ES2708768T3 - Use of an aliphatic polyether - Google Patents

Abstract

Use of an aliphatic polyether selected from poly (alkylene oxide) homopolymers having the formula ** Formula ** wherein R and R2 are independently selected from hydrocarbyl groups having from one to four carbon and hydrogen atoms, with the exception that at least one of R and R2 is a hydrocarbyl group; R1 is an aliphatic hydrocarbylene group having 3 to 6 carbon atoms, and n is an integer from 4 to 50, where the polyether has a number average molecular weight of 300 to 3000, to dissolve oxidation or varnish products in a hydrocarbon-based lubricant containing oxidation or varnish products, particularly a hydrocarbon-based oil, increasing the polarity of the hydrocarbon-based lubricant to allow the hydrocarbon-based lubricant to dissolve the oxidation products or varnish particles, where the polyether it is added in such an amount that the lubricant comprises from 2% by weight to 20% by weight of the polyether.

Description

DESCRIPTION

Use of an aliphatic polyether

Field of the invention

The present invention is useful in the field of hydrocarbon-based lubricants.

Introduction to the description

This section provides useful information for understanding the invention, but it is not necessarily prior art. Hydrocarbon-based lubricants, such as hydrocarbon-based oils, are susceptible to oxidation and varnish formation during high temperature applications. Over the years, the oil industry has eliminated some of the impurities in crude oil through hydrocracking or has produced synthetic hydrocarbons to minimize subsequent oxidation problems. In another measure taken to address the problem, nitrogen has been used to create an insulating layer in the tank to prevent an oil based on hydrocarbons from coming into contact with oxygen. More recently, the companies have developed methods of testing the formation of varnish and filters for the elimination of varnish to separate the soluble varnish by filtration. Despite such efforts, after a period of time in use it is still necessary to remove the used oil that has been filled with sludge and varnish and recharge the system with new oil. In addition, varnish deposits on the parts of the machine can cause the pieces to stick and interfere with the operation of the machine.

Both the drainage and the filling of a lubrication system and the use of a filtration system to separate the varnish are expensive options and can not guarantee that the varnish will not be deposited on the parts of the machine in operation. Although progress has been made in decelerating the oxidation process, the prediction of varnish formation and the separation of part of the varnish by filtration, the varnish can only be separated by filtration if the oil returns to the filter. The oil in the lines of a lubrication system can continue degrading and depositing varnish, causing problems with the operation of the machinery. The dispersants can help keep the soft varnish particles suspended in a hydrocarbon-based lubricant, but the dispersing micelles formed increase the viscosity of the lubricant and affect the performance of the lubricant. Martin Greaves, et al. describe oil-soluble base oils (Lubrication Science 2012; 24: 251-262).

Compendium of the description

The invention is set forth in the set of appended claims.

Methods are described in which an aliphatic polyether, selected from: poly (alkylene oxides) with monomeric units having 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms, more preferably 3 or 4 carbon atoms, and more preferably 3 carbon atoms, is added to hydrocarbon-based lubricants, particularly hydrocarbon-based oils; such methods in which the hydrocarbon-based lubricant, particularly a hydrocarbon-based oil, comprises oxidation products that are dissolved by the addition of the aliphatic polyether; hydrocarbon-based lubricant, particularly a hydrocarbon-based oil, containing an aliphatic polyether selected from: poly (alkylene oxides) with monomeric units having 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms, more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms; lubrication systems that include these lubricants based on hydrocarbons or oils based on hydrocarbons; machines that include these lubrication systems; and methods of operation of the machines that include these lubrication systems.

In various embodiments thereof, the aliphatic polyether is selected from aliphatic polyethers having the formula

wherein R and R2 are independently selected from aliphatic hydrocarbyl groups having from one to four carbon and hydrogen atoms, with the warning that at least one of R and R2 is a hydrocarbyl group; R1 is an aliphatic hydrocarbylene group having from 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms, more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms; and n is an integer from 4 to 50.

The polyether has a number average molecular weight of 300 to 3000, determined by gel permeation chromatography using polystyrene standards. The polyether can be added to the hydrocarbon-based lubricant or the hydrocarbon-based oil or it can be included in a hydrocarbon-based lubricant or hydrocarbon-based oil in an amount of 2% by weight to 20% by weight of the polyether, preferably 5% by weight. Weight% to 20% by weight of the polyether, based on the total weight of the lubricant.

In the practice of the invention, a lubricant or oil based on hydrocarbons containing oxidation products or varnish is treated by adding to the lubricant or oil an aliphatic polyether selected from poly (alkylene oxide) homopo-polymers having the formula

wherein R and R2 are independently selected from aliphatic hydrocarbyl groups having from one to four carbon and hydrogen atoms, with the warning that at least one of R and R2 is a hydrocarbyl group; R1 is an aliphatic hydrocarbylene group having from 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms, more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms; and n is an integer from 4 to 50.

The polyether has a number average molecular weight of 300 to 3000, determined by gel permeation chromatography using polystyrene standards. The hydrocarbon-based lubricant or the hydrocarbon-based oil containing oxidation or varnish products can be treated with 2% by weight to 20% by weight of the polyether, preferably 5% by weight to 20% by weight of the polyether, based on the total weight of lubricant treated. In various embodiments, hydrocarbon-based lubricants, particularly hydrocarbon-based oils, which contain a polyether are used in lubrication systems in which the lubricant or oil reaches temperatures above about 100 ° C, or in which the lubricant or Oil based on hydrocarbons is subject to oxidizing conditions.

Lubricants, particularly hydrocarbon-based oils, can be used in lubrication systems for turbines, hydraulic systems, hydrostatic transmissions, in hydraulic systems of mobile equipment and in other similar machines where the cleaning of the oil lubricant is a problem.

The lubricant compositions and methods described minimize or prevent the formation of varnish and prolong the life of the hydrocarbon-based oil used in applications where during use they are exposed to high temperatures or oxidizing conditions. In one method, the lubricant is a hydrocarbon-based oil used to lubricate a power generation turbine. The lubricant dissolves the products (pre-varnish) of oxidation of the lubricant and reduces the insolubles in pentane. This prevents the accumulation of varnish on lubricated surfaces, such as the surfaces of turbine systems, which can cause sticky valves and shots from the turbines of the power generator.

While not wishing to be bound by any theory, it is believed that poly (alkylene oxide) homopolymers or poly (vinyl ethers) do not behave as dispersants of the oxidation products and the varnish particles, but increase the polarity of the base oil based on hydrocarbons to allow the oil based on hydrocarbons to dissolve the oxidation products and the varnish particles. The dissolved oxidation products do not agglomerate.

The lubricating compositions and methods described revitalize used oils (reduced VPR index) so they do not have to be drained or refilled, which saves on waste disposal, eliminates the need to buy expensive filtration systems to separate the varnish and avoids or it diminishes the future formation of varnish to extend the life of the oil.

"A", "the", "at least one" and "one or more" are used interchangeably to indicate that at least one of the elements is present; a plurality of such articles may be present, unless the context clearly indicates otherwise.

Other areas of applicability will become apparent from the description provided herein. It is to be understood that the description and the specific examples are intended only for purposes of illustration and are not intended to limit the scope of the present disclosure.

Detailed description

In the following, a detailed description of examples of non-limiting embodiments is provided.

In these methods and compositions a lubricating base oil based on hydrocarbons is used. Base oils based on hydrocarbons can be manufactured using a variety of different processes including, but not limited to, distillation, solvent refining, hydrogen processing, oligomerization, esterification and re-refining. Non-limiting examples of hydrocarbon-based base oils are oils based on aliphatic hydrocarbons, oils based on hydrocracked and highly hydrotreated hydrocarbons, paraffinic oil refined with furfural, naphthenic oil refined with solvents and aromatic oil refined with solvents; synthetic hydrocarbon oils, such as poly (alpha-olefin) oils such as hydrogenated or partially hydrogenated olefins including hydrogenated hexene oligomers, hydrogenated octene oligomers, hydrogenated decene oligomers, hydrogenated C ^6-10 oligomers and C ^8- oligomers ¹⁰ hydrogenated; mineral oils such as liquid petroleum oils and mineral lubricating oils treated with solvents or treated with acid from the paraffinic, naphtenic or mixed paraffinic-naphthenic types such as 100 "neutral paraffinics, and oils derived from coal or schist; alkylbenzenes such as dodecylbenzenes, tetradecylbenzenes, dinonylbenzenes, di- (2-ethylhexyl) -benzenes; polyphenyls such as biphenyls, terphenyls, alkylated polyphenyls, alkylated diphenyl ethers and mixtures thereof.

The hydrocarbon-based lubricant containing a polyether can be manufactured using a hydrocarbon-based oil-based base oil or a fully formulated hydrocarbon-based lubricant, particularly a fully-formulated hydrocarbon-based oil made from a used hydrocarbon-based oil or lubricant containing oxidation products, such as varnish particles or soft bodies, which may also include one or more lubricating additives.

The base oil or base lubricant is combined with a polyether selected from poly (alkylene oxide) homopolymers.

Poly (alkylene oxide) homopolymers have the formula

wherein R and R2 are independently selected from aliphatic hydrocarbyl groups having from one to four carbon and hydrogen atoms, with the warning that at least one of R and R2 is a hydrocarbyl group; R1 is an aliphatic hydrocarbylene group having from 3 to 6 carbon atoms, preferably 3 to 5 carbon atoms, more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms; and n is an integer from 4 to 50, preferably from about 10 or from about 15 to about 25 or about 30 or about 35 or about 40, especially preferably from about 10 to about 40 or from about 10 to about 35 or about 15 to about 35. The poly (alkylene oxide) homopolymer has a number average molecular weight of at least 300. The poly (alkylene oxide) homopolymer has a number average molecular weight of up to 3000, more preferably up to about 2000, and particularly preferably from about 500 to about 1200. The number average molecular weight is determined by gel permeation chromatography using polystyrene standards.

Non-limiting examples include poly (propylene oxide) and poly (butylene oxide) optionally having a hydroxyl terminal group and an alkoxy end group or, if there is no hydroxyl terminal group, two terminal alkoxy groups, where the alkoxide end groups may be methoxide, ethoxide, propoxide, isopropoxide, n-butoxide, isobutoxide, sec-butoxide and tert-butoxide end groups. Said poly (alkylene oxide) polymers can be prepared using an alcohol as initiator molecule by anionic polymerization of an alkylene oxide with basic catalysts, e.g. eg, alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, sodium or sodium metal methoxide, or by cationic polymerization of an alkylene oxide with acidic catalysts such as aluminum chloride, antimony pentachloride, boron trifluoride, chloride of iron (III) or tin (IV) chloride. Many poly (alkylene oxides) terminated in alkoxide are commercially available, for example, in BASF under the tradename PLURASAFE® and in Dow Chemical under the tradename UCON ™.

In various embodiments, the hydrocarbon-based oil containing a polyether or other lubricant that is prepared by combining the oil based on hydrocarbons or another hydrocarbon-based lubricant and a polyether can contain from 2 wt% to 20 wt% of the polyether, preferably from 5% by weight to 20% by weight of the polyether, based on the total weight of the hydrocarbon-based lubricant containing a polyether.

The polyether is not amphiphilic to form micelles as a surfactant did. Rather, it is understood that the polyether changes the characteristics of the lubricant to allow the oxidation products and the varnish particles to dissolve in the oil or in another hydrocarbon-based lubricant.

The oil based on hydrocarbons or another based on hydrocarbons is preferably free of detergents, surfactants and dispersants. The oil or lubricant may include one or more additives other than detergents, surfactants and dispersants. Non-limiting examples of suitable additives include antioxidants, antiwear agents, extreme pressure agents, friction reducing agents, metal deactivating agents such as benzotriazoles, viscosity modifiers, pour point depressants, stabilizers, corrosion inhibitors and suppressants. of flammability. Such additives may be used alone or in any combination of two or more. There are no particular restrictions on the inclusion of such additives. In general, additives such as these can be present in less than or equal to about 10% by weight of the lubricant composition. Various embodiments of the lubricant composition may include from about 0.1 to about 5% by weight of an additive or a combination of additives or from about 0.2 to about 2% by weight of an additive or a combination of additives.

Non-limiting examples of the antioxidants that may be used include phenolic antioxidants such as 2,6-di-t-butyl-4-methylphenol and 4,4'-methylenebis (2,6-di-t-butylphenol) and bisphenol A; amine and thiazine type antioxidants such as p, p-dioctylphenylamine, monooctyldiphenylamine, phenothiazine, 3,7-dioctylphenothiazine, N, N-di (2-naphthyl) -p-phenylenediamine, phenyl-1-naphthylamine, phenyl-2-naphthylamine, alkylphenyl-1-naphthylamines and alkylphenyl-2-naphthylamines; and sulfur-containing antioxidants, such as alkyl disulfide, thiodipropionic acid esters and benzothiazole. The lubricant composition may comprise up to about 5.0% by weight of antioxidants, about 0.1 to about 5% by weight, about 0.1 to about 2.0% by weight, or about 0.2 to about 0.8 % in weight of antioxidants. The lubricating compositions may include one or a combination of two or more antioxidant compounds.

In certain embodiments, the hydrocarbon-based lubricant and the hydrocarbon-based oil compositions may include one or more extreme pressure or anti-wear additives. Non-limiting examples of suitable antiwear / extreme pressure additives include types containing sulfur and phosphorus, such as esters of phosphoric acid, acid esters of phosphoric acid, phosphates of branched alkylamines containing from 5 to 20 carbon atoms, esters of thiophosphoric acid, amine salts of acid esters of phosphoric acid, and chlorinated esters of phosphoric acid and esters of phosphorous acid which are esters of phosphoric acid or of phosphorous acid with alkanols or polyether alcohols. Specific, non-limiting examples of esters of phosphoric acid include tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triumphyl phosphate, tridodecyl phosphate, tritridecyl phosphate. , tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixilenyl phosphate, cresyltyphenyl phosphate and xylenyl diphenyl phosphate. Specific, non-limiting examples of acid esters of phosphoric acid which may be mentioned are monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate , monoundecyl acid phosphate, monododecyl acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monoolefin acid phosphate, dibutyl acid phosphate , dipentyl acid phosphate, dihexyl acid phosphate, dihexyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate, ditetradecyl acid phosphate , dipentadecyl acid phosphate, dihexadecyl acid phosphate, diheptadecyl acid phosphate , dioctadecyl acid phosphate and dioleflo acid phosphate. Specific non-limiting examples of thiophosphoric acid esters include tributyl phosphorothionate, tripentyl phosphorothionate, trihexyl phosphorothionate, triheptyl phosphorothionate, trioctyl phosphorothionate, trinonyl phosphorothionate, tridecyl phosphorothionate, triumphyl phosphorothionate, tridodecyl phosphorothionate, tritridecyl phosphorothionate, tritetradecyl phosphorothionate, tripentadecyl phosphorothionate, trihexadecyl phosphorothionate, triheptadecyl phosphorothionate, trioctadecyl phosphorothionate, trioleflo phosphorothionate, triphenyl phosphorothionate, tricresyl phosphorothionate, trixilenyl phosphorothionate, cresylidiphenyl phosphorothionate and xylenyl diphenyl phosphorothionate. Specific, non-limiting examples of salts of amines of acid esters of phosphoric acid include salts of acid esters of phosphoric acid with amines such as methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, trihepilamine and trioctylamine. Specific non-limiting examples of chlorinated esters of phosphoric acid include tris (dichloropropyl) phosphate, tris (chloroethyl) phosphate, tris (chlorophenyl) phosphate and poly (alkylene oxide) phosphate and bis [di (chloroalkyl)]. As esters of phosphorous acid there may be mentioned dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleflophosphite, diphenyl phosphite. , dicresyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triumphyl phosphite, tridodecyl phosphite, trioleflo phosphite, triphenyl phosphite and phosphite of tricresyl. The extreme pressure / anti-wear additives can be used individually or in any combination, in any desired quantity. In various embodiments, the lubricant or oil composition may include from about 0.01 wt% to about 5.0 wt%, about 0.01 wt% to about 4.0 wt%, about 0.02 wt% in weight to about 3.0% by weight, or 0.1% by weight to about 5.0% by weight of each of the extreme pressure additives and antiwear additives. These additives can be used alone or in any combination.

In various embodiments, the hydrocarbon-based lubricant or the hydrocarbon-based oil may include one or more corrosion inhibitors, such as those selected from isomer mixtures of N, N-bis (2-ethylhexyl) -4-methyl-1H- benzotriazol-1-methylamine and N, N-bis (2-ethylhexyl) -5-methyl-1H-benzotriazol-1-methylamine. The hydrocarbon-based lubricant or the hydrocarbon-based oil may include from about 0.01 to about 1.0% by weight of one or more corrosion inhibitors, from about 0.01 to about 0.5% by weight of one or more. more corrosion inhibitors, or from about 0.05 to about 0.15% by weight of one or more corrosion inhibitors.

Viscosity modifiers (or viscosity index improvers) are polymeric materials, typical examples of which are polyolefins, such as ethylene-propylene copolymers, hydrogenated styrene-isoprene block copolymers, hydrogenated styrene-butadiene copolymers, ethylene copolymers and propylene, acrylic polymers produced by polymerization of acrylate and methacrylate esters, hydrogenated isoprene polymers, polyalkyl styrenes, hydrogenated copolymers of conjugated diene and alkenyl arene, polyolefins, esters of copolymers of maleic anhydride-styrene and polyisobutylene.

Non-limiting examples of pour point depressants include poly (alkyl methacrylates), poly (acrylates), alkyl), poly (vinyl acetate), polyalkylstylenes, polybutene, chlorinated paraffin condensates and naphthalene, and condensates of chlorinated paraffin and phenol.

Non-limiting examples of flammability suppressants include trifluorochloromethane, trifluoroiodomethane, phosphate esters and other phosphorus compounds, and hydrocarbons, hydrofluorocarbons or fluorocarbons containing iodine or bromine.

A hydrocarbon-based lubricant or hydrocarbon-based oil can be treated by adding to the lubricant or oil a polyether selected from poly (alkylene oxide) homopolymers as described. The hydrocarbon-based lubricant or the hydrocarbon-based oil being treated contains an oxidation product, e.g. eg, varnish or pre-varnish type oxidation products, and the polyether is added in an amount sufficient to cause the oxidation products to dissolve in the lubricant. In various embodiments, the polyether is added in an amount such that the lubricant or the oil comprises from 2 wt% to 20 wt% or from 5 wt% to 20 wt% of the polyether. In various embodiments, the viscosity of a hydrocarbon-based oil or other lubricant containing varnish, pre-varnish, or other oxidation products is reduced by the addition of the polyether to a degree greater than that expected based on a weighted average of the viscosity of the oil or lubricant based on hydrocarbons and the viscosity of the polyether.

A hydrocarbon-based lubricant or a hydrocarbon-based oil treatment composition for treating hydrocarbon-based lubricant or hydrocarbon-based oil containing varnish or other oxidation products includes the polyether that has been described and at least one additive that does not be a detergent, surfactant and dispersant. In various embodiments, the additive is selected from antioxidants, antiwear agents, extreme pressure agents, friction reducing agents, metal deactivating agents such as benzotriazoles, viscosity modifiers, pour point depressants, stabilizers, corrosion inhibitors. , flammability suppressors and combinations. of these. In particular embodiments, the treatment composition based on a lubricant or oil comprises the polyether and an antioxidant. The lubricant or the oil treatment composition reduces the viscosity of a hydrocarbon based lubricant or hydrocarbon based oil containing varnish, pre-varnish or other oxidation products to a degree greater than expected based on a weighted average of the viscosity of the lubricant based on hydrocarbons or oil based on hydrocarbons and the viscosity of the polyether treatment composition.

The oxidation products dissolve and do not agglomerate in the hydrocarbon-based lubricant or in the hydrocarbon-based oil contained in the polyether. This is demonstrated in the following examples where the Varnish Potential test shows that the condemned "used" oil has returned to good operating conditions. The viscosity of the hydrocarbon-based oil used decreases, the ISO cleaning codes decrease, the pentane insolubles decrease, the lubrication properties increase and the VPR (varnish potential index) is reduced to "as new fluid" acceptable for its use .

Examples

Example 1. Remediation of a used turbine oil

A sample of turbine oil used Chevron GST-32 was extracted from a system that had experienced system failures and varnish formation problems. The parameters of the used oil were measured according to the following published test methods.

Insoluble VP in pentane - ASTM D 893

Classification of sediments by ultracentrifuge - Metodo Mobil 1169

Colorimetric filter patch - ASTM W K 27308

Ruler (from the English "Remaining Useful Life Evaluation Routine": Routine evaluation of the remaining useful life),% -ASTM D 6971

Classification of the varnish potential - ASTM D 4378

Viscosity (SUS) - ASTM D 445

Total acidity index - ASTM D 664

Water content - ASTM E 203

Particle count - ISO 4406.

The measured values of the turbine oil used Chevron GST-32 as it was when it was removed from the system are shown in Table 1. The parameters of a new unused sample of Chevron GST-32 turbine oil were also measured and shown in Table 1.

A portion of 90 parts by weight of the used turbine oil Chevron GST-32 was combined with 10 parts by weight of poly (propylene oxide), terminated with a butyl ether group and a hydroxyl group, with a number average molecular weight. of 1000 and with a content of 0.6% by weight of the butylated reaction product of p-cresol and dicyclopentadiene (CAS No. 68610-51-5) and 0.01% by weight of Cobratec 122 (available from PMC Specialties Group Inc., Cincinnati, OH) to make a turbine remediated oil. The parameters of this remediated Chevron GST-32 turbine oil were measured and are shown in Table 1.

The theoretical values of the parameters were determined for a combination of 90 parts by weight of the turbine oil used Chevron GST-32 combined with 10 parts by weight of the poly (propylene oxide) taking a weighted average of the values of the individual fluids. The theoretical values represent the values of the properties of the oil that are expected if the polyether had no effect on the varnish particles contained in the turbine oil used Chevron GST-32. These values are also shown in Table1. The difference between the values of the theoretical parameters and the values actually obtained by combining the turbine oil used with the poly (propylene oxide) show that the added poly (propylene oxide) removed the soft varnish particles from the turbine oil used.

The turbine oil used Chevron GST-32 remediated with 10% by weight of poly (propylene oxide) had a 75% elimination of the insolubles in pentane, a classification of sediments by ultracentrifuge equivalent to new oil and a reduction in bodies of measured color. The Ruler test results show a 10% increase over the expected value of antioxidant content of the original antioxidant in Chevron GST-32, which differs from the antioxidant that was combined with the added polypropylene to remediate the used oil. A drop of 10 SUS units in the viscosity for the remediated oil is also evidence that the soft partroulas of the varnish have dissolved in the oil. When the varnish breaks poly (propylene oxide) also releases other polar molecules, such as water.

Example 2. Remediation of a used turbine oil

A sample was taken from the used turbine oil Mobil SHC-824 from a system that finishes an excess of varnish. The parameters of the used oil were measured and given in Table 2. A portion of 90 parts by weight of the used turbine oil Mobil SHC-824 was combined with 10 parts by weight of poly (propylene oxide), finished with a group. butyl ether and a hydroxyl group, with a number average molecular weight of 1000 and with a content of 0.6% by weight of the butylated reaction product of p-cresol and dicyclopentadiene (CAS No. 68610-51-5) and 0.01% by weight of Cobratec 122 (available from PMC Specialties Group Inc., Cincinnati, OH) to make a remediated turbine oil. The parameters of this Mobil SHC-824 remediated turbine oil were measured and shown in the Table 2. Finally, the theoretical values of the replacement of the lubricant system with new turbine oil Mobil SHC-824 are also shown in Table 2.

The addition of poly (propylene oxide) reduced the viscosity of the turbine oil by 3 cSt (10 SUS) below a theoretical value. This demonstrates that the addition of the poly (propylene oxide) significantly reduced the effective molecular weight of the lubricant by reducing the agglomeration of polar bodies that had formed soft particles of varnish in the used oil. A reduction in the total acidity index shows that the equilibrium between the active amine and phenolic antioxidants in the turbine fluid used has been restored. The reduction of the particle count for the reused used oil shows that the added poly (propylene oxide) removed the varnish particles from the used turbine oil when dissolved.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It does not pretend to be exhaustive or limit the invention.

Claims (3)

1. Use of an aMphatic polyether selected from poly (alkylene oxide) homopo-polymers having the formula

wherein R and R2 are independently selected from hydrocarbyl groups having one to four carbon and hydrogen atoms, with the proviso that at least one of R and R2 is a hydrocarbyl group; R1 is an aliphatic hydrocarbylene group having from 3 to 6 carbon atoms, and n is an integer from 4 to 50, wherein the polyether has a number average molecular weight of from 300 to 3000, to dissolve oxidation products or varnish in a hydrocarbon-based lubricant containing oxidation or varnish products, particularly a hydrocarbon-based oil, increasing the polarity of the hydrocarbon-based lubricant to allow the hydrocarbon-based lubricant to dissolve the oxidation products or the varnish particles, where the polyether it is added in an amount such that the lubricant comprises from 2% by weight to 20% by weight of the polyether. 2. The use according to claim 1, wherein the poly (alkylene oxide) homopolymer comprises a butoxide-terminated poly (propylene oxide). 3. The use according to claim 1 or 2, wherein the polyether is added in an amount such that the lubricant comprises from 5% by weight to 20% by weight of the polyether.