CA1327350C - Ashless lubricant compositions for internal combustion engines - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
In accordance with the present invention, there are provided ashless heavy duty diesel lubricating oil compositions which comprise an oil of lubricating viscosity as the major component and as the minor component (A) at least 3 wt.% of at least one ashless dispersant, (B) at least 2 wt.% of at least one sulfurized alkyl phenol, and (C) at least 0.1 wt.% of at least one organo-sulfur compound of the formula

Description

1327~0 FIEL~ OF THE INYENTION
This invention relates to lubricating oil compositions which exhibit marked reduction in engine carbon deposits. More particularly, this invention is directed to ashless lubricating oil compositions which are adapted for use in diesel engines and which contain ashless dispersants, sul~urized alkyl phenols and organo-sul~ur . anti-corrosion agents.
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~ BACKGROUND OF TH~_~NVEN~ION
` It is an objective of the industry to provide lubricating oil compositions which exhibi~ improvements in minimized engine deposits and low rates of lubricating oil consu~ption, particularly in diesel engine vehicles.
Among the conventionally used lubri ating oil additives, zinc dihydrocarbyl dithiophosphates perform multiple functions in the motor oil, namely, oxidation , inhibition, bearing corro~ion inhibition, and extreme pressure/antiwear protection for the valve train.
Early patents illustrated compositions using polyisobutenylsuccinimide dispersants in combination with zinc dialkyldithiophosphates which were employed in lubricating oil compositions with other conventional i additives such as detergents, viscosity index improvers, rust inhibitors and the like. Typical of thes~ early ;. di~closures are U.S. Patents 3,018,247, 3,018,250 and ~` 3,018,291.

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Since phosphorus i~ a catalyst poison for catalytic converters, and since the zinc itself offers a source for sulfated ash, the art has sought to reduce or eliminate such zinc-phosphorus-containing motor oil components. Exemplary of prior art references directed to the reduction in phosphorus-containing lubricant additives are U.S. Patents 4,147,640; 4,330,420: and 4,639,324.
U.S. Patent 4,147,640 relates to lubricating oils having improved antioxidant and antiwear properties which are obtained by reacting an olefinic hydrocarbon having from 6 to 8 carbon atoms and about 1 to 3 olefinic double bond~ concurrently with sulfur and hydro~en sulfide and thereafter reacting the resulting reaction intermediate with additional olefin hydrocarbon. These additives are disclosed to be generally used in conjunction with other conventional oil additives such as overbased metal detergents, polyisobutenylsuccinimide dispersants, and phenolic antioxidants. While it is disclosed that the amount of the zinc additive can be greatly reduc~d, giving a "low ash" or "no ash" lubricant formulation, it is apparent the patentee was referring to Zn-derived ash, and not total SASH levels.
U.S. Patent 4,330,420 relates to low ash, low phosphorus motor oils having improved oxidation stability a-~ a result the inclusion of synergistic amounts of dialkyldiphenylamine antioxidant and sulfurized pslyolefin. It is disclosed that the synergism between th~sQ two additives compensates for the decreased amounts of pho phoru~ in the form of zinc dithiophosphate. The fully formulated motor oils are said to comprise 2 to 10 wt.% of ashless disp2rsant, 0.5 to 5 wt.% of recited magnesium or calcium deterg~nt salt-~ (to provide at least O. 1% 9f magnesium or calcium), from 0.5 to 2.0 wt.~ of zinc dialkyldithiophosphate; from 0.2 to 2.0 wt.~ of a dialkyldiphenola~ine antioxidant: from 0.2 to 4 wt.% of a sul~urlzQd polyolefin antioxidant: from 2 to 10 wt.% of a " 13~73~0 first, ethylene propylene VI i~prover; from 2 to lO wt.% of a second VI improver consisting of methacrylate terpolymer, and the balance baseoil.
U.S. Patent 4,639,324 discloses that metal dithiophcsphate salts, while useful as antioxidants, are a source of a~h, and discloses an ashless antioxidant comprising a reaction product made by reacting at least one aliphatic olefinically unsaturated hydrocarbon having from ~ to 36 carbons concurrently with sulfur and at least one fatty acid e~ter to obtain a rea tion intermediate which is then reacted with additional sulfur and a dimer of cyclopentadiene or lower Cl to C4 alkyl sub~tituted cyclopentadiene dimers. It is disclosed that these additives in lubricating compositions are generally used in conjunction with other conventional oil additives such a neutral and overbased calcium or magne3ium alkaryl sulfonates, dispersants and phenolic antioxidants. It is disclo~ed that when using the additives of this invention, the a~ount of the zinc additive can be greatly reduced giving a "low ash" or "no ash" lubricant formulation.
Again, it is apparent that the patentee was referring to Zn-derived ash, and not to total SASH.
Metal detergents have been heretofore employed in motor oils to assist in controlling varnish formation and corrosion, and to thereby minimize the adverse împact which varnish and corrosion have upon the efficiency of an int~rnal co~bustion engine by minimizing the clogging of re~tricted openings and the reduction in the clearance of ~oving parts.
U.S. Patent 4,089,791 relates to low ash mineral lubricating oil compositions comprising a mineral oil base in ~inor a~ounts of an overbased alkaline ear~h metal compound, a zinc dihydrocarbyl dithiphosphate (ZDDP) and a substituted trialkanolamin~ compound, wherein at l~ast 50~
of the ZDDP co~pound~ consi~ts of zinc dialkaryl dithiophosphat-s, in order eo pro~ld- a for~ulatod ~otor .

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oil which will pass the M5 IIC Rust Test and the L-38 Bearing Weight Loss Test. The patent illustrates three oil formulations, containing overbased calcium detergent, ZDDP, trialkanolamine and unspecified conventional lubricating oil additives to provide visco~ity index i~provement, antioxidant, dispersant and anti-foaming properties. The illu^~trated formulations each had about o. 66 wt. 9c SASH
levels, based on the reported Ca and Zn concentrations. No diesel motor oil formulations are illustrated.
U. S . Patent 4 ,153, 562 relate~ to an~ioxi~ants, which are disclosed to be particularly useful for compounded lubricating oil~ that are intended for heavy duty use in automotive crankcase formulations of relatively low ash content, wherein the antioxidants are prepared by the condensation of phosphorodithioates of alkylphenol sulfides with unsaturated compounds such as styrene. The antioxidants are exe~plified at levels of from 0.3 to 1.25 wt.% in lube oil compositions (Example 3) which also contain about 2.65 wt.% (a.i.) borated polyisobutenyl-succinimide dispersant, about 0.0~ wt.% Mg as overbased magnesium sul~onate detergent inhibitor, and about 0.10 wt.% Zn as zinc dialkyldîthiophosphate antiwear agent (containing mixed C4/C5 alkyl groups).
U.S. Patent 4,157,972 indicates that the trend to unleaded ~uels and ashless lubricating compositions has neces~itated the search for non-metallic (ashless) substitutes for m~tallo-organo detergents, and relates to tetrahydropyri~idyl-substituted compounds which are disclo~ed to be useful as ashless bases and rust inhibitors. The Example~ of the Patent compare the performance of various lubricating oil formulations in a Ford V8 varnish test (Table I) and additional for~ulations, which are na~ed as either "low-ash" or '~ashles~", in a Hu~idity Cabinet Ru~t Test (Table II). The SASH levels of th- ~low ~h~ rormulation~ ar- not report-d and c~nnot be 13273~

determined from the information given for the metal detergent and ZDDP- components.
U.S. Patent 4,165,292 discloses that overbased metal compounds provide effective rust inhibition in automotive crankca~e lubricants and that in th~ absence of overbased additives, a~ in ashle~s oils, or when such additive~ are present in reduced amounts, as in ~'low ash"
oil~, ru~ting becomes a ~eriou~ problem. Such rust require~ents are evaluated by AST~ Sequence IIC
engine-tests. The Patent discloses a non-ash forming corrosion or rust inhibitor comprising a ~ombination of an oil-soluble basic organic nitrogen compound (having a recited basicity value) and an alkenyl or alkyl substituted succinic acid having from 12 to 50 carbon atoms. The ba~ic organic nitrogen compound and the carboxylic acid compound are required to be used together to achieve the desired rust-inhibiting properties. It is disclosed that best results are achieved by use of an excess of amine over that required to form the neutral salts of the substituted succinic acid present.
U.S. Patent 4,~02,970 relates to improved crankcase lubricating oil compositions containiny lubricating oil dispersant, overbased metal detergent, zinc dialkyldithiophosphate antiwear additive and polyi~o~utenylsuccinic anhydride, in recited amounts.
Exemplary lubricating oil formulations are disclosed containing 3 wt.% polyisobutenyl~uccinimide dispersant, polyisobutenylcuccinic anhydride, overbased mQtal sulfonate or overb~sed sulfuriæed phenate detergents and zinc dialkyldithiophosphato antiwear agents, in base oil, in amount~ of 3.0, 3.0, 2.0, 1.0 and 91.0 wt.%, respectively.
European Patent 24,146 relates to lubricating oil co~po~itions containing copper antioxidants, and ~xemplifies copper antioxidant~ in lubricating oil co~position~ al~o containing 1.0 wt. % of a 400 TBN
~agn~ium sulphonate (containing 9.2 wt. % magnesium), 0.3 ', .,.
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Wt. % of a 25û TBN calcium phenate (containing 9. 3 wt. 96 of calcium) and a zinc dialkyldithiophosphate in which the alkyl groups or a mixture of such groups having between 4 and 5 carbon atoms and made by reacting phosphorous P2S5 with a mixture of about 65% isobutyl alcohol and 35% of amyl alcohol, to give a phosphorous level of 1.0 wt.
~ in lubricating oil composition.
Published British Patent Application ~, 062, 672 relates to additive compositions comprising sulfurized alkyl phenol and an oil soluble carboxylic dispersant containing a hydrocarbon base radical having a number average molecular weight of at least 1300, which i5 disclosed in combination with ash-producing detergents.
However, it is extre~ely difficult to translate lube oil development~ intend~d for passenger car and light truck service, whether gasoline or light duty diesel engines, into lubricating oils intended for use in heavy duty diesel service.
R. D. Hercamp, SAE Technical Paper Series, Paper No. 831720 (1983) reports development work on engine tes~
proc2dures to measure the rel~tive ability of various lubricant formulations to control oil consumption in heavy duty diesel engines. The author indicates that lab analysis of crown land deposits on the diesel engine pistons show an organic binder to be present which contains high molecular w~ight esters, ~r.d the author speculates that oxidation products in the oil may be precursors for the binder found in the deposits. It is indicated that i~proved antioxidants could be the key to prevent premature 1088 0~ oil consumption.
A. A. Schetelich, SAE Technical Paper Series, Paper No. 831722 (1983) reports sn the eff ct of lubricating oil parame~er~ on PC-l type heavy duty diesel lubricating oil perormance. It is noted that over the pa~t 30 year~, the trend in heavy duty diesel oil industry has baen to decreas~ th0 sul~ated ash levels fro~ 2.5 wt.%

.

273~0 sulfated ash (SASH) in 1960 to the typical North American SASH lavel of 0.8 to l wt.%, and to correspondingly decrease the HD oils total base number ~TBN) D28s6 values from over 20 to the present typical North American TBN
values of from 7 to 10. Such reductions in SASH and TBN
levels are attributed by the author to bs3 due to improve~ent in performance of ashless components, including ashless diesel detergents and ashless dispersants. In diesel engine tests, no significant correlation was seen between the level of either piston deposits or oil consumption and the SASH or TBN levels, for about 1~ to 2%
SASH levels and about 8 to 17% TBN levels. In contrast, a significant correlation was seen between the level of ashless component treat and the amount of piston deposits (at the ~2% confidence level) and oil consumption (at the 98% confidence level). It is noted by the author~ that this correlation is drawn with respect to diesel fuels having average sulfur levels of less than about 0.5%. It is indicated that the level of buildup of ash is accelerated in the hotter engine areas. The author concludes that at the 97% confidence level there should be a correlation between oil consumption and piston deposits, especially top land deposits, which are believed to contribute to increased oil consumption due to two phenomena: (1) these deposits decrease the amount of blow-by flowing downwardly past the top land, which results in a dQcreased gas loading behind the top ring of the p~ston, which in turn leads to higher oil consu~ption; and (2) increa~ed bore polishing of the piston cylinder liner by the top land deposits which in turn contributes to higher oil consumption by migration o~ the oil into the firing chamber of the cylinder along the polished bore pathq. Therefore, the Paper concluded that reduced ash in the oil should be sought to reduce top land deposits, and hence oil consumpt~on.
This 1983 Schetelich paper reports formulation of .;

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2 test oils, each containing about 1% SASH and having TBN
levels of lo and 9, respectively, whPrein each formulated oil contained overbased metal detergent together with a zinc-source.
J. A. McGeehan, SAE Paper No. 831721, pp.
4.848-4.869 (1984) summarized the results of a series of heavy duty diesel engine tests to investigate the effect of top land deposits, fuel sulfur and lubricant viscosity on diesel engine oil consumption and cylinder bore polishing.
These authors also indicated that excessive top land deposits cause high oil consumption and cylinder bore polishing, although they added that cylinder bore polishing is also caused in high sulfur fuels by corrosion in oils of low alkalinity value. Therefore, they concluded that oil should provide sufficient alkalinity to minimize the corrosive aspect of bore polishing. The authors reported that an experimental 0.01% sulfated ash oil, which was tested in a AVL-Mack~WTZ675 ~turbocharged) 120-hour test in combination with a O .2% fuel sulur, provided minimum top land deposits and very low oil consumption, which was said to be clue to the "very effective ashless inhibitor".
This latter component was not further defined. Further, from the data presented by the author in Figure 4 of this Paper, there do not appeax to be oil consumption credits to reducing the ash level below 1~, since the oil consumption in the engine actually rose upon reducing the SASH from l to 0.01%. This reinforces the author's vi~w that a low, but significant SASH level is required for sufficient alkalinity to avoid oil consumption as a result of bore polishing derived from corrosive aspects of the oil.
McGeehan concluded that the deposits on the top land correlate with oil consumption but are not directly related to the lubricant sulfated ash, and commented that these deposits can be controlled by the crankcase oil formulation.

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1327~0 ,. g SU~Ma~OF THE INVENTION
In accordanc~ with the present invention, there are provided ashles3 heavy duty diesel lubricating oil csmpositions which comprise an oil of lubricating viscosity ~ as the major component and as the ~inor component (A) at lea~t 3 wt.% o~ a~ least one ashless dispersant, (B) at least 2 wt.% of at least one ~ulfurized alkyl phenol, and s ~C) at least O.l wt.% o~ at least one organo-sulfur compound of the formula ~- R4 - (S)w ~ C ~ (S)z R
': \S/
wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkylaryl or arylalkyl radicals having from 2 to about 30 carbon ato~s, and w and z ar~
number3 from 1 to about 8, wherein the lubricating oil is ; characterized by a total sulfated ash (SASH) level of less than O.Ol wt.%.
. The improved oil~ of the pre~ent invention are particularly useful in diesel engines powered by low sulfur fuels. ThQrefore, the present invention also provides a .method for i~proving the performance of a heavy duty diesel !,lubricating oil adapted for use in a diesel engine provided 'with a~ least one tight top land piston, and preferably furth~r adapt,ed ~or being powered by a normally liquid fuel ,:haYing a 3ul ~ur cont~nt of less than 1 wt.%, which f~comprises controlling the metal content of the oil to proYid~ a total sulfated ash (SASH) level in said oil of than O.Ol wt.%, and provlding in ~aid oil (A) at least about 3 wt.~ ashl~ss disper~ant, (B) at l~ast about 2 w~.%
;.~sulfurized alkyl phonol oxidation inhibitor, and (C) a copper corrosion inhibiting amount of at lea~t one organo-~ulfur compound of the formula R4 - ts~ - C /~ - (S)z - R5 S
wh-r-in R~ and R5 ar- utra1ghe or branched ch~in alkyl, ;

1327~50 cycli~, alicyclic, aryl, alkaryl or aralkyl radicals having from 2 to 30 carbon atoms, and w and z are numbers from 1 .:
to about 8.

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DE~AIh~L DES~RIPTION OF THE INVENTIoN
Co~ponent A
Ashless, nitrogen or ester containing dispersants useful in this invention comprise boron-free members selected from the group consisting of (i) oil soluble salt~, amides, imides, oxazolines and e.ters, or mix~ures thereof, of long chain hydrocarbon ~ubstituted mono and dicarboxylic acids or their anhydrides: (ii) long chain aliphatic hydrocarbon having a polyamine attached directly thereto; and (iii) Mannich condensation products formed by condensing about a molar proportion of long chain hydrocarbon substituted phenol with about 1 to 2 . 5 moles of formaldehyde and about 0.5 to 2 moles of polyalkylene polyamine; wherein said long chain hydrocarbon group in (i), (ii) and (iii) is a polymer of a C2 to C10, e.g., C2 to C5 monoolefin, said polymer having a number average molecular weight of about 300 to about 5000.
A(i) Nitrogen- or ester- containing ashless dispersants comprise members selected from the group consisting of oil soluble salt3, amides, imides, oxazolines and esters, or mixture~ thereof, of long chain hydrocarbon substituted mono and dicarboxylic acids or their anhydrides wherein said long chain hydrocarbon group is a polymer of a C2 to C10, e.g., C2 to C5, monoole~in, said polymer having a number average molecular weight of from about 700 to 5000.
The long chain hydrocarbyl substituted mono or dicarboxylic acid material, i.e. acid, anhydride, or ester, used in the dispersant includes long chain hydrocarbon, generally a polyolefin, substituted with an average of from .:, ~, .
., i 13273~
- 12 ~
about O . 8 to 2 . o, preferably from about 1. o to 1. 6, ~ . g., 1.1 to 1.3 moles, per mole o~ polyolefin, of an alpha or beta- unsaturated C4 to C10 dicarboxylic acid, or anhydride or ester thereof. Exemplary of such dicarboxylic acids, anhydrides and esters thereof are fumaric acid, itaconic acid, maleic acid, maleic anhydride, chloromaleic acid, dimethyl fumarate, chloromaleic anhydride, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, etc.
Preferred olefin polymers for reaction with the unsaturated dicarboxylic acidæ to form the dispersants are polymers comprising a major molar amount of C2 to C10, e.g. C2 to C5 monoole~in. Such olefins include ethylene, propylene, butylene, isobutylene, pentene, octene-1, styrene, etc. The polymers can be homopolymers such as polyisobutylene, aC well as copolymers of two or more of such olefins suoh as copolymers of: ethylene and propylene; butylene and isobutylene; propylene and isobutylene; etc. Other copolymers includ~ those in which a minor molar amount of the copolymer monomers, e.g., 1 to 10 mole ~, is a C4 to C18 non-conjugated diolefin, e.g., a copolymer of isobutylene and butadiene: or a copolymer of ethylene, propylene and 1,4-hexadiene; etc.
In so~e cases, the olefin polymer may be completely saturated, for example an ethylene-propylene copolymer made by a Ziegler-Natta synthesis using hydrogen as a moderator to control molecular weight.
The olefin polymers used in the dispersants will u~ually have number average molecular weights within the range of about 700 and about 5,000, more usually between about 800 and about 3000. Particularly useful olefin poly~ers have number average molecular weights within the range o~ about 900 and about 2500 with approximately one terminal double bond per polymer chain. An especially useful starting material for highly po~ent dispersant 1~273~

additives i~ polyisobutylene. The number average molecular weight for such polymers can be determined ~y several known techniques. A convenient method for such determination is by gel permeation chromatography (GPC) which additionally provides molecular weight distribution information, see W.
W. Yau, J.J. Kirkland and D~D. Bly, "Modern Size Exclusion Liquid Chromatography", John Wiley and Sons, New York, 1979.
Processes for reacting the ole~in polymer with the C4_10 unsaturated dicarboxylic acid, anhydride or ester are known in the art. For example, the olefin polymer and the dicarboxylic acid material may be simply heated together as disclosed in U.S. Patents 3,361,673 and 3,401,118 to cause a thermal "ene" reaction to take place.
Or, the 018fin polymer can be first halogenated, for example, chlorinated or brominated to about 1 to 8 wt. %, preferably 3 to 7 wt. % chlorine, or bromine, based on the weight of polymer, by passin~ the chlorine or bromine through the polyolefin at a temperature of 60 to 250~C, e.g. 120 to 160'C, for about 0.5 to 10, preferably 1 to 7 hours. The halogenated polymer may then be reacted with sufficient unsaturated acid or anhydride at 100 to 250C, u ually about 180~ to 235-r, for about 0.5 to 10, e.g. 3 to 8 hours, so the product ob~ai~ed will contain the desired number of moles of the unsaturated acid per mole of the halogenæted polymer. Processes of this general type are taught in U.S. Patents 3,087,436; 3,172,892; 3,272,7g6 and others.
Alternatively, the olefin polymer, and the unsaturated acid material are mixed and heated while adding chlorine to the hot material. Processes of this type are disclosQd in U.S. Patent~ 3,215,707; 3,231,587: 3,912,764:
4,110,349; 4,234,435: and in U.K. 1,440,219.
By the use of halogen, about 65 to 95 wt. % of the polyolefin, ~.g. polyisobutylene will normally react with the d1carboxylic acid r,aterlal. Upon carrying out a .~

13273~

thærmal raaction without the us~ of halogen or a catalys~ D
the~ usually only about S0 to 75 wt. % of the poly-i obutyl~ne will react. Chlorination helps increase the r~activity. For convenience, th~ aforesaid functionality ratio~ of dicarboxylic acid producing units to polyolefin, e.g., 0.8 to 2.0 , etc. are basad upon the total amount o~
polyolafin, that i8, the total of both the reacted and unreacted polyolefin, used to mak~ the product.
Ths dicarboxylic acid pro~ucing material can also be further reacted with amines, alcohols, including polyol~, amino-alcohols, etc., to for~ other useful dispersant additives. Thus, if the acid producing material i8 to b~ further reacted~ e.g., neutralized, then gener~lly a ~a~or proportion of at lea3t 50 percent of the acid unit~
up to all the acid units will he reacted.
Amine compounds useful as nucleophilic reactants for neutxalization of the hydrocarbyl substituted dicarboxylic acid materials include mono- and (praferably) polyamine~, most preferably polyalXylene polyamin~s, of about 2 to 60, preferably 2 to 40 (e.g. 3 to 20), total car~on atom~ and about 1 to 12, preferably 3 to 12, and most pra~erably 3 to 9 nitrogen atoms in the molecul~.
These amines may b~ hydrocarbyl amines or may be hydrccarbyl amines $ncluding other groups, e.g, hydroxy groups, alkoxy groups, amide group~, nitriles, i~idazoline groups, and the like. ~ydroxy amines with 1 to 6 hydroxy group~, pr~erably 1 to 3 hydroxy groups are particularly u~ful. PrQferred amines ar~ aliphatic saturated a~in~s, including those o~ the g~neral formulas:
R-N-R', and R-~ ~ CH2)8 - N-(CH2)s ~ N-R
~" R'~ ~''' J~ R' (I~ (II) wherein R, R', R'' and Rf ~ ~ ar~ independently selacted from the group con~isting of hydrog~n; Cl to C25 straight or branched chain alkyl radicals; Cl to C12 alkoxy C~ to .

. l327~a C6 alXylene radical~; C2 to C12 hydroxy amino alkylene radicals; and Cl to C12 alkylamino C2 to C6 alkylene radicals; and wherein R~ can additionally comprise a moiety of the formula:
(CH2)S~- N ~ H (III) ~t' R' wherein R' is as defined above, and wherein s and s~ can be the sa~e or a dif~erent number o~ from 2 to 6, preferably 2 to 4; and t and t' can be the same or different and are number-~ of fro~ O to 10, preferably 2 to 7/ and most preferably about 3 to 7, with the proviso that the sum of t and t' is not greater than 15. To assure a ~acile reaction, it is preferred that R, R~, R~, R~, s, s', t and t' be selected in a manner sufficient to provide the compounds of Formulas I and II with typically at least one primary or secondary amine group, preferably at least two primary or secondary amine group~. This can be achieved by selecting at least one of said R, R', R" or R''' groups to be hydrogen or by letting t in Formula IY be at least one when R"' i~ H or when the III moiety pos~esses a secondary amino ~roup. The ~ost preferred amine o~ the above for~ulas are represented by Formula II and contain at least two pri~ary amine groups and at lea~t one, and preferably at least thr~e, secondary amine groups.
Non-limiting examples o~ suitable amine compounds includ~: 1,2-diaminoethane; 1,3-diaminopropane;
1,4-diaminobutane: 1,6-diaminohexane; polyethylene amines ~uch as diethylene triamine; triethylene tetramine;
tetraethylene pentamine; polypropylene amines such as 1,2-propylene dia~ine; di-(1,2-propylene)triamine:
di-(1,3-propylene) triamine; N,N-dimethyl-1,3-diamino~
propane; N,N-di-(2-aminoethyl) ethylene diamine;
N,N-di(2-hydroxyethyl)-1,~-pxopylene dia~ine; 3-dodecyloxy-propyla~ine; N-dodecyl 1,3-propane diamine; tris hydroxy-.
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-` 1327~0 methylaminomethane (THAM); diisopropanol amine; diethanol amine; triethanol amine; mono-, di-, and tri tallow amines;
amino morpholines such as N-(3-aminopropyl)morpholine; and mixtures thereof.
Other useful amine compounds include: alicyclic diamines such as l~4-di(aminomethyl~ cyclohexane, and heterocyclic nitrogen compounds such as imidazolines, and N-aminoalkyl piperazines of the general formula (IV):

H{NH-(CH2)p ~ / ~ (cH2) _ NH }
nl CH2-CH2 n2 P2 n3 wherein Pl and P2 are the same or different and are each integers of from l to 4, and nl, n2 and n3 are the same or different and are each integers of from l to 3. Non-limiting examples of such amines include 2-pentadecyl imidazoline; N-(2-aminoethyl) pipera2ine; etc.
Commercial mixtures of amine compounds may advantageously be used. For example, one process for preparing alkylene amines involves the reaction of an alkylene dihalide (such as ethylene dichloride or propylene dichloride) with ammonia, which results in a complex mixture of alkylene amines wherein pairs of nitrogens are joined by alkylene groups, forming such ~ompounds as diethylene triamine, triethylenetetramine, tetraethylene pentamine and isomeric piperazines. Low cost poly(ethylenea~ines~ compounds averaging about 5 to 7 nitrogen atoms per molecule are available commercially under trade marks such as "Polyamine H", "Polyamine 400", "Dow Polyamine E-lOO", etc.
Useful amines also include polyoxyalkylene polyamines such as those of the formulae:
., ,, NH2 alkylene t O-alkylene ~ NH2 ~V) m ,, .~

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--`` 13273~0 where m has a value of about 3 to 70 and preferably 10 to 3s; and R ~ alkylene ~ O-alkylene ~ NH2 ) n a (VI) where "n" has a value of about 1 to 40 with the proYision that the sum of all the n's is from about 3 to about 70 and preferably from about 6 to about 35, and R is a polyvalent saturated hydrocarbon radical of up to ten carbon atoms wherein the number of substituents on the R group is represented by the value of "a", which is a number of from 3 to 6. The alkylene groups in either formula (V) or (VI~
may be straight or branched chains containing about 2 to 7, and preferably about 2 to 4 carbon atoms.
The polyoxyalkylene polyamines of formulas (V) or (VI) above, preferably polyoxyalkylene diamines and polyoxyalkylene triamines, may have average molecular weights ranging from about 200 to about 4000 and preferably from about 400 to about 2000. The preferred polyoxyal-kylene polyoxyalkylene polyamines include the polyoxyethylene and polyoxypropylene diamines and the polyoxypropylene triamines having average molecular weights ranging from about 200 to 2000. The polyoxyalkylene polyamines are commercially available and may be obtained, for example, from the Jefferson Chemical Company, Inc.
under the trade marks "Jeffamines D-230, D-400, D-1000, D-2000, T-403", etc.
The amine i5 readily reacted with the selected dicarboxylic acid material, e.g. alkenyl succinic anhydride, by heating an oil solution containing 5 to 95 wt. % of dicarboxylic acid material to about 100 to 250 C., preferably 125 to 175-C., generally for 1 to 10, e.g. 2 to 6 hours until the desired amount of water is removed. The heating is preferably carried out to favor formatlon of imides or mixtures of imides and amides, . ~
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rather than amides and salts. Reaction ratios of dicarboxylic material to equivalents of amine as well as the other nucleophilic reactants described herein can vary considerably, depending on the reactants and type of bonds ; formed. Generally from 0.1 to 1.0, preferably from about 0.2 to 0.6, e.g., 0.4 to 0.6, moles of dicarboxylic acid moiety content (e.g., grafted maleic anhydride content~ is used per equivalent of nucleophilic reactant, e.g., amine~
For example, about 0.8 mole of a pentaamine (having two ' primary amino groups and five equivalents of nitrogen per ; molecule) is preferably used to convert into a mixture of ''.J', amides and imides, the product formed by reacting one mole of olefin with sufficient maleic anhydride to add 1.6 moles of succinic anhydride groups per mole of olefin, i.e., preferably the pentaamine is used in an amount sufficient to provide about 0.4 mole (that is, 1.6 divided by (0.8 x 5) mole) of succinic anhydride moiety per nitrogen equivalent of the amine.
The nitrogen containing dispersants can be further treated by boration as generally taught in U.S. Patent Nos.
, 3,087,936 and 3,254,025. This is readily accomplished by ; treating the selected acyl nitrogen dispersant with a boron compound selected from the class consisting of boron oxide, boron halides, boron acids and esters of boron acids in an ;~ amount to provide from about 0.1 atomic proportion of boron for each mole of said acylated nitrogen composition to about 20 atomic proportions of boron for each atomic ` proportion of nitrogen of said acylated nitrogen composition. Usefully the dispersants of the inventive combination contain from about 0.05 to 2.0 wt. %, e.g. 0.05 to 0.7 wt. % boron based on the total weight of said borated acyl nitrogen compound. The boron, which appears ~' to be in the product as dehydrated boric acid polymers (primarily (H~02)3), is believed to attach to the ) 327~n ~ 19 -di~persant imides and dii~ides as amine salts, e.g., the m~taborate salt of aid diimide.
Treating is readily carried out by adding from about O.05 to 4, e.g. 1 to 3 wt. % (based on the weight of said acyl nitrogen co~pound) of said boron compound, preferably boric acid which i~ ~o~t usually added as a slurry to said acyl nitrogen compound and heating with stirring at fro~ about 135C. to 190, e.g. 140-170~C., for from 1 to 5 hours follo~ed by nitrogen stripping at said temperature ranges. or, the boron tr~atment can be carried out by adding boric acid to the hot reaction mixture of the dicarboxylic acid ~aterial and amine while re~oving water.
The tris (hydroxymethyl3 amino methane (THAN) can be reacted with the aforesaid acid material to form amides, imides or ester type additives as taught by U.K. 984,409, or to form oxazoline compounds and borated oxazoline compounds as described, for example, in U.S. 4,102,798;
4,116,876 and 4,113,639.
The ashles~ dispersants may also be esters derived from the aforesaid long chain hydrocarbon substituted dicarboxylic acid material and from hydroxy compound~ such as monohydric and polyhydric alcohols or aromatic co~pounds such as phenols and naphthols, etcO The polyhydric alcohols are the most prsferred hydroxy compound and preferably contain ~rom 2 to about 10 hydroxy radicals, for exa~pls, ~thylene glycol, diethylene glycol, triethylene glycol, tetr~ethylene glycol, dipropylene glycol, and other alkylene glycols in which the alkylene radical contains ~ro~ 2 to about 8 carbon ato~s. Other useful polyhydric alcohc~ls include glycerol, mono-oleate of glycerol, monostearate of glycerol, monomethyl ether of glycerol, pentaerythritol, dipentaerythritol, and mixtures thersof.
The ester disper~ant ~ay also be derived fro~
unsaturated alcohols such a~ allyl alcohol, cinnamyl alcohol, propargyl alcohol, l-cyclohexane-3-ol, and oleyl alcohol. Still other cla~e~ of the alcohols capable of ~L~273~

yielding the esters of this invention comprise the ether-alcohols and amino-alcohols including, for example, the oxy-alkylene, oxy-arylene-, amino-alkylene-, and amino~arylene-substituted alcohols having one or more oxy-alkylene, amino-alkylene or amino-arylene oxy-arylene radicals~ They are exemplified by Cellosolve, Carbitol, N,N,N',N'-tetrahydroxy-trimethylene di-amine, and ether-alcohols having up to about 150 oxy~alkylene radicals in which the alkylene radical contains from 1 to about 8 carbon atoms.
The ester dispersant may be di-esters of succinic acids or acidic esters, i.e., partially esterified succinic acids; as well as partially esterified polyhydric alcohols or phenols, i.e., esters having free alcohols or phenolic hydroxyl radicals. Mixtures of the above illustrated esters likewise are contemplated within the scope of this invention.
The ester dispersant may be prepared by one of several known methods as illustrated for example in U.S.
Patent 3,381,022. The ester dispersants may also be borated, similar to the nitrogen containing dispersants, as described above.
Hydroxyamines which can be reacted wi~h the aforesaid long chain hydrocarbon substituted dicarboxylic acid materials to form dispersants include 2-amino-1-bu-tanol, 2 amino-2-methyl-1-propanol, p-(beta-hydroxy-ethyl)-aniline, 2-amino-1-propanol, 3-amino-1-propanol, 2-a~ino-2-~ethyl-1, 3-propane-diol, 2-amino-2-ethyl-1, 3-propanediol, N-(beta-hydroxy-propyl)-N'-(beta-amino-ethyl)-piperazine, tris(hydroxymethyl) amino-methane (also known as trismethylolaminomethane), 2-amino-1-butanol, ethanolamine, beta-(beta-hydroxyethoxy)ethylamine, and the like. Mixtures of these or similar amines can also be employed. The above description of nucleophilic reactants suitable for reaction with the hydrocarbyl substituted dicarboxylic acid or anhydride includes amines, alcohols, :`~
`t~
.

' ~, 13273~0 _ 21 -and compounds of mixed amine and hydroxy containing reactive functional groups , i . e ., amino-alcohols.
A preferred group of ashless dispersants are those derived from polyisobutylene substituted with succinic anhydride groups and reacted with polyethylene amines, e.g. tetraethylene penta~ine, pentaethylene hexamine, polyoxyethylene and polyoxypropyl~ne amines, e.g.
polyoxypropylene diamine, trismethylolaminomethane and pentaerythritol, and combinations thereof. one particularly preferred dispersant combination involves a combination of (i) polyisobutene substituted with succinic anhydride groups and reacted with (ii) a hydroxy compound, e.g. pentaerythritol, ~iii) a polyoxyalkylene polyamine, e.g. polyoxypropylene diamine, and (iv) a polyalkylene polyawine, e.g. polyethylene diamine and tetraethylene pentamine using about 3.3 to about 2 moles each of (ii) and (iv) and about 0.3 to about 2 moles of (iii) per mole of (i) as described in U.S. Patent 3,804,763. Another preferred dispersant combination involves the combination o~ (i) polyisobutenyl succinic anhydride with (ii) a polyalkylene polyamine, e.g. tetraethylene pentamine, and (iii) a polyhydric alcohol or polyhydroxy-substituted aliphatic primary amine, e.g. pentaerythritol or trismethylola~inomethane as described in U.S. Patent ~,632,511.
iiL Also useful as ashless nitrogen-containing disp~rsant in this invention are dispersants wherein a nitrog~n containing polyamine is attached directly to the long chain aliphatic hydrocarbon a3 shown in U.S. Patents 3,275,554 and 3,565,804 where the halogen group on the halogenated hydrocarbon is displaced with various alkylene polyamines.
Al~ Another class of nitrogen containing dispersants which way ba used are those containing Mannich base or ~annich conden~ation products as thay are known in the art. Such ~nnich condens~tlon producte gen-rally are 13~73~0 prepared by condensing about 1 mole of a high molecular weight hydrocarbyl substituted mono-or polyhydroxy benzene (e.g., having a number average molecular weight of 1,000 or greater) with about 1 to 2.5 moles of formaldehyde or paraformaldehyde and about 0.5 to 2 moles polyalkylene polyamine as disclosed, e.g., in U.S. Patents 3,442,808;
3,649,229 and 3,798,165. Such Mannich condensation products may include a long chain, high molecular weight hydrocarbon on the phenol group or may be reacted with a compound containing such a hydrocarbon, e.g., polyalkenyl succinic anhydride as shown in said aforementioned U.S.
Patent 3,442,808.
Component B
Component B of the compositions of this invention is at least one sulfurized alkyl phenol as oxidation inhibitor. Sulfurized alkyl phenols and the methods of preparing them are known in the art and are disclosed, for example, in the following U.S. Patents: 2,139,766;
2,198,828; 2,230,542; 2,836,565; 3,285,854; 3,538,166;
3,844,956; and 3,951,830.
:
!, In general, the sulfurized alkyl phenol may ~e prepared by reacting an alkyl phenol with a sulfurizing agent such as elemental sulfur, a sulfur halide (e.g., sulfur monochloride or sulfur dichloride), a mixture of hydrogen sulfide and sulfur dioxide, or the like. The r, preferred sulfurizing agents are sulfur and the sulfur halide3, and especially the sulfur chlorides, with sulfur dichloride (SC12) being especially preferred.
,~ The alkyl phenols which are sulfurized to produce '~ component A are generally compounds containing at least one s~ hydroxy group and at least one alkyl radical attched to the same aromatic ring. The alkyl radical ordinarily contains about 3-100 and preferably about 6-20 carbon atoms. The , alkyl phenol may contain more than one hydroxy group as .~
x ,~. .:, ,.~

1327~.5~
- 23 _ exemplified by alkyl resorcinols, hydroquinones and catechols , or it may contain more than one alkyl radical;
but normally it contains only one of each. Compounds in which the alkyl and hydroxy groups are ortho, meta and para to each other, and mixtures of such compounds, are within the scope of the invention. Illustrative alkyl phenols are n-propylphenol, isopropylphenol, ~a-butylphenol, t-butylphenol, hexylphenol, heptylphenol, octylphenol, nonylphenol, n-dodecylphenol, (propene tetramer)-sub-~tituted phenol, octadecylphenol, elcosylphenol, polybutene (molecular weight about 1000)-substituted phenol, n-dodecylresorcinol and 2,4-di-t-butylphenol. Also included are methylene-bridged alkyl phenols of the type which may be prepared by the reaction of an alkyl phenol with formaldehyde or a formaldehyde-yielding reagent such as trioxane or paraformaldehyde .
The sulfurized alkyl phenol is typically prepared by reacting the alkyl phenol with the sulfurizing agent at a temperature within the range of about 100-250C. The reaction may take placs in a substantially inert diluent such as toluene, xylene, petroleum naphtha, mineral oil, Callosolve or th~ like. If the ~ulfurizing agent is a sulfur halide, and especially if no diluent is used, it is frequently pre~erred to remove acidic materials such as hydrogen halides by vacuum stripping the reaction mixture or blowing it with an inert gas such as nitrogen. If the sulfur~zing agent is sulfur, it is frequently advantageous to blow tha ~ul~urized product with an inert gas such as nitrogen or air 80 as to remove sulfur oxides and the like.
~ omlps7~ent ~
Component C of the present inventiQn is a copper corrosion inhibitor and comprises at least one hydrocarbon polysulfide derivative of 2, 5-dimercapto-1, 3, 4-thiadiazole having tho for~ula:

13273~

N - N

S
wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkylaryl or arylalkyl radicals having fro~ 2 to about 30 carbon atoms, and w and z are numbers from l to about 8. Preferably R4 and R5 each have from 4 to about 16 carbon atom~, and most preferably from about 8 to about 14 carbon atoms, and preferably the values of "w" and "z" are nu~bers of from 1 to 4.
.~ The herein-described polysulfide derivatives of 2,5-dimercapto-1,3,4-thiadia~ole can be suitably prepared by several methods. For example, they can be prepared by ~-~ reacting 2,5-dimercapto-1,3,4-thiadiazole with a suitable . sulfenyl chloride, or by reacting the dimercaptan with ~ chlorine and reacting the resultant disulfenyl chloride ;~ below ; N - N
. Cl - S - C C - S - Cl .'' \S/
with a primary or tertiary mercaptan. Bis-trisulfide derivative~ are obtained by reacting the dimereaptan with a mercaptan ancl a sulfur chloride in molar ratios of from 1:2:2 to 1:2:4 at a temperature of from about 120 to 212-F. Higher poly ulfides may be prepared by reacting the thiadiazole di- or trisulfides with sulfur at temperatures of about 200-F to 400-F. Another method of preparing the poly~ulfide~ of the present invention involves reacting 2,5-dimercapto-1,3,4- thiadiazole with a mercaptan and sulfur in the molar ratio of from 1:1:1 to 1:4:16 at temp~ratures of from about 160^F to about 300-F.
Compounds produced in accordance with the above p ro c e d u r2 p re fe r~ bl y a re p ol y s u l f i d e s o f 1,3,4-thiadiazole-2,5-bis(alXyl, di-tri or tetra sulfide) containing rro~ 2 to about 30 carbon ato~s. Desirable ;

`` ~3~73~0 polysulfides include 1,3,4-thiadiazole-2,5-bis (octyldisulfide); 1,3,4-thiadiazole-2,5-bis(octyl-trisulfide); 1,3,4-thiadiazole-2,5-bis toctyltetrasulfide), 1,3,4-thiadiazole-2,5-(nonyldisulfide); 1,3,4-thia-diazole-2,5-(nonyltrisulfide); 1,3,4-thiadiazole-2,5-~nonyl-tetrasulfide); 1,3,4-thiadiazole-2,5-bis(dodecyldisulfide);
1,3,4-thiadiazole-2,5-bis(dodecyltrisulfide); ~,3,4-thiadia-zole-2,5-bis(dodecyltetrasulfide: 2-lauryldithia-5-thiaal-phamethylstyryl-1,3,4-thiadiazole and 2-lauryl-trithia-5-thiaalphamethylstyryl-1,3,4-thiadiazole and mixtures thereof. Preferred materials are the derivatives of 1,3,4-thiadiazoles such as those described in U.5.
Patents 2,?19,125; 2,?19,126; and 3,087,932; especially preferred is the compound 2,5-bis (t-octadithio)-1,3,4 thiadiazole commercially available as Amoco 150, and 2,5-bis(nonyldithio)-1,3,4-thiadiazole, commercially available as Amoco 158.
Preparation of Component C is further described in U.S. Patents 2,719,125; 2,719,126; 3,087,932; and 4,410,436.
!~
'.~.

~.~

: ';
::`
, , .

'.
`~ , - 13273~G

LUBRICATING CO~PQ~TIONS
Lubricating oil compositisns, e.g. automatic transmi~sion fluids, heavy duty oils suitable for diesel engine~ (that is, compression ignition engines)~ etc., can : be prepared with the additives of the invention. Universal type crankcase oils wherein the sa~e lubricating oil co~positions can be u ed for both gasoline and diesel engine can also be prepared. TheQe lubricating oil for~ulations conventionally contain several different types of additives that will supply the characteriatics that are required in the formulations. A~ong these types of additives are included viscosity index improvers, ashless antioxidants, ashless corrosion inhibitors, pour point depressant~, ashless antiwear agents, etc., provided the ~ully formulated oil satisfies the ashleæs SASH
: reguirements of this invention.
In the preparation of heavy duty diesel lubricating oil formulations it is common practice to introduce the additives in th2 form of 10 to 80 wt. %, e.g.
20 to 80 wt. % active ingredient concentrates in hydrocarbon oil, e.g. mineral lubricating oil, or other . suitable solvent. Usually these concentrates may be diluted with 3 to 100, e.g. 5 to 40 parts by weight of lubricatin~
oil, per ~art by weight of the additive package, in for~ing finished lubricants, e.g. crankcase motor oils. The purpose of concentrates, of course, is to make the handling o~ the various materials less difficult and awkward as well a~ to facilitate solution or dispersion in the final blond. Thus, a Component A ashless dispersan~ would be usually e~ploy~d in the form oP a 40 to 50 wt. %
concentratQ, for example, in a lubricating oil fraction.
{ Components A, ~ and C of the present invention will b~ g~nerally used in admixture with a lube oil ba~estoc~, co~pri ing an oil of lubricating viscosity, including natural and synthatic lubricating oils and ixtur s th-r~o~.

.
., _ 27 -Components A, B and C can be incorporated into a lubricating oil in any convenient way. Thus, these mixtures can be added directly to the oil by dispersing or dissolving the same in the oil at the desired level of concentrations of the detergent inhibitor and antiwear agent, respectively. Such blending into the additional lube oil can occur at room temperature or elevated temperatures. Alternatively, the Components A, B and C can be blended with a suitable oil-soluble solvent and base oil to form a concentrate, and then blending the concentrate with a lubricating oil basestock to obtain the final formulation. Such concentrates will typically contain (on an active ingredient (A.I.) basis) from about 10 to about 70 wt. %, and preferably from about 30 to about 60 wt. %, Component A ashless dispersant additive, typically from about 10 to 40 wt. %, preferably from about 10 to 30 wt. ~
Component B antioxidant additive, typically from about 0.5 to 5 wt.~, and prefsrably fro~ about 0.6 to 3 wt.~, Component C copper corrosion inhibitor, and typically from about 30 to 80 wt. %, preferably from about 40 to 60 wt. %, base oil, based on the concentrate weight.
The composition~ of this invention are also characterized a3 being ashless, that is, by a total sulfate ash value (SASH) concentration of less than 0.01 wt.% SASH, preferably ~ub~tantially zero. By l'total sulfated ash"
herein is mean~ the total weight % of ash which is determined for a given oil (based on the oil's metallic co~ponents) by ASTM D874.
The lubricating oil basestock for Components A, B
and C typically i8 adapted to perform a selected f~nction by the incorporation o~ additional additives therein to form lubricating oil co~po~itions (i.e., formulations~.
Natural oils include animal oils and vegetable oils (e.g., castor, lard oil) liquid petroleu~ oils and hydrorefined, solvent-treated or acid-treated mineral lubricating oil~ of the paraffinic, naph~henic and mixed .t32~3~

paraffinic naphthenic types. Oils of lubricating viscosity derived froD coal or shale are also u~eful base oils.
A13cylene oxide polymers and interpolymers and darivatives thereof where the terminal hydroxyl groups have been ~odified by esterification, etherification, etc., constitute another clas~ of known synthetic lubricating oils. These are exemplified by polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide, the alkyl and aryl eth~rs of these polyoxyalkylene polymers (e.g., ~ethyl-poly isopropylene glycol ether having an average molecular weiqht of 1000, diphenyl ether of poly-ethylene glycol having a Molecular weight of 500-1000, diethyl ether of polypropylene glycol having a ~olecular weight of 1000-1500); and mono- and polycarboxylic esters thereof, for example, the acetic acid esters, mixed C3-C8 fatty acid estQrs and C13 Oxo acid diester of tetraethylene glycol.
Another suitable class of synthetic lubricating oils comprises the esters of dicarboxylic acids (e.g., phthalic acid, succinic acid, alkyl succinic acids and alkenyl succinic acids, maleic acid, azelaic acid, suberic acid, sebasic acid, fumaric acid, adipic acid, linoleic acid dim~r, malonic acid, alkylmalonic acids, lkenyl ~alonic acids) with a variety of alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ~thyl~n~ glycol, diethylene glycol monoether, propylene glycol). Specific example of these esters includ~ dibutyl adipate, di(2-ethylh~xyl)sebacate, di-n-h~xyl fumarat~, dioctyl sebacate, diisooctyl azelate, dii~od~cyl azelate, dioctyl phthalate, didecyl phthalate, dieicosyl sebacate, the 2-ethylhexyl diester of linoleic acid dimer, and the complex ester formed by reacting one mole of sebacic acid with two moles of tetraethylene glycol and two mçle~ of 2-ethylhQxanoic acid.
Esters useful as synthetic oils also include those ~ade from C5 to C12 monocarboxylic acid~ and polyols .
;

13273~ ~

and polyol ethers such a~ neopentyl glycol, triDIethylol-propane, pentaerythritol, dipsntaerythritol and tripentaerythritol.
Silicon-ba~ed oil9 such as the polyalkyl-t polyaryl-, polyalkoxy-, or polyaryloxysiloxane oils and silicate oils compri e another u~eful class of ~ynthetic lubricants: they include tetraethyl silicate, tetraisopropyl silicate, tetra-(2-ethylhexyl) silicate, tetra-(4-~ethyl-2-ethylhexyl) silicate, tetra-(p-tert-butylphenyl) ~ilicate, hexa-(4-methyl-2-pentoxy) disiloxane, poly(methyl) siloxanes and poly(methylphenyl) siloxanes. Other synthetic lubricating oil~ include liquid esters of phosphorus-containing acids (e.g., tricresyl pho~phate, trioctyl phosphate, diethyl e~ter o~
decylphosphonic acid) and polymeric ~etrahydrofuran~.
Unrefined, refined and rerefined oils can be used in the lubricant3 of the present invention. Unrefined oils are those obtained directly from a natural or synthetic source without further purification treatment. For example, a ~hale oll obtainad directly from retorting operations, a petroleu~ oil obtained directly from distillation or e~ter oil obtained directly ~rom an esterification process and used without ~urther treatment would be an unrefined oil. Refined oils are similar to the unrefined oils except they have been further treated in one or more purif~cation ~taps to improve one or more propertias. ~any such pu~ification ~echniques, such as di~till~tion, solvent extraction, acid or base extraction, filtration and percolation are known to those skilled in the art. Rere~ined oils are obtained by processes ~imilar to thoso used to obtain re~inQd oil~ applied to refined oils which have bQen alr~ady used in service. Such rerafined oil~ are al~o known as reclaimed or reprocessed oils and often are additionally processed by tech~iques for r~moval of ~pent additiYes and oil breakdown products.
~h~ nov-l corpoo1eion~ Or th- pr~-nt lnv~ntion ;.

13273~0 can b~ used with V.I improvers to form multi grade diesel enqinQ lubri~ating oils. vi~c08ity modifiers impart high and low t~mperature operability to the lubricating oil and permit it to remain relatively viscous at elevated te~perature~ and al~o exhibit acceptable viscosity or fluidity at low temperatures. Viscosity modiiers are generally high molecular weight hydrocarbon polymers including polyesters. The viscosity modifiers may also be darivatized to include other propertie~ or functions, such as the addition of dispersancy properties~ These oil soluble viscosity modifying poly~ers will generally have numb~r average molecular weights of from 103 to 106, prererably 104 to 106, e.g., 20,000 ~o 250,000, as determined by gPl permeation chromatography or osmometry.
Exampl~ of suitable hydrocarbon polymers include homopolymers and copolymers o~ two or more monomers of C2 to C30, e.g. C2 to C8 olefins, including both alpha ole~ins and internal olefin~, which may be straight or branched, aliphatic, aromatic, alkyl-aromatic, cycloaliphatic, etc. Frequently they will be of ethylene with C3 to C30 ol~fins, particularly preferred being th~ copoly~ers of ethylene and propylene. Other polymers can be used such a~ polyisobutylenes, homcpolymers and copolymer~ o~ C6 and higher alpha olsfins, atactic polypropylen~, hydrogenated polymers and copolymers and terpolymer~ o~ styrene, e.g. with isoprene and/or butadiene and hydroqenated d~rivatives thereof. The pol~mer may be dqgrad~d i~ molecular weight, for ~xample by mastication, ~xtrusion, oxidation or thermal degradation, and it may be oxidiz~d and contain oxygen. Also included are d~rivatized poly~ers such as post-gra~ted interpolymarc of ethylen~-propylene with an active monomer ~uch as maleic anhydride which ~ay b~ further reacted with an alcohol, or amine, e.g. an alkylene pclyamine or hydroxy amina, e.g.
sQe U.S. Patent No~. 4,0~9,794; 4,160,739; 4,137,185; or .

.

f .~

: 13273~

: - - 31 -copolymers of ethyl~ne and propylene reacted or grafted with nitrogen compounds such as shown in U.S. Patent Nos.
4,068,056: 4,068,058; 4,146,489 and 4,149 t 984O
~;; Th2 preferred hydrocarbon pol~ners are ethylene copolyners containing from 15 to so wt. ~ ethylene, prsferably 30 to 80 wt. % of ethylene and 10 to 85 wt. %, preferably 20 to 70 wt. % of one or more C3 to c28, preferably C3 to C18, ~ore preferably C3 to c8, alpha-olefins. While not e~sential, such copolymers preferably have a degree of crystallinity of less than 25 wt. %, as determined by X-ray and differential scanning calorimetry. Copolymers of ethylene and propylene are most preferred. Other alpha-ole~ins suitable in place of propylene to form the copolymer, or to be used in combin-ation with ethylene and propylene, to for~ a terpolymer, tetrapoly~er, etc. , include l-butene, l-pentene, l-hexene, l-heptene, l-octene, l-nonene, 1-decene, etc.: also branched chain alpha-ol~fins, such as ~-methyl-l-pentene, 4-methyl-1-hexene, 5-methylpentene-1, 4,4-di-methyl-l-pentene, and 6-methylheptene-1, etc., and mixtures ` thereof.
- Terpoly~ers, tetrapolymer~, etc., of ethylen~, said C3-C28 alpha-olefin, and a non-conjugated diolefin or mixtures og such diolefins ~ay al50 be used. The amount of the non-conjugated diolefin generally ranges from about 0.5 to 20 ~ol~ percent, preferably fro~ about 1 to about 7 mole percent, based on the total amount of ethylene and alpha-ol~in pre~ent.
The polyester V.I. improvers are genarally polym~rs of esters of ethylenically unsaturated C3 to C8 ~ono- and dic~rboxylic acid~ such as methacrylic and acrylic acids, mal~ic acid, maleic anhydride, fum~ric acid, etc.
Example~ of unsaturat~d esters that may be used include those of aliphatic saturated ~ono alcohols of at l~ast 1 carbon ato~ and pr~exably of from 12 to 2G car~o~

- 13273~

atom~, such as decyl acrylate, lauryl acrylate, stearyl acrylate, eicesanyl acrylate, docosanyl aGrylate, decyl methacrylate, dia~yl fumarate, lauryl methacrylate, cetyl methacrylate, stearyl methacrylate, and the like and mixtures thereo~.
:~:
Other esters include the vinyl alcohol esters of C2 to c22 fatty or mono carboxylic acids, preferably saturated such as vinyl acetate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, and the li~e and ~ixturQs thereof. Copolymers of vinyl alcohol esters with unsaturated acid esters ~uch as the copolymer of vinyl acetate with dialkyl fumarates, can also be used.
The ester may be copolymerized with still other unsaturated monomers such as olefins, e.g. 0.2 to 5 moles f C2 ~ C20 aliphatic or aromatic olefin per mole of un~aturated ester, or per mole of unsaturated acid or anhydride followed by e-~terification. For example, copslymers of styrene with maleic anhydride esterified with alcohol~ and amines are known, e.g., see U.5. Patent 3,702,30~.
Such ester polymers may be grafted with, or the ester copolymerized with, polymerizable unsaturated nitrogen-containing monomers to impart dispersancy to the V.I. improvers. Examples of suitable unsaturated nitrogen-containing monomers include those containing 4 to 20 carbon atoms ~uch as amino substituted olefins as p-(beta-diethyl~minoethyl)styrene: basic nitrogen-con-taining heterocycles carrying a poly~erizable ethylenically un~aturated ~ubstituent, e.g. the vinyl pyridine~ and the vinyl alkyl pyridineR such as 2-vinyl-5-ethyl pyridine, 2-methyl-5-vinyl pyridine, 2-vinyl-pyridine, 4-vinyl-pyridine, 3-vinyl-pyridine, 3-methyl-5-vinyl-pyridine, 4-methyl-2-vinyl-pyridine, 4-ethyl-2-vinyl-pyridine and 2-butyl-1-5-vinyl-pyridine and the liken N-vinyl lactams are also suitable, e.g. N-vinyl pyrrolidono~ or N-vinyl piporidon~s.

1~27~
_ 33 -The vinyl pyrrolidones are preferred and are ex~mpliried by N-vinyl pyrrolidone~ N-(1-methylvinyl) pyrrolidone, N-vinyl-5 methyl pyrrolidone, N-vinyl-3, 3-di~ethylpyrrolidone, N-vinyl-5-ethyl pyrrolidone, etc.
Other antioxidants useful in thi~ invention include oil soluble copper compounds. The copper may be blended into the oil as any suitable oil soluble copper compound. By oil soluble W2 mean the compound is oil soluble under normal blending conditions in the oil or additive package. The copper coDIpound may be in the cuprous or cupric form. The copper may be in the form of the copper dihydrocarbyl thio- or dithio-phosphates wherein copper may be substituted for zinc in the coDIpounds and reactions described above although one mole of cuprous or cupric oxide may be reacted with one or two moles of the dithiophosphoric acid, respectively. Alternatively the copper may be added as the copper salt of a synthetio or natural carboxylic acid. Examples include C10 to C18 fatty acids such as stearic or palmitic, but unsaturated acids such as oleic or branched carboxyl ic acids such as naphthenic acids Or molecular weight froDI 200 to 500 or synthetic carboxylic acids are preferred because of the improved handling and solubility properties of the re~ulting copper carboxylates. Also useful are oil soluble copper dithiocarbamates of the general formula (RR'NCSS)nCu, where n is 1 or 2 and R and R' are ths same or different hydrocarbyl radicals containing from 1 to 18 and preferably 2 to 12 carbon atoms and including radicals such as alkyl, al~nyl, aryl, aralkyl, alkaryl and cycloaliphatic radicals. Particularly preferred as R and R' groups are alkyl groups of 2 to 8 carbon atoms. Thus, the radical~ may, for example, be ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, amyl, n-hexyl, i-hexyl, n heptyl, n-octyl, decyl, dodecyl, octadecyl, 2-ethylhexyl, phenyl, butylph~nyl, cyclohexyl, methylcyclopentyl, propenyl, butenyl, ~tc. In order to obtain oil solubility, ,:
~' ~327~5~

th~ total number of carbon atom~ (i.e, R and R') will genorally be about 5 or greater. Copper sulphonates;
phenates, and acetylacetonates may also be used.
Exemplary of useful copper co~pounds are copper CuI and/or CuII) salts of alkenyl succinic acids or anhydrides. The salts themselvas may be basic, neutral or acidic. They may be ormed by reacting (a) any of the material~ di~cussed above in the Ashless Dispersant section, which have at least one free carboxylic acid (or anhydride) group with (b) a reactive metal compound.
Suitable acid (or anhydride) reactive metal compounds include those such as cupric or cuprous hydroxides, oxides, acetates, borates, and carbonates or ba ic copper carbonate.
Examples of the metal salts of this invention are Cu salts of polyisobutenyl succinic anhydride (hereinafter referred to as Cu-PIBSA), and Cu salts of polyisobutenyl succinic acid. Preferably, the selected metal employed is it~ divalent ~orm, e.g., Cu+2. The pre~erred substrates are polyalkenyl succinic acids in which the alkenyl group has a number average molecular weight (Mn) greater than about 700. The alkenyl group desirably has a Mn from about 900 to 1400, and up to 2500, with a Mn f about 950 being most preferred. Especially preferred, of those l$stad abov6 in the section on Dispersants, is polyisobutylene succinic acid (PIBSA). These materials may d~irably b~ dissolved in a solvent, such as a mineral oil, and hoat~d in ~he presence of a water solution (or slurry) o~ tho m~tal bearing material. Heating may take place b~tws~n 70- and about 200-C. Temperatures of 110~ to 140-C
ar~ entirely ad~quate. It ~ay bs necessary, depending upon the salt produced, not to allow th~ reaction to remain at a temperature above about 140-C for an extended period of ti~e, e.g., longer than 5 hours, or decompoRition of tha salt may occur.
The copper antioxidants (e.g.t Cu-PIBSA, ;

13273~

Cu-oleate, or mixtures thereof) will be generally employed in an amount of from about 50-500 ppm by weight of the metal, in the final lubricating or fuel co~position.
The copper antioxidant~ used in this invention are inexpensive and are effective at low concentrations and therefore do not add cubstantially to the cost of the product. The re~ults obtained are frequently better than those obtained with previously used antioxidants, which are expensive and used in higher concentrations. In the amounts e~ployed, the copper compounds do not interfere with the performance of other components of th~ lubricating composition.
While any effective amount of the copper antioxidant can be ncorporated into the lubricating oil composition, it is contemplated that such effeztive amounts be sufficient to provide said lube oil co~position with an amount of the copper antioxidant of from about 5 to 500 (more preferably 10 to 200, still more pre~erably 10 to 180, and ~ost preferably 20 to 130 (e.g., 90 to 120)) part per million of added copper based on the weight of the lubricating oil composition. Of course, the preferred amount may depend amongst other factors on the ~uality of the basestock lubricating oil.
Corro~ion inhibitors, also known as anti-corrosive agent~, reduce the degradation of the non-ferrous metallic parts contacted by the lubricating oil composition.
Illustrativ~ of corrosion inhibitors are phosphosulfurized hydrocarbon~ and the products obtained by reaction of a pho~phosulfurized hydrocarbon with an alkaline earth metal oxidc sr hydroxide, preferably in the presence of an alkylated phenol or of an alkylphenol thioester, and also pr~ferably in the presence of carbon dioxide.
Phosphosulfurized hydrocarbons are prepared by reacting a suitablQ hydrocarbon such as a terp~ne, a heavy petroleum fraction o~ a C2 to C6 ol~fin polymer such as polyisobutylene, with ~rom S to 30 weight percent of a l3~73~a - 36 ~
sulfid~ of pho~phoruY for 1/2 to 15 hours, at a te~perature in th~ range of 65- to 320'C. Neutralization of the phospho~ul~urized hydrocarbon may be efected in the manner taught in U.S. Patent No. 1,969,324.
Othsr oxidation inhibitors can also be employed in addition to Component B, to assist, where desired, in further reducing the tendency of the ~ineral oils to deteriorate in service and to th~reby reduce the formation of product~ of oxidation such as sludge and varnish-like deposits on the metal surfaces and to reduce viscosity growth. Such other oxidation inhibitors include alkaline earth metal ~alts of alkylph~nolthioesters having preferably C5 to C12 alkyl side chains(such as calcium nonylphenol sulfide, barium t-octylphenyl ~ulfide, etc.), diphenyl amine, alkyl diphenyl amine~, dioctylphenylamine, phenyl alpha-naphthyla~ine (and its alkylated derivatives), pho~phosulfurized hydrocarbons, other sulfurized hydrocarbons (such as sulfurized phenols, sulfurized alkyl catechols, and the like), phenols, hindered-phenols, bis-phenols, catechol, alkylated catechols, etc.
Friction modifiers serve to impart the proper friction characteristics to lubricating oil compo~itions such as auto~atic transmission fluids.
R~pr~entative examples of suitable friction modifiers are found in U.S. Patent No. 3,933~659 which disclo~es fatty acid esters and amides; U.S. Patent No.
4,176,074 which de~cribes molybdenum complexe~ of polyiso-buSsnyl ~uccinic anhydride-amino alkanols: U.S. Patent No.
4,105,571 which discloses glycerol esters of dim~rized fatty acids; U.S. Patent No. 3,779,928 which discloses alkane phosphonic acid salts: U.S. Patent No. 3,778,375 which di~closes reaction products of a phosphonat~ with an olea~ide; U.S. Patent No. 3,852,205 which discloses S-carboxy-alXyl~n~ hydrocarbyl succinimide, S-carboxy-alkylene hydrocarbyl succina~ic acid and mixture~ ther~of;
U.S. Pat-ne No. 3,879,306 which d1sclD~3e~ N-(hydroxy--` 13273~

alkyl) alkenyl-succinamiC acids or succinimides; U.s.
Patent No. 3,932,290 which discloses reaction products of di-(lower alkyl) phosphites and epoxides; and U.s. Patent No. 4,028,258 which discloses the alkylene oxide adduct of phosphosulfurized N-(hydroxyalkyl) alkenyl succinimides.
The most preferred friction modifiers are glycerol mono and dioleates, and succinate esters, or metal salts thereof, of hydrocarbyl substituted succinic acids or anhydrides and thiobis alkanols such as described in U.S. Patent No.
4,344,853.
Pour point depressants lower the temperature at which the fluid will flow or can be poured. Such depressants are well known. Typical of those additives which usefully optimize the low temperature fluidity of the fluid are C8-C18 dialkylfumarate vinyl acetate copolymers, polymethacrylates, and wax naphthalene.
Foam control can be provided by an antifoamant of th~ polysiloxane type, e.g. silicone oil and polydimethyl siloxane.
organic, oil-soluble compounds useful as rust inhibitors in this invention comprise nonionic surfactants such as polyoxyalkylene polyols and esters thereof, and anionic surfactants such as salts of alkyl sulfonic acids.
Such anti-rust compounds are known and can be made by conventional means. Nonionic surfactants, useful as anti-rust additives in the oleaginous compositions of this invention, usually owe their surfactant properties to a nu~ber of weak stabilizing groups such as ether linkages.
Nonionic anti-rust agents containing ether linkages can be made by alkoxylating organic substrates containing active hydrogens with an excess of the lower alkylene oxides (such as ethylene and propylene oxides) until the desired number of alkoxy groups have been placed in the molecule.
The preferred rust inhibitors are polyoxyalXylene polyols and derivatives thereof. This class of aaterials ;

.` .

- 38 - 13~3~
are commercially available from various sources: Pluronic PolyolsT~from Wyandotte Chemicals Corporation; Polyglycol 112-2T~ a liquid triol derived from ethylene oxide and propylene oxide available from Dsw Chemical co.; and r~l Tergitol, dodecylphenyl or monophenyl polyethylene glycol ethers, and Ucon, polyalkylene glycols and derivatives, both available from Union Carbide corp. These are but a few of the commercial products suitable as rust inhibitors in the improved composition of the present invention.
In addition to the polyols per se, the esters thereof obtained by reacting the polyols with various carboylic acids are also suitable. Acids useful in preparing these esters are lauric acid, stParic acid, succinic acid, and alkyl- or alkenyl-substituted succinic acids wherein the alkyl-or alkenyl group contains up to about twenty carbon atoms.
The preferred polyols are prepared as block polymers. Thus, a hydroxy-substituted compound, R-(OH)n (wherein n is 1 to 6, and R is the residue of a mono- ox polyhydric alcohol, phenol, naphthol, etc.) is reacted with propylene oxide to form a hydrophobic base. This base is then reacted with ethylene oxide to provide a hydrophylic portion resulting in a molecule having both hydrophobic and hydrophylic portions. The relative sizes of these portions can be adjusted by regulating the ratio of reactants, time of reaction, etc., as is obviou~ to those skilled in the art. Thus it i5 within the skill of the art to prepare polyol~ whose molecules are characterized by hydrophobic and hydrophylic moieties which are present in a ratio rendering rust inhibitors suitable for use in any lubricant composition regardless of differences in the base oils and the presence of other additives.
If more oil-solubility is needed in a given lubricating composition, the hydrophobic portion can be increased andjor the hydrophylic portion decreased. If greater oil-in-water emulsion breaking ability is required, , ,~
, ., ~

~ 32~3~
~ 39 - .
the hydrophylic and/or hydrophobic portions can be adjusted to accompl ish this .
Co~pounds illustrative of R- (OH) n include alkylene polyols such a~ the alkylene glycol , alkylene triols, alkylene tetrols, etc., such a~ ethylene glycol, propylene glycol, glycerol, pentaerythritol, sorbitol, mannitol, and the like. Aromatic hydroxy compounds such as alkylated mono- and polyhydric phenols and naphthols can also be used, e.g., h~ptylphenol, dodecylphenol, etc.
Oth~r suitable demulsifi~rs in~lude the esters disclosed in U.S. Patents 3,098,827 and 2,674,619.
The liguid polyols available fro~ Wyandotte Chemical Co. under the name Pluronic Polyols and other similar polyol~ are particularly well suited as rust inhibitors. Thes2 Pluronic Polyols correspond to the formula:
H0 (CH2cH2o)x(cHc~2o)y(cH2cH2o)zH (VIII

wherein x,y, and z are întegers greater than 1 such that the --CH2CH20--groups comprise from about 10% to about 40% by weight of the total molecular weight of the glycol, the av~rage molecule weight of said glycol being from about 1000 to about 5000. These products are prepared by first condensing propylene oxide with propylene glycol to produce the hydrophobic base Ho(-cH-cR2-o)y-H (IX) Thi~ cond2nsation product is then treated with ethylene oxid~ to add hydrophylic portions to both ends o~ th~
molecule. For best results, the ethylene oxide unit~
should compri~e ~rom about 10 to about 40% by weight of the mol~cul~. Thos~ products whQrein the molecular weight of the polyol is from about 2500 to 4S00 and th~ ethylene oxide unit~ compris~ ~rom about 10% to about 15% by weight o~ th~ mol~cul~ are particularly suitabla. Th6 polyols ha~ing a molecular weight of about 4000 with about 10~

13273~Q

attributahle to (CH2CH2O) units are particularly good.
Also useful are alkoxylated fatty amines, amides, alcohols and the like, including such alkoxylated fatty acid derivatives treated with Cg to C~6 alkyl-substituted phenols (such as the mono- and di-heptyl, octyl, nonyl, decyl, undecyl, dodecyl and tridecyl phenols~, as described in U~S. Patent 3,849,501.
These compositions of our invention may also contain other additives such as those previously described, and other metal containing additives, for exa~ple, those containing barium and sodium.
Other suitable additives are the thio and polythio sulphenamides of thiadiazoles such as those described in U.X. Patent Specification 1,560,830. When these compounds are included in the lubricating co~position, we prefer that they be present in an amount from 0.01 to 10, preferably 0.1 to 5.0 weight percent based on the weight of the composition.
Some of these numerous additives can provide a multiplicity of effects, e.g., a dispersant-oxidation inhibitor. 'rhis approach is well known and need not be further elaborated herein.
Co~positions when containing these conventional additives are typically blended into the base oil in amounts ef~ective to provide their normal attendant function. Representative effective amounts of such additives (as the respective active ingredients) in the fully formulated oil are illustrated as follows:
:,, ;,~
~,.

.''' .~
~"
, '` ~

. .

"
., ~ ~3273~

Wt.% A~Io Wt~% A.I.
_ Compositions . ~Prefer~ed) (Broad Component A 4-7 3-10 Component B 2.2 4 2-6 Component C 0.2-0.4 0.1-0.6 Viscosity Modifiers 0 4 0-12 Other Corrosion Inhibitors 0.01-0.5 0-1.5 OthQr Oxidation Inh~bitors 0-1.5 0-5 Pour Point Depressants 0.01-0.5 .01-1.0 Anti-Foaming Agent~ 0.001-0.01 .001-0.1 Non-Metallic Anti-Wear Agents 0.001-1.5 0-5 Friction Nodifier~ 0.01-1.5 0-5 Lubricating 8as~ Oil Balance Balance When other additive~ are employed, it may be : .
desirable, although not nPcessary, to prepare additive concentrates comprising concentrated solutions or di~persions of the novel detergent inhibitor/antiwear agent mixtures of this invention (in concentrate amounts hereinabove described~, together with one or more of said other additives (said concentrate when constituting an additive mixture being referred to herein as an additive-package) whereby several additives can be added simultaneously to the base oil to form the lubricating oil composition. Dissolution of the additive concentrate into the lubricatinq oil may be facilitated by solvents and by ~ixing accompanied with mild heating, but this is not e~sential. Th~ concentrate or additive-package will typi~lly be ~ormulated to contain the additives in proper ounts to provide the desired concentration in the final formulation when the additive-package is combined with a predetermined amount of ba~e lubricant. Thus, the detergent inhibitor/antiwear agent mixturec of the presen~ invention can be added to sm~ll amounts of ~ase oil or other compatible ~olv~nts along with other desirable a~ditives to form additive-packages containing active ingredients in "
i .

13273~0 . ~ 42 -collective amount of typically from about 2.5 to about 90%, and preferably from about 15 to about 75%, and most pre~erably ~rom about 25 to about 60% by weight additives in tAe appropriate proportions with the remainder being ~ basa oil.
:.` The final formulations ~ay amploy typically about :~ 10 wt. % of the additive-package with the remainder being base oil.
~`s All of ~aid weight percent~ expre-~sed herein ~' (unless otherwis~ indicated~ are ba~ed on ac~ive ingredient ~.~ (A.I.) conten~ of the additive, and/or upon the total - weight o~ any additiv~-package, or formulation which will be the su~ of the A.I. weight of each additive plus the waight of total oil or diluent.
This invention will be further understood by reference to the following examples, wherein all parts are . part~ by weight, unle s otherwi~e noted and which include `~. preferr~d embodlment~ of the invention.

, ., , .

.

.

,~
.

`` 1327~
, -- ~, 3 E~PL~S

A series of fully formulated SAE 15W4C lubric:ating oils are prepared having the components identified in Table I.

.
. .

,~ .~t ~r ~','' ,~S
'J~
'~
!, .~

~ !

`~

t 't ` 1~273~0 ' -- 44 --.

~ o c~
,. E'l ~i U~ O
X ~ O e~ o ,`.~ Z
O ~
.~ h ~ ~ O t ,.~ ~ U~
~ ~a .:
.
~, J~ ~ a~

J'~

~ ~ O O O O
~ ~ X~ ~u~ 3 ~ 3 ~ o~ ~ ~
~ C ~ ~ ~ --I
~ h oC~ O ~ o o ~ O a~ --13273~

O ~~ 3 a ~
O ~ ~ O
Z ,~ o ~ O ~ h O 'I C ,~ C~ X--o ~ 3 ~ U
,, ~ o ~ u ~, ~ J~
U 0- ~

Z 4~ I o ~ ~ o U

2 ~ ~o 2 U U ~ o O I ~ ~ C ` 5 3 -~ U ~ 3 ~ O ~ ~
oO 3 ~ " ~ ~ ~ X .c o ~ ~ o ~ o o V U. C'~ 4 ,5 d' .~ ,~ C C ,~

~O C~. o .C

Ho C ~ C ~ 5 ~ ~ I .. C ~ ~;

h ~ ~ ~ ~ U ~ ~ ~ ~ U ~ " ~ ~ ~ C

0 ~3 o ~ ~g N J~ ) h ia 3~ U 5 f3~ ~ ~ o '2 ~ 3 0 ,C J o :

- 1~273~

The formulations are subjected to a Cummins NTC-400 field test (loads = refrigerated trailers; 80,000 lbs. gross vehicle weight), approx. 80% load factor;
continental United States service (ex-Alaska), with majority of hauling from Dallas to Pacific Northwest, wherein diesel fuels <0.3 wt% sulfur were employed.
Also included in the above tests are the following commercial SAE 15~40 lubricating oils. These formulations include ashless dispersant, overbased alkaline earth metal detergent inhibitors and zinc dihydrocarbyl dithiophosphate antiwear agents.
:, Comparative : Test Oils Wt% SASHTBN (D2896) . .
Oil C 1.0 10 Oil D 1.1 12 Oil E 0.72 6.9 Oil F 1.0 10 Oil G 1.0 8 Oil H 1.0 8 Oil I 1.0 8 Oil J 0-9 7 Oil K 1.95 14 The data thereby obtained are set forth in Table . s:
~ .~

,:~

:,j :~, . ..
, ,,, ".
F

,,.,~

1~273~0 N ~ ~ 8 8 ~ ~o ~ ~ ~ ~ o 3 o ~ ~ ~ a ~ 3 ~ ~ s O ~ O ~ ~
æ U~ O ~ 8 8 0 0 ~0 æ ~ ~ ~ O O

¦ ~ ~ 8 ~, . oo ~ ~ ~ ~ . $ . ~ . ~ o Ui ~s3 0 ~ 8 ~ o o .~ t- ¦ N ~ a; ~ '.0 0 ~r ~ O N ~ . . X 1~ O O
~ S ¦ I~ ~ a~ Ul 0 N ~ ~ ~ v O ~ $ 8 ~ a~ 1~ æ O O ~ O O

I ~ O O ~g o, o q o o o o ,~ ~ ~ ~ o u~ ~ 8 O~ o O O
O g~--U7 o ~ 8 o o o o O O

¦~ ~ o ~ O ~ In O ~ ~, 0 ~ _ . . . r N O O O oN

.' ¦~ C~l ~ ;S O ON ~ O N ~i ~ tO ~ 01 N ~ O O

.. l3~ O 5~ ~ In ~ O 1'~ 0 N U- _ ~ ~ 8 8 ~ ~ o @ o 8 o 1 0 10 N 1~ O O

13~3~

FroDI the data in Table III, it can b~ ~een that thQ oils oP Example~ 1 and 2 provide uperior crownland cleanline~s without sacrificing any of tAe remaining p~r~ormance properites.
Th~ a~hl2~8 oil8 of thi~ inv~ntion are particularly useful in heavy duty diesel engine~ employing roller ca~ ~ollower~. The ashles oil~ o~ this invention are pr2ferably employed in heavy duty di esel engine~ which 2mploy normally liquid ~u~l~ having a sulfur content of less than 1 wt~%, more preferably less than 0.5 wt.t, still more preferably less than 0.3 wt.% (e.g., fro~ about o.1 to about 0 . 3 wt. %3, and most preferably less than o . ~
(e.g., from 100 to 500 ppm sulfur). Such nor~ally liquid fuels include hydrocarbonaceous petrol~u~ distillate fuels such a~ die~el fuels or fuel oils a~ defined by ASTM
Specification D396. Compre~sion ignit2d 2nyines can also employ normally liquid fuel compositions compri~ing non-hydrocarbonaceous materials such a~ alcohols, ethers, organonitro compound~ and the like (e.g., methanol~
ethanol, diathyl ether, methyl ethyl e~her, nitromathane ) are also within t~e scope of this invention a~ are liquid ~uels derived from vegetable or mineral sources such as "
corn, alfalf;~, shale and coal. Normally liquid fuels which are mixtures of on~ or more hydrocarbonaceous uel~ and one or more non~hydrocarbonaceous materials are also cont~platedO Examples o~ such mixtures are combinations o~ die3el fu~l and ether. Particularly pref~rred is No. 2 di~s~l ~u~l.
The lubricating oils of thi~ invention are p~rticularly us~ful in the crankcase of die~el engines having cylinders (g~n~r~lly from 1 to cylinder3 or more por ~ngin~) wher~in there i~ housQd for vertical cyclic r~ciprocation therein a pi~ton provided with a ~ight top land, ~hat is, cylinder~ wh~rein the distanc~ botw*en the piston'~ top land and th2 cylinder wall liner i~ reduced to ~ini~iz~ the a~ount Or particulat~s g~nerated in the 1~2~3~
- 49 ~
cylinder's ~iring chamber (wherein the fuel i~ co~busted to gon~rat~ power). Such tight top lands can also provide i~proved fuel economy and an increase in the effective compression ratio in the cylinder. The top land comprises the region of the generally cylindrical pi~ton above the top pi8ton ring groove, and the top land, therefore, is generally characterized by a circular cross-section (taken along the longitudinal axis of the piston). The outer periphery of the top land can co~pri~e a substantially vertical ~urface which i8 de~igned to be substantially parallel to the vertical walls of the cylinder liner.
(Such top lands are herein referred to as "cylindrical top landsn.) Or, as i~ preferred, th~ top land can bs tapered inwardly toward the center of the pi~ton fro~ the point at which the top land ad;oin~ the top piston ring groove and the upp~r~ost surface of the pi~ton, i.e., the 'crown".
Th~ di~tance between ~he top land and the cylinder wall liner, herein called the "top land clearance", will ~, prefarably range from about 0.010 to 0.030 inch for cylindrical op lands . For tapered top lands, the lower top land clearance (that is, the top land clearance at the point at which the top land is adjoined to the top piston ring groove) is prQferably from about 0.005 to 0.030 inch, and more preferably from about 0.010 to 0.020 inch, and the upper top land clearance, that is, the top land clearance at th~ pi~ton crown, is preferably fro~ about 0.010 to 0.045 inch, and more preferably from about 0.015 to 0.030 inch. While the top land clearance can be le~s than the di~ensions qiven above (e.g., less than 0.005 inch), if such l~s~r dictance~ do not result in und~sired contact of thQ top land portion of th~ piston with the cylinder wall liner during operation of the engine, which is undesirable du~ to th~ r~sultan~ ~amage to ~he liner. Gen~rally, the h~i~ht of the top land (that i3, the vertical dlstance, as m~a~ured along th~ cylinder wall liner, ~rom tha bottom of th top land to th- top of tho top land) is rrO~ Dbout C.l ~327~

~ 50 =
to ~bout 1.2 inch, which is generally from about O.8 to 1.2 inch for 4-cycle d$e3el engines and fro~ about 0.1 to 0.5 inch for 2-c~cl~ diesel engine~. ~he design o~ diesel engine~ and ~uc~ pi~tons having such tight top lands is within the skil l of th~ skillad arti~an and need not be fur~her dsscribed herein.
T~e principles, preferr~d embodimants, and modes o~ operation of the present invention have been described in the foregoing speci~ication. Th~ invention which is intended to ~e protected herein, however, i8 not to be construed as limitQd to the particular Porms disclosed, ~inc~ thes~ ara to be regarding a~ illustrative rather than re~trictive. variations and changas may be made by those ~killed in the art without departing from the spirit of the invention.

~.

.
:j ~.

Claims (25)

1. An ashless heavy duty diesel lubricating oil composition which comprises a major amount of an oil of lubricating viscosity and (A) at least 3 weight percent of at least one ashless dispersant, (B) at least 2 weight percent of at least one sulfurized alkyl phenol, and (C) at least 0.1 weight percent of at least one organo-sulfur compound of the formula wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkylaryl or arylalkyl radicals having from 2 to about 30 carbon atoms, and w and z are numbers from 1 to about 8, wherein the lubricating oil is characterized by a total sulfated ash (SASH) level of less than 0.01 weight percent.

2. The composition of claim 1 wherein said ashless dispersant comprises at least one member selected from the group consisting of oil soluble salts, amides, imides, oxazolines and esters, and mixtures thereof, of long chain hydrocarbon substituted mono and dicarboxylic acids or their anhydrides wherein said long chain hydrocarbon group is a polymer of a C2 to C10 monoolefin, said polymer having a number average molecular weight of from about 700 to 5000.

3. The composition of claim 2 wherein said long chain hydrocarbyl substituted mono or dicarboxylic acid material comprises a polyolefin, substituted with an average of from about 0.8 to 2.0 moles, per mole of polyolefin, of a substituent group comprising an alpha or beta-unsaturated C4 to C10 monounsaturated dicarboxylic acid producing material.

4. The composition of claim 3 wherein said alpha or beta- unsaturated C4 to C10 monounsaturated dicarboxylic acid producing material comprises a dicarboxylic acid, or anhydride or ester thereof.

5. The composition of claim 4 wherein said substituent group comprises a member selected from the group consisting of fumaric acid, itaconic acid, maleic acid, maleic anhydride, chloromaleic acid, dimethyl fumarate and chloromaleic anhydride.

6. The composition of claim 2 wherein said long chain hydrocarbyl substituted acid material comprises a polyolefin and substitutent group selected from the group consisting of acrylic acid, methacrylic acid, crotonic acid and cinnamic acid.

7. The composition of claim 1 wherein said ashless dispersant comprises polyisobutenyl succinimide of a polyalkylene polyamine having an average of from 2 to 60 carbon atoms and from 1 to 12 nitrogen atoms per molecule of said polyamine, wherein said polyisobutylene moiety is derived from polyisobutylene having a number average molecular weight of from about 800 to 3000.

8. The composition of claim 2 wherein said SASH
level is zero.

9. The composition of claim 1 wherein said ashless dispersant comprises the product of (a) a hydrocarbyl substituted C4 to C10 monounsaturated dicarboxylic acid producing material formed by reacting an olefin polymer of C2 to C10 monoolefin having a number average molecular weight of about 700 to 5,000 and a C4 to C10 monounsaturated acid material, said acid producing material having an average of at least 0.8 dicarboxylic acid producing moieties, per molecule of said olefin polymer present in the reaction mixture used to form said first acid producing material, and (b) a nucleophilic reactant selected from the group consisting of amines, alcohols, amino-alcohols and mixtures thereof.

10. The composition of claim 9 wherein said nucleophilic reactant comprises an amine.

11. The composition of claim 10 wherein said amine comprises amines containing from 2 to 60 carbon atoms and from 1 to 12 nitrogen atoms per molecule.

12. The composition of claim 11 wherein said amine comprises a polyalkylenepolyamine wherein said alkylene groups contain 2 to 40 carbons and said polyalkylenepolyamine contains from 2 to about 9 nitrogen atoms per molecule.

13. The composition of claim 12 wherein said amine comprises polyethylenepolyamine and said reaction product is borated.

14. The composition of claim 10 wherein said amine contains from 3 to 9 nitrogen atoms per molecule, and wherein said hydrocarbyl substituted acid producing material contains succinic moieties wherein from about 0.1 to about 1.0 mole of said succinic moieties contained in said olefin polymer is reacted per equivalent of said amine.

15. The composition of claim 14 wherein said reaction product contains about 0.05 to 2.0 weight percent boron.

16. The composition of claim 15 wherein at least 2 moles of acid producing material per mole of said second nucleophilic reactant are present in said reaction mixture.

17. The composition of claim 16 wherein said ashless dispersant is borated and wherein said reaction mixture includes boric acid.

18. The composition of claim 17 wherein said olefin polymer comprises polyisobutylene.

19. The composition of claim 18 wherein said number average molecular weight of said olefin polymer is from about 1500 to 3,000, and wherein said amine comprises a polyalkyene polyamine having an average of from about 5 to 7 nitrogen atoms per molecule.

20. An additive concentrate which comprises (A) from about 10 to about 70 weight percent of at least one oil soluble ashless dispersant, (B) from about 10 to about weight percent of at least one sulfurized alkyl phenol, (C) from about 0.5 to 5 weight percent of at least one organo-sulfur compound of the formula wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkylaryl or arylalkyl radicals having from 2 to about 30 carbon atoms, and w and z are numbers from 1 to about 8, and from about 30 to 80 weight percent base oil.

21. A method for improving the performance of a heavy duty diesel lubricating oil adapted for use in a diesel engine in conjunction with a normally liquid fuel having a sulfur content of less than 1 weight percent which comprises controlling the metal content of the oil to provide a total sulfated ash (SASH) level in said oil of less than 0.01 weight percent, and providing in said oil (A) at least about 3 weight percent ashless dispersant, (B) at least about 2 weight percent sulfurized alkyl phenol oxidation inhibitor, and (C) a copper corrosion inhibiting amount of at least one organo-sulfur compound of the formula wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkaryl or aralkyl radicals having from 2 to 30 carbon atoms, and w and z are numbers from 1 to about 8.

22. A method for improving the performance of a heavy duty diesel lubricating oil adapted for use in a diesel engine provided with at least one tight top land piston which comprises controlling the metal content of the oil to provide a total sulfated ash (SASH) level in said oil of less than 0.01 weight percent, and providing in said oil (A) at least about 3 weight percent ashless dispersant, (B) at least about 2 weight percent sulfurized alkyl phenol oxidation inhibitor, and (C) a copper corrosion inhibiting amount of at least one organo-sulfur compound of the formula wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkaryl or aralkyl radicals having from 2 to 30 carbon atoms, and w and z are numbers from 1 to about 8.

23. The method according to claim 22 wherein said diesel engine is adapted for use in conjunction with a normally liquid fuel having a sulfur content of less than 1 weight percent.

24. In a diesel engine provided with a lubricating oil crankcase and at least one tight top land piston, the improvement which comprises providing in said crankcase a lubricating effective amount of an ashless lubricating oil composition which comprises a major amount of an oil of lubricating viscosity and (A) at least about 3 weight percent ashless dispersant, (B) at least about 2 weight percent sulfurized alkyl phenol oxidation inhibitor, and (C) a copper corrosion inhibiting amount of at least one organo-sulfur compound of the formula wherein R4 and R5 are straight or branched chain alkyl, cyclic, alicyclic, aryl, alkaryl or aralkyl radicals having from 2 to 30 carbon atoms, and w and z are numbers from 1 to about 8, wherein said lubricating oil is characterized by a total sulfated ash (SASH) level of less than 0.01 weight percent .

25. The method according to claim 24 wherein said diesel engine is adapted for use in conjunction with a normally liquid fuel having a sulfur content of less than 1 weight percent.