% by total number of
exchangeable groups comprising at least one of an ion, a Lewis
acid, or a Lewis base resulting from a colorant having a pK.sub.a
or pK.sub.b of greater than 5 in an aqueous solution at 25.degree.
C., based on the total number of exchangeable groups.
2. The ion exchange resin of claim 1 wherein the colorant is
substantially free of functional groups that will form an ionic
species due to hydrolysis in an aqueous alcohol solution.
3. The ion exchange resin of claim 2 wherein the colorant is
substantially free of functional groups selected from the group
consisting of carboxylate groups, sulfonate groups, phosphonate
groups, quaternary amines, groups that carry a positive charge, and
groups that carry a negative charge.
4. The ion exchange resin of claim 1 wherein the colorant comprises
at least one of the following chromophores: anthraquinone,
triphenylmethane, diphenylmethane, azo containing compounds, disazo
containing compounds, trisazo containing compounds, diazo
containing compounds, xanthene, acridine, indene, phthalocyanine,
azaannulene, nitroso, nitro, diarylmethane, triarylmethane,
methine, indamine, azine, oxazine, thiazine, quinoline, indigoid,
indophenol, lactone, aminoketone, hydroxyketone, stilbene,
thiazole, one or more conjugated aromatic groups, one or more
conjugated heterocyclic groups, one or more conjugated C--C double
bond, or combinations thereof.
5. The ion exchange resin of claim 1 wherein the colorant comprises
the reaction product of a chromophore and a non-conductive alkoxy
radical comprising from 1 to 30 carbons.
6. The ion exchange resin of claim 5 wherein the colorant at least
one chromophore selected from the group consisting of
anthraquinone, triphenylmethane, diphenylmethane, azo containing
compounds, disazo containing compounds, trisazo containing
compounds, diazo containing compounds, or combinations thereof.
7. A heat transfer system, comprising a circulation loop defining a
flow path for a colored heat transfer fluid having a conductivity
of less than 10 .mu.S/cm, and an ion exchange resin positioned in
the flow path, the ion exchange resin comprising at least 15% by
total number of the exchangeable groups comprising a colorant,
based on the total number of the exchangeable groups.
8. The heat transfer system of claim 7, wherein the colored heat
transfer fluid comprises a non-conductive colorant and has a
conductivity of no more than or equal to 10 .mu.S/cm.
9. The heat transfer system of claim 8, wherein the colored heat
transfer fluid has a conductivity of less than 5 .mu.S/cm.
10. The heat transfer system of claim 9, wherein the colored heat
transfer fluid has a conductivity from 0.02 to 5 .mu.S/cm.
11. The heat transfer system of claim 10, wherein the colored heat
transfer fluid has a conductivity from 0.05 to 1 .mu.S/cm.
12. The heat transfer system of claim 8, wherein the non-conductive
colorant is present in an amount of from 0.0001 to 0.2% by weight,
based on the total weight of the colored heat transfer fluid.
13. The heat transfer system of claim 12, wherein the
non-conductive colorant is present in an amount of from 0.0005 to
0.1% by weight, based on the total weight of the colored heat
transfer fluid.
14. The heat transfer system of claim 13 wherein the non-conductive
colorant is present in an amount of from 0.0005 to 0.05% by weight,
based on the total weight of the colored heat transfer fluid.
15. The heat transfer system of claim 7 wherein the colored heat
transfer fluid further comprises an alcohol.
16. The heat transfer system of claim 15 wherein the alcohol is at
least one of methanol, ethanol, propanol, butanol, furfurol,
ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol,
butylene glycol, glycrol, monoethylether of glycerol, dimethyl
ether of glycerol, 1,2,6-hexanetriol, trimethylolpropane,
methoxyethanol, or a combination thereof.
17. The heat transfer system of claim 8 wherein the colorant in the
ion exchange resin and the non-conductive colorant in the colored
heat transfer fluid are the same.
18. The heat transfer system of claim 17 wherein the colorant is
substantially free of functional groups that will form an ionic
species due to hydrolysis in an aqueous alcohol solution.
19. The heat transfer system of claim 18 wherein the colorant is
substantially free of functional groups selected from the group
consisting of carboxylate groups, sulfonate groups, phosphonate
groups, quaternary amines, groups that carry a positive charge, or
groups that carry a negative charge.
20. The heat transfer system of claim 17 wherein the colorant
comprises at least one of the following chromophores:
anthraquinone, triphenylmethane, diphenylmethane, azo containing
compounds, disazo containing compounds, trisazo containing
compounds, diazo containing compounds, xanthene, acridine, indene,
phthalocyanine, azaannulene, nitroso, nitro, diarylmethane,
triarylmethane, methine, indamine, azine, oxazine, thiazine,
quinoline, indigoid, indophenol, lactone, aminoketone,
hydroxyketone, stilbene, thiazole, one or more conjugated aromatic
groups, one or more conjugated heterocyclic groups, one or more
conjugated C--C double bond, or combinations thereof.
21. The heat transfer system of claim 20 wherein the colorant
comprises the reaction product of a chromophore and a
non-conductive alkoxy compound comprising from 1 to 30 carbons.
22. The heat transfer system of claim 21 wherein the colorant
comprises the reaction product of at least one chromophore selected
from the group consisting of anthraquinone, triphenylmethane,
diphenylmethane, azo containing compounds, disazo containing
compounds, trisazo containing compounds, diazo containing
compounds, or combinations thereof.
23. A fuel cell system, comprising at least one fuel cell
comprising an anode, a cathode, and an electrolyte; and a fuel cell
heat transfer system in thermal communication with the at least one
fuel cell, comprising a circulation loop defining a flow path for a
colored liquid heat transfer fluid having a conductivity of less
than 10 .mu.S/cm, and an ion exchange resin positioned in the flow
path, the ion exchange resin comprising ion exchangeable groups,
wherein at least 15% of the total ion exchangeable groups comprise
a colorant.
24. A method of maintaining a conductivity of less than 10 .mu.S/cm
in a colored heat transfer fluid, comprising first contacting an
ion exchange resin with an aqueous colorant solution for a period
of time sufficient to exchange at least 15% of the exchange sites
with at least one of an ion, a Lewis acid, or a Lewis base
resulting from a colorant having a pK.sub.a or pK.sub.b of greater
than 5 in an aqueous solution at 25.degree. C. and forming a
colorant treated ion exchange resin; and later passing a colored
heat transfer fluid through a heat transfer system, wherein the
colored heat transfer fluid has a conductivity of less than 10
.mu.S/cm and the heat transfer system comprises a circulation loop
defining a flow path for the colored heat transfer fluid and the
colorant treated ion exchange resin positioned in the flow
path.
25. The method of claim 24 wherein the colored heat transfer fluid
has a color that is visible to the human eye.
26. A method of making a colorant treated ion exchange resin,
comprising contacting an ion exchange resin with an aqueous
colorant solution for a period of time sufficient to exchange at
least 15% of the exchange sites with at least one of an ion, a
Lewis acid, or a Lewis base resulting from a colorant having a
pK.sub.a or pK.sub.b of greater than 5 in an aqueous solution at
25.degree. C.
27. An assembly powered by an alternative power source comprising
an alternative power source and a heat transfer system in thermal
communication with the alternative power source, the heat transfer
system comprising a circulation loop defining a flow path for a
heat transfer fluid having a conductivity of less than 200
.mu.S/cm, and an ion exchange resin positioned in the flow path,
the ion exchange resin comprising ion exchangeable groups, wherein
at least 15% of the total ion exchangeable groups comprise at least
one of an ion, a Lewis acid, or a Lewis base resulting from a
colorant having a pK.sub.a or pK.sub.b of greater than 5 in an
aqueous solution at 25.degree. C., based on the total number of
exchangeable groups.
Description
[0001] This application is a continuation application of U.S. Ser.
No. 12/571,943, filed Oct. 1, 2009, which is a divisional
application of U.S. Ser. No. 11/222,506, filed Sep. 8, 2005, which
also claims the benefit of U.S. Provisional Application Ser. No.
60/607,969, filed on Sep. 8, 2004, the contents each of which are
incorporated herein by reference thereto.
FIELD OF THE INVENTION
[0002] The invention relates to colorant pre-treated ion exchange
resins and their use in heat transfer systems, alternative power
sources such as fuel cells, and assemblies comprising such power
sources.
BACKGROUND OF THE INVENTION
[0003] Heat transfer systems in thermal communication with a power
source have been utilized to regulate heat generated during the
operation of the power source. For example, automotive vehicles
have employed heat transfer fluids and heat transfer systems that
transfer and dissipate heat generated as a by-product of gasoline
powered internal combustion engines. In this case, the heat
transfer fluids and heat transfer systems ensure that the engine
operates in an optimum environment and is not subject to
undesirably high temperatures.
[0004] However, alternatives to traditional gasoline powered
internal combustion engine are now desired, especially alternatives
that address public concerns regarding the environmental and the
management of natural resources. As a result, new power source
technologies continue to be developed, especially those that
provide improvements in energy efficiency. Examples of alternative
power sources that have been developed include, but are not limited
to, batteries, fuel cells, solar (photovoltaic) cells, and internal
combustion engines powered by the condensation of steam, natural
gas, diesel, hydrogen, and/or the like. Such alternative power
sources may be used alone or in combinations thereof, such as those
employed in hybrid vehicles.
[0005] Although such alternative power sources often provide
improvements in energy efficiency as compared to gasoline powered
internal combustion engines, they continue to require the use of
heat transfer systems and heat transfer fluids. In particular, heat
transfer systems and fluids are necessary to maintain optimum
operating conditions, particularly in regards to temperature.
[0006] Unfortunately, however, traditional prior art heat transfer
systems and heat transfer fluids are unsuitable (or not optimized)
for use with alternative power sources, especially those employing
electricity or an electrical charge. For example, traditional prior
art heat transfer fluids are typically characterized by extremely
high conductivities, often in the range of 3000 .mu.S/cm or more.
The use of highly conductive heat transfer fluids with alternative
power sources, especially electricity based alternative power
sources, can result in electrical shock, increased corrosion and/or
the short-circuiting of electrical current.
[0007] As a result, conventional heat transfer fluids are
unsuitable for use with some alternative power sources; especially
electricity based alternative power sources.
[0008] Fuel cells are a particularly attractive alternative power
source because of their clean and efficient operation. Fuel cells
have been proposed for use in numerous applications.
[0009] For example, it has been proposed that fuel cells replace
the internal combustion engines currently used in automobiles.
Several different kinds of fuel cells are currently under
development and appear to hold promise for use in automotive
applications. Illustrative examples include Proton Exchange
Membrane or Polymer Electrolyte Membrane (PEM) fuel cells,
phosphoric acid (PA) fuel cells, molten carbonate (MC) fuel cells,
solid oxide (SO) fuel cells, and alkaline fuel cells.
[0010] A fuel cell assembly typically comprises an anode, a
cathode, and an electrolyte in between the two electrodes.
Normally, an oxidation reaction (e.g., H.sub.2.fwdarw.2H.sup.++2e)
takes place at the anode and a reduction reaction (e.g.,
O.sub.2+2H.sub.2O+4e.fwdarw.40H.sup.-) takes place at the cathode.
The electrochemical reactions that occur at the electrodes are
exothermic, i.e., they produce heat.
[0011] The successful replacement of internal combustion engines
with fuel cells requires that optimal operating conditions be
achieved and maintained, i.e., a fuel cell must achieve the
desirable current density level without degradation of fuel cell
components. It is therefore necessary to control the exothermic
heat produced during the electrochemical reactions.
[0012] For example, to achieve optimal operating conditions, the
normal operating temperature of a PEM fuel cell assembly is
controlled so that it remains within a range of from 60.degree. C.
to 95.degree. C. Because of the exothermic nature of the
electrochemical reactions, it is desirable to use a heat transfer
fluid or heat transfer fluid to keep the electrode assembly at an
operating temperature that is within the desired operating
temperature range. However, the presence of an electrical charge
makes it challenging to use fuel cells with prior art heat transfer
systems and fluids.
[0013] Moreover, in order to produce sufficient power, a fuel cell
based automotive engine might have many fuel cells connected
together in series to form a fuel cell stack. Individual fuel cells
may have an operating voltage of from 0.6 to 1.0V DC. In one
instance, it is contemplated that anywhere from 100 to 600
individual fuel cells might be connected in series. As a result,
the DC electrical voltage across automotive fuel cell stacks could
be very high, typically ranging from 125 to 450 V DC.
[0014] These same voltages are experienced in the heat transfer
fluid systems of the individual fuel cells used in automotive fuel
cell stacks. To prevent or minimize electrical shock hazard, the
heat transfer fluid must have very low conductivity. Low electrical
conductivity for fuel cell heat transfer fluid is also desirable
for the reduction of shunt current in the heat transfer fluid
system and the minimization of system efficiency reduction.
[0015] There is therefore a need to provide `low conductivity` heat
transfer fluids intended for use in heat transfer systems that are
in thermal communication with alternative power sources.
[0016] In addition to low electrical conductivity, heat transfer
fluids used with alternative power sources must also have high heat
capacity, low viscosity, and high thermal conductivity. Such
properties help minimize pressure drops and reduce pumping power
requirements while still meeting heat transfer requirements. Good
surface wetting properties are also desirable in a heat transfer
fluid employed with alternative power sources. A heat transfer
fluid with good surface wetting characteristics is helpful in
reducing pressure drops at a condition of constant flow rate.
[0017] Another important characteristic of a desirable heat
transfer fluid is corrosion resistance. Many heat transfer fluid
systems used with alternative power sources often have several
metallic components. Illustrative metals found in heat transfer
systems employed with alternative power sources include ferrous and
non ferrous alloys such as stainless steel, aluminum, brass, braze
alloy, and the like. However, such metals are vulnerable to
corrosion as a result of contact with the heat transfer fluid.
[0018] There is therefore a need to provide corrosion inhibiting
heat transfer fluids in heat transfer systems used with alternative
power sources that minimize corrosion and prolong the service life
of the heat transfer system. More particularly, there remains a
need for low conductivity heat transfer fluids that inhibit the
corrosion of heat transfer systems in thermal communication with
alternative power sources.
[0019] Various methods for maintaining low electrical conductivity
in a heat transfer fluid have been proposed. For example, WO
00/17951 proposes the use of an ion exchange resin unit to maintain
adequate purity of a pure glycol and water heat transfer fluid
mixture in a fuel cell system. CA 2 435 593 discloses a method for
deionizing a heat transfer medium of a fuel cell utilizing a two
heat transfer circuit arrangement and a deionization cell wherein a
diluate flows in one heat transfer circuit flowing through a fuel
cell stack and a concentrate flow can be part of a secondary heat
transfer circuit.
[0020] Fuel cell heat transfer fluids must also have high heat
capacity, low viscosity, and high thermal conductivity. Such
properties help minimize pressure drops and reduce pumping power
requirements while still meeting heat transfer requirements. Good
surface wetting properties are also desirable in a fuel cell heat
transfer fluid. A heat transfer fluid with good surface wetting
characteristics is helpful in reducing pressure drops at a
condition of constant flow rate.
[0021] Another important characteristic of a desirable heat
transfer fluid is corrosion resistance. Heat transfer systems often
have several metallic components. Illustrative metals found in fuel
cell heat transfer systems and other heat transfer systems include
ferrous and non ferrous alloys such as stainless steel, aluminum,
brass, braze alloy, and the like. However, such metals are
vulnerable to corrosion as a result of contact with the heat
transfer fluid.
[0022] There is therefore a need provide corrosion inhibiting heat
transfer fluids that minimize corrosion of metallic heat transfer
system components and prolong the service life of fuel cell heat
transfer systems and other heat transfer systems.
[0023] However, many of the corrosion inhibitors previously known
for use in internal combustion engine heat transfer fluids are
unsuitable for use in fuel cell heat transfer fluids because they
are typically highly conductive ionic species. Illustrative
examples of such corrosion inhibitors are silicates, nitrites,
molybdates, nitrates, carboxylates, phosphates, borates, and the
like. Such ionic corrosion inhibitors cannot be used in fuel cell
heat transfer fluids because of the requirement that fuel cell heat
transfer fluids have very low conductivity. One major drawback of
ion exchange resins or electrodeionization cell methods is that
they may remove corrosion inhibitors. As a result, the fuel cell
heat transfer fluid may lose its ability to inhibit the corrosion
of metal components of the fuel cell heat transfer system.
[0024] As a result, the prior art has failed to provide an
effective resolution to problems associated with the maintenance of
low conductivity in corrosion inhibiting heat transfer fluids for
assemblies comprising alternative power sources such as fuel
cells.
[0025] In addition, heat transfer fluids used in traditional
automotive internal combustion engines are almost always colored by
the addition of a dye to provide identity and prevent confusion
with other functional fluids used in automobiles. Such coloring is
also intended to provide information as to the concentration of the
heat transfer fluid and to allow the heat transfer fluid to be
recognizable during and after use in the heat transfer system.
[0026] However, dyes and colorants used in heat transfer fluids
intended for use in internal combustion engines are typically
highly conductive ionic species. Illustrative examples of such dyes
and colorants are Direct Blue 199 (copper phthalocyanine,
tetrasulfonic acid), Acid Green 25
(1,4-bis(4'-methyl-3'phenylsulfonato)amino anthraquinone), Acid Red
52 (sulforhodamine B) and uranine (sodium fluorescein). Such dyes
cannot be used in fuel cell heat transfer fluids because of the
requirement that fuel cell heat transfer fluids have very low
conductivity.
[0027] Thus, the use of dyes can be problematic with respect to
prior art methods for maintaining low electrical conductivity in
heat transfer fluids. One major drawback of ion exchange resins or
electrodeionization cell methods is that they may remove colorants,
even very weakly ionically charged colorants and non-conductive
colorants. As a result, the colored heat transfer fluid may appear
to loose `color` and the benefits obtained with the use of
colorants.
[0028] As a result, the prior art has failed to provide an
effective resolution to problems associated with the maintenance of
low conductivity in colored heat transfer fluids.
SUMMARY OF THE INVENTION
[0029] Disclosed are a colorant treated ion exchange resin, a heat
transfer system, an assembly comprising an alternative power source
such as fuel cell, a fuel cell system, and a method of maintaining
low conductivity in a colored heat transfer fluid.
[0030] In one embodiment, the colorant treated ion exchange resin
comprises at least 15% of exchangeable groups comprising a
colorant, based on the total number of exchangeable groups.
[0031] The disclosed heat transfer system in one embodiment
comprises a circulation loop defining a flow path for a colored
heat transfer fluid having a conductivity of less than 200
.mu.S/cm, and a colorant treated ion exchange resin positioned in
the flow path, wherein the colorant treated ion exchange resin
comprises at least 15% of exchangeable groups comprising a
colorant, based on the total number of exchangeable groups.
[0032] The disclosed assembly is powered by an alternative power
source and comprises an alternative power source and a heat
transfer system in thermal communication with the alternative power
source, the heat transfer system comprising a circulation loop
defining a flow path for a colored heat transfer fluid having a
conductivity of less than 200 .mu.S/cm, and an ion exchange resin
positioned in the flow path, the ion exchange resin comprising ion
exchangeable groups, wherein at least 15% of the total ion
exchangeable groups comprise at least one of an ion, or a Lewis
acid, or a Lewis base resulting from a colorant having a pK.sub.a
or pK.sub.b of greater than 5 in an aqueous solution at 25.degree.
C., based on the total number of exchangeable groups. In one
exemplary embodiment, the alternative power source is a fuel
cell.
[0033] The fuel cell system in one embodiment comprises at least
one fuel cell comprising an anode, a cathode, and an electrolyte;
and a fuel cell heat transfer system in thermal communication with
the at least one fuel cell, wherein the fuel cell heat transfer
system comprises a circulation loop defining a flow path for a
colored liquid heat transfer fluid having a conductivity of less
than 200 .mu.S/cm, and an ion exchange resin positioned in the flow
path, the ion exchange resin comprising at least 15% of ion
exchangeable groups comprising a colorant, based on the total
number of exchangeable groups.
[0034] The disclosed method of maintaining a conductivity of less
than 200 .mu.S/cm in a colored heat transfer fluid comprises
passing a colored heat transfer fluid through a heat transfer
system, wherein the colored fuel cell heat transfer fluid has a
conductivity of less than 200 .mu.S/cm and the heat transfer system
comprises a circulation loop defining a flow path for the colored
heat transfer fluid, and an ion exchange resin positioned in the
flow path, the ion exchange resin comprising at least 15% of
exchangeable groups comprising a colorant, based on the total
number of exchangeable groups.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] FIG. 1 is a schematic diagram of one embodiment of the
disclosed heat transfer system and fuel cell system.
[0036] FIG. 2 is a graph illustrating experimental results and
measuring conductivity versus time.
[0037] FIG. 3 is a schematic diagram of an illustrative assembly
comprising an alternative power source and a heat transfer system,
more particularly a hybrid vehicle cooling system.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0038] Disclosed is a colorant treated ion exchange resin, a heat
transfer system, a fuel cell system, and a method of maintaining
low conductivity in a colored heat transfer fluid.
[0039] The colorant treated ion exchange resin results from the
pretreatment of ion exchange resins with one or more treatment
colorants. In one embodiment, the disclosed colorant treated ion
exchange resins may be made by contacting an ion exchange resin
with an aqueous treatment solution containing one or more treatment
colorants. The treatment results in the exchange of treatment
colorant with at least some of the exchangeable groups in the ion
exchangeable resin.
[0040] Illustrative examples of suitable ion exchange resins
include anion exchange resins, cation exchange resins, mixed bed
ion exchange resins, and mixtures thereof. The particular ion
exchange resin selected is dependent upon the type of heat transfer
fluid colorant used in the colored fuel cell heat transfer
fluid.
[0041] The ion exchange resins suitable for use in the instant
invention will generally have a polymer matrix and functional
groups `paired` with an exchangeable ion form.
[0042] The exchangeable ion form is generally one or more of
Na.sup.+, II.sup.+, OH.sup.-, or Cl.sup.- ions, depending on the
type of ion exchangeable resin. These exchangeable ions exchange
with the ionic species produced by the one or more colorants
present in an aqueous colorant treatment solution. These
exchangeable ions exchange with any ionic species produced by the
one or more colorants present in an aqueous colorant treatment
solution and in some cases with the ionic colorant species present
in a colored heat transfer fluid, especially a colored fuel cell
heat transfer fluid.
[0043] For example, if the colorants become negatively charged
species in solution, i.e., for example if N-heterocyclic compounds
are used as the colorants, the ion exchange resin should be a mixed
bed resin, an anion exchange resin, or a mixture thereof.
Commercially available anion exchange resins are typically in
either OH.sup.- or Cl.sup.- forms. In one exemplary embodiment, a
selected anion exchange resin will be in the OH.sup.- form.
[0044] Alternatively, if the colorants in the colored heat transfer
fluid become positively charged species in solution, then mixed bed
resins, cation exchange resins or a mixture thereof should be used.
Commercially available cation exchange resins are typically in
either H.sup.+ or Na.sup.+ forms. In one exemplary embodiment, a
selected cation exchange resin will be in the H.sup.+ form.
[0045] In one embodiment, ion exchange resins in Na.sup.+ or
Cl.sup.- forms will be used only if the treatment with the aqueous
colorant solution results in the removal of substantially all of
the Na.sup.+ or Cl.sup.- ions from the ion exchange resin. For
example, in one exemplary embodiment, ion exchange resins in
Na.sup.+ or Cl.sup.- forms will be used only if the treatment with
the aqueous colorant solution results in the production of a
colorant treated ion exchange resin having at least 80% of
exchangeable groups comprising a colorant.
[0046] Examples of illustrative polymer matrices include
polystyrene, polystyrene and styrene copolymers, polyacrylate,
aromatic substituted vinyl copolymers, polymethacrylate,
phenol-formaldehyde, polyalkylamine, combinations thereof, and the
like. In one embodiment, the polymer matrix will be polystyrene and
styrene copolymers, polyacrylate, or polymethacrylate, while in one
exemplary embodiment; the polymer matrix will be
styrenedivinylbenzene copolymers.
[0047] Examples of illustrative functional groups in cation ion
exchange resins include sulfonic acid groups (--SO.sub.3H),
phosphonic acid groups (--PO.sub.3H), phosphinic acid groups
(--PO.sub.2H), carboxylic acid groups (--COOH or
--C(CH.sub.3)--COOH), combinations thereof, and the like. In one
embodiment, the functional groups in a cation exchange resin will
be --SO.sub.3H, --PO.sub.3H, or --COOH, while in one exemplary
embodiment; the functional groups in a cation exchange resin will
be `3SO.sub.3H.
[0048] Examples of illustrative functional groups in anion exchange
resins include quaternary ammonium groups, e.g.,
benzyltrimethylammonium groups (also termed type 1 resins),
benzyldimethylethanolammonium groups (also termed type 2 resins),
trialkylbenzyl ammonium groups (also termed type 1 resins); or
tertiary amine functional groups, and the like. In one embodiment,
the functional groups in an anion exchange resin will be
trialkylbenzyl ammonium, trimethylbenzyl ammonium, or
dimethyl-2-hydroxyethylbenzyl ammonium, while in one exemplary
embodiment the functional groups in an anion exchange resin will be
trialkylbenzyl ammonium.
[0049] Commercially available ion exchange resins suitable for use
herein are available from Rohm & Haas of Philadelphia, Pa. as
Amberlite.TM., Amberjee.TM., Duolite.TM., and Imac.TM. resins, from
Bayer of Leverkusen, Germany as Lewatit.TM. resin, from Dow
Chemical of Midland, Mich. as Dowex.TM. resin, from Mitsubishi
Chemical of Tokyo, Japan as Diaion.TM. and Relite.TM. resins, from
Purolite of Bala Cynwyd, Pa. as Purolite.TM. resin, from Sybron of
Birmingham, N.J. as Ionac.TM. resin, from Resintech of West Berlin,
N.J., and the like. In one embodiment, a suitable commercially
available ion exchange resin will be Dowex.TM. MR-3 LC NG Mix mixed
bed resin, Dowex.TM. MR-450 UPW mixed bed resin, Sybron Ionac.TM.
NM-60 mixed bed resin, or Amberlite.TM. MB-150 mixed bed resin,
while in one exemplary embodiment, a suitable commercially
available ion exchange resin will be Dowex.TM. MR-3 LC NG Mix.
[0050] The colorant treated ion exchange resin is contacted with an
aqueous treatment solution comprising a colorant. Such a colorant
may be referred to as a `treatment colorant`. Suitable treatment
colorants for use in the aqueous treatment solution of colorant
include weakly ionic colorants that are soluble or dispersible in
an alcohol or in a mixture of one or more alcohols and water.
[0051] Colorants suitable for use as treatment colorants in one
embodiment will have a pK.sub.a value of equal to or greater than 5
if it is an acid in aqueous solution at 25.degree. C. In one
exemplary embodiment, suitable treatment colorants will have a
pK.sub.a value of from 5 to 14. In one especially exemplary
embodiment, the suitable acid treatment colorants will have a
pK.sub.a value of from 5 to less than 14.
[0052] If a treatment colorant is a base, the pK.sub.b value of
suitable treatment colorants should be equal to or greater than 5
in aqueous solution at 25.degree. C. In one exemplary embodiment,
the suitable basic treatment colorants will have a pK.sub.b value
of from 5 to 14. In one especially exemplary embodiment, the
suitable basic treatment colorants will have a pK.sub.b value of
from 5 to less than 14.
[0053] In one exemplary embodiment, suitable treatment colorants
will possess good stability in a mixture of alcohol and water under
fuel cell operating conditions, i.e., typically temperatures of
from about 40.degree. C. to about 100.degree. C.
[0054] In one embodiment, the treatment colorant will comprise at
least some minimum number of functional groups that will form an
ionic species due to hydrolysis in an aqueous alcohol or alkylene
glycol solution. In embodiment, the treatment colorant may comprise
from 1 to 10 number of ionic forming functional group per molecule,
more preferably from 1 to 5 per molecule of treatment colorant.
Illustrative ionic forming functional groups are those selected
from the group consisting of amine groups, heterocyclic aromatic
groups, and other N-containing groups, and phenol or naphthol
derivatives.
[0055] In one embodiment, the treatment colorant will comprise at
least one of the following chromophores: anthraquinone,
triphenylmethane, diphenylmethane, azo containing compounds, disazo
containing compounds, trisazo containing compounds, diazo
containing compounds, xanthene, acridine, indene, phthalocyanine,
azaannulene, nitroso, nitro, diarylmethane, triarylmethane,
methine, indamine, azine, oxazine, thiazine, quinoline, indigoid,
indophenol, lactone, aminoketone, hydroxyketone, stilbene,
thiazole, one or more conjugated aromatic groups, one or more
conjugated heterocyclic groups, one or more conjugated
carbon-carbon double bonds (e.g., carotene), and combinations
thereof. In one exemplary embodiment, the treatment colorant will
comprise at least one of anthraquinone, acridine, thiazole, azo
containing compounds, triarylmethane, diarylmethane, or
combinations thereof. In one especially exemplary embodiment, the
treatment colorant will comprise an azo containing compound as a
chromophore.
[0056] In another embodiment, the treatment colorants will contain
alkyleneoxy or alkoxy groups and at least one chromophore such as
described above.
[0057] In one embodiment, the chromophore contained in the
colorants will be selected from the group consisting of
anthraquinone, triphenylmethane, diphenylmethane, azo containing
compounds, disazo containing compounds, trisazo containing
compounds, diazo containing compounds, and combinations
thereof.
[0058] Alternatively, suitable treatment colorants may be described
as those colorants of the formula:
R{A.sub.k.left brkt-bot.(B).sub.nR.sup.1.right
brkt-bot..sub.m}.sub.x
wherein R is an organic chromophore that is chemically stable,
soluble at the use concentration and has a desirable toxicity
profile; A is a linking moiety in said chromophore and is selected
from the group consisting of O, N and S; k is 0 or 1; B is selected
from the group consisting of one or more alkyleneoxy or alkoxy
groups containing from 1 to 8 carbon atoms; n is an integer of from
1 to 100; m is 1 or 2; x is an integer of from 1 to 5; and R.sup.1
is selected from the group consisting of H, C.sub.1-C.sub.6 alkyl
or alkoxy groups containing from 1 to 8 carbon atoms, or
combinations thereof.
[0059] In one exemplary embodiment, suitable treatment colorants
are those colorants of the above formula wherein R is selected from
the group consisting of anthraquinone, triphenylmethane,
diphenylmethane, azo containing compounds, disazo containing
compounds, trisazo containing compounds, diazo containing
compounds, xanthene, acridine, indene, phthalocyanine, azaannulene,
nitroso, nitro, diarylmethane, triarylmethane, methine, indamine,
azine, oxazine, thiazine, quinoline, indigoid, indophenol, lactone,
aminoketone, hydroxyketone, stilbene, thiazole, one or more
conjugated aromatic groups, one or more conjugated heterocyclic
groups, or combinations thereof; B is selected from the group of
one or more alkyleneoxy constitutuents containing from 2 to 4
carbon atoms, n is from 1 to 30, m is 1 or 2, X is preferably 1 or
2, and R.sup.1 is preferably H or a C.sub.1-C.sub.4 alkyl or alkoxy
groups containing from 1 to 6 carbon atoms.
[0060] The treatment colorants may be prepared by various known
methods such as are described in U.S. Pat. No. 4,284,729, U.S. Pat.
No. 6,528,564 B1, U.S. Pat. No. 6,635,350 B2 or other patents
issued to Milliken & Company, Spartanburg, S.C., USA. For
example, suitable treatment and/or heat transfer fluid colorants
may be prepared by converting a dyestuff intermediate containing a
primary amino group into the corresponding polymeric compound and
employing the resulting compound to produce a compound having a
chromophoric group in the molecule. In the case of azo dyestuffs,
this may be accomplished by reacting a primary aromatic amine with
an appropriate amount of an alkylene oxide or mixtures of alkylene
oxides, such as ethylene oxide and the like, according to known
procedures, and then coupling the resulting compound with a
diazonium salt of an aromatic amine. Colorants containing ionic
species can be used if purification methods are used to remove the
ionic species to provide the purified colorants with the necessary
pK.sub.a or pK.sub.b values discussed above. Illustrative
purification and chemical separation techniques include, treatment
with ion exchange resins, reversed osmosis, extraction, absorption,
distillation, filtration, etc. and similar processes used to remove
the ionic species and obtained a purified colorant having a
suitable pK.sub.a or pK.sub.b. In order to prepare liquid colorants
of the triarylmethane class, aromatic amines that have been reacted
as stated above with an alkylene oxide are condensed with aromatic
aldehydes and the resulting condensation products oxidized to form
the triarylmethane liquid colorants. Other suitable colorants may
also be prepared by these and other known procedures.
[0061] Commercially available examples of suitable treatment
colorants for use in the disclosed treated ion exchange resins and
methods of making and using include Liquitint.RTM. Red ST or other
similar polymeric colorants from Milliken Chemical of Spartanburg,
S.C., USA, or from Chromatech of Canton, Mich., USA. Other
illustrative colorants include the following: Liquitint.RTM.Red ST,
Liquitint.RTM.Blue RE, Liquitint.RTM.Red XC, Liquitint.RTM.Patent
Blue, Liquitint.RTM.Bright yellow, Liquitint.RTM.Bright orange,
Liquitint.RTM.Royal Blue, Liquitint.RTM.Blue N-6,
Liquitint.RTM.Bright Blue, Liquitint.RTM.Supra Blue,
Liquitint.RTM.Blue HP, Liquitint.RTM.Blue DB, Liquitint.RTM.Blue
II, Liquitint.RTM.Exp. Yellow 8614-6, Liquitint.RTM.Yellow BL,
Liquitint.RTM.Yellow II, Liquitint.RTM.Sunbeam Yellow,
Liquitint.RTM.Supra yellow, Liquitint.RTM.Green HMC,
Liquitint.RTM.violet, Liquitint.RTM.Red BL, Liquitint.RTM.Red RL,
Liquitint.RTM.Cherry Red, Liquitint.RTM.Red II, Liquitint.RTM.Teal,
Liquitint.RTM.Yellow LP, Liquitint.RTM.Violet LS,
Liquitint.RTM.Crimson, Liquitint.RTM.Aquamarine,
Liquitint.RTM.Green HMC, Liquitint.RTM.Red HN, Liquitint.RTM.Red
ST, as well as combinations thereof.
[0062] In one exemplary embodiment, the treatment colorant will be
at least one of Liquitint.RTM. Red ST from Milliken, Liquitint.RTM.
Red XC from Chromatech, Chromatint.RTM. Yellow 1382 from Chromatech
or Liquitint.RTM. Blue RE from Chromatech, while in an especially
exemplary embodiment, the treatment colorant will be Liquitint.RTM.
Red ST from Milliken or Liquitint.RTM. Red XC from Chromatech.
[0063] The aqueous colorant solution used to make the colorant
treated ion exchange resins will generally have a concentration of
treatment colorant as described above of at least 1000 ppm or at a
temperature of greater than 2 degrees C. In one embodiment, the
aqueous colorant solution will have a concentration of from 0.001%
to 90% by weight, while in another embodiment; the aqueous colorant
solution will have a concentration of from 0.005% to 10% by
weight.
[0064] It will be appreciated that in one embodiment, the aqueous
colorant solution will be made with deionized water.
[0065] In one embodiment, the ion exchange resin is contacted with
the aqueous colorant solution for a period of time sufficient to
allow the treatment colorant to exchange places with at least 15%
of the total exchangeable groups, based on the total number of
exchangeable ions in the ion exchange resin. That is, the colorant
loading of the colorant treated ion exchange resin should be at
least 15% of the exchange capacity of the ion exchange resin. In
another embodiment, the period of contact is sufficient to allow
the treatment colorant to exchange places with at least 50% of the
total exchangeable groups, based on the total number of
exchangeable ions in the ion exchange resin. In one exemplary
embodiment, the period of contact is sufficient to allow the
treatment colorant to exchange places with at least 75% of the
total exchangeable groups, based on the total number of
exchangeable ions in the ion exchange resin. In another exemplary
embodiment, the period of contact is sufficient to allow the
colorant loading to be an amount of from 15 to 99% of the total
exchange capacity of the resin or from 15 to 99% of the total
exchangeable groups, based on the total number of exchangeable ions
in the ion exchange resin.
[0066] In one exemplary embodiment, the resultant colorant treated
ion exchange resins will be cleansed with de-ionized water and/or
clean fuel cell heat transfer fluid to minimize the chance for
accidental introduction of impurities.
[0067] In one embodiment, the disclosed colorant treated ion
exchange resin will be used in a fuel cell heat transfer system. In
one exemplary embodiment illustrated in FIG. 1, a suitable fuel
cell heat transfer system 10 will comprise a circulation loop 12
that defines a flow path 14 that is in thermal communication with
at least one fuel cell 16 comprising an anode 18, a cathode 20, and
an electrolyte 22. The term `thermal communication` as used herein
refers to any arrangement that allows heat produced by the
exothermic reaction in the fuel cell 16 to be transferred to the
colored heat transfer fluid by heat transfer. For example, in one
embodiment as illustrated FIG. 1, the flow path 14 will pass
through a heat transfer fluid channel 26 in the fuel cell 16. A
colorant treated ion exchange resin 28 is placed in flow path 14 so
that colored heat transfer fluid 24 must pass there through. In one
embodiment, colorant treated ion exchange resin 28 may be placed in
a filter 30 that is placed in the flow path 14 of circulation loop
12.
[0068] It will be appreciated that numerous configurations for
circulation loop 12 are within the scope of the instant
disclosures. For example, the heat transfer fluid channel 26 may be
comprised of multiple channels or may be configured to wrap around
the fuel cell 16. In general, the heat transfer fluid channels
should be in close proximity to the electrode assembly surfaces
where oxidation reaction of the fuel(s) and/or the reduction
reaction of the oxidant(s) are taking place, so that effective heat
transfer between heat transfer fluid and the electrode assembly can
be accomplished. In addition, the heat transfer fluid channels and
the fuel and oxidant flow channels are generally mechanically
isolated from each other, so that undesirable interference among
fuel, oxidant and heat transfer fluid will not occur.
[0069] In addition to fuel cell heat transfer systems, it will be
appreciated that the disclosed treated ion exchange resins are
suitable for use in applications having heat transfer systems that
require heat transfer fluids having low conductivity. Examples
include glass and metal manufacturing processes. Such processes
often apply a high electrical voltage/current to electrodes used to
keep the glass and/or metal in a molten state. Thus, it will be
appreciated that the disclosed heat transfer systems may also be
used in such applications.
[0070] It will be appreciated that the disclosed heat transfer
fluids may be used in a variety of assemblies comprising one or
more alternative power sources. The term `alternative power source`
as used here refers to power source technologies that provide
improvements in energy efficiency, environmental concerns, waste
production and management issues, natural resource management, and
the like. Examples of alternative power sources that have been
developed include, but are not limited to, batteries, fuel cells,
solar cells or solar panels, photovoltaic cells, and internal
combustion engines powered by the condensation of steam, natural
gas, diesel, hydrogen, and/or the like. In one embodiment, the term
`alternative power source` includes devices powered by internal
combustion engines operating with a clean heat transfer system,
i.e., a heat transfer system that does not contribute to the
concentration of ionic species in the heat transfer fluid. Such
alternative power sources may be used alone or in combinations
thereof, such as those employed in hybrid vehicles.
[0071] It will be appreciated that assemblies comprising such
alternative power sources include any article traditionally powered
by an internal combustion engine, such as automotive vehicles,
boats, generators, lights, aircrafts and airplanes, trains or
locomotives, military transport vehicles, stationary engines, and
the like. The assemblies also include additional systems or devices
required for the proper utilization of alternative power sources,
such as electric motors, DC/DC converters, DC/AC inverters,
electric generators, and other power electronic devices, and the
like. The assemblies may also include systems or devices required
for the proper utilization of the alternative power sources such as
electric motors, DC/CC converters, DC/AC inverters, electric
generators, and other power electronics and electrical devices, and
the like.
[0072] The disclosed assemblies will generally comprise an
alternative power source and a heat transfer system in thermal
communication with the alternative power source. In one embodiment,
the heat transfer system will comprise a circulation loop defining
a flow path for a corrosion inhibiting liquid heat transfer fluid
having a conductivity of less than 200 .mu.S/cm. In one exemplary
embodiment, the heat transfer system will comprise a circulation
loop defining a flow path for a corrosion inhibiting liquid heat
transfer fluid having a conductivity of less than 200 .mu.S/cm and
comprising a corrosion inhibitor comprising an azole compound, and
at least one of a siloxane based surfactant, colloidal silica, or
mixtures thereof.
[0073] As illustrative example of the disclosed assembly may be
seen in FIG. 3. The major components of the cooling system, and the
main system components 16 that may require the use of coolant or
heat transfer fluid as cooling media are shown in the figure. As
indicated therein, the assembly may contain internal combustion
engine 5, or fuel cells 5 or solar cells 5 as the vehicle primary
power source 7. It also contains a rechargeable secondary battery
12 or an optional ultra-capacitor 13 that may be charged via the
vehicle regenerative braking system. In this embodiment, the
battery 12 and/or the ultra-capacitor 13 may act as secondary power
sources. The assembly may also contain power electronic devices,
such as DC/DC conveters 10, DC/AC inverters 10, generators 8, power
splitting devices 9, and/or voltage boost conveters 11, etc. In
addition, the assembly may also contain fuel cell or solar cell
"balance of plant" subsystems 6. These may be air compressors,
pumps, power regulators, etc. The assembly also contain HAVC
systems 14, e.g., air-conditioning system for the climate control
of vehicle interior space. These are included in the vehicle system
16 in the illustrated assembly of FIG. 1 that may require the use
of coolant or heat transfer fluid for temperature control. Similar
to other vehicle cooling systems, the assembly in the illustrate
example also contain a coolant recirculation pump 1, coolant flow
path 4, coolant tank 2, and a radiator or heat exchanger 3, and a
fan 15. The fan may be substituted by an external cooling source,
e.g., a different (or isolated) cooling system with its own cooling
media.
[0074] In one embodiment, the alternative power source will be a
fuel cell. It will be appreciated that a fuel cell is in thermal
communication with the disclosed heat transfer systems and fluids,
the electrical conductivity of the disclosed heat transfer fluids
will be, in one embodiment, no more than 10 .mu.S/cm. In an
especially exemplary embodiment comprising a fuel cell, the
disclosed heat transfer fluids will have an electrical conductivity
of from 0.02 to no more than 10 .mu.S/cm. In one especially
exemplary embodiment, the disclosed corrosion inhibiting heat
transfer fluids will have an electrical conductivity of from 0.05
to no more than 5 .mu.S/cm.
[0075] The disclosed treated ion exchange resins may be used with a
number of different types of fuel cells comprising an electrode
assembly comprising an anode, a cathode, and an electrolyte, and a
heat transfer fluid in thermal communication with the electrode
assembly or fuel cell. In one embodiment the disclosed treated ion
exchange resins may be contained in a flow path defined by a
circulation loop or heat transfer fluid flow channel in thermal
communication with said fuel cell.
[0076] Illustrative types of suitable fuel cells include PEM
(Proton Exchange Membrane or Polymer Electrolyte Membrane) fuel
cells, AFC (alkaline fuel cell), PAFC (phosphoric acid fuel cell),
MCFC (molten carbonate fuel cell), SOFC (solid oxide fuel cell),
and the like. In one exemplary embodiment, the disclosed corrosion
inhibiting heat transfer fluids will be used in PEM and AFC fuel
cells.
[0077] In one embodiment, the disclosed heat transfer systems,
assemblies, and fuel cell systems will also employ suitable colored
heat transfer fluids that may be characterized as having very low
conductivity.
[0078] The term `heat transfer fluid` as used herein refers to a
liquid that is capable of transfers and dissipating a quantity of
thermal energy from a first point to second point. In one
embodiment, the disclosed heat transfer fluids may be referred to
as coolants. In another embodiment, the disclosed heat transfer
fluids may also be referred to as antifreeze, due to the ability of
some heat transfer fluids to function as freezing point
depressants.
[0079] The term low conductivity' as used herein generally refers
to electrical conductivities of no more than 200 .mu.S/cm. In one
embodiment, the disclosed colored heat transfer fluids will have a
conductivity of less than 150 .mu.S/cm, while in another
embodiment, the disclosed colored heat transfer fluids will have a
conductivity of less than 50 .mu.S/cm.
[0080] In other embodiments, the disclosed colored heat transfer
fluids will have an electrical conductivity of from 0.02 .mu.S/cm
to no more than 200 .mu.S/cm. In one embodiment, the disclosed
colored heat transfer fluids for use in fuel cells will have a
conductivity of from 0.2 .mu.S/cm to 100 .mu.S/cm. In another
embodiment, the disclosed colored heat transfer fluids will have a
conductivity of from 0.05 to less than 50 .mu.S/cm, while in one
exemplary embodiment, the disclosed colored heat transfer fluids
will have a conductivity of from 0.05 to no more than 25 .mu.S/cm.
In an especially exemplary embodiment, the disclosed colored heat
transfer fluids will have an electrical conductivity of from 0.05
to no more than 10 .mu.S/cm. In one especially exemplary
embodiment, the disclosed colored heat transfer fluids will have an
electrical conductivity of from 0.05 to no more than 5
.mu.S/cm.
[0081] The electrical conductivity of the disclosed colored heat
transfer fluids may be measured by using the test methods described
in ASTM D1125, i.e., "Standard Test Methods for Electrical
Conductivity and Resistivity of Water" or an equivalent method.
[0082] The disclosed colored heat transfer fluids may also be
corrosion inhibiting. The term `corrosion inhibiting heat transfer
fluid` refers to a heat transfer fluid having a sufficient amount
of one or more corrosion inhibitors such that metallic components
immersed in said fluid have a reduced rate of corrosion relative to
their corrosion in a heat transfer fluid that is identical in all
respects except that it lacks any corrosion inhibitors.
[0083] A `colored heat transfer fluid` as used herein refers to a
heat transfer fluid having a sufficient amount of one or more
colorants such that the color of the heat transfer fluid may be
measured by either the naked eye or by analytical techniques using
selective absorption or scattering of visible light, i.e., light
with wavelengths of approximately between 350 nm and 750 nm
[0084] In one embodiment, the disclosed colored heat transfer
fluids will comprise a non-conductive colorant. In another
embodiment, the disclosed colored heat transfer fluids will
comprise at least one alcohol in addition to the non-conductive
colorant. In one exemplary embodiment, the disclosed colored heat
transfer fluids will comprise a non-conductive colorant, at least
one alcohol, and water. In another exemplary embodiment, the
disclosed colored heat transfer fluids will comprise a
nonconductive colorant, water, at least one alcohol, a corrosion
inhibitor, and optionally one or more of an antifoam agent, a
bittering agent, a wetting agent, a non-ionic dispersant,
combinations thereof, and the like.
[0085] `Heat transfer fluid` as used herein refers to both
concentrated solutions of the corrosion inhibitor and alcohol or
water/alcohol mixtures as well as to diluted solutions of the same
mixed with water, preferably deionized water. It will be
appreciated that although heat transfer fluid may be purchased,
transported or used in concentrated solutions consisting mainly of
one or more alcohols and corrosion inhibitor, such concentrates
will often be diluted with water, especially deionized water, prior
to incorporation or use in a fuel cell. Dilution ratios of from 1:4
to 4:1 (DI water: Heat transfer fluid) are typical, with ratios of
from 40%:60% to 60%:40% being used in one exemplary embodiment.
Thus, the term `heat transfer fluid` as used herein refers to both
concentrated solutions and dilute solutions of the disclosed heat
transfer fluids.
[0086] In one embodiment, suitable heat transfer fluids will
comprise a heat transfer fluid colorant as described herein. In
another embodiment, suitable heat transfer fluids will also
comprise a heat transfer fluid inhibitor as described herein. In
another embodiment, suitable heat transfer fluids will comprise at
least one alcohol in addition to the colorant and corrosion
inhibitor. In one exemplary embodiment, suitable heat transfer
fluids will comprise a corrosion inhibitor, at least one alcohol,
and water. In another exemplary embodiment, a heat transfer fluids
will comprise a corrosion inhibitor as disclosed herein, water, at
least one alcohol, a colorant, and optionally one or more additives
such as an antifoam agent, a bittering agent, a wetting agent, a
non-ionic dispersant and the like.
[0087] As discussed above, in one exemplary embodiment, the heat
transfer fluid used in the disclosed heat transfer systems and fuel
cell systems will be a colored heat transfer fluid that comprises
at least one colorant. The colorant used in the colored heat
transfer fluid, i.e., a `heat transfer fluid colorant` may be the
same or different with respect to the `treatment colorant` used in
the aqueous treatment solution and described above.
[0088] However, it will be appreciated that truly non-conductive
species that do not produce an ionic species in a heat transfer
fluid may also be used as the heat transfer fluid colorant in
addition to those colorant suitable for use as treatment heat
transfer fluids. In contrast with the term `non-conductive` as it
relates to a treatment colorant, the term `non-conductive` with
respect to a heat transfer fluid colorant refers to a colorant that
produces a conductivity of less than about 0.5 .mu.S/cm when
introduced into a standard solution of deionized water with a
conductivity of less than 0.3 .mu.S/cm , at a maximum concentration
of no more than 0.2% by weight, based on the total weight of the
standard solution. In one embodiment, a `non-conductive` colorant
will be a non-ionic species in its pure form. In one exemplary
embodiment, suitable acidic heat transfer fluid colorants will have
a pK.sub.a value of equal to or greater than 5 at 25.degree. C.
while suitable basic heat transfer fluid colorants will have a
pK.sub.b value equal to or greater than 5 at 25.degree. C. in
aqueous solution. In one particularly exemplary embodiment,
suitable acidic heat transfer fluid colorants will have a pK.sub.a
value of greater than 5 and less than 14 at 25.degree. C. while
suitable basic heat transfer fluid colorants will have a pK.sub.b
value greater than 5 and less than 14 at 25.degree. C. in aqueous
solution.
[0089] In one embodiment, at least one treatment colorant present
in a colorant treated ion exchange resin will be the same as at
least one heat transfer fluid colorant used in a colored fuel cell
heat transfer fluid. In another embodiment, at least one treatment
colorant present in a colorant treated ion exchange resin will be
the same as at least one heat transfer fluid colorant used in a
colored fuel cell heat transfer fluid that is used in a fuel cell
heat transfer system employing said colorant treated ion exchange
resin. In one exemplary embodiment, the treatment colorants present
in a colorant treated ion exchange resin will be the same as the
heat transfer fluid colorants used in a fuel cell heat transfer
fluid used in a fuel cell heat transfer system employing said
colorant treated ion exchange resin.
[0090] In one embodiment, a heat transfer fluid colorant will be a
non-conductive colorant that is substantially free of functional
groups that will form an ionic species due to hydrolysis in an
aqueous alcohol or alkylene glycol solution. "Substantially free"
as used herein refers to an amount that is not in excess of an
amount that will lead to the conductivity of the colored heat
transfer fluid being higher than 5 .mu.S/cm. Examples of the
functional groups will produce small amount of ionic species
include many N-containing compounds, e.g., acridine, amine,
thiazole, cresol, etc. Compounds containing sulfonic acid groups,
phosphonic acid groups, carboxylic acid groups, etc. will also
produce ionic species upon hydrolysis in aqueous solution. Since
these groups have a smaller pK.sub.a value, the solution is more
ionic or conductive than the previous group (i.e., the N-containing
compounds). In one specific embodiment, a non-conductive heat
transfer fluid colorant will substantially free of functional
groups selected from the group consisting of carboxylate groups,
sulfonate groups, phosphonate groups, quaternary ammonium groups,
groups that carry a positive charge, and groups that carry a
negative charge. Illustrative examples of groups that carry a
positive charge include Na.sup.+, Cu.sup.2+,
N.sup.+(CH.sub.3).sub.3, Fe.sup.3+, combinations thereof, and the
like. Illustrative examples of groups that carry a negative charge
include Cl.sup.-, Br.sup.-, SO.sub.4.sup.2-, combinations thereof,
and the like. However, in other embodiments, suitable heat transfer
fluid colorants will not be nonconductive as that term is defined
above with respect to heat transfer fluid colorants, and will
comprise such functional groups.
[0091] Notwithstanding the foregoing specific embodiments, the heat
transfer fluid colorant may generally be described as indicated
above with respect to treatment colorants. That is, suitable heat
transfer fluid colorants may comprise at least one of the following
chromophores: anthraquinone, triphenylmethane, diphenylmethane, azo
containing compounds, disazo containing compounds, trisazo
containing compounds, diazo containing compounds, xanthene,
acridine, indene, phthalocyanine, azaannulene, nitroso, nitro,
diarylmethane, triarylmethane, methine, indamine, azine, oxazine,
thiazine, quinoline, indigoid, indophenol, lactone, aminoketone,
hydroxyketone, stilbene, thiazole, one or more conjugated aromatic
groups, one or more conjugated heterocyclic groups (e.g., stilkene,
and/or bestriazenylamino-stilkene, and/or pyrazoline, and/or
courmarine type molecule or mixture thereof), one or more
conjugated carbon-carbon double bonds (e.g., carotene), or
combinations thereof. In one exemplary embodiment, the heat
transfer fluid colorant will comprise at least one of
diarylmethane, triphenylmethane, one or more conjugated aromatic
groups, azo, or combinations thereof. In one especially exemplary
embodiment, the heat transfer fluid colorant will comprise at least
one or more conjugated aromatic groups as a chromophore.
[0092] In another embodiment, the heat transfer fluid colorant will
comprise the reaction product of a non-conductive alkoxy compounds
and at least one chromophore such as described above. Illustrative
examples of suitable non-conductive alkoxy compounds include those
having from 1 to 30 carbons. Illustrative alkoxy compounds include
ethylene oxide, propylene oxide, butylene oxide, and the like, with
ethylene oxide and propylene oxide being particularly suitable. In
one embodiment, the chromophore reacted with the alcohol will be
selected from the group consisting of anthraquinone,
triphenylmethane, diphenylmethane, diarylmethane, triarylmethane,
azo containing compounds, disazo containing compounds, trisazo
containing compounds, diazo containing compounds, and combinations
thereof.
[0093] Alternatively, suitable heat transfer fluid colorants may be
described as those of the formula:
R{A.sub.k[(B).sub.nR.sup.1].sub.m}.sub.x
wherein R is an organic chromophore selected from the group
consisting of anthraquinone, triphenylmethane, diphenylmethane, azo
containing compounds, disazo containing compounds, trisazo
containing compounds, diazo containing compounds, xanthene,
acridine, indene, phthalocyanine, azaannulene, nitroso, nitro,
diarylmethane, triarylmethane, methine, indamine, azine, oxazine,
thiazine, quinoline, indigoid, indophenol, lactone, aminoketone,
hydroxyketone, stilbene,thiazole, two or more conjugated aromatic
groups, two or more conjugated heterocyclic groups, or combinations
thereof; A is a linking moiety in said chromophore and is selected
from the group consisting of O, N or S; k is 0 or 1; B is selected
from the group consisting of one or more alkyleneoxy or alkoxy
groups containing from 1 to 8 carbon atoms; n is an interger of
from 1 to 100; m is 1 or 2; x is an integer of from 1 to 5; and
R.sub.1 is selected from the group consisting of H, C.sub.1-C.sub.6
alkyl or alkoxy groups containing from 1 to 8 carbon atoms, or
combinations thereof.
[0094] In one exemplary embodiment, suitable heat transfer fluid
colorants are those colorants of the above formula wherein B is
selected from the group of one or more alkyleneoxy constitutuents
containing from 2 to 4 carbon atoms, n is from 1 to 30, m is 1 or
2, X is preferably 1 or 2, and R1 is preferably H or a
C.sub.1-C.sub.4 alkyl or alkoxy groups containing from 1 to 6
carbon atoms. In one exemplarly embodiment, suitable heat transfer
fluid colorants are those containing one or more of diarylmethane,
triarylmethane, triphenylmethane, diphenylmethane, conjugated
aromatic groups or conjugated carbon-carbon double bonds or a
combination thereof, since such are not expected to contribute to
conductivity increase from the chromophore. In other words, these
chromophore structure have no groups that will hydrolyze. Among the
listed linking group, O may also be less likely to hydrolyze in
aqueous solution.
[0095] The heat transfer fluid colorants may be prepared by various
known methods as are described above with respect to the treatment
colorants.
[0096] Commercially available examples of suitable heat transfer
fluid colorants for use in colored heat transfer fluids suitable
for use in the disclosed fuel cells and fuel cell systems include
Liquitint.RTM. Red ST or other similar polymeric colorants from
Milliken Chemical of Spartanburg, S.C., USA, or colorants (e.g.,
Liquitint.RTM. Blue RE) from Chromatech of Canton, Mich., USA.
Other illustrative colorants include the following:
Liquitint.RTM.Red ST, Liquitint.RTM.Blue RE, Liquitint.RTM.Red XC,
Liquitint.RTM.Patent Blue, Liquitint.RTM.Bright yellow,
Liquitint.RTM.Bright orange, Liquitint.RTM.Royal Blue,
Liquitint.RTM.Blue N-6, Liquitint.RTM.Bright Blue,
Liquitint.RTM.Supra Blue, Liquitint.RTM.Blue HP, Liquitint.RTM.Blue
DB, Liquitint.RTM.Blue II, Liquitint.RTM.Exp. Yellow 8614-6,
Liquitint.RTM.Yellow BL, Liquitint.RTM.Yellow II,
Liquitint.RTM.Sunbeam Yellow, Liquitint.RTM.Supra yellow,
Liquitint.RTM.Green HMC, Liquitint.RTM.violet, Liquitint.RTM.Red
BL, Liquitint.RTM.Red RL, Liquitint.RTM.Cherry Red,
Liquitint.RTM.Red II, Liquitint.RTM.Teal, Liquitint.RTM.Yellow LP,
Liquitint.RTM. Violet LS, Liquitint.RTM.Crimson,
Liquitint.RTM.Aquamarine, Liquitint.RTM.Green HMC,
Liquitint.RTM.Red HN, Liquitint.RTM.Red ST, as well as combinations
thereof.
[0097] In one exemplary embodiment, the heat transfer fluid
colorant will be at least one of Liquitint.RTM. Red ST from
Milliken, Liquitint.RTM. Red XC from Chromatech, Liquitint.RTM.
Patent Blue from Milliken, Chromatint.RTM. Yellow 1382 from
Chromatech or Liquitint.RTM. Blue.RTM. RE from Chromatech, while in
an especially exemplary embodiment, the non-conductive colorant
will be Liquitint.RTM. Blue RE from Chromatech.
[0098] In one embodiment, the heat transfer fluid colorant will be
present in the colored fuel cell heat transfer fluid in an amount
of from 0.0001 to 0.2% by weight, based on the total amount of the
colored heat transfer fluid. In another embodiment, the heat
transfer fluid colorant will be present in the heat transfer fluid
in an amount of from 0.0005-0.1% by weight, based on the total
amount of the heat transfer fluid, while in one exemplary
embodiment, the heat transfer fluid colorant will be used in an
amount of from 0.0005 to 0.05% by weight, based on the total amount
of the heat transfer fluid.
[0099] Illustrative examples of suitable alcohols for use in the
disclosed heat transfer fluids are methanol, ethanol, propanol,
butanol, furfurol, ethylene glycol, diethylene glycol, triethylene
glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene
glycol, butylene glycol, glycrol, monoethylether of glycerol,
dimethyl ether of glycerol, 1,2,6-hexanetriol, trimethylolpropane,
methoxyethanol, or a combination comprising one or more of such
alcohols. Illustrative examples of particularly suitable alcohols
include ethylene glycol, propylene glycol, butyl glycol, glycerol,
diethylene glycol, and the like, as well as mixtures thereof. In
one embodiment, the alcohol will be ethylene glycol or
1,2-propylene glycol or 1,3-propylene glycol, while in one
exemplary embodiment; the disclosed colored heat transfer fluid
will comprise ethylene glycol.
[0100] In one embodiment, the alcohol will be present in the heat
transfer fluid in an amount of from 10-99.9% by weight, based on
the total amount of the colored heat transfer fluid. In another
embodiment, the at least one alcohol will be present in the heat
transfer fluid in an amount of from 20-99.9% by weight, based on
the total amount of the heat transfer fluid, while in one exemplary
embodiment, the at least one alcohol will be used in an amount of
from 20 to 99.9% by weight, based on the total amount of the
colored heat transfer fluid.
[0101] As previously indicated, water may be present in the
disclosed colored fuel cell heat transfer fluids. In one exemplary
embodiment, deionized water will be used. In one embodiment, water
will be present in the colored heat transfer fluid in an amount of
from 0.1-90% by weight, based on the total amount of the heat
transfer fluid. In another embodiment, water will be present in the
heat transfer fluid in an amount of from 0.1-80% by weight, based
on the total amount of the heat transfer fluid, while in one
exemplary embodiment, water will be used in an amount of from 0.1
to 70% by weight, based on the total amount of the colored heat
transfer fluid.
[0102] For example, water may not be present in the concentrate
version of a heat transfer fluid at all, i.e., 0 wt % but may be
present in some concentrates in amounts up to about 50 wt %, in
others up to 20 wt %, based on the total weight of the concentrate.
With regards to diluted heat transfer fluids; water may be present
in amounts of from 20 wt % up to 90% wt.
[0103] Suitable corrosion inhibitors include aluminum and aluminum
based alloy corrosion inhibitors, copper and copper based alloy
corrosion inhibitors, ferrous metal corrosion inhibitors, such as,
azole derivatives, and amines such as ethanolamine, diethanol
amines, triethanolamine, octylamine and morpholine, orthosilicate
ester as described in US2004/0028971A1 and the like.
[0104] In one embodiment, one or more corrosion inhibitors will be
present in the heat transfer fluid in an amount of from 0.0 to
10.0% by weight, based on the total amount of the colored heat
transfer fluid. In another embodiment, one or more corrosion
inhibitors will be present in the heat transfer fluid in an amount
of from 0.0-5% by weight, based on the total amount of the heat
transfer fluid, while in one exemplary embodiment, one or more
corrosion inhibitors will be used in an amount of from 0.0 to 2% by
weight, based on the total amount of the colored heat transfer
fluid.
[0105] Suitable colored heat transfer fluids may also comprise
additional additives such as defoamers, surfactants, scale
inhibitors, dispersants, wetting agents, bittering agents, and the
like, in amounts of up to 10% by weight, based on the total amount
of the colored heat transfer fluid.
[0106] In one embodiment, suitable colored heat transfer fluids
will comprise from 20-99.9% by weight of at least one alcohol or an
alcohol mixture, from 0.1-80% by weigh of water, and from 0.0001 to
0.1% by weight of a non-conductive colorant, based on the total
amount of the heat transfer fluid, and 0.0 to 10% by weight of
other optional heat transfer fluid additives. In one exemplary
embodiment, the disclosed heat transfer fluids will comprise from
20-99.9% by weight of at least one alcohol or an alcohol mixture,
from 0.1-80% by weigh of water, and from 0.0001 to 0.1% by weight
of a non-conductive colorant, and 0.0 to 10% by weight of other
heat transfer fluid additives based on the total amount of the heat
transfer fluid.
[0107] In another exemplary embodiment, suitable heat transfer
fluids will comprise from 20-99.9% by weight of at least one
alcohol, from 0.1-80% by weigh of water, from 0 to 5% by weight of
one or more corrosion inhibitors, and from 0.0001 to 0.1% by weight
of a non-conductive colorant and an optional antifoam agent in an
amount of from 0.0 to 0.1% by weight, based on the total amount of
the heat transfer fluid.
[0108] The colored heat transfer fluids may be prepared by mixing
the components together. Normally, the alcohol and water are
preferably mixed together first. The other additives are then added
to the alcohol-water mixture by mixing and adequate stirring.
[0109] The disclosed colorant treated ion exchange resins are
advantageous in that they are capable of removing ionic species
from a treatment solution or heat transfer fluid, maintaining low
conductivity in a colored heat transfer fluid and providing color
to a colored heat transfer fluid. The disclosed colorant treated
ion exchange resins are also advantageous in that they are capable
of simultaneously removing ionic species from a heat transfer
fluid, maintaining low conductivity in a colored heat transfer
fluid and providing color to a colored heat transfer fluid.
[0110] The singular forms "a", "an" and "the" include plural
referents unless the context clearly dictates otherwise. "Optional"
or "optionally" means that the subsequently described event or
circumstance may or may not occur, and that the description
includes instances where the event occurs and instances where it
does not. The modifier "about" used in connection with a quantity
is inclusive of the stated value and has the meaning dictated by
the context (e.g., includes the degree of error associated with
measurement of the particular quantity).
[0111] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
EXAMPLE 1
[0112] The conductivity as a function of colorant concentration in
de-ionized water at room temperature was evaluated per Table 1.
Solutions of the various colorants identified below were mixed in
de-ionized water at room temperature under simple agitation.
Conductivity was measured via a Traceble.RTM. bench conductivity
meter manufactured by Control Company, Friendswood, Tex., USA.
TABLE-US-00001 TABLE 1 Concentration of Colorant in Solution
Conductivity of Solution Colorant Name (mg/L) (.mu.S/cm)
Uranine.sup.1 Blank 0.30 20 3.36 50 8.27 100 16.67 Liquitint .RTM.
Red ST Blank 0.27 20 0.45 50 0.58 100 0.65 Liquitint .RTM. Bright
Blank 0.28 Yellow 20 1.97 50 4.35 100 8.36 Liquitint .RTM. Patent
Blue Blank 0.30 20 1.79 50 3.95 100 7.41 Liquitint .RTM. Bright
Blank 0.28 Orange 20 1.11 50 2.23 100 4.05 Acid Red 52.sup.1 Blank
0.25 20 5.98 50 13.4 100 33.9 .sup.1Acid Red 52 is commercially
available from Chromatech of Canton, MI. Uranine is commercially
available from Honeywell-CPG of Danbury, CT
[0113] It can be seen that the two commonly used antifreeze dyes,
i.e., Uranine and Acid Red 52 dye possess higher conductivity than
the evaluated Liquitint.RTM. dyes at equivalent concentrations.
EXAMPLE 2
[0114] The Liquitint.RTM. Red ST dye was also found to be stable at
80.degree. C. in 50% Ethylene glycol+50% de-ionized water (all as
volume %). A test was done by dissolving 20 ppm Liquitint.RTM. Red
into 50% ethylene glycol+50% de-ionized water solution (V/V). The
solution was separated into two parts in two clean beakers. One was
heated at 80.degree. C. for about 45 minutes. The conductivity of
the two solutions before and after the heating was recorded. There
was no noticeable change in the solutions. The conductivity of the
solution showed essentially no change before and after heating
(Blank and before heating at 80.degree. C.: 0.45 .mu.S/cm; kept at
80.degree. C. for .about.45 min and cooled down to room
temperature: 0.48 .mu.S/cm).
EXAMPLE 3
[0115] The effect of the non-conductive dyes upon the corrosion of
metals in a fuel cell heat transfer system was evaluated.
[0116] Metal samples according to the following were cleaned with
cleaner and de-ionized water before separating into two identical
sets and put in 2 clean glass flasks. Each flask contained 4 cast
Al coupons, 4 brass coupons, 4 stainless steel (SS316) coupons, 2
brazed Al coupon, 2 silicone gasket, 4 Viton 0-rings. The total
surface area was about 392 square centimeters. 300 ml 50% ethylene
glycol+50% (volume) DI water was added into one flask while 300 ml
50% ethylene glycol+50% (volume) DI water+20 ppm Liquitint.RTM. Red
ST was added to the second flask.
[0117] The conductivity of each solution was recorded as a function
of time. Since corrosion of the metals will generate ionic species
and increase the solution conductivity, the conductivity of the
solution was used to indicate the extent of the corrosion of the
metal samples in the flasks. The results obtained are listed below
in Table 2.
TABLE-US-00002 TABLE 2 Conductivity of the Conductivity of Solution
with 20 ppm the Solution Liquitint .RTM. Red ST without the Dye
Time (.mu.S/cm) (.mu.S/cm) 0 min 0.50 0.49 20 min 0.50 0.50 40 min
0.51 0.49 100 min 0.54 0.52 16 hours 0.83 0.71
[0118] Little difference in conductivity was observed, indicating
that 20 ppm Liquitint.RTM. Red ST has no effect on metal corrosion
under the test conditions. Thus, Liquitint.RTM. Red ST dye added to
glycol/water mixture in an amount of 20 ppm did not enhance the
corrosion of metals likely to be present in fuel cell heat transfer
systems.
EXAMPLE 4
[0119] The removal of a colorant suitable for use as either a
treatment colorant or a heat transfer fluid colorant by a mixed bed
resin was demonstrated.
[0120] 50 mg/l Liquitint.RTM. Red ST was added to 200 g of 50% wt
ethylene glycol in DI water solution in a beaker. The solution was
separated into two equal parts. 2 g of Rohm & Haas Amberjet
UP6040 mixed bed resin was added to one part of the solution. The
solution was under constant stirring by the use of a clean Teflon
coated magnet bar at room temperature. After about 16 hours, the
initially red solution became faintly red color indicating that the
resin had removed most (e.g., greater than about 95%) of the
Liquitint.RTM. Red ST colorant.
EXAMPLE 5
[0121] The conductivity of various colorants suitable for use as
treatment and/or heat transfer fluid colorants was evaluated. 50%
wt ethylene glycol+50% wt DI water solutions at room temperature
were prepared with various colorants at typical use concentrations
as indicated below in Table 3.
TABLE-US-00003 TABLE 3 Concentration Conductivity Dye (mg/L)
(.mu.S/cm) Stock Solution 50% Ethylene Glycol Conductivity 0.40
.mu.S/cm 85.degree. C. Chromatint Yellow 1382 100 1.37 L85000
Liquitint .RTM. Patent Blue 100 2.75 Liquitint .RTM. Blue RE 100
0.56 Liquitint .RTM. Red XC 100 0.46 Stock Solution 50% Ethylene
Glycol Conductivity 0.43 .mu.S/cm C. Chromatint Yellow 1382 50 mg/L
0.91 L85000 Liquitint .RTM. Patent Blue 50 mg/L 1.61 Liquitint
.RTM. Blue RE 50 mg/L 0.53 Liquitint .RTM. Red XC 50 mg/L 0.45
Stock Solution 50% Ethylene Glycol Conductivity 0.42 .mu.S/cm
36.degree. C. Chromatint Yellow 1382 20 0.63 L85000 Liquitint .RTM.
Patent Blue 20 0.89
[0122] It can be seen that the various colorants were suitable in
as much as they provided heat transfer fluid solutions having low
conductivity.
EXAMPLE 6
[0123] The compatibility of various treatment/heat transfer fluid
colorants having low conductivity with mixed bed ion exchange
resins with cation resin in H.sup.+ form and the anion resin in
OH.sup.- form was evaluated.
[0124] 50 mg/l colorant solution in 50% wt ethylene glycol+50% wt
DI water was prepared. 100 g of the solution was added into a
beaker. 2 g of MTO-Dowex.TM. MR-3 LC NG mixed bed resin was added
to the solution. The solution was under constant stirring by the
use of a clean teflon coated magnet bar at room temperature. The
concentrations of the colorants in the solution were determined by
UV-Vis spectroscopic measurements. The colorants used in the tests
were L83002 Liquintint.RTM. Red XC and L85071 Liquintint.RTM. Blue
RE supplied by Chromatech. The maximum absorption peak at 535 nm
was used to determine the concentration of Liquitint.RTM. Red XC
dye. The maximum absorption peak at 632 nm was used to determine
the concentration of Liquitint.RTM.Blue RE dye. The following
results were obtained.
[0125] After 21 hours, the concentration of L83002
Liquitint.RTM.Red XC in 50% EG was reduced to 11 ppm from an
initial concentration of 50 ppm, indicating it's suitability as
either a treatment colorant or a heat transfer fluid colorant. The
concentration of L85071 Liquitint.RTM.Blue RE had little change,
i.e., 48 ppm at 21.5 hours vs. an initial concentration of 50 ppm,
indicating that the L85071 Liquitint.RTM.Blue RE could be used as
non-conductive heat transfer fluid colorant.
EXAMPLE 7
[0126] A colorant treated mixed bed ion exchange resin according to
the invention was evaluated.
[0127] An aqueous solution of Liquitint.RTM. Red ST from Milliken
was used to treat a mixed ion exchange resin. The resin was
MTO-Dowex.TM. MR-3 LC NG wherein the cation resin is in H.sup.+
form and the anion resin is in OH.sup.- form. Ten grams of
MTO-Dowex.TM.MR-3 LC NG was added into one liter 5 g/l
Liquitint.RTM. Red ST dissolved in 50% ethylene glycol under
constant magnetic bar stirring at room temperature. After 24 hours,
another 5 g of the Liquitint.RTM.Red ST dye were added to the
solution. The dye exchange reaction was allowed to continue for
more than 24 hours before the resin was separated from the dye
containing 50% EG solution. The colorant saturated was rinsed with
a large amount of DI water to wash away the excessive colorant
solution (until the rinse water became colorless) and dried with a
clean paper towel and stored in a clean glass bottle. Since the
color of solution did not show visible change after the first 24
hours of the treatment, the colorant loading on the resin was
estimated to be closed to saturation at the end of the treatment,
e.g., the colorant loading on the resin was likely to be higher
than 90% capacity loading of the resin for the colorant.
[0128] One gram of colorant saturated resin was added to two 100 g
samples of a 50% ethylene glycol aqueous solution respectively
containing 30 ppm NaCl or 30 ppm sodium formate+30 ppm sodium
acetate. The solutions were stirring constantly with a magnetic
bar. The tests were conducted at room temperature. The solution
conductivity was measured as a function of time. The following
results as set forth in FIG. 2 were obtained. Generally, the
solution became red soon after the resin was added into the salt
containing solutions. The color became more prominent as time
increased, showing that the disclosed colorant-saturated resin is
capable of removing the ionic species from the solutions while
providing a distinct color to the 50% wt ethylene glycol aqueous
solution. This illustrates that colorant treated ion exchange
resins made according to the instant disclosures are capable of
simultaneously removing ionic species from a 50% ethylene glycol
aqueous solution, maintaining low conductivity in the heat transfer
fluid solution and providing color to the solution.
* * * * *