| PATENT ASSIGNEE'S COUNTRY | USA |
| UPDATE | 01.00 |
| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 11.01.00 |
| PATENT TITLE |
Azeotrope(like) compositions including a hexafluoropropane and butane |
| PATENT ABSTRACT |
Compositions disclosed include hexafluoropropane and a hydrocarbon having from 1 to 5 carbon atoms or dimethyl ether. These compositions are useful as refrigerants, 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. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | 21.04.97 |
| PATENT REFERENCES CITED | This data is not available for free |
| PATENT PARENT CASE TEXT | This data is not available for free |
| PATENT CLAIMS |
1. An azeotropic or azeotrope-like composition consisting essentially of, by weight, about 81% to about 37% of 1,1,2,2,3,3-hexafluoropropane (HFC 236ca) and about 19% to about 63% of n-butane (R 600), wherein the vapor pressure of said composition at about 25.degree. C. is about 51.0 psia to about 51.8 psia, and wherein the vapor pressure of said composition changes by less than about 10 percent after 50% of said composition has been evaporated at about 25.degree. C. 2. An azeotropic or azeotrope-like composition consisting essentially of, by weight, about 87% to about 41% of 1,1,1,2,2,3-hexafluoropropane (HFC 236cb) and about 13% to about 59% of n-butane (R 600), wherein the vapor pressure of said composition at about 25.degree. C. is about 50.1 psia to about 52.4 psia, and wherein the vapor pressure of said composition changes by less than about 10 percent after 50% of said composition has been evaporated at about 25.degree. C. 3. An azeotropic or azeotrope-like composition consisting essentially of, by weight, about 83% to about 39% of 1,1,2,3,3,3-hexafluoropropane (HFC 236ea) and about 17% to about 61% of n-butane (R 600), wherein the vapor pressure of said composition at about 25.degree. C. is about 52.7 psia to about 54.0 psia, and wherein the vapor pressure of said composition changes by less than about 10 percent after 50% of said composition has been evaporated at about 25.degree. C. 4. An azeotropic or azeotrope-like composition consisting essentially of, by weight, about 90% to about 50% of 1,1,1,3,3,3-hexafluoropropane (HFC 236fa) and about 10% to about 50% of n-butane (R 600), wherein the vapor pressure of said composition at about 25.degree. C. is about 56.0 psia to about 57.9 psia, and wherein the vapor pressure of said composition changes by less than about 10 percent after 50% of said composition has been evaporated at about 25.degree. C. 5. A process for producing refrigeration, comprising condensing a composition of claim 1 and thereafter evaporating said composition in the vicinity of the body to be cooled. 6. A process for producing refrigeration, comprising condensing a composition of claim 2 and thereafter evaporating said composition in the vicinity of the body to be cooled. 7. A process for producing refrigeration, comprising condensing a composition of claim 3 and thereafter evaporating said composition in the vicinity of the body to be cooled. 8. A process for producing refrigeration, comprising condensing a composition of claim 4 and thereafter evaporating said composition in the vicinity of the body to be cooled. 9. A process for producing heat comprising condensing a composition of claim 1 in the vicinity of a body to be heated, and thereafter evaporating said composition. 10. A process for producing heat comprising condensing a composition claim 2 in the vicinity of a body to be heated, and thereafter evaporating said composition. 11. A process for producing heat comprising condensing a composition claim 3 in the vicinity of a body to be heated, and thereafter evaporating said composition. 12. A process for producing heat comprising condensing a composition of claim 4 in the vicinity of a body to be heated, and thereafter evaporating said composition. 13. A process of preparing a thermoset or thermoplastic foam comprising the step of foaming a mixture of the composition of claim 1 and a thermoset or thermoplastic material. 14. A process of preparing a thermoset or thermoplastic foam comprising the step of foaming a mixture of the composition of claim 2 and a thermoset or thermoplastic material. 15. A process of preparing a thermoset or thermoplastic foam comprising the step of foaming a mixture of the composition of claim 3 and a thermoset or thermoplastic material. 16. A process of preparing a thermoset or thermoplastic foam comprising the step of foaming a mixture of the composition of claim 4 and a thermoset or thermoplastic material. 17. A process for cleaning a solid surface comprising treating said surface with the composition of claim 1. 18. A process for cleaning a solid surface comprising treating said surface with the composition of claim 2. 19. A process for cleaning a solid surface comprising treating said surface with the composition of claim 3. 20. A process for cleaning a solid surface comprising treating said surface with on of claim 4. |
| PATENT DESCRIPTION |
FIELD OF THE INVENTION This invention relates to refrigerant compositions that include a hydrofluorocarbon as a component. These compositions are useful as refrigerants, cleaning agents, expansion agents for polyolefins and polyarethanes, 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 cleaning agents or solvents 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 compositions of hexafluoropropane and a hydrocarbon having from 1 to 5 carbon atoms or dimethyl ether. Examples of hydrocarbons having from 1 to 5 carbon atoms include butane, cyclopropane, isobutane, propane. Examples of the inventive compositions include compositions of 1,1,2,2,3,3-hexafluoropropane (HFC-236ca) and butane, cyclopropane, isobutane or propane; 1,1,1,2,2,3-hexafluoropropane (HFC-236cb) and butane, cyclopropane, dimethyl ether (DME), isobutane or propane; 1,1,2,3,3,3-hexafluoropropane (HFC-236ea) and butane, cyclopropane, DME, isobutane or propane; and 1,1,1,3,3,3-hexafluoropropane (HFC-236fa) and DME, butane, cyclopropane, isobutane or propane. These compositions are also useful as clean ng 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 1,1,2,2,3,3-hexafluoropropane and butane, cyclopropane, isobutane or propane; 1,1,1,2,2,3-hexafluoropropane and butane, cyclopropane, DME, isobutane or propane; 1,1,2,3,3,3-hexafluoropropane and butane, cyclopropane, DME, isobutane or propane; and 1,1,1,3,3,3-hexafluoropropane and DME, butane, cyclopropane, isobutane or propane to form an azeotropic or azeotrope-like composition. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph of the vapor pressure of liquid mixtures of HFC-236ca and butane at 25.degree. C.; FIG. 2 is a graph of the vapor pressure of liquid mixtures of HFC-236ca and cyclopropane at 25.degree. C.; and FIG. 3 is a graph of the vapor pressure of liquid mixtures of HFC-236ca and isobutane at 25.degree. C.; FIG. 4 is a graph of the vapor pressure of liquid mixtures of HFC-236ca and propane at 25.degree. C.; FIG. 5 is a graph of the vapor pressure of liquid mixtures of HFC-236cb and butane at 25.degree. C.; FIG. 6 is a graph of the vapor pressure of liquid mixtures of HFC-236cb and cyclopropane at 25.degree. C.; FIG. 7 is a graph of the vapor pressure of liquid mixtures of HFC-236cb and DME at 25.degree. C.; FIG. 8 is a graph of the vapor pressure of liquid mixtures of HFC-236cb and isobutane at 25.degree. C.; FIG. 9 is a graph of the vapor pressure of liquid mixtures of HFC-236cb and propane at 25.degree. C.; FIG. 10 is a graph of the vapor pressure of liquid mixtures of HFC-236ea and butane at 25.degree. C.; FIG. 11 is a graph of the vapor pressure of liquid mixtures of HFC-236ea and cyclopropane at 25.degree. C.; FIG. 12 is a graph of the vapor pressure of liquid mixtures of HFC-236ea and DME at 0.degree. C.; FIG. 13 is a graph of the vapor pressure of liquid mixtures of HFC-236ea and isobutane at 25.degree. C.; FIG. 14 is a graph of the vapor pressure of liquid mixtures of HFC-236ea and propane at 25.degree. C.; FIG. 15 is a graph of the vapor pressure of liquid mixtures of BFC-236fa and butane at 0.degree. C.; FIG. 16 is a graph of the vapor pressure of liquid mixtures of HFC-236fa and cyclopropane at 25.degree. C.; FIG. 17 is a graph of the vapor pressure of liquid mixtures of HFC-236fa and isobutane at 0.degree. C.; FIG. 18 is a graph of the vapor pressure of liquid mixtures of HFC-236fa and propane at 25.degree. C.; and FIG. 19 is a graph of the vapor pressure of liquid mixtures of HFC-236fa and DME at 3.degree. C. DETAILED DESCRIPTION The present invention relates to compositions of hexafluoropropane and a hydrocarbon having from 1 to 5 carbon atoms or DME. Examples of hydrocarbons having from 1 to 5 carbon atoms include butane, cyclopropane, isobutane, propane, cyclopentane, isopentane and n-pentane. Examples of the inventive compositions include compositions of 1,1,2,2,3,3-hexafluoropropane and butane, cyclopropane, isobutane or propane; 1,1,1,2,2,3-hexafluoropropane and butane, cyclopropane, DME, isobutane or propane; 1,1,2,3,3,3-hexafluoropropane and butane, cyclopropane, DME, isobutane or propane; and 1,1,1,3,3,3-hexafluoropropane and DME, butane, cyclopropane, isobutane or propane. The present invention also relates to the discovery of azeotropic or azeotrope-like compositions of effective amounts of compositions of hexafluoropropane and butane, cyclopropane, isobutane, propane or DME, including compositions of 1,1,2,2,3,3-hexafluoropropane and butane, cyclopropane, isobutane or propane; 1,1,1,2,2,3-hexafluoropropane and butane, cyclopropane, DME, isobutane or propane; 1,1,2,3,3,3-hexafluoropropane and butane, cyclopropane, DME, isobutane or propane; and 1,1,1,3,3,3-hexafluoropropane and DME, butane, cyclopropane, isobutane or propane to form an azeotropic or azeotrope-like composition. 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. Another way to characterize an azeotrope-like composition is that the bubble point vapor pressure and the dew point vapor pressure of the composition at a particular temperature are substantially the same. 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 1,1,2,2,3,3-hexafluoropropane and butane, cyclopropane, isobutane or propane; 1,1,1,2,2,3-hexafluoropropane and butane, cyclopropane, DME, isobutane or propane; 1,1,2,3,3,3-hexafluoropropane and butane, DME, cyclopropane, isobutane or propane; and 1,1,1,3,3,3-hexafluoropropane and DME, butane, cyclopropane, isobutane or propane 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 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 lower at a particular temperature 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 higher at a particular temperature 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 are substantially constant boiling. 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 are substantially constant boiling according to the change in vapor pressure of the composition when 50 weight percent 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. |
| PATENT EXAMPLES | This data is not available for free |
| PATENT PHOTOCOPY | Available on request |
|
Want more information ? Interested in the hidden information ? Click here and do your request. |