US20070021311A1 - Aviation phosphate ester functional fluids with enhanced acid scavenging properties - Google Patents
Aviation phosphate ester functional fluids with enhanced acid scavenging properties Download PDFInfo
- Publication number
- US20070021311A1 US20070021311A1 US11/484,206 US48420606A US2007021311A1 US 20070021311 A1 US20070021311 A1 US 20070021311A1 US 48420606 A US48420606 A US 48420606A US 2007021311 A1 US2007021311 A1 US 2007021311A1
- Authority
- US
- United States
- Prior art keywords
- fluid
- phosphate
- alkyl
- acid
- carbon atoms
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- KGYOADYRSROVBA-UHFFFAOYSA-N CC(=O)C1(C)CC2OC2CC1(C)C Chemical compound CC(=O)C1(C)CC2OC2CC1(C)C KGYOADYRSROVBA-UHFFFAOYSA-N 0.000 description 3
- 0 *OC(C1CC2OC2CC1)=O Chemical compound *OC(C1CC2OC2CC1)=O 0.000 description 1
- UHFSSPJEBCZDFN-UHFFFAOYSA-N CC(=O)C1CCC2OC2C1.O.O=C(O)C1CCC2OC2C1 Chemical compound CC(=O)C1CCC2OC2C1.O.O=C(O)C1CCC2OC2C1 UHFSSPJEBCZDFN-UHFFFAOYSA-N 0.000 description 1
- LRMLWYXJORUTBG-UHFFFAOYSA-N CP(C)(C)=O Chemical compound CP(C)(C)=O LRMLWYXJORUTBG-UHFFFAOYSA-N 0.000 description 1
- OXQXGKNECHBVMO-UHFFFAOYSA-N OC(C1CC2OC2CC1)=O Chemical compound OC(C1CC2OC2CC1)=O OXQXGKNECHBVMO-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
- C10M169/04—Mixtures of base-materials and additives
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
- C10M2207/10—Carboxylix acids; Neutral salts thereof
- C10M2207/24—Epoxidised acids; Ester derivatives thereof
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2215/00—Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
- C10M2215/086—Imides
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
- C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
- C10M2223/04—Phosphate esters
- C10M2223/0405—Phosphate esters used as base material
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
- C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
- C10M2223/04—Phosphate esters
- C10M2223/041—Triaryl phosphates
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2223/00—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions
- C10M2223/02—Organic non-macromolecular compounds containing phosphorus as ingredients in lubricant compositions having no phosphorus-to-carbon bonds
- C10M2223/04—Phosphate esters
- C10M2223/041—Triaryl phosphates
- C10M2223/0415—Triaryl phosphates used as base material
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
- C10N2030/66—Hydrolytic stability
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/08—Hydraulic fluids, e.g. brake-fluids
Definitions
- the present invention relates to aviation phosphate ester functional fluids resistant to acid build-up.
- Phosphate ester based functional fluids are well known in the lubrication art and have been utilized for years as electronic coolants, power transmission and hydraulic fluids and refrigeration equipment fluids to mention a few. Hydraulic fluids which are to be used in aircraft applications must meet certain performance criteria among which are thermal stability, fire resistance, low susceptibility to viscosity changes over a wide range of temperatures, hydrolytic stability and good lubricity.
- phosphate esters are the most commonly used base stocks of which tributyl phosphate, isopropylated triphenyl phosphates, n-butyl diphenyl phosphate, and di-n-butyl phenyl phosphate are widely used components.
- Phosphate ester based functional fluids useful as aircraft hydraulic fluids have been described in U.S. Pat. Nos. 5,464,551, 3,723,320 and 3,679,587.
- phosphate esters because of the superior fire resistance properties of phosphate esters.
- the reduced fire risk is accompanied by a debit in various performance parameters such as lesser stability when compared to the hydrocarbon based fluids or silicate ester fluids also in use.
- Phosphate esters tend to absorb atmospheric moisture readily and build up high concentrations of water (0.3 to 1% water, sometimes more). Like all esters, these fluids have the potential to hydrolyze (react with water to form alcohols and acids). The presence of high concentrations of water typically results in extent of hydrolysis setting the life of the fluid (point at which the fluid has to be replaced).
- the OEMs Acid Number specification limit for in-service fluids has been set at 1.5 mg KOH/g.
- U.S. Pat. No 5,464,551 describes a base stock comprising between about 10 to 100 wt % of a trialkyl phosphate, between about 0 and 70 wt % dialkyl aryl phosphate and from about 0 to 25 wt % alkyl diaryl phosphate, the sum of the proportionate amount of each component equally 100%.
- the alkyl substitutent of the trialkyl phosphate contains between 3 and 8 carbons, preferably between 4 and 8 carbons, more preferably between 4 and 5 carbons and are bonded to the phosphate moiety via a primary carbon.
- the alkyl substitutents of the tri alkyl phosphate, the di alkyl aryl phosphate and the alkyl di aryl phosphate are isoalkyl groups, substantially iso C 4 and iso C 5 alkyl groups.
- WO 96/17517 Another advance in base fluid is described in WO 96/17517, published Jun. 13, 1996, which teaches a phosphate ester base stock comprising 60 to 95 wt % of a tri alkyl phosphate and about 5 to 40 wt % of a second component selected from the group consisting of triaryl phosphate, a mixture of triaryl phosphate and linear polyoxy alkylene material, and a linear polyoxyl alkylene material, which base stock is free of di alkyl aryl phosphate and alkyl di aryl phosphate.
- a phosphate ester base stock comprising 60 to 95 wt % of a tri alkyl phosphate and about 5 to 40 wt % of a second component selected from the group consisting of triaryl phosphate, a mixture of triaryl phosphate and linear polyoxy alkylene material, and a linear polyoxyl alkylene material, which base stock is free of di alkyl aryl
- the alkyl groups are, aliphatic and alicyclic group wherein the aliphates group are straight or branched chain, and contain independently, 1 to 12 carbon atoms and di aryl groups are, independently, phenyl or alkyl substituted phenyl having from 7 to 20 carbon atoms.
- Phosphate ester functional fluids are formulated with an acid scavenger to prevent acid build-up.
- U.S. Pat. Nos. 3,723,320, 3,941,708 and 5,464,551 disclose epoxide acid scavengers for use in phosphate ester based functional fluids and teach that the preferred epoxides are 3,4-epoxycycloalkyl carboxylates.
- alkyl epoxides including the 3,4-epoxycycloalkyl carboxylate acid scavengers currently used in commercial phosphate ester based functional fluid compositions result in fluids which are susceptible to the formation of carboxylic acids (weak acids) during use in an aircraft.
- carboxylic acids weak acids
- the acid number of the phosphate ester based functional fluid can reach 1.6 mg KOH/g despite the presence of the epoxide acid scavenger in the fluid.
- the acidity is explained by the hydrolysis of the carboxylate group of the epoxide acid scavenger that lead to a weak carboxylic acid and an alcohol. This reaction is illustrated below: where R is an alkyl group containing from 2 to 12 carbon atoms.
- Carbodiimides are well known acid scavengers. Dr. Achim Fessenbecker, Rhein Chemie Rheinau GmbH (NLGI, vol. 61, 3, p. 10, 1996) disclosed that the Total Acid Number (TAN) of isopropylphenyl phosphate containing a carbodiimide was reduced in a coke bottle test as compared with the pure base fluid and thus carbodiimide was deemed capable of neutralizing strong acids as phosphoric acids.
- TAN Total Acid Number
- U.S. Pat. No. 6,235,687 relates to lubricating oils exhibiting anti-rust properties that are obtained by adding to the lubricating oil an acidic anti-rust additive and an acid scavenger such as carbodiimide, in a specific sequence.
- U.S. Pat. No. 5,614,483 relates to lubricant base materials containing ester groups that may be stabilized by adding a small quantity of carbodiimides and the service life lubricants manufactured therefrom may be decisively extended.
- U.S. Pat. No 6,143,702 discloses lubricating oils of enhanced oxidation stability that are obtained by adding to the lubricating oil a mixture comprising n-phenyl-1-naphthyl amine and an acid scavenger such as carbodiimide.
- the present invention is directed to a phosphate ester based functional fluid comprising a major amount of a organic phosphate ester base oil and a minor additive amount of a combination of alkyl epoxy and carbodiimide acid scavengers.
- the functional fluids of the present invention include a major amount of an organic phosphate ester base stock.
- Phosphate ester base fluids are generally of the formula: wherein each R is the same or different and selected from alkyl or alkoxy alkyl group having 2 to 20 carbon atoms, aryl groups (e.g., phenyl) and substituted aryl groups containing up to 20 carbon atoms where the substituents are alkyl, phenyl, alkyl phenyl or phenyl alkyl and wherein the alkyl group contain form 1 to 10 carbons.
- aryl groups e.g., phenyl
- substituted aryl groups containing up to 20 carbon atoms where the substituents are alkyl, phenyl, alkyl phenyl or phenyl alkyl and wherein the alkyl group contain form 1 to 10 carbons.
- Typical organo phosphate ester base stocks include esters selected from trialkyl phosphates, triaryl phosphates, dialkyl aryl phosphates, alkyl diaryl phosphates, and alkylated triaryl phosphates that contain from 3 to 8, preferably from 3 to 6, more preferably 3 to 5 carbon atoms in the alkyl groups and mixtures thereof.
- esters examples include tri-n-butyl phosphate, tri-isobutyl phosphate, tri-sec-butyl phosphate, di-isobutyl pentyl phosphate, tri-2-ethyl hexyl phosphate, n-butyl di-isobutyl phosphate, di-isobutyl n-butyl phosphate, n-butyl diphenyl phosphate, isobutyl diphenyl phosphate, di-isobutyl triphenyl phosphate, isopropylated triphenyl phosphates and butylated triphenyl phosphates.
- the trialkyl phosphate esters are those of tri-n-butyl phosphate, tri-isobutyl phosphate and mixtures thereof.
- the alkyl substituted phenyl groups of the triaryl phosphates include phenyl groups having from 1 to 3 alkyl substituents wherein the alkyl groups are straight a branched chain groups of form 1 to 14 carbon atoms and further, wherein each alkyl substituted phenyl group has a maximum of up to 20 carbons.
- Examples of triaryl phosphate esters include, by way of example tri(isopropyl phenyl)phosphate, tri(tert-butylated phenyl)phosphate, tri cresyl phosphate, and the like and mixtures thereof.
- Combinations of tri alkyl phosphates and tri aryl phosphates include a mixture of tributyl phosphate and tri(isopropylphenyl)phosphate at about a 6:1 to 7:1 ratio, and a mixture of tri butyl phosphate and tri(butylated phenyl)phosphate at about a 6:1 to 7:1 ratio.
- the organo phosphate ester base stock useful in the present invention therefore comprises about 10 to 100 wt % of a trialkyl phosphate, about 0 to 75 wt % of a dialkyl aryl phosphate, about 0 to 30 wt % of an alkyl diaryl phosphate and about 0 to 15 wt % of a triaryl phosphate.
- the alkyl groups of the esters contain 3 to 5 carbons, more preferably 3 to 4 carbons.
- the phosphate ester based fluid typically comprises a fire resistant phosphate ester base oil and a viscosity index improver, an acid scavenger and an erosion inhibitor.
- the fluid may also contain one or more rust inhibitors, one or more antioxidants, one or more metal corrosion inhibitor.
- the functional fluids of the present invention contain an anti-erosion additive to inhibit flow-induced electrochemical corrosion.
- Suitable erosion inhibitors are disclosed, for example, in U.S. Pat. Nos. 5,464,551 and 3,679,587, the entire disclosures of which are incorporated herein by reference in their entirety.
- Preferred erosion inhibitors include the alkali metal salts, and preferably the potassium salt, of a perfluoroalkyl or perfluoro-cycloalkyl sulfonate as disclosed in U.S. Pat. No. 3,679,587.
- Such perfluoroalkyl and perfluorocycloalkyl sulfonates preferably encompass alkyl groups of from 1 to 10 carbon atoms and cycloalkyl groups of from 3 to 10 carbon atoms.
- Suitable anti-erosion additives are alkali metal salts of perfluorooctyl sulfonic acids such as FC-98 or FC-95, from, for example, 3M, Minneapolis, Minn.
- the erosion inhibitor is employed in an amount effective to inhibit erosion in the power transmission mechanisms of an aircraft and, preferably, is employed in an amount of from about 0.01 to about 0.5 wt %, based on the total weight of the hydraulic fluid composition and more preferably from about 0.02 to about 0.1 wt %. Mixtures of such anti-erosion agents can be used.
- the functional fluids of the present invention also include from about 4 wt % to about 20 wt % of auxiliary additives as previously indicated selected from the group consisting of anti-oxidants, acid scavengers, viscosity index (VI) improvers, rust inhibitors, defoamers and metal corrosion inhibitors.
- auxiliary additives as previously indicated selected from the group consisting of anti-oxidants, acid scavengers, viscosity index (VI) improvers, rust inhibitors, defoamers and metal corrosion inhibitors.
- the hydraulic fluid compositions of this invention can further optionally comprise an antioxidant or mixture of antioxidants in an amount effective to inhibit oxidation of the hydraulic fluid or any of its components.
- Useful antioxidants include trialkylphenols, polyphenols, phenyl alpha naphthyl amines (PANA) and di(alkylphenyl) amines.
- antioxidants include, by way of example, phenolic antioxidants, such as 2,6-di-tert-buty-p-cresol, tetrakis[methylene(3,5-di-tert- butyl-4-hydroxyhydrocinnamate)]-methane (Irganox®1010 from Ciba Geigy), bis(3,5 di-tert-butyl-4 hydroxyphenyl)methane(Ethanox 702 from Ethyl corporation), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert butyl-4-hydroxyphenyl) benzene (Ethanox 330 from Ethyl Corporation) and the like; amine antioxidants including, by way of example, diarylamines, such as di(noctylphenyl)amine (Vanlube ® 81), phenyl- ⁇ -naphthylamine, (noctylphenyl)naphthylamine (Ir
- a preferred mixture of antioxidants comprises 2,6-di-tert-butyl-p-cresol and di(octylphenyl)amine (e.g., a 1:1 mixture).
- Another preferred mixture of antioxidants is 2,6-di-tert-butyl-p-cresol, di(octylphenyl)amine and 6-methyl- 2 , 4 -bis(octylthio)-methyl]-phenol (e.g., 1:2:4 mixture).
- Still another preferred mixture of antioxidants is 2,6-di-tert-butyl-p-cresol, di(octylphenyl)amine and tetrakis[methylene(3,5-di-tert-butyl- 4- hydroxyhydrocinnamate)]methane (e.g., a 1:2:3 mixture).
- the antioxidant or mixture of antioxidants is employed in an amount effective to inhibit oxidation of the hydraulic fluid.
- the antioxidant or mixture of antioxidants is employed in an amount ranging from about 0 to about 3 wt %, more preferably from about 0.5 to 2.5 wt % and still more preferably at from about 1 to 2 wt % based on the total weight of the hydraulic fluid composition.
- Viscosity Index Improver (VI) additives useful in hydraulic fluid compositions of this invention include polyacrylate esters and poly (alkyl methacrylate) esters of the type described in U.S. Pat. Nos. 5,817,606 and 3,718,596, the disclosures of which are incorporated herein by reference in their entirety.
- the viscosity index improver is of high molecular weight, having a number average molecular weight between about 50,000 and about 100,000 and a weight average molecular weight between about 200,000 and 350,000.
- Viscosity index improvers are commercially available from Rohm and Haas Company and referred to as poly (alkyl methacrylate) PA-7570, PA 6703, PA 6744 and PA 6961-PMN.
- the hydraulic fluid compositions of this invention can contain from about 3 wt % to about 10 wt % of the viscosity index improver (or an active ingredient basis), preferably about 4 to about 6 wt % (on an active ingredient basis) based on the total weight of the functional fluid composition.
- the VI improver can be mixed with a portion of the phosphate ester base stock, typically as a 1:1 mixture and then added to the balance of the functional fluid.
- Rust inhibitors suitable in this invention include metal corrosion inhibitors such as benzotriole derivatives and dihydroimidazole derivatives such as Amine-O commercially available from Ciba-Geigy and Vanlube RI-G commercially available from Vanderbilt.
- metal corrosion inhibitors such as benzotriole derivatives and dihydroimidazole derivatives such as Amine-O commercially available from Ciba-Geigy and Vanlube RI-G commercially available from Vanderbilt.
- Other suitable rust inhibitors include those described in U.S. Pat. Nos. 5,035,084, 4,206,067 and 5,464,551 the entire disclosures of which are incorporated herein by reference in their entirely.
- Additional non-limiting examples include calcium dinonylnaphthalene sulfonate, a Group I or Group II metal overbased and/or sulfurized phenate, sulfonate or carboxylate, a compound of the formula: R 4 N[CH 2 CH(R 5 )OH] 2 wherein R 4 is selected from the group consisting of alkyl of from 1 to 40 carbon atoms, —COOR 6 and —CH 2 CH 2 N[CH 2 CH(R5)OH] 2 where R 6 is alkyl of from 1 to 40 carbon atoms, and each R 5 is independently selected from the group con-sisting of hydrogen and methyl, including N,N,N′,N′-tetrakis(2-hydroxypropyl) ethylene diamine and N,N-bis(2-hydroxyethyl) tallowamine (e.g., N tallow amine alkyl-2,2′-iminobisethanol, sold under the trade name Ethomeen T 12), and diphenyl dithioethane
- the Group I and Group II metal overbased and/or sulfurized phenates preferably are either sulfurized Group I or Group II metal phenates (without CO 2 added) having a Total Base Number (TBN) of from greater than 0 to about 200 or a Group I or Group II metal overbased sulfurized phenate having a TBN of from 75 to 400 prepared by the addition of carbon dioxide during the preparation of the phenate. More preferably, the metal phenate is a potassium or calcium phenate. The phenate advantageously modifies the pH to provide enhanced hydrolytic stability.
- Each of these components are either commercially available or can be prepared by art recognized methods.
- Group II metal overbased sulfurized phenates are commercially available from Chevron Chemical Company, San Ramon, Calif. under the trade name OLOA® including, OLOA 219®, OLOA 216Q® and the like and are described by Campbell, U.S. Pat. No. 5,318,710, and by MacKinnon, U.S. Pat. No. 4,206,067.
- OLOA® including, OLOA 219®, OLOA 216Q® and the like and are described by Campbell, U.S. Pat. No. 5,318,710, and by MacKinnon, U.S. Pat. No. 4,206,067.
- N,N,N′,N′ -tetrakis (2-hydroxy-propyl)ethylenediamine is disclosed by MacKinnon, U.S. Pat. No 4,324,674. The disclosures of each of these patents are incorporated herein by reference in their entirety.
- Group I or II metal dinonylnaphthalene sulfonates such as calcium dinonylnaphthalene sulfonate (Na-Sul 729 commercially available from King industries) may also be used as a rust inhibitor in the hydraulic fluid composition in an amount ranging from 0.2 to 1.0 wt % of the hydraulic fluid composition.
- the rust inhibitor or mixture of rust inhibitors is employed in an amount effective to inhibit the formation of rust.
- the rust inhibitor is employed in an amount ranging from about 0 to about 1 wt %, preferably 0.001 to about 1 wt %, more preferably about 0.005 to about 0.5 wt %, and still more preferably at about 0.01 to 0.1 wt % based on the total weight of the hydraulic fluid composition.
- the rust inhibitor comprises a mixture of N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine and a Group II metal overbased phenate (e.g., a 5:1 mixture).
- the rust inhibitor comprises a mixture of N,N-bis(2-hydroxyethyl)tallowamine (Ethomeen® T 12) and a Group II metal overbased phenate (e.g., a 5:1 mixture).
- the functional fluid compositions of this invention further comprise an acid control additive, acid receptor, or acid scavenger (all three terms used as synonyms in the patent and public literature) in an amount sufficient to neutralize acids formed in such functional fluids, especially functional fluids utilized as aircraft hydraulic fluids, such as phosphoric acid and its partial esters.
- an acid control additive such as phosphoric acid and its partial esters.
- Suitable acid control additives are described, for example, in U.S. Pat. Nos. 5,464,551, 3,723,320 and 4,206,067, the disclosures of which are incorporated herein in their entirety.
- Preferred acid control additives have the formula: where R is selected from the group consisting of an alkyl group of from 1 to 10 carbon atoms, substituted alkyl of from 1 to 10 carbon atoms and containing from 1 to 4 ether oxygen atoms therein and cycloalkyl of from 3 to 10 carbon atoms, each R′ is independently selected from the group consisting of hydrogen, alkyl of from 1 to 10 carbon atoms and —C(O)OR′′ where R′′ is alkyl of from 1 to 10 carbon atoms optionally containing from 1 to 4 ether oxygen atoms, therein or cycloalkyl of from 3 to 10 carbon atoms.
- Preferred acid scavengers of the above formula are the monoepoxide 2-ethylhexyl 7-oxabicyclo[4.1.0]heptane-3-carboxylic acid, which is disclosed in U.S. Pat. No. 3,723,320, or mono epoxide 2- (ethoxy ethoxy)ethyl7+L-OXABICYCLO [4.1.0]heptane-3-carboxylate or mixtures thereof, and monoepoxide 7-oxa-bicyclo [4.1.0]-heptane-3,4-dicarboxylic acid, dialkyl esters (e.g., the di-isobutyl ester).
- dialkyl esters e.g., the di-isobutyl ester
- Dialkyl esters of this monoepoxide are also disclosed in U.S. Pat. No. 3,723,320.
- the trialkyl and tetraalkyl esters are prepared via conventional Diels-Alder reaction procedures via a suitable unsaturated trialkyl or tetraalkyl ester and a suitable 1,3-diene.
- the Diels-Alder reaction provides for 4 +2 cyclo addition to provide for a cyclohexene derivative having the suitable trialkyl or tetraalkyl esters.
- the unsaturation in the cyclohexane is utilized to provide for epoxide formation via conventional methods.
- Suitable unsaturated trialkyl and tetraalkyl esters are known in the art.
- tetraethyl ethylene tetracarboxylate is available from Fluka (Ronkonoma, N.Y.).
- the alkyl groups of this tetraethyl ester can readily be exchanged via conventional techniques to provide for other esters as defined above.
- the acid control additive whether as mono- di-, tri- or tetra-ester is employed in an amount effective to scavenge the acid generated, typically as partial esters of phosphoric acid, during use of the functional fluid, especially during use as an aircraft hydraulic fluid.
- the acid control additive is employed in an amount ranging from about 4 to about 10 wt %, based on the total weight of the hydraulic fluid composition, and more preferably from 5 to 8 wt % and still more preferably from 6 to 8 wt %, based on the total weight of the fluid.
- Carbodiimides suitable in this invention might be mono carbodiimides or poly carbodiimides.
- Useful carbodiimides are illustrated by the following structural formula R 1 —(N ⁇ C ⁇ N) n —R 2 wherein R 1 and R 2 are the same or different and are hydrogen, hydrocarbyl groups, preferably hydrocarbyl group containing 1 to 20 carbons, more preferably 1 to 18 carbons, or nitrogen and/or oxygen containing hydrocarbyl groups and n is 1 to 5, preferably 1 or 2.
- R 1 and R 2 can be C 1 -C 12 aliphatic groups, C 6 -C 18 aromatic groups or aromatic-aliphatic groups.
- R 1 and R 2 may be, for example, hydrogen, alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, 2-methylbutyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl and the like, alkenyl groups such as propenyl, butenyl, isobutenyl, pentenyl, 2-ethylhexenyl, octenyl and the like, cycloalkyl groups such as cyclopentyl, cyclohexyl, methyl-cyclopentyl, ethylcyclopentyl and the like, aryl groups such as alkyl substituted phenyl groups for example toluyl, isopropylphenyl, diisopropylphenyl and the like,
- di-isopropyl carbodiimide di-n-butyl carbodiimide, methyl-tert-butyl carbodiimide, diphenyl carbodiimide, di-p-tolyl carbodiimide, 2,2′-diethyl-diphenyl carbodiimide, 2,2 ′-diethoxy-diphenyl carbodiimide, 2,2 ′, 6,6′-tetraethyldiphenyl carbodiimide and the like.
- the preferred carbodiimide is the 2,2′,6,6′-tetraisopropyldiphenyl carbodiimide such as Additin® RC8500 commercially available from Rheine Chemie.
- Carbodiimides wherein n is greater than 1 are polycarbodiimides exemplified by the following:
- aromatic polyiso-cyanates such as 1,3-di-isopropyl-phenylene-2,4-isocyanate, 1-methyl-3,5-diethyl-phenylene-2,4-diisocyanate and 3,5,3′,5′-tetra-isopropyl-diphenyl-methane-4,4-di-isocyanate in the presence of tertiary amines, basically reacting metal compounds, carboxylic acid metal salts or non-basic organometal compounds at a temperature of at least 120° C., according to the process disclosed in German Patent 1,156,401.
- Typical amounts of carbodiimide additive that can be used in the functional fluid compositions of this invention are from about 0.05 to about 5.0 wt %, based on total weight of fluid, preferably from 0.5 to 3 wt % based on total weight of fluid.
- the epoxide employed was 2-ethylhexyl-7-oxabicyclo [4.1.0]heptane-3-carboxylic acid. Acid number was determined by ASTM D-974.
- Fluid 1 a used phosphate ester based hydraulic fluid (Fluid 1) that contained 1.73% of residual epoxide acid scavenger was stirred at 40° C. for 72 hours with 0.1 gm (0.276 mmole) carbodiimide RC 8500 (Fluid 2), and with 0.1 gm (0.387 mmole) epoxide acid scavenger (Fluid 3).
- the Fluid 1 had an initial acid number of 1.2 mg KOH/g attributable to the presence of carboxylic acids.
- Fluid 2 of this invention containing the carbodiimide gave a 63.7% acid number reduction whereas Fluid 3 with additional epoxide acid scavenger gave 27.1 % acid number reduction, showing that the mere addition of more epoxide is not sufficient to control the acidity attributable to weak carboxylic acids in the fluids.
- Example 2 demonstrates that whereas in Example 2 it is shown that carbodiimides are good acid scavengers for weak carboxylic acids, the carbodiimides such as RC 8500 are poor acid scavengers for the alkyl phosphoric acids produced from the hydrolysis of the phosphate esters.
- About 15 mL of the fluid was placed in sealed glass ampoules with a piece of copper and steel wires to catalyze the hydrolysis.
- the fluid was spiked with water to make total water content of 0.5 wt %.
- the ampoules were placed in an oven at 150° C.
- the Acid Number was determined as a function of time. The test is completed when the Acid Number of the fluid has reached 1.5 mg KOH/g (fluid life).
- Fluid 7 containing 8.0 wt % carbodiimide reached a 3.08 mg KOH/g after only 48 hours whereas Fluid 8 containing only the epoxide acid scavenger went to 244 hours before reaching an Acid Number of 1.59 mg KOH/g.
- the combination of 1 wt % carbodiimide and 5.0 wt % epoxide (Fluid 9) performed well and reached an Acid Number of 1.88 mg KOH/g after 222 hours. It is important to note that Fluid 9 contained 0.7 wt % less epoxide than Fluid 8.
- a fresh portion of a phosphate ester hydraulic fluid which did not contain any acid scavengers was spiked with cekanoic acid to produce a test fluid 10, the acid number of which was measured as 1.5.
- This test fluid 10 was then treated with epoxide alone, carbodiimide along and with a mixture of epoxide and carbodiimide.
- the fluids (Fluid 11, Fluid 12, Fluid 13 and Fluid 14) are presented in Table 5 and the data after 72 hours show that the mixture of the carbodiimide and epoxide (Fluid 14) reduces the acid number to a greater extent then just the epoxide alone at 5.70 g epoxide dose (Fluid 11) or carbodiimide alone at 1.0 g carbodiimide dose (Fluid 12).
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Chemistry (AREA)
- Lubricants (AREA)
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/484,206 US20070021311A1 (en) | 2005-07-19 | 2006-07-11 | Aviation phosphate ester functional fluids with enhanced acid scavenging properties |
EP06787409A EP1920033A2 (en) | 2005-07-19 | 2006-07-14 | Aviation phosphate ester functional fluids with enhanced acid scavenging properties |
PCT/US2006/027497 WO2007011783A2 (en) | 2005-07-19 | 2006-07-14 | Aviation phosphate ester functional fluids with enhanced acid scavenging properties |
JP2008522846A JP2009503142A (ja) | 2005-07-19 | 2006-07-14 | 酸捕捉特性が強化された航空機のリン酸エステル機能性流体 |
CA002615891A CA2615891A1 (en) | 2005-07-19 | 2006-07-14 | Aviation phosphate ester functional fluids with enhanced acid scavenging properties |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US70070005P | 2005-07-19 | 2005-07-19 | |
US11/484,206 US20070021311A1 (en) | 2005-07-19 | 2006-07-11 | Aviation phosphate ester functional fluids with enhanced acid scavenging properties |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070021311A1 true US20070021311A1 (en) | 2007-01-25 |
Family
ID=37669420
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/484,206 Abandoned US20070021311A1 (en) | 2005-07-19 | 2006-07-11 | Aviation phosphate ester functional fluids with enhanced acid scavenging properties |
Country Status (5)
Country | Link |
---|---|
US (1) | US20070021311A1 (ja) |
EP (1) | EP1920033A2 (ja) |
JP (1) | JP2009503142A (ja) |
CA (1) | CA2615891A1 (ja) |
WO (1) | WO2007011783A2 (ja) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010097358A1 (de) * | 2009-02-25 | 2010-09-02 | Rhein Chemie Rheinau Gmbh | Transformatorölzusammensetzung, umfassend mindestens einen säurefänger |
WO2014180833A1 (de) * | 2013-05-07 | 2014-11-13 | Rhein Chemie Rheinau Gmbh | Verfahren zur herstellung von ölformulierungen mittels bestimmter carbodiimide |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2024004763A1 (ja) * | 2022-06-27 | 2024-01-04 | 三洋化成工業株式会社 | 粘度指数向上剤組成物及び潤滑油組成物 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030047709A1 (en) * | 2001-04-20 | 2003-03-13 | Marc-Andre Poirier | Monoepoxycyclohexyl carboxylates and aircraft hydraulic fluids containing same |
US6750182B1 (en) * | 1998-10-09 | 2004-06-15 | Exxonmobil Research And Engineering Company | Polar oil based industrial oils with enhanced sludge performance |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6445004B1 (en) * | 1998-02-26 | 2002-09-03 | Samsung Electronics Co., Ltd. | Composition for a wiring, a wiring using the composition, manufacturing method thereof, a display using the wiring and a manufacturing method thereof |
-
2006
- 2006-07-11 US US11/484,206 patent/US20070021311A1/en not_active Abandoned
- 2006-07-14 WO PCT/US2006/027497 patent/WO2007011783A2/en active Application Filing
- 2006-07-14 CA CA002615891A patent/CA2615891A1/en not_active Abandoned
- 2006-07-14 EP EP06787409A patent/EP1920033A2/en active Pending
- 2006-07-14 JP JP2008522846A patent/JP2009503142A/ja active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6750182B1 (en) * | 1998-10-09 | 2004-06-15 | Exxonmobil Research And Engineering Company | Polar oil based industrial oils with enhanced sludge performance |
US20030047709A1 (en) * | 2001-04-20 | 2003-03-13 | Marc-Andre Poirier | Monoepoxycyclohexyl carboxylates and aircraft hydraulic fluids containing same |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010097358A1 (de) * | 2009-02-25 | 2010-09-02 | Rhein Chemie Rheinau Gmbh | Transformatorölzusammensetzung, umfassend mindestens einen säurefänger |
CN102326217A (zh) * | 2009-02-25 | 2012-01-18 | 莱茵化学莱瑙有限公司 | 包括至少一种酸阻止剂的变压器油组合物 |
WO2014180833A1 (de) * | 2013-05-07 | 2014-11-13 | Rhein Chemie Rheinau Gmbh | Verfahren zur herstellung von ölformulierungen mittels bestimmter carbodiimide |
US9464256B2 (en) * | 2013-05-07 | 2016-10-11 | Rhein Chemie Rheinau Gmbh | Methods for producing oil formulations by means of certain carbodiimides |
RU2664536C2 (ru) * | 2013-05-07 | 2018-08-20 | Лэнксесс Дойчланд Гмбх | Способ получения масляных композиций с помощью определенных карбодиимидов |
Also Published As
Publication number | Publication date |
---|---|
WO2007011783A2 (en) | 2007-01-25 |
CA2615891A1 (en) | 2007-01-25 |
WO2007011783A3 (en) | 2007-10-04 |
JP2009503142A (ja) | 2009-01-29 |
EP1920033A2 (en) | 2008-05-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0719851B1 (en) | Lubricating oil composition | |
RU2555703C2 (ru) | Смазочные композиции | |
CA1063590A (en) | Antiwear hydraulic oil | |
JP2007520618A (ja) | 酸化防止剤ブレンドを含む潤滑剤組成物 | |
EP1746148B1 (en) | Crankcase lubricating oil composition for protection of silver bearings in locomotive diesel engines. | |
SG181737A1 (en) | System lubricant oil composition for crosshead-type diesel engine | |
US6649080B2 (en) | Phosphate ester base stocks and aircraft hydraulic fluids comprising the same | |
US9321979B2 (en) | Friction modifier composition for lubricants | |
CN113493715B (zh) | 一种液压油添加剂组合物 | |
US6254799B1 (en) | Phosphate ester base stocks comprising mixed n-butyl/isobutyl phosphate esters and aircraft hydraulic fluids comprising the same | |
US6703355B2 (en) | Method for lubricating high pressure hydraulic system using phosphate ester hydraulic fluid | |
US20070021311A1 (en) | Aviation phosphate ester functional fluids with enhanced acid scavenging properties | |
EP0871690A4 (ja) | ||
WO1996017517A9 (en) | Hydraulic fluids for use in aircraft | |
US20230287290A1 (en) | Lubricant composition for automotive transmission | |
US6391225B1 (en) | Phosphate ester hydraulic fluids with improved properties (law935) | |
US20180320103A1 (en) | Lubricating Oil Composition for Internal Combustion Engine | |
US11697785B2 (en) | Lubricant composition for a gas engine | |
CN109715770A (zh) | 用于硅氧烷沉积物控制的发动机润滑剂 | |
US9994789B2 (en) | Friction modifier composition for lubricants | |
US7910529B2 (en) | Functional fluid compositions | |
US12098348B2 (en) | Lubricant composition for oxidation-stable automotive transmission | |
WO2000024848A1 (en) | Phosphate ester base stocks and aircraft hydraulic fluids comprising the same | |
US20230295532A1 (en) | Lubricant composition for automotive transmission having improved anticorrosion properties | |
US20230303945A1 (en) | Lubricant composition for oxidation-stable automotive transmission |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: EXXONMOBIL RESEARCH AND ENGINEERING COMPANY, NEW J Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:POIRIER, MARC-ANDRE;FELSKY, GERALD;REEL/FRAME:018349/0460;SIGNING DATES FROM 20060809 TO 20060831 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |