With Organic Non-carboxylic Acid Ester Chalcogen Compound Or Nitrogen Compound Patents (Class 508/495)
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Patent number: 12234424Abstract: Provided herein are hydrocarbon compositions suitable for use as a lubricant comprising sulfur between about 30 ppm to about 220 ppm, and aromatics between about 0.2 wt. % to about 3 wt. %. The present hydrocarbon compositions comprise a blend of one or more base stocks and a high-sulfur containing material and can demonstrate an improved oxidation performance as a lubricant in weighted piston deposit merits and/or by viscosity increase.Type: GrantFiled: February 12, 2021Date of Patent: February 25, 2025Assignee: Exxon Mobil Technology and Engineering CompanyInventors: Joshua D. Catanach, Clara Rodrigue, Christine A. Zielinski, Charles L. Baker, Jr., Richard C. Dougherty, Min Chen
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Patent number: 10995295Abstract: The present invention relates to the use of lubricants on the basis of water-soluble, high-viscosity polyethylene glycols for lubricating open gearing, which is for example used in rotary kilns and mills.Type: GrantFiled: September 20, 2017Date of Patent: May 4, 2021Assignee: Klüber Lubrication München SE & CO. KGInventors: Daniel Andreas Narnhammer, Stefan Seemeyer, Justin Koozer, Ari-Pekka Holm
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Patent number: 10723969Abstract: Lubricant compositions comprising a lubricating oil and a mixture of one or more alkylated diarylamine and one or more alkylated hydroxydiarylamine exhibit excellent antioxidant and deposit control performance.Type: GrantFiled: September 13, 2017Date of Patent: July 28, 2020Assignee: LANXESS Solutions US Inc.Inventors: Robert G. Rowland, Subban Ramesh
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Patent number: 10351793Abstract: The present invention provides a refrigerating machine oil comprising: a base oil containing an ester of dipentaerythritol with 2-methylbutanoic acid and n-pentanoic acid; and at least one epoxy compound selected from the group consisting of a glycidyl ester compound and a glycidyl ether compound, the refrigerating machine oil being used with a difluoromethane refrigerant.Type: GrantFiled: February 10, 2016Date of Patent: July 16, 2019Assignee: JXTG Nippon Oil & Energy CorporationInventors: Hitoshi Takahashi, Takeshi Okido, Souichirou Konno
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Patent number: 9228128Abstract: The present invention relates in part to a container for stabilized chloropropenes, such as 1,1,2,3-tetrachloropropene, otherwise known to decompose and degrade, and to the resulting stabilized chloropropene, using a morpholine compound and/or a trialkyl phosphate compound as defined herein. Such stabilized chloropropenes are useful in the manufacture of hydrofluoroolefins such as 2,3,3,3-tetrafluoroprop-1-ene (1234yf).Type: GrantFiled: August 11, 2014Date of Patent: January 5, 2016Assignee: HONEYWELL INTERNATIONAL INC.Inventors: Haluk Kopkalli, Haiyou Wang, Hsueh Sung Tung, Daniel C. Merkel
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Publication number: 20140326117Abstract: The invention provides a water-soluble metal-working oil agent, including a component A, a component B, a component C, and a component D, wherein the component A is an ester compound which has a characteristic temperature, as measured in accordance with JIS K2242, of 570° C. or higher and which is contained in the water-soluble metal-working oil agent in an amount of 10 mass % or more with respect to the entire amount of the agent; the component B is at least one condensed fatty acid which is selected from a condensed fatty acid (1), produced through dehydration condensation of a hydroxycarboxylic acid, and a condensed fatty acid (2), produced through dehydration condensation of an alcoholic hydroxyl group of the condensed fatty acid (1) with a monovalent carboxylic acid, which has a characteristic temperature, as measured in accordance with JIS K2242, of 650° C. or higher, and which is contained in the water-soluble metal-working oil agent in an amount of 7.Type: ApplicationFiled: November 15, 2012Publication date: November 6, 2014Applicant: IDEMITSU KOSAN CO., LTD.Inventors: Fumiaki Takagi, Yoichiro Jido
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Publication number: 20140274846Abstract: The present invention is directed toward compositions suitable for use as dielectric fluids, lubricant fluids and biodiesel fluids. Compositions described herein are obtained from a saturated, unsaturated or combinations of both monol, diol, triol or polyol acyl ester based fluid and/or a non-ester based fluid and 2,4,6-tris(di-C1-C6-alkylaminomethyl)phenol and/or the carboxylic acid salt of 2,4,6-tris(di-C1-C6-alkylaminomethyl)phenol. These compositions demonstrate improved oxidative stability and/or hydrolytic stability at higher use temperatures.Type: ApplicationFiled: March 11, 2014Publication date: September 18, 2014Applicant: E I DU PONT DE NEMOURS AND COMPANYInventors: HARI BABU SUNKARA, Raja Hari Poladi
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Patent number: 8299004Abstract: A hydraulic fluid of the present invention contains, as a base oil, an ester having two or more ring structures, the two or more ring structures being at least one selected from an aromatic ring and a saturated naphthenic ring. Particularly, the hydraulic fluid contains an ester having two or more aromatic rings as the base oil. The hydraulic fluid has low energy loss due to compression and exhibits excellent responsiveness when being used in a hydraulic circuit. Consequently, the hydraulic fluid realizes energy-saving, high-speed operation and high precision of control in the hydraulic circuit.Type: GrantFiled: April 21, 2008Date of Patent: October 30, 2012Assignee: Idemitsu Kosan Co., Ltd.Inventor: Toshiyuki Tsubouchi
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Patent number: 7052626Abstract: A fluid composition for a refrigerator, which comprises a chlorine-free fluorocarbon refrigerant and a refrigerator oil, said refrigerator oil consisting essentially of a tetraester of pentaerythritol of formula (1) with both 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid, said refrigerator oil exhibiting a pour point not higher than ?10° C.Type: GrantFiled: April 9, 1998Date of Patent: May 30, 2006Assignee: Nippon Mitsubishi Oil CorporationInventors: Hiroshi Hasegawa, Noboru Ishida, Umekichi Sasaki, Tatsuyuki Ishikawa
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Patent number: 6998065Abstract: A refrigerator oil for use in compressors using therein a hydrogen-containing halogenocarbon as a refrigerant, consisting essentially of as a base oil at least one kind of an ester selected from the group consisting of a specific pentaerythritol ester such as an ester of pentaerythritol with a mono- or dicarboxylic acid, a specific polyol ester such as an ester of trimethylolethane with a mono- or dicarboxylic acid, a specific ester such as an ester of ethylene glycol and a dicarboxylic acid, and a specific polyol ester synthesized from a neopentyl type polyhydric alcohol, a monocarboxylic acid and a dicarboxylic acid; and further comprising at least one kind of an epoxy compound.Type: GrantFiled: September 14, 1998Date of Patent: February 14, 2006Assignee: Nippon Mitsubishi Oil CorporationInventors: Hiroshi Hasegawa, Noboru Ishida, Umekichi Sasaki, Tatsuyuki Ishikawa
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Patent number: 6858569Abstract: Cutting or grinding oil compositions which are suitable for use in a minimal quantity lubrication system in which a minimal quantity of an oil is supplied to the spot to be cut or ground of a work, together with air are reduced in stickiness and improved in lubricity.Type: GrantFiled: June 25, 2001Date of Patent: February 22, 2005Assignee: Nippon Mitsubishi Oil CorporationInventors: Hideo Yokota, Noboru Aota, Yoshitaka Natsume, Masanori Ibi, Minoru Okajima, Ichiro Inezaki, Toshiaki Wakabayashi, Satoshi Suda
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Patent number: 6844301Abstract: A synthetic ester-containing lubricant with good soot-handling and, with friction modifier, viscosity modifier and antioxidant present, improved engine performance and cleanliness.Type: GrantFiled: September 5, 2002Date of Patent: January 18, 2005Assignees: Infineum USA LP, Fina Research S.A.Inventors: Ian Peter Field, Etienne Marc Tamigniau
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Patent number: 6841522Abstract: This invention relates to lubricant compositions comprising a polyalkylene glycol and an ester wherein the polyalkylene glycol has the formula (I): RO—(CH2CH(CH3)O)n—CH3 where R is an alkyl group with 1 to 15 carbon atoms and n=1 to 35. The lubricant compositions of the invention do not readily form stable emulsions with water. This feature makes the lubricant compositions of the invention particularly suitable for use with air compressors where it is very difficult to exclude moisture.Type: GrantFiled: April 27, 2001Date of Patent: January 11, 2005Assignee: Imperial Chemical Industries PLCInventors: Mitchell Corner, Peter Timothy Gibb, Steven James Randles, Robert Ian George Thompson
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Patent number: 6586376Abstract: A heat resistant lubricating oil composition which exhibits high heat resistance and oxidation resistance under high temperature conditions, and can withstand severe working conditions, as in jet engine turbines. The lubricating oil composition comprises a polyphenylthioether of formula I in a lubricating base oil, comprising any one of a polyol ester, a polyphenyl ether, an organopolysiloxane and mixtures thereof.Type: GrantFiled: April 14, 2000Date of Patent: July 1, 2003Assignee: ExxonMobil Research and Engineering CompanyInventors: Hiroshi Nakanishi, Ko Onodera, Makoto Kanbara, Atsuhisa Kobori, Yoshinobu Nakamura
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Patent number: 6582621Abstract: A refrigerator oil for use in compressors using therein a hydrogen-containing halogenocarbon as a refrigerant, consisting essentially of as a base oil at least one kind of an ester selected from the group consisting of a specific pentaerythritol ester such as an ester of pentaerythritol with a mono- or dicarboxylic acid, a specific polyol ester such as an ester of trimethylolethane with a mono- or dicarboxylic acid, a specific ester such as an ester of ethylene glycol and a dicarboxylic acid, and a specific polyol ester synthesized from a neopentyl type polyhydric alcohol, a monocarboxylic acid and a dicarboxylic acid; and further comprising at least one kind of an epoxy compound.Type: GrantFiled: October 4, 1995Date of Patent: June 24, 2003Assignee: Nippon Mitsubishi Oil CorporationInventors: Umekichi Sasaki, Tatsuyuki Ishikawa, Hiroshi Hasegawa, Noboru Ishida
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Patent number: 6444626Abstract: A synthetic lubricant composition is a blend of a polyol ester admixed with effective amounts of an antioxidant, yellow metal pacifier and rust inhibitors. The polyol ester blend includes a major proportion of poly(neopentyl polyol) ester blend formed by reacting poly(pentaerythritol) partial esters with at least one C7 to C12 carboxylic acid mixed with an ester formed by reacting a polyol having at least two hydroxyl groups and at least one C8-C10 carboxylic acid. Preferably, the acids are linear and avoid those which can cause odors during use. Effective additives include secondary arylamine antioxidants, triazole derivative yellow metal pacifier and an amino acid derivative and substituted primary and secondary amine and/or diamine rust inhibitor.Type: GrantFiled: May 8, 2000Date of Patent: September 3, 2002Assignee: Hatco CorporationInventors: Michael A. McHenry, Dale D. Carr, Thomas G. Schaefer
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Publication number: 20020035043Abstract: Cutting or grinding oil compositions which are suitable for use in a minimal quantity lubrication system in which a minimal quantity of an oil is supplied to the spot to be cut or ground of a work, together with air are reduced in stickiness and improved in lubricity.Type: ApplicationFiled: June 25, 2001Publication date: March 21, 2002Applicant: Nippon Mitsubishi Oil CorporationInventors: Hideo Yokota, Noboru Aota, Yoshitaka Natsume, Masanori IBI, Minoru Okajima, Ichiro Inezaki, Toshiaki Wakabayashi, Satoshi Suda
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Publication number: 20020002122Abstract: This invention relates to lubricant compositions comprising a polyalkylene glycol and an ester wherein the polyalkylene glycol has the formula:Type: ApplicationFiled: April 27, 2001Publication date: January 3, 2002Inventors: Mitchell Corner, Peter Timothy Gibb, Steven James Randles, Robert Ian George Thompson
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Patent number: 6255262Abstract: A process for reproducibly forming a thermally and oxidatively stable high hydroxyl glycerol di-ester compound which is particularly useful as a lubricant. The glycerol di-ester compound is formed by reacting a glycidyl ester with an excess of a neo acid salt. The di-ester product is produced in a nearly quantitative conversion and is readily recoverable from the reaction mixture via a water wash, vacuum dry, and a mild wiped film evaporator treatment.Type: GrantFiled: November 9, 1998Date of Patent: July 3, 2001Assignee: Exxon Chemical Patents Inc.Inventors: Michael J. Keenan, Martin A. Krevalis, David W. Turner
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Patent number: 6194359Abstract: The operational fluid according to the invention is well suited for the lifelong lubrication and cooling of combustion engines. It comprises as the basic fluid a polyalkylene glycol produced from ethylene oxide and propylene oxide and an additive mixture comprising a) 0.012-1.0 percent by weight of a reaction product of diphenyl amine and 2,4,4-trimethyl pentene; b) 0.01-1.0 percent by weight of a pentaerythritol partially or completely esterified with an alkyl-substituted p-hydroxy propionic acid; c) 0.01-1.0 percent by weight of a mono- or di-(C4-C8) alkyl phosphoric acid (C10-C15) alkyl amide; d) 0.01-1.0 percent by weight of triphenyl thiophosphate; e) 0.01-0.1 percent by weight of a tolutriazol amino-methylated with a straight-chain or branched alkyl group with 2-10 carbon atoms, and/or f) 0.01-0.1 percent by weight of 1H-benzotriazol.Type: GrantFiled: May 14, 1999Date of Patent: February 27, 2001Assignees: Fragol Schmierstoff GmbH & Co. KG, DaimlerChrysler AGInventors: Ludwig Beyer, Herbert Gasthuber, Heiner Müske, Mathias Woydt
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Patent number: 6191080Abstract: A heat resistant lubricating oil composition which exhibits high heat resistance and oxidation resistance under high temperature conditions, and can withstand severe working conditions, as in jet engines or gas turbines. The lubricating oil composition comprises a polyphenylthioether of formula {I} in a lubricating base oil, comprising any one of a polyol ester, dibasic acid ester, a polyphenyl ether, an organopolysiloxane and admixtures thereof.Type: GrantFiled: February 14, 1997Date of Patent: February 20, 2001Assignee: Tonen CorporationInventors: Hiroshi Nakanishi, Ko Onodera, Makoto Kanbara, Atsuhisa Kobori, Yoshinobu Nakamura
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Patent number: 6080705Abstract: This invention provides a refrigerator oil, a working fluid for a refrigerator, and a method for lubricating a refrigeration system, which can inhibit the creation of deposits attributable to metal working oils remaining within a refrigeration system. The refrigerator oil contains: a polyhydric alcohol ester compound as a lube base oil, and 0.5 to 4.5% by weight of at least one polyoxyalkylene compound. The working fluid for a refrigerator, containing: the above refrigerator oil, and a hydrofluorocarbon refrigerant. A method for lubricating a refrigeration system contaminated with metal working oils, containing a component sparingly soluble in the polyhydric alcohol ester compound or the hydrofluorocarbon refrigerant, or metal working oils, containing a component highly reactive with the polyhydric alcohol ester compound or the hydrofluorocarbon refrigerant, remaining therein, wherein the above working fluid for a refrigerator is used as a working fluid.Type: GrantFiled: April 28, 1998Date of Patent: June 27, 2000Assignee: Japan Energy CorporationInventors: Takashi Kaimai, Hitoshi Takahashi
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Patent number: 5998340Abstract: A lubricant containing a branched aliphatic diester of the general formula: R.sub.1 R.sub.2 R.sub.3 C--(CH.sub.2).sub.n --X--R--X'--(CH.sub.2).sub.n --CR.sub.4 R.sub.5 R.sub.6 in which R.sub.1 to R.sub.6 independently represent a hydrocarbon group having 1-18 carbon atoms; R is a fluorinated hydrocarbon group having 6 to 18 carbon atoms; either one of X and X' represent either one of --OCO-- and --COO--, while the other of X and X' represent the other of --OCO-- and --COO--; and n is an integer from 0 to 6, and optionally an aliphatic amine of the general formula: R.sub.7 NR.sub.8 R.sub.9 in which R.sub.7, R.sub.8 and R.sub.9 independently represent a hydrogen atom or a hydrocarbon group having 1 to 26 carbon atoms.Type: GrantFiled: March 6, 1998Date of Patent: December 7, 1999Assignee: Hitachi Maxell, Ltd.Inventors: Takahiro Furutani, Sayaka Shinomoto, Kazushi Miyata
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Patent number: 5955403Abstract: A sulfur free lubricating composition comprises a major portion of a synthetic base lubricating oil and a minor portion of a tri(alkyl phenyl) phosphate or di(alkylphenyl)phosphoric acid antiwear agent, an amine antioxidant a substituted succinamide rust inhibitor and a tolytriazole. The tri(alkylphenyl)phosphate antiwear agent is incorporated in the oil in an amount ranging between about 0.1 to 2.0 wt % and the amine antioxidant in amount ranging from about 0.1 to 5 wt %. The succinamide is present in an amount ranging from about 0.01 to 0.5 wt % and the tolytriazole, from about 0.01 to 0.5 wt %. In the foregoing, the wt % is based on the weight of oil.Type: GrantFiled: March 24, 1998Date of Patent: September 21, 1999Assignee: Exxon Research and Engineering CompanyInventor: Chung-Lai Wong
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Patent number: 5895778Abstract: A synthetic lubricant composition is a blend of a polyol ester blend admixed with effective amounts of an antioxidant, yellow metal pacifier and rust inhibitors. The polyol ester blend includes a major proportion of poly(neopentyl polyol) ester blend formed by reacting poly(pentaerythritol) with at least one C.sub.7 to C.sub.12 carboxylic acid mixed with an ester formed by reacting a polyol having at least two hydroxyl groups and at least one C.sub.8 -C.sub.10 carboxylic acid. Preferably, the acids are linear and avoid those which can cause odors during use. Effective additives include secondary arylamine antioxidants, triozole derivative yellow metal pacifier and an amino acid derivative and substituted primary and secondary amine and/or diamine rust inhibitor.Type: GrantFiled: August 25, 1997Date of Patent: April 20, 1999Assignee: Hatco CorporationInventors: Michael A. McHenry, Dale D. Carr, Thomas G. Schaefer
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Patent number: 5792383Abstract: Fluid refrigeration compositions comprising a hydrocarbon lubricant, an immiscible refrigerant and an additive capable of reducing the interfacial tension between the hydrocarbon lubricant and refrigerant.Type: GrantFiled: September 7, 1994Date of Patent: August 11, 1998Assignee: Witco CorporationInventors: Jose L. Reyes-Gavilan, Alan D. Eckard, G. Thomas Flak, Todd R. Tritcak, Leonard Aconsky
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Patent number: 5750750Abstract: A complex alcohol ester which comprises the reaction product of an add mixture of the following: a polyhydroxyl compound represented by the general formula:R(OH).sub.nwherein R is any aliphatic or cyclo-aliphatic hydrocarbyl group and n is at least 2, provided that the hydrocarbyl group contains from about 2 to 20 carbon atoms; a polybasic acid or an anhydride of a polybasic acid, provided that the ratio of equivalents of the polybasic acid to equivalents of alcohol from the polyhydroxyl compound is in the range between about 1.6:1 to 2:1; and a monohydric alcohol, provided that the ratio of equivalents of the monohydric alcohol to equivalents of the polybasic acid is in the range between about 0.84:1 to 1.2:1; wherein the complex alcohol ester exhibits a pour point of less than or equal to -20.degree. C., a viscosity in the range between about 100-700 cSt at 40.degree. C. and having a polybasic acid ester concentration of less than or equal to 70 wt. %, based on the complex alcohol ester.Type: GrantFiled: February 7, 1997Date of Patent: May 12, 1998Assignee: Exxon Chemical Patents Inc.Inventors: Carolyn Boggus Duncan, Paul R. Geissler, David Wayne Turner, William Joseph Munley, Jr., Martin A. Krevalis
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Patent number: 5744434Abstract: A synthetic ester composition which exhibits thermal and oxidative stability, lower friction coefficient and lower wear, wherein the ester composition comprises the reaction product of: a branched or linear alcohol having the general formula R(OH).sub.n, wherein R is an aliphatic or cyclo-aliphatic group having from about 2 to 20 carbon atoms and n is at least 2; and at least one branched mono-carboxylic acid which has a carbon number in the range between about C.sub.5 to C.sub.13 ; wherein the synthetic ester composition has between about 5-35% unconverted hydroxyl groups, based on the total amount of hydroxyl groups in the branched or linear alcohol.Type: GrantFiled: March 14, 1996Date of Patent: April 28, 1998Assignee: Exxon Chemical Patents Inc.Inventors: Richard Henry Schlosberg, Haven S. Aldrich, Lavonde Denise Sherwood-Williams, John S. Szobota, Martin Anthony Krevalis, Daniel P. Leta, David Gary Lawton Holt, Fay H. Gordon
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Patent number: 5681506Abstract: A corrosion inhibiting lubricating composition comprises:(a) a synthetic ester base stock;(b) at least one aromatic amine antioxidant;(c) a neutral organic phosphate of the formula (R.sup.1 O).sub.3 PO where R.sup.1 is a tolyl, phenyl, xylyl, alkyl or cycloalkyl group, the alkyl or cycloalkyl group having up to 10 carbon atoms;(d) a saturated or unsaturated dicarboxylic acid of the general formula ##STR1## wherein x+y+z is an integer in the range from 2 to 22 inclusive and where at least one of the groups R.sub.1 to R.sub.5 is a carboxylic acid group; or a dicarboxylic acid of one of the three formulae ##STR2## (e) a straight or branched chain saturated or unsaturated monocarboxylic acid which is optionally sulphurised or an ester of such an acid; and(f) a triazole of the formula: ##STR3## or a triazole selected from 1,2,4 triazole, 1,2,3 triazole, 5-anilo-1,2,3,4-thiatriazole, 3-amino-1,2,4 triazole, 1-H-benzotriazole-1-yl-methylisocyanide, methylene-bis-benzotriazole and naphthotriazole.Type: GrantFiled: May 9, 1994Date of Patent: October 28, 1997Assignee: Castrol LimitedInventors: John William Anthony Pragnell, Andrew Jonathan Markson, Mark Anthony Edwards
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Patent number: 5674822Abstract: A low emissions, high oxidative stability crankcase lubricating oil formulation which is prepared from a base stock which comprises at least one synthetic ester selected from the group consisting of: polyol esters, synthetic esters having between 5-35% unconverted hydroxyl groups, based on the total amount of hydroxyl groups in the polyol, and synthetic esters combined with at least one additional functional group which is capable of increasing the polarity of the functionalized synthetic ester, wherein the base stock has an oxygen, nitrogen or halogen content of at least 15 wt. %, based on the total weight of the base stock; and a lubricant additive package.Type: GrantFiled: September 21, 1995Date of Patent: October 7, 1997Assignee: Exxon Chemical Patents IncInventors: Richard Henry Schlosberg, Walter Weissman, Maciej Radosz, Gerald Dennis Dupre', Ralph Donald Gray, Jr., John Eric Johnston, Patrick Edward Godici, Richard Samuel Polizzotti, Lawrence Harold Kaplan
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Patent number: 5665686Abstract: A synthetic ester composition exhibiting thermal and oxidative stability which comprises the reaction product of: a branched or linear alcohol having the general formula K(OH).sub.n, wherein R is an aliphatic or cyclo-aliphatic group having from about 2 to 20 carbon atoms and n is at least 2; and at least one branched mono-carboxylic acid which has a carbon number in the range between about C.sub.5 to C.sub.13 ; wherein the synthetic ester composition has between 5-35% unconverted hydroxyl groups, based on the total amount of hydroxyl groups in the branched or linear alcohol.Type: GrantFiled: March 14, 1995Date of Patent: September 9, 1997Assignee: Exxon Chemical Patents Inc.Inventors: Richard Henry Schlosberg, Lavonda Denise Sherwood-Williams, Haven S. Aldrich, John S. Szobota
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Patent number: 5620950Abstract: The objective of the present invention resides in providing a lubricant for refrigerators that reacts rapidly with free acids and contains a stabilizer that has good compatibility with a chlorine-free Flon-thpe coolant such as Flon 134a and the like whose molecules do not contain chlorine. The lubricant for refrigerators employing a chlorine-free Flon-type coolant in accordance with the present invention 100 parts by weight of a synthetic oil and is compounded with 0.05 to 15 parts by weight of an alicyclic epoxy compound having one or more functional groups represented by the following formula: ##STR1## (wherein R.sub.1 and R.sub.2 independently represent a hydrogen or methyl group, and may be the same or different).Type: GrantFiled: August 8, 1995Date of Patent: April 15, 1997Assignee: Asahi Denka Kogyo K.K.Inventors: Tamiji Kamakura, Noriyoshi Tanaka, Kimiyoshi Namiwa, Yukio Tatsumi, Masato Namiki