AU680553B2 - Mixed antioxidant composition - Google Patents

Description

WO 95/07963 PCT/EP94/03064 Mixed Antioxidant Composition This invention relates to lubricating oil additives, and to lubricating oil compositions and concentrates prepared therefrom. More specifically it relates to an additive containing a combination of a molybdenum compound and an aromatic amine compound as an antioxidant.

Lubricating oils as used in, for example, the internal combustion engines of automobiles or trucks are subjected to a demanding environment during use.

This environment results in the oil suffering oxidation which is catalysed by the presence of impurity species in the oil such as iron compounds and is also promoted by the elevated temperatures experienced by the oil during use. This catalysed oxidation of the oil contributes to the formation of corrosive oxidation products and sludge in the oil but can also cause the viscosity of the oil to increase or even cause the oil to solidify. This oxidation of lubricating oils during use is usually controlled to some extent by the use of antioxidant additives which may extend the useful life of the oil particularly by reducing or preventing unacceptable viscosity increases.

There is, however, a continuing need for new antioxidants and antioxidant systems which offer improved performance and which are effective at low levels.

There are a number of factors which have contributed to this continuing need.

One such factor is that in recent years internal combustion engines are often operated at higher temperatures which tends to increase the rate of oxidation and so shorten the useful life of the oil. In addition there is a strong desire to use cheaper base stocks for lubricating oil compositions which have inferior resistance to oxidation and require more efficient and effective antioxidants.

Thero is also a need for lubricating oils to have a longer in service life span due to the service intervals for motor vehicles becoming longer. There is also a desire to find antioxidants and antioxidant systems which meet the above requirements and at the same time are not detrimental to other aspects of motor vehicle performance. In this respect there is a desire for antioxidants which do not contribute to the phosphorus content of motor vehicle exhausts as as phosphorus is detrimental to the performance of catalyst based exhaust purification systems. In addition some antioxidants such as for example diphonylamines cannot be used at relatively high concentrations as this may SUtJIflTUTE SHUTr (N'TLE -Il i i i-iY~ L-l result in sedimentation or deposits in hot engine areas such as the diesel ring areas in diesel engines. The invention is concerned with the problem of providing an improved antioxidant for use in lubricating oils.

We have now discovered that a combination of certain molybdenum containing compounds and certain aromatic amines is a highly effective regenerative antioxidant system for use in lubricating oils and especially in lubricating oils for gasoline and diesel engines.

There have been a number of proposals for the use of molybdenum compounds as antioxidants for lubricating oils such as those described in US 3 356 702, US 4 098 705, US 4 265 773, US 4 285 882, US 4 369 119, US 4 370 246, US 4 394 279, US 4 846 983 and EP 0 205 165. Both US 4 370 246 and US 4 394 279 describe the use of combinations of specific molybdenum compounds with aromatic amines wherein the molybdenum compounds are prepared from the reaction of an acidic molybdenum compound with a basic nitrogen compound selected from either Mannich bases phosphonamides, thiophosphonamide, phosphoramide, succinamide, carboxylic acid amide, dispersant viscosity index improvers or mixtures thereof and either carbon disulfide or other sulphur containing compounds.

US 4 479 883 is concernrd with the provision of lubricant compositions with improved friction reducing properties containing a mixture of dithiocarbamates.

EPO 447 916 Ai is concerned with engine oil compositions which exhibit fuel saving effects. The compositions are based on the combination of an ovorbasic oil-soluble metal salt in combination with a friction modifier and an antioxidant.

GB 1 097 372 describes a synthesis for molybdenum dialkyldithiocarbamates and there use in lubricants.

JP 61080825 describes the synthesis of molybdenum additives from molybdenum trisulphide secondary amine and carbon disulphide. The synthesis allows high purity product to be prepared in high yield and in one step.

U~IIIIYI 1 According to the present invention there is provided a lubricating oil additive which comprises a combination of an oil-soluble molybdenum containing compound of general formula I: R2 S S R 3 N e Me QCN R N- "Io" C-N R1 X SXl S "R4 I wherein R 1

R

2

R

3 and R 4 may be the same or different and each independently represent a C7 to C24 hydrocarbyl radical, X and X1 may be the same or different and independently represent S or 0, and the Mo is in oxidation state five or less; and at least one oil-soluble aromatic amine.

By the term hydrocarbyl radical is meant an organic moiety which comprises hydrogen and carbon and which unless the context states otherwise may be aiiphatic (including alicyclic), aromatic or a combination thereof. It may be substituted or unsubstituted, alkyl, aryl or alkaryl and may optionally contain unsaturation or heteroatoms such as 0, N or S. It is preferred that the hydrocarbyl radical does not contain heteroatom substitution, It is preferred that the hydrocarbyl radical is a hydrocarbyl radical of 01O to 018 and most preferably is a C1 2 or Ci 3 aliphatic hydrocarbyl radical. Examples of suitable aliphatic hydrocarbyl radicals include, 2"ethyihexyl, nonyiphenyl, dodecyl, pentyl, cyclohexyl, phenylmethyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, or t-butyl. The choice of R 1

R

2

R

3 and R 4 must be such that the resulting molybdenum compound of general structure I is oil-soluble.

It is preferred that X and X 1 are the same. It is most preferred that X and X1 are S.

By the term aromatic amine is meant any secondary amine with at least one aromatic group; such an amnine gives a synergistic antioxidant effect when used In combination with a molybdenum compound of general formula I.

It Is preferred that the oil-soluble secondary aromatic amines are diphenylamines of general formula It:

H

(R

6

)B

wherein RS and q 6 may be the same or different and each independently represents a hydrocarbyl radical as hereinibefore defined. It is preferred that R$ and R 6 are 01, tQ 028 aliphatic hydrocarbyl radicals. A and B may be the same or diffrent and may equal 0, 1, 2 or 3. It is preferred that A and 0 are the same and that they equal 1. It Is also preferred that the diphenyfamines have a nitrogent content ot between and 5%X by weight. It Is preferred that R6 and R 6 aire located In the meta or para positiois relative to the amino substitution In the aromatio rings of the diphanylamines. 5xamploo of suitable diphenylarnines Include di-actyldiphenylamine, t..pentyldiphenylamino, diisobornyldiphenylamino, didecyldlphanylamine, didodooyidiphenylamine, dihoxyldiphonylamnine, dinoriylamine, dibutyldiphenylamine, WO 95/07963 PCT/EP94/03064 -4distyryldiphenylamine. Other suitable diphenylamines include di-substituted derivatives wherein the R 5 and R 6 are different and independently represent hydrocarbyl radicals such as for example t-butyl, t-octyl, styryl, n-butyl or n-octyl.

Some of these diphenylamines are commercially available and are sold under the trademarks, Vanlube DND, Naugalube 438L, Pearsall OA502, Lubrizol 5150A, Vanlube SL, Naugalube 680, Inganox L-57 and Vanlube 848. Vanlube DND, Naugalube 438L, Pearsall OA502 and Lubrizol 5150A nominally have structures as represented by general formula II wherein R 5 and R 6 are C9 hydrocarbyl groups and A=B=1, Vanlube SL and Naugalube 680 nominally have structures as represented by general formula 1I wherein R 5 and R 6 are either one of C4, C8 or styryl hydrocarbyl groups and A1B=l; these are mixed diphenyl amines. Irganox L-57 and Vanlube 848 nominally have structures as represented by general formula II wherein R 5 and R 6 are either one of t-butyl or t-octyl groups and A=B=1.

Some of the oil-soluble molybdenum compounds of Formula I are commercially available. For example products where X and X 1 are 0 and where R 1

R

2

R

3 and R 4 are C13H27 aliphatic hydrocarbyl groups and where the molybdenum is in oxidation state V are sold under the trademarks Molyvan 807 and Molyvan 4o 822 as antiox:Jants and friction reducing additives by R.T. Vanderbilt Company Inc. Norwalk CT USA. These molybdenum compounds may be prepared by the methods described in US 3 356 72 wherein MoO3 is converted to solutie molybdate by dissolving in alkali metal hydroxide solution, neutralised by the addition of acid followed by the addition of a secondary amino and carbon disulfide.

The molybdenum compounds of general structure I wherein X and Xl are S may be prepared by a number of methods. JP 51080825 (Asahi Denka Kogyo K.K.) discloses a method wherein MoS3, secondary amine and CS2 are reacted together in an inert organic solvent. Bull. Jap. Petrol. Inst. 1971, 13(2), 243-9 discloses a method wherein sulfurized molybdenum dialkyl dithiocarbamates prepared according to US 3356 702 are treated in xylene solution with P2S$ with heating followed by the dissolving in DMF of the resulting precipitate with further heating. J.Am.ChemSoc., Vol 102, No. 15 1980, 5102-4 discloses a method wherein polynuctear molybdenum complexes of structure lit SB;IB~~~B& (ff~tE 1Sr~i 'W MWA WO 95107963 PCT/EP94/03064 S2,, M S2. M s2 s2 Mo, s Mo 1S2

S

2 2 iii prepared by the method disclosed in Angew. Chem., Int. Ed. Engl., 7, 279 (1978), are refluxed in CH3OH with 20 equivalents of Na($2CN(C2H5)2) for two hours.

6 Although it Is not understood how the molybdenum compounds of general structure I co-operate with the aromatic amines to produce a synergistic antioxidant effect it is believed that the mechanism may involve a regenerative process. It is believed that during oxidation of the oil, oxidation Intermediates oxidise the molybdenum compound to a higher oxidation state. It is then believed that the aromatic amine is able to interact with the higher oxidation state molybdenum compound reducing it so that the original molybdenum compound of low t oxidation state is regenerated with the diphenylamine being converted to a quinone inteirondiate. It is necessary therefore if the above is mechanism is correct that the molybdenum compound is in oxidation state five or less t.o that the molybdenum can be oxidised to a higher oxidation state. It is also necessary that the redox potential of the higher oxidation state molybdenum compound and the diphonylamine are such that the higher oxidation state molybdenum compound can be reduced to a lower oxidation state.

It is also envisaged that mixtures of molybdenum compounds of general formula I may be used andlor mixtures of oil-soluble aromatic amines may be used as the lubricating oil additive of the present invention.

28 Also provided by the invention is the use as a lubricating oil antioxidant of a combination of an oil-soluble molybdenum containing compound of general formula I and at least one oil-soluble aromatic amino.

In another aspect the invention provides for a lubricating oil composition which comprises a lubricating oil and a lubricating oil additive comprising the combination of an oil-soluble molybdenum compound of general formula t and at least one oil-soluble aromatic amino. The concentration of the lubricating oil $UB~irt~~ Sbt~ BU rA 'i i;--i WO 95/07963 PCT/EP94/03064 -6additive is typically In the range of 0.01 to about 15% by weight based on the total weight of the composition and is preferably from about 0.1 to about 7% by weight.

Suitable lubricating oils for use in preping the lubricating composition include those oils which are conventionally employed as crankcase lubricating oils for internal combustion engines and those which may be employed as power transmitting fluids such as automatic transmission fluids, hydraulic fluids, or gear lubricants, The lubricating oil may be a synthetic oil such as for example alkylesters of dicarboxylic acids, polyglycols and alcohols, polyalphaolefins, alkylbenzenes, organic esters of phosphoric acids, or polysilicone oils.

The lubricating oil may be a natural oil including mineral oils which may vary widely as to their crude source e.g. whether paraffinic, naphthenic or mixed paraffinic-naphthenic; as well as to their formation, e.g. distillation range, straight run or cracked, hydrorefined, or solvent extracted.

The invention further provides a lubricating oil concentrate. In the preparation of lubricating oil compositions it is a convenient practice to Introduce additives in the form of a concentrate; which introduction may be made by methods known in the art The lubricating oil concentrate may contain between 2.5 to 90 weight percent more preferably 5 to 75 weight percent of the additive composition in a suitable solvent. Suitable solvents may include hydrocarbon oils e.g. mineral lubricating oil or synthetic oil.

The ratio of Mo compound of general formula I to the oil-soluble aromatic amine may be selected so as to povide on antioxidant effect of sufficient magnitude to meet the end use requirements of the lubricating oil for example, to achieve adequate performance in the Sequence III E engine test for crankcase lubricating oils (according to the procedure of ASTM STP315) Preferably the Mo compound of general formula I and the oil-soluble aromatic amine are employed in a ratio of from 1:10 to 101 (by wt), more preferably from 3:1 to 1:3 (by wt).

U ~E E Fa WO 95/07'963 PCTIEP94/03064 .7- The lubricating oil additive may be used as the sole additive for the composition or concentrate or may be used in combination with several different types of additive which may be required to fulfill other requirements of the composition or concentrate during use. The composition may be used as a crankcase lubricating oil, a cylinder lubricant for applications such as marine diesel, industrial oil, functional fluid such as power transmission fluid, tractor oil, gear oil or hydraulic fluid. Accordingly the compositions or concentrates of the invention may in addition to the lubricating oil additive contain one or more of the following: a disparsant, preferably an ashless dispersant; a metal containing detergent, preferably having a high total base number; an antiwear or extreme pressure additive; a viscosity index improver, which may also have dispetsant properties; s1 a pour point depressant; a corrosion inhibitor and/or metal deactivator; and a friction modifier or fuel economy agent, as well as other additives such as demulsifiers, seal swell agents, or Oven supplementary antioxidants.

Where such compositions are for use as crankcase lubricants they preferably contain at least; an ashless dispersant and/or a viscosity index improver dispersant, a detergent, and an antiwear additive in amounts effective to provide their respective functions.

Dispersants The preferred ashloss dispersant in the compositions and concentrates of this invention is a long chain hydrocarbyl substituted mono. or di. carboxyli acid material, i.e. acid, anhydride, or oster, and includes a long chain hydrocarbon, generally a polyolefin, substituted with an alpha or beta unsoturated 04 to 010 carboxylic acid material, such as itaconic acid, maleic acid, mateic anhydride, chloromaleic acid, dimothyl fumarate, chloromatoic anhydrido, acrylic acid, mothacrylic acid, crotonic acid, or cinnamic acid. Preferably, the dispersant contains at least about I mole (e.g 1.05 to 1.2 moles, or higher) of the acid k~JtLI4E $N ;Ut A I 11 I WO 951079;0 WO 95079~PCT1EP94/03064 material per mole of polyolefin. The proportion of the dispersont is preferably from I to 10 and especially 3 to 7 weight percent of the lubricating oil.

Preferred olefin polymers for the reaction with carboxylic acids ore polymers 6 derivad from a 02 to C$ monoolefin. Such olefins Include ethylene, propylene, butyleno, isobutylene, pentene, wc4-1-ene or styrene. The polymers may be homopolymors such as polyisobutylone or copolymers of two or more of such olefins. These Include copolymers of. ethylene and propylene; butylene and isobutylene; propylene and isobutyleno; etc. Other copolymers include those in io which a minor motor amount of the copolymer monomers,. e.g. I to 10 mole percent, is a 04 to 01 diolefin, a copolymer of isobutylene and butadieno; or a copolymer of ethylene, propyleno and 1,4-hexadiene; etc.

In some cases, the olefin polymer may be completely saturated, for example an is ethylerie-propylono copolymyer made by a Ziegler-Notto synthesis using hydrogen as a moderator to control molecular weight, The olefin polymers u~sually have number average molecular weights above about 700, including number average molecular weights within the range of from 1,500 to $,000 with approximlately one double bond per polymer chain. An especially suitable, starting material for a dispersarit rAdditivo is polyisobutylone.

The number average molecular weight for such polymers can be determined by several known techniques. A convenient method for such determination Is by gel perme ation chromatography (GPC) which additionall.y provides rnolocular weight distribution information, see W.W You, J.J Kirkland and Oly, "Modern Size Exclusion Liquid Chromatography," John Wiley and Sons, Now York, 1070.

Procesases for reacting tthe olefin polymer with the unsaturated corboxylie, acid, 3u anhydride. or aster are known In the Ort, Pot example, the olefin polymer and the carboxylic a-lid matetial, may be simply hoated together as, disclosed In U$- AN3 3616073 and 3 401118 to cause a therml "one"' reaction to take plaCe Alternatively, thle olefirl polymer can be first halo( onated. for example chlorinated or brornnted. to about'l to~ 0, preferably 3 to 7, weight percent chlorine or bromine, based orl the weight Of P0lymor, by passing chorim or bromine, through the polyolefinv at a temperature of 10O* to 2,0110, a g 1201 to 160,,G, foriobout 0 6 to 10, peofetably I to 7 hours The halogenated polymor (RUL WO 95107963 WO 95101943 VP94IO3064 may then be reacted with sufficient unsaturated acid or anhydride at '10 0 to 25000, usually 1800 to 22010, for from 0.5 to 10, e.g. 3 to 0 hours. Processes of this general type ore taught in VS-A-~3 007 43K 3 172 892; 3 272 740 and others.

6 Alternatively the olofin polymer, and the unsaturated acid or anhydrido Oro mixed, and hooed while chlorine is added to the hot material. Process b.vp are disclosed In US-A-3 2163 707; 3 231 $07; 012 764; 4 110 i4; and 0B.A.-1 440 219.

When a halogen is used, from 6$ to 96 weight percent of the polyo'lefin n~ormnally rea-cts. wvith the, calrboxylip. acid or anhydridq Thermal reactions, carriedi out without the use of halogen or a cotalyst, cause only from 60 to 7$ weight percent or the polyiobutylone to react. Chlorination increases reactivity.

16 The carboxylic acid or anhydride cant than be further recofwith amines, alcohols, lncluling polyols, omino<ilcohols, oeto, to form othor usott dispersant additives. Thust If the acid or ainhydride Is to be further roactod. o j noutraliZed, then gonprolly a major propcrtion of at loot 60 percent of the acid tinits up to all the acid units will be reacted, Useful amino compound,, for roxactiort with the hydrocorbyl subs,)tituted carboxylic acid or anhydride includec mono and polyamineso of from 2 to 00, ej g 3 to total Carbornwrnq and from 1 to 12, o g, 2 to 0, nitrogen atoms in a molecule 2G Theo amines mnay be, hydrocorbyl ominesr or may lie hydrocarbyl amlies including other Uroupc, e4j hydro)xy groups, alkoxy grouips, ido 9roups, nitrites, or imidozolina groups, Hydroxy oimines with I to 6 hydIroxy Uroups, preferably I to 3 hydroyy groupsj, aro particularly useful Preferred arninea are aliphatie saturotod OUMnos, it.

1 IlUdirlg those of the gonerat formulae R7 14Nj 1 CNA)NR RU andtR WO 91/07963 WO 9~079~3PCTIIP94/03064 wherein R 7

R

8 and RO are each hydrogen; 01 to 025 straight or branchedi chain aikyl rodicals; C1 to C12 alkoxy-,(Ce olkylene) radicals; 02 to 012 alkylomino-(C2 to 06 alkylone) radicals;, each s con be the same or -0 different number of from 2 to 6, preferably 2 to 4; and t is a num 1 ber from Q to prefrably2 to est one of R 7 RO and RO must be hydrogen.

Suitable amines inolude; 1,2,4iaminootharie; I,$-diominopropone; I ,440dianobutono; i ,a-diominothexono; polyethylene amines such as dinthytone tricine; triethylene tetramine; 1 otronthyleno pontomino; polypropylene orninos such as 1,2.propyloe diamino; di-(1,2.propylen0)triomine, di(1,3-propyleno)triamine; N,N-dimothy.1 ,3.diominopropano; N,N-di-(2-aminothyl) ethylene diamino;N ~i~hdoyty)13poyed~ii; 3,, dodoyloxypropylamine,- NdodacykI1,3-propone diamine; tris hydroxymothylaminomothano (THANI); diisoproppnol amino, diethonol amino, 16 triothonol amine; amino morpholino4s uch as NWG3 amino-propyi) morpholino; Other useful amine compounds iniclude: aiioyclia diamine5s uch as I A4i40minoinothyl) cycloheone, and hoterocyclic nitr0on comnpounds ouch lmidozolinos, and N,-ominioalky1 piperazines of the gornorat formnulaijj 4 N\ 7K N+02P whoroin onJ in are tho some or difforcnt nd, each is an inteo,3r from I to 4, and fli, (14,d 3 r th0!%irme or difforont and ea~h ia aft integjer froni- I to 3 Examplos of suc.h nminieo includo 2-pefilnadp- yt imidazoline ond Nydroxyammose whiCh etan be roe(o with the long Chaini hydrociatb(,f Gubstituttd d] Iklrtoxylic, matorial mintionad abovo to form disporsants incluclo 21 o i I b uta'inoD ll, 2i 2,mot hyl~ t- propol, p (botcl hydroxyothyl), I ,propanct-t, 42. arMinrl o l 3popnd- N-(bota hydroxy propy',)NW £0q h Z(iLWJf WO 95/07963 WO 95107963 Cf/JEP94103064 -Ii- (bota-arninoethyl)-piperozine, othanolamine and beta-(beta-hydrxyethoxy)ethylamlr'e. Mixtures of these or similar amines cant also be employed.

Commercial mixiwres of amine compounds may advantageously be used. 'Por example, one process for preparing alkyleo omines involves the reaction of a n dihalide (such as ethylone dichloride or propylene alchloride) with ammonia which rosults in a complex mIlxture of alkylene amninos wherein pairs of nitrogons are joined by alkyleno Oroups, forming such comlpounds as diethylane tniamino, triothylone tetromine, totraothylene pentaminQ and corresponding piporazinos. Low cost poly(othylonoomine) compounds averaging about to 7 lo nitrogen atoms per molecule are available commercially under trade names such as "Polyamino "Polyamine 400, "Dow Polyomino V -1 00"1 etoc Useful aminos also include polyoxyalkylone polyaminou svch a thOse Wt IhW formulae: NH2-alkylono(O-olkyleno)n NH-2 Where m, has a value of horn to preferably 10 to 36; ond (ii) R-(alkylono(O-olkyte'io)n NH2)IG where each n hais a value of about I to 40, with the proviso thatd the $um of all the Nos is from ~3 to 70 aond preferably from 0 to 35, and R is a saturated'hydricorbon radlicat of up to ton carbon atomrs, wh1rvln the number of ,Ibstituents on tha R quoup is from 3 to 0. The alkylefie groups In oither tormula or (ii) May be straight or branched chains containing rabout 2 to 7, nnd prefera bly about 2 to 4, arboni atoms Tho polyoxyalkytono polyaftnos abovo, preferably polyoxyalkylono diarmons and polyoxyalkyfeno triamiines, may have aiverage moleo;Llare weights rainging from 200 to 4,000 and preferably fromW40 tro f2OOOr The preforrod polyoxyalkyloI no plolyam'T'lng irtcluda tho potyoxyethylone and polyoxypropytono diaminos and the pTolyoxyVp;opylOOO triamines having average molecular weights ranin~fro 20 t 2~0~The polyoxyalkylone polyamines ar ommrial availablo an'd way be obolamed, for example, from) the defferson-- Ohemni -a Gompany lor- unr the tnAde namie '"Jeftam;ine D; 230, O 41]0. 010003, ID.

WO 95107963 WO 95/0963 PcTEP94103064 12- The amine Is readily reacted with the carboxylic acid material, e.g. alkenyl succinic anhydride, by heating an oil solution containing 5 to 95 weight percent of carboxylic acid material to from 100 to 2609C, preferably 125 to 176"C, generally for I to 10, e.g. 2 to 6 hours, until the desired amount of water has a been removrd. The heating Is preferably cari1ed out to ftour formation of imides, or mixtures of Imides and amides, rather than omides and salts.

Reaction ratios can vary considerably, depending upon the reactants, amounts of excess amine, type of bonds formed, etc, Generally from 0.3 to 2, preferably fromn 0.3 to 1 .0 e.g. 0.4 to 0.8, mole of amino, e.g. bis-primary amine, is used, io per mole of the carboxylic acid moiety content, o~q. grafted maloic anhydride content, For example, one mole of olofin reacted with sufficient maleic anhydride to add 1. 10 mole of maloic anhydride groups or mole of olefin when converted to a mixture of amides and imidos, about 0.5 moles of amino with two primary groups would preferably be used, ia. Q.$0 mole of amino per mole of cdicarboxylic, acid moiety.

The nitrogon-contalning dispersant can be further treated by boration. as generally taught in US-A-S 087 930 and, 32$4 026, Tris (hydroxyrniethyl) amino methane (THAM) can be reacted with the aforesaid acid material to form amidos, imides, or ester typo additives as taught by GB.A.084 409, or to formt oxozolino compounds and boroted oxazolino compounds as described, for example, in US-A-4 1 02 708, 4 11W 876 and 4 '13 The ashless disporsants may also be esters derived from the long chain hydroearbyt subttitutod carboxylia Ocid material and from, hydroxy Luc as ,oo i and polyhydric alcohols oraoai opud uha phenols mnid naphthols, Wt. Thie polyhydric alcohols are the most preferred hydroxy compound and preferably contain from 2 to 10 hydroxy radicals, for example, othylene glycol, diethyleno glycol, tr;,,thylono glycol, totrctethylerle glycol, dipropyleno glyCol, and other olkylene qlycols in which. the Olkylone Inicludo glycerol, mnoolefate of glycecrol, moniostearato of glycerol, moniomothyl other of ulycorco!, pentaerythfitot, dipontanrythritol, 0t1 (PUL~ WO 95107963 WO 957963PT1EP94103064 -13- The ester dispersent may also be derived from unsaturated alcohols such as allyl alcohol, cinnamyl alcohol, propargyl alcohol, 1-cyclohexane-3-ol, and oleyl alohol. Still other classes of alcohols capable of yielding the esters comprise the other-alcohols and 'gmino-alcohols Including, for example the oxy-alkylene, s oxy-arylono., amino-ollkylene-, and amino-arylene-substituted alcohols having one or more oxy-olkylene, omino-alkyleo or omino-arylene or amino-arylene oxy-arylone radicals. They are exemplified by Cellosolve, carbitol, N, N, N',N'-tetrahydroxy-,tri-methyleno di-amine, and ether-alcohols having up to about ISO oxyalkylene radicals In which each alkylene radical contains from I to 8 corbon atoms.

The ester dispersant may be a di-oster of succinic acid or an acidic ester, i.e. a partially estorifiod succinic acid;~ or o partially esterifieci polyhydric alcohol or phenol, i.e. an ester having free alcoholic or phenolic hydroxyl radicals.

is Mixtures of the above Illustrated esters are likewise contemplated, 'rhe, ester dispersant may be prepared by one of several known methods as Illustrated for example in US-A-$ 381 022.

Mannich base- type. dispersants such as those described in US.-A-3 649 220 and 798 165 may also be used In these compositions. Such Mannich base dispersants can be formed by reacting a high molecular weight, hydrocarbylsubstituted mono- or polyhydroxyl, bonzene having a number average molecular weight of 1,000 or greater) with aminos (e.g polyalkyl polyamines, polyalkenyl, polyaminos, aromatic amino$, carboxylic acid-substituted polyamines and the succinimide formed from arty one of those with an olefinlo succinio ocId or anhydri&v) and carbonyl compounds (eog. formaldehyde or para fotrMoldehydo).

3o A particuliariy suitable dispersant is one derived fromi polyinjobutylano substituted wilh sucoinic Onhydrie- groups and reacted with polyethylene aminies, e.g.

tetroethyleno pontamine, pentaothylono hoxaine, polyoxyothylene and polyoxypropylono omities, e g. polyoxypropylenoe diamine, trismothylolaminomrethanoe and pentoerythritol, and combinations thereof.

~~ITJ~ESHUT (OiUC 2'1 WO 95/07063 WO 9510796TI~ EP94/0300~4 -14- Detergents Metal-containing rust Inhibitors and/or detergents are frequently used with ashless dispersants. Such detergents and rust Inhibitors Include oil-soluble 6 mono. and di-arboxyllc acids, the metal salts of sulfonic acids, alkyl phenols, sulfurized alkyl phenols, alkyl salicylates and naphthenates in neutral or basic form. Highly basic (or "over-based") metal salts, which are frequently used as detergents, appear particularly prone to promote oxidation of hydrocarbon oils containing them Usually these metalocontaining rust Inhibitors and detergents are used In lubricating oil in amounts of from 0.01 to 10, e,g, 0.1 to 5, weight percent, based on the weight of the total lubricating composition.

Highly basic alkali metal and alkaline earth Metal sulfoniats are frequently used as detergents. They are usually produced by heating a mixture comprising an 1s ol-soluble sulfonate or, alkaryl sulfonic acid, with an excess of alkali metal or alkaline earth metal compound above that required for complete neutralization of any sulfonlo acid present and thereafter forming a dispersed carbonate complex by reacting the excess metal with carbon dioxide to provide the desired ovorbasing. The sulfonic acids are typically obtained by the sulfonation of alkyl 2o substituted aromatic hydrocarbons such as those obtained from the fractionation of petroleumn by distillation and/or extraction or by the alkylation of aromatic hydrocarbons as for example those obtained by olkylating benzene, toluene, xyleno, naphthalene, diphonyl and the halogen derivatives such as chlorobenzene, chlorotoluene and chloronaphthalene. The alkylotion may be 26 carried out in the presonce of a catalyst with alkylating agents having from about 3 to more than 30 carbon atoms. For example, haloporoffins, olafins obtained by dehydrogenation of paraffins, polyolofin polymers produced from ethylene, propylone, etc. are all suitable. The alkaryl sulfonatos usually contain from 9 to or more carbon atoms, preferably from 10 to 50 carbon atoms per alkyl substituted aromatia moiety.

The, alkali metal or alkaline earth metal co~mpounds which may be used inl neutralizing these alkaryl sulfonile acids to provide tho sulfanatos include~ the oxides and hydroxides, olkoxidos, carbonates, carboxylatos, sulf ides, 3s, hydrosulfides, nitrates, boratos and others of sodium, magnesium,. calcium, strontiumn and barium., Sxamples are calcium oxide,, calcium hydroxide, magnesium oxide, rnagrtsium acetate arnd magn,,resium; borate As noted, the X, WO 95/07963 PMT P94/03064 alkaline earth metal compound is used in excess of that required to complete neutralization of the alkaryl sulfonic acids, Generally, the amount ranges from 100 to 220 percent, although It is preferred to use at least 125 percent of the stoichiometric amount of metal required for complete neutralization.

Various other preparations of basic alkali metal and alkaline earth metal alkaryl sulfonates are known, such as US-A-3 150 088 and 3 150 089 wherein ovorbasing is accomplished by hydrolysis of an alkoxide-carbonate complex with the alkaryl sulonate in a hydrocarbon solvent-diluent oil.

Preferred alkaline earth sulfonate additives are magnesium alkyl aromatic sulfonate additives having a high total base number (TBN) as measured by ASTM 02896 of at least 250, more preferably ranging from 300 to 400, and calcium alkyl aromatic sulfonates having a TBN of at least 250, preferably 300- 400.

Neutral metal sulfonates are frequently used as rust inhibitors. Polyvalent metal alkyl salicylate and naphthonate materials are known additives for lubricating oil compositions to improve their high temperature performance and to counteract deposition of carbonaceous matter on pistons (US-A-2 744 069). An increase in reserve basicity of the polyvalent metal alkyl salicylates and naphthenates can be realized by utilizing alkaline earth metal, e.g. calcium, salts of mixtures of C8- C26 alkyl salicylates and phenates (US.A.2 744 069) or polyvalent metal salts of alkyl salicylic acids, said acids obtained from the alkylation of phenols followed by phenation, carboxylation and hydrolysis (US-A-3 704 315) which could then be converted into highly basic salts by techniques generally known and used for such conversion. The reserve basicity of these metal-containing rust inhibitors is useful at TBN levels of between 60 and 150. Included with the useful polyvalent metal solicylate and naphthenate materials are the methylone and sulfur bridged materials which are readily derived from alkyl substituted salicylic or naphthenic acids or mixtures of either or both with alkyl substituted phenols.

Basic sulfurized salicylatos and a method for their preparation are disclosed in US-A-3 595 791. Such materials include alkaline earth metal, particularly magnesium, calcium, strontium and barium, salts of aromatic acids h,,'ing the 3a generalformula: HOOC.ArRtOOH.Zw(ArROOH)r SW4T1Tr (ttEF 4 fiiL aEt

I

WO 95/07963 WO 9507963PCT/EP94103064 where Ar Is an aryl radical of I to 6 rings, R 1 0 is an alkyl group having from 8 to carbon atoms, preferably 12 to 30 carbon atoms (optimally about 12), Z Is a sulfur or methylene bridge, w is a number from 0 to 4 and r Is a s number from 0 to 4.

Preparation of the overbased methylene bridged salicylate-phonote salt Is readily carriod out by conventional techniques such as by alkylation or a phenol followed by phenation, carboxylation, hydrolysis, methylene bridging a coupling agent such as an alkylone dihalide followed by salt formation concurrent with carbonation. An overbased calcium salt of a methylene bridged phonol-salicylic MWcid of the general formula, OH OH HOWC CH C12H 2 012H4 with a TBN of 60 to 150 is also useful.

Another type of basic metal detergent, the sulfurized metal phonates, can be considered a metal salt, whether neutral or basic, of a compound typified by the general formula:

OH

OR

R11 qOR where I t: I or 2, q r, 0, 1 or 2 or a polymeric form of such a compound, where III IIs an alkyt radical, 1 and q ore each integers from i to 4, and the average number of carbon atoms in all of the R groups is at least about 0 in order to ensure adequate solubility irn oil, The individual 1 1 1 groups may each contain SIo1U: S!Ei M -(fELNx sc WO 95107963 WO 957963PTEI194103064 -17from 5 to 40, preferably 8 to 20, carbon atoms. The metal salt is prepared by reacting an alkyl phenol sulfide with a sufficient quantity of metal containing material to Impart the desired alkalinity to the sulfurizod metal phenate.

s Regardless of the manner In which they are prepared, the sulfurized alkyl phenols which are useful generally contain from 2 to 14 percent by weight, preferably 4 to 12 weight percent sulfur based on the weight of sulfurized alkyl phenol.

io The sulfurized alkyl phenol may be converted by reaction with a metal.

containing material Including oxides, hydroxides and complexes in an amount suficont to neutralize sold phenol and, If desired, to overbase the product to a desired alkalinity by procedures well known in the art. Preferred iN a process of neutralization utilizing a solution of metal in a glycol other.

is The neutral or normal sulfurized metal phenate3 are those in which the ratio of metal to phenol nucleus is about 41:. The "ovorbased" or "basic!' sulfurized metal phonates are sulfurized metal phonates wherein the ratio of metal to phenol is greater than the stoichiometric ratio, o.g. basic sulfurized metal 2o dodecyt phonate has a metal content up to (or greater) than 100 percent in excess of the metal present (inthe corresponding normal sulturizod metal phonate, The excess metal Is produced in oil-solublo or dispersible form (as by reaction with 002).

2s The detergents which may be included in the~ compositionns of the present invention may optionally be borated in a known manner, $uch borotion provides the detergent with a measure of anti-wear activity.

It is preforred to use A combination of metal-containing detergents comprising ao calciumn and magnesium salts or calcium, magnesium and sodium salts, as described above, Antlwear Additives (Including oxtroma prossura agents) 33 A wide voriety of antivwear additives may be included in the compositions or concentrates of the invention, For example, organia tulphides end polysulphidos Including especially dialkyl, sulphidet and polysulphice5t Oeq WO 95/07963 9/93PC/P94/03064 18dibutyl polysulphides, and ciibenzyl sulphides and poilysuiphides, whic.h may be substituted, e.g. with halogen, may be incorporated In the compositions or concentrates. Suiphurized esters, e.g. suiphurized methyl or isopropyl oleate and other suiphurized compounds, e.g. sulphurizod olefins such as suiphurized dilsobutylene, swlphurized tripropylene or suiphurizod dipontene may also be added to the compositions, More complex suiphurized compounds such as sulphurized alkyl phenols and suiphurized terpenes and Diels-Alder adducts and sulphurized polymers, e.g. butodiene/butyl acryloteo opolyme rs, ma y also b e used as may sulphurized tall oil fatty acid esters. sters of beta-thiodipropionio l0 acid, e.g. butyl, nonyl, tricloyl or eicosyl esters may also be used.

Anti-wear additivWes in the form of phosphorus esters, e.a. di. and tri.-Olkyl, cycloalkyl or aryl phosphites, may also be used. examples of such~ phosphitos include dibutyl phosphite, dihexyl phosphite, dicyclohexyl phosphito, alkyl phenyl 16 phosphites such as dimethylphonyl phosphite and mixed higher alkyl, e.g. oleyl, and alkyl phenyl, e.g. 4-pentyl phenyl phosphite. Poosphites based on, polymers such as low molecular weight, polyethylenes and polypropyloes may 0lsa be used, Preferred anti-wear additives for addition to the compositions and conicentri~tes of the present invention are the dihydrocarbyl dithiophosphate metal salts. They also provide some antioxidant activity. The zinc salts are most commonly used In lubricating oils in amounts of 0 1 to 10, preferably 0.2 to 2, weioht percent, based upon the total weight of the lubricating oil composition, Salts of other metals, e.g. barium and cadmium, can also be used. They may be prepared in accordance with known techniques by first forming a dithiophosphoric acid, usually by reaction of on alcohol or gi phenol with P286 and than neutralizing the dithiophosphoria acid with a suitable Zino compound Mixtures of alcohols may be used including mixtures of primary and Gecondary alcohols, secondary generally for importing improved antiwoor properties, with primary giving improved thermal stability properties, Mixtures of the two Oro particularly usoful In gonieral, any basic or neutral Zinc, compound could be used but the oxides, hydroxides ond carbonatoa are most generally employod.

3G Commercial addittves, frequontly containl an excess of Zino due to usco of otl excest of thei basic zinc coaipourici in the neutralization reattion.

WO 9.107963 WO 95/09~3PCTEP'94103064 -19.

The zinc dihydrocarbyl dithiophosphates usefvl In the present Invention Ere oilsoluble salts of dih)/drooarbyl esters of dithiphosphoric acids aind may be represented by tha following formula: [RI -O-PSZn wherein RI 2 and RI 3 may be the some or different hydrocarbyl radicals contairnn from I to 18, preferably 2 to -12, carbon atomsw 1and including radicaks such as alkyl, olkenyl, aryl, arolkyl, olkaryl and cycloaliphatio radicals, Particularly preferred as R 12 and R 1 3 gro ups ore olkyl groups of 2 to 8 carbon atoms. Thus, the radicals may, for example be ethyl, n-propyl, i-propyl, n-butyl, I-butyl, oeo-butyl, omyl, s-hexyl, i-hexyl, I-octyl, cdocyl, dodacyl, octaecyl, 2ethyihoxyl, nonyl-phonyl, dodocyl-cyclohoxyl, methylcyclopentyl, propenyl, is btenyl, otc. In order to obtain oil solubility, the total number of caro ato~ms

R

12 and R 13 in the dithiophosphoric acid gjenerally should be about 6 or greater and preferably 8 or greater.

Borated derivatives of the aforesaid antiwevir agents may olso bt included in the compositions or concentrates of the invention.

Additional Antloxldants Additional vitioxidonts which are especially useful in lubricating oil compositions 26 or concentrates ore based on oll-solublo copper compounds, o g. in the form of a synthetic or natural carboxylio acid salt, Bly "Oil-solublo" is Meant that the compound is oil-soluble or solubilized under ntormal blending conditions In the oil or concentrate. EXOmpleIs Of oIl-SOtUble copper compounds include salts of Cjo to 018 fatty ocids juch as steoattc or patmIii acid; but unsaturated acids 3o (such as olei acid), branched carboxylic acids (such as nophtheniG acids) of Molecular waight from 200 to 600, Oicarboxylia acids such a5 polyisobutonyl succinic, acids, and synthetic carboxylia, acids can alt be used becouse of the wv" JTIM't'E"

W

Wo 91/07963 WO 9~I796$ CTIEP94/03064 acceptable handling and solubility properties of the resulting copper carboxylates.

Suitable ol-soluble copper dithiocarbamates hove the general formula

(R

14

R

15 N.CS.S)pCu; where p is 1 or 2 and R 14 and R 1 may be the some or different hydrocarbyl radicals containing from I to 18B carbon atoms each and Including radicals such as olkyl, aIkenyl, aryl, arolkyl, alkaryl and cycloaliphatic radicals, Particularly preferred as R 14 and R 1 5 groups are alkyl groups of 2 to Es carbon atoms. Thus, the radicals may be, for eomole, ethyl, n-propyl, n-butyl, I.

io butyl, sec-butyl, amyl, secohexyl, i-hoxyl, i-octyl, doyl, dodecyl, ootadocyl, 2' ethylhexyl, nonyl-phonyl, dodocyl-phonyl, cyclohaxyl, rnethyloyclopontyl, proponyl, butenyt, etc. ln ordor to obtaini oil solubllfty, the tot-l nI be Wcro atoms R 1 4 and RI 6) generally should be about 6 or greo'tar.

is Copper salts of dithiophosphonic acids (the acid as described heroinbofore In relation to ontiwoar additives speif ically as zinic salts), copp -r sulfonates, phenatos and oatyl acotoniates can also be used.

These antioxidants can bW used in amounts such that, in the finol lubricating composition, a copper concentration of from 6 to 500 ppm is present, Other known, oil-soluble or oil-disparsiblo, and preferably liquid, antioxidonts may also be used in the compositions of the invention. lVxamples of such antioxidants Include hindered phenols, which may contain sulphur, e.g.

2s 4,4'-mothyleno bis (2S di(t-butyl)phenol), 4,A~hio bis (2ZGd*-tbuty1)phenol} and p-alkylatod hindered phenols; unhindered phonols which again may contoin sulphur such as Z2'-thio bis-(4-nonyl phenol) and 2.2'Methylna bWS (4.

nonylphonol), phenothiozine derivatives, 0.9 those containing higher alkyl substituents such as dioctyl and dinoriyl phenothiozines.- substituted alpho and 3o botanaphthyl aminos such as phony! bota-~naphthylaMinO nd its Olkylated dorivatives; other ramlno, aryl compounds such as for example 4,41.

bis(secbutylamino) diphonylmethano, dithocorbamnatos such aq 2int, nickel, copper, or molybdenum dithiocarbaotes,, and phosplioulphLuriz'O,1 olefm'~ tt phosphogulphurized PiO or styrene WO W07963 WO 950796 1O/EP'9V103064 -21-.

Corrosion Inhibitors and Metal Deoctivators Corrosion inhibitors which act by' deactivating metal parts with which they come in contact and/or as s.o.lphur scavengors can also be used, in the compositions or 6 cv- -,entrates of the invention. Examples of such agents Include bonzotriozole derivatives, thiadiozole compounds, e.g. 2,64dmercopto 1 ,3,4-thiadiazoie; mercoptobenzothiazole compounds In the form of amino salts, sulphonomides, thiosuiphonamidos, and condensates of mercaptobenzothiazole with amines and formaldehyde; salioyialdehydeldiamino condensation products; dialkyiphosphltes, e.g, dioloyl or di-2-othylhoxyl phosphito, trialkyl and Iriarylphosphites, e~g. tris,(2-eth ,!'hexyi), triphonyl or tri(4-'nonyiphenol) phophies;andthiphophonate".-- suhch strip~hony or trilauryl thiophosphonate or trilauryl tatrothiophosphonoto.

Friction Modifiers and Pool economy Agents Friction Modifiers and fuel economy agents which are compatible with the other ingredients of, the now compositions or concentrates May also be included.

Examples of such materials are glyceryl moroostors and/or diesters of higher fatty acids, o.q. giyceryt mono-.oieate and Wstr of long-chain polycatboxylic acids with diols, o~q, the butane diol ester of a dirrzed unsaturated fatty 0cid, and oxazolino compounds.

215 V1iscosity Indox lmprovors Viscosity Index improvers, or viscooity Modifiers are typically polymers of number avercijo molecular weight 103 to 106 for example Othylene copolymers, or polybutenos Viscosity index improvors may be modified to~ havo disporsant 3o properties ond suitable visco.,Ity index improver dispersants for use Int compositions of the Invention are described in, for example, Eiuropooan Specification No 24 1 4E A.

polymort comprisin) monomer units derid fr 0 04 to 624 ~~unsatufAted ester of vinyl Otcohol Or a C0,- to 040 urnatujrated tnorno~or dicarboxyiic acid ornd on unsaturated rlrgr~ot~ in c noer having 4 to, 201 carbon atomis.

WO 95/07963 WO 9517963 ~17IMEP941030611 to 2210 polymers comprising monomer units derived from a 04 to C20 olofin and or., unsoturoted 03 to 0IQ mono-or dicarboxylio acid neutralised with ant amino, a hydroxyornlne or on alcohol; and polymers of ethylene with a 03 to C20 olef in further reoeoitoct by grafting a 04 fQ 020 nitrogon-containing monomer thereon or by grafting an unsaturated acid onto the polymer ackbone and then reacting the carboxylic acid groups with on omiriv-, hydroxy amrine, or alcohol. (The European specification also gives examples of various other additives which may be used in accordance with the present invention.) These viscosity indeX ImprovOr l"84 aySONv dispe-rsmnt pronartieq, as in preo rred in accordance with the invention, althouoh viscowsity index improvers without dispersant propertios may be used it desired, Is Preferred viscosity index improvers with diqspersant properties for use in the compositions of the present invention comprise a poly~oeiVt moiety to which i s grfed an unturated carboxylieaoid moiety, the carboxylic acid gropbin reacted with on aminie, hydroxyamine or alcohol.

Antioxidants may be evaluated usino the sequence III P teSt (A3TM STV3 SI) which is a stondard test used for assessing the oxidation rosisances of lubricants and which is o more 6tringent version of the sequence III U test (ASTM WT 316M OndA$TM STh315). The sequence Ill method produces a result otterN0 2s hrs of testing with an acceptable performance being a or lewri inore05e in kinematic viscosity as rnt)aured at 40 ofter this period. The principle of this method is to otiserve oil thickening a, a res~ult (if oxidation When evaluaiting antioxidants for klbrcants it is desirable to be able to uso screening test methods which are qu i n ea sier to use than thq reqince Ill test One 3o Guch method which is cormmonly used Is a thin filma high, tempera Wre Catalytic oxidation test porformed usiig u 00 WO 95/07,963 WO 9~O794~P1EP94O03O64 023- The invention will WQ further Illustrated by meoinq- of the followi:,g Examples: 6 Table I lists fotoils of the diphenykamines nominally of geneot structure It which wera used in the following examples.

Taible 1 No. Diphenyiwiinc %U I Trado Nattic 3 4 [~0rallOA 1502 Vantlube M[ Ignox~lb L3-O tMixture of G.4, Q on sw tyryl Mixture of CAi, (1 Mnd ostXyy MiXtUre of 1, bu.tyl In t-(Y'tyl

V

Vantube 848 Vcinj-tb DND The Diti'erorlbal Groorin Ontoriftetry (D~t0e6t method WOe In the oXOMPleS Compounds to be tested for onixInyp otmo "Iore added Lit the required, rtio te a~ sarmpl6 of lubri~ant oil contauiwri 600 ppm VF and 2009 Op.'I Pb T his tost Sample (0 Oml ispt e in the center of on alummuum MS0 pan and Inseited into a DufPi:nt 90(4 1 ih Pressre WO3$( The cell of the 030, is t heni then ho~ted III a prograntod ramyped rote cf- 100"Chmn tr-- tho isothcrmal temperaturo of 1 W10, After m periodJ of, tWm theo test sanmple un R ao OxothermiG Oxidotlvtk react"On. this 6OA 0ve1 admontu oil thei asocoteJ Ilea,* WO 95107963 11(/IE1941030 64 0~24effct cmpared to the inert reference are monitoroda rode Th oxidationl induction time (OJT, time tQ avto-oxIdztiof) is the time at which the basoline intersects with a line tonoont, to the curve of the exothermal heat flow versus time scan. The QIT is reported in minutes. The rnonltUdo of tho OtT Is 6 an indicotiofl of the effective, nos$ of the compounds$ or ompound mixtures under test as antioxidonts, the loaer the OIT the greater the antioxidont effect.

lUxamplos i to 7 A control formulation of lubricotinj oil woo tosted with each of the, .,.ienykarios l~tod in Toblo i with and. with~u a oydiuf opof0 the following~ qonor~il formula-

MO

Thq forma~ulationl in which thOemio Mnuhomlbdrm 00ompourldl w~rc~ testoo compl-isod an Am~oco Wiitif i base il and an additivo paCkaije 2q L whi-h Lot~I a.toy15nL)UtenYj cub't'WutQJ 6ur~oa onido diepersant, a. low bas numbor 031 'lum 5ulphonale, L! 400 total baso number mignesi;ll SulphOAMt0, ZODP andl a deornulfior 'The results kare vhomn Inl Table 2, 01 f. I 1 1-1, WO 9$107963 PCC/EP94/03064 Table 2 Test Diphenyl 0 ~~~ration WTOtT in minutes Amine OPA MO control or C ontrol or 0.PA Compound OPA only Molybdenum ompound, I none 0. QIS 21~ 2 Pocirsall OA QA3 0.6 7.1 16A4 3 Nougalube U 62$ 21.0 '4 VnLube SL 013 O.S. 0.4 25.1 6 Noujolube 013 110- WO0 6 lr~o=L57 (0$1 0,5 0 2717 '7 Vantube NO 0,3 05 173 These (eSUlts clearly $110v tho synorgisiki of.00ioxit effect If combhningl a molybdonum eCOM~ound ft aoorl0 formula I with ai diphvnylomiflo of gorneria) 1ormnula IL. This is flIOM notoble frorn the roult with, Vontlboe SU, it the effect Was purolyod6AtvO the expeCtoed rcsult would be 7 thct~ ic tho tesult of tho co, cul-ation, the volue of exampki I (with Mo compoxi.nd) vo;ue of examplo 4 (with iamtne, only)o voo fxmpeI(ihu ocpon)Teaul i& ExampIt 8 A Molybdenlum cimpound: whi-j io a commorcially aivailaibler~t~cds undor the tIr1de mirk MNlyvan 02A "n -oi 13 Ulioved to havoe the vnoMina otuLue btw, -is fvil'Vte With aihnlmns Ii hted irl table by mocans of the &jame 4~roto. ~omls .Jto2 wero carried out uvij the same base oit ondodJitive pakoje as i Lixaimpls 1.7, EixamptesN2 and- .0&were carriel 6ut usina0 S cieretit bast! uil narrely Petro~vcat ydor e with thef Same &ddihv 3 A~R jae n~ thft rosuiti, Which Afe Shownt tIn T"bLe show the WO 95107963 WO 510963P~IIEVP94/03064 synergistic effect Qosrved with the combination of molybdonuni compound of goneral formula I and diphonylamine of general formula 11.

OtHi a WO 9S/07963 WO~~~C 95093C1P94/03064 v27 Table 3 Test Diphonyl Concentration WT QIT In minutes Amino OPA Mo control or Control or Compound DPA only DPA Mo co~mpound 8 NONE 0.15 1.6 2.1 9 NONE 0.25 2.8 NOW: 0.50 2.9 11 Pearsall OA 502 0.3 0.15i 7,18, 12 Pearsall OA 602 0.13 0.25 7,1 11.9 13 Vonlube DNO 0,3 0.15 6.9 8.1 14 Vanluba DND 0.3 0.25 6.9 13.9 16 Vornlubo DND 0.3 0O5 6.9 17.1 16 Naugatubo 438L 0,3 0.15 6.2 9.6 17 Naugalube 438L 0.3 0.25 6.2 11.1 18 Vanlube SL2 0.3 0.1$ 6.4 8.1 19 V.,iliba SL 0.3 056A4 8. Nauglube 680 0,3 0.15 7.5 12.0 21 N u gQ.Iu be 0,8 0 0 0. 25 7.5 22 lr(g)nox L-57 0,3 0.15 8.5 9.7 23 Irganox 0__0.5_8__1Z 24 NONE:___ Pearsall 0A52 0 30516)4.

SUB2~tU~ S~1~ tfu £26) WO 95/07963 WO 9507963PCT(E P94/03064 -28- Comparative Experiment A molybdenum compound of formula MoS2DTC3 wherein the DTC represents a dithiocarbamate group and the molybdenum Is In oxidation state six was found to exhibit no synergistic antioxidant effect when used with cliphenylamines of general formula 11.

suasrUTE SHEET (iwvL 260J

Claims (7)

1. 4. A lubricating oil codditi as claimed In a on whof r the rec iclatimg 09 5. Albitigoil additive as pentaaco c aimed in an0 oe.0lim to 46%b wih he ina
2. 7.gh Af luctinoi compositiona lie ncam0whr~ h urctn oi adiiei rsn tacnetainof000o1%b egtbsdo oa
3. 8. A lubricating oil composition as claimed in claim 7 wherein the lubricating oil additive is present at a concentration of 0.1 to 7% by weight.
4. 9. A lubricating oil composition as claimed in claim 6 wherein one or more of the following additives are also present: a dispersant, a detergent, and antiwear additive, a corrosion inhibitor, a metal deactivator, a friction modifier, a fuel economy agent, a viscosity index Improver, and an antioxidant. A lubricating oil concentrate which comprises a solvent and the lubricating oil additive as claimed in any one of claims 1 to fi 11, A lubricating oil concentrate as claimed In claim 10 which comprisae between 2,6 to 90% by weight of the lubricating oil additive, 12, A lubricating oil concentrate as claimed In claim 11 which comprises between 5 to 76% by weight of the lubricating oil additive.
5. 13. A lubricating oil concentrate as claimed in claim 10 wherein the solvent Is a mineral oil or synthetic oil.
6. 14. A lubricating oil concentrate as claimed in claim 10 wherein one or more of the following additives are also present: a dispersant, a detergent, and antiwear additive, a corrosion inhibitor, a metal deactivator, a friction modifier, a 1* fuel economy agent, a viscosity Index Improver, and an antioxidant. 4
7. 16. The use of a lubricating oil additive as claimed in any one of claims I to 6 as an anntioxidant in lubricating oils, 31 16. A lubricating oil additive comprising MOLYVAN 822 (trademark) antioxidant (as hereinbefore described); and at least one oil-soluble diphenylamine. DATE~D this 22nd day of May 1097 EXXON CHEMICALP.ATENLaJNQ. WATERMARK PATENT TRADEMARK ATTORNEY$ 290 L3URWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA *P:S Do 007719.P INTERN4ATIONAL SUIWCE REP3001tr Inter, dflAl Alpligaton No 94/03064 A. CLASSIICATION OPSUIMA' I21t I PC 6 C10M0 8 //'C10M14i/08,133:12,J.35:18),C10NI11,C10N30:l10 According in International Patent Claxtfication (IPC) or to both riationall cluasication and IPC P3. FELDS M~ARCHIED minitum 40cumtcritaton varchod (clustic~ation mytem followed by Ci~s.~Ilatin Symboll) IPC 6 Clom Dowumenwtton sawhod Other than ~Mnlui 4O411140n0Atn to thq exctet "h 41101 d0"wMWn0 goe 1nClUd4d, in the~ fild$ Ruea~bd Electronic data bato w041110~4 dUnni; the tntrnatlonal Soutch (flaine of data basa Afld, whcr, prwacual zoar~h termev wed) DOCUM ENTS, CONSID lIUID TO PH RUIEfVA N Category *Citation of dixunnt, %ith hitliation, whce appropriate, of thd relevant jtastag Releva to Omi No. X UStA14 479 $83 (N.SHAUB) 30 Octoer 1984 1 3j 7-10,16 see column $1 line 16 line 19 see column 6, line 10 -line 16 see column 6, line 25 line 26 see column 7t line 26 -line X EP,,AQ 447 916 (NIPPON OIL CO.) 25 1-,10 September 1991 see page 3, line 16 see page 3, line 41 see page 3, line 52 lint 66 A WO,A,91 13955 (EWON RESARCH AND10 9 ENGINERING COMPANY) 19 September, 1991 see page 6, example I. trurUm douwnensitt tI4 iet tlht 0~Vn*UO hox P~ Iatent faily i~mbetf e jitkie in Arfmx unewino u.ea A* fMrovioty difanflti nt m Confict wWth W I~CAtof but t aitet d~uniei it publijbd Onl Ot 4fAt the IftftdW dcun c phxttiul vtg vainct the (turned iiVenrft ingo date cawqt b CowdRted novel or caivit b4 oisdtrv 4 'L docuwtnj which may throwdouts on prority duni) 01 Lawole an lrnvibtivt v~p w~ii the d'wriebnt thk~ia 4014 Which it i tcd to w*AbihI the pibcawcii dcoOrtt OfC~ Rn of 4d otp~eiar ltltailt4 the caihmcd tnvtnuon dtlocri or othtr sptdtM rtMnft( ip4~lnd) MuO b O ko~rtd to Involv6 Ant Itv~htetV vw w* nth O0 dcumeuntWetti aeng lt an oral dmloeture, Uir 4hibition ot doKuiment 11 combined with ome ot we I oue h "Wlt.oC othit lMrtn tilen, itsh comtbintioil bting ohvious to a P4"t 1killad V doftuhefltpeNbthed pelo* to the UifitetmI C1lifg d4w Wt L the Art, lattttft d1 0ii ,tety dle lAtite dou~i"uwtietrNlt cf tho wto p#O~t ftnily i* Of Utuil I C4r4 44 A of te1WPA4 ttr&I'*c ff 4I QIEO tOf 10 14i t41Otupnat im kihre ell fecember 1994 '2.tW Name* and lnit 9de~il ef (lIe BA AtU4f~ice [UtC.3In elentOffc, $t k~thi Ktgng, TAE 2+189l~ 341&ji' rcm PG? 13A Ilq (Wlhott th*4Qj1U1y lqfl Pp I of a INTH RNATIONAL SEAICI RIu.1OIR Inlt. nlt Apphiraown No IPCT/EP 4/364 PCT/EP 94/03064 I I -Onuvcsnuun l U-,u rd IN 4 a CONS LIMKED To 0 RELIWYAN r i ~~aCllnl ll I rr4rlvry n Of documCn, With 10a40n, Whore Appwpnatc, of U10 re'ant pusalges T-j1c-qvan% to 041~M No. W:,A,87 05045 (THE LUBRIZOL CORPORATION) 27 August 1987 see page 1, line 11 line see page 15, line 11 line 27 see page 1t; example 0 USA*4 846 983 (WC. WARD) cited in the application DATABASE WPI Section Ch, Week 7635, Derwent Publications Ltd,, London, GB; Class E12, AN 76-65766X JPAt5 080 825 (ASAHI DENKA KOOYO K) 16 July 1976 cited in the application see abstract GBA,1 097 372 VANDERBILT COMPANY) 3 January 1968 see page 2, line 1 line 8; claims 5,14 USA,3 356 702 (H.11. FARMER) Decober 1967 cited in the application USA,4 394 279 (LOUIS OR VRIES) 19, July 1983 cited In the application see Claims 1,025 1,5-16 1-317-91 16 L-o m KT ISA- 4j -en(AvoM Of gi 1 INTEJNATIONAL SEARICH RETOT 'I x ,A,*,plI PCT/EP 94/03064 Patent document P'ublicaton Pawnt family PubIIon cited In search toport, loto mber(s) y US-A-447983 30-10-84 NONE EP-A-0447916 25-09-91 JP-A- 3269094 29-11-91 DQ-D- 69102172 07-07-94 DE-T- 69102172 22-09-94 WO-A-9113955 19-09-91 GD-A- 2241707 11-09-91 UE-0- 69101376 14-04-94 E-T" 69101376 07-07-94 EP-A- 0523064 20-01-93 JP-T- 5504369 08-07-93 WO-Ao8705045 27-0-87 US-A- 4846983 11-07-89 AU-8- 620794 27-02-92 AU-A- 7120437 09-09-87 CA-A- 1279059 15-0191 DE-A- 3785760 09-06-93 EP-AD 0294388 34-12-88 JP-T- 1502184 03-08-89 ZA-A- 8701219 11-08-87 US-A-4846983 11-07-89 AU-B- 620794 Vi-02-92 AU-A- 7120487 09-09-87 CA-A- 1279059 15-01-91 DE-A- 3785760 09-06-93 EP-A,8 0294388 14-12-88 J)P-T- 1502184 03-08-89 WO-A- 8705045 27-68-87 ZA-A- 8701219 11-08-87 GO-A-1097372 0E<-A- 1518181 24-07-69 US-A- 3356702 US-A- 3509051 28-04-70 US-A-3356702 OE-A- 1518181 24-07-69 GO-A- 107372 US-A 3509051 28-04-70 US-A-4394279 19-07-83 NONE po~ ~t ~ll C~ ti) M~h*ET'dl I*,1