KR100249556B1 - Blended Polyol Ester Lubricants for Cooling Heat Transfer Fluids - Google Patents

Abstract

From up to three blend raw materials, several ester mixtures of blocked polyhydric alcohols are prepared that are chlorine free and useful lubricants for fluorocarbon coolant heat transfer fluids, especially coolant 134a (1,1,1,2-tetrafluoroethane). can do.

Description

Blended Polyol Ester Lubricants for Cooling Heat Transfer Fluids

Detailed description of the invention

[Related Applications]

This application is part of a continuing application of co-pending International Application No. PCT / US92 / 04438, filed June 3, 1992 that designates the United States, and is hereby incorporated by reference, except to the extent that it is contrary to the clear description herein. do.

[Technical Field]

The present invention relates to a lubricant base material which may in some cases serve as a complete lubricant; Blended lubricants comprising at least one additive for the purpose of improving high pressure resistance and / or abrasion resistance, corrosion inhibition, etc., together with a lubricant base material that provides primary lubricant properties to the blended lubricants; A refrigerant working fluid comprising a lubricant according to the invention together with a primary heat transfer fluid; And a method for using the materials. Lubricants and lubricant basestocks are generally suitable for use with most or all halogenated carbon refrigerants, and include pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoethane and tetrafluoro It is particularly suitable for use with organic chlorine-free organic refrigeration heat transfer fluids such as ethane, especially 1,1,1,2-tetrafluoroethane.

[Background]

Chlorine-free heat transfer fluids use refrigeration systems because they release less air to the environment than the most commonly used chlorofluorocarbon heat transfer fluids such as trichlorofluoromethane and dichlorodifluoromethane at atmospheric release. Preferred below. However, the widespread commercial use of chlorine free refrigeration heat transfer fluids has been limited by the lack of commercially suitable lubricants. This is particularly lacking in lubricants suitable for one of the most preferred working fluids, usually 1,1,1,2-tetrafluoroethane, commonly known in the art as "refrigerant 134a" or simply "R134a". . Other fluoro substituted ethanes are also preferred working fluids.

The following patents and published patent applications list many general classes and specific examples of polyolesters as useful refrigerant lubricants containing chlorine-free fluoro group-containing heat transfer fluids: US 4,851,144; UK 2 216 541; US 5,021,179; US 5,096,606; WO 90/12849 (Lubrizol); EP 0 406 479 (Kyodo Oil); EP 0 430 657 from AshaiDenka KK; EP 0 435 253 (Nippon Oil); EP 0 445 610 and 0 445 611 (Hoechst AG); EP 0 449 406 (Tonen Corp.); EP 0 458 584 (Unichema Chemie BV); And EP 0 485 979 (Hitachi).

[Initiation of invention]

Except as expressly set forth in the claims and operational examples or otherwise, all numerical quantities expressing reaction and / or conditions of use or amount of material herein are used to define the broadest scope of the invention. In the context of the term "about". However, it is generally preferred to practice the invention within a range corresponding to a defined actual amount.

Various viscosities and physical and chemical properties are needed to achieve optimum lubricant efficiency in many different chillers required for practical use.

For example, a typical type of domestic cooler needs to maintain a cooling temperature in a relatively small, well-insulated space, and the ambient temperature at which waste heat must be released does not vary widely because it becomes a temperature at which one can feel comfortable. Do not. Thus, relatively low power driven compressors are used in such ordinary household coolers and are satisfactory with lubricants having a relatively low viscosity at ordinary human comfort temperatures. This is because the viscosity is not greatly reduced by the temperature since the ambient temperature is not very high. Under these conditions, all of the factors are the same, and low viscosity lubricants reduce power consumption by the machine being lubricated, and the increased cost of power consumption is a low viscosity lubricant because the consumer is more efficient at home use. Is economically desirable.

Automotive air conditioners, on the other hand, may be exposed to outside temperatures below -20 ° C in winter in the standard temperature range of the continental climate, and in the environment of the engine compartment of the car, in summer, reaching much higher temperatures than in the environment of domestic coolers. You will have to release heat. Thus, lubricants with the desired viscosity in domestic coolers are too low to be efficient lubricants for most automotive air conditioner applications at summer operating temperatures. Industrial or commercial large-scale cooling devices, such as ice making plants or facilities for large-scale fast frozen foods, typically require lubricants with a viscosity that is greater than that required for automotive air conditioners because of the high mechanical power requirements. In addition, screw compressors generally require higher viscosity than cooling compressors of the same capacity.

Blocked polyol esters, defined as hydrogen-free organic molecules containing at least five carbon atoms, at least two -OH groups, and bonded directly to carbon atoms having -OH groups, are known in the art to include fluorocarbon refrigerants, in particular chlorine. Cooler types that use coolant are known as high quality lubricant base stocks. The prior art provides single polyol esters or mixtures of such esters prepared by one step reaction of one or more blocked polyols and one or more acids with respect to each particular class of lubricant. They are satisfactory in their performance but exhibit the disadvantages required for a wide variety of individual compounds to cover all of the broadly diverse operating conditions described above.

Under various legislation, new chemicals must undergo the necessary tests before they are properly marketed for general use, and new materials produced by reactions between new mixed components are generally defined as novel compounds. Therefore, all other mixtures of polyol esters produced by a single step reaction must be tested and registered with government agencies in order to be legally marketed in all developed countries by legislation necessary for such registration.

On the other hand, mechanical mixtures of previously registered chemicals are exempt from legal registration requirements, or at least the requirements are relaxed, resulting in lower test costs than would be required for mixtures legally classified as new chemicals. Therefore, it is technically and economically advantageous to mix the smallest possible number of chemical components to provide a lubricant base material suitable for most or all of a wide variety of lubricating conditions.

We have found that good quality lubricants with a wide range of viscosity grades can be obtained by blending at least two of any of the three types of blend raw polyol esters.

Type 1 has the lowest viscosity of the three, (i) 2,2-dimethylpropane-1,3-diol (neopentylglycol, NPG), 2,2-dimethylol-1-butanol (trimethylolpropane, TMP ), An alcohol consisting of a molecule selected from the group consisting of 2,2-dimethylol-1-propanol (trimethylolethane, TME) and 2,2-dimethylolpropane-1,3-diol (pentaerythritol, PE) (Ii) at least 75% of the molecules are selected from the group consisting of butanoic acid, 2-methylpropanoic acid, pentanic acid, 2-methylbutanoic acid and 3-methyl butanoic acid and the remaining acid molecules are C ₆ or less; Esters or ester mixtures prepared by reacting a mixture of an acid molecule selected from the group consisting of monobasic straight-chain carboxylic acids and monobasic branched-chain carboxylic acids of up to C ₉ (of course, all described herein as part of the invention For tangible esters, instead of reacting the acid itself, an acid anhydride It is possible to obtain acid esters, or mixtures of esters, by reacting acid derivatives, such as acid chlorides, and esters of acids with an alcohol having a lower molecular weight than the alcohol required for the ester product according to the invention. Preferred and generally specified herein, esters defined herein produced by reaction with acids can also be obtained by reacting alcohols with the corresponding acid derivatives).

For all these and other types of esters described as part of the present invention, although specifically described as only preferred alcohols and acids, small amounts of impurities present in most commercial or industrial grade products are acceptable in most cases. It should be understood that it can. For example, "commercial di-penta erythritol" includes about 82-90 mole% pure di-pentaerythritol, 5-9 mole% tri-penta erythritol and 5-9 mole% PE, in many cases (Di-pentaerythritol "DPE" is a molecule having six hydroxyl groups and one ether bond, derived from two PE molecules, one hydroxyl group from one PE molecule and the other PE It is derived by removing one hydrogen atom from the hydroxyl group of the molecule, forming water and linking the other two of the original PE molecules with ether bonds.Tri-pentaerythritol, often "TPE", is a group of eight hydroxyl groups and two ethers. A molecule having a bond, and in the case of DPE, it is derived from three PE molecules by similarly removing the water molecules of the two molecules as described above to remove a single water molecule).

In general, however, 25, 21, 17, 12, 8, 5, 3, 2, 1, 0.5 or 0.2% (more preferred in order) of the hydroxyl groups in the alcohol mixture or the carboxyl groups in the acid mixture specified herein It must be part of any molecule other than the molecule specified for each type of blend stock. As noted above, the percentage of specific chemical molecules or fragments, such as the percentage of hydroxyl and carboxyl groups, should be understood as numerical percentages, which percentages are chemical equivalent percentages by the avogadro number of each specific chemical fragment considered to be a single chemical equivalent. Is numerically equivalent to

At least 45, 62, 78, 89 or 95% (gradually preferred in sequence) of the alcohol molecules used to prepare the lowest viscosity Type 1 ester blend raw materials used according to the invention are TMP, PE or their Mixture. At least 51, 67, 85, 92, 97 or 99% (preferably in order) acid molecules reacted to prepare the Type 1 ester blend raw material are selected from acids containing C ₅ per molecule and At least 60, 72, 84, 93 or 97% pentanoic acid (straight chain) of the total C ₅ molecules.

The degree of desirability can be determined by considering a wide variety of factors measured experimentally, including the following generalization: Branched acids impart lower viscosity to the ester compared to unbranched acids with the same number of carbon atoms, but humans feel comfortable At higher ambient temperatures or at any lower temperature, which generally gives a higher absolute viscosity. Alcohols with two hydroxyl groups produce esters with a lower viscosity than alcohols with three hydroxyl groups. Acids with six or more carbon atoms produce esters with higher viscosity than acids with fewer carbon atoms, and acids with four carbon atoms, especially less than four carbon atoms, are easier to use than acids with more carbon atoms during use. Hydrolyzed; Such hydrolysis is undesirable because the acid produced by the hydrolysis promotes corrosion of at least some types of metal surfaces that are lubricated. In addition, corrosion of carboxylic acids on most metals found in refrigeration compressors increases as the number of carbon atoms in the acid molecules decreases.

Due to these various factors, it has been found that esters obtained by reacting TMP and / or PE with pentanoic acid are close to those ideal as low viscosity blend raw materials, since the esters are as viscous as generally required in conventional cooling machines. Under low, normal atmospheric pressure it can be mixed in most proportions with most or all fluorocarbon refrigerants over a range of temperatures ranging from at least -55 ° C. to the boiling point of the fluorocarbon refrigerant and the higher temperatures attainable in the compression stage of the cooler. It can dissolve other high viscosity and low solubilized blocked polyol esters and is very effective in reducing the viscosity of different types of blended feedstocks, and it is more resistant to corrosion than esters obtained with acids having less than 5 carbon atoms per molecule. Because it promotes less.

The second type of blend raw material according to the invention has a viscosity of medium viscosity, (i) TMP; It has four hydroxyl groups and one ether bond, typically derived from two TMP molecules, which removes one hydroxyl from one TMP molecule and one hydrogen from the other TMP molecule's hydroxyl group to form water and Di-trimethylolpropane (DTMP) derived by ether bonding two residues from a TMP molecule; PE; And an alcohol molecule mixture selected from the group consisting of DPE, and (ii) all linear and branched mono and dibasic carboxylic acids of C ₄ to C ₁₂ , wherein (a) at least 3% in the mixture , Or 7, 10, 14, 21 or 28% (preferably in order) acid molecules are 2-methylbutanoic acid and / or 3-methylbutanoic acid (both abbreviated iC ₅ ), and (b) The ratio of% of acid molecules in the mixture that is branched and less than or equal to C ₆ to% of acid molecules in the mixture that is greater than or equal to C ₈ is about 1.56 or less, preferably 1.21, more preferably 1.00 or less, and (C) The percent acid molecule in the mixture containing at least 9 unbranched carbon atoms is about 81%, preferably 67% or 49% or less, and (d) at least 20%, or at least 29, 35 in the (d-1) mixture. Or 41% (gradually preferred in sequence) acid molecules are trimethylhexanoic acid, most preferably 3,5,5-trimethylhexanoic acid, up to about 14% of the acid mixture, or up to 10, 7, 3,1, or 0.4% (gradually preferred), is part of the dibasic acid, and in the acid mixture 2% or less of the carboxyl group; Preferably at most 1%, more preferably at most 0.5% is part of an acid molecule having two or more carboxyl groups, or (d-2) at least 3, or at most 18% in an acid mixture of at least 5, 7, 10 or 14 Carboxyl groups of% to 18% (preferably in sequence) are part of the dibasic acid molecules, and less than or equal to about 2%, preferably 1%, more preferably 0.5% or less of the carboxyl groups in the acid mixture. Is part of an acid molecule having a carboxyl group, and at least about 82% of the total, or at least 85, 89, 93, 96, or 99% (gradually preferred) monobasic acid molecules in the acid mixture are C ₅ or C ₆ , preferably Is an ester or ester mixture prepared by reacting with an acid molecule mixture selected under conditions having a C ₅ carbon atom.

Preferably in the mixture reacted to produce this type 2 blend stock, at least 60, 75, 85, 90, 95 or 98% (more preferred in sequence) of hydroxyl groups in the mixture are part of the PE molecule. Independently, in the reaction mixture to prepare such a type 2 blend stock, at least 60, 75, 85, 90, 95 or 98% (more preferred in sequence) of monobasic acid molecules in the acid mixture are C ₁₀ or less carbon sources. Consisting of molecules having a valence, wherein 60, 75, 85, 90, 95 or 98% (more preferred in sequence) of the dibasic acid molecules in the acid mixture are C ₁₀ or less, preferably C ₅ -C ₇ Branches are made of molecules. Most preferably, at least 60, 75, 85, 90, 95 or 98% (preferably in order) monobasic acid molecules in the acid mixture consist of C ₅ or C ₉ molecules.

As with type 1 blend stocks, priorities for type 2 blend stocks are based on experimentally determined generalizations. In order to determine the preferred midrange viscosity corresponding to ISO grade about 32-46, it is desirable to have a substantial alcohol fraction having at least four hydroxyl groups. Among commercially available blocked alcohols that meet these conditions, PE is less expensive than DTMP and increases the hygroscopicity of the ester in DTMP and is free of ether bonds that cause undesirable corrosion on lubricated metal surfaces. Alcohols having four or more hydroxyl groups produce esters whose viscosity is higher than the optimum viscosity, although some such esters may be acceptable, and mixtures comprising them may be less expensive. Commercial grade PEs contain significant amounts of DPE and are somewhat less expensive than purified PE. If cost is not an important condition, it is desirable to remove all or most of the DPE from the predominant PE mixture of the alcohol used to prepare the ester to minimize the change in insolubility of the ester mixture portion at low temperatures.

In order to obtain type 2 esters with sufficient viscosity, a significant fraction of the acid molecules reacted need to have C ₈ or more carbon atoms or dibasic acids. Dibasic acids are less preferred. In order to avoid excessive viscosity, it should be used in somewhat small amounts, since the reaction between an acid molecule and an alcohol molecule having at least two functional groups can form oligomers or polymers of high molecular weight and very high viscosity. Indeed, the amount of dibasic acid that can be effectively used in the acid mixture reacted to produce the type 2 blend raw materials used according to the present invention provides at least one dibasic group to combine two alcohol molecules each in the reacted alcohol mixture. Substantially less than sufficient. Thus, when this amount of dibasic acid is used, some alcohol molecules are bound together in the ester from which they are formed, and some are not: esters with two or more alcohol residues are much more viscous and generally a mixture with only one alcohol residue It is less soluble in the fluorocarbon coolant fluid than other esters in it, increasing the risk of undesirable phase separation during ester use.

As mentioned above, when substantially monobasic acids are used to prepare the esters in the type 2 blend stock, a substantial fraction of the acid molecules must have at least 8 carbon atoms to achieve sufficient viscosity in the mixture. The solubility of esters in the fluorocarbon coolant fluid by acids of this length is lower than that by esters with shorter acids, and this decrease in solubility is particularly pronounced, especially in straight chain acids, so that a substantial fraction of these long chain acids is generally branched. There is a need; Such long chain acids may be effective as they are “balanced” with solubility not equal to or much less than the same fraction of branched acids having C ₅ or C ₆ . When the number of carbon atoms per molecule is 9 or more, branching by itself is not sufficient to obtain a suitable solubility, and an upper limit on the fraction of these acids is required independently. In general, the minimum amount of particularly advantageous iC ₅ acid is characterized to assist in dissolving the ester moiety in the mixture containing dibasic acids or dibasic acids having at least 8 carbons.

For efficiency and economics of the process, C ₅ or C ₉ monobasic acids are the most preferred components and can be combined with each other to obtain a combination of solubility and viscosity properties that is more suitable than others for most applications. Trimethylhexanoic acid with three methine branched chains produces the most soluble esters among readily available C ₉ acids (generally, methine branched chains do not increase viscosity excessively because of the large number of carbons in other branched functional groups). Most effective in increasing solubility). Branched chains on the alpha carbon to the carboxyl groups increase the difficulty of the esterification reaction and are less effective at increasing solubility than those at the farther sites. The most commercially available branched C ₉ acids, including 88-95 mole% of 3,5,5-trimethylhelic acid and the remainder of up to 1 mole% of other branched C ₉ monobasic acids, are at least as effective as others. It is preferred because it is economical as a source of C ₉ monobasic acids.

Blend raw material esters or ester mixtures (“type 3”) having a third highest viscosity used in accordance with the present invention include (i) TMP; DTMP; PE; DPE; TPE; Tri-trimethylol propane (hereinafter referred to as "TTMP"), ie a group consisting of molecules derived from three TMP molecules by removing two molecules of water as in the TPE and having two ether bonds and five hydroxyl groups The alcohol molecule mixture selected from (ii) a straight or branched chain monobasic carboxylic acid having C ₅ or C ₆ carbon atoms, a single or a plurality of branched chain monobasic carboxylic acids of C ₇ to C ₁₃ and C ₄ to Prepared by reacting with a mixture of acid molecules selected from the group consisting of C ₁₀ dibasic carboxylic acids; (a) an acid mixture in which (a-1) at least 19%, or gradually preferred, 23, 27, 29 or 33% of the carboxyl groups are part of the dibasic acid molecule and (a-2) is part of the monobasic acid molecule. At least 75%, or increasingly preferred, 82, 89, 95, or 98% of the carboxyl groups are part of the C ₅ monobasic acid molecule, and (a-3)% of the carboxyl groups in the acid mixture that is part of the iC ₅ acid are part of the dibasic acid. At least 34, or gradually preferred, at least 45, 57, 70, 85, 93, 108, 119, 130 or 135% of the carboxyl groups in the acid mixture, or (b) 14% of the carboxyl groups in the acid mixture (b-1) 10, 7, 3, 1 or 0.4% is now part of a dibasic acid, and (b-2) at least 82% of the carboxyl groups in the acid mixture, or 84, 88, 92 or 96% is gradually preferred. Is part of a monobasic acid containing at least C ₉ carbon and at least one branched chain, (b-3) At least 60%, or gradually preferred, of 71, 84, 88, 92 or 96% of the carboxyl groups in the acid mixture is a part of the trimethyl hexane acid molecule, most preferably a part of the 3,5,5-trimethylhexane acid molecule. It is made by reacting under one of the conditions (a) and (b).

Preferably, 60, 75, 85, 90, 95 or 98% (gradually preferred in order) of the carboxyl groups in the mixture reacted to enhance the type 3 blend raw material are part of the PE or DPE molecules, of which 50%, preferably at least 80% are PE molecules.

The above description of each of the acid and alcohol mixtures that reacts to produce one of the three blocked polyol ester blend raw materials is merely a mixture of acids or alcohols that actually react to produce the esters and is in contact with each other for the reaction. This does not mean that the mixture of acids or alcohols has the same composition as the mixture that is actually reacted. In fact, if the amount of acid initially charged in the reaction mixture is sufficient to provide 10-25% excess of acid over the equivalent of alcohol reacting with the acid, the reaction between the alcohol (s) and acid (s) used is more It has been found to proceed effectively (equivalent of acid is defined as the amount containing 1 g equivalent of carboxyl groups for the purposes of the present invention, while the equivalent of alcohol is that amount containing 1 g equivalent of hydroxyl groups). When the acid component to be reacted contains both one equivalent of acid and a high acid value of acid, the excess is preferably produced by monovalent acid alone. The composition of the acid mixture that is actually reacting can be determined by analysis of the acyl group content of the product ester mixture.

In preparing a mixture of most or all esters and esters preferred for use as blend raw materials according to the invention, the reacting acid (s) will have a lower boiling point than the reacting alcohol (s) and product ester (s). will be. When the above conditions are obtained, it is preferable to remove any excess acid maintained at the end of the esterification reaction by distillation by distillation, most preferably at a low pressure such as 1 to 5 torr.

After this vacuum distillation, the product is often prepared for use as a lubricant blend raw material according to the present invention. If further purification of the product is desired, the content of free acid in the product after the first vacuum distillation can be determined by treatment with an epoxy ester as set forth in US Pat. No. 3,485,754, or with lime, alkali metal hydroxides or alkali metal carbonates. It can be further reduced by neutralization with such a suitable alkaline material. If treatment with epoxy esters is used, excess epoxy esters can be removed by a second distillation under very low pressure, while the reaction product between the epoxy esters and the residual acid can remain in the product without hazard. If neutralization with alkali is used as the purification method, before using the product as a lubricant and / or basic raw material according to the invention, removing small amounts of soap and unreacted excess alkali produced from excess fatty acids neutralized by alkali. For this reason, continuous washing with water is very preferable.

The ester basestock according to the present invention is composed of two or more of the above blend raw materials types 1, 2 and 3 in an amount of at least 5, preferably at least 10, more preferably at least 15% by weight. In order to have the most practical value, it is preferred that the Type 1 blend raw material has a viscosity of at least 18 centistokes at 40 ° C. and more preferably at most 16, and for the same reason, type 3 blend raw materials have a viscosity of at least 90 centistokes at 40 ° C. It is preferable to have a viscosity. It is also preferred that the blend lubricant ester base raw material according to the invention has a viscous V _B at 40 ° C., which viscosity is the lowest and highest viscosity of each of the two or three blend raw materials from which the blend ester is composed, ie 40 The relationship is as follows for V _L and V _H at ° C:

(1 + x) V _L ≤ V _B ≤ (1-x) V _H

Wherein x has a value of 0.02, 0.04, 0.07, 0.10, 0.15 or 0.20 (gradual preferred values).

In addition, the blend raw material according to the invention is preferably selected such that a blend having an ISO grade of 22 to 68, or more preferably 16 to 100, is prepared from the three blend raw materials.

Under some conditions of use, the described esters fully function as lubricants. However, in general, conventional additives such as oxidative and thermal stability improvers, corrosion inhibitors, metal deactivators, lubricity additives, viscosity improvers, flow and / or melting point depressants, cleaning agents, dispersants, antifoaming agents, antiwear agents and high pressure resistant additives are It is preferred to contain other substances. Many additives have multiple functions. For example, certain additives confer both wear resistance and high pressure resistance, or function as metal deactivators and corrosion inhibitors. In addition, all additives do not exceed 8% by weight, preferably 5% by weight of the total lubricant formulation.

Effective amounts of the additives are generally 0.01 to 5% of an antioxidant, 0.01 to 5% of a corrosion inhibitor component, 0.001 to 0.5% of a metal deactivating component, 0.5 to 5% of a lubricant additive, and a 0.01 to 2% viscosity improving agent, respectively. And pour point and / or melting point lowering agents, 0.1 to 5% of detergents and dispersants, 0.001 to 0.1% of antifoaming agents and 0.1 to 2% of antiwear agents and high pressure resistant components, respectively. All of the above percentages are% by weight based on the total lubricant composition. More or less than the above additive amount may be more suitable for a particular situation, a single molecular type or a mixture thereof may be used as each type of additive component. In addition, the examples described below are exemplary and do not limit the scope of the present invention according to the appended claims.

Examples of suitable antioxidant and heat stability improvers include diphenyl-, dinaphthyl-, and phenylnaphthyl-amines, such as N, N'-diphenyl phenylenediamine, p, wherein phenyl and naphthyl groups may be substituted. -Octyldiphenylamine, p, p-dioctyldiphenylamine, N-phenyl-1-naphthyl amine, N-panyl-2-naphthyl amine, N- (p-dodecyl) phenyl-2-naphthyl amine , Di-1-naphthylamine and di-2-naphthylamine; Phenothiazines such as N-alkyl phenothiazines; Amino (bisbenzyl); And 6- (t-butyl) phenol, 2,6-di- (t-butyl) phenol, 4-methyl-2,6-di- (t-butyl) phenol, 4,4'-methylenebis (-2 Blocked phenols such as, 6-di- {t-butyl} phenol) and the like.

Examples of suitable copper metal deactivators include imidazole, benzamidazole, 2-mercapto benzthiazole, 2,5-di-mercaptothiadiazole, salicylidin-propylenediamine, pyrazole, benzotriazole, tol Lutriazole, 2-methylbenzimidazole, 3,5-dimethyl pyrazole and methylene bis-benzotriazole. Preference is given to benzotriazole derivatives. Other examples of more common metal deactivators and / or preservatives include organic acids and esters, metal salts and anhydrides thereof, such as, for example, N-oleyl-sarcosine, sorbitan monooleate, lead naphthenate, dode Cenyl-succinic acid and partial esters and amides and 4-nonylphenoxy acetic acid; Amine salts of primary, secondary and tertiary aliphatic and cycloaliphatic amines, and organic and inorganic acids such as, for example, oil soluble alkylammonium carboxylates; Heterocycle nitrogen containing compounds such as, for example, thiadiazoles, substituted imidazolines and oxazolines; Quinoline, quinone and anthraquinone; Propyl gallate; Barium dinonyl naphthalene sulfonate; Alkenyl succinic anhydrides or esters and amide derivatives of acids, dithiocarbamates, dithio phosphates; Amine salts of alkyl acid phosphates and derivatives thereof.

Suitable lubricants include long chain derivatives of neutral oils and fatty acids such as esters, amines, amides, imidazolines and borates.

Suitable viscosity modifiers include polymethacrylates, copolymers of vinyl pyrrolidone and methacrylates, polybutenes and styrene-acrylate copolymers.

Suitable pour point and / or melting point depressants include polymethacrylates such as methacrylate-ethylene-vinyl acetate copolymers; Acrylated naphthalene derivatives; And Friedel-Crafts catalyst condensation products of naphthylene or nol and urea.

Suitable detergents and / or dispersants include polybutenyl succinic acid amides; Polybutenyl phosphonic acid derivatives; Long-chain alkyl substituted aromatic sulfonic acids and salts thereof; And metal salts of alkyl sulfides, alkyl phenols and condensation products of alkyl phenols with aldehydes. Examples of suitable antifoaming agents include silicone polymers and some acrylates. Examples of suitable antiwear and high pressure resistant agents include sulfided fatty acids and fatty acid esters such as octyl sulfide sulfide; Sulfide terpenes; Sulfide olefins; Organic polysulfides; Amine phosphates, aryl acid phosphates, dialkyl phosphates, aminedithio phosphates, trialkyl and triaryl phosphorothionates, trialkyl and triaryl phosphines, and dialkyl phosphates such as amines of monohexyl phosphate esters Organic phosphorus derivatives including salts, amine salts of dinonylnaphthalene sulfonate, triphenyl phosphate, trinaphthyl phosphate, diphenyl cresyl and dicresyl phenylphosphate, naphthyl diphenyl phosphate, triphenylphosphorothionate; Dathiocarbamates such as antimony dialkyl dithiocarbamate; Chlorinated and / or fluorinated hydrocarbons and xanthates.

Under certain operating conditions, polyether polyol types comprising predominantly most conventional lubricant base materials known to be useful as fluorocarbon cooling fluids are considered to be somewhat unstable or incompatible with the most useful lubricant additives in lubricants. do. Thus, in one embodiment of the present invention, lubricants and lubricant basestocks that are substantially free of such polyether polyols are preferred. "Substantially free" means that the material is about 10% by weight or less, preferably 2.6% by weight or less, more preferably 1.2% by weight or less.

A first embodiment according to the invention is a cooling fluid comprising both a suitable heat transfer fluid such as fluorocarbon and the lubricant according to the invention. Preferably the cooling fluid and the blend lubricant should have chemical properties, and the fluid is uniformly ie visually detectable in the entire operating temperature range in which the cooling fluid is exposed during operation of the cooling system in which the cooling fluid is used. It is present in proportions to each other that remain intact. This temperature range of use may vary from -60 ° C to + 175 ° C. It is suitable that the working fluid is maintained in a single phase up to + 30 ° C., but preferably in a single phase up to 40, 56, 71, 88 or 100 ° C. Similarly, it is suitable to maintain the single phase when the working fluid composition is cooled to 0 ° C., but more preferably the single phase is maintained even when cooled to −10, −20, −30, −40, or −55 ° C. It is good to be. Single phase mixtures with chlorine-free fluorocarbon cooling fluids can be obtained with suitable and preferred types of blend esters, most preferred if the single phase is maintained at a wide range of temperatures. In order for the blend to exhibit a single phase aspect, it is not necessary for the blend raw material itself to exhibit a single phase. For example, tetraesters of PE with 3,5,5-trimethylhexanoic acid are rarely miscible with coolant 134a, but blends of 45% by weight of such tetraesters and 55% by weight of pentanoic acid with PE tetraesters have a broad temperature range. Shows a single phase pattern with R134a.

Although it is difficult to predict exactly how much of the lubricant will be mixed with the heat transfer fluid to form the working fluid, it is most desirable that the lubricant composition forms a single phase at all proportions with the heat transfer fluid over the temperature range. However, this is a very stringent requirement and it is sufficient to maintain a single phase over the entire temperature range for working fluid mixtures containing up to 1% by weight of lubricant according to the invention. It is more preferred to exhibit single phase behavior over a range of temperatures for mixtures containing up to 2, 4, 10, and up to 15% by weight or up to 70 or 80% by weight of lubricant.

In some cases, a single phase aspect is unnecessary. The term "miscible" is a term used in the field of refrigeration lubricants, hereinafter having some meaning of "miscible at all ratios", ie having two phases, but at least gently with a uniform dispersion upon gentle mechanical agitation. The exception is when they can be mixed. A type of refrigeration compressor is designed to work satisfactorily with this miscible mixture of cooling fluid and lubricant. On the other hand, mixtures in which aggregation or significant thickening occurs and form two or more phases cannot be used commercially and are referred to herein as "immiscible." Any of the mixtures described below are described as comparisons and are not examples according to the invention.

Another embodiment of the present invention relates to the use of a lubricant blend according to the invention as a lubricant as a whole lubricant or as a lubricant raw material in a method of operating the chiller in such a way that the lubricant is in contact with the cooling working fluid.

Preferred ranges of viscosity and viscosity change, taking into account the temperature for the lubricant composition according to the invention, are generally used in conventional lubricants of the art used in cooling systems together with heat transfer fluids, in particular fluorocarbon and / or chlorofluorocarbon heat transfer fluids. Is the same as Generally, coolants according to the present invention have an International Organization for Standards (ISO) viscosity rating between 10 and 1000. Viscosity ranges for some ISO viscosity grades are shown in Table 1.

TABLE 1

Hereinafter, the Examples according to the present invention will be described in comparison with Comparative Examples.

[General Esthetic Synthesis Process]

The reacted alcohol and acid are charged into a round flask equipped with a stirrer, thermometer, nitrogen sparge, condenser and circulation trap together with a suitable catalyst such as dibutyltin diacetate, tin oxalate, phosphoric acid and / or tetrabutyl titanate. . The acid is charged in about 15 mol% excess of the alcohol. The catalytic amount is from 0.02 to 0.1% by weight of the total acid and alcohol weights.

The reaction mixture was heated to a temperature of about 220-230 ° C. and water from the reaction was collected in a trap while returning the resulting reflux to the reaction mixture. The partial vacuum was maintained as necessary in the reaction mixture such that a reflux rate of 8-12% of the original reaction mixture was obtained per hour.

The reaction mixture is sometimes sampled to determine the hydroxyl value and this hydroxyl value drops to less than 15.0 mg KOH per gram of mixture for reactions containing divalent acid or up to 5.0 mg KOH per gram of mixture for other reactions. After stirring, most of the excess acid while maintaining the reaction temperature was removed by distillation after applying a maximum vacuum corresponding to an allowable pressure of about 0.05 Torr obtained by the apparatus. The reaction mixture was cooled down and any remaining acidity was removed by treatment with lime, sodium hydroxide, or epoxy esters, if necessary. The resulting lubricant or lubricant basestock was dried and filtered before blending and phase compatibility testing.

[General Procedure of Phase Compatibility Test]

1 ml of the lubricant to be tested was placed in a graduated glass test tube that was heat shock resistant, 17 ml in diameter and 145 mm long. The test tube was closed and placed in a cooling bath adjusted to -29 ± 0.2 ° C. After the tubes and contents were equilibrated in a cooling bath for 5 minutes, sufficient cooling fluid was added to bring the total volume to 10 ml.

At least 5 minutes after the addition of the working fluid, the tubes and contents are equilibrated in a cooling bath and, if necessary, the contents of the tubes are visually observed to observe phase separation while the contents are stirred. If no phase separation occurs, shake to determine whether the formulation is miscible or wholly.

If phase separation does not occur at -29 ° C, the temperature of the cooling bath is lowered at a rate of 0.3 ° C per minute until phase separation is observed. If the temperature at which phase separation is first observed is within the range of the cooling apparatus used, record as the insoluble onset temperature.

[Composition of Blend Raw Material]

The blend raw material of the type 1 described above is an acid molecule mixture containing 99.4% of PE and the remainder of DPE molecules, an alcohol mixture of 99.6% of pentanoic acid (n-valeric) and mainly 2-methyl butanoic acid. Prepared by reaction with. This type 1 blend raw material has an ISO rating of 15.

The first blend of type 2 described above comprises an alcohol mixture of 99.4% PE and most of the remaining DPE molecules, 46.7% pentanoic acid (n-valeric), 21.5% 2-methylbutanoic acid and 31.6% Was prepared by reacting an acid molecule mixture comprising 3,5,5, -trimethylhexanoic acid and other branched C ₉ monobasic acids as the remainder. This type 2-1 blend raw material has an ISO rating of 32.

The second blend of type 2 described above comprises an alcohol mixture of 99.4% PE and most of the remaining DPE molecules, 66.8% pentic acid (n-valeric), 28.4% 2-methylbutanoic acid and 4.6%. It was prepared by reacting with an acid molecule mixture containing adipic acid and methylbutanoic acid as the rest. This type 2-2 blend raw material has an ISO rating of 32.

The first blend of type 3 consisted of a mixture of alcohol molecules with 99.4% PE and the remainder mostly DPE molecules, 61.9% pentanoic acid (n-valeric acid), 27.8% 2-methylbutanoic acid and 10.2% sub Prepared by reaction with an acid molecule mixture comprising dific acid and 3-methylbutanoic acid as remainder. This type 3-1 blend raw material has an ISO rating of 100.

The second blend of type 3 contains 99.4% PE, the remainder of which is mostly DPE molecules, containing 90% of 3,5,5-trimethylhexanoic acid and the other branched C ₉ monobasic acids as the remainder. Prepared by reaction with an acid molecule mixture. This type 3-2 blend raw material is solid at room temperature and therefore does not have a corresponding ISO grade.

[Examples of Specific Blend Esters]

Examples of the blend esters according to the invention made from the blend raw materials are shown in Table 2.

TABLE 2

Claims (20)

A composition comprising a blend mixture comprising at least two of at least two of each of the following Type 1, Type 2, and Type 3 blend raw materials, each of a different type of ester, suitable for use as a lubricant or lubricant base material: Type 1: (i) an alcohol molecule mixture consisting of molecules selected from the group consisting of NPG, TMP, TME and PE, and (ii) at least 75% of the molecules are butanoic acid, 2-methylpropanoic acid, pentanic acid, 2-methyl A mixture of acid molecules selected from the group consisting of butanoic acid and 3-methylbutanoic acid and the remaining acid molecules selected from the group consisting of C ₆ or less monobasic straight carboxylic acids and C ₉ or less monobasic branched carboxylic acids; Esters or ester mixtures prepared by reacting and having a viscosity at 40 ° C. of 18 centistokes or less; Type 2: (i) an alcohol molecule mixture selected from the group consisting of TMP, DTMP, PE and DPE, and (ii) a group consisting of all straight and branched chain monobasic and dibasic carboxylic acids of C ₄ to C ₁₂ A mixture of acid molecules selected from (a) at least 3% of the acid molecules in the mixture are iC ₅ acids, and (b) acid molecules in the mixture at least C ₈ unbranched to% of acid molecules in the mixture, which are branched up to C ₆ The percentage of% is less than or equal to about 1.56, (c) The percentage of acid molecules in the mixture containing at least 9 carbon atoms, branched or unbranched, is less than or equal to about 81%, and (d) 20% in the mixture (d-1). The above acid molecule is one of trimethylhexanoic acid, about 14% or less of the carboxyl group in the acid mixture is part of the dibasic acid, or (d-2) 3% to 18% of the carboxyl group in the acid mixture is part of the dibasic acid molecule, Less than about 2% of the carboxyl groups in the acid mixture have two or more It is part of acid molecules with a group, the acid mixture in at least about 82% of monobasic acid molecules are produced by acid molecule mixture and the reaction to satisfy the condition that has a carbon atom of a C ₆ or less, a viscosity at 40 ℃ 18 cm Stock Esters or ester mixtures greater than and less than 90 centistokes; And Type 3: (i) an alcohol molecule mixture selected from the group consisting of TMP, DTMP, PE, DPE, TPE, and TTMP, and (ii) a straight or branched chain monobasic carboxylic acid having C ₄ or C ₆ carbon atoms. A mixture of acid molecules selected from the group consisting of C ₇ to C ₁₃ single or plural branched monobasic carboxylic acids and C ₄ to C ₁₀ dibasic carboxylic acids, comprising: (a) (a-1) acid At least about 19% of the carboxyl groups in the mixture are part of the dibasic acid molecule, (a-2) at least 75% of the carboxyl groups in the acid mixture that are part of the monobasic acid molecule are part of the C ₅ monobasic acid molecule, and (a-3) iC ₅ % or more of the carboxyl groups in the acid mixture which are part of the ₅ acid is part of a dibasic acid, or (b) 14% or less of the carboxyl groups in the acid mixture is part of the dibasic acid, (b a-2) more than 82% of the carboxyl acid mixture C ₉ of carbon and at least one A part of a monobasic acid containing a branched chain, wherein (b-3) at least 60% of the carboxyl groups in the acid mixture are part of the trimethyl hexanoic acid molecule, i.e. satisfying one of the conditions (a) or (b) above An ester or mixture of esters prepared by reacting with a mixture of acid molecules and having a viscosity at 40 ° C. of at least 90 centistokes. The method of claim 1, Type 1: (i) an alcohol molecule mixture in which at least about 62% of the molecules are totally TMP or PE, and (ii) at least about 67% of the molecules are selected from the group of acids containing C ₅ per molecule, such C ₅ acid molecules At least about 60% of is prepared by reacting with an acid mixture that is pentanic acid; Type 2 is: (i) a mixture of alcohol molecules in which at least about 75% of the molecules are PE molecules, and (ii) a mixture of acid molecules in which at least about 75% of the acid molecules each contain C ₁₀ or less, (a) a mixture At least about 7% of the acid molecules in the mixture are iC ₅ and (b) the ratio of the% of acid molecules in the mixture that is not branched to C ₈ or more to about% of the acid molecules in the branched and C ₆ or less mixture is about 1.21 or less, (c ) The percentage of acid molecules in a mixture containing at least 9 carbon atoms, branched or unbranched, is less than about 67%, and (d) (d-1) more than about 35% of the total acid molecules in the mixture are trimethylhexanoic acid. Up to about 10% of the carboxyl groups in the acid mixture are part of a dibasic acid molecule, or (d-2) at least 7% of the carboxyl groups in the acid mixture are part of a dibasic acid molecule, and at least about 89% of the total monobasic acid in the acid mixture Acid molecule mixtures that satisfy the condition that the molecule has 5 or 6 carbon atoms It is produced by the reaction; Type 3: (i) a mixture of alcohol molecules in which at least about 75% of the total are PE or DPE molecules, (ii) as a mixture of acid molecules, and (a) at least about 23% of carboxyl groups in the (a-1) acid mixture Is part of a dibasic acid molecule, and (a-2) at least about 89% of the carboxyl groups in the acid mixture that is part of a monobasic acid molecule are part of a monobasic acid molecule of C ₅ , and (a-3) an acid that is part of an iC ₅ acid. At least about 57% of the carboxyl groups in the acid mixture, wherein% of the carboxyl groups in the mixture are part of the dibasic acid molecule, or (b) up to about 10% of the carboxyl groups in the acid mixture (b-1) are part of the dibasic acid, and (b- 2) at least about 84% of the carboxyl groups in the acid mixture are part of a monobasic acid having at least C ₉ and at least one branched chain, and (b-3) at least about 71% of the total carboxyl groups in the acid mixture are part of the trimethylhexanoic acid molecule; Crude, wherein at least about 60% of the carboxyl groups in the acid mixture are part of 3,5,5-trimethyl hexanoic acid molecules Composition as that prepared by the acid mixture and the reaction to meet the characteristics. The method of claim 2, Type 1 are: (i) the total of at least about 78% of molecules are TMP or PE the alcohol molecule mixture, (ii), and molecules of greater than about 85% is selected from an acid group containing a C ₅ per molecule, these C ₅ acid At least about 72% of the molecule is prepared by reacting with an acid mixture that is pentanic acid; Type 2 is: (i) a mixture of alcohol molecules in which at least about 85% of the molecules are PE molecules, (ii) a mixture of acid molecules in which at least about 85% of the acid molecules each contain C ₁₀ or less, (a) a mixture At least about 10% of the acid molecules in the mixture are iC ₅ , and (d) at least about 35% of the acid molecules in the mixture (d-1) are one type of trimethylhexanoic acid, and at least about 3% of the molecules in the acid mixture are at least one molecule. Having a carboxyl group or (d-2) at least about 7% of the carboxyl groups in the acid mixture are part of the C ₄ to C ₁₀ dibasic molecules, and at least about 93% of the total monobasic molecules in the acid mixture are 5 or 6 carbon sources Prepared by reacting with an acid molecule mixture that satisfies the conditions having a molecule; Type 3: (i) a mixture of alcohol molecules in which at least about 85% of the total is PE or DPE molecules, (ii) as a mixture of acid molecules, and (a) at least about 27% of carboxyl groups in the acid mixture (a) Is part of a dibasic acid molecule, and (a-2) at least about 89% of the carboxyl groups in the acid mixture that is part of a monobasic acid molecule are part of a monobasic acid molecule of C ₅ , and (a-3) an acid that is part of an iC ₅ acid. At least about 85% of the carboxyl groups in the acid mixture, wherein% of the carboxyl groups in the mixture are part of the dibasic acid molecule, or (b) up to about 7% of the carboxyl groups in the acid mixture (b-1) are part of the dibasic acid, and (b- 2) at least about 88% of the carboxyl groups in the acid mixture are part of a monobasic acid having at least C ₉ and at least one branched chain, and (b-3) at least about 84% of the total carboxyl groups in the acid mixture are part of the trimethylhexanoic acid molecule; Wherein at least about 60% of the carboxyl groups in the acid mixture are part of 3,5,5-trimethyl hexanoic acid molecules Prepared by reacting with a mixture of acid molecules satisfying The method of claim 3, A mixture of alcohol molecules of type 1 (i) wherein at least about 89% of the molecules in total are TMP or PE, and (ii) at least about 92% of the molecules are selected from the group of acids containing C ₅ per molecule and such C ₅ acid molecules At least about 84% of is prepared by reacting with an acid mixture that is pentanic acid; A mixture of alcohol molecules of type 2 wherein (i) at least about 85% of the molecules are PE molecules, and (ii) at least about 90% of the acid molecules each containing up to C ₁₀ , (a) in the mixture At least about 21% of the acid molecules are iC ₅ , (c) less than about 49% of the acid molecules in the mixture containing at least 9 carbon atoms, branched or unbranched, and (d) the total in the mixture (d-1). At least about 41% of the acid molecules are of one kind of trimethylhexanoic acid, and up to about 1% of the molecules in the acid mixture have at least one carboxyl group, or (d-2) at least 10% of the carboxyl groups in the acid mixture are C ₅ to C ₇ Is part of a dibasic acid molecule of which is prepared by reacting an acid molecule mixture in which at least about 96% of the monobasic acid molecules in the acid mixture meet conditions having 5 or 6 carbon atoms; A mixture of alcohol molecules in which type 3 is (i) at least about 90% PE or DPE molecules and at least about 80% of them are PE molecules, (ii) as a mixture of acid molecules, (a) (a-1) the acid mixture is at least about 29% of the carboxyl group in the C ₅ to C ₇ are part of dibasic acid molecules, (a-2) a monobasic acid is part acid mixture of about 95% or more carboxyl groups in the molecule acid monobasic the C ₅ molecule (A-3)% of the carboxyl groups in the acid mixture that is part of the iC ₅ acid is at least about 108% of the% carboxyl groups in the acid mixture that is part of the dibasic acid molecule, or (b) (b-1) about 3 in the acid mixture Up to% carboxyl groups are part of the dibasic acid, (b-2) at least about 92% of the carboxyl groups in the acid mixture are part of monobasic acids having at least C ₉ and at least one branched chain, and (b-3) in the acid mixture At least about 88% of the total carboxyl groups are part of the trimethylhexanoic acid molecule, and at least about 71% of the carboxyl groups in the acid mixture A composition prepared by reacting with an acid molecule acid mixture that meets conditions that are part of a 3,5,5-trimethyl hexanoic acid molecule. The method of claim 4, wherein Type 1 is (i) about 95% or more molecules are TMP or PE the alcohol molecule mixture, (ii) and is at least about 97% of molecules selected from the acid group containing a C ₅ per molecule, these C ₅ acid molecule At least about 93% is prepared by reacting with an acid mixture that is pentanic acid; A mixture of alcohol molecules in which type 2 is (i) at least about 90% of the molecules are PE molecules, and (ii) at least about 95% of the acid molecules each contain C ₁₀ or less, and (a) in the mixture At least about 28% of the acid molecules are iC ₅ and (b) the ratio of the percentage of acid molecules in the unbranched and C ₈ or more mixture to% of the acid molecules in the branched and C ₅ or less mixture is about 1.21 or less and (c) The percentage of acid molecules in the mixture containing 9 or more carbon atoms, branched or unbranched, is less than about 49%, and (d) (d-1) more than about 41% of all the acid molecules in the mixture are one type of trimethylhexanoic acid. Up to about 1% of the molecules in the acid mixture have at least one carboxyl group, or (d-2) at least about 14% of the carboxyl groups in the acid mixture are part of the dibasic acid molecule, and at least about 96% of the monobasic molecules in the acid mixture. Is a mixture of acid molecules that satisfy the condition By been manufactured; A mixture of alcohol molecules in which type 3 is (i) at least about 95% PE or DPE molecules and at least about 85% of them are PE molecules, (ii) as a mixture of acid molecules, (a) (a-1) At least about 33% of the carboxyl groups in the acid mixture are part of a dibasic acid molecule, and (a-2) at least about 98% of the carboxyl groups in the acid mixture that is part of a monobasic acid molecule are part of a monobasic acid molecule of C ₅ , and (a- 3)% of the carboxyl group in the acid mixture which is part of the iC ₅ acid is at least about 130% of the% carboxyl group in the acid mixture which is part of the dibasic acid molecule, or (b) up to about 1% of the carboxyl group in the acid mixture (b-1) Part of a base acid, (b-2) at least about 96% of the carboxyl groups in the acid mixture are part of a monobasic acid having at least C ₉ and at least one branched chain, and (b-3) at least about 92% of the total carboxyl groups in the acid mixture Is part of the trimethylhexanoic acid molecule, and at least about 84% of the carboxyl groups in the acid mixture are 3,5,5-trimethyl Characterized in that the composition of the mixture prepared by the reaction of the acid molecule that meets one or more conditions of the condition part of Shanshan molecule. At least about 95% by weight of the composition according to claim 5 and the remaining weight% of antioxidants, heat stability improvers, corrosion inhibitors, metal deactivators, lubricity additives, viscosity improvers, pour point and flocculation point depressants, detergents, dispersants, antifoaming agents A lubricant comprising at least one additive selected from the group consisting of abrasion resistant and high pressure resistant additives. At least about 92% by weight of the composition according to claim 3 and the remaining weight% of antioxidants, thermal stability improvers, corrosion inhibitors, metal deactivators, lubricity additives, viscosity improvers, pour point and flocculation point depressants, detergents, dispersants, antifoaming agents A lubricant comprising at least one additive selected from the group consisting of abrasion resistant and high pressure resistant additives. At least about 92% by weight of the composition according to claim 2 and the remaining weight% of antioxidants, heat stability improvers, corrosion inhibitors, metal deactivators, lubricity additives, viscosity improvers, pour point and flocculation point depressants, detergents, dispersants, antifoaming agents A lubricant comprising at least one additive selected from the group consisting of abrasion resistant and high pressure resistant additives. At least about 92% by weight of the composition according to claim 1 and the remaining weight% of antioxidants, thermal stability improvers, corrosion inhibitors, metal deactivators, lubricity additives, viscosity improvers, pour point and flocculation point depressants, detergents, dispersants, antifoaming agents Lubricants comprising at least one additive selected from the group consisting of abrasion resistant and high pressure resistant additives 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling fluid consisting essentially of the lubricant according to claim 9. 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling working fluid consisting essentially of the lubricant according to claim 8. 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling fluid consisting essentially of the lubricant according to claim 7. A cooling fluid comprising at least 85% by weight of 1,1,1,2-tetrafluoroethane and the remaining weight% of the lubricant according to claim 6. 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling fluid consisting essentially of the lubricant according to claim 5. 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling fluid consisting essentially of the lubricant according to claim 4. 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling fluid consisting essentially of the lubricant according to claim 3. 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling fluid consisting essentially of the lubricant according to claim 2. 85% by weight or more of a primary heat transfer fluid selected from the group consisting of pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof Cooling working fluid consisting essentially of the lubricant according to claim 1. Operating the cooler, including circulating compression, liquefaction, expansion, and evaporation of a heat transfer fluid comprising at least 85 wt.% Of 1,1,1,2-tetrafluoroethane and the remaining wt. Way. At least 85% by weight of a primary heat transfer fluid selected from pentafluoroethane, 1,1-difluoroethane, 1,1,1-trifluoroethane, tetrafluoroethane, and mixtures thereof, and the remaining weight percent A method of operating a cooler, including circulating compression, liquefaction, expansion and evaporation of a heat transfer fluid comprising a lubricant according to claim 1.