Compositions containing difluoromethane and fluorine-substituted olefins

Abstract

To provide a composition that is potentially useful in many applications including vapor compression heating and cooling systems and methods, and at the same time has heat transfer properties, chemical stability, low or no toxicity, low or no flammability, compatibility with lubricants, and the like, and avoids disadvantages.SOLUTION: Compositions comprising polyfluorinated olefins and HFC-32 are disclosed. In highly preferred embodiments, difluoromethane (R-32) and 11133 - tetrafluoropropene (HFO - 1234ze, including all isomers) and / or 1112 - tetrafluoropropene (HFO - 1234yf) and / or 12333 - pentafluoropropene (HFO - 1225ye) are included and used in the present methods. Such compositions are particularly useful in stationary refrigerators and air conditioners.SELECTED DRAWING: None

Description

[Technical Field]

[0001] Related Applications This application is related (as a continuation-in-part) to and claims the benefit of priority to International Application No. PCT / US2008 / 069139, filed July 3, 2008, which claims the benefit of priority to International Application No. PCT / US2008 / 069139, filed July 6, 2007. This application also claims the benefit of priority to Provisional Application No. 60 / 693853, filed June 24, 2005, and is related (as a continuation-in-part) to and claims the benefit of priority to co-pending U.S. application No. 11 / 475,605, filed June 26, 2006, which is related as a continuation-in-part to each of the following regular U.S. applications: 10 / 694,273; 10 / 695,212; and 10 / 694,272, each filed October 27, 2003. This application is also related to and claims the benefit of the following U.S. applications: 11 / 385,259, filed March 20, 2006, currently pending, which claims the benefit of 10 / 695,212, filed October 23, 2003, now abandoned; and 11 / 757,782, filed June 4, 2006, currently pending, which claims the benefit of priority to 10 / 694,272, filed October 27, 2003. This application is also related to and claims the benefit of the following U.S. provisional applications: 61 / 099,382, filed September 23, 2008, and 61 / 084,997, filed July 30, 2008. Each of the applications identified in this paragraph is incorporated herein by reference as if fully set forth below.

[0002] FIELD OF THE INVENTION The present invention relates to compositions, methods, and systems that have utility in numerous applications, including, inter alia, heat transfer systems such as refrigeration systems. In preferred aspects, the present invention is directed to refrigerant compositions comprising difluoromethane and at least one multifluorinated olefin and / or at least one fluoroiodocarbon, and the preferred use of such compositions in stationary refrigeration and air conditioning systems. [Background technology]

[0003] Fluorocarbon-based fluids have been widely used in many commercial and industrial applications, including as working fluids in multiple systems such as air conditioning systems, heat pump systems, and refrigeration systems, among other uses such as aerosol propellants, blowing agents, and gaseous dielectrics.

[0004] While commercially viable, heat transfer fluids must meet certain very specific, and in certain cases very stringent, combinations of physical, chemical, and economic properties. Furthermore, many different types of heat transfer systems and devices exist, and the heat transfer fluids used in such systems often must possess a specific set of properties to meet the needs of the particular system. For example, systems based on the vapor compression cycle typically involve the absorption of heat at a relatively low pressure to cause a phase change of a refrigerant from a liquid to a vapor phase, the compression of the vapor to a relatively high pressure, the removal of heat at this relatively high pressure and temperature to condense the vapor back to a liquid phase, and the reduction in pressure to begin the cycle again.

[0005] For example, certain fluorocarbons have been preferred components in many heat exchange fluids, such as refrigerants, for many years in many applications. Fluoroalkanes, such as chlorofluoromethane and chlorofluoroethane, have become widely used as refrigerants in several applications, including air conditioning and heat pump applications, due to their unique combination of chemical and physical properties, such as heat capacity, flammability, stability under operating conditions, and miscibility with lubricants, if any, used in the system. Additionally, fluoroalkanes are commonly used in vapor compression systems. Most refrigerants used in the industry are either single component fluids, zeotropic mixtures, or azeotropic mixtures. It is either an azeotropic mixture.

[0006] In recent years, there has been growing concern about potential damage to the Earth's atmosphere and climate, and certain chlorine-based compounds have been identified as particularly problematic in this regard. The use of chlorine-containing compositions (e.g., chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs)) as refrigerants in air conditioning and refrigeration systems has become unpopular due to the ozone depletion potential associated with many such compounds. Thus, there is a growing need for new fluorocarbon and hydrofluorocarbon compounds that provide alternatives for refrigeration and heat pump applications. For example, it has become desirable to upgrade chlorine-containing refrigeration systems by replacing them with non-chlorine-containing refrigerant compounds, such as hydrofluorocarbons (HFCs), that do not deplete the ozone layer.

[0007] Another concern surrounding many current refrigerants is the propensity of many such products to contribute to global warming. This characteristic is commonly measured as Global Warming Potential (GWP). The GWP of a compound is a measure of the chemical's potential contribution to the greenhouse effect relative to a known reference molecule, i.e., CO2, which has a GWP=1. For example, the following known refrigerants have the following Global Warming Potentials:

[0008] [Table 1]

[0009] While each of the above-mentioned refrigerants has proven effective in many respects, these materials have fallen out of favor because it is often undesirable to use materials with a GWP greater than about 1000. Thus, a need exists for replacements for these and other current refrigerants with undesirable GWPs.

[0010] There is thus an increasing need for new fluorocarbon and hydrofluorocarbon compounds and compositions that are attractive alternatives to compositions previously used in these and other applications. For example, it has become desirable to upgrade certain systems, including chlorine-containing and certain HFC-containing refrigerant systems, by replacing the current refrigerants with refrigerant compositions that do not deplete the ozone layer or contribute to unnecessary levels of global warming, while at the same time meeting all of the other stringent requirements of such systems for materials used as heat transfer media.

[0011] With respect to performance characteristics, applicants recognize that potential refrigerant replacements must also possess properties present in many of the most widely used fluids, such as excellent heat transfer properties, chemical stability, low or no toxicity, low or no flammability, and compatibility with lubricants, among others.

[0012] With regard to efficiency in use, it is important to note that loss of thermodynamic performance or energy efficiency of a refrigerant can have secondary environmental impacts through increased fossil fuel use resulting from high demand for electrical energy.

[0013] Furthermore, it is generally believed desirable that refrigerant substitutions be effective without significant industry changes to conventional vapor compression technology currently used with current refrigerants, such as CFC-containing refrigerants.

[0014] Applicants have thus come to recognize a need for compositions, particularly heat transfer compositions, that are potentially useful in numerous applications, including vapor compression heating and cooling systems and processes, while avoiding one or more of the disadvantages previously described.

[0015] Applicants have also come to recognize that lubricant compatibility is particularly important in many applications. More specifically, it is highly desirable for refrigeration fluids to be compatible with the lubricants utilized in the compressor units used in most refrigeration systems. Unfortunately, many chlorine-free refrigeration fluids, including HFCs, are relatively insoluble and / or immiscible in the types of lubricants traditionally used with CFCs and HFCs, including, for example, mineral oil, alkylbenzenes, or poly(alpha-olefins). For a refrigeration fluid-lubricant combination to perform at a desired level of efficiency in a compression refrigeration, air conditioning, and / or heat pump system, the lubricant should be sufficiently soluble in the refrigerating fluid over a wide range of operating temperatures. Such solubility reduces the viscosity of the lubricant, allowing it to flow more easily throughout the system. Without such solubility, the lubricant would tend to remain in the evaporator coils of a refrigeration, air conditioning, or heat pump system, as well as other parts of these systems, thereby reducing system performance.

[0016] Flammability is another important characteristic for many applications. That is, the use of compositions that are non-flammable or have relatively low flammability is important or considered essential in many applications, particularly heat transfer applications. As used herein, the term "non-flammable" refers to a compound or composition that is non-flammable as measured in accordance with ASTM Standard E-681, dated 2002, which is incorporated herein by reference. Unfortunately, many HFCs desirable for use in refrigerant compositions are not non-flammable. For example, the fluoroalkane difluoroethane (HFC-152a) and the fluoroalkene 1,1,1-trifluoropropene (HFO-1243zf) are each flammable and therefore cannot be used alone in many applications.

[0017] Higher fluoroalkenes, i.e., fluorine-substituted alkenes having at least five carbon atoms, have been proposed for use as refrigerants. U.S. Patent No. 4,788,352 to Smutny is directed to the production of fluorinated C5-C8 compounds having at least some degree of unsaturation. The Smutny patent identifies such higher olefins as known to have utility as refrigerants, pesticides, dielectric fluids, heat transfer fluids, solvents, and intermediates in various chemical reactions. (See column 1, lines 11-22.) While the fluorinated olefins described in Smutny may have some level of effectiveness in heat transfer applications, it is believed that such compounds may also have certain disadvantages. For example, some of these compounds tend to attack substrates, particularly general-purpose plastics such as acrylics and ABS resins. Moreover, the higher olefin compounds described in Smutny may also be undesirable in certain applications due to the potential level of toxicity of such compounds, which may result from the pesticide activity noted in Smutny. Also, such compounds may have boiling points that are too high to make them useful as refrigerants in certain applications. Summary of the Invention

[0018] In accordance with one aspect of the present invention, the inventors have discovered that one or more of the above-noted needs, and potentially other needs, can be met by compositions, preferably heat transfer compositions, and even more preferably heat transfer compositions and systems, comprising, and in certain preferred embodiments consisting essentially of, difluoromethane (R-32) and at least one second component selected from C2-C5 polyfluorinated olefins, preferably at least one C3-C5 tetra- or penta-fluorinated olefin, and even more preferably at least one tetrafluoropropene. In highly preferred embodiments of this aspect of the invention, the at least one C3-C5 polyfluorinated olefin comprises, and in certain embodiments consists essentially of, one or more compounds having a -CF3 end group and an unsaturated terminal carbon having no more than one fluorine substituent. In highly preferred embodiments, the compositions comprise, and the methods employ, difluoromethane (R-32) and 1,1,1,3,3-tetrafluoropropene (HFO-1234ze, including all isomers) and / or 1,1,1,2-tetrafluoropropene (HFO-1234yf) and / or 1,2,3,3,3-pentafluoropropene (HFO-1225ye).

[0019] For embodiments of the invention in which the polyfluorinated compound has at least one Br substituent, it is preferred that the compound does not contain hydrogen. In such embodiments, it is also generally preferred that the Br substituent be on an unsaturated carbon, and more preferably that the Br substituent be on a non-terminal unsaturated carbon. One embodiment of this class is CF3CBr=CF2, including all of its isomers.

[0020] In certain embodiments, the composition further comprises a third component selected from at least a fluorinated C2-C3 alkane, CF3I, and combinations thereof. As used herein, the term "fluorinated C2-C3 alkane" means an alkane having two or three carbon atoms and at least one fluorine substituent. In certain preferred embodiments of this aspect of the invention, the second and / or third component acts as a flammability reducer. As used herein, the term "flammability reducer" refers to a compound or combination of compounds that has the net effect of reducing the flammability of the composition relative to the flammability of difluoromethane alone. In certain preferred embodiments, the third component is selected from the group consisting of fluorinated ethanes.

[0021] The term "HFO-1234" is used herein to refer to all tetrafluoropropenes. Included among the tetrafluoropropenes are 1,1,1,2-tetrafluoropropene (HFO-1234yf) and both cis- and trans-1,1,1,3-tetrafluoropropene (HFO-1234ze). The term "HFO-1234ze" is used herein to generally refer to 1,1,1,3-tetrafluoropropene, regardless of whether it is the cis- or trans-form. The terms "cisHFO-1234ze" and "transHFO-1234ze" are used herein to refer to the cis- and trans-forms of 1,1,1,3-tetrafluoropropene, respectively. Thus, the term "HFO-1234ze" includes within its scope cisHFO-1234ze, transHFO-1234ze, and all combinations and mixtures thereof.

[0022] The present invention also provides methods and systems utilizing the compositions of the present invention, including methods and systems for transferring heat, methods and systems for replacing existing heat transfer fluids in existing heat transfer systems, and methods for selecting a heat transfer fluid in accordance with the present invention to replace one or more existing heat transfer fluids. In a preferred embodiment, a method for selecting a heat transfer fluid substitute is provided. The method and system involves replacing one or more of the following heat transfer fluids in current heat transfer systems: R-22, R-134a, R-404A, R-407C, R-410A, R-507, and combinations of any two or more of these. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 shows ternary composition curves and also binary compositions for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants, as described in the Examples herein. [Figure 2] FIG. 2 shows the ternary composition curves and also the binary compositions for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 3] FIG. 3 shows the ternary composition curves and also the binary compositions for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 4] FIG. 4 shows the ternary composition curves and also the binary compositions for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 5] FIG. 5 shows the ternary composition curves and also the binary compositions for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 6]FIG. 6 shows the ternary composition curves and also the binary compositions for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 7] FIG. 7 shows the ternary composition curves and also the binary compositions for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 8] FIG. 8 shows the ternary composition curves and also the binary composition curves for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 9] FIG. 9 shows the ternary composition curves and also the binary composition curves for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 10] FIG. 10 shows the ternary composition curves and also the binary composition curves for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 11] FIG. 11 shows the ternary composition curves and also the binary composition curves for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. [Figure 12] FIG. 12 shows the ternary composition curves and also the binary composition curves for certain preferred compositions of the present invention at various concentrations of each component whose performance is substantially comparable to known refrigerants as described in the Examples herein. DETAILED DESCRIPTION OF THE INVENTION

[0024] composition One benefit of certain embodiments of the present invention is that they provide compositions that have exceptional flammability characteristics while maintaining other important properties within desired ranges. Applicants recognize that both R-32 and HFO-1234yf have reasonable flame limits at room temperature. However, applicants note that the combustion hazard of the compounds in the present compositions compares favorably to other HFCs, such as R-152a, and other HCs, such as R-290. One way to characterize the flammability of these materials is to measure the burning rate of each compound. The maximum burning velocities of R-32, R-152a, and R-290 are reported to be 6.7, 23.0, and 38.5 cm / s, respectively (Jabbour). The burning velocity of R-32 and HFO-1234ze(E) has been measured at 1.5 cm / s. Burning velocity measurements are designed to be performed at room temperature. Because HFO-1234ze(E) is non-flammable at room temperature, its burning velocity cannot be directly compared to other values. However, it is reasonable to expect that the burning velocity of HFO-1234ze(E) will be lower than that of HFO-1234yf. This would mean that all mixtures of R-32 and HFO-1234ze and / or HFO-1234yf will have burning velocities lower than 6.7 cm / s. When comparing different materials, if a first material has a lower burning velocity than a second material, then the first material has a lower likelihood of stable flame propagation compared to the second material.

[0025] In a preferred embodiment, the at least one polyfluorinated olefin compound of the composition of the present invention comprises a compound of Formula I:

[0026] [ka]

[0027] wherein each R is independently Cl, F, Br, I, or H; R' is (CR2) n Y, Y is CRF2, and n is 0, 1, 2, or 3, although it is generally preferred that when Br is present in the compound, there be no hydrogen in the compound. In certain embodiments, Br is absent from the compound.

[0028] In a highly preferred embodiment, Y is CF3, n is 0 or 1 (most preferably 0), at least one of the remaining R, including R in R', is F, and preferably R is not Br, or if Br is present, there are no hydrogens present in the compound.

[0029] Applicants generally believe that compounds of Formula I, as described above, are generally effective and useful in heat transfer compositions, and refrigerant compositions, in particular. The compositions of the present invention also find use as blowing agent compositions, compatibilizers, aerosols, propellants, fragrances, flavoring compounds, solvent compositions, and expansion agent compositions. However, Applicants have surprisingly and unexpectedly discovered that certain compounds having a structure according to the above formula exhibit highly desirable low levels of toxicity compared to other such compounds. As can be readily appreciated, this discovery potentially has numerous advantages and benefits with respect to the formulation of not only refrigerant compositions, but also any and all compositions containing relatively toxic compounds satisfying the above formula. More specifically, Applicants believe that compounds with relatively low levels of toxicity are associated with compounds of Formula II, preferably those in which Y is CF3, n is 0 or 1, and at least one R on the unsaturated terminal carbon and at least one of the remaining R is F or Cl. Applicants also believe that all structural, geometric and optical isomers of such compounds are effective and advantageously of low toxicity.

[0030] In certain preferred embodiments, the polyfluorinated compounds of the present invention include C3 or C4 hydrofluorochloroolefins (HCFOs), preferably C3 HCFOs, more preferably compounds according to Formula I, where Y is CF3, n is 0, at least one R on the unsaturated terminal carbon is H, and at least one of the remaining R is Cl. HCFO-1233 is an example of such a preferred compound.

[0031] In highly preferred embodiments, particularly those involving the low-toxicity compounds described above, n is zero. In certain highly preferred embodiments, the compositions of the present invention comprise one or more tetrafluoropropenes, including HFO-1234yf, (cis)HFO-1234ze, (trans)HFO-1234ze, and combinations of two or more of these. While the properties of (cis)HFO-1234ze and (trans)HFO-1234ze differ in at least some respects, each of these compounds is believed to be suitable for use alone or together with other compounds, including its optical isomers, for each of the applications, methods, and systems described herein. For example, (trans)HFO-1234ze is preferred for use in certain systems due to its relatively low boiling point (-19°C), while (cis)HFO-1234ze has a boiling point of +9°C and is preferred for use in other applications. Of course, combinations of cis- and trans-isomers may be acceptable and / or preferred in many embodiments. Thus, it should be understood that the terms "HFO-1234ze" and 1,3,3,3-tetrafluoropropene refer to either or both optical isomers, and that, unless otherwise indicated, by use of the term, it is intended that each of the cis- and trans-forms is applicable and / or useful for the stated purpose.

[0032] The compound HFO-1234 is a known material and is listed in the Chemical Abstracts database. It is used to catalytically oxidize various saturated and unsaturated halogen-containing C3 compounds. The production of fluoropropenes such as CF3CH=CH2 by in-phase fluorination is described in U.S. Patent Nos. 2,889,379; 4,798,818; and 4,465,786, each of which is incorporated herein by reference. EP 974,571, also incorporated herein by reference, describes the production of 1,1,1,3,3-pentafluoropropane (H and discloses the preparation of 1,1,1,3-tetrafluoropropene by contacting 1,1,1,3-tetrafluoropropene (FC-245fa) with a chromium-based catalyst in the vapor phase at elevated temperatures, or with an alcoholic solution of KOH, NaOH, Ca(OH)2, or Mg(OH)2 in the liquid phase. Additionally, methods for producing compounds according to the present invention are generally described in pending U.S. patent application entitled "Process for Producing Fluoropropenes," attorney docket number (H0003789(26267)), which is also incorporated herein by reference.

[0033] Other preferred compounds for use in accordance with the present invention include pentafluoropropene, including all its isomers (e.g., HFO-1225), and tetra- and pentafluorobutene, including all its isomers (e.g., HFO-1354 and HFO-1345). Of course, the compositions of the present invention may include combinations of any two or more compounds within the broad scope of the present invention, or within any of the preferred ranges of the present invention.

[0034] The present compositions, particularly those containing HFO-1234 (including HFO-1234ze and HFO-1234yf), are believed to have advantageous properties for a number of important reasons. For example, Applicant believes, based at least in part on mathematical modeling, that the fluoroolefins of the present invention have no substantial adverse effect on atmospheric chemistry and contribute negligibly to ozone depletion compared to some other halogenated species. Thus, preferred compositions of the present invention have the advantage of not contributing substantially to ozone depletion. Additionally, preferred compositions do not contribute substantially to global warming compared to many of the hydrofluoroalkanes currently in use.

[0035] Other compounds and / or ingredients that modify certain properties of the composition (e.g., cost, etc.) may also be used. All such compounds and ingredients that may be included in the compositions of the present invention are within the broad scope of the present invention.

[0036] In certain preferred embodiments, the compositions of the present invention have a global warming potential (GWP) of about 1000 or less, more preferably about 500 or less, and even more preferably about 150 or less. In certain embodiments, the GWP of the compositions is about 100 or less, and even more preferably about 75 or less. As used herein, "GWP" is measured relative to carbon dioxide over a 100-year period, as defined in "The Scientific Assessment of Ozone Depletion, 2002, a report of the World Meteorological Association's Global Ozone Research and Monitoring Project," which is incorporated herein by reference.

[0037] In certain preferred embodiments, the compositions of the present invention also preferably have an Ozone Depletion Potential (ODP) of 0.05 or less, more preferably 0.02 or less, and even more preferably about 0. As used herein, "ODP" is as defined in "The Scientific Assessment of Ozone Depletion, 2002, A report of the World Meteorological Association's Global Ozone Research and Monitoring Project," which is incorporated herein by reference.

[0038] The amount of polyfluorinated olefin, particularly the compound of Formula I, and even more particularly the HF-1234yf compound, contained in the present compositions can vary widely depending on the particular application, with compositions containing more than trace amounts up to less than 100% of the compound being within the broad scope of the present invention. Moreover, the present compositions can be azeotropic, azeotrope-like, or non-azeotropic. In preferred embodiments, the present compositions contain the compound of Formula I, preferably HFO-1234, more preferably HFO-1234ze and / or HFO-1234yf, in an amount of about 5% to about 99% by weight, and even more preferably about 5% to about 95% by weight. Many additional compounds or components, including lubricants, stabilizers, metal passivators, corrosion inhibitors, flame retardants, and other compounds and / or components that adjust certain properties of the composition (e.g., cost, etc.), may be included in the present compositions, and the presence of all such compounds and components is within the broad scope of the present invention.

[0039] It is contemplated that the amount of HFC-32 present may vary widely within the broad scope of the present invention. In preferred embodiments, the amount of HFC-32 present in the composition is selected based on the desired heat transfer capacity of the fluid, typically based on the system in which the fluid will be used or in which it will reside. For embodiments in which the composition is used, or intended for use, in a system originally designed for use with two or more of R-22, R-134a, R-404A, R-407C, R-410A, and R-507 (hereinafter, for convenience and without limitation, referred to as the "current refrigerant group"), difluoromethane is preferably present in the composition in an amount of from about 1% to about 95% by weight, more preferably from about 1% to about 80% by weight, even more preferably from about 3% to about 75% by weight, and even more preferably from about 5% to about 70% by weight.

[0040] In certain preferred embodiments, the first component further comprises CO2, in addition to R-32, preferably in an amount of about 5% or less by weight of the composition. The second component of the present composition may also vary widely within the broad scope of the present invention. In preferred embodiments, the particular second component and its amount in the composition are selected based on its ability to reduce the flammability of the overall composition. For embodiments in which the composition is used, or intended to be used, in a system originally designed for use with one or more refrigerants in the current refrigerant family, the second component is preferably present in the composition in an amount of from about 5% to about 99% by weight of the composition. In other preferred embodiments, the second component is present in an amount of from about 20 to about 95 percent by weight of the composition.

[0041] For embodiments according to the second aspect having a third component, the amount of the third component may also vary within the broad scope of the present invention. In preferred embodiments, the amount of the third component present in the composition is selected based on the desired heat transfer characteristics of the composition, specifically and preferably heat capacity, and all such amounts are within the scope of the present invention. In certain preferred embodiments, the third component of the present invention is present in an amount of from about 1 to about 99 percent by weight of the composition. As previously discussed, the third component, when present, is preferably a fluorinated ethane, preferably monofluoroethane (HFC-161), difluoroethane (HFC-152a), trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), and pantafluoroethane (HFC-125).

[0042] Applicants have therefore recognized that certain compositions of the present invention can be used to great advantage in numerous applications. For example, the present invention includes methods and compositions for heat transfer applications, foaming and blowing agent applications, propellant applications, sprayable composition applications, sterilization applications, aerosol applications, compatibilizer applications, fragrance and flavor applications, solvent applications, cleaning applications, leavening applications, etc. It is believed that one of ordinary skill in the art can readily adapt the present compositions for use in any and all such embodiments without undue experimentation.

[0043] heat transfer composition The compositions of the present invention are generally suitable for use in heat transfer applications, i.e., as heating and / or cooling media, including evaporative refrigerants.

[0044] For evaporative cooling applications, the compositions of the present invention are preferably contacted directly or indirectly with an object to be cooled, followed by evaporation or boiling during such contact, with the result that the boiling gas in accordance with the present composition absorbs heat from the object to be cooled. In such applications, the compositions of the present invention are preferably utilized, preferably in liquid form, by spraying or otherwise applying the liquid to the object to be cooled. In other evaporative cooling applications, a liquid composition in accordance with the present invention is preferably vented from a relatively high-pressure vessel to a relatively lower-pressure environment, where the object to be cooled is preferably brought into direct or indirect contact with the vessel containing the liquid composition of the present invention, without recovering or recompressing the vented gas. One particular application for this type of embodiment is the self-cooling of beverages, foodstuffs, small items, and the like. Prior to the invention described herein, conventional compositions such as HFC-152a and HFC-134a were used for such applications. However, such compositions have recently been viewed negatively in such applications due to the negative environmental impacts resulting from the release of these materials into the atmosphere. For example, the U.S. EPA has determined that the use of such conventional chemicals in this application is unacceptable due to the high global warming potential of these compounds and the harmful environmental effects that can result from their use. The compositions of the present invention, as described herein, have distinct advantages in this regard due to their low global warming potential and low ozone depletion potential. Additionally, the compositions are expected to find substantial utility in cooling electrical or electronic components during manufacturing or accelerated life testing. In accelerated life testing, components are heated and cooled in rapid succession to simulate their use. Thus, such uses are particularly advantageous in the semiconductor and computer board manufacturing industries. Another advantage of the compositions in this regard is that they are expected to exhibit contagious electrical properties when used in such applications. Another evaporative cooling application involves a method for temporarily interrupting the flow of a fluid through a conduit.Preferably, such a method comprises contacting a conduit, such as a water pipe, through which water flows, with a liquid composition according to the present invention, and allowing the liquid composition of the present invention to evaporate while in contact with the conduit so as to freeze the liquid contained therein, thereby temporarily stopping the flow of fluid through the conduit. Such a method comprises applying the composition to such conduit at a location downstream from the location where the composition is applied. or has a distinct advantage in terms of being able to carry out inspections or other work on the system connected to the conduit.

[0045] While it is contemplated that the compositions of the present invention may contain a wide range of amounts of the compounds of the present invention, it is generally preferred that the refrigerant compositions of the present invention contain a compound(s) according to Formula I, and even more preferably HFO-1234 (including HFO-1234ze and HFO-1234yf), in an amount of at least about 50% by weight of the composition, and even more preferably at least about 70% by weight. In certain embodiments, it is preferred that the heat transfer compositions of the present invention contain transHFO-1234ze. In certain preferred embodiments, it is preferred that the heat transfer compositions of the present invention contain at least about 80% by weight, and even more preferably at least about 90% by weight of HFO-1234, and even more preferably HFO-1234yf and / or HFO-1234ze. The heat transfer compositions of the present invention, in certain embodiments, comprise a combination of cisHFO-1234ze and transHFO-1234ze in a cis:trans weight ratio of preferably from about 1:99 to about 10:99, more preferably from about 1:99 to about 5:99, and even more preferably from about 1:99 to about 3:97.

[0046] The relative amounts of hydrofluoroolefins used in accordance with the present invention are preferably selected to produce a heat transfer fluid that has the required heat transfer capacity, particularly refrigeration capacity, and that is preferably non-flammable at the same time. As used herein, the term non-flammable refers to a fluid that is non-flammable in all proportions in air as measured by ASTM E-681.

[0047] The compositions of the present invention may contain other ingredients to enhance or provide certain functions to the composition, or in some cases to reduce the cost of the composition. For example, refrigerant compositions according to the present invention, particularly those used in vapor compression systems, generally contain a lubricant in an amount of about 30 to about 50% by weight of the composition. Additionally, the compositions may contain a co-refrigerant, or a compatibilizer, such as propane, to aid lubricant compatibility and / or solubility. Such compatibilizers, including propane, butane, and pentane, are preferably present in an amount of about 0.5 to about 5% by weight of the composition. Additionally, a combination of surfactants and solubilizers may be added to the compositions to aid oil solubility, as disclosed in U.S. Pat. No. 6,516,837, incorporated herein by reference. Commonly used refrigeration lubricants, such as polyol ethers (POE) and polyalkenyl glycols (PAG), PAG oils, silicone oils, mineral oils, alkylbenzenes (AB), and poly(alpha-olefins) (PAO), are used with hydrofluorocarbon (HFC) refrigerants in refrigerators and can be used with the refrigerant compositions of the present invention. Commercially available mineral oils include Witco LP 250® from Witco, Zerol 300® from Shrieve Chemical, Sunisco 3GS from Witco, and Calumet 100® from Calumet. Examples of suitable lubricants include Calumet R015 from Epson, Inc. Commercially available alkylbenzene lubricants include Zerol 150®. Commercially available esters include neopentyl glycol dipelargonate, available as Emery 2917®, and Hatcol 2370®. Other useful esters include phosphate esters, dibasic acid esters, and fluoroesters. In some cases, hydrocarbon-based oils have sufficient solubility for refrigerants composed of iodocarbons, and the combination of iodocarbons and hydrocarbon oils is more stable than other types of lubricants. Therefore, such combinations can be advantageous. Preferred lubricants include polyalkylene glycols and esters. Polyalkylene glycols are highly preferred in certain embodiments due to their current use in certain applications, such as mobile air conditioning. Of course, different mixtures of different types of lubricants may be used.

[0048] In certain preferred embodiments, the heat transfer composition comprises from about 10% to about 95% by weight of a compound of Formula I, more preferably one or more HFO-1234 compounds, and from about 5% to about 95% by weight of a compound of Formula I, more preferably one or more HFO-1234 compounds. It contains about 90% by weight of R-32.

[0049] The present methods, systems, and compositions are generally adaptable for use in a wide variety of heat transfer systems, particularly refrigeration systems such as air conditioning (including both stationary and mobile air conditioning systems), refrigeration, and heat pump systems. In certain preferred embodiments, the compositions of the present invention are used in stationary refrigeration systems, such as stationary air conditioning units and stationary chillers originally designed to use one or more of R-22, R-134a, R-404A, R-407C, R-410A, and R-507. Preferred compositions of the present invention tend to exhibit many desirable characteristics of these current refrigerants, including a GWP as low as or lower than current refrigerants, a capacity as high as or higher than such refrigerants, and a capacity substantially equivalent to or substantially comparable to, and preferably as high as or higher than, such refrigerants. In particular, Applicant has recognized that certain preferred embodiments of the present compositions tend to exhibit a relatively low global warming potential (GWP), preferably less than about 1000, more preferably less than about 500, and even more preferably less than about 150.

[0050] Many current refrigerant systems are currently adapted for use with current refrigerants, and it is believed that the compositions of the present invention are adaptable for use in many such systems, with or without modification of the system.

[0051] Generally, preferred heat transfer compositions of the present invention are non-azeotropic over much, and potentially all, of the temperature and pressure ranges of use. That is, mixtures of such components produce liquids at non-low boiling temperatures, thus resulting in what is known as "temperature glide" in evaporators and condensers. "Temperature glide" is the change in temperature that occurs when a non-azeotropic material condenses or evaporates. This glide is preferably considered with respect to the method and composition aspects of the present invention to provide a composition that most effectively matches the refrigerant composition it replaces. For a single component or azeotropic mixture, the temperature glide is zero. R-407C is a non-azeotropic mixture, having a glide of 5°C in typical applications; in certain preferred embodiments, the present compositions provide a temperature glide of about 5°C or less under actual or intended conditions of use.

[0052] The present compositions are also believed to be suitable as replacements for many compositions currently used in other applications, such as aerosols, foaming agents, etc., as described elsewhere herein.

[0053] Particularly preferred embodiments of the composition of the present invention are described below. HFC-32 / HFO-1234yf-based compositions In one preferred embodiment of the present invention, the composition comprises a first component comprising a major proportion of, and preferably consisting essentially of, HFC-32, and even more preferably consisting of, HFC-32; and a second component comprising, and preferably consisting essentially of, and even more preferably consisting of, HFO-1234yf. In such an embodiment, it is generally preferred that the amount of HFC-32 present in the composition be from about 10% to about 90% by weight of the composition, more preferably from about 20% to about 90% by weight of the composition, and even more preferably from about 25% to about 85% by weight of the composition, based on the total weight of HFC-32 and HFO-1234yf. However, Applicant notes that in certain embodiments, it is further preferred that the amount of HFC-32 be less than 10% by weight. For example, for embodiments in which the composition is intended for or will be used as a substitute for HFC-134a, HFC-32 is included in the composition in relatively small amounts, such as less than about 5%, and even more preferably less than about 3%. Indeed, in certain such HFC-134a substitute embodiments, it is desirable for the amount of HFC-32 in the composition to be less than about 1%, based on the total weight of HFC-32 and HFO-1234yf.

[0054] As previously described, the compositions in such preferred embodiments also include a second component comprising HFO-1234yf. In certain such embodiments, the second component comprises a major proportion of HFO-1234yf, preferably consisting essentially of HFO-1234yf, and even more preferably consisting of HFO-1234yf. The amount of HFO-1234yf present in the composition is preferably from about 10 to about 90% by weight of the composition, more preferably from about 10 to about 80% by weight of the composition, and even more preferably from about 15 to about 75% by weight of the composition.

[0055] According to certain preferred embodiments of the present invention, particularly and preferably for embodiments in which the composition is intended or used as a substitute or replacement for R-404A, the amount of HFO-1234yf present in the composition is about 40 to about 80 wt.%, more preferably about 50 to about 80 wt.%, and even more preferably about 60 to about 80 wt.%, based on the total weight of HFO-1234yf and HFC-32 in the composition. Applicants have discovered that compositions within this range provide refrigerant fluids that have a much lower global warming potential (GWP) than many standard refrigerants, including R-410A and R-404A, while at the same time exhibiting performance parameters commercially comparable to previously used refrigerants, including R-410A and R-404A in particular. One indicator of such performance is provided by AHRI "A" conditions around 95°F. In accordance with such guidelines, Applicants have surprisingly and / or advantageously discovered that compositions of the present invention comprising about 30 to about 50 wt.% HFO-1234yf, based on the total weight of HFO-1234yf and HFC-32 in the composition, can provide an excellent match in the discharge temperature parameter of a refrigerant such as R-22, while still achieving acceptable performance parameters with respect to capacity and efficiency. For such embodiments, compositions comprising about 35 to about 45 wt.% HFO-1234yf, and even more preferably about 40 wt.% HFO-1234yf, based on the total weight of HFO-1234yf and HFC-32 in the composition, are particularly preferred.

[0056] According to certain preferred embodiments of the present invention, the amount of HFO-1234yf present in the composition is from about 10 to about 50 wt.%, more preferably from about 20 to about 40 wt.%, and even more preferably from about 10 to about 30 wt.%, based on the total weight of HFO-1234yf and HFC-32 in the composition. Applicants have discovered that compositions within these ranges provide refrigerant fluids that have a much lower global warming potential (GWP) than many standard refrigerants, including R-404a and R-410A, while at the same time exhibiting performance parameters commercially comparable to previously used refrigerants, including R-410A, R-404a, and R-22, among others. One indicator of such performance is provided by AHRI "A" conditions at around 95°F.

[0057] Applicants have surprisingly and / or advantageously discovered that compositions of the present invention comprising about 60 to about 80 wt.% HFO-1234yf, based on the total weight of HFO-1234yf and HFC-32 in the composition, can provide an excellent match in capacity and efficiency parameters to refrigerants such as R-404a, while still achieving acceptable performance parameters with respect to discharge temperature. For such embodiments, compositions comprising about 65 to about 85 wt.% HFO-1234yf, and even more preferably about 70 wt.% HFO-1234yf, based on the total weight of HFO-1234yf and HFC-32 in the composition, are particularly preferred, especially for use as a substitute for R-404a.

[0058] Applicants have surprisingly and / or advantageously discovered that compositions of the present invention comprising from about 10 to about 50 wt. % HFO-1234yf, based on the total weight of HFO-1234yf and HFC-32 in the composition, can provide an excellent match in capacity and efficiency parameters to refrigerants such as R-410A, while still achieving acceptable performance parameters with respect to emissions. For such embodiments, the HFO-1234yf and HFC-32 in the composition can be used in combination with other refrigerants such as R-410A. Particularly preferred are compositions containing about 20 to about 40 wt. % HFO-1234yf, and even more preferably about 30 wt. % HFO-1234yf, based on the total weight of FC-32.

[0059] HFC-32 / HFO-1234ze-based compositions In one preferred embodiment of the invention, the composition comprises a first component, which comprises a major proportion of, and preferably consists essentially of, HFC-32, and even more preferably consists of, HFC-32, and a second component comprising, and preferably consisting essentially of, and even more preferably consisting of, HFO-1234ze. In such an embodiment, it is generally preferred that the amount of HFC-32 present in the composition be from about 3% to about 98% by weight of the composition, more preferably from about 10% to about 95% by weight of the composition, and even more preferably, from about 40% to about 95% by weight of the composition in certain embodiments, particularly those intended or used as replacements for 404a or 410A.

[0060] As previously described, in such preferred embodiments, the composition also includes a second component comprising HFO-1234ze. In certain such embodiments, the second component comprises a major proportion of HFO-1234ze, preferably transHFO-1234ze, and preferably consists essentially of HFO-1234ze, preferably transHFO-1234ze, and even more preferably consists of HFO-1234ze, preferably transHFO-1234ze. The amount of HFO-1234ze, preferably transHFO-1234ze, present in the composition is preferably from about 2 to about 97% by weight of the composition, more preferably from about 5 to about 90% by weight of the composition, and even more preferably, in certain embodiments, from about 5 to about 60% by weight of the composition.

[0061] According to certain preferred embodiments of the present invention, the amount of HFO-1234ze, preferably transHFO-1234ze, present in the composition is from about 25 to about 85 weight percent, based on the total weight of HFO-1234ze and HFC-32 in the composition. Applicants have discovered that compositions within this range provide refrigerant fluids that have a much lower global warming potential (GWP) than many standard refrigerants, including R-410A, while at the same time exhibiting performance parameters commercially comparable to previously used refrigerants, including R-404A, R-410A, and R-22, among others. One indicator of such performance is provided by AHRI "A" conditions at around 95°F.

[0062] In accordance with such guidelines, Applicants have surprisingly and / or advantageously discovered that compositions of the present invention comprising about 50 to about 70 wt.% HFO-1234ze, based on the total weight of HFO-1234ze and HFC-32 in the composition, can provide excellent matching in discharge temperature parameters of refrigerants such as R-22, while still achieving acceptable performance parameters with respect to capacity and efficiency. For such embodiments, compositions comprising about 35 to about 45 wt.% HFO-1234ze, and even more preferably about 55 wt.% HFO-1234ze, based on the total weight of HFO-1234ze and HFC-32 in the composition, are particularly preferred.

[0063] According to certain preferred embodiments of the present invention, the amount of HFO-1234ze present in the composition is from about 5 to about 30 wt.%, more preferably from about 5 to about 20 wt.%, and even more preferably about 10 wt.% in certain embodiments, based on the total weight of HFO-1234ze and HFC-32 in the composition. Applicants have discovered that compositions within these ranges and amounts provide refrigerant fluids that have a much lower Global Warming Potential (GWP) than many standard refrigerants, including R-410A, while at the same time exhibiting performance parameters that are commercially comparable to previously used refrigerants, including R-410A and R-22, among others.

[0064] According to another preferred embodiment, the applicant has surprisingly and / or advantageously found that: It has been discovered that compositions of the present invention containing from about 5 to about 30 wt.% HFO-1234ze, based on the total weight of HFO-1234ze and HFC-32 in the composition, can provide an excellent match in capacity and efficiency parameters to refrigerants such as R-410A, while still achieving acceptable performance parameters with respect to discharge temperature. For such embodiments, compositions containing from about 5 to about 25 wt.% HFO-1234ze, and even more preferably about 10 wt.% HFO-1234ze, based on the total weight of HFO-1234ze and HFC-32 in the composition, are particularly preferred.

[0065] Specifically, and preferably, according to certain preferred embodiments of the present invention, including those in which the composition is intended or used as a substitute or replacement for R-404A, the amount of HFO-1234ze present in the composition is about 40 to about 70 wt.%, more preferably about 40 to about 60 wt.%, more preferably about 45 to about 55 wt.%, and even more preferably about 50 wt.% in certain embodiments, based on the total weight of HFO-1234ze and HFC-32 in the composition. Applicants have discovered that compositions within these ranges and amounts provide refrigerant fluids that have a global warming potential (GWP) significantly lower than many standard refrigerants, including R-404A, while at the same time exhibiting performance parameters commercially comparable to previously used refrigerants, including R-404A in particular. One indicator of such performance is provided by AHRI "A" conditions at around 95°F. In accordance with such guidelines, Applicants have surprisingly and / or advantageously discovered that compositions of the present invention comprising from about 40 to about 70 wt.% HFO-1234ze, based on the total weight of HFO-1234ze and HFC-32 in the composition, can provide an excellent match in capacity and efficiency parameters to refrigerants such as R-404A, while still achieving acceptable performance parameters with respect to discharge temperature. For such embodiments, compositions comprising from about 40 to about 60 wt.% HFO-1234ze, and even more preferably about 50 wt.% HFO-1234ze, based on the total weight of HFO-1234ze and HFC-32 in the composition, are particularly preferred.

[0066] Specifically, and preferably, according to certain preferred embodiments of the present invention, including those in which the composition is intended or used as a substitute or replacement for R-134a, the amount of HFO-1234ze present in the composition is from about 80 to about 97 wt.%, more preferably from about 80 to about 90 wt.%, and even more preferably about 85 wt.%, based on the total weight of HFO-1234ze and HFC-32 in the composition. Applicants have discovered that compositions within these ranges and amounts have a much lower global warming potential (GWP) than many standard refrigerants, including R-134a, while at the same time providing refrigerant fluids that exhibit performance parameters commercially comparable to previously used refrigerants, including, particularly, R-134a.

[0067] HFC-32 / CF 3 Compositions based on I In one preferred embodiment of the invention, the composition comprises a first component that comprises a major proportion of, and preferably consists essentially of, and even more preferably consists of, HFC-32. In such an embodiment, it is generally preferred that the amount of HFC-32 present in the composition be from about 1% to about 60% by weight of the composition.

[0068] In such preferred embodiments, the composition also includes a second component comprising CF3I. In certain such embodiments, the second component comprises a major proportion of CF3I, preferably consists essentially of CF3I, and even more preferably consists of CF3I. The amount of CF3I present in the composition is preferably from about 5% to about 98% by weight of the composition. For embodiments in which the second component includes both CF3I and HFO-1225, the relative amounts of CF3I and HFO-1225 can vary widely, but in such embodiments, it is preferred that the amount of CF3I is from about 5% to about 98% by weight of the composition and the amount of HFO-1225 is from about 1% to about 65% by weight of the composition. For embodiments in which the second component includes CF3I and HFO-1225, a third component is optional, but if present, should be from about 1% to about 98% by weight of the composition. Preferably, it is present in an amount of 4% by weight. For embodiments in which the second component consists essentially of CF3I, i.e., the composition does not contain substantial amounts of HFO-1225, a third component is required and is preferably present in an amount of at least about 1% by weight of the composition.

[0069] It is contemplated that numerous combinations of compounds may be used as the third component of the present invention in this particular embodiment, and in a wide variety of relative concentrations, and all amounts and combinations are believed to be suitable for use in accordance with the teachings contained herein. However, in certain preferred embodiments in which the third component comprises one or more of monofluoroethane (HFC-161), difluoroethane (HFC-152a), trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125), 1,1,1,3-tetrafluoropropene (HFO-1234ze, including all isomers), and 1,1,1,2-tetrafluoropropene (HFO-1234yf), it is preferred that such components, if present, are selected from within the ranges set forth in Table 1 below (the amounts set forth are preceded by the modifier "about" and are intended to be understood as being based on weight percent of the composition).

[0070] [Table 2]

[0071] HFC-32 / HFO-1225 based compositions In these embodiments of the invention, the composition comprises a first component that comprises a major proportion of, and preferably consists essentially of, and even more preferably consists of, HFC-32. In such embodiments, it is generally preferred that the amount of HFC-32 present in the composition be from about 1% to about 60% by weight of the composition.

[0072] In such preferred embodiments, the composition also includes a second component comprising HFO-1225, preferably HFO-1225ye-Z. In certain such embodiments, the second component comprises a major proportion of HFO-1225, preferably consisting essentially of HFO-1225ye-Z, and even more preferably consisting of HFO-1225ye-Z. The amount of HFO-1225ye-Z present in the composition is preferably from about 5% to about 98% by weight of the composition. In such embodiments, a third component is optional, but if present, is preferably present in an amount of from about 1% to about 94% by weight of the composition.

[0073] It is contemplated that a wide variety of combinations of compounds may be used as the third component of the present invention in this particular embodiment, and in a wide variety of relative concentrations, and all amounts and combinations are believed to be suitable for use in accordance with the teachings contained herein. However, it is contemplated that the third component may be selected from the group consisting of monofluoroethane (HFC-161), difluoroethane (HFC-152a), trifluoroethane (HFC-143a), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-135a), 1,1,1,2-tetrafluoroethane (HFC-136a), 1,1,1,2-tetrafluoroethane (HFC-137a), 1,1,1,2-tetrafluoroethane (HFC-138a), 1,1,1,2-tetrafluoroethane (HFC-139a), 1,1,1,2-tetrafluoroethane (HFC-139b), 1,1,1,2-tetrafluoroethane (HFC-139c), 1,1,1,2-tetrafluoroethane (HFC-139b), 1,1,1,2-tetrafluoroethane (HFC-139c), 1,1,1,2-tetrafluoroethane (HFC-139a), 1,1,1,2-tetrafluoroethane (HFC-139b), 1,1,1,2-tetrafluoroethane (HFC-139c ... In certain preferred embodiments, the compositions include one or more of 1,3-tetrafluoropropene (HFO-1234ze, including all isomers), and 1,1,1,2-tetrafluoropropene (HFO-1234yf), when present, such components are preferably selected from within the ranges set forth in Table 2 below (the amounts set forth are preceded by the modifier "about" and are intended to be understood as being based on weight percent of the composition).

[0074] [Table 3]

[0075] Selection method One aspect of the present invention includes a method for selecting a heat transfer composition for use with an existing heat transfer system. As used herein, the term "existing heat transfer system" includes not only actual heat transfer systems that have been constructed and are in place, but also systems that have not yet been constructed but are envisioned and / or are in the design stage. One preferred embodiment provides a method for selecting a heat transfer composition for use with an existing heat transfer system that is designed for use with a previously known composition. In such cases, the previously known composition generally has a desired or expected heat capacity but also exhibits one or more undesirable characteristics. For example, the following previously known refrigerants each have a desirable heat capacity for the system in which they are used, but exhibit an undesirably high GWP, as shown below:

[0076] [Table 4]

[0077] Preferred method steps include analyzing system parameters in a manner sufficient to allow approximation of capacity for a current or design heat transfer fluid, providing a tool that allows approximation of capacity for two or more compositions of the present invention at the conditions of the current or design system, and utilizing these to select compositions for use in the current or design system. An example of such a tool is the chart provided in the Examples below. A computer program constructed in accordance with the teachings contained herein is another example of such a tool. In preferred embodiments, the tool can approximate, determine, or incorporate the GWP and / or flammability of the compositions of the present invention, and the selecting step includes selecting compositions to have a GWP of less than about 1000, even more preferably less than about 150, and / or to be non-flammable or have flammability within predetermined parameter ranges.

[0078] Methods and Systems The compositions of the present invention are useful in numerous processes and systems, including as heat transfer fluids in processes and systems for transferring heat, such as refrigerants used in refrigeration, air conditioning, and heat pump systems. The compositions are advantageous for use in aerosol-generating systems and methods, preferably comprising or consisting of an aerosol propellant in such systems and methods. Methods for forming foams and methods for extinguishing and suppressing fires are also included in certain aspects of the present invention. The present invention also provides, in certain aspects, a method for removing residue from an article, using the compositions as a solvent composition in such methods and systems.

[0079] Heat transfer methods and systems Preferred heat transfer methods generally involve providing a composition of the present invention and transferring heat to or from the composition by either sensible heat transfer, phase change heat transfer, or a combination thereof. For example, in certain preferred embodiments, the methods provide a refrigeration system comprising a refrigerant of the present invention and a method for producing heating or cooling by condensing and / or evaporating a composition of the present invention. In certain preferred embodiments, methods for cooling, including directly or indirectly cooling other fluids or objects, involve condensing a refrigerant composition comprising a composition of the present invention and then evaporating the refrigerant composition in the vicinity of the item to be cooled. As used herein, the term "object" refers not only to inanimate objects but also to living tissue, including animal tissue in general and human tissue in particular. For example, certain aspects of the present invention involve applying the compositions to human tissue for one or more therapeutic purposes, such as analgesic procedures, preliminary anesthesia, or as part of a treatment involving reducing the temperature of the treated body. In certain embodiments, application to an object involves providing the composition in liquid form under pressure, preferably in a pressurized container having a one-way release valve and / or nozzle, and spraying or otherwise applying the composition to the object, thereby releasing the liquid from the pressurized container. As the liquid evaporates from the sprayed surface, the surface cools.

[0080] Certain preferred methods for heating a fluid or object include condensing a refrigerant composition comprising a composition of the present invention in the vicinity of the fluid or object to be heated, and then evaporating the refrigerant composition. In light of the disclosure herein, those skilled in the art will readily heat and cool articles in accordance with the present invention without undue experimentation.

[0081] Applicants have found that in the systems and methods of the present invention, many of the important refrigerant system performance parameters are relatively close to those of the current refrigerant families described above. Those skilled in the art will recognize the substantial benefits of low-GWP and / or low-ozone-depleting refrigerants, which can be used as refrigerant substitutes with relatively minimal system modifications. The present invention, in certain embodiments, contemplates providing a method for improving existing systems, involving replacing a heat transfer fluid (e.g., a refrigerant) with a composition of the present invention without substantial system modifications. In certain preferred embodiments, the replacement step is a drop-in replacement, meaning that no major items of equipment need to be replaced to accommodate the composition of the present invention as a heat transfer fluid, without substantial system redesign. In certain preferred embodiments, the method involves a drop-in replacement, in which the system capacity is at least about 70%, preferably at least about 85%, and even more preferably at least about 90%, of the system capacity prior to replacement, and preferably no more than about 130%, even more preferably no more than about 115%, and even more preferably no more than about 110%. In certain preferred embodiments, the method comprises a drop-in replacement, wherein the suction pressure and / or discharge pressure of the system, and even more preferably both, are at least about 70%, more preferably at least about 90%, and even more preferably at least about 95% of the suction pressure and / or discharge pressure of the system prior to replacement, and preferably not more than about 130%, even more preferably not more than about 115%, and even more preferably not more than about 110%. The flow rate is at least about 80%, preferably at least about 90%, and preferably not more than about 130%, even more preferably not more than about 115%, even more preferably not more than about 110% of the flow rate.

[0082] In certain embodiments, the present invention provides for evaporating the present refrigerant composition and absorbing heat from the fluid or object to be cooled in proximity to the fluid or object to produce a vapor comprising the present composition. Preferably, the method includes the further step of compressing the refrigerant vapor, typically with a compressor or similar device, to produce a relatively high-pressure vapor of the present composition. The vapor compression step generally adds heat to the vapor, increasing the temperature of the relatively high-pressure vapor. Preferably, in such embodiments, the method includes removing from this relatively high-temperature, high-pressure vapor at least a portion of the heat added by the evaporation and compression steps. The heat removal step preferably includes condensing the high-temperature, high-pressure vapor while the vapor is still at a relatively high pressure to produce a relatively high-pressure liquid comprising the present composition. This relatively high-pressure liquid preferably undergoes a nominally isentropic pressure drop to produce a relatively low-temperature, low-pressure liquid. In such embodiments, the reduced-temperature refrigerant liquid is then evaporated by heat transferred from the object or fluid to be cooled.

[0083] In another method aspect of the present invention, the compositions of the present invention may be used in a method for producing heat which involves condensing a refrigerant comprising the composition in the vicinity of a liquid or fluid to be heated. As previously described, such methods are often reverse cycles to the refrigeration cycles previously described. [Example]

[0084] The following examples are given for the purpose of illustrating the invention without limiting its scope. Example 1 - HFC-32 and CF 3 I mesophilic system The capacity of the heat transfer composition (and particularly the refrigerant) indicates its cooling or heating capacity and provides an indication of the compressor's ability to deliver heat for a given volumetric flow rate of the refrigerant. In other words, given a particular compressor, the higher the capacity of the refrigerant, the more cooling or heating output will be delivered.

[0085] A refrigeration / air conditioning cycle system is simulated or provided with a condenser temperature of about 40°C, an evaporator temperature of about 2°C, a superheat of about 10°C, a subcooling temperature of about 5°C, and a compressor efficiency of 0.7 (these are typically considered typical "medium temperature" conditions). Several compositions of the present invention are simulated and / or tested based on a first component consisting of HFC-32, a second component consisting of CF3I, and one of a series of third components as previously described. For each third component, the relative concentrations of all three components that substantially match the capacity of R-410A under the conditions previously described are determined. Curves are then drawn or simulated (visually, mathematically, or a combination of each) for various concentrations of each component whose capacity substantially matches that of R-410A. Asterixis is then placed on this curve to indicate compositions having a GWP of 1000 or less, and diamonds are then placed on the curve to indicate compositions having a GWP of greater than 1000. This procedure is repeated for all three compounds listed above, as well as for the second compound, HFO-1225ye-Z. One example of a "tool" for selecting a refrigerant for this system is thus created and is shown as a chart in Figure 1. The chart in Figure 1 is analyzed to identify compositions that fall on or nearly fall on the curve and have a GWP of less than about 1000. Before or after this identification, the compositions are preferably analyzed for flammability, and then selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0086] Example 2 - HFC-32 / CO 2 and CF 3 I mesophilic system Example 1 is repeated, except that the first component of the heat transfer composition consists of 3 wt. % CO2 and 97 wt. % HFC-32, and the refrigerant whose capacity is to be matched is R-410A. The chart of Figure 2 is prepared and analyzed to identify compositions that fall on or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0087] Example 3 - HFC-32 / CO 2 and CF 3 I mesophilic system Example 1 is repeated, except that the first component of the heat transfer composition consists of 1 wt. % CO2 and 99 wt. % HFC-32, and the refrigerant whose capacity is to be matched is R-410A. The chart of Figure 3 is prepared and analyzed to identify compositions that fall on or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0088] Example 4 - HFC-32 / CO 2 and CF 3 I low temperature system Example 1 is repeated, except that the first component of the heat transfer composition consists of 3 wt. % CO2 and 99 wt. % HFC-32, the refrigerant to which its capacity is to be matched is R-410A, and the conditions are a condenser temperature of about 45°C, an evaporator temperature of about -34°C, a superheat of about 10°C, a subcooling of about 5°C, and a compressor efficiency of 0.7 (these are usually considered typical "low temperature" conditions). The chart of Figure 4 is prepared and analyzed to identify compositions that fall or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0089] Example 5 - HFC-32 / CO 2 and CF 3 I low temperature system Example 1 is repeated, except that the first component of the heat transfer composition consists of 1 wt. % CO2 and 99 wt. % HFC-32, the refrigerant to which its capacity is to be matched is R-410A, and the conditions are a condenser temperature of about 45°C, an evaporator temperature of about -34°C, a superheat of about 10°C, a subcooling of about 5°C, and a compressor efficiency of 0.7 (these are usually considered typical "low temperature" conditions). The chart of Figure 5 is prepared and analyzed to identify compositions that fall or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0090] Example 6 - Medium Temperature System of HFC-32 and HFO-1225 A refrigeration / air conditioning cycle system is simulated or provided with a condenser temperature of about 40°C, an evaporator temperature of about 2°C, a superheat of about 10°C, a subcooling temperature of about 5°C, and a compressor efficiency of 0.7 (these are typically considered typical "medium temperature" conditions). Several compositions of the present invention are simulated and / or tested based on a first component consisting of HFC-32, a second component consisting of HFO-1225ye-Z, and one of a series of third components as previously described. For each third component, the relative concentrations of all three components that substantially match the capacity of R-410A under the conditions previously described are determined. Curves are then drawn or simulated (visually, mathematically, or a combination of each) for various concentrations of each component whose capacity substantially matches that of R-410A. Asterixis is then placed on this curve to indicate compositions having a GWP of 1000 or less, and diamonds are then placed on the curve to indicate compositions having a GWP of greater than 1000. This procedure is repeated for all three compounds listed above, as well as for the second compound, HFO-1225ye-Z. One example of a "tool" for selecting a refrigerant for this system is thus created, and is shown as a chart in Figure 6. The chart in Figure 6 is analyzed to determine which compounds fall or nearly fall on the curve and their GWP Compositions are identified that have a flammability index of less than about 1000. Before or after this identification, the compositions are preferably analyzed for flammability and then selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0091] Example 7 - Low temperature system of HFC-32 and HFO-1225 Example 6 is repeated, except that the conditions are a condenser temperature of about 45°C, an evaporator temperature of about -34°C, a superheat of about 10°C, a subcooling of about 5°C, and a compressor efficiency of 0.7 (these are usually considered typical "low temperature" conditions). The chart of Figure 7 is prepared and analyzed to identify compositions that fall on or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the compositions are preferably analyzed for flammability, and then selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0092] Example 8 - HFC-32 / CO 2 and HFO-1225 medium temperature system Example 6 is repeated, except that the first component of the heat transfer composition consists of 3 wt. % CO2 and 97 wt. % HFC-32. The chart of Figure 8 is prepared and analyzed to identify compositions that fall on or approximately fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0093] Example 9 - HFC-32 / CO 2 and HFO-1225 medium temperature system Example 6 is repeated, except that the first component of the heat transfer composition consists of 1 wt. % CO2 and 97 wt. % HFC-32, and the refrigerant whose capacity is to be matched is R-410A. The chart of Figure 9 is prepared and analyzed to identify compositions that fall on or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0094] Example 10 - HFC-32 / CO 2 and HFO-1225 low temperature system Example 6 is repeated, except that the first component of the heat transfer composition consists of 3 wt. % CO2 and 97 wt. % HFC-32, and the conditions are a condenser temperature of about 45°C, an evaporator temperature of about -34°C, a superheat of about 10°C, a subcooling of about 5°C, and a compressor efficiency of 0.7 (these are usually considered typical "low temperature" conditions). The chart of Figure 10 is prepared and analyzed to identify compositions that fall or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0095] Example 11 - HFC-32 / CO 2 and HFO-1225 low temperature system Example 6 is repeated, except that the first component of the heat transfer composition consists of 1 wt. % CO2 and 99 wt. % HFC-32, and the conditions are a condenser temperature of about 45°C, an evaporator temperature of about -34°C, a superheat of about 10°C, a subcooling of about 5°C, and a compressor efficiency of 0.7 (these are usually considered typical "low temperature" conditions). The chart of Figure 11 is prepared and analyzed to identify compositions that fall or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the flammability of the compositions is preferably analyzed, and then the compositions are selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0096] Example 12 - HFC-32 and CF 3 I low temperature system Example 1 is repeated, except that the conditions are a condenser temperature of about 45°C, an evaporator temperature of about -34°C, a superheat of about 10°C, a subcooling of about 5°C, and a compressor efficiency of 0.7 (these are usually considered typical "low temperature" conditions). The chart of Figure 12 is prepared and analyzed to identify compositions that fall on or nearly fall on the curve and whose GWP is less than about 1000. Before or after this identification, the compositions are preferably analyzed for flammability, and then selected for use as original components of such systems or as replacements or improvements to such existing systems.

[0097] Example 13 Vapor-liquid equilibrium (VLE) measurements were performed on mixtures of HFO-1234ze(E) and R-32 using two separate methods. The first method was an open ebulliometer, which measured the bubble point temperature of the mixture at atmospheric pressure, and the results are shown in Table 3. The second method was a closed system, which allowed for pressures above atmospheric pressure, and the results are shown in Table 4.

[0098] [Table 5]

[0099] [Table 6]

[0100] Example 14 The VLE of HFO-1234yf and R-32 was measured by two separate methods: the first was an open ebulliometer, which measured the bubble point temperature of the mixture at atmospheric pressure, and the results are shown in Table 5. The second was a sealed system, which allowed for pressures above atmospheric, and the results are shown in Table 6.

[0101] [Table 7]

[0102] [Table 8]

[0103] Example 15 Using the data in Tables 3 and 4, the performance of these refrigerants in a typical air conditioning application was evaluated. The conditions of the air conditioning cycle were: Evaporator temperature = 2°C Condenser temperature = 40℃ Supercooling=5℃ Overheating=10℃ Isentropic compressor efficiency = 0.7 It was.

[0104] Under these conditions, the capacity, COP, compressor discharge temperature, and condenser and evaporator glide were calculated and are shown in Tables 7A and 7B. The cycle performance and GWP for these mixtures were also calculated and are shown in Tables 8A and 8B. One disadvantage of using pure R-32 is the high discharge temperature. The glide for HFO-1234ze(E) + R-32 mixtures is <9°C across all compositions, and the glide for HFO-1234yf + R-32 mixtures is <7°C across all compositions.

[0105] [Table 9]

[0106] [Table 10]

[0107] [Table 11]

[0108] [Table 12]

[0109] Example 16 The performance of these refrigerants in low temperature applications was evaluated using the data in Tables 3 and 4. The low temperature cycle conditions were: Evaporator temperature = -34℃ Condenser temperature = 45℃ Supercooling=10℃ Overheating=10℃ Isentropic compressor efficiency = 0.7 It was.

[0110] Under these conditions, the capacity, COP, compressor discharge temperature, and condenser and evaporator glide were calculated and are shown in Tables 9A and 9B. The cycle performance and GWP for these mixtures were also calculated and are shown in Tables 10A and 10B. One disadvantage of using pure R-32 is the high discharge temperature. The glide for HFO-1234ze(E) + R-32 mixtures is <9°C across all compositions, and the glide for HFO-1234yf + R-32 mixtures is <7°C across all compositions.

[0111] [Table 13]

[0112] [Table 14]

[0113] [Table 15]

[0114] [Table 16]

[0115] Those skilled in the art will recognize that the foregoing description and examples are illustrative of the present invention, but are not necessarily intended to limit the full and true broad scope of the invention as set forth in the claims.

Claims

1. Use of a heat transfer composition containing a refrigerant mixture consisting of 20% by weight of difluoromethane (HFC-32) and 80% by weight of 2,3,3,3-tetrafluoropropene (HFO-1234yf) as a substitute for R-404A in a low-temperature refrigeration system.

2. The use according to claim 1, wherein the heat transfer composition is provided in combination with a lubricant.

3. The use according to claim 2, wherein the lubricant is selected from polyol ester (POE), polyalkylene glycol (PAG), PAG oil, silicone oil, mineral oil, alkylbenzene (AB), and poly(alpha-olefin) (PAO).

4. Use of a heat transfer composition containing a refrigerant mixture consisting of 20% by weight of difluoromethane (HFC-32) and 80% by weight of 2,3,3,3-tetrafluoropropene (HFO-1234yf) as a substitute for R-404A in a medium-temperature refrigeration system.

5. The use according to claim 4, wherein the heat transfer composition is provided in combination with a lubricant.

6. The use according to claim 5, wherein the lubricant is selected from polyol ester (POE), polyalkylene glycol (PAG), PAG oil, silicone oil, mineral oil, alkylbenzene (AB), and poly(alpha-olefin) (PAO).

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