Azeotropic and azeotrope-like compositions of 1-chloro-1, 2 difluoroethylene and 2,3,3,3, - tetrafluoroprop-1-ene

Abstract

It is an object of the present invention to provide novel compositions that can provide unique properties to meet the requirements of low or zero ozone depletion potential and low global warming potential as compared to current HFCs and can function as refrigerants, heat transfer fluids, blowing agents, solvents, and the like.SOLUTION: Provided are azeotrope or azeotrope-like compositions consisting of 1-chloro-1, 2 difluoroethylene (R - 1122a) and 2333 - tetrafluoropropene (HFO - 1234yf), and uses thereof.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to azeotropic and azeotrope-like compositions comprising 1-chloro-1,2 difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf), and their uses. [Background technology]

[0002] Fluorocarbon-based fluids are widely used in industry in many applications, including as refrigerants, aerosol propellants, blowing agents, heat transfer media, and gaseous dielectrics. Due to environmental concerns associated with the use of some of these fluids, including their relatively high global warming potential, it is desirable to use fluids with low or even zero ozone depletion potential. Furthermore, the use of single-component fluids or azeotropic mixtures that do not fractionate on boiling and evaporation is desirable. Safety issues, such as flammability, can also limit the widespread adoption of refrigerants in commercial and residential applications. The selection of refrigerants for vapor-compression HVAC&R systems requires tradeoffs between performance, safety, and environmental impact. However, the identification of new, safe, and environmentally safe non-fractionating mixtures is complicated because azeotrope formation is not easily predictable.

[0003] The industry is constantly seeking new fluorocarbon-based mixtures that offer alternatives and are considered environmentally safe replacements for CFCs and HCFCs.

[0004] The Montreal Protocol for the Protection of the Ozone Layer mandates the phasing out of the use of chlorofluorocarbons (CFCs). Ozone-friendly materials, such as hydrofluorocarbons (HFCs) like HFC-134a, have replaced the chlorofluorocarbons. The latter compounds have been proven to be greenhouse gases that cause global warming and were regulated by the Kyoto Protocol on Climate Change. The new replacement materials, hydrofluoropropenes, have been shown to be environmentally acceptable, i.e., they have zero ozone depletion potential (ODP) and an acceptably low GWP. Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide novel compositions that can provide unique properties that meet the demands of low or no ozone depletion potential and low global warming potential compared to current HFCs, and that can function as refrigerants, heat transfer fluids, blowing agents, solvents, etc. [Means for solving the problem]

[0006] The present inventors have developed several compositions that help meet the continuing need for replacements for CFCs, HCFCs, and HFCs. According to certain embodiments, the present invention provides azeotropic or azeotrope-like compositions comprising 1-chloro-1,2 difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf).

[0007] Preferred compositions of the present invention tend to be low to non-flammable and exhibit relatively low global warming potentials ("GWP") Accordingly, Applicants have recognized that such compositions can be used to great advantage in many applications, including as replacements for CFCs, HCFCs, and HFCs (e.g., HCFC-23, HFC-134a, HFC-245fa, HFC-365mfc) in refrigerants, aerosols, and other applications.

[0008] Additionally, Applicants have surprisingly recognized that azeotropic or azeotrope-like compositions of 1-chloro-1,2 difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf) can be formed. Accordingly, in another embodiment, the present invention provides a method for producing an azeotrope-like composition, comprising combining 1-chloro-1,2 difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf) in amounts effective to produce an azeotrope-like composition.

[0009] Additionally, Applicants have recognized that the azeotrope-like compositions of the present invention exhibit properties that make them advantageous for use as refrigerant compositions, or in refrigerant compositions and blowing agents. Accordingly, in yet another embodiment, the present invention provides refrigerant compositions and / or blowing agents, and solvents, comprising an azeotrope-like composition of 1-chloro-1,2 difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf). [Brief explanation of the drawings]

[0010] [Figure 1] Figure 1 shows the vapor-liquid equilibrium plot for HFO-1122a and R-1234yf using COSMO-RS2015 modeling. [Figure 2] Figure 2 shows the vapor-liquid equilibrium plot for HFO-1122a and R-1234yf using COSMO-RS2017 modeling. DETAILED DESCRIPTION OF THE INVENTION

[0011] Azeotrope-like compositions As used herein, the term "azeotrope-like" is intended broadly to include both compositions that are strictly azeotropes and compositions that behave like azeotropes. From basic principles, the thermodynamic state of a fluid is defined by pressure, temperature, liquid composition, and vapor composition. An azeotrope is a system of two or more components whose liquid and vapor compositions are equal at a given pressure and temperature. In practice, this means that the components of an azeotrope are at a constant boiling point and cannot separate during a phase change.

[0012] The azeotrope-like compositions of the present invention may contain additional components that do not form a new azeotrope-like system or that are not present in the initial distillation fraction. The initial distillation fraction is the first fraction obtained after the distillation column has demonstrated steady-state operation under total reflux conditions. One method for determining whether the addition of a component will form a new azeotrope-like system and fall outside the scope of the present invention is to distill a sample of the composition containing that component under conditions expected to separate the non-azeotropic mixture into its individual components. If the mixture containing the added component is non-azeotrope-like, the added component will fractionate from the azeotrope-like components. If the mixture is azeotrope-like, a finite initial distillation fraction containing all of the mixture components will be constant-boiling or behave as a single substance.

[0013] Thus, another characteristic of azeotrope-like compositions is that there is a series of compositions containing the same components in varying proportions that are azeotrope-like or constant-boiling. All such compositions are intended to be covered by the terms "azeotrope-like" and "constant-boiling." As an example, it is well known that changing pressure will at least slightly change the composition of a given azeotrope, as will the boiling point of the composition. Thus, an azeotrope of A and B represents a unique type of relationship, but its composition changes with temperature and / or pressure. Thus, for azeotrope-like compositions, there is a series of compositions containing the same components in varying proportions that are azeotrope-like. All such compositions are intended to be covered by the term azeotrope-like as used herein.

[0014] It is well recognized in the art that the formation of an azeotrope is impossible to predict. Unexpectedly, applicants have discovered that the combination of 1-chloro-1,2-difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf) forms an azeotrope or azeotrope-like blend.

[0015] According to certain preferred embodiments, the azeotropic or azeotrope-like compositions of the present invention comprise, and preferably consist essentially of, effective azeotropic or azeotrope-like amounts of 1-chloro-1,2-difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf). As used herein, the term "effective azeotrope-like amount" refers to the amount of each component that, when combined with the other component, results in the formation of the azeotrope-like compositions of the present invention. Preferably, the azeotrope-like compositions comprise, and preferably consist essentially of, about 99 to about 1 mole % 1-chloro-1,2-difluoroethylene (R-1122a) and about 1 to about 99 mole % 2,3,3,3-tetrafluoropropene (HFO-1234yf). More preferably, the azeotrope-like composition comprises, preferably consists essentially of, about 10 to about 70 mol% 1-chloro-1,2-difluoroethylene (R-1122a) and about 30 to about 90 mol% 2,3,3,3-tetrafluoropropene (HFO-1234yf). Even more preferably, the azeotrope-like composition comprises, preferably consists essentially of, about 10 to about 40 mol% 1-chloro-1,2-difluoroethylene (R-1122a) and about 60 to about 99 mol% 2,3,3,3-tetrafluoropropene (HFO-1234yf). More preferably, the azeotrope-like composition comprises, preferably consists essentially of, 40 mol% 1-chloro-1,2-difluoroethylene (R-1122a) and about 60 mol% 2,3,3,3-tetrafluoropropene (HFO-1234yf). Unless otherwise specified, the mole percentages disclosed herein are based on the total moles of 1-chloro-1,2 difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf) in the composition.

[0016] The azeotrope-like compositions of the present invention can be produced by combining effective azeotropic or azeotrope-like amounts of 1-chloro-1,2-difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf). Any of a wide variety of methods known in the art for combining two or more components to form a composition can be adapted for use in the present method for producing azeotrope-like compositions. For example, 1-chloro-1,2-difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf) can be manually and / or mechanically mixed, blended, or contacted as part of a batch or continuous reaction and / or process, or via a combination of two or more such steps. In light of the disclosure herein, one of ordinary skill in the art can readily prepare azeotrope-like compositions according to the present invention without undue experimentation.

[0017] Additives of the composition The azeotrope or azeotrope-like compositions of the present invention may further comprise any of a variety of optional additives including stabilizers, metal passivators, corrosion inhibitors, and the like.

[0018] In certain preferred embodiments, the compositions of the present invention further comprise a lubricant. Any of a variety of conventional lubricants can be used in the compositions of the present invention. A key requirement for a lubricant is that, when used in a refrigerant system, there must be sufficient lubricant returning to the system's compressor so that the compressor is lubricated. Therefore, the suitability of a lubricant for a given system is determined in part by the refrigerant / lubricant characteristics and in part by the characteristics of the system in which it will be used. Examples of suitable lubricants include mineral oil, alkyl benzene, polyol ester (including polyalkylene glycols, PAG oils, etc.), and the like. Mineral oils containing paraffinic or naphthenic oils are commercially available. Commercially available mineral oils include Witco LP250® from Witco, Zerol 300® from Shrieve Chemical, Sunisco 3GS from Witco, and Calumet R015 from Calumet. Commercially available alkyl benzene 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. Preferred lubricants include polyalkylene glycols and esters. Certain more preferred lubricants include polyalkylene glycols.

[0019] Uses of the composition The present compositions have utility in a wide range of applications. For example, one embodiment of the present invention relates to refrigerant compositions comprising the present azeotrope-like compositions.

[0020] The refrigerant compositions of the present invention can be used in any of a wide variety of refrigeration systems, including air conditioning, refrigeration, heat pumps, chillers, HVAC systems, and the like. In certain preferred embodiments, the compositions of the present invention are used in refrigeration systems originally designed for use with HCFC or HFC refrigerants, such as HCFC-12 or HFC-134a, for example. Preferred compositions of the present invention tend to exhibit many of the desirable properties of HFC-134a and other HFC refrigerants, including comparable or lower GWPs than conventional HFC refrigerants and comparable or similar capacities to such refrigerants. Furthermore, the relatively constant boiling point nature of the compositions of the present invention makes them more desirable than certain conventional HFCs for use as refrigerants in many applications.

[0021] In certain other preferred embodiments, the compositions are used in refrigeration systems originally designed for use with HFC refrigerants. The preferred refrigeration compositions of the present invention can be used in refrigeration systems containing lubricants traditionally used with CHC refrigerants (such as mineral oil, silicone oil, polyalkylene glycol oil, etc.), or can be used with other lubricants traditionally used with HFC refrigerants. As used herein, the term "refrigeration system" generally refers to any system or device that uses a refrigerant to provide cooling, or any part or portion of such a system or device. Such refrigeration systems include, for example, air conditioners, electric refrigerators, chillers, transport refrigeration systems, commercial refrigeration systems, etc.

[0022] Any of a wide variety of methods for introducing the refrigerant composition of the present invention into a refrigeration system can be used in the present invention. For example, one method involves attaching a refrigerant container to the low-pressure side of the refrigeration system and operating the refrigeration system compressor to draw the refrigerant into the system. In such an embodiment, the refrigerant container can be placed on a scale so that the amount of refrigerant composition entering the system can be monitored. Once the desired amount of refrigerant composition has been introduced into the system, charging is stopped. Alternatively, a wide variety of charging tools are commercially available and known to those skilled in the art. Thus, in light of the above disclosure, one skilled in the art can readily introduce the refrigerant composition of the present invention into a refrigeration system according to the present invention without undue experimentation.

[0023] According to certain other embodiments, the present invention provides refrigeration systems comprising the refrigerants of the present invention, and methods of heating or cooling by condensing and / or evaporating the compositions of the present invention. In certain preferred embodiments, a method of cooling an article according to the present invention comprises condensing a refrigerant composition comprising the azeotrope-like composition of the present invention, and then evaporating the refrigerant composition near the article to be cooled. A certain preferred method of heating an article comprises condensing a refrigerant composition comprising the azeotrope-like composition of the present invention, and then evaporating the refrigerant composition near the article to be heated. In light of the disclosure herein, one of ordinary skill in the art will be readily able to heat and cool articles according to the present invention without undue experimentation.

[0024] In another embodiment, the azeotrope-like compositions of the present invention can be used alone or in combination with known propellants as a propellant in a sprayable composition. The propellant composition comprises, more preferably consists essentially of, and even more preferably consists of, the azeotrope-like compositions of the present invention. Active ingredients to be sprayed together with inactive ingredients, solvents, and other materials may also be present in the sprayable mixture. Preferably, the sprayable composition is an aerosol. Suitable active substances to be sprayed include, but are not limited to, cosmetic materials such as deodorants, perfumes, hairsprays, cleansers, and abrasives, and pharmaceuticals such as asthma and breath fresheners.

[0025] Yet another embodiment of the present invention relates to a blowing agent comprising one or more azeotrope-like compositions of the present invention. In other embodiments, the present invention provides foamable compositions, preferably polyurethane and polyisocyanurate foam compositions, and methods for producing the foams. In such foam embodiments, one or more of the present azeotrope-like compositions are included as a blowing agent in a foamable composition, which preferably includes one or more additional components, as known in the art, that can react to expand under appropriate conditions to form a foam or cellular structure, as known in the art. Any of the methods known in the art can be used or adapted for use in accordance with the foam embodiments of the present invention.

[0026] Another embodiment of the present invention relates to a method for preparing a foamed thermoplastic product as follows: A foamable polymer composition is prepared by blending the components that make up the foamable polymer composition in any order. Typically, the foamable polymer composition is prepared by plasticizing a polymer resin and then blending the components of a blowing agent composition at an initial pressure. A common process for plasticizing a polymer resin is thermoplasticization, which involves heating the polymer resin sufficiently to soften it and blending it with a blowing agent composition. Generally, thermoplasticization involves heating a thermoplastic polymer resin to or near its glass transition temperature (Tg), or, for crystalline polymers, its melting temperature (Tm).

[0027] Other applications of the present azeotrope-like compositions include use as solvents, cleaners, etc. Examples include vapor degreasing, precision cleaning, electronics cleaning, dry cleaning, solvent etch cleaning, carrier solvents for depositing lubricants and mold release agents, and other solvent or surface treatments. One of ordinary skill in the art can readily adapt the present compositions for use in such applications without undue experimentation. [Example]

[0028] To determine the equilibrium liquid and vapor mole fractions at atmospheric pressure and whether azeotropic and / or azeotrope-like mixtures can be obtained using the refrigerant R-1234yf, a refrigerant mixture consisting primarily of cis-HFO-1122a and trans-HFO-1122a was modeled using COSMO-RS. COSMO-RS (Conductor-like Screening Model for Real Solvents) is a quantum chemical model used to predict the thermodynamic properties of molecules. The simulation results shown in Table 1 and Figures 1 and 2 were obtained using the 2015 and 2017 versions of COSMOtherm. Both parameterizations of the model show no discernible difference in boiling points between the cis (Z) and trans (E) isomers of R-1122a. The model indicates a potential azeotrope between HFO-1122a and R-1234yf at a molar ratio of approximately 10 / 90 or 40 / 60, depending on the model parameterization. The isomerism of HFO-1122a does not appear to affect the azeotropic ratio. The model indicates that potential azeotrope-like combinations between HFO-1122a and R-1234yf are in molar ratios of approximately 10 / 90 to 40 / 60.

[0029] [Table 1]

Claims

1. An azeotrope-like composition comprising effective amounts of 1-chloro-1,2 difluoroethylene (R-1122a) and 2,3,3,3-tetrafluoropropene (HFO-1234yf).

2. 2. The azeotrope-like composition of claim 1, wherein the molar ratio of 1-chloro-1,2-difluoroethylene (R-1122a) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) ranges from about 99 to 1 to about 99 to 1.

3. 2. The azeotrope-like composition of claim 1, wherein the molar ratio of 1-chloro-1,2-difluoroethylene (R-1122a) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) ranges from about 10 to about 70 to about 90 to 30.

4. 2. The azeotrope-like composition of claim 1, wherein the molar ratio of 1-chloro-1,2-difluoroethylene (R-1122a) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) ranges from about 10 to about 40 to about 90 to 60.

5. 2. The azeotrope-like composition of claim 1, wherein the molar ratio of 1-chloro-1,2-difluoroethylene (R-1122a) to 2,3,3,3-tetrafluoropropene (HFO-1234yf) is about 10 to 90.

Images