Compositions, systems, and methods for incorporating PAG lubricants or refrigerants into air conditioning systems using lower or low GWP refrigerants or refrigerant blends

Abstract

To provide a quick and convenient way to convey lubricants into an A / C system without the use of a manual injector.SOLUTION: Compositions, systems, and methods for introducing lubricants and additives designed to work with environmentally friendly refrigerants into vehicle heat management systems including passenger compartment air-conditioning (A / C) systems are disclosed. Methods for loading lubricants and specific additives using environmentally desirable (low GWP) refrigerant or refrigerant blend compositions into an environmentally friendly system, such as a system that uses HFO-1234yf, are also disclosed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to compositions, systems, and methods for delivering lubricants and additives designed to work with environmentally friendly refrigerants in vehicle thermal management systems, including cabin air conditioning (A / C) systems. More specifically, the present invention relates to methods for filling environmentally friendly systems, such as systems using HFO-1234yf, with lubricants and certain additives using environmentally desirable (low GWP) refrigerants or refrigerant blend compositions. The present invention further relates to methods for filling environmentally friendly systems, such as systems using HFO-1234yf, with refrigerants containing lubricants and certain additives. [Background technology]

[0002] Since the mid-1990s, automotive air conditioning (A / C) systems have used R-134a refrigerant in a vapor compression cycle. Currently, due to environmental and social pressures, automotive manufacturers worldwide are transitioning to HFO-1234yf (2,3,3,3-tetrafluoropropene), a low-global warming potential (GWP) refrigerant, as their vehicle A / C refrigerant. In a traditional vapor compression A / C system, an A / C compressor circulates the refrigerant through the A / C system to achieve cooling. Therefore, the A / C compressor is essential for the operation of the A / C system. As the heart of the A / C system, the A / C compressor pumps the hydraulic fluid through the system. Without a properly functioning A / C compressor, the A / C system will not function.

[0003] To function properly, A / C compressors require lubricating oil with the correct physical parameters (viscosity, humidity, TAN, etc.). The lubricating oil must circulate completely through the A / C system. The lubricating oil must be transported by the refrigerant from one part of the system to the next, and the lubricating oil, when inside the compressor, must be able to transport the refrigerant from one part of the system to another while also providing lubrication. Therefore, refrigerant / oil compatibility over the A / C system operating range of 0°C to 40°C is essential for the system to function effectively.

[0004] Automotive original equipment manufacturers (OEMs) typically add A / C lubricant during the initial vehicle A / C fill process. A / C systems may require repair due to component failure (broken hoses or piping) or a vehicle accident that compromises the A / C system. The automotive aftermarket or service industry typically employs recovery, recycling, and recharge (R / R / R) equipment to refill / recharge the A / C system with refrigerant and lubricant after repairs. However, current R / R / R equipment designed for use with HFO-1234yf, based on SAE J2843, specifically Section 8.9.5.1 of the aforementioned SAE standard (incorporated herein by reference), does not allow for automatic injection of lubricant into the system after repairs by the R / R / R equipment. The lubricant must be "hand-injected" or "machine-injected." Each of these options involves filling an injector with lubricant and then attaching a hose to the low side of the A / C system. When the vehicle is started, the A / C system is set to maximum cooling, which also activates the A / C compressor. When the A / C compressor begins to cycle, the attached injectors are turned to the open position, and lubricating oil is conveyed along the hoses to the A / C system.

[0005] While this method can be used, it is a time-consuming process and requires the use of a manual pumping mechanism to force the lubricant through a connected hose to the A / C service port. The lubricant is drawn into the system by the A / C compressor. During the delivery process, the lubricant may adhere to the walls of the hose, making it difficult to deliver a sufficient amount of lubricant to the system. Therefore, there is a need in the art for a method of quickly and conveniently delivering lubricant to an A / C system without the use of a manual injector.

[0006] It should also be noted that in some cases it may be advantageous to use a similar delivery process to deliver refrigerants, refrigerants containing lubricants, or refrigerants containing other performance enhancing additives into A / C systems using this same delivery method. Summary of the Invention [Means for solving the problem]

[0007] The present invention solves problems associated with conventional compositions, systems, and methods by providing a low-GWP refrigerant that can be used to inject lubricant into low-GWP HFO-1234yf automotive A / C systems using common A / C aftermarket refill hoses. In a manual injector or manual pump, lubricant flow is controlled by the viscosity of the lubricant and the suction of the A / C compressor. In the method of the present invention, a refrigerant is used to transport the lubricant and / or lubricant additive package through the A / C hose without adhering to the hose, thereby ensuring more lubricant or lubricant / additive package is introduced into the A / C system, thereby improving material flow.

[0008] The use of a manual injector or manual pump can result in lubricant deposits on the hose piping connecting to the A / C system. Because the refrigerant transports and delivers the lubricant into the A / C system, using a refrigerant to transfer the lubricant into the system ensures that more lubricant is introduced into the A / C system compared to manual or pump injectors. The lubricant or lubricant / additive and refrigerant are packaged together in a conventional container or can under conditions in which the lubricant and refrigerant are miscible. Upon being discharged from the container, the refrigerant components change state from a compressed liquefied gas to a gas, while the oil components are atomized. During this process, the refrigerant, which is miscible with the lubricant, atomizes the lubricant or lubricant / additive mixture and transports it further along the hose into the A / C system before it can precipitate on the walls of the A / C refill hose.

[0009] One aspect of the present invention relates to a composition comprising about 50 to about 80 weight percent of a PAG lubricant and about 20 to about 50 weight percent of a low GWP refrigerant.

[0010] Another aspect of the present invention relates to a composition comprising about 60 to about 65 weight percent of a PAG lubricant and about 35 to about 40 weight percent of a low GWP refrigerant.

[0011] Another embodiment of the present invention relates to the above composition, further comprising about 1 to 5% by weight of an acid scavenger.

[0012] Another aspect of the invention relates to any of the above compositions further comprising about 1-5% by weight of a performance enhancer.

[0013] A further aspect of the invention relates to any of the above compositions further comprising about 1 to 10 weight percent of a flame suppressant.

[0014] One aspect of the present invention relates to a container containing any of the above compositions for use in delivering the composition directly into a vehicle A / C system.

[0015] One aspect of the present invention relates to a method for delivering PAG lubricant into a vehicle A / C system using any of the compositions or containers described above.

[0016] Another aspect of the present invention includes the method described above, further comprising delivering an acid scavenger into the vehicle A / C system.

[0017] Another aspect of the present invention includes the method described above, further comprising delivering a performance enhancer into a vehicle A / C system.

[0018] Another aspect of the present invention includes the method described above, further comprising delivering a fire suppressant into a vehicle A / C system.

[0019] A further aspect of the present invention includes the above method, wherein the method is carried out under pressure and temperature conditions in which the lubricating oil is miscible with the refrigerant.

[0020] One aspect of the present invention includes a system for delivering any of the above compositions, methods, and containers to an automotive A / C system, including a container containing the composition, a compressor, a condenser, a dryer, an expansion valve, and an evaporator.

[0021] A further aspect of the invention involves the use of a kit as shown in Figure 2 to provide compositions for use in any of the compositions and methods described above.

[0022] Another aspect of the present invention relates to a composition comprising from about 1 to about 15 weight percent of a PAG lubricant and from about 85 to about 99 weight percent of a low GWP refrigerant.

[0023] A further aspect of the present invention relates to a composition comprising about 1 to about 10 weight percent of a PAG lubricant and about 90 to about 99 weight percent of a low GWP refrigerant.

[0024] A further aspect of the present invention relates to a composition comprising about 1 to about 5 weight percent of a PAG lubricant and about 95 to about 99 weight percent of a low GWP refrigerant.

[0025] The various aspects and embodiments disclosed herein can be used alone or in various combinations with each other. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram of a system for introducing the compositions of the present invention into an A / C system. [Figure 2] 1 is a photograph of a kit for use in delivering a composition of the present invention from a container into an A / C system. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention generally relates to compositions comprising lubricants and additives designed to work with environmentally friendly refrigerants. More specifically, the present invention relates to compositions for use in A / C systems comprising or consisting essentially of about 50 to about 80 wt %, about 55 to about 70 wt %, or about 60 to about 65 wt % PAG lubricant, about 0 to about 5 wt % additive, and about 20 to about 50 wt %, about 30 to about 45 wt %, or about 35 to about 40 wt % low GWP refrigerant or refrigerant blend.

[0028] The present invention further relates to a composition comprising, or consisting essentially of, from about 1 to about 15 wt %, from about 1 to about 10 wt %, or from about 1 to about 5 wt % of a PAG lubricant, from about 0 to about 5 wt % of an additive, and from about 85 to about 99 wt %, from about 90 to about 99 wt %, or from about 95 to about 99 wt % of a low GWP refrigerant or refrigerant blend.

[0029] Lubricating oil The lubricating oil selected for this composition preferably has sufficient solubility in the vehicle's A / C refrigerant to ensure that the lubricating oil can be returned from the evaporator to the compressor. Furthermore, the lubricating oil preferably has a relatively low viscosity at low temperatures so that the lubricating oil can pass through the cold evaporator. In a preferred embodiment, the lubricating oil and the A / C refrigerant are miscible over a wide temperature range. A preferred lubricating oil may be one or more polar oxygenates. Preferred polar oxygenates include polyalkylene oxides, also known as polyalkylene glycols (PAGs).

[0030] As used herein, polyalkylene glycols include compounds containing two or more alkylene oxides, one or more of which are terminated by a moiety (group) that does not contain an active hydrogen atom. Any alkylene oxide that promotes lubrication can be used with ethylene oxide, with propylene oxide being preferred, and propylene oxide being more preferred. End-capping moieties include any moiety that does not interfere with lubrication or cooling. Preferred end-capping moieties include lower alkyl groups, with C1-4 lower alkyl groups being more preferred. Preferred PAG lubricants include one or any combination of alkyl ether-capped compounds, ester-capped compounds, or mono-ols with at least one hydroxyl group. Preferred alkylene glycols are single- or double-end-capped, with double-capping being more preferred.

[0031] In a preferred embodiment, the lubricating oil is soluble in vehicle A / C system refrigerants at temperatures between about 0°C and about 100°C, more preferably within the range of about 0°C to about 40°C, and even more specifically between 5°C and 40°C. In another embodiment, high temperature solubility is not preferred because attempting to maintain the lubricating oil in the compressor is not a priority. In this embodiment, the lubricating oil is soluble at temperatures above about 70°C, more preferably above about 80°C, and most preferably at temperatures between 90°C and 95°C.

[0032] The lubricating oil may have a kinematic viscosity (measured at 40°C according to ASTM D445) of greater than about 5 cSt, preferably greater than about 10 cSt, and most preferably greater than about 20 cSt. The lubricating oil may have a kinematic viscosity (measured at 40°C according to ASTM D445) of less than about 600 cSt, more preferably less than about 320 cSt, and most preferably less than about 210 cSt. Ideally, the lubricating oil has a kinematic viscosity of 40-50 cSt when measured at 40°C according to ASTM D445.

[0033] The lubricating oil preferably has a molecular weight of about 1000 to about 4000, more preferably about 1500 to about 3500 (as measured by gel permeation chromatography (GPC) or time-of-flight mass spectrometry (TOF-MS)). Lubricating oils having molecular weights within these ranges provide more favorable Falex wear test results compared to lubricating oils having molecular weights outside these ranges. Table 1 shows suitable properties of lubricating oils for use with the compositions of the present invention.

[0034] [Table 1]

[0035] Additionally, the PAG lubricant used in the present compositions should have material compatibility with elastomers and plastics typically used in vehicle A / C systems, such as Neoprene WRT (polychloroprene / 2,3-dichloro-1,3-butadiene copolymer), HNBR (hydrogenated nitrile butadiene rubber), NBR (nitrile butadiene rubber), EPDM (ethylene propylene diene monomer), silicone, and butyl rubber, as measured by ASHRAE 97:2007, "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems," for two weeks at 100°C. Similarly, the PAG lubricants used should have good material compatibility with plastic materials, i.e., polyester, nylon, epoxy, polyethylene, terephthalate, and polyimide, as measured by ASHRAE 97:2007, "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems," at 100°C for two weeks. Plastics and elastomers used in conjunction with the above PAG lubricants and HFO-1234yf should have a weight gain of less than about 10%, less than about 8%, or less than about 7%, as measured by durometer, or a linear expansion of less than about 10%, less than about 8%, or less than about 7%, or a hardness change of less than about 10%, less than about 8%, or less than about 7%, as measured by durometer. Ideally, plastics and elastomers should have a weight gain of less than 10%, a linear expansion of less than 10%, or less than a hardness change in at least two properties, as measured by durometer, and preferably less than 10% in all three properties.

[0036] Several PAG lubricants have been found to have the requisite miscibility with a particular low GWP refrigerant, namely HFO-1234yf (available from The Chemours Company as Opteon™ refrigerant), over a desired temperature range, the desired lubricant viscosity, and the desired elastomer / plastic material compatibility. Specifically, the PAGs are known as 46 cSt type PAG oils and are known by the following trademarks: "ND-12," "SP-A2," "PS-D1," and "FD46XG."

[0037] refrigerant The refrigerant portion of the mixture includes at least one hydrofluoroolefin (or more commonly referred to as an HFO-based refrigerant), but is not limited to one specific HFO refrigerant. Hydrofluoroolefins have low global warming potential (GWP) and an ozone depletion potential (ODP) of zero. The Intergovernmental Panel on Climate Change (IPCC) regularly reviews and defines the GWP of fluorocarbons. The hydrofluoroolefin refrigerants embodied in the present invention have a GWP of less than about 100 GWP, but typically have a GWP of less than 10, or even as low as 1 GWP. A particularly useful hydrofluoroolefin includes HFO-1234yf. According to the UN's IPCC Fifth Assessment Report (AR5), HFO-1234yf has a GWP of less than 1.

[0038] Global warming potential (GWP) is an index used to estimate the relative global warming contribution resulting from the atmospheric emission of one kilogram of a particular greenhouse gas compared to the emission of one kilogram of carbon dioxide. GWP can be calculated for various time horizons and indicates the effect of a given gas over its atmospheric lifetime. The GWP for a 100-year time horizon is the commonly referenced value. For mixtures, a weighted average can be calculated based on the individual GWPs of each component.

[0039] Leck et al. (U.S. Patent Application Publication No. 2007 / 0187639, paragraph 10, which is incorporated herein by reference) further lists examples of unsaturated fluorocarbon refrigerants that can be used as the fluoroolefin in the present invention. As described in paragraph 10 by Leck et al., representative unsaturated fluorocarbon refrigerants or heat storage fluids include 1,2,3,3,3-pentafluoro-1-propene, 1,1,3,3,3-pentafluoro-1-propene, 1,1,2,3,3-pentafluoro-1-propene, 1,2,3,3-tetrafluoro-1-propene, 2,3,3,3-tetrafluoro-1-propene, 1,3,3,3-tetrafluoro-1-propene, 1,1 ,3,3-tetrafluoro-1-propene, 1,2,3,3-tetrafluoro-1-propene, 2,3,3-trifluoro-1-propene, 3,3,3-trifluoro-1-propene, 1,1,2-trifluoro-1-propene, 1,1,3-trifluoro-1-propene, 1,2,3-trifluoro-1-propene, 1,3,3-trifluoro-1-propene, 1,1,1,2,3,4,4,4-octafluoro-2-butene, 1,1,2,3,3,4,4,4-octafluoro-1-butene, 1 ,1,1,2,4,4,4-Heptafluoro-2-butene, 1,2,3,3,4,4,4-Heptafluoro-1-butene, 1,1,1,2,3,4,4-Heptafluoro-2-butene, 1,3,3,3-Tetrafluoro-2-(trifluoromethyl)-2-propene, 1,1,3,3,4,4,4-Heptafluoro-1-butene, 1,1,2,3,4,4,4-Heptafluoro-1-butene, 1,1,2,3,3,4,4-Heptafluoro-1-butene, 2,3,3,4,4,4-Hexafluoro- 1-butene, 1,1,1,4,4,4-hexafluoro-2-butene, 1,3,3,4,4,4-hexafluoro-1-butene, 1,2,3,4,4,4-hexafluoro-1-butene, 1,2,3,3,4,4-hexafluoro-1-butene, 1,1,2,3,4,4-hexafluoro-2-butene, 1,1,1,2,3,4-hexafluoro-2-butene, 1,1,1,2,3,3-hexafluoro-2-butene, 1,1,1,3,4,4-hexafluoro-2-butene, 1,1,2,3,3,4-Hexafluoro-1-butene, 1,1,2,3,4,4-hexafluoro-1-butene, 3,3,3-trifluoro-2-(trifluoromethyl)-1-propene, 1,1,1,2,4-pentafluoro-2-butene, 1,1,1,3,4-pentafluoro-2-butene, 3,3,4,4,4-pentafluoro-1-butene, 1,1,1,4,4-pentafluoro-2-butene, 1,1,1,2,3-pentafluoro-2-butene, 2,3,3,4,4-pentafluoro-1-butene, 1,1,2,4,4-pentafluoro-2-butene, 1, 1,2,3,3-pentafluoro-1-butene, 1,1,2,3,4-pentafluoro-2-butene, 1,2,3,3,4-pentafluoro-1-butene, 1,1,3,3,3-pentafluoro-2-methyl-1-propene, 2-(difluoromethyl)-3,3,3-trifluoro-1-propene, 3,3,4,4-tetrafluoro-1-butene, 1,1,3,3-tetrafluoro-2-methyl-1-propene, 1,3,3,3-tetrafluoro-2-methyl-1-propene, 2-(difluoromethyl)-3,3-difluoro-1propene, 1,1, 1,2-tetrafluoro-2-butene, 1,1,1,3-tetrafluoro-2-butene, 1,1,1,2,3,4,4,5,5,5-decafluoro-2-pentene, 1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene, 1,1,1,4,4,4-hexafluoro-2-(trifluoromethyl)-2-butene, 1,1,1,2,4,4,5,5,5-nonafluoro-2-pentene, 1,1,1,3,4,4,5,5,5-nonafluoro-2-pentene, 1,2,3,3,4,4,5,5,5-nonafluoro-1-pentene, 1,1, 3,3,4,4,5,5,5-nonafluoro-1-pentene, 1,1,2,3,3,4,4,5,5-nonafluoro-1-pentene, 1,1,2,3,4,4,5,5,5-nonafluoro-2-pentene, 1,1,1,12,3,4,4,5,5-nonafluoro-2-pentene, 1,1,1,2,3,4,5,5,5-nonafluoro-2-pentene, 1,2,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene, 1,1,2,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene, 1,1,1,4,4,4-Hexafluoro-3-(trifluoromethyl)-2-butene, 1,1,3,4,4,4-hexafluoro-3-(trifluoromethyl)-1-butene, 2,3,3,4,4,5,5,5-octafluoro-1-pentene, 1,2,3,3,4,4,5,5-octafluoro-1-pentene, 3,3,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene, 1,1,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene, 1,3,4,4,4-pentafluoro-3-(trifluoromethyl)-1-butene, 1 ,1,4,4,4-pentafluoro-2-(trifluoromethyl)-1-butene, 1,1,1,4,4,5,5,5-octafluoro-2-pentene, 3,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene, 3,3,4,4,5,5,5-heptafluoro-1-pentene, 2,3,3,4,4,5,5-heptafluoro-1-pentene, 1,1,3,3,5,5,5-heptafluoro-1-pentene, 1,1,1,2,4,4,4-heptafluoro-3-methyl-2-butene, 2,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene 1,4,4,4-tetrafluoro-3-(trifluoromethyl)-1-butene, 1,4,4,4-tetrafluoro-3-(trifluoromethyl)-2-butene, 2,4,4,4-tetrafluoro-3-(trifluoromethyl)-2-butene, 3-(trifluoromethyl)-4,4,4-trifluoro-2-butene, 3,4,4,5,5,5-hexafluoro-2-pentene, 1,1,1,4,4,4-hexafluoro-2-methyl-2-butene, 3,3,4,5,5,5-hexafluoro-1-pentene, 4,4,4-trifluoromethyl 1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene, 1,1,2,3,3,4,4,5,5,6,6,6-dodecafluoro-1-hexene, 1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3-hexene, 1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene, 1,1,1,4,4,5,5,5-octafluoro-2-trifluoromethyl-2-pentene, 1,1,1,3,4,5,5,5-octafluoro-4-(trifluoromethyl)-2-pentene, 1,1,1,4,5,5,5-heptafluoro-4-(trifluoromethyl)-2-pentene, 1,1,1,4,4,5,5,6,6,6-decafluoro-2-hexene, 1,1,1,2,2,5,5,6,6,6-decafluoro-3-hexene, 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene, 4,4,4-trifluoro-3,3-bis(trifluoromethyl)-1-butene, 1,1,1,4,4,4-hexafluoro-3-methyl-2-(trifluoromethyl)-2-butene, 2,3,3,5,5,5-hexafluoro-4-(trifluoromethyl)- 1-Pentene, 1,1,1,2,4,4,5,5,5-nonafluoro-3-methyl-2-pentene, 1,1,1,5,5,5-hexafluoro-4-(trifluoromethyl)-2-pentene, 3,4,4,5,5,6,6,6-octafluoro-2-hexene, 3,3,4,4,5,5,6,6-octafluoro-2-hexene, 1,1,1,4,4-pentafluoro-2-(trifluoromethyl)-2-pentene, 4,4,5,5,5-pentafluoro-2-(trifluoromethyl)-1-pentene, 3,3,4,4,5,5,5-heptafluoro-2 -Methyl-1-pentene, 1,1,1,2,3,4,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene, 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-2-heptene, 1,1,1,3,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene, 1,1,1,2,4,4,5,5,6,6,7,7,7-tridecafluoro-2-heptene, 1,1,1,2,2,4,5,5,6,6,7,7,7-tridecafluoro-3-heptene, 1,1,1,2,2,3,5,56,6,7 ,7,7-tridecafluoro-3-heptene, 4,4,5,5,6,6,6-heptafluoro-2-hexene, 4,4,5,5,6,6,6-heptafluoro-1-hexene, 1,1,1,2,2,3,4-heptafluoro-3-hexene, 4,5,5,5-tetrafluoro-4-(trifluoromethyl)-1-pentene, 1,1,1,2,5,5,5-heptafluoro-4-methyl-2-pentene, 1,1,1,3-tetrafluoro-2-(trifluoromethyl)-2-pentene, 1,2,3,3,4,4-hexafluorocyclobutene, 3,3,4,4-tetrafluorocyclobutene, 3,3,4,4,5,5-hexafluorocyclopentene, 1,2,3,3,4,4,5,5-octafluorocyclopentene, 1,2,3,3,4,4,5,5,6,6-decafluorocyclohexene, 1,1,1,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)-2-pentene, pentafluoroethyl trifluorovinyl ether, trifluoromethyl trifluorovinyl ether, or any combination thereof.

[0040] Additionally, one or more non-low GWP refrigerant components, including a refrigerant moiety, may be present. Minor et al. (U.S. Patent Application Publication No. 2007 / 0289317, incorporated herein by reference) further lists examples of saturated and unsaturated fluorocarbon refrigerants that can be used as the fluoroalkane in the present invention. As described in paragraph 81 of Minor et al., representative hydrofluorocarbons can be represented by the formula CxH2x+2yFy or CxH2xyFy, where x can be equal to 3 to 8 and y can be equal to 1 to 17. The hydrofluorocarbons can be linear, branched, or cyclic, saturated or unsaturated compounds having from about 3 to 8 carbon atoms. Without limitation, representative fluoroalkanes that can be used include 1,1,2,2,3-pentafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,3-trifluoropropane, 1,1,3-trifluoropropane, 1,3-difluoropropane, 2-(difluoromethyl)-1,1,1,2,3,3-hexafluoropropane, 1,1,2,2,3,3,4,4-octafluorobutane, 1,1,1,2,2,4-hexafluorobutane, 1,1,1,3,3-pentafluoropropane, as described in paragraphs 47-78 of Minor et al. Fluorobutane, 1,1-difluorobutane, 1,3-difluoro-2-methylpropane, 1,2-difluoro-2-methylpropane, 1,2-difluorobutane, 1,3-difluorobutane, 1,4-difluorobutane, 2,3-difluorobutane, 1,1,1,2,3,3,4,4-octafluoro-2-(trifluoromethyl)butane, 1,1,1,2,2,3,3,4,4,5,5-undecafluoropentane, 1,1,1,2,2,3,4,5,5,5-decafluoropentane, and 1,1,1,2,2,3,3,5,5,5-decafluoropentane.

[0041] The GWP of the refrigerant or refrigerant blend portion of the invention will be less than 300, specifically less than 150 GWP, more specifically less than 75 GWP, and ideally less than 5 GWP. It is possible to use refrigerants with a GWP<1.

[0042] The minimum ignition energy (MIE) of the refrigerant portion of the blend, as measured by ASTM E-582, is at least 300 MJ / kg, preferably greater than 1,000 MJ / kg, more specifically between 1,000 MJ / kg and 5,000 MJ, and even more specifically at least 5,000 MJ / kg. The heat of combustion, as calculated by American Society of Heating, Refrigeration and Air-conditioning Engineers (ASHRAE) Standard 34, should be less than 19,000 kJ / kg, more specifically between 8 and 12 kJ / kg, and even more specifically between 9.5 and 11.5 kJ / kg. The lower flammability limit of the refrigerant portion at 21°C, as measured by ASTM E-681, may be practically non-flammable. Alternatively, if the refrigerant portion has a flammability limit, the lower flammability limit may be at least 5% by volume, more specifically at least 6% by volume, and even more specifically at least 6.2% by volume, as measured by ASTM E-681.

[0043] The resulting overall composition, i.e., the lubricants and refrigerants described herein, may be "post-added" to an A / C system and advantageously has relatively low corrosivity, such that metals (e.g., aluminum, copper, or iron) that are part of the A / C system that come into contact with the composition experience less corrosion. Furthermore, after 14 days of testing at 175°C, there was no tarnish on the steel, no coating or visible corrosion on the metal coupons, and no deposits or agglomerates formed during the test.

[0044] The relatively low corrosivity of the lubricant / refrigerant composition may be such that the refrigerant composition portion advantageously exhibits one or any combination of the following properties: Total acid number after aging for 14 days at 175°C according to ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems" is less than 3.3 mg KOH / g, less than 1.5 mg KOH / g, specifically less than 1.0 mg KOH / g, as measured in accordance with ASTM D664-01; and for aluminum, copper, and carbon steel coupons, total halide concentration (e.g., fluoride ion concentration) after aging for 14 days at 175°C according to ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems" is less than about 100 ppm, preferably less than 50 ppm, and ideally less than 10 ppm. For aluminum, copper, and iron metal coupons, the total organic acid concentration is less than about 300 ppm after aging at 175°C for 14 days according to ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems," as determined by ion chromatography.

[0045] Additives that can improve refrigerant and A / C life, as well as compressor durability, are desirable. In one aspect of the present invention, the refrigerant containing compositions of the present invention are used to introduce lubricants and other additives, such as a) acid scavengers, b) performance enhancers, and c) flame suppressants, into A / C systems.

[0046] Acid Scavenger The acid scavenger can include a siloxane, an activated aromatic compound, or a combination of both. Serrano et al. (paragraph 38), incorporated herein by reference, discloses that the siloxane can be any molecule having siloxy functionality. The siloxane can include alkylsiloxanes, arylsiloxanes, or siloxanes containing a mixture of aryl and alkyl substituents. For example, the siloxane can be an alkylsiloxane, including a dialkylsiloxane or a polydialkylsiloxane. Preferred siloxanes include groups having an oxygen atom bonded to two silicon atoms, i.e., the structure SiOSi. For example, the siloxane can be a siloxane of formula IV: R1[Si(R2R3)4O]nSi(R2R3)R4, where n is 1 or greater. Siloxanes of formula IV preferably have n equal to 2 or greater, more preferably 3 or greater (e.g., about 4 or greater). Siloxanes of Formula IV preferably have n of about 30 or less, more preferably about 12 or less, and most preferably about 7 or less. Preferably, the R4 group is an aryl or alkyl group. Preferably, the R2 group is an aryl or alkyl group, or a mixture thereof. Preferably, the R3 group is an aryl or alkyl group, or a mixture thereof. Preferably, the R4 group is an aryl or alkyl group. Preferably, R1, R2, R3, R4, or any combination thereof is not hydrogen. The R2 groups in a molecule can be the same or different. Preferably, the R2 groups in a molecule are the same. The R2 groups in a molecule can be the same or different from the R3 groups. Preferably, the R2 and R3 groups in a molecule are the same. Preferred siloxanes include siloxanes of Formula IV, wherein R1, R2, R3, R4, R5, or any combination thereof, is a methyl group, an ethyl group, a propyl group, or a butyl group, or any combination thereof. Exemplary siloxanes that can be used include hexamethyldisiloxane, polydimethylsiloxane, polymethylphenylsiloxane, dodecamethylpentasiloxane, decamethylcyclopentasiloxane, decamethyltetrasiloxane, octamethyltrisiloxane, or any combination thereof.

[0047] Paragraph

[0039] of Serrano et al., incorporated by reference, states that in one aspect of the present invention, the siloxane is an alkylsiloxane containing from about 1 to about 12 carbon atoms, such as hexamethyldisiloxane. The siloxane may also be a polymer, such as polydialkylsiloxane, where the alkyl groups are methyl, ethyl, propyl, butyl, or any combination thereof. Suitable polydialkylsiloxanes have molecular weights of from about 100 to about 10,000. Highly preferred siloxanes include hexamethyldisiloxane, polydimethylsiloxane, and combinations thereof. The siloxane may consist essentially of polydimethylsiloxane, hexamethyldisoloxane, or combinations thereof.

[0048] An activated aromatic compound can be any aromatic molecule or mixture thereof that has been activated for Friedel-Crafts addition. An activated aromatic molecule for Friedel-Crafts addition is defined as any aromatic molecule capable of addition with a mineral acid. In particular, aromatic molecules capable of addition with a mineral acid, either in the present environment (AC system) or during the ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems" thermal stability test. Such molecules or compounds are typically activated by replacing a hydrogen atom on the aromatic ring with one of the following groups: NH, NHR, NR, ADH, AD, NHCOCH, NHCOR, OCH, OR, CH, CH, R, or CH, where R is a hydrocarbon (preferably a hydrocarbon containing from about 1 to about 100 carbon atoms). The activated aromatic molecule can also be an alcohol or ether in which an oxygen atom (i.e., the oxygen atom of an alcohol or ether group) is directly attached to the aromatic group. The activated aromatic molecule may be an amine in which the nitrogen atom (i.e., the nitrogen atom of the amine group) is directly bonded to an aromatic group. For example, the activated aromatic molecule may have the formula ArXRn, where X is O (i.e., oxygen) or N (i.e., nitrogen), where n:1 when X:O and n:2 when X:N, and Ar is an aromatic group (i.e., a CH group), and R may be H or a carbon-containing group, where n:2, the R groups may be the same or different. For example, R may be H (i.e., hydrogen), Ar, an alkyl group, or any combination thereof. Exemplary activated aromatic molecules that may be used in refrigerant compositions based on the teachings herein include diphenyl oxide (i.e., diphenyl ether), methyl phenyl ether (e.g., anisole), ethyl phenyl ether, butyl phenyl ether, or any combination thereof. One highly preferred aromatic molecule activated for Friedel-Crafts addition reactions is diphenyl oxide.

[0049] Incorporated by reference from paragraph

[0045] of Serrano et al., the acid scavenger (e.g., activated aromatic compound, siloxane, or both) may be present at any concentration that results in a relatively low total acid number, a relatively low total halide concentration, a relatively low total organic acid concentration, or any combination thereof. The acid scavenger is preferably present at a concentration greater than about 0.0050 wt.%, more preferably greater than about 0.05 wt.%, and even more preferably greater than about 0.1 wt.% (e.g., greater than about 0.5 wt.%), based on the total weight of the refrigerant composition. The acid scavenger is preferably present at a concentration less than about 3 wt.%, more preferably less than about 2.5 wt.%, and most preferably less than about 2 wt.% (e.g., less than about 1.8 wt.%), based on the total weight of the refrigerant composition.

[0050] Additional examples of acid scavengers that may be included in, and preferably excluded from, the refrigerant composition include those described by Kaneko (U.S. Patent Application No. 11 / 575,256, published as U.S. Patent Application Publication No. 2007 / 0290164, paragraph 42, which is expressly incorporated herein by reference), and by Singh et al. (U.S. Patent Application No. 11 / 250,219, published as U.S. Patent Application No. 20060116310, paragraphs 34-42, which are expressly incorporated herein by reference), such as one or more of phenyl glycidyl ether, alkyl glycidyl ethers, alkylene glycol glycidyl ethers, cyclohexene oxide, otolenoxides, or epoxy compounds such as epoxidized soybean oil.

[0051] Performance Enhancers Preferred additives include those described in U.S. Patent Nos. 5,152,926 and 4,755,316, which are incorporated herein by reference. Specifically, preferred extreme pressure additives include a mixture of (A) tolyltriazole or a substituted derivative thereof, (B) an amine (e.g., Jeffamine M-600), and (C) a third component that is (i) an ethoxylated phosphate ester (e.g., Antara LP-700 type), or (ii) an alcohol phosphate (e.g., ZELEC 3337 type), or (iii) a zinc dialkyldithiophosphate (e.g., Lubrizol 5139, 5604, 5178, or 5186 type), or (iv) a mercaptobenzothiazole, or (v) a 2,5-dimercapto-1,3,4-triadiaZole derivative (e.g., Curvan 826), or a mixture thereof. Additional examples of additives that can be used are described in US Pat. No. 5,976,399 (Schnur, 5:12-6:51, incorporated herein by reference).

[0052] Acid number is measured in mgKOH / g according to ASTM D664-01. Total halide, fluoride, and total organic acid concentrations are measured by ion chromatography. Chemical stability of refrigerant systems is measured according to ASHRAE 97:2007, "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems." Lubricant viscosity is tested at 40°C according to ASTM D-7042.

[0053] Mouli et al. (WO 2008 / 027595) teach the use of alkylsilanes as stabilizers in fluoroolefin-containing refrigerant compositions. Phosphates, phosphites, epoxides, and phenolic additives have also been used in certain refrigerant compositions. These are described, for example, by Kaneko (U.S. Patent Application No. 11 / 575,256, published as U.S. Patent Application No. 2007 / 0290164) and Singh et al. (U.S. Patent Application No. 11 / 250,219, published as U.S. Patent Application No. 2006 / 0116310). All of these above applications are expressly incorporated herein by reference.

[0054] Flame suppressant Preferred flame suppressants include those described in patent application "Compositions containing fluorine substituted olefins" (Canadian Patent No. 2557873A1), which is incorporated by reference, along with fluorinated products such as HFC-125 and / or Krytox® lubricants, which are described in patent application "Compositions comprising fluoroolefins and uses thereof" (WO2009018117A1), which is also incorporated by reference.

[0055] Compatibility / Package Stability While HFO-1234yf has generally been found to be compatible with polyalkylene glycol (PAG)-type lubricants when used as the primary refrigerant in vehicle A / C systems, not all PAG lubricants possess the necessary miscibility range, thermal stability, material compatibility, and wetting level, among other properties, that make them suitable for use with HFO-1234yf in automotive A / C systems. Therefore, the compositions of the present invention are substantially free of PAG lubricants lacking the above-mentioned properties. By "substantially free," we mean that when the compositions of the present invention contain HFO-1234yf, the compositions contain less than 5 wt. %, typically less than 3 wt. %, and in some cases less than 0.5 wt. % of the following: doubly end-capped PAG ND-8; single end-capped PAG Dow RL244. The amount of lubricant typically used in A / C systems ranges from about 5 to about 10 wt. % of the A / C refrigerant. For example, if the A / C refrigerant charge is 600g, then 60g of lubricant is used (90% refrigerant / 10% lubricant by weight). However, because the refrigerant is used to transport the lubricant through the A / C system, the amount of PAG oil used in conjunction with the refrigerant will be relatively large, approximately 50-80% lubricant / 20-50% refrigerant by weight (e.g., about 60-65% lubricant by weight).

[0056] The primary component of the compositions of the present invention may comprise a lubricating oil, while the secondary component(s) comprise a refrigerant with a low amount (0-5 wt%) of some additive that improves desired performance characteristics, i.e., the refrigerant is used to carry or transport the liquid lubricating oil and additives into the A / C system.

[0057] Due to storage and use conditions, lubricants and refrigerants must be mutually miscible over a much larger range. There are many cities around the world that experience temperatures above 37.5°C. Furthermore, it is expected that lubricant / oil compositions will be stored in relatively hot warehouses or used in hot garages where temperatures may reach 37.5°C for periods exceeding 70 days.

[0058] It is also envisioned that the product could be used during the winter months following a serious vehicle system failure, such as a frontal collision.

[0059] The lubricant / refrigerant compositions are stable at temperatures of about -20, -30, and even -40°C, which may aid in storing the compositions for extended periods of time, such as 5 days at temperatures of -20°C.

[0060] Surprisingly, the compositions of the present invention maintain miscibility over a wide range of temperature and pressure conditions (e.g., a 20-50 wt. % refrigerant / 50-80 wt. % lubricant composition that is miscible in a sealed container over temperatures ranging from -18°C to 37°C and pressures from 160 kPa to 945 kPa). PAG lubricant / refrigerant miscibility is tested using ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems" by placing a predetermined amount of lubricant and refrigerant (see table below) into a sealed tube. The sealed tube is then placed in a water bath to determine whether the mixture is miscible over the temperature range. The test is conducted in two segments, with a 24-hour period between each segment to allow the tube to return to room temperature before starting the next segment. The low-temperature segment begins at room temperature and gradually decreases the temperature in 5°C increments down to -50°C, holding each temperature for 10 minutes, with visual observations recorded at each temperature hold. The high temperature segment begins at room temperature and the temperature is tested in 5°C increments, gradually increasing to 90°C or the critical temperature of the refrigerant, again holding at each temperature for 10 minutes, with visual observations recorded at each temperature hold.

[0061] The thermal stability of PAG lubricant / refrigerant compositions was evaluated using ASHRAE 97:2007, "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems." The lubricant / refrigerant system was also placed in a sealed tube containing metal (Al, Cu, carbon steel) coupons and held at 175°C for two weeks. Results showed that the PAG lubricant / low GWP refrigerant(s) were thermally stable at high temperatures, indicating that the compositions would not decompose during storage. There was no haze on the steel, no coating or visible corrosion was present on the metal coupons, and no fluoride ions or acids were produced. No deposits or agglomerates formed during the test. No color change occurred in the refrigerant / lubricant system.

[0062] The unexpected result was that lubricants previously described as "compatible with HFO-1234yf" were not miscible across the entire miscibility range. PAG lubricants known as 46 cSt type PAG oils, known by the following trademarks: "ND-12," "SP-A2," "PS-D1," and "FD46XG," were found to meet all the desired criteria.

[0063] Without wishing to be bound by any theory or explanation, it is believed that the range of lubricant / lubricant miscibility changes as the refrigerant concentration increases and becomes a major portion of the composition. For example, 30% lubricant / 70% refrigerant by weight is the minimum for use in an A / C system, but lacks sufficient miscibility to allow the lubricant to be transported through the system with the refrigerant.

[0064] A conventional PAG lubricant (Idemitsu® ND-8) used in conjunction with R-134a did not have the same miscibility range or thermal stability as R-1234yf (an unsaturated, low-GWP refrigerant). After two weeks of testing at 175°C according to the ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems" sealed tube test, it was found that 1234yf / ND-8 produced higher than desired TAN values ​​(>1.0 mg KOH / g) and higher halide values ​​(>100 ppm). Thus, only the selected dual-end-capped PAG was found to have the desired miscibility and thermal stability with the low-GWP HFO-1234yf refrigerant.

[0065] Examples of low GWP refrigerant / PAG oil compositions and miscibility ranges are shown in Table 2, where the top of the table indicates the use of the product in an A / C system and the bottom of the table indicates manufacturing and storage temperatures ("M" in the table means miscible and "N" means immiscible).

[0066] [Table 2]

[0067] One aspect of the present invention relates to a method for introducing lubricant into an A / C system. In this method, a refrigerant is used to transport the lubricant and / or lubricant additive package through the A / C hose without substantially adhering to the hose, thereby ensuring that more lubricant or lubricant / additive package is introduced into the A / C system (e.g., using a manual injector or manual pump can result in lubricant adhering to the hose connecting the A / C system). Because the refrigerant transports the lubricant and conveys it into the A / C system, using a refrigerant to transfer the lubricant into the system ensures that more lubricant is introduced into the A / C system compared to manual or pump injectors. The lubricant or lubricant / additive and refrigerant are co-packaged in a conventional container or can, provided that the lubricant and refrigerant are miscible. Upon exiting the canister, the refrigerant changes state from a compressed liquefied gas to a refrigerant gas. During this process, the refrigerant, which is miscible with the lubricant, atomizes the lubricant or lubricant / additive mixture and carries the lubricant or lubricant / additive mixture further along the hose and into the A / C system before the lubricant or lubricant / additive mixture can precipitate on the walls of the A / C refill hose.

[0068] Another aspect of the present invention relates to a method for introducing environmentally friendly refrigerants into an A / C system, in which the same delivery methods as above were used to introduce refrigerants / lubricants with or without additive packages into the system, with the same positive results as above.

[0069] The compositions of the present invention (lubricant or lubricant / additive and refrigerant) can be packaged in small, sealed cans, typically 8 oz or less, more typically 3-6 oz, and even more specifically 3-4 oz. The compositions of the present invention should be packaged in small cans with pierceable or self-sealing can tops that can be connected to a vehicle's A / C system using a typical aftermarket refrigerant refill hose.

[0070] In one embodiment, because this product is intended for use in a low-GWP A / C system containing HFO-1234yf, the fitting used on the top of the can should be left-hand threaded and compatible with a male CGA166 type connection. The construction of this type of hose used to transport this product from the can to the vehicle's A / C system should comply with the SAE J2888 standard. The hose should have two different fittings. One end of the A / C refill hose should be connectable to a small can and have either a piercing needle or a plunger-type mechanism, sometimes called a can tap, capable of releasing the product contained within the small can. The fitting that connects to the can will be a female CGA166 type fitting. The other end of the refill hose should have an SAE J639 low-side quick-connect coupler specified for HFO-1234yf and be attachable to the vehicle's A / C system via a low-side service port.

[0071] To deliver the composition of the present invention into an A / C system, first thoroughly shake the can containing the lubricant or lubricant / additive and refrigerant. Start the vehicle's engine and then set the A / C system to maximum cooling. Then, attach the aftermarket refill hose described above to the can. The other end of the hose should be connected to the vehicle's A / C low-side service port. When ready to begin dispensing the product, use the needle or plunger mechanism to release the contents of the can. Shake the can slightly from side to side to assist in releasing the contents. This process should take approximately 10 to 15 minutes.

[0072] The instant composition can be used to add a lubricant or lubricant / additive to an A / C system at temperatures of about 0° C. to about 40° C., more specifically, the composition can be used at temperatures of about 10° C. to about 35° C., and even more specifically, at temperatures of about 15° C. to about 30° C. The compositions of the present invention can be stored at temperatures as low as about −20° C. to as high as about 40° C. to about 45° C., but typically are stored at temperatures of about 10° C. to about 35° C., more specifically, at temperatures of about 15° C. to about 30° C. Typically, when connected to an A / C system, the compositions of the present invention are delivered to the A / C system at a pressure of about 315 kPa to about 435 kPa, or more specifically, about 330 kPa to about 410 kPa, or even more specifically, about 360 kPa to about 400 kPa.

[0073] Another aspect of the present invention relates to a system for introducing the composition of the present invention into a thermal management system, such as an automotive A / C system. Referring now to FIG. 1, a system (100) for introducing a lubricant using the composition of the present invention into an automotive A / C system is shown. The system for delivering the composition of the present invention to an automotive A / C system includes a container (110) containing the composition, a compressor (120), a condenser (130), a dryer (140), an expansion valve (150), and an evaporator (160). The system (100) further includes a low-side service port (170) and a high-side service port (180). The container (110) or can containing the composition of the present invention is connected to the low-side service port (170) of the compressor (120) via a hose (190). The hoses 190 and piping 195 connecting the compressor, condenser, dryer, expansion valve, and evaporator are constructed and assembled using materials and methods known in the art.

[0074] A further aspect of the present invention relates to a kit. Referring now to Figure 2, a kit (200) is shown comprising a container (210) having a container coupler (215) and containing a composition of the present invention, and a manual dispenser (220) for controlling the flow of the composition into an A / C system (230). The dispenser (220) further comprises a dispenser coupler (240) configured to attach to the container coupler (215) to facilitate transfer of the composition of the present invention into the A / C system (230). A hose (250) connects the dispenser (220) to the A / C system (230) and is configured to convey the composition from the dispenser (220) to the A / C system (230).

[0075] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover non-exclusive inclusions. For example, a composition, process, method, article, or device that comprises listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent in such composition or process, method, article, device, etc. Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive or, not an exclusive or. For example, condition A or B can be satisfied by any one of the following: A is true (or present) and B is false (or absent), A is false (or absent) and B is true (or present), and both A and B are true (or present).

[0076] The transitional phrase "consisting of" excludes any unspecified element, step, or ingredient. In the case of a claim, such a phrase excludes from the claim the inclusion of materials other than those recited, except for impurities normally associated with the material. When the phrase "consisting of" appears within a clause in the body of a claim rather than immediately following the preamble, the phrase limits only the elements set forth in that clause and does not exclude other elements from the claim as a whole.

[0077] The transitional phrase "consisting essentially of" is used to define compositions, methods, and compositions that include materials, steps, features, ingredients, or elements in addition to those literally disclosed, provided that these additionally included materials, steps, features, ingredients, or elements materially affect the basic and novel characteristic(s) of the claimed invention, particularly the mode of action for achieving the desired results of any process of the invention. The term "consisting essentially of" occupies intermediate ground between "comprising" and "consisting of."

[0078] It should be readily understood that where applicants have defined an invention or a portion thereof in open-ended terms such as "comprising," the description should be construed to also include inventions using the terms "consisting essentially of" or "consisting of" (unless otherwise expressly stated).

[0079] Additionally, the use of "a" or "an" is employed to describe elements and components described herein. This is merely for convenience and to give a general sense of the scope of the invention. This description should be interpreted to include one or at least one, and the singular also includes the plural unless it is clear that a different meaning is intended.

[0080] While certain aspects, embodiments, and principles have been described above, it will be understood that this description is for illustrative purposes only and is not intended to limit the scope of the invention or the appended claims.

Claims

1. 50 to 80 wt. % of a doubly end-capped polyalkylene glycol (PAG) lubricant, 20 to 50 wt. % of an HFO-1234yf refrigerant exhibiting a global warming potential (GWP) of less than 100, and 1 to 5 wt. % of an acid scavenger; The lubricating oil has the following properties: (a) a total acid number of up to 0.1 mg KOH / g, as measured in accordance with ASTM D974; (b) A moisture content of 500 ppm or less, as determined in accordance with ASTM E284; or (c) a viscosity of 40 to 50 cSt measured at 40°C according to ASTM D445 At least one of the following is satisfied: The total amount of the doubly end-capped polyalkylene glycol (PAG) lubricant, the HFO-1234yf refrigerant exhibiting a global warming potential (GWP) of less than 100, and the acid scavenger is up to 100%. composition.

2. 10. The composition of claim 1, wherein the acid scavenger comprises at least one member selected from the group consisting of hexamethyldisiloxane, polydimethylsiloxane, polymethylphenylsiloxane, dodecamethylpentasiloxane, decamethylcyclopentasiloxane, decamethyltetrasiloxane, or octamethyltrisiloxane.

3. further comprising 1 to 5 wt. % of a performance enhancer, said performance enhancer being an alkyl silane, a phosphate, a phosphite, an epoxide, a phenolic additive, or (A) tolyltriazole or a substituted derivative thereof; (B) an amine; (C) a third component which is (i) an ethoxylated phosphate ester, (ii) an alcohol phosphate, (iii) a zinc dialkyldithiophosphate, (iv) a mercaptobenzothiazole, (v) a 2,5-dimercapto-1,3,4-tridiazole derivative, or a mixture thereof; and 3. The composition of claim 1 or 2, comprising a mixture of:

4. 1 to 15 wt. % of a doubly end-capped polyalkylene glycol (PAG) lubricant and 85 to 99 wt. % of an HFO-1234yf refrigerant exhibiting a global warming potential (GWP) of less than 100; The lubricating oil has the following properties: (a) a total acid number of up to 0.1 mg KOH / g, as measured in accordance with ASTM D974; (b) A moisture content of 500 ppm or less, as determined in accordance with ASTM E284; or (c) a viscosity of 40 to 50 cSt measured at 40°C according to ASTM D445 Fulfilling A composition comprising up to 100% of said doubly end-capped polyalkylene glycol (PAG) lubricant and said HFO-1234yf refrigerant exhibiting a global warming potential (GWP) of less than 100.

5. The composition of any one of claims 1 to 4, further comprising 1 to 10 wt% of a flame suppressant.

6. A container configured to deliver the composition of any one of claims 1 to 5 into a vehicle air conditioning system.

7. 7. The container of claim 6, wherein the pressure inside the container is between 160 kPa and 945 kPa.

8. 8. A system for delivering the composition from the container of claim 6 or 7 to a motor vehicle air conditioning system, comprising the container, a compressor, a condenser, a dryer, an expansion valve, and an evaporator.

9. 6. A system for delivering the composition of any one of claims 1 to 5 from a container to an automotive air conditioning system, the system comprising: the container containing the composition of any one of claims 1 to 5; a compressor; a condenser; a dryer; an expansion valve; and an evaporator.

10. 8. A kit comprising the container of claim 6 or 7, a manual dispenser for controlling the flow of the composition into an air conditioning system, and a hose for conveying the composition to the air conditioning system.

11. 6. A kit comprising a container containing the composition of any one of claims 1 to 5, a manual dispenser for controlling the flow of the composition into an air conditioning system, and a hose for conveying the composition to the air conditioning system.

12. The composition further comprises 1 to 5 wt. % of a performance enhancer, wherein the performance enhancer is selected from the group consisting of alkyl silanes, phosphates, phosphites, epoxides, phenolic additives, and the like. (A) tolyltriazole or a substituted derivative thereof; (B) an amine; (C) a third component which is (i) an ethoxylated phosphate ester, (ii) an alcohol phosphate, (iii) a zinc dialkyldithiophosphate, (iv) a mercaptobenzothiazole, (v) a 2,5-dimercapto-1,3,4-tridiazole derivative, or a mixture thereof; and The composition of claim 4 comprising a mixture of:

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