Compositions, systems, and methods for introducing PAG lubricants or refrigerants into air conditioning or systems using refrigerants or refrigerant blends with lower or lower GWP.

Abstract

There is a need for a method of quickly and conveniently delivering lubricating oil to the A / C system without using manual injectors. [Solution] Compositions, systems, and methods are disclosed for introducing lubricants and additives designed to work in conjunction with environmentally friendly refrigerants in vehicle thermal management systems, including passenger cabin air conditioning (A / C) systems. Also disclosed are methods for filling environmentally friendly systems, such as systems using HFO-1234yf, with lubricants and specific additives using environmentally desirable (low GWP) refrigerants or refrigerant blend compositions.

Description

Technical Field

[0001] The present invention generally relates to compositions, systems, and methods for introducing lubricants and additives designed to work in conjunction with environmentally friendly refrigerants in vehicle thermal management systems including passenger compartment 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 a lubricant and specific additives using an environmentally desirable (low GWP) refrigerant or refrigerant blend composition. The present invention further relates to methods for filling an environmentally friendly system, such as a system using HFO-1234yf, with a refrigerant containing a lubricant and specific additives.

Background Art

[0002] Since the mid-1990s, automotive air conditioning (A / C) systems have used the R-134a refrigerant for vapor compression cycles. Currently, due to environmental and social pressures, automotive manufacturers worldwide are transitioning to the low global warming potential (GWP) refrigerant HFO-1234yf (2,3,3,3-tetrafluoropropene) as the vehicle A / C refrigerant. In conventional vapor compression A / C systems, an A / C compressor circulates refrigerant within the A / C system to achieve cooling. For this reason, the A / C compressor is essential for the operation of the A / C system. The A / C compressor serves to pump the working fluid into the system as the heart of the A / C system. If the A / C compressor does not operate properly, the A / C system will not function.

[0003] To operate properly, an A / C compressor requires lubricating oil with the correct physical parameters (viscosity, humidity, TAN, etc.). The lubricating oil must circulate completely within the A / C system. The lubricating oil must be transported by the refrigerant from one part of the system to the next, and while inside the compressor, the lubricating oil must also be able to provide lubrication while simultaneously transporting the refrigerant from one part of the system to another. Therefore, mutual compatibility between the refrigerant and oil 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 filling process. The A / C system may require repair due to component failure (such as a ruptured hose or pipe) or a vehicle accident that impairs the A / C system. Generally, the automotive aftermarket parts market or service industry employs recovery, recycle, recharge, or "R / R / R" equipment to reinject / refill the refrigerant and lubricant into the A / C system after repair. However, current R / R / R equipment designed for use with HFO-1234yf, specifically under SAE J2843, section 8.9.5.1 of the above SAE standard (as incorporated herein by reference), cannot automatically inject lubricant into the system after repair by the R / R / R equipment. The lubricant must be injected either manually or mechanically. In each of these options, the lubricant is filled into an injector and then a hose is attached to the lower 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. Once the A / C compressor starts circulating, the installed injectors are directed to the open position, and lubricating oil is delivered 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 pump mechanism to pressurize the lubricating oil through a connected hose to the A / C service port. The lubricating oil is drawn into the system by the A / C compressor. During the delivery process, the lubricating oil may adhere to the walls of the hose, making it difficult to deliver a sufficient amount of lubricating oil to the system. Therefore, there is a need in the art for a method of quickly and conveniently delivering lubricating oil to the A / C system without using a manual injector.

[0006] It should also be noted that, in some cases, it may be advantageous to use this same transport method to employ a similar transport process for delivering refrigerants, refrigerants containing lubricating oils, or refrigerants containing other performance-enhancing additives into an A / C system. [Overview of the project] [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 a low-GWP HFO-1234yf automotive A / C system using a refill hose that is common in the A / C repair parts market. In a manual injector or manual pump, the flow of lubricant is controlled by the viscosity of the lubricant and the suction force 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 causing it to adhere to the hose, thereby ensuring that more lubricant or lubricant / additive package is introduced into the A / C system, and thus improving the flow of the material.

[0008] Using a manual injector or pump may result in lubricating oil adhering to the hoses connecting to the A / C system. Since refrigerant transports and delivers the lubricating oil into the A / C system, using refrigerant to transfer the lubricating oil into the system ensures that more lubricating oil is introduced into the A / C system compared to manual or pump injectors. The lubricating oil or lubricating oil / additive and refrigerant are co-packaged in conventional containers or cans under conditions where the lubricating oil and refrigerant are miscible. Upon discharge from the small container, the refrigerant component changes state from compressed liquefied gas to gas, while the oil component is atomized. During this process, the refrigerant, which is miscible with the lubricating oil, atomizes the lubricating oil or lubricating oil / additive mixture, further transporting the lubricating oil or lubricating oil / additive mixture along the hose into the A / C system before it can settle 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% by weight of PAG lubricating oil and about 20 to about 50% by weight of a low GWP refrigerant.

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

[0011] Another aspect 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 present invention relates to any of the above compositions, further comprising about 1 to 5% by weight of a performance enhancer.

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

[0014] One aspect of the present invention relates to a container for delivering any of the above-mentioned compositions 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 either the above-described composition or container.

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

[0019] Further aspects of the present invention include the above-described method, which 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-mentioned compositions, methods, and containers to an automotive A / C system comprising a container containing the composition, a compressor, a condenser, a dryer, an expansion valve, and an evaporator.

[0021] A further aspect of the present invention includes using the kit shown in Figure 2 to provide a composition used in any of the above compositions and methods.

[0022] Another aspect of the present invention relates to a composition comprising about 1 to about 15% by weight of PAG lubricating oil and about 85 to about 99% by weight of a low GWP refrigerant.

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

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

[0025] The various aspects and embodiments disclosed in this specification can be used alone or in various combinations with each other.

Brief Description of the Drawings

[0026] [Figure 1] It is a schematic diagram of the system for introducing the composition of the present invention into the A / C system. [Figure 2] It is a photograph of the kit for use in delivering the composition of the present invention from the container into the A / C system.

Modes for Carrying Out the Invention

[0027] The present invention generally relates to a composition comprising a lubricant and an additive designed to cooperate with environmentally friendly refrigerants. More specifically, the present invention relates to a composition for use in an A / C system, comprising about 50 to about 80% by weight, about 55 to about 70% by weight, or about 60 to about 65% by weight of PAG lubricant, about 0 to about 5% by weight of an additive, and about 20 to about 50% by weight, about 30 to about 45% by weight, or about 35 to about 40% by weight of a low GWP refrigerant or refrigerant blend, or consisting essentially of these.

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

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

[0030] Polyalkylene glycols used herein include compounds comprising two or more alkylene oxides, in which one or more of the ends are opened by a moiety (group) that does not contain an active hydrogen atom. Any alkylene oxide that promotes lubrication can be used together with ethylene oxide, with propylene oxide being preferred and more preferred. The end-capping portion can be any portion that does not interfere with lubrication or cooling. Preferred end-capping portions 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 monools having at least one hydroxyl group. Preferred alkylene glycols are single-end capped or double-end capped, with double capping being more preferred.

[0031] In a preferred embodiment, the lubricating oil is soluble in the vehicle A / C system refrigerant at temperatures ranging from about 0°C to about 100°C, more preferably from about 0°C to about 40°C, and more specifically from 5°C to 40°C. In another embodiment, high-temperature solubility is undesirable 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 greater than about 5 cSt, preferably greater than about 10 cSt, and most preferably greater than about 20 cSt (measured at 40°C according to ASTM D445). The lubricating oil may have a kinematic viscosity less than about 600 cSt, more preferably less than about 320 cSt, and most preferably less than about 210 cSt (measured at 40°C according to ASTM D445). Ideally, the lubricating oil has a kinematic viscosity of 40 to 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 (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 preferred properties of lubricating oils for use with the compositions of the present invention.

[0034] [Table 1]

[0035] Furthermore, the PAG lubricant used in this composition should have material compatibility with elastomers and plastics commonly used in vehicle A / C systems. The PAG lubricant used should have good material compatibility with elastomers 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 at 100°C for two weeks using ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems". Similarly, the PAG lubricant used should have good material compatibility with plastic materials, namely polyester, nylon, epoxy, polyethylene, terephthalate, and polyimide, as measured at 100°C for two weeks according to ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems". Plastics and elastomers used in combination with the above PAG lubricant and HFO-1234yf should have a weight increase of less than about 10%, less than about 8%, or less than about 7%, or a linear expansion 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 increase of less than 10%, or a linear expansion of less than 10%, or less than a hardness change in at least two properties, and preferably less than 10% in all three properties, as measured by durometer.

[0036] Several PAG lubricants have been found to possess the necessary miscibility with specific low GWP refrigerants, namely HFO-1234yf (available from The Chemours Company as Optone™ refrigerant), over a desired temperature range, have the desired lubricant viscosity, and possess the desired elastomer / plastic material compatibility. Specifically, PAG is known as 46cSt type PAG oil and is known by the following trademarks: “ND-12”, “SP-A2”, “PS-D1”, and “FD46XG”.

[0037] refrigerant The refrigerant portion of the mixture contains at least one hydrofluoroolefin (or more commonly, 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 0. The Intergovernmental Panel on Climate Change (IPCC) periodically reviews and defines the GWPs of fluorocarbons. The hydrofluoroolefin refrigerants embodied in this invention have a GWP of less than approximately 100 GWP, but are typically less than 10, and can even be reduced to 1 GWP. Particularly useful hydrofluoroolefins include HFO-1234yf. According to the UN's IPCC Fifth Assessment Report (AR5), HFO-1234yf has a GWP of less than 1.

[0038] The Global Warming Potential (GWP) is an index used to estimate the relative contribution to global warming caused by one kilogram of atmospheric emissions of a particular greenhouse gas compared to one kilogram of carbon dioxide emissions. GWP can be calculated for various time periods and reflects the atmospheric lifetime effect of a given gas. A GWP for a 100-year period is a commonly referenced value. For mixtures, a weighted average can be calculated based on the individual GWPs for each component.

[0039] Leck et al. (U.S. Patent Application Publication 2007 / 0187639, paragraph 10, incorporated herein by reference) further enumerate examples of unsaturated fluorocarbon refrigerants that can be used as fluoroolefins in the present invention. As described in paragraph 10 by Leck et al., typical 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, 1,1,2,3-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, 1,1,2,3,3,4,4-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-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-1-propene, 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, 1,1,1,4,4,4-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 Oromethyl)-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- Lifluoro-2-(trifluoromethyl)-1-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, 1,1,1,2,2,3,5,5,6,6,7 ,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,Examples include 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] Furthermore, one or more non-low GWP refrigerant components, including a refrigerant portion, may be present. Minor et al. (U.S. Patent Application Publication No. 2007 / 0289317, incorporated herein by reference) further enumerate examples of saturated and unsaturated fluorocarbon refrigerants that can be used as fluoroalkanes in the present invention. As described in paragraph 81 by Minor et al., a typical hydrofluorocarbon can be represented by the formula CxH2x+2yFy or CxH2xyFy, where x may be equal to 3 to 8 and y may be equal to 1 to 17. The hydrofluorocarbon may be a linear, branched, or cyclic saturated or unsaturated compound having about 3 to 8 carbon atoms. Without limitation, representative fluoroalkanes that can be used include, as described in paragraphs 47-78 by Minor et al., 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, and 1,1,1,3,3-pentafluoropropane. Examples include ulolobutane, 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 above 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 the refrigerant in such a way that GWP < 1.

[0042] The minimum ignition energy (MIE) of the refrigerant portion of the above 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, calculated according to 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 actually be non-flammable. Alternatively, if the refrigerant portion has a flammability limit, the lower flammability limit may be at least 5 vol% as measured by ASTM E-681, more specifically at least 6 vol%, and even more specifically at least 6.2 vol%.

[0043] The resulting overall composition, i.e., the lubricating oil and refrigerant described herein, may be “added later” to the A / C system and has the advantage of relatively low corrosivity, resulting in relatively less corrosion experienced by metals (e.g., aluminum, copper, or iron) that are part of the A / C system in contact with the composition. Furthermore, after testing at 175°C for 14 days, there was no tarnishing on the steel, no film or visible corrosion on the metal pieces, and no deposits or aggregates formed during the test.

[0044] The relatively low corrosiveness of the lubricating oil / refrigerant composition may favorably exhibit one or any combination of the following properties: The total acid number 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" 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 according to ASTM D664-01. For aluminum, copper, and carbon steel metal pieces, the total halide concentration (e.g., fluoride ion concentration) 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" is less than approximately 100 ppm, preferably less than 50 ppm, and ideally less than 10 ppm. For aluminum, copper, and iron metal pieces measured by ion chromatography, the total concentration of organic acids 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" is less than approximately 300 ppm.

[0045] Additives that can improve the lifespan of the refrigerant and A / C, as well as the durability of the compressor, are desirable. In one aspect of the present invention, the refrigerant of the present invention, comprising the composition, is used to introduce lubricating oil and other additives such as a) acid scavengers, b) performance enhancers, and c) flame suppressants into an A / C system.

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

[0047] The content incorporated by reference from paragraph

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

[0048] The activated aromatic compound may be any aromatic molecule, or a mixture thereof, that has been activated for a Friedel-Crafts addition reaction. An activated aromatic molecule for a Friedel-Crafts addition reaction is defined as any aromatic molecule capable of addition with a mineral acid. In particular, an aromatic molecule capable of addition with any mineral acid in the environment of this application (AC system) or during the thermal stability test described in ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems". Such molecules or compounds are generally activated by substituting a hydrogen atom of the aromatic ring with one of the groups NH2, NHR, NRz, ADH, AD, NHCOCH3, NHCOR, 4OCH3, OR, CH3, 4C2H5, R, or C6H5, where R is a hydrocarbon (preferably a hydrocarbon containing about 1 to about 100 carbon atoms). The activated aromatic molecule may also be an alcohol or ether in which an oxygen atom (i.e., an oxygen atom of an alcohol or ether group) is directly bonded to the aromatic group. The activated aromatic molecule may be an amine in which a nitrogen atom (i.e., the nitrogen atom of the amine group) is directly bonded to the 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), n:1 when X:O, and n:2 when X:N, Ar is an aromatic group (i.e., a C6H5 group), and R may be H or a carbon-containing group, and when 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 according to the teachings herein include diphenyl oxide (i.e., diphenyl ether), methylphenyl ether (e.g., anisole), ethylphenyl ether, butylphenyl ether, or any combination thereof. One very preferred aromatic molecule activated for Friedel-Crafts addition reactions is diphenyl oxide.

[0049] By reference to paragraph

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

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

[0051] Performance enhancer Preferred additives include those described in U.S. Patents No. 5,152,926 and No. 4,755,316, which are incorporated herein by reference. Specifically, preferred extreme pressure additives include a mixture of (A) toltriazole or a substituted derivative thereof, (B) an amine (e.g., Jeffamine M-600), and (C) (i) an ethoxylated phosphate ester (e.g., Antara LP-700 type), or (ii) a phosphoric acid alcohol (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-triadianazole (triadiaZole) derivative (e.g., Curvan 826), or a mixture thereof. Additional examples of additives that may be used are described in U.S. Patent No. 5,976,399 (Schnur, 5:12–6:51, incorporated herein by reference).

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

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

[0054] Flame suppressant Preferred flame suppressants include those described in the patent application “Compositions comprising fluoroolefins and uses thereof (WO2009018117A1),” which is similarly described by reference together with fluorinated products such as HFC-125 and / or Krytox® lubricants, as described in the patent application “Compositions comprising fluoroolefins and uses thereof (WO2009018117A1),” and also described in the patent application “Compositions comprising fluoroolefins and uses thereof (WO2009018117A1).”

[0055] Miscibility / Package Stability While HFO-1234yf is generally known to be compatible with polyalkylene glycols or 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 substantially do not contain PAG lubricants lacking the above properties. "Substantially free" means that if the compositions of the present invention contain HFO-1234yf, the composition contains less than 5% by weight, generally less than 3% by weight, and in some cases less than 0.5% by weight, of the following double-ended capped PAG ND-8 and single-ended capped PAG Dow RL244. The amount of lubricant commonly used in A / C systems is in the range of about 5 to about 10% by weight of the amount of A / C refrigerant. For example, if the A / C refrigerant charge is 600g, 60g of lubricating oil is used (90% refrigerant by weight / 10% lubricating oil by weight). However, since the refrigerant is used to transport the lubricating oil into the A / C system, the amount of PAG oil used in conjunction with the refrigerant is relatively large, approximately 50-80% lubricating oil / 20-50% refrigerant by weight (for example, about 60-65% lubricating oil by weight).

[0056] The main component of the composition of the present invention may include a lubricating oil, while the secondary component(s) may include a refrigerant having several low amounts (0-5 wt%) of additives to improve desired performance characteristics. In other words, the refrigerant is used to transport or transfer the liquid lubricating oil and additives into the A / C system.

[0057] For storage and usage conditions, lubricants and refrigerants must be miscible over a much wider range. Many cities around the world experience temperatures exceeding 37.5°C. Furthermore, lubricant / oil compositions are expected to 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 can also be anticipated that the product may be used during the winter months following a serious vehicle system failure, such as a front-end collision.

[0059] The lubricating oil / refrigerant composition is stable at temperatures of approximately -20, -30, and even -40°C, which will be helpful for storing the above composition for extended periods, such as 5 days at -20°C.

[0060] Remarkably, the compositions of the present invention maintain miscibility over a wide range of temperature and pressure conditions (for example, a composition of 20-50 wt% refrigerant / 50-80 wt% lubricant is miscible over temperatures ranging from -18°C to 37°C and pressures from 160 kPa to 945 kPa in a sealed container). The miscibility of PAG lubricant / refrigerant is performed using the ASHRAE 97:2007 "Sealed Glass Tube Method to Test the Chemical Stability of Materials for Use within Refrigerant Systems" method, by introducing predetermined amounts of lubricant and refrigerant (see table below) into a sealed tube. Subsequently, the sealed tube is placed in a water bath to determine whether the mixture is miscible over the temperature range. The test is performed 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 the temperature is gradually decreased in 5°C increments down to -50°C, held for 10 minutes at each temperature, with visual observations recorded at each temperature hold. The high-temperature segment begins at room temperature, with the temperature increasing in 5°C increments, gradually raising it to 90°C or the critical temperature of the refrigerant. Each temperature is then held for 10 minutes, and visual observations are recorded at each temperature.

[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 systems were also placed in sealed tubes containing metal (Al, Cu, carbon steel) pieces and maintained at 175°C for two weeks. The results showed that PAG lubricants / low-GWP refrigerants(s) were thermally stable at high temperatures, indicating that the compositions would not decompose during storage. No tarnishing occurred on the steel, no film or visible corrosion was present on the metal pieces, and no fluoride ions or acids were generated. No deposits or aggregates formed during the test. No color changes occurred in the refrigerant / lubricant systems.

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

[0063] While we do not wish to be bound by any theory or explanation, it is likely that the range of lubricating oil / lubricating oil miscibility will change as the refrigerant concentration increases and becomes the main component of the composition. For example, 30% by weight of lubricating oil and 70% by weight of refrigerant is the minimum for use in an A / C system, but it lacks sufficient miscibility to transport the lubricating oil into the system using the refrigerant.

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

[0065] Table 2 shows examples of low GWP refrigerant / PAG oil compositions and their miscibility ranges. The top of the table indicates the use of the product in an A / C system, and the bottom of the table indicates the manufacturing and storage temperatures (in the table, "M" means miscibility and "N" means immiscibility).

[0066] [Table 2]

[0067] One aspect of the present invention relates to a method for introducing lubricating oil into an A / C system. In the method of the present invention, a refrigerant is used to ensure that more lubricating oil or lubricating oil / additive packages are introduced into the A / C system by transporting the lubricating oil and / or lubricating oil additive packages through an A / C hose without substantially adhering to the hose (for example, when using a manual injector or manual pump, lubricating oil may adhere to the hose piping connected to the A / C system). Since the refrigerant transports the lubricating oil and delivers it into the A / C system, using a refrigerant to transfer the lubricating oil into the system ensures that more lubricating oil is introduced into the A / C system compared to manual or pump injectors. The lubricating oil or lubricating oil / additive and the refrigerant are co-packaged in a conventional container or can under conditions that the lubricating oil and refrigerant are miscible. Once out of the can, the refrigerant changes state from compressed liquefied gas to refrigerant gas. During this process, the refrigerant, which is miscible with lubricants, atomizes the lubricants or lubricants / additive mixture, and further transports the lubricants or lubricants / additive mixture along the hose into the A / C system before it can settle on the walls of the A / C refill hose.

[0068] Another aspect of the present invention relates to a method for introducing an environmentally friendly refrigerant into an A / C system. In this method of the present invention, a refrigerant / lubricant containing or not containing an additive package is introduced into the system using the same transport method as described above, and the same positive results are obtained.

[0069] The composition of the present invention (lubricating oil or lubricating oil / additive and refrigerant) can be packaged in small sealed cans of generally 8 oz or less, more generally 3 to 6 oz, and more specifically 3 to 4 oz. The composition of the present invention should be packaged in small cans having a perforated or self-sealing can top that can be connected to a vehicle's A / C system using a refrigerant refill hose, which is commonly available in the aftermarket parts market.

[0070] In one embodiment, since this product is intended for use in low GWP A / C systems including HFO-1234yf, the fittings used on the top of the can should be left-hand threaded and compatible with a male CGA166 type connector. The structure of this type of hose used to transport the product from the can to the vehicle's A / C system should conform to the SAE J2888 standard. The hose should have two different fittings. One end of the A / C refill hose should have either a puncturing needle, sometimes called a can tap, or a plunger mechanism that can connect to a small can and release the product contained in the small can. The fitting that connects to the can is a female CGA166 type fitting. The other end of the refill hose should have an SAE J639 low-side rapid-connect coupler specified for HFO-1234yf and should 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 the A / C system, the can containing the lubricant or lubricant / additive and refrigerant should first be shaken thoroughly. The vehicle engine should be started, and then the A / C system should be set to maximum cooling. Next, the above-mentioned replacement parts market refill hose should be attached 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, the contents of the can should be released using a needle or plunger mechanism. The can should be shaken slightly from side to side to help release the contents. This process should take approximately 10-15 minutes.

[0072] The instant composition can be used to add lubricating oil or lubricating oil / additive to an A / C system at temperatures of approximately 0°C to approximately 40°C, more specifically at temperatures of approximately 10°C to approximately 35°C, and even more specifically at temperatures of approximately 15°C to approximately 30°C. The composition of the present invention can be stored at temperatures from approximately -20°C to approximately 40°C to approximately 45°C, but generally it is stored at temperatures of approximately 10°C to approximately 35°C, more specifically at temperatures of approximately 15°C to approximately 30°C. Generally, when connected to an A / C system, the composition of the present invention is delivered to the A / C system at a pressure of approximately 315 kPa to approximately 435 kPa, or more specifically at a pressure of approximately 330 kPa to approximately 410 kPa, or even more specifically at a pressure of approximately 360 kPa to approximately 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 here to Figure 1, Figure 1 shows a system (100) for introducing a lubricating oil using the composition of the present invention into an automotive A / C system. The system for delivering the composition of the present invention to an automotive A / C system comprises 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 hereto to Figure 2, Figure 2 shows a kit (200) comprising a container (210) containing the composition of the present invention and having a container coupler (215), and a manual dispenser (220) for controlling the flow of the composition into an A / C system (230). The dispenser (220) further includes a dispenser coupler (240) configured to attach the container coupler (215) to facilitate the transfer of the composition of the present invention into the A / C system (230). A hose (250) is configured to connect the dispenser (220) to the A / C system (230) and to transport the composition from the dispenser (220) to the A / C system (230).

[0075] When used in the present invention, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variations thereof are intended to encompass non-exclusive inclusion. For example, a composition, process, method, article, or apparatus containing the enumerated elements is not necessarily limited to those elements alone, but may include other elements not expressly enumerated, or other elements inherent in such composition, process, method, article, or apparatus. Furthermore, unless expressly stated otherwise, “or” means comprehensive or not exclusive or. For example, condition A or B is satisfied by any one of the following: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and both A and B are true (or exist).

[0076] The transitional phrase "consisting of" excludes any unspecified elements, processes, or components. In the context of claims, with the exception of impurities normally associated with materials, such phrase excludes the inclusion of materials other than those enumerated from the claims. When the phrase "consisting of" appears in a clause of the claim rather than immediately following the preamble, it limits the elements to those specified in that clause only, and does not exclude other elements from the claims as a whole.

[0077] The transitional phrase “essentially from” is used to define a composition or method that includes materials, processes, features, components, or elements in addition to those literally disclosed, provided that these additionally included materials, processes, features, components, or elements substantially influence the basic and novel features(s) of the claimed invention, particularly the mode of action for achieving the desired results of any process of the invention. The term “essentially from” occupies an intermediate position between “includes” and “consists of.”

[0078] If applicants define an invention or a part thereof using non-restrictive terms such as "including," it should be easily understood that (unless otherwise specified) such descriptions should be interpreted to also include inventions that use the terms "essentially consisting of" or "consisting of."

[0079] Furthermore, the use of "a" or "an" is employed to describe the 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 as including one or at least one, and the singular form also includes the plural form unless it is evident that it has a different meaning.

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

Claims

1. A method for delivering polyalkylene glycol lubricant into a vehicle air conditioning system, the method comprising the step of transferring a composition comprising about 50 to about 80% by weight of polyalkylene glycol (PAG) and about 20 to about 50% by weight of a refrigerant into the vehicle air conditioning system. The aforementioned refrigerant exhibits a global warming potential (GWP) of less than 100. The composition exhibits at least one total acid value of (i) less than 3.3 mg KOH / g, (ii) less than 1.5 mg KOH / g, or (iii) less than 1.0 mg KOH / g when measured according to ASTM D664-01. A method characterized by the following:

2. The method according to claim 1, characterized in that the PAG lubricant and the refrigerant are miscible in a temperature range of -18°C to 37°C and a pressure range of 160 kPa to 945 kPa in a sealed container designed to deliver the composition into a vehicle air conditioning system.

3. The method according to claim 1, characterized in that the refrigerant has a kinematic viscosity of 40 to 50 cSt when measured at 40°C according to ASTM D445.

4. The method according to claim 1, characterized in that it includes the step of transferring the composition into a vehicle air conditioning system under pressure and temperature conditions in which the PAG lubricating oil is miscible with the refrigerant.

5. The method according to claim 1, characterized in that the refrigerant includes HFO-1234yf.

6. The method according to claim 1, further comprising the step of connecting a pressurized container containing the composition to the vehicle air conditioning system.

7. A method for delivering polyalkylene glycol lubricant into a vehicle air conditioning system, the method comprising the step of transferring a composition comprising about 50 to about 80% by weight of polyalkylene glycol (PAG) and about 20 to about 50% by weight of a refrigerant into the vehicle air conditioning system. The aforementioned refrigerant exhibits a global warming potential (GWP) of less than 100. The refrigerant has a kinematic viscosity of 40 to 50 cSt when measured at 40°C according to ASTM D445. A method characterized by the following:

8. The method according to 7, characterized in that the composition exhibits at least one total acid value of (i) less than 3.3 mg KOH / g, (ii) less than 1.5 mg KOH / g, or (iii) less than 1.0 mg KOH / g when measured according to ASTM D664-01.

9. The method according to 7, characterized in that the refrigerant includes HFO-1234yf.

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