AU2007280548A1

AU2007280548A1 - Lubricant composition

Info

Publication number: AU2007280548A1
Application number: AU2007280548A
Authority: AU
Inventors: David Eliezer Chasan; Marc Ribeaud; Patricia Roberta Wilson
Original assignee: Ciba Holding AG
Current assignee: BASF SE
Priority date: 2006-07-31
Filing date: 2007-07-23
Publication date: 2008-02-07
Anticipated expiration: 2027-07-23
Also published as: KR101433140B1; JP2009545640A; WO2008015116A2; IL196250A0; CA2657382C; JP2014139313A; CN101495605B; AU2007280548B2; CN101495605A; BRPI0714961A2; MX2009001124A; RU2462505C2; KR20090033358A; PL2049630T3; WO2008015116A3; IL196250A; BRPI0714961B1; RU2009106723A; EP2049630A2; CA2657382A1

Description

WO 2008/015116 PCT/EP2007/057552 Lubricant Composition The present invention relates to lubricant compositions stabilized against oxidative degrada tion via the incorporation of certain sterically hindered amine stabilizers. The lubricant com positions exhibit excellent results regarding seal swell. 5 U.S. Pat. Nos. 5,073,278 and 5,273,669 teach the stabilization of lubricant compositions with a certain aromatic amine and at least one sterically hindered amine. U.S. Pat. No. 5,268,113 discloses lubricants stabilized by the addition of a sterically hindered amine and a phenol. It is known to add stabilizers to lubricants based on mineral or synthetic oils in order to im 10 prove their performance characteristics. Antioxidants are of particular importance. Oxidative degradation of lubricants plays a significant role especially in motor oils because of the high temperatures prevailing in the combustion chambers of the engines and the presence, in ad dition to oxygen, of oxides of nitrogen which act as oxidation catalysts. Hindered amine compounds are effective stabilizers for lubricants. However, they are gener 15 ally not employed due to detrimental effects such as seal swell. The present invention relates to the stabilization of lubricant compositions with a specific class of hindered amine compounds. The present lubricant compositions are non-aggressive towards seals. The present invention relates to a stabilized lubricant composition which comprises 20 A mineral or a synthetic base oil or a mixture of a mineral and a synthetic base oil; and At least one sterically hindered amine compound of the formula 0 HN O R () or 0 0 HN o (CH 2 )n 0 NH (Il) WO 2008/015116 PCT/EP2007/057552 -2 where R is a straight or branched alkyl group of from 7 to 17 carbon atoms and n is a nu meral from 6 to 18. The alkyl group R is linear or branched and consist of for example 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or 17 carbons. 5 The numeral n is for example 6, 8, 10, 12, 14, 16 or 18. The sterically hindered amines are known and are prepared according to methods known in the art. For example, the present hindered amines are 2,2,6,6-tetramethylpiperidin-4-o es ters of aliphatic carboxylic acids, for example the esters of lauric acid or stearic acid. According to a preferred embodiment, the invention relates to compositions wherein the hin 10 dered amines of the formula 0 HN O C1H2 or O O HN 0 (CH 2

)

8 0 NH are present. Lubricants according to the present invention are functional fluids, that is lubricants, hydraulic 15 fluids or metal working fluids. Lubricants are in particular mineral oil based (API classifications Groups 1, 11, 111, Group IV in cluding gas to liquid (GTL) oils) or synthetic base oils, such as is normally used for the pro duction of lubricants. Synthetic oils may be, for example, esters of polycarboxylic acids or of polyols; they may also be aliphatic polyesters or poly-a-olefins, silicones, phosphoric acid 20 esters or polalkylene glycols. The lubricant may also be a grease based on an oil and a thickener. Such lubricants are described, for example in D. Klamann "Schmierstoffe und art verwandte Producte", Verlag Chemie, Weinheim, 1982. Examples are lubricants and hydraulic fluids based on mineral oil or synthetic lubricants or hydraulic fluids, in particular those which are derivatives of carboxylic esters and which are 25 used at temperatures of 200'C and above.

WO 2008/015116 PCT/EP2007/057552 -3 Examples of synthetic lubricants embrace lubricants based on a diester of a dibasic acid with a monovalent alcohol, for example dioctyl sebacate or dinonyl adipate, a triester of trimethy lolpropane with a monobasic acid or a mixture of such acids, for example trimethylolpropane tripelargonate, trimethylolpropane tricaprylate or mixtures of these, a tetraester of pentae 5 rythritol with a monobasic acid or with a mixture of such acids, for example pentaerythritol tetracaprylate, or a complex ester of monobasic and dibasic acids with polyhydric alcohols, for example a complex ester of trimethylolpropane with caprylic and sebacic acid or a mixture of these. Particularly suitable are, besides mineral oils, for example poly-a-olefins, lubricants based on 10 esters, or phosphates, glycols, polyglycols and polalkyene glycols and mixtures of these with water. The sterically hindered amines of this invention are in particular non-aggressive toward elastomeric seals. The seals are in particular a fluoropolymer elastomer used in O-rings and other goods. The 15 "fluoroelastomers" are categorized under ASTM D1418 and ISO 1629 designation of FKM for example. The fluoroelastomers comprise copolymers of hexafluoropropylene (HFP) and vi nylidene fluoride (VDF of VF2), terpolymers of tetrafluoroethylene (TFE), vinylidene fluoride and hexafluoropropylene, perfluoromethylvinylether (PMVE), copolymers of TFE and propyl ene and copolymers of TFE, PMVE and ethylene. The fluorine content varies for example 20 between about 66 to about 70% by weight. FKM is fluoro rubber of the polymethylene type having substituent fluoro and perflouroalkyl or perfluoroalkoxy groups on the polymer chain. Accordingly, a preferred subject of the invention is a stabilized lubricant composition which is in contact with a fluoroelastomer and which comprises 25 A mineral or a synthetic base oil or a mixture of a mineral and a synthetic base oil and At least one sterically hindered amine compounds of the formula (1) or (II), where R is a straight or branched alkyl group of from 7 to 17 carbon atoms and n is a nu meral from 6 to 18. The sterically hindered amines according to this invention are admixed with the lubricants in 30 an amount of about 0.01 to about 5% by weight, for example from about 0.05 to about 3% by weight, for instance from about 0.1 to about 2% by weight, based on the weight of the lubri cant.

WO 2008/015116 PCT/EP2007/057552 -4 The lubricants can additionally comprise other additives which are added to improve the ba sic properties of lubricants even further; these include antioxidants, metal passivators, rust inhibitors, viscosity index improvers, pour point depressors, dispersants, detergents, high pressure additives, antifriction additives and antiwear additives. 5 These additional additives are for example: 1. Antioxidants 1.1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl -4,6 dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2-(a-methylcyclohexyl)-4,6-dimeth 10 ylphenol, 2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-meth oxymethylphenol, 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl -6(1'-methylundec-1'-yl)phenol, 2,4-dimethyl-6-(1'-methylheptadec-1'-yl)phenol, 2,4-dimethyl-6-(1'-methyltridec-1'-yl)phenol and mixtures thereof. 1.2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioc 15 tylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-didodecylthiomethyl-4 nonylphenol. 1.3. Hydroquinones and alkylated hydroquinones, for example 2,6-di-tert-butyl-4-methoxy phenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octade cyloxyphenol, 2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert 20 butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenyl stearate, bis-(3,5-di-tert-butyl-4-hy droxyphenyl) adipate. 1.4. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis(6-tert-butyl-4-methylphenol), 2,2'-thiobis(4-octylphenol), 4,4'-thiobis(6-tert-butyl-3-methylphenol), 4,4'-thiobis(6-tert-butyl-2 methylphenol), 4,4'-thiobis-(3,6-di-sec-amylphenol), 4,4'-bis-(2,6-dimethyl-4-hydroxyphenyl) 25 disulfide. 1.5. Alkylidenebisphenols, for example 2,2'-methylenebis(6-tert-butyl-4-methyphenol), 2,2' methylenebis(6-tert-butyl-4-ethylphenol), 2,2'-methylenebis[4-methyl-6-(a-methylcyclo hexyl)phenol], 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(6-nonyl-4 methylphenol), 2,2'-methylenebis(4,6-di-tert-butylphenol), 2,2'-ethylidenebis (4,6-di-tert-butyl 30 phenol), 2,2'-ethylidenebis(6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis [6-(a-methylben zyl)-4-nonylphenol], 2,2'-methylenebis[6-(a,a-dimethylbenzyl) -4-nonylphenol], 4,4'-methyle nebis(2,6-di-tert-butylphenol), 4,4'-methylenebis(6-tert-butyl-2-methylphenol), 1,1 -bis(5-tert butyl-4-hydr oxy-2-methylphenyl)butane, 2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4 methylphenol, 1,1,3-tris(5-tert-butyl-4-hydroxy -2-methylphenyl)butane, 1,1 -bis(5-tert-butyl-4 35 hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane, ethylene glycol bis[3,3-bis(3'-tert-bu- WO 2008/015116 PCT/EP2007/057552 -5 tyl-4'-hydroxyphenyl)butyrate], bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene, bis[2-(3'-tert-butyl -2'-hydroxy-5'-methylbenzyl) -6-tert-butyl-4-methylphenyl]terephthalate, 1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane, 2,2-bis-( 3,5-di-tert-butyl-4-hydroxy phenyl)propane, 2,2-bis-(5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane, 5 1,1,5,5-tetra-(5-tert -butyl-4-hydroxy2-methylphenyl)pentane. 1.6. 0-, N- and S-benzyl compounds, for example 3,5,3',5'-tetra-tert-butyl-4,4'-dihydroxy dibenzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate, tris-(3,5-di-tert -bu tyl-4-hydroxybenzyl)amine, bis(4-tert-butyl-3-hyd roxy-2,6-di methyl benzyl)d ithioterephthalate, bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, isooctyl-3,5di-tert-butyl-4-hydroxybenzylmer 10 captoacetate. 1.7. Hydroxybenzylated malonates, for example dioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hy droxybenzyl)-malonate, d i-octadecyl-2-(3-tert-butyl-4-hyd roxy-5-methylbenzyl)-malonate, di dodecylmercaptoethyl-2,2-bis-(3,5-di-tert-butyl-4-hydroxybenzyl)malonat e, bis [4-(1,1,3,3 tetramethylbutyl)phenyl]-2,2-bis(3,5-d i-tert-butyl-4-hyd roxybe nzyl)malonate. 15 1.8. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris-(3,5-di-tert-butyl-4-hydroxy benzyl)-2,4,6-trimethylbenzene, 1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetrame thylbenzene, 2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol. 1.9. Triazine Compounds, for example 2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hy droxyanilino)-1,3,5-triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino) -1,3,5 20 triazine, 2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy) -1,3,5-triazine, 2,4,6 tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxy benzyl)isocyanu rate, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl 2,4,6-tris(3,5-di-tert butyl-4-hydroxyphenylethyl)-1,3,5-triazine, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropio nyl)-hexahydro-1,3,5-triazine, 1,3,5-tris(3,5-d icyclohexyl-4-hyd roxybenzyl)isocyan urate. 25 1.10. Benzylphosphonates, for example dimethyl-2,5-di-tert-butyl-4-hydroxybenzylphospho nate, diethyl-3,5-d i-tert-butyl-4-hyd roxybenzylphosphonate, dioctadecyl3,5-di-tert-butyl -4 hydroxybenzylphosphonate, dioctadecyl-5-tert-butyl-4-hydroxy3-methylbenzylphosphonate, the calcium salt of the monoethyl ester of 3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid. 1.11. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N 30 (3,5-d i-tert-butyl-4-hyd roxyphenyl)carbamate. 1.12. Esters of [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thi 35 aundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl 1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane.

WO 2008/015116 PCT/EP2007/057552 -6 1.13. Esters of p-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid with mono- or polyhy dric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, eth ylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N' 5 bis(hydroxyethyl)oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hyd roxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. 1.14 Esters of 13-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene 10 glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thi aundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl 1 -phospha-2,6,7-trioxabicyclo[2.2.2]octane. 1.15 Esters of 3,5-di-tert-butyl-4-hydroxypheny acetic acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 15 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris(hydroxyethyl) isocyanurate, N,N'-bis(hydroxyethyl)oxamide, 3-thiaunde canol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1 phospha-2,6,7-trioxabicyclo[2.2.2]octane. 1.16. Amides of p-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g. N,N'-bis(3,5-di-tert 20 butyl-4-hydroxyphenylpropionyl)hexamethylenediamine, N,N'-bis(3,5-di-tert-butyl -4-hydroxy phenylpropionyl)trimethylenediamine, N,N'-bis(3,5-di-tert-butyl-4-hydroxyphenylpropio nyl)hydrazine. Aminic antioxidants: N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, N,N'-bis (1,4 25 dimethylpentyl)-p-phenylenediamine, N,N'-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-dicyclohexyl-p-phenylenediamine, N,N' diphenyl-p-phenylenediamine, N,N'-bis(2-naphthyl)-p-phenylenediamine, N-isopropyl-N' phenyl-p-phenylenediamine, N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine, N-(1 methylheptyl)-N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-p-phenylenediamine, 30 4-(p-toluenesulfamoyl)diphenylamine, N,N'-dimethyl-N,N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyldiphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthyl amine, N-phenyl-2-naphthylamine, octylated diphenylamine, for example p,p'-di-tert-octyldi phenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-do decanoylaminophenol, 4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine, 2,6-di-tert 35 butyl-4-dimethylaminomethylphenol, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl methane, N,N,N',N'-tetramethyl -4,4'-diaminodiphenylmethane, 1,2-bis[(2-methyl- WO 2008/015116 PCT/EP2007/057552 -7 phenyl)amino]ethane, 1,2-bis(phenylamino)propane, (o-tolyl)biguanide, bis[4-(1',3'-dimethyl butyl)phenyl]amine, tert-octylated N-phenyl-1-naphthylamine, a mixture of mono- and dialky lated tert-butyl/tert-octyldiphenylamines, a mixture of mono- and dialkylated isopro pyl/isohexyldiphenylamines, mixtures of mono- and dialkylated tert-butyldiphenylamines, 2,3 5 dihydro-3,3-dimethyl -4H-1,4-benzothiazine, phenothiazine, N-allylphenothiazine, N,N,N',N' tetraphenyl -1,4-diaminobut-2-ene, N,N-bis(2,2,6,6-tetramethylpiperid-4-yl-hexamethyl enediamine, bis(2,2,6,6 -tetramethylpiperid-4-yl)sebacate, 2,2,6,6-tetramethylpiperidin-4-one and 2,2,6,6-tetramethylpiperidin-4-ol. Examples of other antioxidants: 10 Aliphatic or aromatic phosphites, esters of thiodipropionic acid or of thiodiacetic acid, or salts of dithiocarbamic or dithiophosphoric acid, 2,2,12,12-tetramethyl-5,9-dihydroxy -3,7,11 trithiatridecane and 2,2,15,15- tetramethyl-5,1 2-dihydroxy-3,7,10,1 4-tetrathiahexadecane. Examples of metal deactivators, for example for copper, are: a) Benzotriazoles and derivatives thereof, for example 4- or 5-alkylbenzotriazoles (e.g. tolu 15 triazole) and derivatives thereof, 4,5,6,7-tetrahydrobenzotriazole and 5,5'-methylenebisben zotriazole; Mannich bases of benzotriazole or tolutriazole, e.g. 1-[bis(2-ethyl hexyl)aminomethyl)tolutriazole and 1 -[bis(2-ethylhexyl)aminomethyl)benzotriazole; and alkoxyalkylbenzotriazoles such as 1-(nonyloxymethyl)benzotriazole, 1-(1 -bu toxyethyl)benzotriazole and 1 -(1 -cyclohexyloxybutyl)tolutriazole. 20 b) 1,2,4-Triazoles and derivatives thereof, for example 3-alkyl(or aryl)-1,2,4-triazoles, and Mannich bases of 1,2,4-triazoles, such as 1-[bis(2-ethylhexyl)aminomethyl -1,2,4-triazole; alkoxyalkyl-1,2,4-triazoles such as 1-(1-butoxyethyl)-1,2,4-triazole; and acylated 3-amino 1,2,4-triazoles. c) Imidazole derivatives, for example 4,4'-methylenebis(2-undecyl-5-methylimidazole) and 25 bis[(N-methyl)imidazol-2-yl]carbinol octyl ether. d) Sulfur-containing heterocyclic compounds, for example 2-mercaptobenzothiazole, 2,5 dimercapto-1,3,4-thiadiazole and derivatives thereof; and 3,5-bis[di(2-ethyl hexyl)aminomethyl]-1,3,4-thiadiazolin-2-one. e) Amino compounds, for example salicylidenepropylenediamine, salicylaminoguanidine and 30 salts thereof. Examples of rust inhibitors and friction modifiers are: a) Organic acids, their esters, metal salts, amine salts and anhydrides, for example alkyl- and alkenylsuccinic acids and their partial esters with alcohols, diols or hydroxycarboxylic acids, partial amides of alkyl- and alkenylsuccinic acids, 4-nonylphenoxyacetic acid, alkoxy- and 35 alkoxyethoxycarboxylic acids such as dodecyloxyacetic acid, dodecyloxy(ethoxy)acetic acid and the amine salts thereof, and also N-oleoylsarcosine, sorbitan monooleate, lead WO 2008/015116 PCT/EP2007/057552 -8 naphthenate, alkenylsuccinic anhydrides, for example dodecenylsuccinic anhydride, 2-car boxymethyl-1-dodecyl-3-methylglycerol and the amine salts thereof. b) Nitrogen-containing compounds, for example: 1. Primary, secondary or tertiary aliphatic or cycloaliphatic amines and amine salts of organic 5 and inorganic acids, for example oil-soluble alkylammonium carboxylates, and also 1-[N,N bis(2-hydroxyethyl)amino]-3-(4-nonylphenoxy)propan-2-ol. II. Heterocyclic compounds, for example: substituted imidazolines and oxazolines, and 2 heptadecenyl-1 -(2-hydroxyethyl)imidazoline. c) Phosphorus-containing compounds, for example: Amine salts of phosphoric acid partial 10 esters or phosphonic acid partial esters, and zinc dialkyldithiophosphates. d] Molybdenum- containing compounds, such as Molydbenum dithiocarbamate and other sulphur and phosphorus containing derivatives e) Sulfur-containing compounds, for example: barium dinonylnaphthalenesulfonates, calcium petroleum sulfonates, alkylthio-substituted aliphatic carboxylic acids, esters of aliphatic 2 15 sulfocarboxylic acids and salts thereof. f) Glycerol derivatives, for example: glycerol monooleate, 1-(alkylphenoxy)-3-(2-hy droxyethyl)glycerols, 1 -(alkylphenoxy)-3-(2,3-dihydroxypropyl)glycerols and 2-carboxyalkyl 1,3-dialkylglycerols. Examples of viscosity index improvers are: 20 Polyacrylates, polymethacrylates, vinyl pyrrolidone/methacrylate copolymers, polyvinylpyrroli dones, polybutenes, olefin copolymers, styrene/acrylate copolymers and polyethers. Examples of pour-point depressants are: Polymethacrylate and alkylated naphthalene derivatives. Examples of dispersants/surfactants are: 25 Polybutenylsuccinic amides or -imides, polybutenylphosphonic acid derivatives and basic magnesium, calcium and barium sulfonates and phenolates. Examples of antiwear additives are: Sulfur- and/or phosphorus- and/or halogen-containing compounds, e.g. sulfurised olefins and vegetable oils, zinc dialkyldithiophosphates, alkylated triphenyl phosphates, tritolyl phos 30 phate, tricresyl phosphate, chlorinated paraffins, alkyl and aryl di- and trisulfides, amine salts of mono- and dialkyl phosphates, amine salts of methylphosphonic acid, diethanolami nomethyltolyltriazole, bis(2-ethylhexyl)aminomethyltolyltriazole, derivatives of 2,5-dimer capto-1,3,4-thiadiazole, ethyl 3-[(diisopropoxyphosphinothioyl)thio]propionate, triphenyl thio phosphate (triphenylphosphorothioate), tris(alkylphenyl) phosphorothioate and mixtures 35 thereof (for example tris(isononylphenyl) phosphorothioate), diphenyl monononylphenyl phosphorothioate, isobutylphenyl diphenyl phosphorothioate, the dodecylamine salt of 3-hy- WO 2008/015116 PCT/EP2007/057552 -9 droxy-1,3-thiaphosphetane 3-oxide, trithiophosphoric acid 5,5,5-tris[isooctyl 2-acetate], de rivatives of 2-mercaptobenzothiazole such as 1-[N,N-bis (2-ethylhexyl)aminomethyl]-2-mer capto-1 H-1,3-benzothiazole, and ethoxycarbonyl-5-octyldithiocarbamate. The examples which follow illustrate the invention in greater detail. Parts and percentages 5 are by weight, unless otherwise indicated. Example The superiority of the claimed sterically hindered amines over other similar sterically hin dered amine additives is illustrated by the following example. A 5W-30 engine oil containing 0.08 %P is supplemented with sufficient sterically hindered amine additive to raise the total 10 base number, as measured by ASTM D 4739 by two units. Amine additive A is added at a treat level of 1.0 weight percent and amine additive B is added at a treat level of 1.2%. The oils are stirred at 600C for one hour to insure homogeneity. The formulations are tested ac cording to elastomer compatibility procedure CEC- L-39-T-96. The results of the CEC- L-39 T-96 testing of these formulations with an FKM fluorinated rubber are found below. Both 15 amines affected the rubber elastomer. 1 2 3 Material wt% wt% wt% Base formulation 100 99.0 98.8 Amine A 0 1.0 0 Amine B 0 0 1.2 Results FKM rubber ACEA Spec Hardness [DIDC, points] -1 3 0 -1/+5 Tensile strength [%] -17 -51 -33 -40/+10 Elongation at rupture [%] -29 -75 -55 -5-/+10 Volume variation [%] 0.7 1.1 1.1 -1/+5 The magnitude of the effect of amine A on tensile strength and elongation at rupture made it totally unsuitable for use relative to specifications such as that of ACEA. Amine B has much 20 less of an effect on the fluorinated rubber - indicating it is suitable for use in engine oils.

WO 2008/015116 PCT/EP2007/057552 -10 0 0 Amine A is H 3 C-N 0 (CH2)e O N-CH 3 0 Amine B is HN O C1 H23

Claims

1. A stabilized lubricant composition which comprises A mineral or a synthetic base oil or a mixture of a mineral and a synthetic base oil and At least one sterically hindered amine compounds of the formula 0 HN O R 5 or 0 0 HN 0 (CH 2 )n 0 NH (II) where R is a straight or branched alkyl group of from 7 to 17 carbon atoms and n is a numeral from 6 to 18.

2. A composition according to claim 1 where R is a straight or branched alkyl group of 10 11 or 17 carbon atoms and n is a numeral from 6 or 8.

3. A compositon according to claim 1 where the hindered amine is of the formula (1).

4. A composition according to claim 1 where the hindered amine is of the formula (II).

5. A composition according to claim 1 where the hindered amine is of the formula 0 HN O C1H2 15

6. A stabilized lubricant composition according to claim 1 where the hindered amine is of the formula WO 2008/015116 PCT/EP2007/057552 -12 O O HN o (CH 2 ) 8 0 NH

7. A composition according to claim 1 where the hindered amine is present from about 0.01 to about 5% by weight, based on the weight of the lubricant.

8. A composition according to claim 1 where the hindered amine is present from about 5 0.05 to about 3% by weight, based on the weight of the lubricant.

9. A composition according to claim 1 where the hindered amine is present from about 0.1 to about 2% by weight, based on the weight of the lubricant.

10. A stabilized lubricant composition which is in contact with a fluoroelastomer and which comprises 10 At least one mineral or a synthetic base oil or a mixture of a mineral and a synthetic base oil and At least one or more sterically hindered amine compounds of the formula (1) or (II), where R is a straight or branched alkyl group of from 7 to 17 carbon atoms and n is a numeral from 6 to 18. 15