Refrigeration process using azeotropic compositions of perfluoroethane and trifluoromethane

Compositions of perfluoroethane and trifluoromethane are disclosed as acceptable drop in replacements for R-503. Also disclosed are azeotropic or azeotrope-like compositions of admixtures of effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like composition. Such compositions are useful as cleaning agents, expansion agents for polyolefins and polyurethanes, refrigerants, aerosol propellants, heat transfer media, gaseous dielectrics, fire extinguishing agents, power cycle working fluids, polymerization media, particulate removal fluids, carrier fluids, buffing abrasive agents, and displacement drying agents.

FIELD OF THE INVENTION 
This invention relates to compositions, or mixtures, of fluorinated 
hydrocarbons and more specifically to azeotropic or azeotrope-like 
compositions comprising effective amounts of perfluoroethane and 
trifluoromethane, nitrous oxide, carbon dioxide, or fluoromethane to form 
an azeotropic or azeotrope-like composition. Such compositions are useful 
as cleaning agents, expansion agents for polyolefins and polyurethanes, 
refrigerants, aerosol propellants, heat transfer media, gaseous 
dielectrics, fire extinguishing agents, power cycle working fluids, 
polymerization media, particulate removal fluids, carrier fluids, buffing 
abrasive agents, and displacement drying agents. 
BACKGROUND OF THE INVENTION 
Fluorinated hydrocarbons have many uses, one of which is as a refrigerant. 
In refrigeration applications, a refrigerant is often lost during 
operation through leaks in shaft seals, hose connections, solder joints, 
and broken lines. In addition, the refrigerant may be released to the 
atmosphere during maintenance procedures on refrigeration equipment. 
Accordingly, it is desirable to use a single fluorinated hydrocarbon or an 
azeotropic or azeotrope-like composition that includes one or more 
fluorinated hydrocarbons as a refrigerant. Some nonazeotropic compositions 
that include one or more fluorinated hydrocarbons may also be used as 
refrigerants, but they have the disadvantage of changing composition, or 
fractionating, when a portion of the refrigerant charge is leaked or 
discharged to the atmosphere. If a non-azeotropic composition contains a 
flammable component, the blend could become flammable because of such a 
change in composition. Refrigerant equipment operation could also be 
adversely affected due to the change in composition and vapor pressure 
that results from fractionation. 
Fluorinated hydrocarbons may also be used as a cleaning agent or solvent to 
clean, for example, electronic circuit boards. Electronic components are 
soldered to circuit boards by coating the entire circuit side of the board 
with flux and thereafter passing the flux-coated board over preheaters and 
through molten solder. The flux cleans the conductive metal parts and 
promotes solder fusion, but leave residues on the circuit boards that must 
be removed with a cleaning agent. 
Preferably, cleaning agents should have a low boiling point, 
nonflammability, low toxicity, and high solvency power so that flux and 
flux-residues can be removed without damaging the substrate being cleaned. 
Further, it is desirable that cleaning agents that include a fluorinated 
hydrocarbon be azeotropic or azeotrope-like so that they do not tend to 
fractionate upon boiling or evaporation. If the cleaning agent were not 
azeotropic or azeotrope-like, the more volatile components of the cleaning 
agent would preferentially evaporate, and the cleaning agent could become 
flammable or could have less-desirable solvency properties, such as lower 
rosin flux solvency and lower inertness toward the electrical components 
being cleaned. The azeotropic property is also desirable in vapor 
degreasing operations because the cleaning agent is generally redistilled 
and reused for final rinse cleaning. 
Azeotropic or azeotrope-like compositions of fluorinated hydrocarbons are 
also useful as blowing agents in the manufacture of close-cell 
polyurethane, phenolic and thermoplastic foams. Insulating foams require 
blowing agents not only to foam the polymer, but more importantly to 
utilize the low vapor thermal conductivity of the blowing agents, which is 
an important characteristic for insulation value. 
Aerosol products employ both single component fluorinate hydrocarbons and 
azeotropic or azeotrope-like compositions of fluorinated hydrocarbons as 
propellant vapor pressure attenuators in aerosol systems. 
Azeotropic mixtures, with their constant compositions and vapor pressures 
are useful as solvents and propellants in aerosols. 
Azeotropic or azeotrope-like compositions that include fluorinated 
hydrocarbons are also useful as heat transfer media, gaseous dielectrics, 
fire extinguishing agents, power cycle working fluids such as for heat 
pumps, inert media for polymerization reactions, fluids for removing 
particulates from metal surfaces, and as carrier fluids that may be used, 
for example, to place a fine film of lubricant on metal parts. 
Azeotropic or azeotrope-like compositions that include fluorinated 
hydrocarbons are further useful as buffing abrasive detergents to remove 
buffing abrasive compounds from polished surfaces such as metal, as 
displacement drying agents for removing water such as from jewelry or 
metal parts, as resist-developers in conventional circuit manufacturing 
techniques employing chlorine-type developing agents, and as strippers for 
photoresists when used with, for example, a chlorohydrocarbon such as 
1,1,1-trichloroethane or trichloroethylene. 
Some of the fluorinated hydrocarbons that are currently used in these 
applications have been theoretically linked to depletion of the earth's 
ozone layer. What is needed, therefore, are substitutes for fluorinated 
hydrocarbons that have low ozone depletion potentials. 
SUMMARY OF THE INVENTION 
The present invention relates to the discovery that a mixture of 
perfluoroethane and trifluoromethane is a drop-in replacement refrigerant 
for R503, which is a mixture of trifluoromethane and 
chlorotrifluoromethane. The invention also relates to the discovery of 
azeotropic or azeotrope-like compositions comprising effective amounts of 
perfluoroethane and trifluoromethane, nitrous oxide, carbon dioxide, or 
fluoromethane to form an azeotropic or azeotrope-like composition. 
DETAILED DESCRIPTION 
R-503 is a mixture of trifluoromethane (R-23) and chlorotrifluoromethane 
(R-13). R-13 contains chlorine which has been theoretically linked to 
depletion of the Earth's ozone layer, and therefore it is desirable to 
find a replacement for R-503 that is chlorine-free. It has been discovered 
that certain mixtures of perfluoroethane (R-116) and R-23 can be used as a 
drop in replacement refrigerant for R-503. Specifically, as shown below, 
such mixtures include a mixture of 54 weight percent R-116 and 46 weight 
percent R-23. 
The azeotropic or azeotrope-like compositions, or mixtures, of the present 
invention comprise effective amounts of perfluoroethane (FC-116, or 
CF.sub.3 -CF.sub.3, boiling point=-78.3.degree. C.) and trifluoromethane 
(HFC-23, or CHF.sub.3, boiling point=-82.1.degree. C.), nitrous oxide 
(N.sub.2 O, boiling point=-88.5.degree. C.), carbon dioxide (CO.sub.2, 
boiling point=-78.5.degree. C.), or fluoromethane (HFC-41, or CH.sub.3 F, 
boiling point=-78.4.degree. C.) to form substantially constant boiling, 
azeotropic or azeotrope-like compositions. 
Effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, 
carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like 
composition, when defined in terms of weight percent of the components at 
a specific pressure or temperature, include the following. 
Substantially constant-boiling, azeotropic or azeotrope-like compositions 
of perfluoroethane and trifluoromethane comprise about 40 to 65 weight 
percent perfluoroethane and 35 to 60 weight percent trifluoromethane at 
100 psia (689.5 kPa). These compositions boil at about -46.4 
+/-0.5.degree. C. A preferred composition of the invention is the 
azeotrope which comprises about 53.8 weight percent perfluoroethane and 
about 46.2 weight percent trifluoromethane and which boils at 
-46.5.degree. C. at 100 psia, and which comprises about 55.9 weight 
percent perfluoroethane and about 44.1 weight percent trifluoromethane and 
which boils at -63.55.degree. C. at 49.316 psia. 
Substantially constant boiling, azeotropic or azeotrope-like compositions 
of perfluoroethane and nitrous oxide comprise about 35 to 55 weight 
percent perfluoroethane and about 45 to 65 percent nitrous oxide at 100 
psia. These compositions boil at about -51.1 +/-0.5.degree. C. A preferred 
composition of the invention is the azeotrope which comprises about 45.3 
weight percent perfluoroethane and about 54.7 weight percent nitrous oxide 
and which boils at -51.2.degree. C. at 100 psia, and which comprises about 
44.8 weight percent perfluoroethane and about 55.2 weight percent nitrous 
oxide and which boils at -45.55.degree. C. at 123.3 psia. 
Substantially constant boiling, azeotrope or azeotrope-like compositions of 
perfluoroethane and carbon dioxide comprise about 45 to 60 weight percent 
perfluoroethane and about 40 to 55 weight percent carbon dioxide at 100 
psia. These compositions boil at about -52.2 +/-0.5.degree. C. A preferred 
composition of the invention is the azeotrope which comprises about 51.4 
weight percent perfluoroethane and about 48.6 weight percent carbon 
dioxide and which boils at 52.2.degree. C. at 100 psia, and which 
comprises about 47.9 weight percent perfluoroethane and about 52.1 weight 
percent carbon dioxide and which boils at -45.55.degree. C. at 138.1 psia. 
Substantially constant boiling, azeotrope or azeotrope-like compositions of 
perfluoroethane and fluoromethane comprise about 78 to 82 weight percent 
perfluoroethane and 18 to 22 weight percent fluoromethane at 100 psia. 
These compositions boil at about -47.7 +/-0.5.degree. C. A preferred 
composition of the invention is the azeotrope which comprises about 80.3 
weight percent perfluoroethane and 19.7 weight percent fluoromethane and 
which boils at -47.6.degree. C. at 100 psia, and which comprises about 
80.2 weight percent perfluoroethane and 19.8 weight percent fluoromethane 
and which boils at -45.55.degree. C. at 108.2 psia. 
Effective amounts of perfluoroethane and trifluoromethane, nitrous oxide, 
carbon dioxide, or fluoromethane to form an azeotropic or azeotrope-like 
composition can also be defined as including amounts of these components 
such that the difference in dew point temperature and bubble point 
temperature of the composition is less than or equal to 1.degree. C. It is 
recognized in the art that a small difference, such as 1.degree. C., 
between the dew point temperature and the bubble point temperature of a 
composition at a particular pressure is an indication that the composition 
is azeotropic or azeotrope-like. It has been found unexpectedly that 
compositions some distance away from the true azeotropes of FC-116 and 
HFC-23, or FC-116 and N.sub.2 O, or FC-116 and CO.sub.2, or FC-116 and 
HFC-41 have differences in dew point and bubble point temperature of less 
than or equal to about 1.degree. C. 
Therefore, included in this invention are compositions of effective amounts 
of FC-116 and HFC-23 or compositions of effective amounts of FC-116 and 
N.sub.2 O, or compositions of effective amounts of FC-116 and CO.sub.2, or 
compositions of effective amounts of FC-116 and HFC-41, such that the 
compositions have a difference in dew point temperature and bubble point 
temperature of less than or equal to 1.degree. C. Such compositions 
include binary compositions of about 40 to 65 weight percent FC-116 and 
about 35 to 60 weight percent HFC-23; binary compositions of about 35 to 
55 weight percent FC-116 and about 45 to 65 weight percent N.sub.2 O; 
binary compositions of about 45 to 60 weight percent FC-116 and about 40 
to 55 weight percent CO.sub.2 ; and binary compositions of about 78 to 82 
weight percent FC-116 and about 18 to 22 weight percent HFC-41, all at 100 
psia. 
For purposes of this invention, "effective amount" is defined as the amount 
of each component of the inventive compositions which, when combined, 
results in the formation of an azeotropic or azeotrope-like composition. 
This definition includes the amounts of each component, which amounts may 
vary depending on the pressure applied to the composition so long as the 
azeotropic or azeotrope-like compositions continue to exist at the 
different pressures, but with possible different boiling points. 
Therefore, effective amount includes the amounts, such as may be expressed 
in weight percentages, of each component of the compositions of the 
instant invention which form azeotropic or azeotrope-like compositions at 
pressures other than the pressure described herein. 
By "azeotropic or azeotrope-like" composition is meant a constant boiling, 
or substantially constant boiling, liquid admixture of two or more 
substances that behaves as a single substance. One way to characterize an 
azeotropic or azeotrope-like composition is that the vapor produced by 
partial evaporation or distillation of the liquid has substantially the 
same composition as the liquid from which it was evaporated or distilled, 
that is, the admixture distills/refluxes without substantial composition 
change. Constant boiling or substantially constant boiling compositions, 
which are characterized as azeotropic or azeotrope-like, exhibit either a 
maximum or minimum boiling point, as compared with that of the 
nonazeotropic mixtures of the same components. 
For the purposes of this discussion, azeotropic or constant-boiling is 
intended to mean also essentially azeotropic or essentially-constant 
boiling. In other words, included within the meaning of these terms are 
not only the true azeotropes described above, but also other compositions 
containing the same components in different proportions, which are true 
azeotropes at other temperatures and pressures, as well as those 
equivalent compositions which are part of the same azeotropic system and 
are azeotrope-like in their properties. As is well recognized in this art, 
there is a range of compositions which contain the same components as the 
azeotrope, which will not only exhibit essentially equivalent properties 
for refrigeration and other applications, but which will also exhibit 
essentially equivalent properties to the true azeotropic composition in 
terms of constant boiling characteristics or tendency not to segregate or 
fractionate on boiling. 
It is possible to characterize, in effect, a constant boiling admixture 
which may appear under many guises, depending upon the conditions chosen, 
by any of several criteria: 
The composition can be defined as an azeotrope of A, B, C (and D . . . ) 
since the very term "azeotrope" is at once both definitive and limitative, 
and requires that effective amounts of A, B, C (and D. . . ) for this 
unique composition of matter which is a constant boiling composition. 
It is well known by those skilled in the art, that, at different pressures, 
the composition of a given azeotrope will vary at least to some degree, 
and changes in pressure will also change, at least to some degree, the 
boiling point temperature. Thus, and azeotrope of A, B, C (and D. . . ) 
represents a unique type of relationship but with a variable composition 
which depends on temperature and/or pressure. Therefore, compositional 
ranges, rather than fixed compositions, are often used to define 
azeotropes. 
The composition can be defined as a particular weight percent relationship 
or mole percent relationship of A, B, C (and D. . . ), while recognizing 
that such specific values point out only one particular relationship and 
that in actuality, a series of such relationships, represented by A, B, C 
(and D. . . ) actually exist for a given azeotrope, varied by the 
influence of pressure. 
An azeotrope of A, B, C (and D. . . ) can be characterized by defining the 
compositions as an azeotrope characterized by a boiling point at a given 
pressure, thus giving identifying characteristics without unduly limiting 
the scope of the invention by a specific numerical composition, which is 
limited by and is only as accurate as the analytical equipment available. 
The azeotrope or azeotrope-like compositions of the present invention can 
be prepared by any convenient method including mixing or combining the 
desired amounts. A preferred method is to weigh the desired component 
amounts and thereafter combine them in an appropriate container.

Specific examples illustrating the invention are given below. Unless 
otherwise stated therein, all percentages are by weight. It is to be 
understood that these examples are merely illustrative and in no way are 
to be interpreted as limiting the scope of the invention. 
FC-116 AND HFC-23 
EXAMPLE 1 
A phase study was made on perfluoroethane and trifluoromethane, wherein the 
composition was varied and the vapor pressures measured, at a constant 
temperature of -63.55.degree. C. An azeotropic composition was obtained as 
evidenced by the maximum vapor pressure observed and was identified as 
follows: 
Perfluoroethane=55.9 weight percent 
Trifluoromethane=44.1 weight percent 
Vapor pressure=49.316 psia (340.0 kPa) at -63.55.degree. C. 
EXAMPLE 2 
Phase studies on perfluoroethane and trifluoromethane at other temperatures 
and pressures disclose the following azeotropic compositions: 
Perfluoroethane=53.8 weight percent 
Trifluoromethane=46.2 weight percent 
Vapor pressure=100 psia at -46.5.degree. C. 
Perfluoroethane=41.1 weight percent 
Trifluoroethane=58.9 weight percent 
Vapor pressure=14.7 psia (101.3 kPa) at -86.9.degree. C. 
EXAMPLE 3 
The novel azeotropic or azeotrope-like compositions of the present 
invention exhibit a higher vapor pressure than either of the two 
constituents and exhibit dew and bubble points with virtually no 
temperature differentials. As is well known in the art, a small difference 
between dew point and bubble point temperatures is an indication of the 
azeotrope-like behavior of compositions. 
A study of dew point and bubble point temperatures for various compositions 
indicates that the differences in dew point and bubble point temperatures 
of the azeotrope-like compositions of the invention are very small with 
respect to the differences in dew point and bubble point temperatures of 
several known, nonazeotropic, binary compositions, namely, (50+50) weight 
percent compositions of pentafluoroethane (HFC-125) and 
1,1,1,2-tetrafluoroethane (HFC134a), and (50+50) weight percent 
compositions of chlorodifluoromethane (HCFC22) and 
1-chloro-1,1-difluoroethane (HCFC-142b). These data confirm the 
azeotrope-like behavior of the compositions of this invention. 
TABLE 1 
______________________________________ 
Temperatures (.degree.C.) at 100 psia 
Refrigerant Composition 
Bubble Point Dew Point 
Delta T 
______________________________________ 
HFC-125 + HFC-134a 
15.6 19.8 4.2 
(50 + 50) 
HCFC-22 + HFC-142b 
23.3 33.8 10.5 
(50 + 50) 
FC-116 + HFC-23 
-46.4 -46.4 0.0 
(54 + 46) 
FC-116 + HFC-23 
-46.3 -45.5 0.8 
(40 + 60) 
FC-116 + HFC-23 
-46.5 -46.4 0.1 
(50 + 50) 
FC-116 + HFC-23 
-46.4 -46.1 0.3 
(60 + 40) 
FC-116 + HFC-23 
-46.3 -45.4 0.9 
(65 + 35) 
______________________________________ 
Temperatures (.degree.C.) at 14.7 psia 
Refrigerant Composition 
Dew Point Bubble Point 
Delta T 
______________________________________ 
FC-116 + HFC-23 
-86.0 -86.8 0.8 
(69 + 31) 
FC-116 + HFC-23 
-85.9 -86.8 0.9 
(44 + 56) 
FC-116 + HFC-23 
-86.7 -86.9 0.2 
(54 + 46) 
______________________________________ 
EXAMPLE 4 
A study compares the refrigeration properties of an azeotropic composition 
of the invention with Refrigerant-503, which is 40.1 weight percent R-23 
and 59.9 weight percent R-13, and perfluoroethane (FC-116). The 
refrigeration capacity is based on a compressor with a fixed displacement 
of 3.5 cubic feet per minute. The data are based on a refrigeration cycle 
with a suction line heat exchanger. 
TABLE 2 
______________________________________ 
COMISON OF REFRIGERATION PERFORMANCES 
Refrig. FC-116/HFC-23 (wt percents) 
503 FC-116 (58/42) (54/46) 
(50/50) 
______________________________________ 
Evaporator 
-80.0 -80.0 -80.0 -80.0 -80.0 
Temp, .degree.F. 
Evaporator 
54.4 32.0 52.8 52.6 52.0 
Pres, psia 
Condenser -10.0 -10.0 -10.0 -10.0 -10.0 
Temp, .degree.F. 
Condenser 218.0 138.3 213.4 214.0 213.7 
Pres, psia 
Return Gas 
-60.0 -60.0 -60.0 -60.0 -60.0 
Temp, .degree.F. 
Compressor 
51.8 7.2 33.1 35.9 38.8 
Discharge, .degree.F. 
Coefficient 
3.8 3.6 3.7 3.7 3.7 
of Performance 
Capacity 204 113 187.9 190 191.3 
Btu/min 
______________________________________ 
Capacity is intended to mean the change in enthalpy of the refrigerant in 
the evaporator per pound of refrigerant circulated, i.e., the heat removed 
by the refrigerant in the evaporator per time. 
Coefficient of performance (COP) is intended to mean the ratio of the 
capacity to the compressor work. It is a measure of refrigerant energy 
efficiency. 
For a refrigeration cycle typified by the above conditions, both the COP 
and capacity increase by adding HFC-23 to FC-116. These results show that 
a composition of FC-116 and HFC-23 improves the capacity and energy 
efficiency of a refrigeration cycle when compared to FC-116 alone. 
FC-116 AND NITROUS OXIDE 
EXAMPLE 5 
A phase study was made on perfluoroethane and nitrous oxide, wherein the 
composition was varied and the vapor pressures measured, at a constant 
temperature of -45.55.degree. C. An azeotropic composition was obtained as 
evidenced by the maximum vapor pressure observed and was identified as 
follows: 
Perfluoroethane=44.8 weight percent 
Nitrous oxide=55.2 weight percent 
Vapor pressure=123.31 (850.2 kPa) at -45.55.degree. C. 
EXAMPLE 6 
A second phase study on perfluoroethane and nitrous oxide discloses the 
following azeotropic composition: 
Perfluoroethane=45.3 weight percent 
Nitrous oxide=54.7 weight percent 
Vapor pressure=100 psia at -51.2.degree. C. 
EXAMPLE 7 
A study as in Example 3 of dew point temperatures and bubble point confirms 
the azeotropic or azeotrope-like behavior of compositions of FC-116 and 
N.sub.2 O. 
TABLE 3 
______________________________________ 
Temperatures (.degree.C.) at 100 psia 
Refrigerant Composition 
Bubble Point Dew Point 
Delta T 
______________________________________ 
HFC-125 + HFC-134a 
15.6 19.8 4.2 
(50 + 50) 
HCFC-22 + HCFC-142b 
23.3 33.8 10.5 
(50 + 50) 
FC-116 + N.sub.2 O 
-51.1 -50.8 0.3 
(35 + 65) 
FC-116 + N.sub.2 O 
-51.2 -51.0 0.2 
(40 + 60) 
FC-116 + N.sub.2 O 
-51.2 -51.0 0.2 
(50 + 50) 
FC-116 + N.sub.2 O 
-51.1 -50.6 0.5 
(55 + 45) 
______________________________________ 
EXAMPLE 8 
A study as in Example 4 compares the refrigeration properties of an 
azeotropic composition of the invention with Refrigerant-503 and 
perfluoroethane (FC-116). 
TABLE 4 
______________________________________ 
COMISON OF REFRIGERATION PERFORMANCES 
Refrig. FC-116/N.sub.2 O (wt. percents) 
503 FC-116 (45/55) 
______________________________________ 
Evaporator 
-80.0 -80.0 -80.0 
Temp, .degree.F. 
Evaporator 
54.4 32.0 65.2 
Pres, psia 
Condenser -10.0 -10.0 -10.0 
Temp, .degree.F. 
Condenser 218.0 138.3 257.0 
Pres, psia 
Return Gas 
-60.0 -60.0 -60.0 
Temp, .degree.F. 
Compressor 
51.8 7.2 58.6 
Discharge, .degree.F. 
Coefficient 
3.8 3.6 3.9 
of Performance 
Capacity 204 113 252 
Btu/min 
______________________________________ 
For a refrigeration cycle typified by the above conditions, the capacity 
and the COP of FC-116 is increased by adding N.sub.2 O to the FC-116. 
These results show that a composition of FC-116 and N.sub.2 O improves the 
capacity of a refrigeration cycle when compared to Refrigerant 503. 
FC-116 AND CARBON DIOXIDE 
EXAMPLE 9 
A phase study was made on perfluoroethane and carbon dioxide, wherein the 
composition was varied and the vapor pressure measured, at a constant 
temperature of -45.55.degree. C. An azeotropic composition was obtained as 
evidenced by the maximum vapor pressure observed and was identified as 
follows: 
Perfluoroethane=47.9 weight percent 
Carbon dioxide=52.1 weight percent 
Vapor pressure=138.1 psia (952.2 kPa) at -45.55.degree. C. 
EXAMPLE 10 
A second phase study on perfluoroethane and carbon dioxide discloses the 
following azeotropic composition: 
Perfluoroethane=51.4 weight percent 
Carbon dioxide=48.6 weight percent 
Vapor pressure=100 psia at -52.2.degree. C. 
EXAMPLE 11 
A study as in Example 3 shows that novel azeotropic or azeotrope-like 
compositions of FC-116 and CO.sub.2 exhibit dew and bubble points with 
virtually no temperature differentials. 
TABLE 5 
______________________________________ 
Temperatures (.degree.C.) at 100 psia 
Refrigerant Composition 
Bubble Point Dew Point 
Delta T 
______________________________________ 
HFC-125 + HFC-134a 
15.6 19.8 4.2 
(50 + 50) 
HCFC-22 + HFC-142b 
23.3 33.8 10.5 
(50 + 50) 
FC-116 + CO.sub.2 
-52.2 -52.0 0.2 
(45 + 55) 
FC-116 + CO.sub.2 
-52.2 -52.2 0.0 
(50 + 50) 
FC-116 + CO.sub.2 
-52.2 -51.6 0.6 
(60 + 40) 
______________________________________ 
EXAMPLE 12 
A study as in Example 4 compares the refrigerant properties of the 
azeotropic compositions of the invention with Refrigerant-503 and 
perfluoroethane (FC-116). 
TABLE 6 
______________________________________ 
Refrig. FC-116/CO.sub.2 (wt. percents) 
503 FC-116 (50/50) 
______________________________________ 
Evaporator 
-80.0 -80.0 -80.0 
Temp, .degree.F. 
Evaporator 
54.4 32.0 61.6 
Pres, psia 
Condenser -10.0 -10.0 -10.0 
Temp, .degree.F. 
Condenser 218.0 138.3 312.0 
Pres, psia 
Return Gas 
-60.0 -60.0 -60.0 
Temp, .degree.F. 
Compressor 
51.8 7.2 74.4 
Discharge, .degree.F. 
Coefficient 
3.8 3.6 3.2 
of Performance 
Capacity 204 113 236 
Btu/min 
______________________________________ 
For a refrigeration cycle typified by the above conditions, the capacity 
increases by adding CO.sub.2 to FC-116. These results show that a 
composition of FC116 and CO.sub.2 improves the capacity of a refrigeration 
cycle when compared to FC116 alone and to Refrigerant 503. 
FC-116 AND HFC-41 
EXAMPLE 13 
A phase study was made on perfluoroethane and fluoromethane, wherein the 
composition was varied and the vapor pressures measured at a constant 
temperature of -45.55.degree. C. An azeotropic composition was obtained as 
evidenced by the maximum vapor pressure observed and was identified as 
follows: 
Perfluoroethane=80.2 weight percent 
Fluoromethane=19.8 weight percent 
Vapor pressure=108.21 psia (746.1 kPa) at -45.55.degree. C. 
EXAMPLE 14 
A second phase study on perfluoroethane and fluoromethane discloses the 
following azeotropic composition: 
Perfluoroethane=80.3 weight percent 
Fluoroethane=19.7 weight percent 
Vapor pressure=100 psia at -47.6.degree. C. 
EXAMPLE 15 
A study as in Example 3 shows that novel azeotropic or azeotrope-like 
compositions of FC-116 and HFC-41 exhibit dew and bubble point 
temperatures with small temperature differentials. 
TABLE 7 
______________________________________ 
Temperatures (.degree.C.) at 100 psia 
Refrigerant Composition 
Bubble Point Dew Point 
Delta T 
______________________________________ 
HFC-125 + HFC-134a 
15.6 19.8 4.2 
(50 + 50) 
HCFC-22 + HCFC-142b 
23.3 33.8 10.5 
(50 + 50) 
FC-116 + HFC-41 
-47.7 -47.3 0.3 
(82 + 18) 
FC-116 + HFC-41 
-47.7 -47.1 0.6 
(78 + 22) 
FC-116 + HFC-41 
-47.7 -47.7 0.0 
(80 + 20) 
______________________________________ 
EXAMPLE 16 
A study as in Example 4 compares the refrigeration properties of the 
azeotropic compositions of the invention with Refrigerant 503 and FC-116. 
TABLE 8 
______________________________________ 
COMISON OF REFRIGERATION PERFORMANCES 
Refrig. FC-116/HFC-41 (wt. percents) 
503 FC-116 (80/20) 
______________________________________ 
Evaporator 
-80.0 -80.0 -80.0 
Temp, .degree.F. 
Evaporator 
54.4 32.0 53.7 
Pres, psia 
Condenser -10.0 -10.0 -10.0 
Temp, .degree.F. 
Condenser 218.0 138.3 221.0 
Pres, psia 
Return Gas 
-60.0 -60.0 -60.0 
Temp, .degree.F. 
Compressor 
51.8 7.2 36.0 
Discharge, .degree.F. 
Coefficient 
3.8 3.6 3.5 
of Performance 
Capacity 204 113 184 
Btu/min 
______________________________________ 
For a refrigeration cycle typified by the above conditions, the capacity 
increases by adding HFC-41 to FC-1 16. These results show that a 
composition of FC-116 and HFC-41 increases the capacity of a refrigeration 
cycle versus FC-116 alone. 
The novel azeotrope or azeotrope-like compositions of FC-116 and HFC-23 or 
FC-116 and N.sub.2 O or FC-116 and CO.sub.2 or FC-116 and HFC-41 may be 
used to produce refrigeration by condensing the compositions and 
thereafter evaporating the condensate in the vicinity of the body to be 
cooled. 
The novel azeotrope or azeotrope-like compositions may also be used to 
produce heat by condensing the refrigerant in the vicinity of the body to 
be heated and thereafter evaporating the refrigerant. 
The use of azeotropic or azeotrope-like compositions eliminates the problem 
of component fractionation and handling in systems operations, because 
these compositions behave essentially as a single substance. Several of 
the novel azeotrope-like compositions also offer the advantage of being 
essentially nonflammable. 
In addition to refrigeration applications, the novel constant boiling 
compositions of the invention are also useful as aerosol propellants, heat 
transfer media, gaseous dielectrics, fire extinguishing agents, expansion 
agents for polyolefins and polyurethanes and as power cycle working 
fluids. 
Additives such as lubricants, corrosion inhibitors, stabilizers, dyes, and 
other appropriate materials may be added to the novel compositions of the 
invention for a variety of purposes provided they do not have an adverse 
influence on the composition, for their intended applications.