HK1008965B - Refrigerant compositions including hexafluoropropane and a hydrofluorocarbon - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of pending U.S. patent application Serial No. 08/039,563, filed March 29, 1993.

FIELD OF THE INVENTION

This invention relates to compositions of mixture of hydrofluorocarbons. These compositions are useful as cleaning agents, expansion agents for polyolefins and polyurethanes, aerosol propellants, refrigerants, 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. Such refrigerants include dichlorodifluoromethane (CFC-12) and chlorodifluoromethane (HCFC-22).

In recent years it has been pointed out that certain kinds of fluorinated hydrocarbon refrigerants released into the atmosphere may adversely affect the stratospheric ozone layer. Although this proposition has not yet been completely established, there is a movement toward the control of the use and the production of certain chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) under an international agreement.

Accordingly, there is a demand for the development of refrigerants that have a lower ozone depletion potential than existing refrigerants while still achieving an acceptable performance in refrigeration applications. Hydrofluorocarbons (HFCs) have been suggested as replacements for CFCs and HCFCs since HFCs have no chlorine and therefore have zero ozone depletion potential.

In refrigeration applications, a refrigerant is often lost during operation through leaks in shaft seals, hose connections, soldered joints and broken lines. In addition, the refrigerant may be released to the atmosphere during maintenance procedures on refrigeration equipment. If the refrigerant is not a pure component or an azeotropic or azeotrope-like composition, the refrigerant composition may change when leaked or discharged to the atmosphere from the refrigeration equipment, which may cause the refrigerant to become flammable or to have poor refrigeration performance.

Accordingly, it is desirable to use as a refrigerant a single fluorinated hydrocarbon or an azeotropic or azeotrope-like composition that includes one or more fluorinated hydrocarbons.

Fluorinated hydrocarbons may also be used as a cleaning agent or solvent to clean, for example, electronic circuit boards. It is desirable that the cleaning agents be azeotropic or azeotrope-like because in vapor degreasing operations the cleaning agent is generally redistilled and reused for final rinse cleaning.

Azeotropic or azeotrope-like compositions that include a fluorinated hydrocarbon are also useful as blowing agents in the manufacture of closed-cell polyurethane, phenolic and thermoplastic foams, as propellants in aerosols, 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, as carrier fluids that may be used, for example, to place a fine film of lubricant on metal parts, as buffing abrasive agents 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 including chlorine-type developing agents, or as strippers for photoresists when used with, for example, a chlorohydrocarbon such as 1,1,1-trichloroethane or trichloroethylene.

SUMMARY OF THE INVENTION

The present invention relates to the discovery of refrigerant compositions of hexafluoropropane and a hydrofluorocarbon, with the hydrofluorocarbon being hexafluoropropane, pentafluoropropane, tetrafluoropropane, trifluoropropane, difluoropropane, fluoropropane, or HFC-356mmz. These compositions are also useful as cleaning agents, expansion agents for polyolefins and polyurethanes, 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. Further, the invention relates to the discovery of binary azeotropic or azeotrope-like compositions comprising effective amounts of hexafluoropropane and hexafluoropropane, pentafluoropropane, tetrafluoropropane, trifluoropropane, difluoropropane, fluoropropane, or HFC-356mmz to form an azeotropic or azeotrope-like composition.

BRIEF DESCRIPTION OF THE DRAWINGS

• Figure 1 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-236fa at 25°C;
• Figure 2 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-245eb at 25°C;
• Figure 3 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-245fa at 25°C;
• Figure 4 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-254eb at 25°C;
• Figure 5 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-263ca at 25°C;
• Figure 6 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-263fb at 25°C;
• Figure 7 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-272ca at 25°C;
• Figure 8 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-272fb at 25°C;
• Figure 9 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-281ea at 25°C;
• Figure 10 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ca and HFC-356mmz at 25°C;
• Figure 11 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-236ea at 25°C;
• Figure 12 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-236fa at 25°C;
• Figure 13 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-245fa at 25°C;
• Figure 14 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-254cb at 25°C;
• Figure 15 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-254eb at 25°C;
• Figure 16 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-263fb at 25°C;
• Figure 17 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-272ca at 25°C;
• Figure 18 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-281ea at 25°C;
• Figure 19 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236cb and HFC-281fa at 25°C;
• Figure 20 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ea and HFC-236fa at 25°C;
• Figure 21 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ea and HFC-245cb at 25°C;
• Figure 22 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ea and HFC-263fb at 25°C;
• Figure 23 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ea and HFC-272ca at 25°C;
• Figure 24 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ea and HFC-272fb at 25°C;
• Figure 25 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ea and HFC-281ea at 25°C;
• Figure 26 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236ea and HFC-281fa at 25°C;
• Figure 27 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-245ca at 25°C;
• Figure 28 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-245eb at 25°C;
• Figure 29 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-254ca at 25°C;
• Figure 30 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-254cb at 25°C;
• Figure 31 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-254eb at 25°C;
• Figure 32 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-272ca at 25°C;
• Figure 33 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-272ea at 25°C;
• Figure 34 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-281ea at 25°C; and
• Figure 35 is a graph of the vapor/liquid equilibrium curve for mixtures of HFC-236fa and HFC-281fa at 25°C.

DETAILED DESCRIPTION

The present invention relates to the following compositions:

• (a) 1,1,2,2,3,3-hexafluoropropane (HFC-236ca) and 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,2-tetrafluoropropane (HFC-254eb), 1,2,2-trifluoropropane (HFC-263ca), 1,1,1-trifluoropropane (HFC-263fb), 2,2-difluoropropane (HFC-272ca), 1,1-difluoropropane (HFC-272fb), 2-fluoropropane (HFC-281ea) or (CF3)2CHCH3 (HFC-356mmz);
• (b) 1,1,1,2,2,3-hexafluoropropane (HFC-236cb) and 1,1,2,3,3,3-hexafluoropropane (HFC-236ea), HFC-236fa, HFC-245fa, 1,1,2,2-tetrafluoropropane (HFC-254cb), HFC-254eb, HFC-263fb, HFC-272ca, HFC-272fb, HFC-281ea or 1-fluoropropane (HFC-281fa);
• (c) HFC-236ea and HFC-236fa, 1,1,1,2,2-pentafluoropropane (HFC-245cb), HFC-263fb, HFC-272ca, HFC-272fb, HFC-281ea or HFC-281fa; or
• (d) HFC-236fa and 1,1,2,2,3-pentafluoropropane (HFC-245ca), HFC-245eb, 1,2,2,3-tetrafluoropropane (HFC-254ca), HFC-254cb, HFC-254eb, HFC-272ca, HFC-272ea, HFC-281ea or HFC-281fa.

1-99 wt.% of each of the components of the compositions can be used as refrigerants. Further, the present invention also relates to the discovery of azeotropic or azeotrope-like compositions of effective amounts of each of the above mixtures to form an azeotropic or azeotrope-like composition.

By "azeotropic" composition is meant a constant boiling liquid admixture of two or more substances that behaves as a single substance. One way to characterize an azeotropic composition is that the vapor produced by partial evaporation or distillation of the liquid has the same composition as the liquid from which it was evaporated or distilled, that is, the admixture distills/refluxes without compositional change. Constant boiling compositions are characterized as azeotropic because they exhibit either a maximum or minimum boiling point, as compared with that of the non-azeotropic mixtures of the same components.

By "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 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.

It is recognized in the art that a composition is azeotrope-like if, after 50 weight percent of the composition is removed such as by evaporation or boiling off, the difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed is less than 10 percent, when measured in absolute units. By absolute units, it is meant measurements of pressure and, for example, psia, atmospheres, bars, torr, dynes per square centimeter, millimeters of mercury, inches of water and other equivalent terms well known in the art. If an azeotrope is present, there is no difference in vapor pressure between the original composition and the composition remaining after 50 weight percent of the original composition has been removed.

Therefore, included in this invention are compositions of effective amounts of

• (a) 1,1,2,2,3,3-hexafluoropropane (HFC-236ca) and 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,2,3-pentafluoropropane (HFC-245eb), 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,2-tetrafluoropropane (HFC-254eb), 1,2,2-trifluoropropane (HFC-263ca), 1,1,1-trifluoropropane (HFC-263fb), 2,2-difluoropropane (HFC-272ca), 1,1-difluoropropane (HFC-272fb), 2-fluoropropane (HFC-281ea) or (CF3)2CHCH3 (HFC-356mmz);
• (b) 1,1,1,2,2,3-hexafluoropropane (HFC-236cb) and 1,1,2,3,3,3-hexafluoropropane (HFC-236ea), HFC-236fa, HFC-245fa, 1,1,2,2-tetrafluoropropane (HFC-254cb), HFC-254eb, HFC-263fb, HFC-272ca, HFC-272fb, HFC-281ea or HFC-281fa;
• (c) HFC-236ea and HFC-236fa, HFC-245cb, HFC-263fb, HFC-272ca, HFC-272fb, HFC-281ea or HFC-281fa; or
• (d) HFC-236fa and HFC-245ca, HFC-245eb, HFC-254ca, HFC-254cb, HFC-254eb, HFC-272ca, HFC-272ea, HFC-281ea or HFC-281fa;

such that after 50 weight percent of an original composition is evaporated or boiled off to produce a remaining composition, the difference in the vapor pressure between the original composition and the remaining composition is 10 percent or less.

For compositions that are azeotropic, there is usually some range of compositions around the azeotrope point that, for a maximum boiling azeotrope, have boiling points at a particular pressure higher than the pure components of the composition at that pressure and have vapor pressures at a particular temperature lower than the pure components of the composition at that temperature, and that, for a minimum boiling azeotrope, have boiling points at a particular pressure lower than the pure components of the composition at that pressure and have vapor pressures at a particular temperature higher than the pure components of the composition at that temperature. Boiling temperatures and vapor pressures above or below that of the pure components are caused by unexpected intermolecular forces between and among the molecules of the compositions, which can be a combination of repulsive and attractive forces such as van der Waals forces and hydrogen bonding.

The range of compositions that have a maximum or minimum boiling point at a particular pressure, or a maximum or minimum vapor pressure at a particular temperature, may or may not be coextensive with the range of compositions that have a change in vapor pressure of less than about 10% when 50 weight percent of the composition is evaporated. In those cases where the range of compositions that have maximum or minimum boiling temperatures at a particular pressure, or maximum or minimum vapor pressures at a particular temperature, are broader than the range of compositions that have a change in vapor pressure of less than about 10% when 50 weight percent of the composition is evaporated, the unexpected intermolecular forces are nonetheless believed important in that the refrigerant compositions having those forces that are not substantially constant boiling may exhibit unexpected increases in the capacity or efficiency versus the components of the refrigerant composition.

The components of the compositions of this invention have the following vapor pressures at 25°C.

Components	Psia	kPa
HFC-236ca	24.9	172
HFC-236cb	33.6	232
HFC-236ea	29.8	206
HFC-236fa	39.4	271
HFC-245ca	14.2	98
HFC-245cb	67.4	465
HFC-245eb	16.9	117
HFC-245fa	21.6	149
HFC-254ca	13.7	95
HFC-254cb	34.2	236
HFC-254eb	34.8	240
HFC-263ca	18.2	126
HFC-263fb	54.0	372
HFC-272ca	34.5	238
HFC-272ea	20.8	143
HFC-272fb	26.5	182
HFC-281ea	47.1	325
HFC-281fa	37.7	260
HFC-356mmz	16.6	114

Substantially constant boiling, azeotropic or azeotrope-like compositions of this invention comprise the following (all compositions are measured at 25°C):

COMPONENTS	WEIGHT RANGES (wt.%/wt/%)	PREFERRED (wt.%/wt.%)
HFC-236ca/HFC-236fa	1-99/1-99	1-80/20-99
HFC-236ca/HFC-245eb	1-99/1-99	1-85/15-99
HFC-236ca/HFC-245fa	1-99/1-99	20-99/1-80
HFC-236ca/HFC-254eb	1-99/1-99	40-99/1-60
HFC-236ca/HFC-263ca	1-99/1-99	20-99/1-80
HFC-236ca/HFC-263fb	1-62/38-99	1-62/38-99
HFC-236ca/HFC-272ca	1-81/19-99	20-81/19-80
HFC-236ca/HFC-272fb	1-99/1-99	30-99/1-70
HFC-236ca/HFC-281ea	1-78/22-99	1-78/22-99
HFC-236ca/HFC-356mmz	1-99/1-99	50-99/1-50
HFC-236cb/HFC-236ea	1-99/1-99	1-99/1-99
HFC-236cb/HFC-236fa	1-99/1-99	1-99/1-99
HFC-236cb/HFC-245fa	1-99/1-99	1-60/40-99
HFC-236cb/HFC-254cb	1-99/1-99	20-99/1-80
HFC-236cb/HFC-254eb	1-99/1-99	20-99/1-80
HFC-236cb/HFC-263fb	1-99/1-99	1-99/1-99
HFC-236cb/HFC-272ca	1-99/1-99	40-99/1-60
HFC-236cb/HFC-272fb	1-99/1-99	20-99/1-80
HFC-236cb/HFC-281ea	1-99/1-99	20-99/1-80
HFC-236cb/HFC-281fa	1-99/1-99	20-99/1-80
HFC-236ea/HFC-236fa	1-99/1-99	1-99/1-99
HFC-236ea/HFC-245cb	1-45/55-99	1-45/55-99
HFC-236ea/HFC-263fb	1-65/35-99	1-65/35-99
HFC-236ea/HFC-272ca	1-99/1-99	20-99/1-80
HFC-236ea/HFC-272fb	1-99/1-99	40-99/1-60
HFC-236ea/HFC-281ea	1-87/13-99	15-87/13-85
HFC-236ea/HFC-281fa	1-99/1-99	20-99/1-80
HFC-236fa/HFC-245ca	72-99/1-28	72-99/1-28
HFC-236fa/HFC-245eb	60-99/1-40	60-99/1-40
HFC-236fa/HFC-254ca	68-99/1-32	68-99/1-32
HFC-236fa/HFC-254cb	1-99.8/0.2-99	49-99.8/0.2-60
HFC-236fa/HFC-254eb	1-99/1-99	40-99/1-60
HFC-236fa/HFC-272ca	1-99/1-99	40-99/1-60
HFC-236fa/HFC-272ea	64-99/1-36	64-99/1-36
HFC-236fa/HFC-281ea	1-99/1-99	40-99/1-60
HFC-236fa/HFC-281fa	1-99/1-99	40-99/1-60

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 temperatures or pressures other than as described herein.

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, an 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.

EXAMPLE 1 Phase Study

A phase study shows the following compositions are azeotropic, all at 25°C.

Composition No.		Vapor Press. psia (kPa)
HFC-236ca/HFC-236fa	7.6/92.4	39.5	272
HFC-236ca/HFC-245eb	9.1/90.9	16.9	117
HFC-236ca/HFC-245fa	98.3/1.7	24.9	172
HFC-236ca/HFC-254eb	77.4/22.6	21.7	150
HFC-236ca/HFC-263ca	35.4/64.6	17.8	123
HFC-236ca/HFC-263fb	13.7/86.3	54.6	376
HFC-236ca/HFC-272ca	46.8/53.2	40.2	277
HFC-236ca/HFC-272fb	56.1/43.9	29.0	200
HFC-236ca/HFC-281ea	16.3/83.7	47.4	327
HFC-236ca/HFC-356mmz	78.1/21.9	25.8	178
HFC-236cb/HFC-236ea	36.7/63.3	27.6	190
HFC-236cb/HFC-236fa	28.2/71.8	41.7	288
HFC-236cb/HFC-245fa	25.6/74.4	20.5	141
HFC-236cb/HFC-254cb	52.1/47.9	28.8	199
HFC-236cb/HFC-254eb	39.0/61.0	35.2	243
HFC-236cb/HFC-263fb	19.0/81.0	55.0	379
HFC-236cb/HFC-272ca	58.2/41.8	41.3	285
HFC-236cb/HFC-272fb	45.0/55.0	26.1	180
HFC-236cb/HFC-281ea	39.1/60.9	48.9	337
HFC-236cb/HFC-281fa	56.1/43.9	40.4	279
HFC-236ea/HFC-236fa	17.6/82.4	41.4	285
HFC-236ea/HFC-245cb	3.7/96.3	67.6	466
HFC-236ea/HFC-263fb	20.0/80.0	56.2	387
HFC-236ea/HFC-272ca	50.0/50.0	41.7	288
HFC-236ea/HFC-272fb	75.0/25.0	31.0	214
HFC-236ea/HFC-281ea	33.9/66.1	48.7	336
HFC-236ea/HFC-281fa	44.8/55.2	39.9	275
HFC-236fa/HFC-245ca	98.0/2.0	39.5	272
HFC-236fa/HFC-245eb	90.4/9.6	40.6	280
HFC-236fa/HFC-254ca	92.4/7.6	40.8	281
HFC-236fa/HFC-254cb	99.8/0.2	39.4	272
HFC-236fa/HFC-254eb	74.4/25.6	41.5	286
HFC-236fa/HFC-272ca	79.3/20.7	40.6	280
HFC-236fa/HFC-272ea	88.9/11.1	43.2	298
HFC-236fa/HFC-281ea	62.5/37.5	54.0	372
HFC-236fa/HFC-281fa	75.3/24.7	48.4	334

EXAMPLE 2 Impact of Vapor Leakage on Vapor Pressure at 25°C

A vessel is charged with an initial composition at 25°C, and the initial vapor pressure of the composition is measured. The composition is allowed to leak from the vessel, while the temperature is held constant at 25°C, until 50 weight percent of the initial composition is removed, at which time the vapor pressure of the composition remaining in the vessel is measured. The results are summarized below.

WT%A/WT%B	INITIAL		50% LEAK		DELTA %P
	PSIA	KPA	PSIA	KPA
HFC-236ca/HFC-236fa
7.6/92.4	39.5	272	39.5	272	0.0
1/99	39.4	272	39.4	272	0.0
40/60	37.8	261	37.2	256	1.6
60/40	35.4	244	33.6	232	5.1
80/20	31.5	217	28.8	199	8.6
85/15	30.2	208	27.6	190	8.6
99/1	25.4	175	25.1	173	1.2
HFC-236ca/HFC-245eb
9.1/90.9	16.9	117	16.9	117	0.0
1/99	16.9	117	16.9	117	0.0
40/60	17.4	120	17.3	119	0.6
60/40	20.	138	19.1	132	4.5
85/15	22.5	155	21.4	148	4.9
99/1	24.8	171	24.8	171	0.0
HFC-236ca/HFC-245fa
98.3/1.7	24.9	172	24.9	172	0.0
99/1	24.9	172	24.9	172	0.0
60/40	24.4	168	24.3	168	0.4
40/60	23.7	163	23.6	163	0.4
20/80	22.8	157	22.7	157	0.4
1/99	21.7	150	21.7	150	0.0
HFC-236ca/HFC-254eb
77.4/22.6	21.7	150	21.7	150	0.0
90/10	23.	159	22.5	155	2.2
99/1	24.8	171	24.8	171	0.0
50/50	25.2	174	23.5	162	6.7
45/55	26.1	180	24.2	167	7.3
40/60	27.1	187	25.1	173	7.4
30/70	29.2	201	27.1	187	7.2
20/80	31.1	214	29.5	203	5.1
1/99	34.6	239	34.5	238	0.3
HFC-236ca/HFC-263ca
35.4/64.6	17.8	123	17.8	123	0.0
20/80	17.9	123	17.9	123	0.0
1/99	18.2	125	18.2	125	0.0
60/40	18.4	127	18.2	125	1.1
80/20	20.6	142	19.7	136	4.4
90/10	22.7	157	21.7	150	4.4
99/1	24.8	171	24.7	170	0.4
HFC-236ca/HFC-263fb
13.7/86.3	54.6	376	54.6	376	0.0
1/99	54.1	373	54.1	373	0.0
40/60	53.1	366	52.	359	2.1
60/40	49.8	343	45.4	313	8.8
65/35	48.5	334	42.7	294	12.
63/37	49.	338	43.8	302	10.6
62/38	49.3	340	44.4	306	9.9
HFC-236ca/HFC-272ca
46.8/53.2	40.2	277	40.2	277	0.0
20/80	38.8	268	37.5	259	3.4
1/99	34.9	241	34.6	239	0.9
10/90	37.2	256	35.8	247	3.8
70/30	39.	269	37.6	259	3.6
85/15	35.7	246	31.2	215	12.6
82/18	36.7	253	32.8	226	10.6
81/19	36.9	254	33.3	230	9.8
HFC-236ca/HFC-272fb
56.1/43.9	29.	200	29.	200	0.0
30/70	28.4	196	28.2	194	0.7
10/90	27.2	188	27.	186	0.7
1/99	26.5	183	26.5	183	0.0
80/20	28.2	194	27.9	192	1.1
99/1	25.2	174	25.1	173	0.4
HFC-236ca/HFC-281ea
16.3/83.7	47.4	327	47.4	327	0.0
1/99	47.2	325	47.2	325	0.0
40/60	46.8	323	46.5	321	0.6
60/40	45.	310	43.7	301	2.9
80/20	40.6	280	36.1	249	11.1
78/22	41.3	285	37.2	256	9.9
HFC-236ca/HFC-356mmz
78.1/21.9	25.8	178	25.8	178	0.0
90/10	25.6	177	25.5	176	0.4
99/1	25.	172	25.	172	0.0
50/50	24.9	172	24.3	168	2.4
30/70	23.	159	21.4	148	7.
20/80	21.6	149	19.5	134	9.7
18/82	21.2	146	19.2	132	9.4
10/90	19.5	134	17.8	123	8.7
1/99	16.9	117	16.7	115	1.2
HFC-236cb/HFC-236ea
36.7/63.3	27.6	190	27.6	190	0.0
20/80	28.3	195	28.1	194	0.7
1/99	29.9	206	29.9	206	0.0
60/40	28.7	198	28.4	196	4.5
80/20	30.9	213	30.4	210	1.6
99/1	33.5	231	33.4	230	0.3
HFC-236cb/HFC-236fa
28.2/71.8	41.7	288	41.7	288	0.0
15/85	41.3	285	41.2	284	0.2
1/99	39.6	273	39.5	272	0.3
60/40	40.	276	39.5	272	1.3
80/20	37.5	259	36.6	252	2.4
99/1	33.8	233	33.8	233	0.0
HFC-236cb/HFC-245fa
25.6/74.4	20.5	141	20.5	141	0.0
10/90	21.3	147	21.1	145	0.9
1/99	21.7	150	21.7	150	0.0
60/40	24.4	168	22.7	157	7.
65/35	25.4	175	23.5	162	7.5
70/30	26.5	183	24.4	168	7.9
80/20	28.8	199	26.9	185	6.6
99/1	33.4	230	33.2	229	0.6
HFC-236cb/HFC-254cb
52.1/47.9	28.8	199	28.8	199	0.0
80/20	30.7	212	30.3	209	1.3
99/1	33.4	230	33.4	230	0.0
20/80	31.7	219	30.9	213	2.5
1/99	34.2	236	34.2	236	0.0
HFC-236cb/HFC-254eb
39/61	35.2	243	35.2	243	0.0
20/80	35.1	242	35.1	242	0.0
1/99	34.8	240	34.8	240	0.0
70/30	34.8	240	34.8	240	0.0
90/10	34.2	236	34.1	235	0.3
99/1	33.7	232	33.7	232	0.0
HFC-236cb/HFC-263fb
19/81	55.	379	55.	379	0.0
10/90	54.8	378	54.8	378	0.0
1/99	54.1	373	54.1	373	0.0
50/50	53.	365	51.7	356	2.5
80/20	45.4	313	41.3	285	9.
82/18	44.6	308	40.4	279	9.4
84/16	43.7	301	39.5	272	9.6
85/15	43.2	298	39.1	270	9.5
99/1	34.4	237	33.9	234	1.5
HFC-236cb/HFC-272ca
58.2/41.8	41.3	285	41.3	285	0.0
80/20	40.	276	39.3	271	1.8
99/1	34.2	236	33.9	234	0.9
20/80	38.8	268	37.4	258	3.6
1/99	34.8	240	34.6	239	0.6
HFC-236cb/HFC-272fb
45/55	26.1	180	26.1	180	0.0
20/80	26.7	184	26.7	184	0.0
1/99	26.7	184	26.5	183	0.7
75/25	28.1	194	27.5	190	2.1
99/1	33.3	230	33.2	229	0.3
HFC-236cb/HFC-281ea
39.1/60.9	48.9	337	48.9	337	0.0
20/80	48.5	334	48.4	334	0.2
1/99	47.2	325	47.2	325	0.0
70/30	47.1	325	46.1	318	2.1
85/15	43.5	300	41.1	283	5.5
92/8	40.1	276	37.6	259	6.2
99/1	34.7	239	34.1	235	1.7
HFC-236cb/HFC-281fa
56.1/43.9	40.4	279	40.4	279	0.0
80/20	39.2	270	38.8	268	1.
99/1	34.1	235	34.	234	0.3
20/80	39.1	270	38.9	268	0.5
1/99	37.8	261	37.8	261	0.0
HFC-236ea/HFC-236fa
17.6/82.4	41.4	285	41.4	285	0.0
1/99	39.7	274	39.6	273	0.3
40/60	40.2	277	39.6	273	1.5
60/40	37.6	259	36.3	250	3.5
80/20	34.1	235	32.8	226	3.8
99/1	30.1	208	30.0	207	0.03
HFC-236ea/HFC-245cb
3.7/96.3	67.6	466	67.6	466	0.0
1/99	67.5	465	67.5	465	0.0
20/80	65.9	454	64.8	447	1.7
40/60	61.1	421	56.3	388	7.9
45/55	59.5	410	53.6	370	9.9
46/54	59.2	408	53.0	365	10.5
HFC-236ea/HFC-263fb
20.0/80.0	56.2	387	56.2	387	0.0
1/99	54.3	374	54.2	374	0.2
50/50	53.7	370	51.5	354	4.1
65/35	50.2	346	45.4	313	9.6
66/34	49.9	344	44.9	310	10.0
HFC-236ea/HFC-272ca
50.0/50.0	41.7	288	41.7	288	0.0
25/75	40.6	280	39.2	270	3.4
1/99	35.0	241	34.6	239	1.1
75/25	40.0	276	38.7	267	3.2
99/1	30.6	211	30.1	208	1.6
HFC-236ea/HFC-272fb
75.0/25.0	31.0	214	31.0	214	0.0
99/1	30.0	207	29.9	206	0.3
40/60	29.9	206	29.6	204	1.0
20/80	28.5	197	28.0	193	1.8
1/99	26.6	183	26.5	183	0.4
HFC-236ea/HFC-281ea
33.9/66.1	48.7	336	48.7	336	0.0
15/85	48.2	332	48.1	332	0.2
1/99	47.2	325	47.2	325	0.0
60/40	47.5	328	46.8	323	1.5
80/20	43.7	301	40.5	279	7.3
87/13	40.8	281	36.8	254	9.8
88/12	40.3	278	36.2	250	10.2
HFC-236ea/HFC-281fa
44.8/55.2	39.9	275	39.9	275	0.0
20/80	39.2	270	39.0	269	0.5
1/99	37.8	261	37.8	261	0.0
60/40	39.6	273	39.4	272	0.5
80/20	37.4	258	36.4	251	2.7
99/1	30.5	210	30.2	208	1.0
HFC-236fa/HFC-245ca
98/2	39.5	272	39.5	272	0.0
99/1	39.4	272	39.4	272	0.0
60/40	32.9	227	27.4	189	16.7
70/30	35.4	244	31.5	217	11.
72/28	35.8	247	32.4	223	9.5
HFC-236fa/HFC-245eb
90.4/9.6	40.6	280	40.6	280	0.0
99/1	39.7	274	39.6	273	0.3
60/40	37.6	259	34.1	235	9.3
59/41	37.5	259	33.7	232	10.1
HFC-236fa/HFC-254ca
92.4/7.6	40.8	281	40.8	281	0.0
99/1	39.9	275	39.6	273	0.8
60/40	36.9	254	30.7	212	16.8
70/30	38.7	267	35.6	245	8.
67/33	38.3	264	34.3	236	10.4
68/32	38.4	265	34.8	240	9.4
HFC-236fa/HFC-254cb
99.8/0.2	39.4	272	39.4	272	0.0
70/30	38.8	268	38.7	267	0.3
40/60	37.3	257	37.1	256	0.5
20/80	35.9	248	35.7	246	0.6
1/99	34.3	236	34.2	236	0.3
HFC-236fa/HFC-254eb
74.4/25.6	41.5	286	41.5	286	0.0
90/10	40.9	282	40.7	281	0.5
99/1	39.6	273	39.5	272	0.3
40/60	39.7	274	39.3	271	1.
20/80	37.6	259	37.	255	1.6
1/99	34.9	241	34.9	241	0.0
HFC-236fa/HFC-272ca
79.3/20.7	40.6	280	40.6	280	0.0
90/10	40.3	278	40.3	278	0.0
99/1	39.5	272	39.5	272	0.0
40/60	38.7	267	38.2	263	1.3
20/80	36.9	254	36.3	250	1.6
1/99	34.6	239	34.6	239	0.0
HFC-236fa/HFC-272ea
88.9/11.1	43.2	298	43.2	298	0.0
99/1	40.6	280	39.8	274	2.
60/40	39.6	273	34.6	239	12.6
65/35	40.6	280	36.9	254	9.1
64/36	40.4	279	36.4	251	9.9
HFC-236fa/HFC-281ea
62.5/37.5	54.	372	54.	372	0.0
80/20	52.8	364	51.7	356	2.1
90/10	49.7	343	46.5	321	6.4
95/5	46.2	319	42.6	294	7.8
99/1	41.2	284	39.9	275	3.2
40/60	52.8	364	52.2	360	1.1
20/80	50.4	347	49.4	341	2.
10/90	48.9	337	48.2	332	1.4
1/99	47.3	326	47.2	325	0.2
HFC-236fa/HFC-281fa
75.3/24.7	48.4	334	48.4	334	0.0
90/10	46.9	323	45.6	314	2.8
99/1	40.9	282	39.9	275	2.4
40/60	45.2	312	43.3	299	4.2
20/80	41.8	288	39.9	275	4.5
10/90	39.8	274	38.6	266	3.
1/99	37.9	261	37.8	261	0.3

The results of this Example show that these compositions are azeotropic or azeotrope-like because when 50 wt.% of an original composition is removed, the vapor pressure of the remaining composition is within about 10% of the vapor pressure of the original composition, at a temperature of 25°C.

EXAMPLE 3 Impact of Vapor Leakage at -25°C

A leak test is performed on compositions of HFC-236fa and HFC-272ea, at the temperature of -25°C. The results are summarized below.

WT%A/WT%B	INITIAL		50% LEAK		DELTA %P
	PSIA	KPA	PSIA	KPA
HFC-236fa/HFC-272ea
87.9/12.1	5.68	39.2	5.68	39.2	0.0
99/1	5.27	36.3	5.05	34.8	4.2
64/36	5.34	36.8	4.84	33.4	9.4
63/37	5.32	36.7	4.78	33.0	10.2

These results show that compositions of HFC-236fa and HFC-272ea are azeotropic or azeotrope-like at different temperatures, but that the weight percents of the components vary as the temperature is changed.

EXAMPLE 4 Refrigerant Performance

The following table shows the performance of various refrigerants. The data are based on the following conditions.

Evaporator temperature	48.0°F (8.9°C)
Condenser temperature	115.0°F (46.1°C)
Subcooled	12.0°F (6.7°C)
Return gas	65.0°F (18.3°C)
Compressor efficiency is 75%.

The refrigeration capacity is based on a compressor with a fixed displacement of 3.5 cubic feet per minute and 75% volumetric efficiency. 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 compressor work. It is a measure of refrigerant energy efficiency.

Refrig. Comp.	Evap. Press. Psia (kPa)	Cond. Press. Psia (kPa)	Comp. Dis. Temp. °F (°C)	COP	Capacity BTU/min (kw)
CFC-11	8(55)	30(207)	167(75)	5.10	50(0.9)
HCFC-22	95(655)	258(1779)	183(84)	4.60	397(7.0)
HFC-236ca/HFC-236fa
1.0/99.0	21(145)	69(476)	129(54)	4.71	103(1.8)
7.6/92.4	21(145)	69(476)	129(54)	4.71	102(1.8)
95.0/5.0	14(97)	50(345)	134(57)	4.85	77(1.4)
HFC-236ca/HFC-245eb
1.0/99.0	9(62)	34(234)	139(59)	4.95	53(0.9)
9.1/90.9	9(62)	35(241)	138(59)	4.95	54(1.0)
95.0/5.0	14(97)	48(331)	134(57)	4.85	73(1.3)
HFC-236ca/HFC-245fa
5.0/95.0	12(83)	43(296)	137(58)	4.9	66(1.2)
98.3/1.7	14(97)	48(331)	134(57)	4.85	74(1.3)
99.0/1.0	14(97)	49(338)	134(57)	4.85	74(1.3)
HFC-236ca/HFC-254eb
5.0/95.0	20(138)	64(441)	137(58)	4.85	100(1.8)
77.4/22.6	15(103)	53(365)	135(57)	4.86	81(1.4)
95.0/5.0	14(97)	50(345)	134(57)	4.84	76(1.3)
HFC-236ca/HFC-263ca
5.0/95.0	10(69)	36(248)	143(62)	4.99	57(1.0)
35.4/64.6	11(76)	39(269)	141(61)	4.96	62(1.1)
95.0/5.0	14(97)	48(331)	135(57)	4.85	73(1.3)
HFC-236ca/HFC-263fb
5.0/95.0	31(214)	95(655)	137(58)	4.76	145(2.6)
13.7/86.3	30(207)	91(627)	137(58)	4.77	139(2.4)
95.0/5.0	15(103)	51(352)	134(57)	4.87	79(1.4)
HFC-236ca/HFC-272ca
5.0/95.0	20(138)	63(434)	142(61)	4.92	100(1.8)
46.8/53.2	18(124)	59(407)	139(59)	4.96	94(1.7)
95.0/5.0	14(97)	50(345)	135(57)	4.85	77(1.4)
HFC-236ca/HFC-272fb
5.0/95.0	15(103)	51(352)	148(64)	4.99	81(1.4)
56.1/43.9	15(103)	52(359)	141(61)	4.92	82(1.4)
95.0/5.0	14(97)	50(345)	135(57)	4.86	76(13)
HFC-236ca/HFC-281ea
5.0/95.0	28(193)	84(579)	147(64)	4.92	135(2.4)
163/83.7	27(186)	82(565)	146(63)	4.91	132(2.3)
95.0/5.0	15(103)	53(365)	135(57)	4.88	81(1.4)
HFC-236ca/HFC-356mmz
5.0/95.0	9(62)	34(234)	123(51)	4.78	50(0.9)
78.1/21.9	13(90)	45(310)	131(55)	4.83	69(1.2)
95.0/5.0	14(97)	48(331)	133(56)	4.84	73(1.3)
HFC-236cb/HFC-236ea
5.0/95.0	16(110)	56(386)	133(56)	4.81	85(1.5)
36.7/63.3	17(117)	58(400)	132(56)	4.79	88(1.5)
95.0/5.0	19(131)	63(434)	130(54)	4.74	95(1.7)
HFC-236cb/HFC-236fa
5.0/95.0	21(145)	69(476)	129(54)	4.71	103(1.8)
28.2/71.8	21(145)	67(462)	129(54)	4.71	100(1.8)
95.0/5.0	19(131)	64(441)	129(54)	4.74	95(1.7)
HFC-236cb/HFC-245fa
5.0/95.0	12(83)	43(296)	137(58)	4.9	67(1.2)
25.6/74.4	14(97)	47(324)	135(57)	4.89	73(13)
95.0/5.0	19(131)	62(427)	130(54)	4.74	94(1.7)
HFC-236cb/HFC-254cb
5.0/95.0	20(138)	64(441)	136(58)	4.85	99(1.7)
52.1/47.9	20(138)	64(441)	133(56)	4.8	98(1.7)
95.0/5.0	19(131)	64(441)	130(54)	4.75	96(1.7)
HFC-236cb/HFC-254eb
5.0/95.0	20(138)	65(448)	136(58)	4.85	101(1.8)
39.0/61.0	20(138)	65(448)	134(57)	4.81	100(1.8)
95.0/5.0	20(138)	64(441)	130(54)	4.75	96(1.7)
HFC-236cb/HFC-263fb
5.0/95.0	32(221)	96(662)	137(58)	4.76	146(2.6)
19.0/81.0	30(207)	93(641)	136(58)	4.76	141(2.5)
95.0/5.0	20(138)	66(455)	130(54)	4.75	99(1.7)
HFC-236cb/HFC-272ca
5.0/95.0	20(138)	63(434)	141(61)	4.93	101(1.8)
58.2/41.8	21(145)	66(455)	135(57)	4.84	102(1.8)
95.0/5.0	20(138)	64(441)	130(54)	4.75	97(1.7)
HFC-236cb/HFC-272fb
5.0/95.0	15(103)	51(352)	147(64)	5	83(1.5)
45.0/55.0	18(124)	59(407)	141(61)	4.91	92(1.6)
95.0/5.0	20(138)	64(441)	130(54)	4.76	96(1.7)
HFC-236cb/HFC-281ea
5.0/95.0	28(193)	85(586)	147(64)	4.92	136(2.4)
39.1/60.9	28(193)	84(579)	142(61)	4.87	133(2.3)
95.0/5.0	21(145)	67(462)	131(55)	4.76	102(1.8)
HFC-236cb/HFC-281fa
5.0/95.0	22(152)	70(483)	148(64)	4.94	112(2.0)
56.1/43.9	23(159)	73(503)	140(60)	4.86	114(2.0)
95.0/5.0	20(138)	66(455)	131(55)	4.76	100(1.8)
HFC-236ea/HFC-236fa
5.0/95.0	21(145)	69(476)	129(54)	4.71	102(1.8)
17.6/82.4	21(145)	67(462)	130(54)	4.74	100(1.8)
95.0/5.0	16(110)	56(386)	133(56)	4.8	85(1.5)
HFC-236ea/HFC-245cb
1.0/99.0	38(262)	111(765)	124(51)	4.55	159(2.8)
3.7/96.3	37(255)	109(752)	124(51)	4.56	157(2.8)
95.0/5.0	17(117)	58(400)	133(56)	4.82	88(1.5)
HFC-236ea/HFC-263fb
5.0/95.0	32(221)	96(662)	137(58)	4.76	146(2.6)
20.0/80.0	29(200)	91(627)	137(58)	4.78	138(2.4)
95.0/5.0	17(117)	58(400)	134(57)	4.82	89(1.6)
HFC-236ea/HFC-272ca
5.0/95.0	20(138)	63(434)	141(61)	4.93	101(1.8)
50.0/50.0	19(131)	61(421)	138(59)	4.89	97(1.7)
95.0/5.0	17(117)	57(393)	134(57)	4.82	86(1.5)
HFC-236ea/HFC-272fb
5.0/95.0	15(103)	51(352)	148(64)	4.98	82(1.4)
75.0/25.0	17(117)	56(386)	138(59)	4.87	88(1.5)
95.0/5.0	16(110)	56(386)	134(57)	4.82	86(1.5)
HFC-236ea/HFC-281ea
5.0/95.0	28(193)	85(586)	147(64)	4.91	135(2.4)
33.9/66.1	26(179)	81(558)	145(63)	4.89	128(2.3)
95.0/5.0	18(124)	59(407)	135(57)	4.84	91(1.6)
HFC-236ea/HFC-281fa
5.0/95.0	22(152)	70(483)	148(64)	4.95	112(2.0)
44.8/55.2	21(145)	69(476)	144(62)	4.91	109(1.9)
95.0/5.0	17(117)	58(400)	135(57)	4.83	89(1.6)
HFC-236fa/HFC-245ca
5.0/95.0	8(55)	30(207)	139(59)	5.0	47(0.8)
98.0/2.0	21(145)	68(469)	129(54)	4.71	101(1.8)
99.0/1.0	21(145)	69(476)	129(54)	4.71	102(1.8)
HFC-236fa/HFC-245eb
5.0/95.0	10(69)	35(241)	138(59)	4.96	55(1.0)
90.4/9.6	20(138)	65(448)	130(54)	4.75	97(1.7)
99.0/1.0	21(145)	69(476)	129(54)	4.71	103(1.8)
HFC-236fa/HFC-254ca
5.0/95.0	8(55)	29(200)	142(61)	5.05	46(0.8)
92.4/7.6	19(131)	64(441)	130(54)	4.75	96(1.7)
99.0/1.0	21(145)	69(476)	129(54)	4.71	102(1.8)
HFC-236fa/HFC-254cb
5.0/95.0	20(138)	64(441)	136(58)	4.85	100(1.8)
99.8/0.2	21(145)	69(476)	129(54)	4.71	103(1.8)
HFC-236fa/HFC-254eb
5.0/95.0	20(138)	65(448)	136(58)	4.84	101(1.8)
74.4/25.6	21(145)	69(476)	131(55)	4.75	104(1.8)
95.0/5.0	21(145)	69(476)	129(54)	4.72	103(1.8)
HFC-236fa/HFC-272ca
5.0/95.0	20(138)	64(441)	141(61)	4.92	102(1.8)
79.3/20.7	22(152)	70(483)	132(56)	4.78	106(1.9)
95.0/5.0	22(152)	70(483)	130(54)	4.73	104(1.8)
HFC-236fa/HFC-272ea
5.0/95.0	12(83)	41(283)	149(65)	5.05	67(1.2)
88.9/11.1	21(145)	67(462)	132(56)	4.76	101(1.8)
95.0/5.0	21(145)	68(469)	130(54)	4.73	102(1.8)
HFC-236fa/HFC-281ea
5.0/95.0	28(193)	85(586)	147(64)	4.92	136(2.4)
62.5/37.5	27(186)	84(579)	138(59)	4.82	130(2.3)
95.0/5.0	23(159)	73(503)	131(55)	4.73	109(1.9)
HFC-236fa/HFC-281fa
5.0/95.0	22(152)	70(483)	148(64)	4.95	113(2.0)
75.3/24.7	24(165)	76(524)	136(58)	4.79	116(2.0)
95.0/5.0	22(152)	72(496)	130(54)	4.73	107(1.9)

EXAMPLE 5

This Example is directed to measurements of the liquid/vapor equilibrium curves for the mixtures in Figures 1-35.

Turning to Figure 1, the upper curve represents the composition of the liquid, and the lower curve represents the composition of the vapor.

The data for the compositions of the liquid in Figure 1 are obtained as follows. A stainless steel cylinder is evacuated, and a weighed amount of HFC-236ca is added to the cylinder. The cylinder is cooled to reduce the vapor pressure of HFC-236ca, and then a weighed amount of HFC-236fa is added to the cylinder. The cylinder is agitated to mix the HFC-236ca and HFC-236fa, and then the cylinder is placed in a constant temperature bath until the temperature comes to equilibrium at 25°C, at which time the vapor pressure of the HFC-236ca and HFC-236fa in the cylinder is measured. Additional samples of liquid are measured the same way, and the results are plotted in Figure 1.

The curve which shows the composition of the vapor is calculated using an ideal gas equation of state.

Vapor/liquid equilibrium data are obtained in the same way for the mixtures shown in Figures 2-35.

The data in Figures 1, 3, 6-10, 12 and 15-35 show that at 25°C, there are ranges of compositions that have vapor pressures higher than the vapor pressures of the pure components of the composition at that same temperature. As stated earlier, the higher than expected pressures of these compositions may result in an unexpected increase in the refrigeration capacity or efficiency of those compositions when compared to the pure components of the compositions.

The data in Figures 2, 4-5, 11 and 13-14 show that at 25°C, there are ranges of compositions that have vapor pressures below the vapor pressures of the pure components of the composition at that same temperature. These minimum boiling compositions are useful in refrigeration, and may show an improved efficiency when compared to the pure components of the composition.

The novel compositions of this invention, including the azeotropic or azeotrope-like compositions, may be used to produce refrigeration by condensing the compositions and thereafter evaporating the condensate in the vicinity of a body to be cooled. The novel 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.

In addition to refrigeration applications, the novel constant boiling or substantially 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 power cycle working fluids.

ADDITIONAL COMPOUNDS

Other components, such as aliphatic hydrocarbons having a boiling point of -60 to + 60°C, hydrofluorocarbonalkanes having a boiling point of -60 to + 60°C, hydrofluoropropanes having a boiling point of between -60 to + 60°C, hydrocarbon esters having a boiling point between -60 to + 60°C, hydrochlorofluorocarbons having a boiling point between -60 to + 60°C, hydrofluorocarbons having a boiling point of -60 to + 60°C, hydrochlorocarbons having a boiling point between -60 to + 60°C, chlorocarbons and perfluorinated compounds, can be added to the azeotropic or azeotrope-like compositions described above without substantially changing the properties thereof, including the constant boiling behavior, of the compositions.

Additives such as lubricants, corrosion inhibitors, surfactants, stabilizers, dyes and other appropriate materials may be added to the novel compositions of the invention for a variety of purposes provides they do not have an adverse influence on the composition for its intended application. Preferred lubricants include esters having a molecular weight greater than 250.

Claims (7)

1. A refrigerant composition comprising 1,1,2,2,3,3-hexafluoropropane and 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,3-pentafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoropropane, 1,2,2-trifluoropropane, 1,1,1-trifluoropropane, 2,2-difluoropropane, 1,1-difluoropropane, 2-fluoropropane or (CF3)2CHCH3 ; 1,1,1,2,2,3-hexafluoropropane and 1,1,2,3,3,3-hexafluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,2,2-tetrafluoropropane, 1,1,1,2-tetrafluoropropane, 1,1,1-trifluoropropane, 2,2-difluoropropane, 1,1-difluoropropane, 2-fluoropropane or 1-fluoropropane; 1,1,2,3,3,3-hexafluoro-propane and 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,2-pentafluoropropane, 1,1,1-trifluoro-propane, 2,2-difluoropropane, 1,1-difluoropropane, 2-fluoropropane or 1-fluoropropane; 1,1,1,3,3,3-bexafluoropropane and 1,1,2,2,3-pentafluoropropane, 1,1,1,2,3-pentafluoropropane, 1,2,2,3-tetrafluoropropane, 1,1,2,2-tetrafluoropropane, 1,1,1,2-tetrafluoropropane, 2,2-difluoropropane, 1,2-difluoropropane, 2-fluoropropane or 1-fluoropropane.
2. An azeotropic or azeotrope-like composition comprising: 1-99 weight percent 1,1,2,2,3,3-hexafluoropropane and 1-99 weight percent 1,1,1,3,3,3-hexafluoro-propane; 1-99 weight percent 1,1,2,2,3,3-hexafluoropropane and 1-99 weight percent 1,1,1,2,3-pentafluoropropane; 1-99 weight percent 1,1,2,2,3,3-hexafluoropropane and 1-99 weight percent 1,1,1,3,3-pentafluoropropane; 1-99 weight percent 1,1,2,2,3,3-hexafluoropropane and 1-99 weight percent 1,1,1 ,2-tetrafluoropropane; 1-99 weight percent 1,1,2,2,3,3-hexafluoropropane and 1-99 weight percent 1,2,2-trifluoro-propane; 1-62 weight percent 1,1,2,2,3,3-hexafluoropropane and 38-99 weight percent 1,1,1-trifluoropropane; 1-81 weight percent 1,1,2,2,3,3-hexafluoropropane and 19-99 weight percent 2,2-difluoropropane; 1-99 weight percent 1,1,2,2,3,3-hexa-fluoropropane and 1-99 weight percent 1,1-difluoropropane; 1-78 weight percent 1,1,2,3,3-hexafluoropropane and 22-99 weight percent 2-fluoropropane; 1-99 weight percent 1,1,2,2,3,3-hexafluoro-propane and 1-99 weight percent (CF3)2CHCH3; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1,1,2,3,3,3-hexafluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1,1,1,3,3,3-hexafluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1,1,1,3,3-pentafluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1,1,2,2-tetrafluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1,1,1,2-tetrafluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1,1,1-trifluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexa-fluoropropane and 1-99 weight percent 2,2-difluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1,1-difluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 2-fluoropropane; 1-99 weight percent 1,1,1,2,2,3-hexafluoropropane and 1-99 weight percent 1-fluoropropane; 1-99 weight percent 1,1,2,3,3,3-hexafluoropropane and 1-99 weight percent 1,1,1,3,3,3-hexafluoro-propane; 145 weight percent 1,1,2,3,3,3-hexafluoropropane and 55-99 weight percent 1,1,1,2,2-pentafluoropropane; 1-65 weight percent 1,1,2,3,3,3-hexafluoropropane and 35-99 weight percent 1,1,1-trifluoropropane; 1-99 weight percent 1,1,2,3,3,3-hexa-fluoropropane and 1-99 weight percent 2,2-difluoropropane; 1-99 weight percent 1,1,2,3,3,3-hexafluoro-propane and 1-99 weight percent 1,1-difluoropropane; 1-87 weight percent 1,1,2,3,3,3-hexafluoropropane and 13-99 weight percent 2-fluoropropane; 1-99 weight percent 1,1,2,3,3,3-hexafluoropropane and 1-99 weight percent 1-fluoropropane; 72-99 weight percent 1,1,1,3,3,3-hexafluoropropane and 1-28 weight percent 1,1,2,2,3-pentafluoropropane; 60-99 weight percent 1,1,1,3,3,3 -hexafluoropropane and 140 weight percent 1,1,1,2,3-pentafluoropropane; 68-99 weight percent 1,1,1,3,3,3-hexafluoropropane and 1-32 weight percent 1,2,2,3-tetra-fluoropropane; 1-99.8 weight percent 1,1,1,3,3,3-hexafluoropropane and 0.2-99 weight percent 1,1,2,2-tetrafluoropropane; 1-99 weight percent 1,1,1,3,3,3-hexafluoropropane and 1-99 weight percent 1,1,1,2-tetrafluoropropane; 1-99 weight percent 1,1,1,3,3,3-hexafluoropropane and 1-99 weight percent 2,2-difluoropropane; 64-99 weight percent 1,1,1,3,3,3-hexafluoropropane and 1-36 weight percent 1,2-difluoropropane; 1-99 weight percent 1,1,1,3,3,3-hexa-fluoropropane and 1-99 weight percent 2-fluoropropane; or 1-99 weight percent 1,1,1,3,3,3-hexa-fluoropropane and 1-99 weight percent 1-fluoropropane.
3. A process for producing refrigeration, comprising condensing a composition of Claim 1 or 2 and thereafter evaporating said composition in the vicinity of a body to be cooled.
4. A process for producing heat comprising condensing a composition of Claim 1 or 2 in the vicinity of a body to be heated, and thereafter evaporating said composition.
5. Effective amounts of 1,1,2,2,3,3-hexafluoropropane and 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,3-pentafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,2-tetrafluoropropane, 1,2,2-trifluoropropane, 1,1,1-trifluoropropane, 2,2-difluoropropane, 1,1 -difluoropropane, 2-fluoropropane or (CF3)2CHCH3; 1,1,1,2,2,3-hexafluoropropane and 1,1,2,3,3,3-hexafluoropropane, 1,1,1.3,3,3-hexafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,2,2-tetrafluoropropane, 1,1,1,2-tetrafluoropropane, 1,1,1-trifluoropropane, 2,2-difluoropropane, 1,1-difluoropropane, 2-fluoropropane or 1-fluoropropane; 1,1,2,3,3,3-hexafluoropropane and 1,1,1,3,3,3-hexafluoropropane, 1,1,1,2,2-pentafluoropropane, 1,1,1-trifluoropropane, 2,2-difluoropropane, 1,1-difluoropropane, 2-fluoropropane or 1-fluoropropane; 1,1,1,3,3,3-hexafluoropropane and 1,1,2,2,3-pentafluoropropane, 1,1,1,2,3-pentafluoropropane, 1,2,2,3-tetrafluoropropane, 1,1,2,2-tetrafluoropropane, 1,1,1,2-tetrafluoropropane, 2,2-difluoropropane, 1,2-difluoropropane, 2-fluoropropane or 1-fluoropropane to form binary compositions having a maximum or minimum vapor pressure when compared to the vapor pressures of the components of the binary composition.
6. A process for producing refrigeration, comprising condensing a composition of Claim 5 and thereafter evaporating said composition in the vicinity of a body to be cooled.
7. A process for producing heat comprising condensing a composition of Claim 5 in the vicinity of a body to be heated, and thereafter evaporating said composition.