LUBRICANT FOR USE WITH CHLORINE-CONTAINING REFRIGERANTS IN COMPRESSOR APPLICATIONS

- The Lubrizol Corporation

A composition comprising a chlorine-containing refrigerant blend and a compressor lubricant comprising: an oil of lubricating viscosity comprising at least one oxygenate; and at least one phosphorous additive. The phosphorous additive may be present at 0.1 to 4 5 wt %, based on a total weight of the compressor lubricant.

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Description
FIELD OF THE INVENTION

The disclosed technology relates to lubricants for use in centrifugal compressor systems, wherein the refrigerant comprises chlorine-containing refrigerant.

BACKGROUND OF THE INVENTION

Traditionally, lubricants developed for use with hydrofluoro olefins do not contain additives beyond antioxidants. In centrifugal compressor applications, however, traditional lubricants have proved to provide insufficient protection to prevent journal bearing wear and corrosion in the bearing surface (Babbitt layer), particularly in surfaces made with metal alloys.

It is believed metal corrosion is a result of the interaction of the Babbitt alloy with the refrigerant under anaerobic conditions. In air, the metal in the Babbitt oxidizes with the air to provide passive surfaces that prevent corrosion. In an anaerobic system, such as that found in centrifugal compressors, the passivating oxide layer will not be regenerated after the Babbitt surface has experienced wear. This may be further exacerbated when chlorine-containing HFO refrigerants are used, as the metal in the Babbitt material may react with the chlorine in the refrigerant and form metal-chloride salts that are soluble in the lubricant.

Thus, there is a need for lubricants that prevent wear and corrosion in compressor systems with chlorine-containing refrigerants, including centrifugal compressor systems.

SUMMARY OF THE INVENTION

The disclosed technology provides compressor lubricant compositions suitable for use with a chlorine-containing refrigerant blend. It is believed these compositions reduce the interaction between the refrigerant and compressor bearing surface, thereby reducing degradation of the refrigerant resulting bearing corrosion or wear. Accordingly, the compositions comprise a chlorine-containing refrigerant blend and a compressor lubricant comprising an oil of lubricating viscosity having at least one oxygenate; and at least one phosphorous additive.

The at least one phosphorous 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 a total weight of the compressor lubricant. The at least one phosphorous additive may comprise a phosphate, phosphite, phosphonate, or mixtures thereof. In some embodiments, the at least one phosphorous additive may comprise an aryl phosphate or an aryl phosphate in combination with an alkenyl phosphite, for example a C16-C18 alkenyl phosphite. Suitable phosphorous additives include, but are not limited to, butylated triphenyl phosphate, tricresyl phosphate, dimethyl octadecyl phosphonate, or mixtures thereof.

In some embodiments, the compressor lubricant may further comprise at least one acid scavenger (for example, glycidyl epoxide) and/or at least one antioxidant (for example, ditertbutyl cresol) and/or at least one metal passivator (for example, benzotriazole).

The composition disclosed herein comprises a chlorine-containing refrigerant blend, which may be a chlorine containing compound and a hydrofluoro olefin (“HFO”). Exemplary chlorine-containing refrigerant blends include R-514A (74.7% HFO-1336mzz-Z, 25.3% trans-1,2-dichloroethylene (t-DCE)).

Oxygenates suitable for use as an oil of lubricating viscosity are not overly limited. The oxygenate may comprise at least one alcohol, ester oil, ether oil, or combinations thereof. In some embodiments, the oxygenate may comprise at least one polyol ester, at least one polyalkylene glycol, at least one polyvinyl ether, or combinations thereof. In yet other embodiments, the oxygenate may comprise at least one polyol ester, for example a polyol ester derived from the reaction mixture of di-pentaerythritol, heptanoic acid, iso-nonanoic acid, caprylic acid, or capric acid.

In some embodiments, the oil of lubricating viscosity may further comprise as at least one hydrocarbon oil. The at least one hydrocarbon oil may be present at 0.1 to 25 wt % (or 5 to 25 wt %), based on a total weight of the oil of lubricating viscosity. In some embodiments, the hydrocarbon oil may be an aromatic hydrocarbon, for example, alkylbenzene.

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.

In some embodiments, a refrigeration compressor charged with a chlorine-containing refrigerant blend and a compressor lubricant is disclosed. The compressor lubricant may comprise 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.

In some embodiments, a method of reducing metal corrosion in a compressor system is disclosed. The method may comprise adding at least one phosphorus containing additive to a compressor lubricant. The compressor lubricant may comprise 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 without the at least one phosphorus containing additive disclosed herein.

In some embodiments, additional benefits of the disclosed compressor lubricant comprising a phosphorous containing additive may be realized. For example, wear in the compressor may also be reduced. In other embodiments, the reduction in wear may be measured using ASTM D4172 and/or ASTM D2783. In yet other embodiments, corrosion of metals or alloys in 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 lubricant comprising a phosphorous containing additive may also work well in compressor applications wherein the compressor operates under anaerobic conditions. In some embodiments, the compressor may be a centrifugal compressor.

DETAILED DESCRIPTION OF THE INVENTION

Additional features and embodiments of compositions will be described below by way of non-limiting illustration. The compositions may comprise a chlorine-containing refrigerant blend and a compressor lubricant comprising an oil of lubricating viscosity having at least one oxygenate; and at least one phosphorous additive. These compositions result in less wear and/or metal corrosion in the Babbitt of the compressor journal bearings.

Oxygenate

The refrigeration lubricant comprises an oil of lubricating viscosity that is an oxygenate. As used herein, oxygenate refers to organic compounds containing oxygen as one of their components. These include organic compounds having at least 1 aprotic or protic oxygen for every 6 carbon atoms. Oxygenates also include organic compounds having at least 1 aprotic or protic oxygen for every 7 carbon atoms, or 1 aprotic or protic oxygen for every 8 carbon atoms, or at least 1 aprotic or protic oxygen for every 12 carbon atoms. Oxygenates also include organic compounds having at least 1 aprotic or protic oxygen for every 16 carbon atoms, or 1 aprotic or protic oxygen for every 20 carbon atoms.

Oxygenates can include, for example, alcohols, ester oils and ether oils. The oxygenate may be included in the refrigeration lubricant as the oil of lubricating viscosity from at least 45 wt %, based on a total weight of the refrigeration lubricant. In some instances, the oxygenate may be present from at least 50 wt % to at least 80 wt %. In other embodiments the oxygenate may be present from at least 80 wt % to at least 90 wt %, or at least 95 wt %. In yet other embodiments, the oxygenate may be present from at least 96 wt %, 97 wt %, 98 wt %, or at least 99 wt %, based on the total weight of the lubricant composition.

Alcohols suitable for use as an oil of lubricating viscosity include monohydric alcohols, for example, ethanol, methanol, propylene alcohol derivatives such as n-butanol and tert-butanol, as well as isopropyl alcohol; higher branched alcohols include isomers of pentanol, hexanol, heptanol, octanol, decanol, dodecanol, tetradecanol, hexadecanol and combinations thereof. Examples of branched alcohols include 2-ethylhexanol, isooctanol, iso-decanol, and isododecanol. Alcohols as used herein also encompass polyols, such as, for example propylene glycol, ethylene glycol, 1,4-butanediol, pentaerythritol, trimethylolpropane.

Ethers suitable for use as an oil of lubricating viscosity include those made from petrochemical feedstocks as well as 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 ether examples include tert-hexyl methyl ether (THEME) and diisopropyl ether. Polyethers are also considered herein in the term “ethers,” including, for example, diethylene glycol dibutyl ether. Low molecular weight oligomers of polyalkylene glycols (i.e. polyalkylene oxides) may also be suitable, including polyethylene glycol (PEG), polypropylene glycol (PPG), and mixed polymers thereof.

Ester oils suitable for use as an oil of lubricating viscosity include, for example, esters of monocarboxylic acids with monohydric alcohols; di-esters of diols with mono-carboxylic acids and di-esters of dicarboxylic acids with monohydric alcohols; polyol esters of monocarboxylic acids and polyesters of monohydric alcohols with polycarboxylic acids; and mixtures thereof. Esters may be broadly grouped into two categories: synthetic and natural.

Synthetic esters suitable for use as an oil of lubricating viscosity may comprise esters of monocarboxylic acid (such as acetic acid, propionic acid, neopentanoic acid, 2-ethylhexanoic acid) and dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids 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 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, dieicosyl 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 those made from C5 to C12 monocarboxylic acids and polyols and polyol ethers such as neopentyl glycol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tripentaerythritol. Esters can also be monoesters of mono-carboxylic acids and monohydric alcohols.

Suitable esters also include esters of hydroxy-substituted carboxylic acids, such as tartaric acid, malic acid, glycolic acid, and hydroxy fatty acids (e.g. 12-hydroxystearic acid) in combination with monohydric alcohols as above.

Natural (or bio-derived) esters refer to materials derived from a renewable biological resource, organism, or entity, distinct from materials derived from petroleum or equivalent raw materials. Natural esters suitable in the heat transfer fluids include fatty acid triglycerides, hydrolyzed or partially hydrolyzed triglycerides, or transesterified triglyceride esters, such as fatty acid methyl ester (or FAME). Suitable triglycerides include, but are not limited to, palm oil, soybean oil, sunflower oil, rapeseed oil, olive oil, linseed oil, and related materials. Other sources of triglycerides include, but are not limited to, algae, animal tallow, and zooplankton.

In some embodiments, the oil of lubricating viscosity is an oxygenate that comprises at least one polyolester (“POE”) oil, wherein the polyolester oil comprises a polyol esterified with at least one (mono)carboxylic acid that has at least 5 carbon atoms. In yet other embodiments, the polyolester oil comprises a polyol esterified with a mixture of (mono)carboxylic acids or their anhydrides, wherein the (mono)carboxylic acids or anhydrides, individually, have 5 to 13 carbon atoms. Suitable ratios of the C5 to C13 carboxylic acids or anhydrides include but are not limited to 95:5 to 5:95. In yet other embodiments the mixture of (mono)carboxylic acids or their anhydrides comprises at least three C5 to C13 carboxylic acid or anhydrides. Suitable polyols include, but are not limited to, trimethylolpropane, dipentaerythritol, neopentylglycol, monopentaerythritol, polypentaerythritol, or combinations thereof. In some embodiments, the POE may comprise esters and/or complex esters of aromatic polycarboxylic acids or their anhydrides. The complex ester may be composed of oligomeric units comprised of polyol (which may include, but is not limited to: trimethylolpropane, dipentaerythritol, neopentylglycol, monopentaerythritol, polypentaerythritol), and polyacid or acid anhydride (which may include, but is not limited to: succinic, glutaric, adipic, citric, trimellitic, pyromellitic), or any mixture thereof. The complex ester may be fully or partially capped with functional (mono)carboxylic acids or (mono)alkylalcohols or singly-capped glycol ethers, or any mixture thereof.

As used herein, “(mono)carboxylic” or “(mono)alkylalcohol”, means the (mono) is optional, i.e. the carboxylic or alkylalochol compounds may be mono or poly. In some embodiments of the disclosed technology, however, only monocarboxylic and/or monoalkylalcohols will be present.

In some embodiments, the oxygenate may comprise an aromatic ester. Suitable aromatic esters are not overly limited. The aromatic hydrocarbon used to make the aromatic ester may have 1 to 5, or 1 to 4, or 2 to 4, carboxylic functional groups. In some embodiments, the aromatic hydrocarbon may be an aromatic carboxylic acid, an aromatic polycarboxylic anhydride, an aromatic polycarboxylic ester, or mixtures thereof. Without limiting the disclosed technology to one theory of operation, it is believed that when the carboxyl group is directly attached to an aromatic ester, the freedom of rotation around that bond is limited. This results in a more rigid molecule with a higher neat viscosity relative to the aromatic esters' molecular weights. In some embodiments, the aromatic ester may be prepared using a polycyclic aromatic acid or acid anhydride, such as 1,8-naphthalic acid.

The (mono)alkylalcohol used to make the aromatic ester may comprise at least one C4 to C15 or C8 to C13 linear or branched alcohol. In some embodiments, the (mono)alkylalcohol may comprise a C10 and C13 alcohol. Suitable ratios of the C10 to C13 alcohol include but are not limited to 95:5 to 5:95. In yet other embodiments, the (mono)alkylalcohol may comprises a branched C10 and branched C13 alcohol, i.e. the (mono)alkylalcohol is a mixture of a C10 and C13 alkyl alcohols and both are branched.

The glycol ether used to make the aromatic ester may comprise alkylene glycols, including mono- and poly-ether alcohols with the general structure of: R1(—O—R2)x—OR3, wherein R1 and R3 can individually be hydrogen or a C1 to C4 hydrocarbyl group; and wherein R2 can be a monoether or a single, alternating, or randomly distributed polyether subunit. Alternatively, the aromatic ester may be a complex ester wherein a doubly uncapped PAG group links two aromatic acids together. In some embodiments, the oxygenate may comprise at least one aromatic ester that is a benzoate ester, phthalate ester, trimellitate ester, pyromellitate ester, or mixtures thereof.

In some embodiments, the oxygenate may comprise at least one polyolester, at least one polyalkylene glycol, at least one polyvinyl ether, or combinations thereof. In yet other embodiments, the oxygenate may comprise at least one polyolester, for example a polyolester derived from the reaction mixture of di-pentaerythritol, heptanoic acid, isononanoic acid, caprylic acid, or capric acid.

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

The branched alkylbenzene may be prepared from a polymer of propylene and benzene as materials using a catalyst such as hydrogen fluoride. The linear alkylbenzene may be prepared from n-paraffin and benzene using the same hydrogen fluoride catalyst. The number of carbon atoms in the alkyl group is preferably from 1 to 30, or from 4 to 20, depending on the desired viscosity for use as a lubricating oil base oil. In some embodiments, the number of alkyl groups in one molecule of the alkylbenzene may be from 1 to 4, or from 1 to 3.

The kinematic viscosity of the alkylbenzene at 40° C. may range from 1 to 50 mm2/s or from 1 to 25 mm2/s. In some embodiments, the alkylbenzene may have kinematic viscosity of at 40° C. of around 4 mm2/s (cSt).

Phosphorus Additive

The refrigeration lubricant may have at least one phosphorus additive. Suitable phosphorus additives may be selected from phosphites, phosphonates, alkylphosphate esters, amine or ammonium phosphate salts.

Phosphorus esters include the reaction products of dihydrocarbon and trihydrocarbon phosphites, e.g., dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite and polypropylene substituted phenol phosphite; metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol diacid; amine salts of alkyl and dialkylphosphoric acids or derivatives including, for example, the amine salt of a reaction product of a dialkyldithiophosphoric acid with propylene oxide and subsequently followed by a further reaction with P2O5; and mixtures thereof (as described in U.S. Pat. No. 3,197,405).

Amine phosphates may be amine salts of (i) monohydrocarbylphosphoric acid, (ii) dihydrocarbylphosphoric acid, (iii) hydroxy-substituted di-ester of phosphoric acid, or (iv) phosphorylated hydroxy-substituted di- or tri-ester of phosphoric acid. The amine salt of a sulfur-free phosphorus-containing compound may be salts of primary amines, secondary amines, tertiary amines, or mixtures thereof.

Amine phosphate salts may be derived from mono- or di-hydrocarbyl phosphoric acid (typically alkyl phosphoric acid), or mixtures thereof. The alkyl of the mono- or di-hydrocarbyl phosphoric acid may comprise linear or branched alkyl groups of 3 to 36 carbon atoms. The hydrocarbyl group of the linear or branched hydrocarbylphosphoric acid may contain 4 to 30, or 8 to 20 carbon atoms. Examples of a suitable hydrocarbyl group of the hydrocarbyl phosphoric acid may 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 combinations thereof. In one embodiment, the phosphate is a mixture of mono- and di-(2-ethyl)hexylphosphate.

Examples of suitable primary amines include ethylamine, propylamine, butylamine, 2-ethylhexylamine, octylamine, and dodecylamine, as well as such fatty amines as n-octylamine, n-decylamine, n-dodecylamine, n-tetradecylamine, n-hexadecylamine, n-octadecylamine and oleyamine. 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 O L, Armeen T, Armeen H T, Armeen S and Armeen S D, wherein the letter designation relates to the fatty group, such as coco, oleyl, tallow, or stearyl groups.

In some embodiments, the at least one phosphorous additive may comprise a phosphate, phosphite, phosphonate, or mixtures thereof. In some embodiments, the at least one phosphorous additive may comprise an aryl phosphate or an aryl phosphate in combination with an alkenyl phosphite. Suitable phosphorous additives include, but are not limited to, C16-C18 alkenyl phosphite, butylated triphenyl phosphate, tricresyl phosphate, dimethyl octadecyl phosphonate, or mixtures thereof. In some embodiments, the refrigeration lubricant may comprise C16-C18 alkenyl phosphite and butylated triphenyl phosphate. The at least one phosphorous 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 a total weight of the compressor lubricant.

In some embodiments, the compressor lubricant may further comprise at least one acid scavenger (for example, glycidyl epoxide) and/or at least one antioxidant (for example, ditertbutyl cresol) and/or at least one metal passivator (for example, benzotriazole).

The composition disclosed herein comprises a chlorine-containing refrigerant blend, which may be a chlorine containing compound and a hydrofluoro olefin (“HFO”). Exemplary chlorine-containing refrigerant blends include R-514A (74.7% HFO-1336mzz-Z, 25.3% trans-1,2-dichloroethylene (t-DCE)).

In some embodiments, the compressor lubricant may further comprise an acid scavenger that is a hydrocarbyl substituted glycidol ether. It 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.

In some embodiments, a refrigeration compressor charged with a chlorine-containing refrigerant blend and a compressor lubricant is disclosed. The compressor lubricant may comprise 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.

In some embodiments, a method of reducing tin corrosion in a compressor system is disclosed. The method may comprise adding at least one phosphorus containing additive to a compressor lubricant. The compressor lubricant may comprise 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 without the at least one phosphorus containing additive disclosed herein.

In some embodiments, additional benefits of the disclosed compressor lubricant comprising a phosphorous containing additive may be realized. For example, wear in the compressor may also be reduced. In other embodiments, the reduction in wear may be measured using ASTM D4172 and/or ASTM D2783. In yet other embodiments, corrosion of other types of metals or alloys in 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 lubricant comprising a phosphorous containing additive may also work well in compressor applications wherein the compressor operates under anaerobic conditions. In some embodiments, the compressor may be a centrifugal compressor.

The amount of each chemical component described is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, that is, on an active chemical basis, unless otherwise indicated. However, unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade.

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 a hydrocarbon character. Examples of hydrocarbyl groups include:

    • hydrocarbon substituents, that is, 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 wherein the ring is completed through another portion of the molecule (e.g., two substituents together form a ring);
    • substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the hydrocarbon nature of the substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);
    • hetero substituents, that is, substituents which, while having a hydrocarbon character, contain other than carbon in a ring or chain otherwise composed of carbon atoms and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. Heteroatoms include sulfur, oxygen, and nitrogen. In general, no more than two, or no more than one, non-hydrocarbon substituents will be present for every ten carbon atoms in the hydrocarbyl group; alternatively, there may be no non-hydrocarbon substituents in the hydrocarbyl group.

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 be different from those that are initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the present invention in its intended use, may not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; the present invention encompasses the composition prepared by admixing the components described above.

The invention herein is useful as a lubricant for refrigeration compressors, which may be better understood with reference to the following examples.

Examples

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

TABLE 1 Lubricant Compositions with Viscosity and Wear Properties EX1 EX2 EX3 EX4 EX5 EX6 EX7 Component wt % VG1 68 VG 100 VG 68 VG 68 VG 68 VG 68 VG 68 carboxylic ester 82.39 91.00 80.61 97.741 80.58 80.58 80.62 alkylbenzene 17.57 6.80 17.23 17.21 17.21 17.22 aryl phosphate2 — 2.00 2.00 2.00 2.00 2.00 1.00 alkenyl phosphite3 — — — 0.10 0.05 0.05 0.10 AS4 (glycidyl epoxide) — 0.09 0.09 0.09 0.09 0.09 0.09 AO5 (ditertbutyl cresol) 0.04 0.1 0.06 0.06 0.06 0.06 0.06 MP6 (benzotriazole) — 0.01 0.01 0.009 0.009 0.009 0.009 Viscosity and wear Viscosity @40° C. D445 59.07 99.93 58.04 56.43 56.47 56.43 56.14 (cST) Viscosity @100° C. D445 8.62 12.18 8.52 8.38 8.35 8.38 8.39 (cST) 4-Ball Wear D4172 0.72 0.27 0.27 0.26 0.25 0.25 0.22 (mm) 4-Ball Load to Fail 40 80 63 63 80 80 63 D2783 126 126 126 126 126 126 160 17.3 26.1 21.3 22.1 26.3 26.3 26.9 Falex Wear 0 122 195 23 19 0 0 Falex Load to Fail (lbs) 1000 1109 1134 1300 1109 1326 1209 1viscosity grade of the baseline lubricant 2butylated triphenyl phosphate 3C16-C18 alkenyl phosphite 4acid scavenger 5antioxidant 6metal passivator

As can been seen in Table 1, the lubricants comprising the phosphorous additive have improved Falex wear and wear properties as measured using ASTM D2783.

Lubricant and R-514A Stability and Compatibility at 125° C. and 175° C.

Five different lubricants are combined with R-514A refrigerant. R-514A is a zeotropic blend of 25.3 wt % trans1,2-dichloroethylene (R-1130(E)) and 74.7 wt % of an olefin (R1336mzzZ). For each lubricant, 2 sets of tubes are prepared, with each set having 4 tubes each. The first three tubes contain the refrigerant and lubricant in a ratio of 2 to 8 (0.4 g. of refrigerant to 1.6 g. of lubricant). One metal catalyst (copper, aluminum, or steel) is also placed in each tube. A fourth tube contains more of the lubricant and refrigerant mixture in the same 2 to 8 ratio (0.5 g. refrigerant and 2.0 g. lubricant) and a metal catalyst.

A visual assessment of both the liquid and metal catalyst is made and recorded. The first set of tubes are then aged at a constant temperature of 125° C. for 7 days. The second set of tubes are aged at a constant temperature of 175° C. for 7 days. After 7 days, the first 3 tubes of both sets are visually examined for changes in lubricant color, opacity, particulate formulation, corrosion of the metal catalysts and copper plating on the surface of the steel catalyst. The visual results are obtained and recorded.

The color of the lubricant is measured according to ASTM D1500. For this color test, the liquid sample is placed in a test container and compared with colored glass disks using a colorimeter and standard light source. The glass discs range in value from 0.5 to 8.0.

The visual results as compared to unaged tubes are described in Table 2 below.

TABLE 2 Visual Results Visual Observations EX1 Liquid (as aged at 125° C. light cloudiness; color = compared to 2.75/2.251; no deposit unaged samples) aged at 175° C. light cloudiness; color = 3.0/2.0; no deposit Metal Coupons aged at 125° C. Cu darker; (as compared to Steel and Al unchanged unaged samples) aged at 175° C. Steel dark brown/red; Cu medium brown; Al unchanged 1The color is compared to an unaged sample and the values are represented as aged/unaged.

As can be seen in the visual test results above, the lubricant without any phosphorous additive with the metal coupons aged at 175° C. for 14 days underwent a color change, indicating the lubricant was reacting with the metal coupons, which is undesirable in a compressor system.

Accordingly, a method of reducing corrosion in a compressor system charged with a chlorine-containing refrigerant is disclosed. The method may comprise adding at least one phosphorus containing additive to a compressor lubricant, wherein the compressor lubricant comprises an oil of lubricating viscosity that has at least one oxygenate. The metal may be at least one of copper, steel or aluminum.

The amount of corrosion reduced 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 alternate embodiments, the compressor may be a centrifugal compressor.

Each of the documents referred to above is incorporated herein by reference, including any prior applications, whether or not specifically listed above, from which priority is claimed. The mention of any document is not an admission that such document qualifies as prior art or constitutes the general knowledge of the skilled person in any jurisdiction. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word “about”. It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements.

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, un-recited elements or method steps. However, in each recitation of “comprising” herein, it is intended that the term also encompass, as alternative embodiments, the phrases “consisting essentially of” and “consisting of,” where “consisting of” excludes any element or step not specified and “consisting essentially of” permits the inclusion of additional un-recited elements or steps that do not materially affect the basic and novel characteristics of the composition or method under consideration.

While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. In this regard, the scope of the invention is to be limited only by the following claims.

Claims

1. A composition comprising a chlorine-containing refrigerant blend, the refrigerant blend comprising a chlorine-containing compound and a hydrofluoro olefin (“HFO”); and

a. a compressor lubricant comprising: i. an oil of lubricating viscosity comprising at least one polyol ester; and ii. at least one phosphorous additive;
 wherein the at least one phosphorous additive is present at 0.1 to 4 wt %, based on a total weight of the compressor lubricant,
 wherein the at least one phosphorous additive comprises an aryl phosphate or an aryl phosphate in combination with an alkenyl phosphite, and
 wherein the aryl phosphate is selected from butylated triphenyl phosphate, tricresyl phosphate, or mixtures thereof.

2. (canceled)

3. (canceled)

4. (canceled)

5. The composition of claim 1, wherein the alkenyl phosphite is a C16-C18 alkenyl phosphite.

6. The composition of claim 1, wherein the compressor lubricant further comprises at least one acid scavenger and/or at least one antioxidant and/or at least one metal passivator.

7. The composition of claim 6, wherein the acid scavenger is a hydrocarbyl substituted glycidol ether.

8. (canceled)

9. The composition of claim 1, wherein the chlorine-containing refrigerant blend comprises R-514A.

10. (canceled)

11. (canceled)

12. The composition of claim 1, wherein the at least one polyol ester is derived from the reaction mixture of di-pentaerythritol, heptanoic acid, iso-nonanoic acid, caprylic acid, or capric acid.

13. The composition of claim 1, wherein the oil of lubricating viscosity further comprises as at least one hydrocarbon oil.

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

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

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

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

18. A refrigeration compressor charged with a chlorine-containing refrigerant blend and the compressor lubricant of claim 1.

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

20. A method of reducing tin corrosion in a compressor system, the method comprising: wherein the compressor lubricant comprises: wherein the compressor system contains a chlorine-containing refrigerant blend, the refrigerant blend comprising a chlorine-containing compound and a hydrofluoro olefin (“HFO”); wherein the at least one phosphorous additive is present at 0.1 to 4 wt %, based on a total weight of the compressor lubricant, and wherein the at least one phosphorous additive comprises an aryl phosphate or an aryl phosphate in combination with an alkenyl phosphite, and wherein the aryl phosphate is selected from butylated triphenyl phosphate, tricresyl phosphate, or mixtures thereof.

a. adding at least one phosphorus containing additive to a compressor lubricant,
b. an oil of lubricating viscosity comprising at least one polyol ester; and

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

22. The method of claim 21, wherein the tin corrosion is reduced as compared to a lubricant without the at least one phosphorus containing additive.

23. The method of claim 21 or 22, wherein wear in the compressor is also reduced.

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

25. The method of claim 20, wherein at least one of steel, copper, or aluminum corrosion is also reduced.

26. The method of claim 20, wherein the compressor operates under anaerobic conditions.

27. The method of claim 20, wherein the compressor is a centrifugal compressor.

Patent History
Publication number: 20260234499
Type: Application
Filed: Feb 15, 2024
Publication Date: Aug 13, 2026
Applicant: The Lubrizol Corporation (Wickliffe, OH)
Inventors: BRIDGETT RAKESTRAW (Midland, MI), DAVID M. PALLISTER (Highland, MI), ANDREW D. SUMNER (Midland, MI), SCOTT MILLER (Midland, MI), ZHANA ADAMS (Flint, MI)
Application Number: 19/156,201
Classifications
International Classification: C10M 171/00 (20060101); C10M 127/06 (20060101); C10M 129/10 (20060101); C10M 129/66 (20060101); C10M 133/44 (20060101); C10M 137/04 (20060101); C10N 20/00 (20060101); C10N 30/10 (20060101); C10N 40/30 (20060101);