U.S. patent application number 12/500036 was filed with the patent office on 2009-10-29 for heat transfer system, fluid, and method.
This patent application is currently assigned to HONEYWELL INTERNATIONAL INC.. Invention is credited to Filipe J. Marinho, Bo Yang.
Application Number | 20090266519 12/500036 |
Document ID | / |
Family ID | 41507756 |
Filed Date | 2009-10-29 |
United States Patent
Application |
20090266519 |
Kind Code |
A1 |
Marinho; Filipe J. ; et
al. |
October 29, 2009 |
HEAT TRANSFER SYSTEM, FLUID, AND METHOD
Abstract
Disclosed herein is a heat transfer system comprising a
circulation loop defining a flow path for a heat transfer fluid,
and a heat transfer fluid comprising a liquid coolant, a siloxane
corrosion inhibitor of formula R3-Si--[O--Si(R)2]x-OSiR3, wherein R
is independently an alkyl group or a polyalkylene oxide copolymer
of 1 to 200 carbons, x is from 0 to 100, and further wherein at
least one alkyl group and at least one polyalkylene oxide copolymer
are present, and a non-conductive polydiorganosiloxane antifoam
agent, wherein the conductivity of the heat transfer fluid is less
than about 100 .mu.S/cm, and wherein the heat transfer system
comprises aluminum, magnesium, or a combination thereof, in
intimate contact with the heat transfer fluid.
Inventors: |
Marinho; Filipe J.;
(Danbury, CT) ; Yang; Bo; (Ridgefield,
CT) |
Correspondence
Address: |
HONEYWELL INTERNATIONAL INC.;PATENT SERVICES
101 COLUMBIA ROAD, P O BOX 2245
MORRISTOWN
NJ
07962-2245
US
|
Assignee: |
HONEYWELL INTERNATIONAL
INC.
Morristown
NJ
|
Family ID: |
41507756 |
Appl. No.: |
12/500036 |
Filed: |
July 9, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11222024 |
Sep 8, 2005 |
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12500036 |
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60607898 |
Sep 8, 2004 |
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61080033 |
Jul 11, 2008 |
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Current U.S.
Class: |
165/104.19 |
Current CPC
Class: |
C23F 11/08 20130101;
C23F 11/173 20130101; C09K 5/10 20130101; C23F 11/10 20130101; C02F
1/42 20130101; C02F 2303/08 20130101 |
Class at
Publication: |
165/104.19 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Claims
1. A heat transfer system, comprising: a circulation loop defining
a flow path for a heat transfer fluid; and a heat transfer fluid,
comprising: a liquid coolant; a siloxane corrosion inhibitor of
formula R.sub.3--Si--[O--Si(R).sub.2].sub.x--OSiR.sub.3, wherein R
is independently an alkyl group or a polyalkylene oxide copolymer
of 1 to 200 carbons, x is from 0 to 100, and further wherein at
least one alkyl group and at least one polyalkylene oxide copolymer
are present; and a non-conductive polydiorganosiloxane antifoam
agent; wherein the conductivity of the heat transfer fluid is less
than about 100 .mu.S/cm; and wherein the heat transfer system
comprises aluminum, magnesium, or a combination thereof, in
intimate contact with the heat transfer fluid.
2. The heat transfer system of claim 1, wherein the conductivity of
the heat transfer fluid is about 0.02 to about 5 .mu.S/cm.
3. The heat transfer system of claim 1, wherein the liquid coolant
comprises an alcohol, water, or a combination thereof.
4. The heat transfer system of claim 3, wherein the alcohol
comprises methanol, ethanol, propanol, butanol, furfurol,
tetrahydrofurfurol, ethoxylated furfurol, an alkoxy alkanol,
ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol,
butylene glycol, glycerol, glycerol-1,2-dimethyl ether,
glycerol-1,3-dimethyl ether, monoethylether of glycerol, sorbitol,
1,2,6-hexanetriol, trimethylol propane, or a combination
thereof.
5. The heat transfer system of claim 1, wherein the non-conductive
polydiorganosiloxane antifoam agent comprises a
polydiorganosiloxane emulsion based antifoam agent.
6. The heat transfer system of claim 1, wherein the heat transfer
fluid further comprises an azole comprising a pyrrole, a pyrazole,
an imidazole, a triazole, a thiazole, a tetrazole, or a combination
thereof, according to formulas (I)-(IV): ##STR00002## wherein
R.sup.1 and R.sup.2 are independently a hydrogen atom, a halogen
atom such, a C.sub.1-20 alkyl or cycloalkyl group, SR.sup.3,
OR.sup.3, or NR.sup.3.sub.2, wherein R.sup.3 is independently a
hydrogen atom, a halogen atom, or a C.sub.1-20 alkyl or cycloalkyl
group, X is independently N or CR.sup.2, and Y is independently N
or CR.sup.1.
7. The heat transfer system of claim 1, wherein the heat transfer
fluid further comprises a non-ionic corrosion inhibitor, a
tetraalkylorthosilicate ester, a non-conductive colorant, a wetting
agent, a biocide, a bitterant, a non-ionic dispersant, or a
combination thereof.
8. The heat transfer system of claim 1, further comprising an ion
exchange resin in fluid communication with the heat transfer
fluid.
9. The heat transfer system of claim 8, wherein the ion exchange
resin is pre-treated with a corrosion inhibiting composition
comprising a siloxane corrosion inhibitor, an azole, or a
combination thereof.
10. The heat transfer system of claim 1, in the form of an internal
combustion engine, a fuel cell, a battery, a solar cell, a solar
panel, a photovoltaic cell, or a combination thereof.
11. A heat transfer fluid, comprising: a liquid coolant; a siloxane
corrosion inhibitor of formula
R.sub.3--Si--[O--Si(R).sub.2].sub.x--OSiR.sub.3, wherein R is
independently an alkyl group or a polyalkylene oxide copolymer of 1
to 200 carbons, x is from 0 to 100, and further wherein at least
one alkyl group and at least one polyalkylene oxide copolymer are
present; and a non-conductive polydiorganosiloxane antifoam agent;
wherein the conductivity of the heat transfer fluid is less than
about 100 .mu.S/cm.
12. The heat transfer fluid of claim 11, wherein the conductivity
is less than about 25 .mu.S/cm.
13. The heat transfer fluid of claim 12, wherein the conductivity
is about 0.02 to about 5 .mu.S/cm.
14. The heat transfer fluid of claim 11, wherein the liquid coolant
comprises an alcohol, water, or a combination thereof.
15. The heat transfer fluid of claim 14, wherein the alcohol
comprises a monohydric alcohol, a polyhydric alcohol, or a
combination thereof.
16. The heat transfer fluid of claim 15, wherein the monohydric
alcohol comprises methanol, ethanol, propanol, butanol, furfurol,
tetrahydrofurfurol, ethoxylated furfurol, an alkoxy alkanol, or a
combination thereof.
17. The heat transfer fluid of claim 15, wherein the polyhydric
alcohol comprises ethylene glycol, diethylene glycol, triethylene
glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene
glycol, butylene glycol, glycerol, glycerol-1,2-dimethyl ether,
glycerol-1,3-dimethyl ether, monoethylether of glycerol, sorbitol,
1,2,6-hexanetriol, trimethylol propane, or a combination
thereof.
18. The heat transfer fluid of claim 11, wherein the siloxane
corrosion inhibitor comprises a polysiloxane, an organosilane
comprising a silicon-carbon bond, or a combination thereof.
19. The heat transfer fluid of claim 11, wherein the non-conductive
polydiorganosiloxane antifoam agent comprises a
polydiorganosiloxane emulsion based antifoam agent.
20. The heat transfer fluid of claim 11, further comprising a
secondary corrosion inhibitor.
21. The heat transfer fluid of claim 20, wherein the secondary
corrosion inhibitor comprises an azole, colloidal silica, or a
combination thereof.
22. The heat transfer fluid of claim 21, wherein the secondary
corrosion inhibitor comprises the azole, and further wherein the
azole comprises a pyrrole, a pyrazole, an imidazole, a triazole, a
thiazole, a tetrazole, or a combination thereof, according to
formulas (I)-(IV): ##STR00003## wherein R.sup.1 and R.sup.2 are
independently a hydrogen atom, a halogen atom such, a C.sub.1-20
alkyl or cycloalkyl group, SR.sup.3, OR.sup.3, or NR.sup.3.sub.2,
wherein R.sup.3 is independently a hydrogen atom, a halogen atom,
or a C.sub.1-20 alkyl or cycloalkyl group, X is independently N or
CR.sup.2, and Y is independently N or CR.sup.1.
23. The heat transfer fluid of claim 22, wherein the azole is
selected from the group consisting of pyrrole, methylpyrrole,
pyrazole, dimethylpyrazole, benzotriazole, tolyltriazole, methyl
benzotriazole, butyl benzotriazole, mercaptobenzothiazole,
benzimidazole, halo-benzotriazole, tetrazole, methyl tetrazole,
mercapto tetrazole, thiazole, 2-mercaptobenzothiazole and a
combination thereof.
24. The heat transfer fluid of claim 11, further comprising a
non-ionic corrosion inhibitor, a tetraalkylorthosilicate ester, a
non-conductive colorant, a wetting agent, a biocide, a bitterant, a
non-ionic dispersant, or a combination thereof.
25. A heat transfer method, comprising: contacting a heat transfer
system with a heat transfer fluid; wherein the heat transfer system
comprises: a circulation loop defining a flow path for the heat
transfer fluid; and aluminum, magnesium, or a combination thereof;
wherein the heat transfer fluid comprises: a liquid coolant; a
siloxane corrosion inhibitor of formula
R.sub.3--Si--[O--Si(R).sub.2].sub.x--OSiR.sub.3, wherein R is
independently an alkyl group or a polyalkylene oxide copolymer of 1
to 200 carbons, x is from 0 to 100, and further wherein at least
one alkyl group and at least one polyalkylene oxide copolymer are
present; and a non-conductive polydiorganosiloxane antifoam agent;
wherein the conductivity of the heat transfer fluid is less than
about 100 .mu.S/cm; and wherein the aluminum, magnesium, or
combination thereof is in intimate contact with the heat transfer
fluid.
Description
[0001] This application is a continuation-in-part of application
Ser. No. 11/222,024, filed Sep. 8, 2005, which claims the benefit
of U.S. provisional application No. 60/607,898, filed Sep. 8, 2004,
both of which are incorporated by reference herein in their
entirety. This application also claims the benefit of U.S.
provisional application No. 61/080,033 filed on Jul. 11, 2008,
which is incorporated by reference herein in its entirety.
BACKGROUND
[0002] This disclosure generally relates to a heat transfer system,
heat transfer fluid, and heat transfer method.
[0003] The operation of a power source generates heat. A heat
transfer system, in communication with the power source, regulates
the generated heat, and ensure that the power source operates at an
optimum temperature. The heat transfer system generally comprises a
heat transfer fluid that facilitates absorbing and dissipating the
heat from the power source. Heat transfer fluids, which generally
comprise water and a glycol, are in intimate contact with one or
several metallic parts that are prone to corrosion. Thus, several
corrosion inhibitors are added to the heat transfer fluid in order
to protect the metallic parts from corrosion. Traditional heat
transfer fluids can exhibit extremely high conductivities, often in
the range of 3000 microsiemens per centimeter (PS/cm) or more. This
high conductivity produces adverse effects on the heat transfer
system by promoting corrosion of metal parts, and also in the case
of power sources where the heat transfer system is exposed to an
electrical current, such as in fuels cells or the like, the high
conductivity can lead to short circuiting of the electrical current
and to electrical shock.
[0004] Aluminum, magnesium, and their alloys, are increasingly used
in the manufacture of several components of a heat transfer system.
They are advantageous due to their light weight, high strength, and
relative ease of manufacture, among others. Aluminum, magnesium,
and their alloys can be used in heat transfer systems of internal
combustion engines and alternative power sources. However,
magnesium, aluminum, and their alloys are highly susceptible to
corrosion when in contact with traditional heat transfer fluids
with high conductivity. In addition, the foaming of traditional
heat transfer fluids further contributes to the corrosion of
aluminum, magnesium, and their alloys.
[0005] Therefore, a need exists for heat transfer systems and
fluids intended for use therein, wherein the heat transfer systems
comprise aluminum, magnesium, or their alloys, in intimate contact
with the heat transfer fluid. The heat transfer fluids
advantageously have low conductivity and good foaming
properties.
SUMMARY
[0006] The above-described and other drawbacks are alleviated by a
heat transfer system, comprising a circulation loop defining a flow
path for a heat transfer fluid, and a heat transfer fluid
comprising a liquid coolant, a siloxane corrosion inhibitor of
formula R3-Si--[O--Si(R)2]x-OSiR3, wherein R is independently an
alkyl group or a polyalkylene oxide copolymer of 1 to 200 carbons,
x is from 0 to 100, and further wherein at least one alkyl group
and at least one polyalkylene oxide copolymer are present, and a
non-conductive polydiorganosiloxane antifoam agent, wherein the
conductivity of the heat transfer fluid is less than about 100
.mu.S/cm, and wherein the heat transfer system comprises aluminum,
magnesium, or a combination thereof, in intimate contact with the
heat transfer fluid.
[0007] In one embodiment, a heat transfer fluid comprises a liquid
coolant, a siloxane corrosion inhibitor of formula
R3-Si--[O--Si(R)2]x-OSiR3, wherein R is independently an alkyl
group or a polyalkylene oxide copolymer of 1 to 200 carbons, x is
from 0 to 100, and further wherein at least one alkyl group and at
least one polyalkylene oxide copolymer are present, and a
non-conductive polydiorganosiloxane antifoam agent, wherein the
conductivity of the heat transfer fluid is less than about 100
.mu.S/cm.
[0008] In another embodiment, a heat transfer method comprises
contacting a heat transfer system with a heat transfer fluid,
wherein the heat transfer system comprises a circulation loop
defining a flow path for the heat transfer fluid, and aluminum,
magnesium, or a combination thereof, wherein the heat transfer
fluid comprises a liquid coolant, a siloxane corrosion inhibitor of
formula R3-Si--[O--Si(R)2]x-OSiR3, wherein R is independently an
alkyl group or a polyalkylene oxide copolymer of 1 to 200 carbons,
x is from 0 to 100, and further wherein at least one alkyl group
and at least one polyalkylene oxide copolymer are present, and a
non-conductive polydiorganosiloxane antifoam agent, wherein the
conductivity of the heat transfer fluid is less than about 100
.mu.S/cm, and wherein the aluminum, magnesium, or combination
thereof is in intimate contact with the heat transfer fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Referring now to the drawings wherein like elements are
numbered alike in several FIGURES:
[0010] FIG. 1 is a schematic diagram of one embodiment of the heat
transfer system; and
[0011] FIG. 2 is a schematic diagram of another embodiment of the
heat transfer system.
DETAILED DESCRIPTION
[0012] Surprisingly, the present inventors have discovered that a
heat transfer fluid comprising a liquid coolant, a siloxane
corrosion inhibitor, and a non-conductive polydiorganosiloxane
antifoam agent, is an effective low conductivity heat transfer
fluid that is advantageous for use in heat transfer systems where
the heat transfer fluid is in intimate contact with aluminum,
magnesium, or their alloys, and/or with power sources where the
heat transfer fluid is exposed to an electrical current. The
conductivity of the heat transfer fluid is advantageously less than
about 100 .mu.S/cm. In one advantageous embodiment, the heat
transfer fluid further comprises an azole.
[0013] As used herein, "aluminum" refers to aluminum metal, alloys
thereof, or a combination thereof, and "magnesium" refers to
magnesium metal, alloys thereof, or a combination thereof.
[0014] The liquid coolant comprises an alcohol, water, or a
combination of an alcohol and water. It is advantageous to use
deionized water, demineralized water, or a combination thereof,
which generally exhibit a conductivity lower than that of water
which has not been deionized or demineralized. The heat transfer
fluid can be a concentrated heat transfer fluid, that is, a heat
transfer fluid comprising a liquid coolant consisting essentially
of alcohols. Concentrated heat transfer fluids are advantageous for
storage and shipping. Concentrated heat transfer fluids can, if
desired, be combined with water prior to or after use in the heat
transfer system. The heat transfer fluid can, on the other hand, be
a diluted heat transfer fluid, that is, a heat transfer fluid
comprising alcohols and water. Both concentrated and diluted heat
transfer fluids are suitable for use in the heat transfer system.
In one embodiment, the heat transfer fluid comprises a concentrated
heat transfer fluid. In another embodiment, the heat transfer fluid
comprises a diluted heat transfer fluid.
[0015] Water can be present in the heat transfer fluid in an amount
of about 0.01 to about 90 weight percent (wt %), based on the total
weight of the heat transfer fluid. Specifically, water can be
present in the heat transfer fluid in an amount of about 0.5 to
about 70 wt %, and more specifically about 1 to about 60 wt %,
based on the total weight of the heat transfer fluid. The heat
transfer fluid can be free of water.
[0016] The alcohol comprises monohydric alcohols, polyhydric
alcohols, or mixtures of monohydric and polyhydric alcohols.
Non-limiting examples of monohydric alcohols include methanol,
ethanol, propanol, butanol, furfurol, tetrahydrofurfurol,
ethoxylated furfurol, alkoxy alkanols such as methoxyethanol, and
the like, and combinations comprising at least one of the foregoing
monohydric alcohols. Non-limiting examples of polyhydric alcohols
include, ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol (or 1,3-propanediol),
dipropylene glycol, butylene glycol, glycerol,
glycerol-1,2-dimethyl ether, glycerol-1,3-dimethyl ether,
monoethylether of glycerol, sorbitol, 1,2,6-hexanetriol,
trimethylol propane, and the like, and combinations comprising at
least one of the foregoing polyhydric alcohols.
[0017] The alcohol can be present in the heat transfer fluid in an
amount of about 10 to about 99.9 wt %, based on the total weight of
the heat transfer fluid. Specifically, the alcohol can be present
in the heat transfer fluid in an amount of about 30 to about 99.5
wt %, and more specifically about 40 to about 99 wt %, based on the
total weight of the heat transfer fluid.
[0018] Siloxane corrosion inhibitors comprise polysiloxanes or
organosilane compounds comprising a silicon-carbon bond, or
combinations thereof. Suitable polysiloxanes are those of the
formula R3-Si--[O--Si(R)2]x-OSiR3 wherein R is independently an
alkyl group or a polyalkylene oxide copolymer of 1 to 200 carbons
and x is from 0 to 100, more specifically 2 to 90, more
specifically 3 to 80, more specifically 4 to 70, and even more
specifically 5 to 60.
[0019] In one exemplary embodiment, the siloxane corrosion
inhibitors comprise polysiloxanes or organosilane compounds
comprising a silicon-carbon bond, or a combination thereof, and
further comprising at least one group that is a polyalkylene oxide
copolymer of one or more alkylene oxides having from 2 to 6
carbons, specifically from 2 to 4 carbons. In another exemplary
embodiment, the siloxane corrosion inhibitor is of the formula
R3-Si--[O--Si(R)2]x-OSiR3 wherein R is independently an alkyl group
or a polyalkylene oxide copolymer of 1 to 200 carbons and x is as
discussed above, and further wherein at least one alkyl group and
at least one polyalkylene oxide copolymer.
[0020] Non-limiting examples of commercially available
polysiloxanes for use herein include the SILWET siloxanes from GE
Silicones/OSi Specialties, and other similar siloxane-polyether
copolymers available from Dow Corning or other suppliers. In one
exemplary embodiment, siloxane corrosion inhibitors comprise SILWET
L-77, SILWET L-7657, SILWET L-7650, SILWET L-7600, SILWET L-7200,
SILWET L-7210 or the like.
[0021] Organosilane compounds comprise a silicon-carbon bond
capable of hydrolyzing in the presence of water to form a silanol,
that is, a compound comprising silicon hydroxide. Organosilane
compounds can be of the formula R'Si(OZ)3 wherein R' and Z are
independently an aromatic group, an alkyl group, a cycloalkyl
group, an alkoxy group, or an alkenyl group, and can comprise a
heteroatom such as N, O, or the like, in the form of functional
groups such as amino groups, epoxy groups, or the like. In one
embodiment, R' is an aromatic group, an alkyl group, a cycloalkyl
group, an alkoxy group, or an alkenyl group, and can comprise a
heteroatom such as N, O, or the like, in the form of functional
groups such as amino groups, epoxy groups, or the like, and Z is a
C1-C5 alkyl group.
[0022] Non-limiting examples of commercially available organosilane
compounds for use herein include the SILQUEST and FORMASIL
surfactants from GE Silicones/OSi Specialties, and other suppliers.
In an exemplary embodiment, siloxane corrosion inhibitors comprise
FORMASIL 891, FORMASIL 593, FORMASIL 433, SILQUEST Y-5560
(polyalkyleneoxidealkoxysilane), SILQUEST A-186
(2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane), SILQUEST A-187
(3-glycidoxypropyltrimethoxysilane), or other SILQUEST organosilane
compounds available from GE Silicones, Osi Specialties or other
suppliers and the like.
[0023] Non-limiting examples of other organosilane compounds for
use herein include 3-aminopropyltriethoxysilane,
N-2-(aminoethyl)-3-aminopropyltrimethoxysilane,
octyltriethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane,
methyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane,
3-mercaptopropyltrimethoxysilane, isobutyltrimethoxysilane,
phenyltrimethoxysilane, methyltrimethoxysilane, and those
organosilane compounds having a structure similar to the foregoing,
but varying numbers of carbon atoms.
[0024] The siloxane corrosion inhibitor can be present in the heat
transfer fluid in an amount of about 0.01 to about 10 wt %, more
specifically about 0.02 to about 2 wt %, based on the total weight
of the heat transfer fluid.
[0025] The non-conductive polydiorganosiloxane antifoam agents
comprise any polydiorganosiloxane antifoam agents. Specifically,
the non-conductive polydiorganosiloxane antifoam agents are those
where the terminal groups at the molecular chain are selected from
a trimethylsilyl group, a dimethylhydroxysilyl group, and a
combination thereof. In one exemplary embodiment, the
polydiorganosiloxane is polydimethylsiloxane. These antifoam agents
are effective at preventing the formation of foam in the heat
transfer fluid and/or eliminating foam that formed in the heat
transfer fluid. The polydiorganosiloxane antifoam agents are
advantageously emulsion based antifoam agents
[0026] In one exemplary embodiment, the polydimethylsiloxanes for
use herein has the formula (CH3)3SiO--(SiCH3)2O)m-Si(CH3)3, where m
is from 1 to 30,000.
[0027] Specifically, the polydiorganosiloxanes have a kinematic
viscosity of about 5 to about 100 million mm2/sec at 25.degree. C.
More specifically, the kinematic viscosity of the
polydimethylsiloxanes is about 10 to about 1,000,000 mm2/sec at
25.degree. C. and the average molecular weight is about 1000 to
about 200,000 Daltons.
[0028] Polydiorganosiloxanes for use herein also include
polydiethylsiloxanes, polydimethyl polydiphenyl siloxane
copolymers, polydimethyl-poly(chloropropyl methyl)siloxanes, and a
combination thereof.
[0029] Other polydiorganosiloxanes for use herein have the formula
(CH3)3SiO--(SiCH3)2O)x-(CH3GSiO)y-Si(CH3)3, wherein G comprises an
alkyleneoxide or a polyoxyalkylene group. Non-limiting examples of
G include oxyalkylene groups having the formula
--(CH2)z(OCH2CH2)mOH, --(CH2)z(OCH2CH2CH2)mOH,
--(CH2)zO(OCH2CH2)mH, --(CH2)zO(OCH2CH2CH2)mH,
--(CH2)z(OCH2CH2CH2)k(OCH2CH2)lOH,
--(CH2)zO(OCH2CH2CH2)k(OCH2CH2)lH,
--(CH2)z(OCH2CH2)k[OCH2C(CH3)H]lOH, --(CH2)z(OCH2CH2)mOCH3,
--(CH2)z(OCH2CH2)k[OCH2C(CH3)H]lOCH3, --(CH2)z(OCH2CH2)mOC(O)CH3,
--(CH2)z(OCH2CH2CH2)mOCH3, and
--(CH2)z(OCH2CH2)k[OCH2C(CH3)H]lOC(O)CH3, wherein x is an integer
of 1 to 700, y is an integer of 1 to 60, z is an integer of 2 to
15, and m, k and l are integers of 1 to 40. Mixture of the
above-described polydiorganosiloxanes can also be used.
[0030] The polydiorganosiloxane antifoam agent can further comprise
up to about 20 wt % of a finely divided filler. Non-limiting
examples of the finely divided filler include fumed, precipated,
and plasmatic TiO2, Al2O3, Al2O3/SiO2, ZrO2/SiO2, and SiO2.
Hydrocarbon waxes, triglycerides, long chain fatty alcohols, fatty
acid esters and finely divided polyolefin polymers, such as
polypropylene, polyisobutylene, are additional examples of fillers
for use herein. The finely divided filler can be hydrophilic or
hydrophobic. The filler can be hydrophobed during manufacturing of
the antifoam or independently. Various grades of silica having a
particle size of several nanometers to several microns and a
specific surface area of about 40 to about 1000 m2/g, more
specifically a specific surface area of about 50 to about 400 m2/g,
are commercially available and suitable for use as the filler in
the polydiorganosiloxane based antifoams.
[0031] In one exemplary embodiment, hydrophobized silica having a
specific surface area of about 50 to about 350 m2/g is used as the
filler. Non-limiting examples of silica fillers for use herein
include AEROSIL R 812, and R 812S from Evonik Degussa (Essen,
Germany), TULLANOX 503 and 1080 from Tulco (MA, U.S.A.), and
similar products from other suppliers.
[0032] The polydiorganosiloxane antifoam agent can further comprise
up to 20 wt % of a hydrophobic oil. Non-limiting examples of the
hydrophobic oil include mineral oil, hydrocarbon oils derived from
carbonaceous sources, such as petroleum, shale, and coal, and
equivalents thereof. Mineral oils include heavy white mineral oil
which is high in paraffin content, light white mineral oil,
petroleum oils such as aliphatic or wax-base oils, aromatic and
asphalt-base oils, mixed-base oils, petroleum derived oils such as
lubricants, engine oils, machine oils, and cutting oils, and
medicinal oils such as refined paraffin oil. The mineral oils are
available commercially from several suppliers, including, but not
limited to, Exxon Company (Houston, Tex.), and Shell Chemical
Company (Houston, Tex.). In one exemplary embodiment, the mineral
oil has a dynamic viscosity of about 1 to about 20 centipoise
("cP", 1 cP=1 mPas) at 25.degree. C.
[0033] The polydiorganosiloxane antifoam agent can further comprise
other components, such as polyalkylenoxide, water, alkylene glycol,
surfactants, antiseptic agents, and biocides, up to about 95 wt
%.
[0034] Non-limiting examples of commercially available
non-conductive polydimethylsiloxane based antifoam agents and
emulsions thereof include PC-5450NF from Performance Chemicals LLC,
XD-55 and XD-56 from CNC International, and Y-14865 from Momentive
Performance Materials.
[0035] The non-conductive polydiorganosiloxane antifoam agent can
be present in the heat transfer fluid in an amount of about 1 to
about 3000 parts per million (ppm), specifically about 100 to about
2000 ppm, more specifically about 200 to about 1000 ppm, based on
the total weight of the heat transfer fluid.
[0036] In one advantageous embodiment, the heat transfer fluid
further comprises an azole. Azoles for use herein include
five-membered heterocyclic compounds having 1 to 4 nitrogen atoms
as part of the heterocycle. Non-limiting examples of azoles include
pyrroles, pyrazoles, imidazoles, triazoles, thiazoles and
tetrazoles according to formulas (I)-(IV):
##STR00001##
wherein R.sup.1 and R.sup.2 are independently a hydrogen atom, a
halogen atom such, a C.sub.1-20 alkyl or cycloalkyl group,
SR.sup.3, OR.sup.3, or NR.sup.3.sub.2, wherein R.sup.3 is
independently a hydrogen atom, a halogen atom, or a C.sub.1-20
alkyl or cycloalkyl group, X is independently N or CR.sup.2, and Y
is independently N or CR.sup.1.
[0037] Non-limiting examples of azoles include pyrrole,
methylpyrrole, pyrazole, dimethylpyrazole, benzotriazole,
tolyltriazole, methyl benzotriazole such as 4-methyl benzotriazole
and 5-methyl benzotriazole, butyl benzotriazole,
mercaptobenzothiazole, benzimidazole, halo-benzotriazole such as
chloro-methylbenzotriazole, tetrazole, methyl tetrazole, mercapto
tetrazole, thiazole, 2-mercaptobenzothiazole and the like. In one
embodiment, the azole comprises benzotriazole, tolyltriazole,
mercaptobenzothiazole, or a combination thereof. In one exemplary
embodiment, the azole comprises benzotriazole. In another exemplary
embodiment, the azole comprises tolyltriazole.
[0038] The azole can be present in the heat transfer fluid in an
amount of 0.0001 to about 10 wt %, specifically about 0.01 to about
8 wt %, more specifically about 0.5 to about 4 wt %, based on the
total weight of the heat transfer fluid.
[0039] The heat transfer fluid can further comprise additional
corrosion inhibitors that are non-ionic. Non-limiting examples of
these additional corrosion inhibitors include fatty acid esters,
such as sorbitan fatty acid esters, polyalkylene glycols,
polyalkylene glycol esters, copolymers of ethylene oxide and
propylene oxide, polyoxyalkylene derivatives of sorbitan fatty acid
esters, or the like, or combinations thereof. The average molecular
weight of additional corrosion inhibitors is from about 55 to about
300,000 daltons, and more specifically from about 110 to about
10,000 daltons. Non-limiting examples of sorbitan fatty acid esters
include sorbitan monolaureates such as SPAN 20, ARLACEL 20, or
S-MAZ 20M1, sorbitan monopalmitates such as SPAN 40 or ARLACEL 40,
sorbitan monostearates such as SPAN 60, ARLACEL 60, or S-MAZ 60K,
sorbitan mono-oleate such as SPAN 80 or ARLACEL 80, sorbitan
monosesquioleate such as SPAN 83 or ARLACEL 83, sorbitan trioleate
such as SPAN 85 or ARLACEL 85, sorbitan tristearate such as S-MAZ
65K, sorbitan monotallate such as S-MAZ 90, or the like, or
combinations thereof. Non-limiting examples of polyalkylene glycols
include polyethylene gycols, polypropylene glycols, and
combinations thereof. Non-limiting examples of polyethylene glycols
for use herein include those available commercially under the
tradename CARBOWAX polyethylene gycols and methoxypolyethylene
glycols from Dow Chemical Company, such as CARBOWAX PEG 200, 300,
400, 600, 900, 100, 1450, 3350, 4000, or 8000, under the trademark
PURACOL polyethylene glycols from BASF Corporation, such as PURACOL
E 200, 300, 400, 600, 900, 1000, 1450, 3350, 4000, 6000, or 8000.
Non-limiting examples of polyalkylene glycol esters include mono-
or di-esters of various fatty acids, such as those available under
the tradename MAPEG polyethylene glycol esters from BASF
Corporation, such as MAPEG 200 mL or PEG 200 Monolaureate, MAPEG
400 DO or PEG 400 Dioleate, MAPEG 400 MO or PEG 400 Mono-oleate,
and MAPEG 500 DO or PEG 600 Dioleate. Non-limiting examples of
copolymers of ethylene oxide and propylene oxide include various
PLURONIC and PLURONIC R block copolymer surfactants such as those
available under the trademark DOWFAX non-ionic surfactants,
UNCON(RO) fluids and SYNALOX lubricants from DOW Chemical.
Non-limiting examples of polyoxyalkylene derivatives of a sorbitan
fatty acid ester include polyoxyethylene 20 sorbitan monolaurate
available under the tradename TWEEN 20 or T-MAZ 20, polyoxyethylene
4 sorbitan monolaurate available under the tradename TWEEN 21,
polyoxyethylene 20 sorbitan monopalmitate available under the
tradename TWEEN 40, polyoxyethylene 20 sorbitan monostearate
available under the tradenames TWEEN 60 and T-MAZ 60K,
polyoxyethylene 20 sorbitan mono-oleate available under the
tradename TWEEN 80 or T-MAZ 80, polyoxyethylene 20 tristearate
available under the tradename TWEEN 65 or T-MAZ 65K,
polyoxyethylene 5 sorbitan mono-oleate available under the
tradename TWEEN 81 or T-MAZ 81, polyoxyethylene 20 sorbitan
trioleate available under the tradename TWEEN 85 or T-MAZ 85K, and
the like.
[0040] The heat transfer fluid can further comprise colloidal
silica. Colloidal silica for use herein is of an average particle
size of about 1 nanometer (nm) to about 200 nm, more specifically
from about 1 nm to about 100 nm, and even more specifically from
about 1 nm to about 40 nm. The colloidal silica is advantageous as
a secondary corrosion inhibitor, and can sometimes improve the heat
transfer properties of the heat transfer fluid. While not wishing
to be bound by theory, it is believed that the use of silica of a
particular average particle size provides improvements in heat
transfer efficiency and/or heat capacity by providing a large
surface area for contact with the liquid coolant.
[0041] Non-limiting examples of colloidal silica include LUDOX from
DuPont or Grace Davidson, NYACOL or BINDZIL from Akzo Nobel or Eka
Chemicals, SNOWTEX from Nissan Chemical. Other suppliers of
suitable colloidal silica include Nalco and the like.
[0042] The colloidal silica can be present in the heat transfer
fluid in an amount of 0.01 to about 10,000 ppm, more specifically
of about 0.02 to about 2000 ppm, and even more specifically about
0.1 to about 1000 ppm, based on the total weight of the heat
transfer fluid.
[0043] Other additional corrosion inhibitors include cyclohexanoic
carboxylates derived from long chain fatty acids, as well as salts
and esters thereof, and amine compounds, such as mono-, di-, and
triethanolamine, morpholine, benzylamine, cyclohexylamine,
dicyclohexylamine, hexylamine, 2-amino-2-methyl-1-propanol,
diethylethanolamine, diethylhydroxylamine, 2-dimethylaminoethanol,
dimethylamino-2-propanol, and 3-methoxypropylamine. These
additional corrosion inhibitors can be added to the heat transfer
fluid, with the proviso that they do not produce adverse effects.
The other additional corrosion inhibitors can be present in the
heat transfer fluid in an amount of 0.01 wt % to about 5 wt %,
based on the total weight of the heat transfer fluid.
[0044] In certain embodiments, it can be advantageous if the heat
transfer fluid comprises a tetraalkylorthosilicate ester. The
tetraalkylorthosilicate ester comprises a C1-C20 alkyl group,
non-limiting examples of which include tetramethylorthosilicate,
tetraethylorthosilicate, and the like. The tetraalkylorthosilicate
ester can be present in the heat transfer fluid in an amount of
0.01 wt % to about 5 wt %, based on the total weight of the heat
transfer fluid.
[0045] The corrosion inhibiting heat transfer fluid can further
comprise a non-conductive colorant that is a non-ionic or a weakly
ionic species soluble or dispersible in the liquid coolant at the
concentration of the colorant required to provide coloring of the
heat transfer fluid.
[0046] In one embodiment, the non-conductive colorant is
substantially free of functional groups that will form an ionic
species due to hydrolysis in an aqueous alcohol or alkylene glycol
solution. In another embodiment, the non-conductive 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. Non-limiting examples of
groups that carry a positive charge include Na+, Cu2+, --NR33+
where R3 is H, C1-C20 alkyl groups or aromatic ring containing
groups, Fe3+, the like, and combinations thereof. Non-limiting
examples of groups that carry a negative charge include Cl-, Br-,
I-, and the like, and combinations thereof.
[0047] Non-limiting examples of non-conductive colorants include a
chromophore such as anthraquinone, triphenylmethane,
diphenylmethane, azo containing compounds, diazo containing
compounds, triazo containing compounds, xanthene, acridine, indene,
phthalocyanine, azaannulene, nitroso, nitro, diarylmethane,
triarylmethane, methine, indamine, azine, oxazine, thiazine,
quinoline, indigoid, indophenol, lactone, aminoketone,
hydroxyketone, stilbene, thiazole, a conjugated aromatic groups, a
conjugated heterocyclic group (e.g., stilbene,
bis-triazenylaminostilbene, pyrazoline, and/or coumarin type
molecule or a combination thereof), a conjugated carbon-carbon
double bond (e.g., carotene), and a combination thereof. In one
exemplary embodiment, the non-conductive colorants will comprise a
diarylmethane, triarylmethane, triphenylmethane, diphenylmethane, a
conjugated aromatic group, an azo group, or a combination thereof.
In an advantageous embodiment, the non-conductive colorant
comprises a chromophore comprising a conjugated aromatic group.
[0048] The non-conductive colorant can comprise alkyleneoxy or
alkoxy groups and a chromophore such as described above. In one
embodiment, the chromophore is selected from the group consisting
of anthraquinone, triphenylmethane, diphenylmethane, azo containing
compounds, diazo containing compounds, triazo containing compounds,
compounds comprising one or more conjugated aromatic groups, one or
more conjugated heterocyclic groups, and combinations thereof.
[0049] In one embodiment, non-conductive colorants can be of the
formula R4{Ak[(E)nR5]m}y wherein R4 is an organic chromophore
selected from the group consisting of anthraquinone,
triphenylmethane, diphenylmethane, azo containing compounds, diazo
containing compounds, triazo containing compounds, xanthene,
acridine, indene, thiazole, compounds comprising one or more
conjugated aromatic groups, one or more conjugated heterocyclic
groups, or combinations thereof, A is a linking moiety and is
selected from the group consisting of O, N or S, k is 0 or 1, E is
selected from the group consisting of one or more C1-C8 alkyleneoxy
or alkoxy groups, n is 1 to 100, m is 1 or 2, y is 1 to 5, and R5
is selected from the group consisting of H, C1-C6 alkyl or C1-C8
alkoxy groups, or combinations thereof.
[0050] In one exemplary embodiment, the non-conductive colorants
are of the formula R4{Ak[(E)nR5]m}y wherein R4 is as described
above, A is N or O, k is 0 or 1, E is a C2-C4 alkyleneoxy group, n
is from 1 to 30, m is 1 or 2, y is 1 or 2, and R5 is H, a C1-C4
alkyl group, or a C1-C6 alkoxy group.
[0051] The non-conductive colorants can be prepared by various
known methods such as those described in U.S. Pat. No. 4,284,729,
U.S. Pat. No. 6,528,564 or other patents issued to Milliken &
Company, Spartanburg, S.C., USA.
[0052] For example, suitable colorants can 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.
[0053] In the case of azo dyestuffs, this can 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.
[0054] 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.
[0055] Other suitable colorants can also be prepared by these and
other known procedures. Colorants containing contaminating ionic
species can be used if purification methods are employed.
Illustrative purification and chemical separation techniques
include treatment with ion exchange resins, reverse osmosis,
extraction, absorption, distillation, filtration, and the like, and
similar processes used to remove the ionic species and obtain a
purified colorant that is electrically non-conductive.
[0056] Non-limiting examples of commercially available
non-conductive colorants for use in the heat transfer fluid include
LIQUITINT Red ST or other similar polymeric colorants from Milliken
Chemical of Spartanburg, S.C., USA, or colorants from Chromatech of
Canton, Mich., USA. Illustrative examples include the following:
LIQUITINT Red ST, LIQUITINT Blue RE, LIQUITINT Red XC, LIQUITINT
Patent Blue, LIQUITINT Bright Yellow, LIQUITINT Bright Orange,
LIQUITINT Royal Blue, LIQUITINT Blue N-6, LIQUITINT Bright Blue,
LIQUITINT Supra Blue, LIQUITINT Blue HP, LIQUITINT Blue DB,
LIQUITINT Blue II, LIQUITINT Exp. Yellow 8614-6, LIQUITINT Yellow
BL, LIQUITINT Yellow II, LIQUITINT Sunbeam Yellow, LIQUITINT Supra
Yellow, LIQUITINT Green HMC, LIQUITINT violet, LIQUITINT Red BL,
LIQUITINT Red RL, LIQUITINT Cherry Red, LIQUITINT Red II, LIQUITINT
Teal, LIQUITINT Yellow LP, LIQUITINT Violet LS, LIQUITINT Crimson,
LIQUITINT Aquamarine, LIQUITINT Green HMC, LIQUITINT Red HN,
LIQUITINT Red ST, and combinations thereof.
[0057] In one exemplary embodiment, the non-conductive colorant is
selected from the group consisting of LIQUITINT Red ST from
Milliken, LIQUITINT Red XC from Chromatech, CHROMATINT Yellow 1382
from Chromatech and LIQUITINT Blue.RTM. RE from Chromatech, while
in an advantageous embodiment, the non-conductive colorant is
LIQUITINT Blue RE from Chromatech.
[0058] The non-conductive colorant can be present in the heat
transfer fluid in an amount of 0.0001 to 0.2 wt %, based on the
total weight of the heat transfer fluid. In another embodiment, the
non-conductive colorant can be present in the heat transfer fluid
in an amount of 0.0002 to 0.1 wt %, based on the total weight of
the heat transfer fluid, while in one exemplary embodiment, the
non-conductive colorant can be present in an amount of 0.0003 to
0.05 wt %, based on the total weight of the heat transfer
fluid.
[0059] The heat transfer fluids can also comprise additional
additives such as other colorants, wetting agents, other antifoam
agents, biocides, bitterants, nonionic dispersants or combinations
thereof in amounts of up to 10 wt %, based on the total weight of
the heat transfer fluid.
[0060] The conductivity of the heat transfer fluid can be measured
by using the test methods described in ASTM D1125, that is,
"Standard Test Methods for Electrical Conductivity and Resistivity
of Water" or an equivalent method. The conductivity of the heat
transfer fluid disclosed herein is less than about 100 .mu.S/cm. In
one embodiment, the conductivity is less than about 70 .mu.S/cm,
while in another embodiment, the conductivity is less than about 50
.mu.S/cm, and yet in another embodiment the conductivity is less
than about 25 .mu.S/cm.
[0061] In other embodiments, the heat transfer fluid can have an
electrical conductivity of about 0.02 to about 100 .mu.S/cm,
specifically about 0.02 to about 50 .mu.S/cm, more specifically
about 0.05 to about 25 .mu.S/cm, more specifically about 0.05 to
about 10 .mu.S/cm. In one advantageous embodiment, the heat
transfer fluid has an electrical conductivity of about 0.05 to
about 5 .mu.S/cm.
[0062] The heat transfer fluid can be prepared by mixing the
different components together and homogenizing the resulting
mixture. Generally, the alcohol and water are advantageously mixed
together first. The other components and additives are then added
to the alcohol-water mixture by mixing and adequate stirring. In
one embodiment, the alcohol is mixed with the other components
first, excluding the water. The resulting mixture is then
homogenized. Water can then be added prior to packaging and/or
prior to use of the heat transfer fluid.
[0063] The heat transfer fluid can be used in a variety of
assemblies. It is advantageous to use the heat transfer fluid in
assemblies comprising heat transfer systems which comprise aluminum
and/or magnesium, and wherein the heat transfer fluid, once
introduced into the heat transfer system, is in contact with the
aluminum and/or magnesium. It is also advantageous to use the heat
transfer fluid in assemblies where the heat transfer fluid is
exposed to an electrical current (such as in fuel cells, and the
like).
[0064] The assemblies comprise internal combustion engines or
alternative power sources, among others. Internal combustion
engines include those that are powered by gasoline, and also those
that are powered by natural gas, diesel, methanol, hydrogen, the
condensation of steam, and/or the like. Non-limiting examples of
alternative power sources include batteries, fuel cells, solar
cells, solar panels, photovoltaic cells. Alternative power sources
can include devices powered by internal combustion engines
operating with a clean heat transfer system, that is, a heat
transfer system that does not contribute to the concentration of
ionic species in the heat transfer fluid. Such alternative power
sources can be used alone or in combination, such as those employed
in hybrid vehicles.
[0065] Assemblies comprising such alternative power sources include
any assembly that can traditionally be powered by an internal
combustion engine, such as automotive vehicles, boats, generators,
lights, aircrafts, airplanes, trains, locomotives, military
transport vehicles, stationary engines, and the like. The
assemblies also include additional systems or devices required for
the proper utilization of power sources, such as electric motors,
DC/DC converters, DC/AC inverters, electric generators, and other
power electronic devices, and the like.
[0066] Other exemplary heat transfer systems wherein the heat
transfer fluid is exposed to an electrical current include those
that are used in glass and metal manufacturing processes where a
high electrical voltage/current is applied to the electrodes to
keep a material such as glass or steel in a molten state. Such
processes generally require a heat transfer fluid having low
conductivity to cool the electrodes.
[0067] The disclosed assemblies include a power source comprising a
heat transfer system in thermal communication with the alternative
power source and with the heat transfer fluid. In one embodiment,
the heat transfer system comprises a circulation loop defining a
flow path for the heat transfer fluid. The heat transfer system can
be integrated with the power source, that is, the power source can
be a part of the heat transfer system. In one embodiment, the heat
transfer system comprises a circulation loop defining a flow path
for the heat transfer fluid, the circulation loop flowing through
the power source.
[0068] Thus, in one embodiment, a heat transfer system comprises a
circulation loop defining a flow path for a heat transfer fluid,
and a heat transfer fluid comprising a liquid coolant, a siloxane
corrosion inhibitor, and a non-conductive polydiorganosiloxane
antifoam agent, wherein the conductivity of the heat transfer fluid
is less than about 100 .mu.S/cm, and wherein the heat transfer
system comprises aluminum, magnesium, or a combination thereof, in
intimate contact with the heat transfer fluid.
[0069] In an exemplary embodiment referred to in FIG. 1, the power
source is an internal combustion engine, and the heat transfer
system comprises magnesium. It will be understood that while FIG. 1
refers to an exemplary embodiment wherein the heat transfer system
comprises magnesium, it is not limited thereto and can also
comprise aluminum, or the like. A combination of the metals can
also be used.
[0070] Thus, referring now to FIG. 1, an exemplary heat transfer
system 10 comprises a heat transfer fluid reservoir 12, a pump 14,
an engine 16, a heater core 18, a thermostat 20, a radiator cap 22,
an overflow tank 26 and a radiator 24. The heat transfer system can
further comprise an ion exchange resin 28, conduits (e.g., pipe
30), valves (not shown) and other pumps. Each component of the heat
transfer system 10 can comprise magnesium. In one exemplary
embodiment, at least one of the components of the heat transfer
system 10 comprises magnesium and/or magnesium alloys. In another
exemplary embodiment, each of the pump 14, the engine 16, the
heater core 18, the thermostat 20, the radiator cap 22, the
overflow tank 26, and the radiator 24 comprises magnesium. In
another exemplary embodiment, one or more components comprise
magnesium while one or more other components comprise aluminum.
[0071] The reservoir 12 is provided to maintain the heat transfer
fluid in an environment free from undesirable contaminants when the
fluid is not circulating. In one embodiment, reservoir 12 comprises
plastic.
[0072] The pump 14 is provided to drive the fluid through the heat
transfer system 10. Specifically, pump 14 routes fluid from the
reservoir, through an engine block of the engine 16, that is,
through a first set of interior passages of the engine that are
disposed proximate the engine cylinder, through heater core 18,
through a second set of interior passages of the engine block, and
to the thermostat 20. Depending on the position of the thermostat
20, the fluid is then routed through either the radiator cap 22,
the radiator 24, then to the pump 14, or directly to the pump 14.
The pump 14 can be a centrifugal pump driven by a belt connected to
a crankshaft of the engine 16. The pump 14 pumps heat transfer
fluid through the heat transfer system 10 when the engine 16 is
operating. The pump 14 can comprise a rotating component comprising
an impeller and a shaft. The pump 14 can further comprise a
stationary component comprising a casing, a casing cover, and
bearings. In an exemplary embodiment both the rotating component of
the pump and the casing component of the pump comprise magnesium.
In another exemplary embodiment only the rotating component, the
casing component, or subcomponents of the rotating component and
casing component comprise magnesium.
[0073] The engine 16 comprises the engine block, cylinders,
cylinder connecting rods, and a crankshaft. The engine block
comprises internal passageways disposed therethrough. The internal
passageway can be cast or machined in the engine block. The heat
transfer fluid can be routed through the internal passageways of
the engine to transfer heat from the engine. These passageways
direct the heat transfer so that the fluid can transfer heat away
from the engine to optimize engine performance.
[0074] In an exemplary embodiment the metal engine components
comprise magnesium. Specifically, the engine block, the cylinders,
the cylinder connecting rods, and the crankshaft comprise
magnesium. In an alternative exemplary embodiment, certain engine
components can comprise magnesium, while other engine components do
not comprise magnesium. For example, the engine block can comprise
magnesium, while the cylinder, cylinder connecting rods, and the
crankshaft can comprise steel.
[0075] The heater core 18 is provided to cool the heat transfer
fluid while heating a vehicle interior. The heater core 18 can
comprise a series of thin flattened tubes having a high interior
surface area and exterior surface area such that heat can be
effectively transferred away from the heat transfer fluid. In an
exemplary embodiment, the heating core 18 comprises magnesium tubes
brazed together. In another exemplary embodiment the heating core
can comprise tubes joined together by other joining methods or the
heating core can be cast as a single unit. Air can be forced past
the heater core to increase the cooling rate of the heat transfer
fluid.
[0076] The thermostat 20 is provided to measure a temperature
indicative of a selected heat transfer fluid temperature and
selectively routes the heat transfer fluid to the radiator or to
the pump. Thermostat 20 routes the heat transfer fluid to the
radiator when the temperature of the heat transfer fluid is greater
than or equal to the selected temperature and to the pump when the
temperature of the heat transfer fluid is less than the selected
temperature. The thermostat has an inlet portion, a radiator outlet
portion, a radiator bypass outlet portion, and a valve portion. A
single housing member can define the inlet portion, the radiator
outlet portion, and the radiator bypass outlet portion. The valve
portion can be disposed within the single housing member and
provide selective communication between the inlet portion and both
the radiator outlet portion and the radiator bypass outlet portion.
When the valve is in a closed position, the thermostat routes the
heat transfer fluid directly to the pump. When the valve is in the
open position, the thermostat routes the heat transfer fluid
through the radiator. In an exemplary embodiment, the thermostat
valve portion and the thermostat housing member comprise magnesium.
In another exemplary embodiment, only the housing or only the valve
portion comprise magnesium.
[0077] The radiator cap 22 is provided to seal the heat transfer
system and to maintain the heat transfer fluid at a selected
pressure to prevent the heat transfer fluid from boiling. In an
exemplary embodiment, the radiator cap 22 comprises magnesium.
[0078] The radiator 24 is provided to cool the heat transfer fluid.
The radiator 24 can comprise a series of thin flattened tubes
having a high interior surface area and exterior surface area such
that heat can be effectively transferred from the heat transfer
fluid. In an exemplary embodiment, the radiator 24 comprises
magnesium tubes brazed together. In another exemplary embodiment
the radiator can comprise tubes joined together by other joining
methods or case as a single unit. Air can be forced past the
radiator to increasing the cooling rate of the heat transfer
fluid.
[0079] The optional ion exchange resin (not shown) exchanges ions
with the heat transfer fluid. Specifically, the ion exchange resin
removes corrosive ions from the heat transfer fluid and replaces
the corrosive ions with ions that reduce the caustic properties of
the heat transfer fluid. The ion exchange resin is in fluid
communication with the heat transfer fluid, and with the flow path
and/or circulation loop defined by the heat transfer system. In one
embodiment, the heat transfer system 10 comprises an ion exchange
resin. In one embodiment, the ion exchange resin is disposed
between the engine and the thermostat.
[0080] In another embodiment, the ion exchange resin is disposed in
other locations of the heat transfer system 10. For example, the
ion exchange resin is disposed between other heat transfer system
components. Further, the ion exchange resin can be disposed within
the heat transfer system components, such as in the heat transfer
fluid reservoir.
[0081] Non-limiting examples of ion exchange resins include anion
exchange resins, cation exchange resins, mixed bed ion exchange
resins, and combinations thereof. The ion exchange resin comprises
a polymer matrix comprising polymers comprising functional groups
paired with an exchangeable ion. The exchangeable ion is generally
one or more of Na+, H+, OH-, or Cl- ions, depending on the type of
ion exchange resin.
[0082] Non-limiting examples of polymers comprised in the polymer
matrix include polystyrene, polystyrene and styrene copolymers,
polyacrylates, aromatic substituted vinyl copolymers,
polymethacrylates, phenol-formaldehyde, polyalkylamine, and the
like, and combinations thereof. In one embodiment, the polymer
matrix comprises polystyrene and styrene copolymers, polyacrylates,
or polymethacrylates, while in one exemplary embodiment, the
polymer matrix comprises styrenedivinylbenzene copolymers.
[0083] Non-limiting examples of functional groups in cation ion
exchange resins include sulfonic acid groups (--SO3H), phosphonic
acid groups (--PO3H), phosphinic acid groups (--PO2H), carboxylic
acid groups (--COOH or --C(CH3)-COOH), and the like, and
combinations thereof. In one embodiment, the functional groups in
the cation exchange resin are --SO3H, --PO3H, or --COOH, while in
one exemplary embodiment, the functional groups in the cation
exchange resin are --SO3H.
[0084] Non-limiting examples of functional groups in anion exchange
resins include quaternary ammonium groups such as
benzyltrimethylammonium groups, termed type 1 resins,
benzyldimethylethanolammonium groups, termed type 2 resins,
trialkylbenzyl ammonium groups, also termed type 1 resins, tertiary
amine functional groups, and the like. In one embodiment, the
functional groups in the anion exchange resin are
benzyltrimethylammonium, or dimethyl-2-hydroxyethylbenzyl ammonium,
while in one exemplary embodiment the functional groups in the
anion exchange resin are benzyltrimethylammonium.
[0085] The particular ion exchange resin selected is dependent upon
the composition of the heat transfer fluid, and can exchange ions
with any ionic species produced by the heat transfer fluid. For
example, if the siloxane corrosion inhibitor, the non-conductive
polydimethylsiloxane antifoam agent, the azole, or any additive in
the heat transfer fluid are more likely to become negatively
charged, the ion exchange resin should be a mixed bed resin, an
anion exchange resin, or a combination thereof. Commercially
available anion exchange resins typically comprise OH- or Cl-
exchangeable ions. In one embodiment, the exchangeable ion is
OH-.
[0086] Alternatively, if the siloxane corrosion inhibitor, the
non-conductive polydimethylsiloxane antifoam agent, the azole, or
any additive in the heat transfer fluid are likely to become
positively charged, then mixed bed resins, cation exchange resins
or a combination thereof should be used. Commercially available
cation exchange resins typically comprise H+ or Na+ exchangeable
ions. In one embodiment, the exchangeable ion is H+.
[0087] Commercially available ion exchange resins suitable for use
herein are available from Rohm & Haas of Philadelphia, Pa. as
AMBERLITE, AMBERJET, DUOLITE, and IMAC resins, from Bayer of
Leverkusen, Germany as LEWATIT resin, from Dow Chemical of Midland,
Mich. as DOWEX resin, from Mitsubishi Chemical of Tokyo, Japan as
DIAION and RELITE resins, from Purolite of Bala Cynwyd, Pa. as
PUROLITE resin, from Sybron of Birmingham, N.J. as IONAC resin,
from Resintech of West Berlin, N.J., and the like. In one
embodiment, the suitable commercially available ion exchange resin
is DOWEX MR-3 LC NG Mix mixed bed resin, DOWEX MR-450 UPW mixed bed
resin, IONEC NM-60 mixed bed resin, or AMBERLITE MB-150 mixed bed
resin, while in one exemplary embodiment, the suitable commercially
available ion exchange resin is DOWEX MR-3 LC NG Mix.
[0088] In one embodiment, the ion exchange resin is pre-treated
with a corrosion inhibiting composition prior to use in the heat
transfer system. The ion exchange resin is pre-treated by
contacting the ion exchange resins with an aqueous corrosion
inhibiting solution comprising the corrosion inhibiting composition
for a selected time period. In one embodiment, the ion exchange
resin is contacted with the aqueous corrosion inhibiting
composition solution for a period of time sufficient to allow the
corrosion inhibiting composition to exchange ions with at least
about 15% of the total exchangeable ions, based on the total number
of exchangeable ions in the ion exchange resin. That is, the
corrosion inhibiting composition loading of the corrosion
inhibiting composition treated ion exchange resin should be at
least about 15% of the exchange capacity of the ion exchange resin.
In another embodiment, the period of contact is sufficient to allow
the corrosion inhibiting compositions to exchange ions with at
least about 50% of the total exchangeable ions, 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 corrosion inhibiting composition to exchange ions with at least
about 75% of the total exchangeable ions, 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 corrosion inhibiting composition loading of the corrosion
inhibiting composition treated ion exchange resin to be an amount
of about 15 to about 99% of the total exchange capacity of the ion
exchange resin or from about 15 to about 99% of the total
exchangeable ions, based on the total number of exchangeable ions
in the ion exchange resin.
[0089] In one exemplary embodiment, the resultant corrosion
inhibiting composition treated ion exchange resins will be cleansed
with de-ionized water and/or the heat transfer fluid to minimize
the chance for accidental introduction of impurities.
[0090] In one embodiment, ion exchange resins in Na+ or Cl- forms
are used only if the treatment with the aqueous corrosion
inhibiting solution results in the removal of substantially all of
the Na+ or Cl- ions from the ion exchange resin. In one embodiment,
ion exchange resins in Na+ or Cl- forms are used if the treatment
with the aqueous corrosion inhibiting solution results in the
corrosion inhibiting composition loading of the corrosion
inhibiting composition treated ion exchange resin being at least
about 80% of the total exchangeable ions.
[0091] The corrosion inhibiting compositions for treating the ion
exchange resin comprises a siloxane corrosion inhibitor, an azole,
or a combination thereof. Suitable siloxane corrosion inhibitors
and azoles are those described above. The corrosion inhibiting
compositions are weakly ionic and therefore, when in contact with
the heat transfer fluid, maintain the low conductivity of the heat
transfer fluid.
[0092] The amount of corrosion inhibiting composition released from
the resin depends on the level of corrosive ions in the heat
transfer fluid. The corrosion inhibiting composition is
advantageous since an increase in the amount of corrosive ions in
the heat transfer fluid produces an increase in the amount of
corrosion inhibiting composition from the resin being released into
the heat transfer fluid due to the ion exchange mechanism. The
increase in the amount of corrosion inhibiting composition
concentration in the heat transfer fluid will lead to a reduction
in the corrosion rate. Another advantage of the heat transfer
system is that the presence of the ion exchange rein, and
advantageously, the mixed bed ion exchange resin, will also
maintain low conductivity in the heat transfer fluids in the
system.
[0093] In one embodiment, acidic aqueous corrosion inhibiting
solutions suitable for treating the ion exchange resin have a pKa
value of equal to or greater than about 5 at 25.degree. C.,
specifically from about 5 to about 14. In another embodiment, basic
aqueous corrosion inhibiting solutions suitable for treating the
ion exchange resin have a pKb value of equal to or greater than
about 5 at 25.degree. C., specifically from about 5 to about
14.
[0094] Further, the ion exchange resin can be treated with other
additives such as colorants, wetting agents, antifoam agents,
biocides, and nonionic dispersants, with the proviso that the other
additives do not substantially increase the overall electrical
conductivity of the heat transfer fluid when the additives are
added to the heat transfer fluid.
[0095] In one embodiment, the ion exchange resin will be treated
with a non-conductive polydimethylsiloxane emulsion based antifoam.
Suitable polydimethylsiloxane emulsion based antifoams include
those described above.
[0096] In another exemplary embodiment referred to in FIG. 2, an
assembly comprises a power source that can be an internal
combustion engine, or advantageously, an alternative power source,
specifically a solar cell or fuel cell. The heat transfer system
comprises magnesium. The assembly can also comprise a regenerative
braking system. It will be understood that while FIG. 2 refers to
an exemplary embodiment wherein the heat transfer system comprises
magnesium or aluminum, any other susceptible metal can be used
therein.
[0097] Thus, referring now to FIG. 2, an exemplary heat transfer
system 116 comprises an internal combustion engine 105, or fuel
cells 105 or solar cells 105 as the primary power source 107. It
also comprises a rechargeable secondary battery 112 or an optional
ultra-capacitor 113 that can be charged via the assembly's
regenerative braking system. The battery 112 and/or the
ultra-capacitor 113 can act as secondary power sources. The
assembly can further comprise power electronic devices, such as
DC/DC converters 110, DC/AC inverters 110, generators 108, power
splitting devices 109, and/or voltage boost converters 111, and the
like. In addition, the assembly can contain fuel cell or solar cell
"balance of plant" subsystems 106. These can be air compressors,
pumps, power regulators, and the like. The assembly also comprises
HAVC systems 114, such as, air-conditioning system for the climate
control of assembly interior space. The heat transfer system 116
further comprises a pump 101, heat transfer fluid flow path 104,
heat transfer fluid tank 102, and a radiator or heat exchanger 103,
and a fan 115. The fan can be substituted by an external cooling
source, such as a different (or isolated) cooling system with its
own cooling media. An ion exchange resin (not shown) can also be
present, and is as described above.
[0098] In one embodiment, the alternative power source is a fuel
cell. The fuel cell is in thermal communication with the heat
transfer systems and fluids. In one embodiment, the electrical
conductivity of the heat transfer fluids is less than about 10
.mu.S/cm. In an exemplary embodiment comprising a fuel cell, the
heat transfer fluid comprises an electrical conductivity of about
0.02 to about 10 .mu.S/cm. In one advantageous embodiment, the heat
transfer fluid comprises an electrical conductivity of about 0.05
to about 5 .mu.S/cm.
[0099] The heat transfer fluid can be used in 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 heat transfer fluid can be contained or flow in
channel or flow path defined by a circulation loop or heat transfer
fluid flow channel in thermal communication with the fuel cell.
[0100] Non-limiting examples of 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 heat transfer fluid is used
in PEM and AFC fuel cells.
[0101] The invention is further illustrated by the following
non-limiting examples.
Examples 1-14
[0102] Table 1 illustrates the composition of heat transfer fluids,
represented by Fn, with n being the number of the fluid.
TABLE-US-00001 TABLE 1 Fluid (Fn) Composition F1 50 wt %
conventional coolant comprising ionic corrosion inhibitors. The
concentrate of this coolant contains greater than 94 wt % ethylene
glycol, 0.1 to 0.3 wt % tolyltriazole, 0.2 to 0.5 wt % nitrate, up
to 0.1 wt % molybdate, 0.1 to 2.0 wt % borax, 0.1 to 0.5 wt %
phosphoric acid, 0.1 to 0.5 wt % of silicate, 0.4 to 2.0 wt % of
NaOH or KOH or their mixtures, very small amounts (e.g., less than
0.1 wt %) of antifoams and colorants. F2 50 wt % monoethylene
glycol, 0.116 wt % siloxane corrosion inhibitor (i.e., Silwet
L-7657 from GE Silicone; 116 ppm benzotriazole, 350 ppm
non-conductive polydimethylsiloxane antifoam agent (i.e., PC-5450
NF antifoam), the balance deionized water. F3 50 wt % monoethylene
glycol, the balance deionized water. F4 43 wt % mixture of ethylene
glycol and 1,2-propylene glycol (~80 wt % of the mixture is
ethylene glycol and the remaining ~20 wt % is 1,2-propylene
glycol), 400 ppm siloxane corrosion inhibitor, or Silwet L-7657,
100 ppm benzotriazole, 800 ppm non-conductive polydimethylsiloxane
antifoam agent, or PC-5450 NF antifoam, the balance deionized
water. F5 50 wt % monoethylene glycol, 400 ppm siloxane based
corrosion inhibitor Silwet L-7657; 100 ppm benzotriazole, 800 ppm
non-conductive polydimethylsiloxane antifoam agent PC-5450 NF, the
balance deionized water. F6 50 wt % monoethylene glycol, 400 ppm
siloxane corrosion inhibitor Silwet L-7657, 100 ppm benzotriazole,
800 ppm non-conductive polydimethylsiloxane antifoam agent, i.e.,
PC-5450 NF, 100 ppm sorbitan fatty acid esters, i.e., Span 20,
available from Aldrich, 100 ppm polyethylene glycol corrosion
inhibiting surfactant, i.e., Carbowax 400, available from from Dow
Chemicals, the balance deionized water. F7 50 volume % (vol %)
Valvoline ZEREX G-05 (hybrid) coolant, the balance deionized water.
Valvoline Zerex G-05 coolant concentrate contains greater than 94
wt % ethylene glycol, 0.1 to 0.4 wt % nitrate, 0.1 to 0.4 wt %
nitrite, 0.5 to 2.5 wt % borax, 0.05 to 0.15 wt % benzotriazole,
0.1 to 0.2 wt % silicate, 1 to 3 wt % benzole acid, 0.4 to 2.0 wt %
NaOH or KOH or their mixture, and very small amounts (e.g., less
than 0.1 wt %) of antifoams and colorants and up to 0.5 wt % of a
polymer dispersant. F8 50 vol % Toyota LONG LIFE red coolant, the
balance deionized water. The coolant concentrate contains greater
than 94 wt % ethylene glycol, 3 to 5 wt % benzole acid, 0.1 to 0.3
wt % benzotriazole, 0.1 to 0.4 wt % mecaptobenzothiazole, 0.5 to 1
wt % phosphoric acid, 0.5 to 1 wt % molybdate, 0.1 to 0.5 wt %
nitrate, 0.5-5 wt % NaOH or KOH or their mixtures, and very small
amounts (e.g., less than 0.1 wt %) of antifoams and colorants, as
well as very small amount of other coolant additives such as a
phosphonate scale inhibitor and hardness ions. F9 50 volume %
Texaco HD coolant, the balance deionized water. The coolant
concentrate contains greater than 94 wt % ethylene glycol, 2 to 4
wt % ethyl hexanoic acid, 0.1 to 0.4 wt % sebacic acid, 0.2 to 0.5
wt % tolytriazole, 0.1 to 0.4 wt % sodium nitrite, 0.2 to 1 wt %
molybdate, 0.5 to 5 wt % of KOH or NaOH or their mixtures, and very
small amounts (e.g., less than 0.1 wt %) of antifoams, and
colorants. F10 50 wt % monoethylene glycol, 400 ppm siloxane based
surfactant (i.e., Silwet L-7657), 100 ppm benzotriazole, 800 ppm
polydimethylsiloxane emulsion based antifoam (i.e., PC-5450 NF),
200 ppm sorbitan fatty acid esters (i.e., Span-20), and 200 ppm
polyethylene glycol corrosion inhibiting surfactant (i.e., Carbowax
400).
[0103] Table 2 illustrates the corrosion results obtained in a
galvanic couple where a MRI202S magnesium alloy anode is
galvanically coupled to a copper cathode. A 0.5 square centimeter
magnesium alloy coupon is placed in a heat transfer fluid along
with a 1.1 square centimeter copper alloy coupon. The coupons are
placed 1 centimeter apart and the temperature is maintained at
88.degree. C. Conductivity, average corrosion rate, and corrosion
loss level results of the magnesium alloys in solution are listed
below. In each example magnesium corrosion loss was measured over a
total time of 12,000 seconds. En refers to Example, wherein n is
the number of the example.
[0104] The test solutions used are described in Table 1. In the
galvanic couple experiment, the galvanic couple current density is
measured as a function of time. In general, the current density is
varied over time. The total charge in Table 2 represents the total
amount of the galvanic corrosion occurring during a test. Average
corrosion rate and corrosion loss data are calculated by using the
total charge and total time of the test according to the Faraday
law and expected corrosion anodic reaction, i.e.,
Mg.fwdarw.Mg2++2e-.
[0105] Final galvanic couple current density represents the instant
galvanic corrosion rate of the magnesium alloy at the end of the
test. In general, if the average corrosion rate and the corrosion
loss value is lower for a given inhibitive coolant formulation, it
indicates that the coolant formulation is providing a better
corrosion protection than a coolant formulation that yields a
higher corrosion rate.
[0106] In Examples 3-8 an ion exchange resin is also placed in the
solution. Resin 1 comprises 3 grams of DOWEX MR-450 UPW. Resin 2
comprises 3.5 grams of Amberjet UP6040 ion exchange resin, treated
with an aqueous benzotriazole solution. Resin 3 comprises 7.0 grams
of DOWEX MR-450 UPW and 1.75 grams of untreated Amberjet UP6040.
Resin 4 comprises 7.0 grams of DOWEX MR-450 UPW treated with an
aqueous benzotriazole solution. Resin 5 comprises 14.35 grams of
Dowex MR-450 UPW treated with an aqueous benzotriazole solution and
3.5 grams of untreated DOWEX MR-450 UPW. The dry resin is the resin
refers to the resin as received from the supplier. The wet resin
refers to the resin treated with an aqueous benzotriazole solution.
The resin after treatment was recovered from the treatment
container, i.e., a pyrex beaker, using a stainless steel spatula.
The resin was then transferred to a clean and inert ion exchange
resin filter bag made of Nylon. The excess amount of water was
drained by the force of gravity. After the excess amount of water
was removed from the treated resin, the resin was stored in a clean
glass bottle for later use. The benzotriazole pretreatment of the
resin was typically conducted by adding 10 g of Dowex MR-450 UPW
mixed bed ion exchange resin into 1 liter of deionized water.
Before adding the ion exchange resin, 1200 mg/L benzotriazole was
dissolved in the 1 liter of the deionized water. Under constant
magnetic stirring via the use of a Teflon coated magnet stirring
bar and a magnetic stirrer, the resin and the benzotriazole aqueous
solution were allowed to react for 22 hours at room temperature.
During this treatment process, benzotriazole is exchanged with H+
and OH- groups in the mixed bed ion exchange resin so that the
resin is saturated with benzotriazole at all the exchangeable
sites. The mixed bed ion exchange resin obtained after the
treatment is termed the benzotriazole treated resin.
TABLE-US-00002 TABLE 2 Example (En) E1 E2 E3 E4 E5 E6 E7 E8 Fluid
(Fn) F1 F2 F2 F2 F2 F3 F4 F5 Ion Exchange Resin None None Resin 1
Resin 2 Resin 3 Resin 1 Resin 4 Resin 5 Total Charge (mC/cm.sup.2)
3704 237.6 16.44 56.86 18.72 14.87 72.45 24.73 Final Current
Density at 210.8 25.51 1.226 4.238 1.432 1.073 5.827 1.884 the end
of the galvanic couple test (.mu.A/cm.sup.2) Average corrosion Rate
19.322 1.239 0.086 0.291 0.098 0.078 0.378 0.129 (.mu.m/day)
Corrosion Loss 23.508 1.508 0.104 0.355 0.119 0.094 0.460 0.157
(mg/week/cm.sup.2) Conductivity N.D. 1.09/4.97 1.16/0.16 0.78/N.D.
0.14/0.15 0.29/0.19 0.29/0.41 0.98/0.17 Initial/Final (.mu.S/cm)
Final BZT (ppm) N.D. N.D. 0 N.D. 12 0 157 27 N.D. = not
detectable
[0107] Table 3 illustrates the test results obtained in galvanic
couple corrosion experiments where a MRI202S magnesium alloy anode
is galvanically coupled to a mild steel C1018 cathode. A 0.5 square
centimeter magnesium alloy coupon is placed in a heat transfer
fluid along with a 1.1 square centimeter steel coupon. The coupons
are placed 1 centimeter apart and the temperature is maintained at
88.degree. C. Conductivity, average corrosion rate, and corrosion
loss level results of the magnesium alloys in solution are listed
below. In each example magnesium corrosion loss was measured over a
total time of 12,000 seconds.
[0108] In Examples 9 and 14 an ion exchange resin is also placed in
the solution. Resin 6 comprises 10 grams of MR-450 UPW treated with
an aqueous benzotriazole solution and 3 grams of MR-450UPW. Resin 7
comprises 10 grams of MR-450 UPW treated with an aqueous
benzotriazole solution and 3.7 grams of MR-450UPW.
TABLE-US-00003 TABLE 3 Example (En) E9 E10 E11 E12 E13 E14 Fluid
(Fn) F6 F7 F8 F1 F9 F10 Ion Exchange Resin Resin 6 None None None
None Resin 7 Total Charge (mC/cm.sup.2) 40.3 41210 513.1 58.34
13280 19.26 Current Density (.mu.A/cm.sup.2) 3.32 2640 35.84 3.657
982.1 1.33 Total Time (sec) 1200 1200 11333 1200 1200 1200 Av corr
Rate (.mu.m/day) 0.210 214.977 2.834 0.304 69.277 0.100 Corr Loss
(mg/week/cm.sup.2) 0.256 261.542 3.448 0.370 84.284 0.122
Conductivity 1.03/0.20 6770/6110 10550/9230 3510/2890 6970/6020
1.05/0.14 Initial/Final (.mu.S/cm) Final BZT (ppm) 39 N.D. N.D.
N.D. N.D. N.D.
[0109] As can be seen from Tables 2 and 3, the heat transfer fluids
lacking the siloxane corrosion inhibitor and non-conductive
polydimethylsiloxane antifoam agent has an average corrosion loss
rate of greater than 0.3 and up to as high as about 215 .mu.m/day
for E10. The examples with a siloxane corrosion inhibitor, an azole
and a non-conductive polydimethylsiloxane antifoam agent have a
magnesium average corrosion loss rates of less than 2.1 .mu.m/day.
It can also be seen that the benzotriazole-treated ion exchange
resins can be used to keep the conductivity similar to when
untreated ion exchange resins are used, and the same time allow the
presence of benzotriazole residual concentration in the heat
transfer fluid to provide the desirable corrosion protection for
copper based alloys and other metals in the heat transfer
system.
Example 15-26
[0110] Tables 5 and 6 illustrate the test results obtained in
galvanic couple corrosion tests where galvanic couples C1-C5 of
Table 4 were used. These galvanic couples are exemplary
magnesium-based compositions for use in automotive magnesium-based
heat transfer systems, among others. The mass loss was determined
according to a modified ASTM-D1384 procedure. The ASTM-D1384 test
was modified by using different arrangement of metal coupons as
described in Table 4.
TABLE-US-00004 TABLE 4 C1 Mg AS-21x (coupled to Brass via an AI
6061 spacer) C2 Mg AS-21x (coupled to SAE329 cast AI via an AI 6061
spacer) C3 Cast Aluminum SAE329 (coupled to Mg via AI 6061 spacer)
C4 Aluminum 3003 C5 Mg AS-21x
TABLE-US-00005 TABLE 5 Example (En) E15 E16 E17 E18 E19 E20 Couple
used (Cn) C1 C2 C3 C4 C5 C6 Mass Loss 2.5 34.1 22.2 -1.7* 0.8 16.8
(mg/cm.sup.2/week) Total Mass Loss 0.046 0.573 0.373 -0.029* 0.015
0.282 (mg/sample) Heat Transfer Fluid 60 wt % monoethylene glycol,
250 mg/L benzotriazole, and 0.1 wt % anthranilamide. *Indicates a
mass gain
TABLE-US-00006 TABLE 6 Example (En) E21 E22 E23 E24 E25 E26
Composition (Cn) C1 C2 C3 C4 C5 C6 Mass Loss 0.6 19.1 19.0 -0.6*
0.5 8.6 (mg/cm.sup.2/week) Total Mass Loss 0.011 0.321 0.319
-0.010* 0.009 0.144 (mg/sample) Heat Transfer Fluid 60 wt %
monoethylene glycol, 400 mg/L SILWET L-7657, 800 mg/L
non-conductive polydimethylsiloxane antifoam agent, 100 mg/L
benzotriazole. *Indicates a mass gain
[0111] As can be seen from Tables 5 and 6, the metals galvanically
coupled through heat transfer fluids that comprise a siloxane
corrosion inhibitor, and a non-conductive polydimethylsiloxane
antifoam agent (Table 6) exhibit substantially less weight loss due
to corrosion than metals galvanically coupled through heat transfer
fluids which lack the siloxane corrosion inhibitor, and a
non-conductive polydimethylsiloxane antifoam agent (Table 5).
Example 27-34
[0112] The following examples illustrate the ability of the ion
exchange resins to reduce the conductivity of a heat transfer
fluid.
[0113] Table 7 illustrates the results for Examples 27 and 28.10 g
of the resin was first immersed in 1000 g of a 50 wt % ethylene
glycol aqueous solution comprising 1200 ppm benzotriazole, and
stirred for 22 hours. 1 g of the resulting pretreated resin was
then immersed in 100 g of a 50:50 ethyleneglycol:deionized water
solution comprising 30 ppm sodium formate and 30 ppm sodium acetate
and stirred. Example 27 comprises a UP6040 resin and Example 28
comprises a DOWEX MR-3 LC NG Mix resin.
TABLE-US-00007 TABLE 7 Conductivity (.mu.S/cm) Time (min) E27 E28 0
25.8 25.9 20 16.18 16.98 40 9.13 10.76 60 5.87 7.33 103 2.21 3.22
150 0.72 1.17 200 0.45 0.57 235 0.39 0.47
[0114] Table 8 illustrates the results for Example 29. 9.7 g of the
resin was first immersed in 1000 g of a 50 wt % ethylene glycol
aqueous solution comprising 1300 ppm tolyltriazole, and stirred for
22 hours. 1 g of the resulting pretreated resin was then immersed
in 100 g of a 50:50 ethyleneglycol:deionized water solution
comprising 30 ppm sodium formate and 30 ppm sodium acetate and
stirred. Example 29 comprises a DOWEX MR-3 LC NG Mix Resin.
TABLE-US-00008 TABLE 8 Conductivity (.mu.S/cm) Time (min) E29 0
28.3 20 18.32 40 12.39 60 7.59 90 5.31 120 3.11 150 1.87 220 0.85
240 0.55
[0115] Table 9 illustrates the results for Examples 30-32. Example
30 was a blank resin conductivity test. In Example 29, 10 g of
MTO-DOWEX MR-3 LC NG Mix resin were pretreated by immersing in 250
g of a 50 wt % ethylene glycol aqueous solution comprising 1200 ppm
benzotriazole. In Example 30, 10 g of MTO-DOWEX MR-3 LC NG Mix
resin were pretreated by immersing in 500 g of a 50 wt % ethylene
glycol aqueous solution comprising 1200 ppm benzotriazole. 1 g of
the treated resin was immersed in 100 g of a 50 wt % ethylene
glycol solution comprising 30 ppm NaCl and stirred.
TABLE-US-00009 TABLE 9 E30 E31 E32 Time Conductivity Time
Conductivity Time Conductivity (min) (.mu.S/cm) (min) (.mu.S/cm)
(min) (.mu.S/cm) 0 36.9 0 37.3 0 38.2 20 25.9 20 22.2 20 26.6 40
15.37 45 9.18 40 16.6 60 8.99 56 6.57 65 7.77 80 4.84 75 3.15 85
5.09 105 2.19 130 0.61 105 2.81 127 1.09 181 0.15 120 2 180 0.18
200 0.11 140 1.3 240 0.08 240 0.08 190 0.38 240 0.16
[0116] Table 10 illustrates the results for Examples 33-35. For
Example 33, 10 g of MTO-DOWEX MR-3 LC NG Mix resin were pretreated
by immersing in 750 g of a 50 wt % ethylene glycol aqueous solution
comprising 1200 ppm benzotriazole. For Example 234, 10 g of
MTO-DOWEX MR-3 LC NG Mix resin were pretreated by immersing in 1000
g of a 50 wt % ethylene glycol aqueous solution comprising 1200 ppm
benzotriazole. For Example 35, 10 g of MTO-DOWEX MR-3 LC NG Mix
resin were pretreated by immersing in 1000 g of a 50 wt % ethylene
glycol aqueous solution comprising 1300 ppm tolyltriazole. 1 g of
the treated resin was immersed in 100 g of a 50 wt % ethylene
glycol solution comprising 30 ppm NaCl and stirred.
TABLE-US-00010 TABLE 10 E33 E34 E35 Conductivity Time Conductivity
Time Conductivity Time (min) (.mu.S/cm) (min) (.mu.S/cm) (min)
(.mu.S/cm) 0 35.8 0 39.4 0 38.7 20 20.0 25 17.09 20 25.1 40 12.42
45 11.1 40 18.16 60 8.77 80 4.39 60 10.89 103 2.95 105 2.21 90 6.80
150 0.68 130 1.24 120 3.10 200 0.25 160 0.59 150 1.53 235 0.20 185
0.4 220 0.55 215 0.33 240 0.34 236 0.31 Residual 14 ppm 102 ppm 130
ppm benzotriazole
[0117] It can be seen from the data in Tables 7-10 that
benzotriazole and tolyltriazole treated resins are effective at
removing undesirable ionic impurities such as Na+, Cl-, formate,
and acetate and thus reducing the conductivity of the thermal
exchange fluid while keeping the conductivity at a low level. The
benzotriazole or tolyltriazole treated ion exchange resin can also
leave a desirable residual amount of the triazole in the heat
transfer fluid as can be seen in Examples 33-35, and thus
maintaining effective corrosion protection for metals in the heat
transfer system.
[0118] This written description uses examples and figures to
disclose the invention, including the best mode, and also to enable
any person skilled in the art to make and use the invention. The
patentable scope of the invention is defined by the claims, and can
include other examples that occur to those skilled in the art. Such
other examples are intended to be within the scope of the claims if
they have structural elements that do not differ from the literal
language of the claims, or if they include equivalent structural
elements with insubstantial differences from the literal language
of the claims.
[0119] All cited patents, patent applications, and other references
are incorporated herein by reference in their entirety unless
otherwise indicated. However, if a term in the present application
contradicts or conflicts with a term in the incorporated reference,
the term from the present application takes precedence over the
conflicting term from the incorporated reference.
[0120] All ranges disclosed herein are inclusive of the endpoints,
and the endpoints are independently combinable with each other.
Further, disclosing a range is specifically disclosing all ranges
formed from any pair of any upper range limit and any lower range
limit within this range, regardless of whether ranges are
separately disclosed. It is not intended that the scope of the
invention be limited to the specific values recited when defining a
range.
[0121] The use of the terms "a", "an", "the", and similar referents
in the context of describing the invention (especially in the
context of the following claims) are to be construed to cover both
the singular and the plural, unless otherwise indicated herein or
clearly contradicted by context. Further, it should be noted that
the terms "first," "second," and the like herein do not denote any
order, quantity, or importance, but rather are used to distinguish
one element from another.
[0122] 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., it includes the degree of error associated with
measurement of the particular quantity).
[0123] Certain compounds are described herein using a general
formula that includes variables such as, but not limited to, R1,
R2, R3, X, Y, and the like. Unless otherwise specified, each
variable within such a formula is defined independently of other
variables.
[0124] The term "substituted" as used herein means that any one or
more hydrogen atoms on the designated atom or group is replaced
with a selection from the indicated group, provided that the
designated atom's normal valence is not exceeded.
[0125] As used herein, the term "alkyl" includes both branched and
straight chain saturated aliphatic hydrocarbon groups, having the
specified number of carbon atoms. The term C1-C7 alkyl as used
herein indicates an alkyl group having from 1 to about 7 carbon
atoms. When C0-Cp alkyl is used herein in conjunction with another
group, for example, heterocycloalkyl (C0-C2 alkyl), the indicated
group, in this case heterocycloalkyl, is either directly bound by a
single covalent bond (C0), or attached by an alkyl chain having the
specified number of carbon atoms, in this case from 1 to p carbon
atoms. Examples of alkyl include, but are not limited to, methyl,
ethyl, n-propyl, isopropyl, n-butyl, 3-methylbutyl, t-butyl,
n-pentyl, and sec-pentyl.
[0126] The term "non-conductive" as used herein relates to a
species that produces a conductivity increase of less than about 10
.mu.S/cm when introduced into a standard solution of deionized
water, at a maximum concentration of no more than 0.2% by weight,
based on the total weight of the standard solution.
[0127] "Substantially free of" as used herein refers to an amount
that is not in excess of an amount that will lead to the
conductivity of the heat transfer fluid to increase by more than 10
.mu.S/cm.
[0128] "Alternative power sources" as used herein refers to power
source technologies that provide improvements in energy efficiency,
environmental concerns, waste production, and management issues,
natural resource management, and the like.
[0129] "Metal" as used herein refers to the element metal, wherein
"metal alloy" or "metallic alloy" refers to the metal in
combination with one or more other metals. For example, magnesium
refers to the element magnesium, whereas a magnesium alloy refers
to a combination of magnesium with one or more other metals. Thus,
a magnesium alloy comprises magnesium, and a system comprising
magnesium can comprise either elemental magnesium alone, a
magnesium alloy, or a combination of elemental magnesium and a
magnesium alloy.
[0130] "High conductivity" as used herein refers to a conductivity
of greater than 100 .quadrature.S/cm.
* * * * *