Lubricants for use with chlorine-containing refrigerants in compressor applications - Patent Application 20070122997

Abstract

A composition comprising a compressor lubricant containing a chlorine-containing refrigerant blend, an oil of lubricating viscosity containing at least one oxygenate, and at least one phosphorus additive. The phosphorus additive may be present at 0.1 to 4 wt. %, based on the total weight of the compressor lubricant. The disclosed technology provides compressor lubricant compositions suitable for use with chlorine-containing refrigerant blends. These compositions are believed to reduce interactions between the refrigerant and compressor bearing surfaces, thereby reducing refrigerant degradation that can lead to bearing corrosion or wear.

Description

[Technical Field]

[0001] The disclosed technology relates to lubricants for use in centrifugal compressor systems, where the refrigerant includes a chlorine-containing refrigerant. [Background technology]

[0002] Previously, lubricants developed for use with hydrofluoroolefins contained no additives other than antioxidants. However, in centrifugal compressor applications, conventional lubricants have proven inadequate to protect against journal bearing wear and corrosion on bearing surfaces (Babbitt layers), especially those made of metal alloys.

[0003] Metal corrosion is believed to be the result of the interaction of Babbitt alloy with the refrigerant under anaerobic conditions. In air, the metal in Babbitt oxidizes with the air, providing a passive surface that prevents corrosion. In anaerobic systems, such as those found in centrifugal compressors, the passivating oxide layer does not regenerate after the Babbitt surface is subjected to wear. This can be exacerbated when chlorine-containing HFO refrigerants are used, as the metal in the Babbitt material can react with the chlorine in the refrigerant to form metal chloride salts that are soluble in the lubricant.

[0004] Therefore, there is a need for lubricants that prevent wear and corrosion in compressor systems that use chlorine-containing refrigerants, including centrifugal compressor systems. Summary of the Invention [Means for solving the problem]

[0005] The disclosed technology provides compressor lubricant compositions suitable for use with chlorine-containing refrigerant blends. These compositions are believed to reduce interactions between the refrigerant and compressor bearing surfaces, thereby reducing refrigerant degradation that can lead to bearing corrosion or wear. Thus, the compositions include a chlorine-containing refrigerant blend, an oil of lubricating viscosity having at least one oxygenate, and a compressor lubricant containing at least one phosphorus additive.

[0006] The at least one phosphorus additive may be present at 0.1 to 4 wt. % (or 0.1 to 3 wt. %, or 0.2 to 1 wt. %, or 0.3 to 0.6 wt. %) based on the total weight of the compressor lubricant. The at least one phosphorus additive may comprise a phosphate, a phosphite, a phosphonate, or a mixture thereof. In some embodiments, the at least one phosphorus additive is an aryl phosphate, or an alkenyl phosphite, such as C 16 ~C 18 It may include an aryl phosphate in combination with an alkenyl phosphite. Suitable phosphorus additives include, but are not limited to, butylated triphenyl phosphate, tricresyl phosphate, dimethyl octadecyl phosphonate, or mixtures thereof.

[0007] In some embodiments, the compressor lubricant may further include at least one acid scavenger (e.g., glycidyl epoxide) and / or at least one antioxidant (e.g., ditert-butylcresol) and / or at least one metal passivator (e.g., benzotriazole).

[0008] The compositions disclosed herein include a chlorine-containing refrigerant blend, which may be a chlorine-containing compound and a hydrofluoroolefin ("HFO"). An exemplary chlorine-containing refrigerant blend includes R-514A (74.7% HFO-1336mzz-Z, 25.3% trans-1,2-dichloroethylene (t-DCE)).

[0009] The oxygenates suitable for use as oils of lubricating viscosity are not overly limited. The oxygenate may comprise at least one alcohol, ester oil, ether oil, or a combination thereof. In some embodiments, the oxygenate may comprise at least one polyol ester, at least one polyalkylene glycol, at least one polyvinyl ether, or a combination thereof. In yet other embodiments, the oxygenate may comprise at least one polyol ester, such as a polyol ester derived from a reaction mixture of dipentaerythritol, heptanoic acid, isononanoic acid, caprylic acid, or capric acid.

[0010] In some embodiments, the oil of lubricating viscosity may further comprise at least one hydrocarbon oil. The at least one hydrocarbon oil may be present in an amount of 0.1 to 25 wt % (or 5 to 25 wt %), based on the total weight of the oil of lubricating viscosity. In some embodiments, the hydrocarbon oil may be an aromatic hydrocarbon, such as an alkyl benzene.

[0011] In some embodiments, the compressor lubricant may further comprise an acid scavenger that is a hydrocarbyl-substituted glycidol ether. In the same or other embodiments, the compressor lubricant may have a viscosity grade of 46 to 170 at 40°C, as measured using ASTM D445.

[0012] In some embodiments, a refrigeration compressor is disclosed that is filled with a chlorine-containing refrigerant blend and a compressor lubricant. The compressor lubricant may include an oil of lubricating viscosity having at least one oxygenate; and at least one phosphorus-containing additive. In some embodiments, the compressor may be a centrifugal compressor.

[0013] In some embodiments, a method for reducing metal corrosion in a compressor system is disclosed. The method may include adding at least one phosphorus-containing additive to a compressor lubricant. The compressor lubricant may include an oil of lubricating viscosity having at least one oxygenate. In some embodiments, the compressor system may contain a chlorine-containing refrigerant. In some embodiments, the reduction in metal corrosion may be measured using ASHRAE 97 and compared to a lubricant that does not contain the at least one phosphorus-containing additive disclosed herein.

[0014] In some embodiments, additional benefits of the disclosed compressor lubricants containing phosphorus-containing additives may be realized. For example, compressor wear may also be reduced. In other embodiments, reduced wear may be measured using ASTM D4172 and / or ASTM D2783. In still other embodiments, corrosion of metals or alloys within the compressor may also be reduced. Exemplary metals include, but are not limited to, at least one of tin, steel, copper, or aluminum. The disclosed compressor lubricants containing phosphorus-containing additives may also perform well in compressor applications where the compressor operates under anaerobic conditions. In some embodiments, the compressor may be a centrifugal compressor. DETAILED DESCRIPTION OF THE INVENTION

[0015] Further features and embodiments of the compositions are described below by way of non-limiting example. The compositions can include a compressor lubricant containing a chlorine-containing refrigerant blend, an oil of lubricating viscosity having at least one oxygenate, and at least one phosphorus additive. These compositions reduce wear and / or metal corrosion in the babbitt of compressor journal bearings.

[0016] Oxygenate The refrigeration lubricant includes an oil of lubricating viscosity that is an oxygenate. As used herein, oxygenate refers to organic compounds that contain oxygen as one of their components. These include organic compounds with at least one aprotic or protic oxygen for every six carbon atoms. Oxygenates also include organic compounds with at least one aprotic or protic oxygen for every seven carbon atoms, or one aprotic or protic oxygen for every eight carbon atoms, or at least one aprotic or protic oxygen for every 12 carbon atoms. Oxygenates also include organic compounds with at least one aprotic or protic oxygen for every 16 carbon atoms, or one aprotic or protic oxygen for every 20 carbon atoms.

[0017] Oxygenates can include, for example, alcohols, ester oils, and ether oils. The oxygenate can be present in the refrigeration lubricant as at least 45% by weight of an oil of lubricating viscosity, based on the total weight of the refrigeration lubricant. In some examples, the oxygenate can be present at at least 50% by weight to at least 80% by weight. In other embodiments, the oxygenate can be present at at least 80% by weight to at least 90% by weight, or at least 95% by weight. In still other embodiments, the oxygenate can be present at at least 96%, 97%, 98%, or at least 99% by weight, based on the total weight of the lubricant composition.

[0018] Alcohols suitable for use as oils of lubricating viscosity include monohydric alcohols such as ethanol, methanol, propylene alcohol derivatives such as n-butanol and tert-butanol, and isopropyl alcohol, and higher branched alcohols include pentanol, hexanol, heptanol, octanol, decanol, dodecanol, tetradecanol, hexadecanol, and isomers of combinations thereof. Examples of branched alcohols include 2-ethylhexanol, isooctanol, isodecanol, and isododecanol. As used herein, alcohol also includes polyols such as propylene glycol, ethylene glycol, 1,4-butanediol, pentaerythritol, and trimethylolpropane.

[0019] Ethers suitable for use as oils of lubricating viscosity include those produced from petrochemical and renewable feedstocks. Examples include methyl tertiary butyl ether (MTBE), tertiary amyl methyl ether (TAME), ethyl tertiary butyl ether (ETBE), and tertiary amyl ethyl ether (TAEE). Other examples of ethers include tert-hexyl methyl ether (THEME) and diisopropyl ether. Polyethers are also considered under the term "ether" herein and include, for example, diethylene glycol dibutyl ether. Low molecular weight oligomers of polyalkylene glycols (i.e., polyalkylene oxides), including polyethylene glycol (PEG), polypropylene glycol (PPG), and mixed polymers thereof, may also be suitable.

[0020] Ester oils suitable for use as oils of lubricating viscosity include esters of monocarboxylic acids and monohydric alcohols, diesters of diols and monocarboxylic acids and diesters of dicarboxylic acids and monohydric alcohols, polyol esters of monocarboxylic acids, and polyesters of monohydric alcohols and polycarboxylic acids, and mixtures thereof. Esters can be broadly divided into two categories: synthetic and natural.

[0021] Synthetic esters suitable for use as oils of lubricating viscosity may include esters of monocarboxylic acids (such as acetic acid, propionic acid, neopentanoic acid, 2-ethylhexanoic acid) and dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid dimer, malonic acid, alkyl malonic acids, and alkenyl malonic acids) with any of a variety of monohydric alcohols (e.g., butyl alcohol, pentyl alcohol, neopentyl alcohol, hexyl alcohol, octyl alcohol, iso-octyl alcohol, nonyl alcohol, decyl alcohol, isodecyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, and propylene glycol). Specific examples of these esters include dibutyl adipate, di(2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, didecyl phthalate, diecocyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two moles of 2-ethylhexanoic acid. Other synthetic esters include C5-C 12Included are those made from monocarboxylic acids and polyols and polyol ethers, such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tripentaerythritol. The esters can also be monoesters of monocarboxylic acids and monohydric alcohols.

[0022] Suitable esters also include esters of hydroxy-substituted carboxylic acids, such as tartaric acid, malic acid, glycolic acid, and hydroxy fatty acids (eg, 12-hydroxystearic acid), in combination with monohydric alcohols, such as those mentioned above.

[0023] Natural (or bio-derived) esters refer to materials derived from renewable biological resources, organisms, or entities, and are distinct from materials derived from petroleum or equivalent sources. Suitable natural esters in heat transfer fluids include fatty acid triglycerides, hydrolyzed or partially hydrolyzed triglycerides, or transesterified triglyceride esters, such as fatty acid methyl esters (FAMEs). Suitable triglycerides include, but are not limited to, palm oil, soybean oil, sunflower oil, rapeseed oil, olive oil, linseed oil, and related materials. Other triglyceride sources include, but are not limited to, algae, tallow, and zooplankton.

[0024] In some embodiments, the oil of lubricating viscosity is an oxygenate comprising at least one polyol ester ("polyolester, POE") oil, the polyol ester oil comprising a polyol esterified with at least one (mono)carboxylic acid having at least 5 carbon atoms. In yet other embodiments, the polyol ester oil comprises a polyol esterified with a mixture of (mono)carboxylic acids or their anhydrides, the (mono)carboxylic acids or anhydrides individually having 5 to 13 carbon atoms. The C5 carboxylic acids or anhydrides are preferably C6 carboxylic acids or C7 carboxylic acids or anhydrides. 13Suitable ratios of carboxylic acids or anhydrides include, but are not limited to, 95:5 to 5:95. In yet another embodiment, the mixture of (mono)carboxylic acids or their anhydrides comprises at least three C5-C 13 Suitable polyols include carboxylic acids or anhydrides. Suitable polyols include, but are not limited to, trimethylolpropane, dipentaerythritol, neopentyl glycol, monopentaerythritol, polypentaerythritol, or combinations thereof. In some embodiments, the POE may include esters and / or complex esters of aromatic polycarboxylic acids or their anhydrides. The complex esters may be composed of oligomeric units composed of polyols (which may include, but are not limited to, trimethylolpropane, dipentaerythritol, neopentyl glycol, monopentaerythritol, polypentaerythritol) and polyacids or acid anhydrides (which may include, but are not limited to, succinic acid, glutaric acid, adipic acid, citric acid, trimellitic acid, pyromellitic acid), or any mixture thereof. The complex esters may be fully or partially capped with functional (mono)carboxylic acids or (mono)alkyl alcohols, or singly capped glycol ethers, or any mixture thereof.

[0025] As used herein, "(mono)carboxylic acid" or "(mono)alkyl alcohol" means that the (mono) is optional, i.e., the carboxylic acid or alkyl alcohol compound can be mono or poly. However, in some embodiments of the disclosed technology, only monocarboxylic acids and / or monoalkyl alcohols are present.

[0026] In some embodiments, the oxygenate may include an aromatic ester. Suitable aromatic esters are not overly limited. The aromatic hydrocarbon used to prepare the aromatic ester may have 1 to 5, 1 to 4, or 2 to 4 carboxylic acid functional groups. In some embodiments, the aromatic hydrocarbon may be an aromatic carboxylic acid, an aromatic polycarboxylic acid anhydride, an aromatic polycarboxylic acid ester, or a mixture thereof. While not limiting the disclosed technology to a single theory of operation, it is believed that when a carboxyl group is directly bonded to an aromatic ester, the degree of freedom of rotation around that bond is limited. This results in a more rigid molecule with a higher neat viscosity compared to the molecular weight of the aromatic ester. In some embodiments, the aromatic ester can be prepared using a polycyclic aromatic acid or anhydride, such as 1,8-naphthalic acid.

[0027] The (mono)alkyl alcohol used to prepare the aromatic ester is at least one C4-C 15 or C8~C 13 It may comprise a straight chain or branched chain alcohol. In some embodiments, the (mono)alkyl alcohol is 10 Alcohol and C 13 May contain alcohol. 10 C for alcohol 13 In yet another embodiment, the (mono)alkyl alcohol is a branched C 10 and branched chain C 13 The alcohol may comprise a (mono)alkyl alcohol, i.e., the (mono)alkyl alcohol may comprise a C 10 Alkyl alcohol and C 13 It is a mixture with alkyl alcohols, both of which are branched chain.

[0028] The glycol ethers used to make the aromatic esters may include alkylene glycols, which have the general structure R1(-O-R2) x-OR3, where R1 and R3 may individually be hydrogen or a C1-C4 hydrocarbyl group, and R2 may be a monoether or a single, alternating, or randomly distributed polyether subunit. Alternatively, the aromatic ester may be a complex ester in which a non-doubly capped PAG group links two aromatic acids together. In some embodiments, the oxygenate may include at least one aromatic ester that is a benzoate, phthalate, trimellitate, pyromellitate, or a mixture thereof.

[0029] In some embodiments, the oxygenate may comprise at least one polyol ester, at least one polyalkylene glycol, at least one polyvinyl ether, or a combination thereof. In yet other embodiments, the oxygenate may comprise at least one polyol ester, such as a polyol ester derived from a reaction mixture of dipentaerythritol, heptanoic acid, isononanoic acid, caprylic acid, or capric acid.

[0030] In some embodiments, the oil of lubricating viscosity may further comprise at least one hydrocarbon oil. The at least one hydrocarbon oil may be present in an amount of 0.1 to 25 wt % (or 5 to 25 wt %) based on the total weight of the oil of lubricating viscosity. In some embodiments, the hydrocarbon oil may be an aromatic hydrocarbon, such as an alkylbenzene. Suitable alkylbenzenes are not overly limited and include both linear and branched alkylbenzenes.

[0031] Branched alkylbenzenes can be produced using a polymer of propylene and benzene as a raw material and a catalyst such as hydrogen fluoride. Linear alkylbenzenes can be prepared from n-paraffins and benzene using the same hydrogen fluoride catalyst. The number of carbon atoms in the alkyl group is preferably 1 to 30, or 4 to 20, depending on the desired viscosity of the lubricating base oil. In some embodiments, the number of alkyl groups in one molecule of alkylbenzene can be 1 to 4, or 1 to 3.

[0032] The kinematic viscosity of alkylbenzene at 40°C is 1 to 50 mm 2 / s or 1 to 25 mm 2 In some embodiments, the alkylbenzene may have a viscosity of about 4 mm / s at 40° C. 2 / s (cSt).

[0033] Phosphorus Additive The refrigeration lubricant may have at least one phosphorus additive. Suitable phosphorus additives may be selected from phosphites, phosphonates, alkyl phosphate esters, amines or ammonium phosphate salts.

[0034] Phosphorus esters include reaction products of dihydrocarbyl phosphites and trihydrocarbyl phosphites, such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite, dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite, and polypropylene-substituted phenol phosphites; metal thiocarbamates such as zinc dioctyldithiocarbamate, barium heptylphenol diate, and the like; amine salts or derivatives of alkyl and dialkylphosphoric acids, such as the amine salt of the reaction product of a dialkyldithiophosphoric acid with propylene oxide, followed by further reaction with P2O5, and mixtures thereof (as described in U.S. Pat. No. 3,197,405).

[0035] The amine phosphate can be an amine salt of (i) a monohydrocarbyl phosphate, (ii) a dihydrocarbyl phosphate, (iii) a hydroxy-substituted diester of phosphoric acid, or (iv) a phosphorylated hydroxy-substituted di- or triester of phosphoric acid. The amine salt of the sulfur-free, phosphorus-containing compound can be a salt of a primary amine, a secondary amine, a tertiary amine, or a mixture thereof.

[0036] The amine phosphate can be derived from a mono- or dihydrocarbyl phosphate (typically an alkyl phosphate), or a mixture thereof. The alkyl of the mono- or dihydrocarbyl phosphate can include a linear or branched alkyl group of 3 to 36 carbon atoms. The hydrocarbyl group of the linear or branched hydrocarbyl phosphate can contain 4 to 30 or 8 to 20 carbon atoms. Examples of suitable hydrocarbyl groups of the hydrocarbyl phosphate can include isopropyl, n-butyl, sec-butyl, amyl, 4-methyl-2-pentyl (i.e., methylamyl), n-hexyl, n-heptyl, n-octyl, iso-octyl, 2-ethylhexyl, nonyl, 2-propylheptyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, oleyl, or a combination thereof. In one embodiment, the phosphate is a mixture of mono-(2-ethyl)hexyl phosphate and di-(2-ethyl)hexyl phosphate.

[0037] Examples of suitable primary amines include ethylamine, propylamine, butylamine, 2-ethylhexylamine, octylamine, and dodecylamine, as well as fatty amines such as n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine, and oleamine. Other useful fatty amines include commercially available fatty amines such as "Armeen®" amines (products available from Akzo Chemicals, Chicago, Ill.), such as Armeen C, Armeen O, Armeen OL, Armeen T, Armeen HT, Armeen S, and Armeen SD, where the letter designation refers to the aliphatic group, such as coco, oleyl, tallow, or stearyl groups.

[0038] In some embodiments, the at least one phosphorus additive may comprise a phosphate, a phosphite, a phosphonate, or a mixture thereof. In some embodiments, the at least one phosphorus additive may comprise an aryl phosphate, or an aryl phosphate in combination with an alkenyl phosphite. Suitable phosphorus additives include, but are not limited to, C 16 ~C 18 alkenyl phosphite, butylated triphenyl phosphate, tricresyl phosphate, dimethyl octadecyl phosphonate, or mixtures thereof. In some embodiments, the refrigeration lubricant is C 16 ~C 18 The at least one phosphorus additive may be present in an amount of 0.1 to 4 wt. % (or 0.1 to 3 wt. %, or 0.2 to 1 wt. %, or 0.3 to 0.6 wt. %) based on the total weight of the compressor lubricant.

[0039] In some embodiments, the compressor lubricant may further include at least one acid scavenger (e.g., glycidyl epoxide) and / or at least one antioxidant (e.g., ditert-butylcresol) and / or at least one metal passivator (e.g., benzotriazole).

[0040] The compositions disclosed herein include a chlorine-containing refrigerant blend, which may be a chlorine-containing compound and a hydrofluoroolefin ("HFO"). An exemplary chlorine-containing refrigerant blend includes R-514A (74.7% HFO-1336mzz-Z, 25.3% trans-1,2-dichloroethylene (t-DCE)).

[0041] In some embodiments, the compressor lubricant may further comprise an acid scavenger that is a hydrocarbyl-substituted glycidol ether. In the same or other embodiments, the compressor lubricant may have a viscosity grade of 46 to 170 at 40°C, as measured using ASTM D445.

[0042] In some embodiments, a refrigeration compressor is disclosed that is charged with a chlorine-containing refrigerant blend and a compressor lubricant. The compressor lubricant may include an oil of lubricating viscosity that is a mixture of at least one oxygenate and at least one alkylbenzene; and at least one phosphorus-containing additive. In some embodiments, the compressor may be a centrifugal compressor.

[0043] In some embodiments, a method for reducing tin corrosion in a compressor system is disclosed. The method may include adding at least one phosphorus-containing additive to a compressor lubricant. The compressor lubricant may include an oil of lubricating viscosity that is a mixture of at least one oxygenate and at least one alkylbenzene. In some embodiments, the compressor system may contain a chlorine-containing refrigerant. In some embodiments, the reduction in tin corrosion may be measured using ASHRAE 97 and compared to a lubricant that does not contain the at least one phosphorus-containing additive disclosed herein.

[0044] In some embodiments, additional benefits of the disclosed compressor lubricants containing phosphorus-containing additives may be realized. For example, compressor wear may also be reduced. In other embodiments, reduced wear may be measured using ASTM D4172 and / or ASTM D2783. In still other embodiments, corrosion of other types of metals or alloys within the compressor may also be reduced. Exemplary metals include, but are not limited to, at least one of steel, copper, or aluminum. The disclosed compressor lubricants containing phosphorus-containing additives may also perform well in compressor applications where the compressor operates under anaerobic conditions. In some embodiments, the compressor may be a centrifugal compressor.

[0045] The amount of each chemical component listed is exclusive of any solvent or diluent oil that may be customarily present in commercially available materials, i.e., expressed on an active chemical basis, unless otherwise indicated. However, unless otherwise indicated, each chemical or composition referred to herein should be understood to be a commercial grade material that may contain isomers, by-products, derivatives, and other such materials commonly understood to be present in commercial grades.

[0046] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group" is used in its ordinary sense, which is well known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having hydrocarbon character. Examples of hydrocarbyl groups include: Hydrocarbon substituents, i.e., aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic, aliphatic, and alicyclic-substituted aromatic substituents, as well as cyclic substituents in which the ring is completed through another portion of the molecule (e.g., two substituents together form a ring); Substituted hydrocarbon substituents, i.e., substituents containing non-hydrocarbon groups which do not alter the hydrocarbon character of the substituent in the context of this invention (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy); Hetero substituents, i.e., substituents that have hydrocarbon character but contain atoms other than carbon in the ring or chain composed of carbon atoms, include substituents such as pyridyl, furyl, thienyl, and imidazolyl. Heteroatoms include sulfur, oxygen, and nitrogen. Generally, no more than two or no more than one non-hydrocarbon substituent will be present for every 10 carbon atoms in the hydrocarbyl group. Alternatively, there may be no non-hydrocarbon substituents in the hydrocarbyl group.

[0047] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may differ from those originally added. For example, metal ions (e.g., from detergents) may migrate to other acidic or anionic sites on other molecules. The products formed thereby, including the products formed upon using the compositions of the present invention in their intended applications, may not be easily described. Nevertheless, all such modifications and reaction products are included within the scope of the present invention. The present invention encompasses compositions prepared by mixing the components described above.

[0048] The invention herein is useful as a lubricant for refrigeration compressors, which can be better understood with reference to the following examples. [Example]

[0049] Multiple lubricant samples are prepared and evaluated for various lubricant properties, including viscosity, wear, and lubricant stability and compatibility with various metals. Lubricant viscosity is measured at 40°C and 100°C using ASTM D445. The lubricant compositions (active chemical basis) and their viscosity and wear properties are summarized in Table 1 below.

[0050] [Table 1] 1 - Baseline lubricant viscosity grade 2-Butylated Triphenyl Phosphate 3-C 16 ~C 18 Alkenyl Phosphite 4-Acid Scavenger 5-Antioxidants 6-Metal Passivator

[0051] As can be seen in Table 1, the lubricants containing the phosphorus additive have improved Falex wear and wear properties as measured using ASTM D2783.

[0052] Stability and Compatibility of Lubricants and R-514A at 125°C and 175°C Five different lubricants were combined with R-514A refrigerant. R-514A is a non-azeotropic blend of 25.3 wt.% trans-1,2-dichloroethylene (R-1130(E)) and 74.7 wt.% olefin (R1336mzzZ). For each lubricant, two sets of tubes were prepared, each set containing four tubes. The first three tubes contained a 2:8 ratio of refrigerant and lubricant (0.4 g refrigerant to 1.6 g lubricant). One metal catalyst (copper, aluminum, or steel) was also placed in each tube. The fourth tube contained a larger mixture of lubricant and refrigerant in the same 2:8 ratio (0.5 g refrigerant and 2.0 g lubricant) and metal catalyst.

[0053] A visual evaluation of both the liquid and metal catalyst is performed and recorded. The first set of tubes is then aged at a constant temperature of 125°C for 7 days. The second set of tubes is aged at a constant temperature of 175°C for 7 days. After 7 days, the first three tubes of both sets are visually inspected for changes in lubricant color, opacity, particulate loading, corrosion of the metal catalyst, and copper plating on the surface of the steel catalyst. Visual results are obtained and recorded.

[0054] The color of lubricants is measured according to ASTM D1500. For this color test, a liquid sample is placed in a test container and compared to a colored glass disc using a colorimeter and a standard light source. The glass disc readings range from 0.5 to 8.0.

[0055] The visual results compared to unaged tubes are set forth in Table 2 below.

[0056] [Table 2] 1 - Color is compared to the unaged sample and the value is expressed as aged / unaged.

[0057] As can be seen from the visual test results above, the lubricant without phosphorus additive with the metal coupon aged at 175°C for 14 days underwent a color change, indicating that the lubricant had reacted with the metal coupon, which is undesirable in a compressor system.

[0058] Accordingly, a method for reducing corrosion in a compressor system charged with a chlorine-containing refrigerant is disclosed. The method may include adding at least one phosphorus-containing additive to a compressor lubricant, wherein the compressor lubricant includes an oil of lubricating viscosity having at least one oxygenate. The metal may be at least one of copper, steel, or aluminum.

[0059] The amount of reduced corrosion may be measured using ASHRAE 97. Compressor wear may also be reduced as measured using ASTM D4172 and / or ASTM D2783. In some embodiments, the compressor may operate under anaerobic conditions. In the same or alternative embodiments, the compressor may be a centrifugal compressor.

[0060] Each of the documents mentioned above is incorporated herein by reference, including any prior application to which priority is claimed, whether or not specifically listed above. The citation of any document is not an admission that such document qualifies as prior art or constitutes general knowledge of one of ordinary skill in the art in any jurisdiction. Except in the examples or where otherwise expressly indicated, all quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, etc., are to be understood as modified by the word "about." It should be understood that the upper and lower limits of quantities, ranges, and ratios set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention may be used together with ranges or amounts for any of the other elements.

[0061] As used herein, the transitional term "comprising," which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. However, in each occurrence of "comprising" herein, the term is also intended to encompass, as alternative embodiments, the phrases "consisting essentially of" and "consisting of," where "consisting" excludes any unspecified element or step, and "consisting essentially of" permits the inclusion of additional, unrecited elements or steps that do not materially affect the basic and novel characteristics of the composition or method under consideration.

[0062] While certain representative embodiments and details have been shown for the purpose of illustrating the present invention, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention, which in this regard should be limited only by the claims that follow.

Claims

1. a chlorine-containing refrigerant blend; and a. A compressor lubricant comprising: i. an oil of lubricating viscosity comprising at least one oxygenate; ii. A compressor lubricant comprising at least one phosphorus additive.

2. 10. The composition of claim 1, wherein the at least one phosphorus additive is present at 0.1 to 4 wt % (or 0.1 to 3 wt %, or 0.2 to 1 wt %, or 0.3 to 0.6 wt %) based on the total weight of the compressor lubricant.

3. 3. The composition of claim 1 or 2, wherein the at least one phosphorus additive comprises a phosphate, a phosphite, a phosphonate, or a mixture thereof.

4. The at least one phosphorus additive is an aryl phosphate or an alkenyl phosphite, such as C １６ ~C １８ The composition of any one of claims 1 to 3, comprising an aryl phosphate in combination with an alkenyl phosphite.

5. The composition of any one of claims 1 to 4, wherein the at least one phosphorus comprises butylated triphenyl phosphate, tricresyl phosphate, dimethyl octadecyl phosphonate, or a mixture thereof.

6. 6. The composition of any one of claims 1 to 5, wherein the compressor lubricant further comprises at least one acid scavenger and / or at least one antioxidant (e.g., ditert-butylcresol) and / or at least one metal passivator (e.g., benzotriazole).

7. The composition of claim 6, wherein the acid scavenger is a hydrocarbyl-substituted glycidol ether (e.g., glycidyl epoxide).

8. 8. The composition of any one of claims 1 to 7, wherein the chlorine-containing refrigerant blend comprises a chlorine-containing compound and a hydrofluoroolefin ("HFO").

9. 9. The composition of claim 8, wherein the chlorine-containing refrigerant blend comprises R-514A.

10. The composition of any one of claims 1 to 9, wherein the oxygenate comprises at least one alcohol, an ester oil, an ether oil, or a combination thereof.

11. 11. The composition of claim 10, wherein the oxygenate comprises at least one polyol ester, at least one polyalkylene glycol, at least one polyvinyl ether, or a combination thereof.

12. 12. The composition of claim 11, wherein the oxygenate comprises at least one polyol ester, such as a polyol ester derived from a reaction mixture of dipentaerythritol, heptanoic acid, isononanoic acid, caprylic acid, or capric acid.

13. The composition of any one of claims 1 to 12, wherein the oil of lubricating viscosity further comprises at least one hydrocarbon oil.

14. 14. The composition of claim 13, wherein the at least one hydrocarbon oil is present at 0.1 to 25 wt % (or 5 to 25 wt %), based on the total weight of the oil of lubricating viscosity.

15. 15. The composition of claim 13 or 14, wherein the hydrocarbon oil is an aromatic hydrocarbon.

16. 16. The composition of claim 15, wherein the aromatic hydrocarbon is an alkylbenzene.

17. 17. The composition of any one of claims 1 to 16, wherein the compressor lubricant has a viscosity grade of 46 to 170 at 40°C as measured using ASTM D445.

18. A refrigeration compressor filled with a chlorine-containing refrigerant blend and a compressor lubricant according to any one of claims 1 to 17.

19. 20. The refrigeration compressor of claim 18, wherein the compressor is a centrifugal compressor.

20. 1. A method for reducing tin corrosion in a compressor system, the method comprising: a. adding at least one phosphorus-containing additive to the compressor lubricant; The compressor lubricant is b. an oil of lubricating viscosity comprising at least one oxygenate; and The method, wherein the compressor system contains a chlorine-containing refrigerant.

21. 21. The method of claim 20, wherein the tin corrosion is reduced as measured using ASHRAE 97.

22. 98. The method of claim 21, wherein the tin corrosion is reduced compared to a lubricant that does not contain the at least one phosphorus-containing additive.

23. A method according to any one of claims 20 to 23, wherein wear on the compressor is also reduced.

24. 24. The method of claim 23, wherein the wear is reduced as measured using ASTM D4172 and / or ASTM D2783.

25. 25. The method of any one of claims 20 to 24, wherein corrosion of at least one of steel, copper, or aluminum is also reduced.

26. The method of any one of claims 20 to 25, wherein the compressor operates under anaerobic conditions.

27. 27. The method of any one of claims 20 to 26, wherein the compressor is a centrifugal compressor.

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