CA1208196A - Lubricating composition - Google Patents

Abstract

ABSTRACT

A lubricating composition is provided containing: a high viscosity synthetic hydrocarbon such as a high viscosity polyalphaolefin, a liquid hydrogenated polyisoprene or an ethylene-alphaolefin copolymer having a viscosity of 40-1000 centistopes at 100°C; a low viscosity synthetic hydrocarbon and/or optionally a low viscosity ester; and optionally an additive package to impart desirable performance properties to the composition.

Description

~8:~g~

LVBRICATING COMPOSITION

This invention relates to compnsitions useful as lubricating t)ils having high viscosity index, irnproved resistance to oxidative deg-radation and r~sistance to viscosity losses caused by permanent or ~emporary shear.
Acc~rding to the instan~ invention a lubricating composition is provided comprising (1~ a high viscosity synthetic hydrocarbon such as high viscosity polyalphaolefins, liquid hydrogenated poly-isoprenes or ethylene-alphaolefin oligomers; (2) a low viscosity synthetic hydrocarbon, such as alkylated benzene or low viscosity polyalphaolefin; and/or, optionally, (3) a low viscosity ester, such as monoestsrs, diesters, polyesters and optionally (~L) an additive package.
A further object of the invention is to provide lubrica$ing compositions exhibiting permanent shear stability, superi~r oxidative stability and excellen~ temperature-viscosity properties.
A further object of the invention is to provide a lubricating composition with properties not obtainable with conventional poly-meric thickeners.
The viscosity-temperature rela~ionship of a lubricatiny oil is one o~ the critical criteria which must be considered when selecting a lubricant for a particular applica~ion. The mineral oils commonly used as a base for single and multi~raded lubricants exhibit a relatively lar~e change in viscosity with a change in temperature.
Fluids exhibiting such a relatively large chan~e in;viscosi~y with temperature are said to have a low viscosity index. The visc9sity index of a commun paraffinic mineral oil is usually given a value of about 100. Viscosity index (Vl) is determined according to ASTM
Method D 2770-74 wherein the VI is rela~ed ~o kinematic viscosities measured at 40C and 100C.
Lubricating oils composed mainly of mineral oil are said to be single graded. SAE gradi~g requires that oils have a certain minimum viscosity at high temperatures and, to be multigraded; a certain maximum viscosity a~ low temperatures. For instance, an oil having a viscosity of 10 cSt. at 100C (hereinafter all viscosities ~t . . .

~2~8~
are at 100C unless otherwise noted) wDuld be an SAE 30 and if that oil had a viscosity o:E 3400 cP. at -20C, the oil would be graded 10W-30. An unmodified mineral oil of 10 cSt. can not meet the low temperature requirements for a 10W-30 multigrade rating, 5 since its viscosity index dictates that it would have a viscosity considerably gre~ter than 3500 cP. at 20C, which is th~ maximum allowed viscosity for a 10W ra~fing.
The viscosity requirements for qualification as multigrade engine oils are described by the SAE Engine Oil Viscosily Classifi-10 cation- SAE J300 :sEP80, which became effective April 1, 1982.
The low ~emperature (W) viscosity requiremPnts are determined by ASTM D 2602, Method of Test ~or Apparent Viscosity of ~lotor Oils at Low Temperature Using the Cold Cranking Simulator, and the results are repor~ed in centipoise (cP). The higher temperature 15 (100~C~ viscosity is measured according to ASTM D445, Method ol Test for Kinematic Viscosity of Transparent and Opaque Liquids, and the results are reported in centistoke~ (cSt.). The following ta?Dle outlines the high and low temperature requirements f~r the recogni2ed SAE grades for engine oils.

20 SAE Vi~cosity (cP) at Vi~cosi~y (cSt.) Viscosity ~emperature (C) at 100C
Grade Max. Min. Max.
OW 3250 at -30 3.8 SW 3500 at -25 3.8 25 lOW 3500 a~ -20 4.1 15W 3500 at -15 5.6 20W 4500 at -10 5.6 25W 6000 at -5 9.3 5.6Less than 9.3 30 30 9.3~ess than 12.5 12.5Le~s than 16.3 16.3Le~s tban 21.9 ln a similar manner, SAE J306c describes the viscometric qualifications ~or axle anà manual ~ransmission lubricants. High 35 temperature (100C) ViscDsity measurements are performed according tO AST~q D445. The IDW temperature viscosity values are deter-~s:a~36 mined accordin~ to ASTM D2983, Method of Test for ApparentViscosity at Low Temperature Using the Brookfield Viscometer and these results are reported in centipoise (cP), where (cP) and ~cSt) are related as fDllow~:

cs~ = cP
Density, ~7~m3 The following table summarizes the high and low temperature requiremen~s for qualification of axle and manual transmission lub-ricants .

SAEMaximum Temper~ture Viscosity at Viscosityfor Viscosity lOO~C, cSt.
Grade of 150 000 cP c Minimum Maximum 70W -55 ~~
75~' -40 4.1 ~5 80W -26 7.0 ~5W -~2 11.0 -- 13.5 24.0 140 -- 24.0 41.0 It is obvious from these tables that the viscosity index of a broadly mu]tigraded oil such as 5W-40 or 70W-140 will require fluids having considerably higher viscosity index than narrowly multi-graded lubricants such as 10W-30. The viscosity index require-ments for different multigraded fluids can be approximated by the use of ASTM Standard Viscosity-Tempearture Charts for Liquid Petroleum Products (D 341).
~f one assumes that extrapola~ion of the high temperature (40C and 100C) viscosi~ies to -40C or below is linear on chart D 341, then a line connec~ing a 100CC viscosi~y of, ~or example, 12.5 cSt. and a low temperature viscosity ol 3500 cP at -25C would give the correct 40C viscosity and permit an approximation of the minimum viscosity index required for that particular grade of oil (lOW-40) .
' ;

~2~g6 The 40~C viscosity estimated by linearly connecting the 100C
and -25C viscosities would be about 70 c~t- The viscosity index of an oil having R.V.loo= 12.5 oSt. and K.V.40= 70 cSt. would ~e a~out 180 (ASTM D 2270-74). Unless the -25~C viscosity of a 5 fluid is lower than ~he linear relationship illustrated, then an oi]
must have 3 viscosi~y index of at least 180 to even potentially qualify as a 10W-40 oil.
In actual ~act, many V . I . improved oils have viscosities at -25C which are considerably ~reater than predicted by linear 10 extrapolation of the K.V.loo and K.V.40 values. Therefore, even having a V . l . o~ 180 does not guarantee the blend wou]d ~e a -40 oil.
Using this technique minimum viscosity index requirements for various grades of crankcase or gear oils can be estimated. A fe~
15 typica] estimations are shown in the following table:

Estimated Required Crankcase K-V-100C K~V~40oc Viscosity Oil Grade cSt. cSt. _ Index 10~`-30 9.3 60 135 20 SW-40 12.5 70 180 OW-50 16.3 75.5 232 Gear Oil Grade 80W-140 24 27~ 1~2 2575W-140 24 200 l49 lt can thus be seen that preparation of very broadly graded lubricants, such as 5W-40 or 75W-250 requires thickeners ~hich 30 produce very high viscosity indices in the final blends.
It has been the practice to irnprove the viscosity index of mineral oils or low viscosity synthetic oils by adding a polymeric ~hickener to relatively non-viscous base fluids. Polymeric thick-:~2~
eners are conunonly used in the production of multigrade lubricants.
Typical polymers used as thickeners include hydro~enated styrene-isoprene block copolymers, rubbers based on ethylene and propyl-ene (OCP), polymers produced by polymerizing high molecu]ar weight esters of the acrylate series, polyisobutylene and the like.
These polymeric thickeners are added to bring the viscosity o~ a base fluid up to that required for a certain SAE grade and to increase the viscosity index of the fluid, allowin~ the production of multigraded oils. Polymeric VI improvers are traditionally high molecular weight rubbers whose molecular weights may vary from 10,000 to 1,000,000. Since the thickening power and Vl increase are related to the molecular weight of the VI improver, most of these polyn~ers normally have a molecular weigh~ of at least 100,000.
The use of these hi~h molecular wei~ht Vl improvers, in the production of multigraded lubrican~s has some serious drawbacks:
1. They are very sensitive to oxidation, which results in a loss of VI and thickening power and frequently in the formation of unwanted deposits.

2. They are sensitive to large viscosity losses from mechanical shear when exposed to the high shear rates and stresses encountered in crankcases or gears.

3. They are susceptible to a high degree of ~emporary shear .
Temporary shear is the result of the non-Newtonian viscometrics associatèd with solu~ions of high molecular weight polymers. It is caused by an alignment of ~he polymer chains with the shear field under high shear rates with a resultant decrease in viscosity. The decreased viscosity reduces the wear protection associated ~ ith viscous oils. Newtonian fluids maintain their viscosity regardless of shear rate.
We have found that certain combinations of ~]uids and additives can be used to prepare multigraded lubricants which outperform prior art formulations and have none or a greatly decreased amount of the above listed deficiencies found in polymerically thickened ~5 oils.
Certain specific blends of high viscosity synthetic hydrocar-bons, low viscosity synthetic hydrocarbons and optionally low :-.

~2~96 viscosity esters form base fluids from which superior crankcase or gear oil~ can be produced by the ~ddition of the proper additive t'packages". The finished oils thus prepared exhibit very high stability to permanent shear and, because of their Newtonian nature, 5 very little, if any, temporary shear and 50 maintain the viscosity required for proper wear protection. The oils ~f this invention hav~ remarkably better stability toward oxidative degradation than those of the prior art. The unexpectedly high viscosity indices produced from our base fluid blends permit the preparation of lO broadly multigraded crankcase fluids, such as 5W-90 and gear oils such as 75W-140. Up tD now it has been difficult if not impossible, to prepare such lubricants without the use of frequently harm~ul amounts of polymeric Vl improvers. ln the instant invention, the high viscosity synthetic hydrocarbons having viscosities of 40 to 15 1000 cSt. may be polyalphaolefins, ethylene-alphaolefin oligomers or hydrogenated polyisoprene oligomers.
The high viscosity polyalphaolefins of the present invention, have viscosities of from 40 to 1000 cSt., preferably from 40 to 250 cSt., and are convenient]y prepared by any of a series of methods 20 described in the literature. The catalysts employed are those commonly referred to as Friedel-Crafts catalysts. Such catalysts cause cationic oli~omerization of alphaolefins, such as octene-1 or decene-1 to molecular weights ranging up to several thousand, depending on the catalyst and polymerization conditions employed.
25 While a variety of Friedel-Crafts catalysts can be used to prepare alphaolefin oligomers, it is common to use catalysts based on alu-minum halides for the production of the moderately high molecular weight oils useful in ~he present invention. Descriptions of such catalysts can be found in United States Patent No . 3, 637, 503 to 30 Gulf Research and DevelDpment Company, Uni~ed States Patent No.

4,041,098 t~ Uniroyal, Inc. and United States Patent No. 3,312,748 $o Esso Research and Engineering Co.
Ziegler catalysts, such as described in United States Patent No. 3,179,711 to Sun Oil Company can also be used to prepare 35 oligomers in the molecular weight range useful in this invention.
Polyalphaolefins can likewise be prepared with peroxide cata-lysts, BF3 based catalysts anà by thermal polymeriza~ion. These methods, however, generally produce only low molecular weight oligomers.
The hi~h molecular weight polyalphaolefins of this invention are preferably hydro~enated to decrease their level of unsaturation and thereby to increase their stability toward oxidation.
The alphaolefins utilized to make the high viscosity oligomers of the invention can range from C3 (propylene) ~o C14 (tetra-decene) or any mixtures, although oligomers of octene-1, decene-1 and dodecene-1 are pre~erred because of their high viscosity indices and low pour points.
The high viscosity ethylene-alphaolefin oligomers of ~his inven-tion are conveniently prepared by Zie~ler catalysis. Many refer-ences exist covering methods of producing liquid oligomers of ethy-lene and alphaolefins (particularly propylene). Polymerization is typically performed by subjecting the monomer mixture usua]ly in a solvent to the combination of an organo aluminum compound and a vanadium or titanium compound. The products formed can range from materials having viscosities as low as 20 cSt. to rubbery semi-soiids depending on the choice of catalyst, the addition of ~0 molecular weight regulating species, temperature of polymerization and, especially, ~mposed hydrogen pressure. In some instances lo~
viscosity oligomers are prepared by the pyrolysis of high viscosity oligomers or rubbery solids. Typical preparations of liquid ethylene-alphaolefin copolymers can be found in references, such as:
United States Patent No. 3,634,249 to Esso Research and Engineering Co.; United States Patent No. 3,923,919 tD Sun Ventures, Inc.; United States Patent No. 3,851,011 $o Sun Research and Development Co.; United States Patent No.
3,737,477 to Sun Oil Company; United States Patent No.
3,499,741 to Texaco, Inc.; United States Pa~ent No. 3,681,302 to Texaco, Inc.; United States Patent No. 3,819,592 to Vni-royal, Inc.; United States Patent No. 3,896,094 to Uniroyal, Inc.; United States Patent No. 3,676,521 to Uniroyal, Inc.;
Belgian Patent No. 570,843; United States Patent No. 3,068,306, and United States Patent No. 3,328,366.
While oligomers of ethylene and at least one other alphaolefin o~ this invention may be hydrogenated to increase their stability :~2~96 toward ~xidation, the proper choice of polymerization cata]ysts in the presence of hydrogen often produces oligomers having very low levels of unsaturation directly. The alphaolefins which can be used singly or in combinations with ethylene include linear alphaolefins of

5 C3 (propylene) to C19 (tetradecene) and branches alphaole~ins of the same mo]ecular wéight ranye, provided that the branch point is at least in the beta position to the dou~e bond (e . g . 4-methy]
pentene-1). lnasmuch as the rate of polymeri2ation of such olefins relative to ethylene decreases with monomer size, propylene and the 10 lower molecular weight olefins are the preferred monomers in the preparation of the oligomers o~ ethylene and at least one other alphaolefin of this invention.
The viscosity of the ethylene-alphaolefin oligomers of this invention is preferably 90 to 100û cSt. while the etllylene content is 15 preferably 30 to 70 wt.%.
It is also possible to use in this invention oligomeric ethylene-alpha olefin polymers which contain controlled amounts o~ unsatura-tion introduced by copolymerization with certain non-conjugated diene such as dicyclopentadiene, ethylidene norbornene and 1,4-20 hexadiene. The introduction of unsaturation is sometimes desired ifthe oligomer is to be treated in any way to produce polar function-ality thus giving the oligomer dispersant properties.
The oligomeric polyisoprenes of this invention may be prepared by Zieg]er or, preferably, anionic polymerization. Such polymeri-25 zation techniques are described in United States Patent 4,060,492.
For ~he purposes of this invention, $he preferred method ofpreparation for the liquid hydrogenated polyisoprenes is by the anionic alkyl lithium catalyzed polymerization of isoprene. Many re~erences are available to thsse familiar with this art which 30 describe the use of such catalysts and procedures. The use o~
alkyl lithium catalysts such as secondary butyl lithium results in a polyisoprene oligomer having a very high (usually greater than 80~) 1,4-content, which results in backbone unsaturation.
When alkyl lithium catalysts are modified by ~he addition of 35 ethers or amines, a controlled amount of 1,2- and 3,4- addition can take place in the polymeri~ation.

:~1.2~83L~6 , , 3 2 H CH2 RLi ~ -~CH2-C-CH-CH
1,4-~ddition RLi ~ CH3 ROR
~CH2-C~ ~ ~CH2-(:H}
CH C-CN
.. " 3 CH2 C~2 1,2-addition 3,4-addition Hydrogenation of these structures gives rise to the saturated species represented below:

. 3 CH3 -CN2-C=CN-CH2-- H2 ~ -CH2-C-CH2-CH~

1,4-addition A

CH3 ~H3 -~H2-C- - H ~ CN2 C

"
~H2 CH3 1 ,2-addition B

-CH ~CH- ~ -CH -CH-2 ' H2 2, .. 3 H-C-CH3 CN2 ~H3 3,4-addition C

-10- ~1L2~ L96 Structure A is the preferred structure because of its low Tg and because i~ has a lower percent of its mass in the pendant groups (CH3-). Structure B is deficient in that the tetrasubsti-tuted carbons produced serve as points of thermal instability.
5 Structure C has 60~o of its mass in a pendant (isopropyl) group which, if repeated decreases the thickening power of the oligomer for a given molecular weight and also raises the Tg of the resultant polymer. This latter property has been shown to correlate with viscosity index. Optimization of structure A is desired ~or the best 10 combination of thickening power, stability and V . l . improvement properties.
Another feature of alkyl lithium polymers is the ease with which molecular weight and molecular weight distribution can be controlled. The molecular weight is a dire~t function ol the mono-15 mer to catalyst ratio and/ takin~ the proper precautions to exeludPimpurities, can be controlled very accurately thus assuring good quality control in the production o~ such polymer. ~he alkyl lith-ium catalysts produce very narrow molecular weight distributions such that Mw/Mn ra~ios oî 1.1 are easily gained . ~or V . ~ .
20 improvers a narrow molecular weigh2 dis~ribution is highly desirab~e since, at the given molecular weigh~, thickening power is maximized while oxidative and shear instability are minimized. If desired, broad or even polymodal M.W. distributions are easily produced by a variety of techniques well known in the art. Star-shaped or 25 branched polymers can also ~e readily prepared by the inclusion of multi~unctional monomers such as divinyl benzene or by termination of the "living" chains with a polyfunctiona3 coupling a~ent such as dimethylterephthalate .
It is well known that highly unsaturated polymers are consid-30 erably less stable ~han saturated polymers toward oxidation. It isimportant, therefore, that the amount o~ unsaturation present in the polyisoprenes be drastically reduced. This is accomplished easily by anyone skilled in the art using, for instance, a Pt, Pd or Ni catalyst in a pressurized hydrogen atmosphere at elevated temper-35 ature.
Regardless o~ the mode o~ preparation, isoprene oligomers ,. .
....
.. . ... ., . . . . .. , . .... ~ . . . .. . . . . . . .

8:1L9~
require hydrogenation to reduce the high level of unsaturation present after polymerization. For optimum oxidation stability, 9~%, and preferably 99% or more of ~he olefinic linka~es should be saturated.
To insure good oxidative and shear stability the high viscosity synthetic hydrocarbons of ~is invention shou~d have viscosities ranging from about 40 cSt. to about 1000 cSt.
The low viscosity synthetic hydrocarbons of ~he present invention, having viscosities of from 1 to 10 cSt., consist primarily of oligomers of alphaolefins and alkylated benzenes.
Low molecular weight oligomers of a3phaolefins from C8 ~octene) to C12 (dodecene) or mixtures of ~he olefins can be utilized. Lo~-viscosity alphaolefin oli~omers can be produced by Ziegler catalysis, thermal polymeriza~ion, free radically catalyzed polymerization and, preferably, BF3 catalyzed polymerization. A host of similar pro-cesses involving BF3 in sonjunction with a cocatalyst is kno- n in the patent literature. A typical polymerization technique is des-cribed in United States Patent No. 4,045,~08.
The alkyl benzenes may be used in the present invention a]one or in conjunction with low viscosity polyalphaolefins in blends with high viscosity synthetic hydrocarbons and low viscosity esters.
The alkyl ben2enes, prepared by ~riedel-Crafts alkylation of ben-~ene with olefins are usually predominantly dialkyl benzenes wherein the alkyl chain may be 6 to 14 carbon atoms lon~. The alkylating olefins used in the preparation of alkyl benzenes can be straight or branched chain olefins or combinations. These materials may be prepared as shown in U.S.P. 3,909,432.
The low viscosity esters OI ~his invention, having viscosities of from 1 to 10 cS~. can be selected from classes of esters readily available commercially, e. 9 ., monoesters prepared from monobasic acids such as pelargonic acid and alcohols; diesters prepared from dibasic acids and alcohols or from diols and monobasic acids or mixtures of acids; and polyol esters prepared from diols, triols (especially trimethylol propane), tetraols (such ~s pentaerythritol), hexaols (such as dipentaerythritol~ and the like reacted with mono-basic acids or mixtures of acids.

~Z~ 96 Examples of such esters include tridecyl pelarg~nate, di-2 ethylhexyl adipate, di-2 etllylhe~:ylaz~late, trimethylol propane triheptanoate and pentaerythritol tetraheptanoate.
An alternative ~o the synthetically produced e~ters described 5 above are those esters and mixtures of esters derived from natural sources, plant or animal. Examples of these materials are ~he fluids produced from jojoba nuts, tallows, ~afflowers and sperm whales.
The esters used in our blends must be carefully selected to insure compatibility of all components in finished lubricants of this 10 invention. If esters having a high degree of polarity (roughly indicated by oxygen content~ are blended with certain combinati~ns of high viscosity synthetic hydrocarbons and low viscosity synthetic hydrocarbons, phase separation can occur at low temperatures with a resultant incr2ase in apparent viscosity. Such phase separation 15 is, of course, incompatible with lon~ term storage of lubricants under a variety o~ temperature conditions.
The additive "packages" mixed with the rec~runended base oil blend for the production o~ multigraded crankcase fluids or gear oils are usually combination of various types of chemical addi2ives 20 so chosen to operate best under ~he use conditions which the par-ticular formu~ated fluid may encounter.
Additives can be classified as materials which either impart or enhance a desirable property of the base lubricant blend into which they are incorporated. While the general nature of the additives 25 might be the same for various types or blends o~ the base lubri-cants, ~he specific additives chosen will depend Dn the particular type of service in which the lubrican is employed and the charac-teristics of the base lubricants.
The main types of current day additives are:
1. Dispersants, 2. Oxidation and Corrosion Inhibitors, 3. Anti-Wear Agents, 4. Viscosity Improvers, 5. Pour Point Depressants,

6. Anti-Rust Compounds, and

7. Foam Inhibitors.

-13~ 83~9~

Normally a finished lubricant will contain several and possibly most or all of $he above types of additives in what is cornmonly called an fladditive package. " The development of a balanced additive pac}cage involves considerably more work than the casual 5 use of each of the additive types. Quite o~ten functional di~ficu~ties arising from combinations o~ these materials show up under actual operating condi~ions. On the other hand, certain unpredictable synergistic ef~ects of a desirable nature may also become evident.
The only methods curren~ly available îor ob~aining such data are 10 from extensive full scale testing both in the laboratory and in the fie]d. Such testing is costly and ~ime-consuming.
Dispersants have been àescribed in the literature as "deter-gents". Since their function appears to be one of effecting a dispersion of particulate matter, rather than one of "cleaning up"
15 any existing dirt and àebris, it is more appropriate to categorize them as dispersants. Materials of this type are generally molecules having a large hydrocarbon "tail" and a polar group head. The tail section, an oleophilic group, serves as a solubilizer in the base fluid while the polar group serves as the element which is attracted 20 to particulate contaminants in the lubricant.
The dispersants include metallic and ashless types. The metallic dispersants include sulfonates (products of the neutraliza-tion of a sulfonic acid with a metallic base), thiophosphonates (acidic components derived from the reaction between polybutene 25 and phosphous pentasulfide) and phenates and phenol sul~ide salts (the broad class of metal phenates includes the salts of alkylphen-ols, alkylphenol sulfides, and alkyl phenol aldehyde products).
The ashless type dispersants may be categ~rized into two broad types: high molecular weight polymeric dispersants for the formula-30 tion of multigrade oils and 30wer mo]ecular weight additives for usewhere viscosity improvement is not necessary. The compounds useful ~or this purpose are again characterized by a "polar" group attached to a relatively high molecular weight hyàrocarbon chain.
The "polar" group generally contains one or more of the elements--35 ni~rogen, oxygen, and phosphorus. The solubilizing chains aregenerally higher in molecular weight than those employed in the metallic types, however, in some instances they may be quite ~L2~8~6 \

similar. Some examples are N-substituted long chain alkenyl suc-cinimides, high molecular weight esters, such as produc~s formed by the esteri~ication of mono or polyhydric alipha~ic alcohols with olefin substituted succinic acid, and Mannich bases fr~m high mo]ecular 5 weight alkylated phenols.
The high molecular weight polymeric ashless dispersants have ~he general formula:

R P~ R R R
C-cH2-c-cH2 C-~2-C-C~2-C 't H2 O o P O O

where O = O1eophilic Group P = Pol ar Group R = Hydrogen or Alkyl arOup The function of an oxidation inhibitor is the prevention of a deterioration associated ~ith oxygen a~tack on the lubricant base fluid. These inhibitor~ function either to des~roy free radicals (chain breakin0) or to interact with peroxides which are involved in 20 the oxidation mechanism. Amon~ the widely used anti-oxidants are ~e phenolic types (chain-breaking) e.g., 2,6-di-tert.-butyl para cresol and 4,4' methylenebis(2,6 di-tert.butylphenol), and the zinc dithiophosphates (peroxide-destroying).
Wear is ~oss of metal with subsequent change in clearance 25 between surfaces moving relative to each other. If con~inued, it will result in engine or gear malfunction. Among the principal factors causing wear are metal-to-metal contact, presence of abra-sive particulate mat~er, and attack of corrosive acids.
Metal-to-metal contact can be prevented by the addition ol 30 film-form~ng compounds which protect the surface ei~her by physical absorption or by chemical reaction~ The zinc dithiophosphates are widely used for lthis purpsse. These compounds were described under anti-oxidant and anti-bearing corrosion additives. Other e~fective additives contain phosphorus, sulfur or combinations of 35 these elements.

J.

, . . . . .. . . . . . .

3~2(~
Abrasive wear can be prevented by effective remova~ of par-ticulate ma$ter by filtration while corrosive wear from acid)c mater-i~ls can be controlled by the use of alkaline additives such as basic phenates and sulfonates.
Although conventional viscosity improvers are ~f~Pn used in "additive packa~es" their use should not be necessary for the practice o~ this invention since our particular blends of high and low molecular weight base lubricants produce the same effect.
However, we do not want to exclude the possibility of adding some amounts of conventional viscosity improvers. These materials are usually oil-soluble organic polymers with molecular weights ranging from approximately 10,000 to 1,000,000. The polymer molecule in solution is swollen by the lubricant. The volume o~ this swollen entity determines the degree ~o which the po3ymer increases its viscosity.
The func~ion of an oxidation inhibitor is the prevention of a deterioration associated with oxygen attack on the lubricant base ~luid. These inhibitors func$ion either ~o destroy free radicals (chain breaking) or to interac~ wi~h peroxicles which are invo1ved in ~he oxidation mechanism. Among the widely used anti-oxidants are the phenolic types (chain-breaking), e.g., 2,6-di-tert.-butyl para cresol and 4,4'-methylenebis~2,6-di-tert.-butylphenol), and the zinc dithiophosphates (peroxide-destroying).
Wear is loss o~ metal with ~ubsequent change in clearance between surfaces moving relative to each other. If continued, it will result in engine or gear malfunction. Among the principal ~actors causing wear are metal-to~metal contact, presence of abra-s;ve particulate matter, and attack OI corrosive acids.
Metal-to-metal conl~act can be prevented by the addition o~
film-forming compounds which protect the surface either by physical absorption or by chemical reaction. The zinc dithiophosphates are widely used for ~his purpose. These compounds were described under anti-oxidant and anti-bearing corrosion ~dditives. Other effec~ive additives contain phosphorous, sulfur or combinations of these elements.

:~2~)8~6 Pour poin~ depressants prevent the congelation of the oil at low temperatures. This phenomenon is associated with the crystal-lizati~n of waxes fr~m thP lubricants. Chemical structures ~f rep-resentative colTunercial pour point depressants are:

. paraffin ~0~ paraffin ~ ~paraffin~n - CH2-C - paraffin ~ paraffin Alkylated Wax Naphthelene Polymethacrylates Alkylated Wax Ph~no~
Chemicals employed as rust inhibitors include sulfonates, alkenyl succinic acids, substituted imidazolines, amines, and amine phosphates .
The anti-foam agents include the silicones and miscellaneous organic copolymers.
Additive packages known ~o perform adequately for ~heir recommended purpose are prepared and supplied by several major manufacturers. The percentage and type of additive to be used in each application is recomrnended by the ~uppliers. Typically avail-able packages are:
I. HITEC ~-320, ~uppl~ed by Edwin Cooper C~rp. ~or use in automotive Dear oils, * Trade Mark 9~
2. Lubrizol 5002 supplied by ~he Lubrizo3 Corp. for use in Industrial gear Qils~
3. Lubrizol 4856 supplied by the Lubri~ol Corp. for use in ~asoline crankcase oil, and 4. OLOA 8717 ~upplied by Oronite Division of Chevron ~or use in diesel crankcase oils.
A ~ypical additive package for an automotive gear iubricant would normally contain antioxidant, corrosion inhibitor, anti-wear a~ents, anti-rust a3ents, extreme pressure agen~ and foam inhi-10 bitor.
A typical additive packa~e for a crankcase 3ubricant wouldnormally be comprised of a dispersant, antioxidant, corrosi~n inhibitor, anti-wear agent, anti-rust agent and foam inhibitor.
An additive packa~e useful for formu3ating a compressor fluid 15 would typically contain an anti-oxidant, anti-wear ag~nt, an anti-rust agent and ~am inhibitor.
This invention describes blends of high viscosity synthetic hydrocarbons, havin~ a viscosity range of 40 to 1000 cSt. with one or more synthetic hydrocarbon fluids having viscosities in the range 20 of 1 to 10 cSt. and/or one or more compatible ester fluids having a viscosity range o~ 1 to 10 cSt. Such blends, when treated with a properly chosen additive "package" can be formulated in multi-graded crankcase or gear oils having superior shear stability, ~uperior oxidative stability, and Newtonian visrometric properties.
25 The blends of this invention also find uses in certain applications where no additive need be employed.
~ n discussing the constitution of the base oil blend, it is convenient ~o normalize the percentayes of hi~h viscosity synthetic hydrocarbons, low viscosity synthetic hydrocarbDns, and lo-~ vis-30 cosity esters in the final ~ubricant ~o that they total 100%. Theactual percentages used in the final formulation wou]d then be decreased depending on the amDunt of additive packages utilized.
~ ach of the in~redients, hi~h viscosity synthetic hydrocar-bons, low viscosity synthetic hydrocarbons, and low viscosity 3~ esters are an important par~ of ~his invention. The high ViscGsity synthetic hydrocarbon provides thickeniny and Vl improvement to the base oil blend. ln addition, we have discovered tha~ b]ends of ';-* Trade Mark -18~ L9~;

high vi~cosity synthetic hydrocarbons with low viscosity synthetic hydrocarbons produce fluids having much greater oxidative stability than low viscosity synthetic hydrocarbons alone. This ig i~ustrated in Example 7. The Vl improvement produced by high viscosity 5 synthetic hydrocarbon in blends with low viscosity synthetic hydr~-carbons or low viscosity esters is shown in Examples 8 and 9.
These improvements persist in blends of high viscosity synthetic hydrocarbons, low viscosity synthetic hydrocarbons, and low vis-cosity es~ers.
The low viscosity synthetic hydrocarbon fluid is frequent]y the main ingredient in the base oil blend, particularly in finished lubri-cants having an SAE viscosity grade of 30 or 40. While certain lo~
viscosity esters are insoluble in high viscosity synthetic hydrocar-~ons, the presence of low viscosity syn~hetic hydrocarbon, being a 15 better solvent for low viscosity esters, permits greater variations in the type of esters used in base oil blends of high viscosity syn-thetic hydrocarbons, low viscosity synthetic hydrocarbons, and ]o--viscosity esters.
Crankcase and gear oils consisting solely of hydrogenated 20 polyisoprene oligomers and low viscosity synthetic hydrocarbons with the proper additives produce synthetic ~luids having excellent oxidative and hydrolytic stability. Such fluids are exemplified in Examples 22 and 23.
The third optional component, low viscosity es~ers can be used 25 in combination with hydrogenated polyisoprene oligomers and low viscosity hydrocarbons or alone with hydrogenated polyisoprene oligomers. In the three c~mponent blend the proper choice of es~er and hydrogenated polyisoprene oligomers can produce crankcase and gear oil formulations having outstanding viscosity indices and lo~
30 ~emperature properties. Such ~hree component blends are illus-trated in Examples 24 and 25.
Two component blends of hydro~enated polyisoprene oligomers and es~ers can be used to prepare multigraded ~ubricants having outstanding viscometric properties, detergency, and oxidative 35 s~abili~y. While some applications present environments having high moisture ~evels, which would be deleterious to certain esters, there are other applications ~uch as automotive gear oils where the high 819~;
ester contents ~ound in the hydrogena~ed polyisoprene oligomers-ester blends can be used to advanta~e. Examples 26 and 27 illus-trate the formulation of n~ul~igrade lubricants wi~ ~uch two com-ponent blends.
When it is deemed advan~ag~ous to use a 1OW viscosity ester as part of the blend, the low viscosity hydrocarbons act as a common solvent for the ethylene-a3pha-olefin oligomers and the added ester.
Dependin~ on the polari~y of the ester, ~he latter ~wo are fre-quently somewhat incompatible. Excellent multi~raded lubricants lO can be formulated with or withou2 ester.
The third componellt, low viscosity esters, can be added to produce the superior ]ubricants of this inven~ion. High viscosity synthetic hydrocarbons and low viscosi~y ~ynthetic hydrocarbons can be used alone to produce multigraded lubricants. The addition 15 of low levels of low viscosity es~ers, usually 1-25% results in a base oil blend superior to blends of high viscosity synthetic hydrocar-bons and low viscosity synthetic hydrocarbons alone in low tem-perature fluidity.
While low viscosity esters usually constitute 10-25% of the 20 synthetic base oil blend, more or less can be used in specific formulations. When the final application involves exposure to mois-ture elimination or limitation of the am~unt of ester in blends may be advanta~eous.
The components of the ~inished lubricants OI this invention can 25 be admixed in any convenient manner or sequence.
An important aspect of the present inven~ion is in the use of the properly constituted base oil blend in combination with the proper ~ompatible additive package tn produce finished multigrade lubricants having:
l. Permanent and temporary shear stability.
2. Excellent oxidation stability.
3. High viscosity index resulting in multigraded, non-"polymeric" lubricants.
The range of percenta~es ~r each of the components, i.e., 35 high viscosity synthetic hydrocarbons, low viscosity ~ynthetic hydrocarbons, low viscosity esters, and additive packayes, will vary widely depending ~n the end use for the ~ormulated lubricant, but the ~enefits of the sompositions of this inver,tion accrue when:

,r, ~, _ . .. . . .. ~ .. . . _ IL2~ L96 The base oil blend of high viscosity ~ynthet;c hydroearbons, ]ow viscosi~y ~ynthetic hydrocarbons, andJor low viscosity ester~ con-tains (n~rmalized):
From 1 to 9996 high ~iscosity synthetic hydrocarbons, ~rom 0 to 99% low YisCoSity synthetic hydrocarbons, a-~d from 0 to 99% low viscosity esters. It is preferred to blend from 10 to 80~6 high viscosity hydrocarbons with correspondingly 90 to 20%
of at least one low viscosity ester base fluid or hydrocarbon base fluid. The fourth in~redien~, the additive package, can be used in from û to 25% of the total formulation.
The lubricants of this inven~ion, when properly Iormulated, display viscometrics of Newtonian flllids. That is, their viscosities are unchanged over a wide range of shear rates. While some of the high viscosity synthetic hydrocarbons of the invention may, in themselves, display non-Newtonian characteristics, particularly at low temperatures, the final lubricant products utilizing low viscosity oils as diluen~s are Newtonian. We have ~bserved that synthetic hydrocarbons of up to 300 cSt. are Newtonian at room temperature as shown by the absence of a Weissenberg e~fect. And while fluids of 500 to 1000 cSt. do show a Weissenberg effect, soluti~ns of such oligomers in quantities commonly used to attain Standard SAE vis-cosity grades do not.
The non-Newtonian character of currently used Vl improvers is well documented. An excellent discussion can be found in an SAE
publication entitled, "The Relationship Between En~ine Oil Viscosity and Engine Performance--Part lII." The papers in this publication were presented at a 1978 SA~ Congress and Exposition in Detroit on February 27 ~o March 3, 1978.
The reference of interest is Paper 780374:
"Temporary Viscosity Loss and its Relation~hip to Journal Bearing Performance, ~ M . L . McMillan and C . K .
Murphy, General Motors Research Labs.
This reference, and many others familiar ~o researchers in the field, ill~strates how commer~ial polymeric Vl improvers of molecular weights from 30,000 and up all show a temporary viscosity loss when subjected to ~hear rates o~ ~05 to 106 ~ec 1. ~he temporary shear loss is ~areater ~or any shear rate s~ith higher molecular .. . . . . .... . . . . . . . . ...

-21~ 9~;

weight polymers. For instance, oils thickened to the same viscosity with p~lymethacrylates of 32,000; 157,000; and 275,000 molecular wei~ht ~how percentage losses In viscosity a~ a 5 x 105 8eC 1 shear rate of 10, 22 and 3240, respectively.
The thickening fluids of high viscosity synthetic hydrocarbons of this invention all have molecular wei~hts below 5000, and so it should be obvious that shear thinning of their solutions would be nil. That is, they will display Newtonian character.
The shear rates developed in pis~ons and gears (equal to or greater than 106 sec 1) is such that, depending on the polymeric thickener used, the apparent viscosity of the oils approaches that of the unthickened base fluids resulting in loss of hydrodynamic ~ilms. Since wear protection of moving par~s ~as been correlated with oil viscosity, it is apparent that the wear characteristics of a lubricant can be downgraded as a result OI temporary shear. The Newtonian fluids of the ourrent invention maintain their viscosity under these use conditions and therefore afford more protection to and hence longer lifetime for the machinery being lubricated.
The currently used polymeric ~hickeners which show temporary (recoverable) shear are also subject to permanent shear. Extended use of polymeric thickeners leads to their mechanical breakdo~m with resultant loss in thickening power and decrease in Vl. This is il]ustrated in Example 5. Paper 780372 (op. cit), "Polymer Stability in Engines" by W. Wunderlich and H. Jost discusses the relationship between polymer type and permanent shear. The mu3tigrade lubri-cants of this invention are not as suseeptible to even very severe mechanical shear.
This same paper also recognizes an often overlooked feature of hi~h molecular weight polymeric VI improvers, i.e., their instability toward oxida~ion. Jus~ as these polymers lose viscosity by shear they are also readily degraded by oxygen with the resultant break-down of the polymer and decrease in viscosity index. The lubri-cating fluids of ~his invention suffer much less change in viscosity index upon oxidation.
Example 10 illustrates the oxidation of a low viscosi~y fluid thickened with 100 cSt. polyalphaolefin and compares it with the same fluid thickened with a commercial VI improver. Example II

~2~8~
further compares the oxidative stability of fully formulated ~ubricants of this invention with two nearly identical lubricant formulat5~ns, except ~hat the latter are thickened with commercial VI ~nprover.
It is clear from the foregoing that lubricat5ng oils of this 5 invention are superior to traditional multi-graded lubricants because of their ~reater resistance to permanent ~hear and oxidatjon. The prolonged "stay in grade" performance of Dur lubricating fluids o~fers advances in durability of machinery using such fluids.
As mentioned earlier, the lack of temporary shear exhi~ited 10 by the lubricants of this invention guarantees optimum viscosity for the protection OI moving parts where hiyh shear rates are encoun--tered. The importance of this feature is widely recognized. In the past, SAE grading (e.g. sAE30)relied only on a measurement of ~he viscosity ol a fluid at 100C under low shear conditions, despite the 15 fact that in machinery such as a crankcase hiyh temperatures and very high shear rates are encountered. This disparity has led to the adoption in Europe of a new grading system wherein viscosities for a certain grade are those measured at 150C and 10~ sec 1 shear rate. This more realistic approach is current]y being con-20 sidered in the United States. The advantages a Newtonian fluidbrings to such a grading system are obvious to anyone skilled in ~he art. The viscosity of a Newtonian fluid can be directly ex~ra-polated ~o 150C under high shear conditions. A polymer thickened fluid, however, will invariably have a viscosi~y lower than the 2S extrapola~ed value, frequently close to the ~ase fluid itself. In order to attain a certain grade under high shear conditions, poly-mer thickened oils will require a more viscous base fluid. The use of thicker base fluids will produce higher viscosities a~ low temper-ature rnaking it more difficult to meet the low ~emperature (51~ for 30 crakcase of 75W for gear oil) requirements îor broadly multigraded oils .
Stated another way, current high molecular wei~ht V]
improvers "artificially" improve the viscosity index, since realistic high temperature high shear measurements are not utili2ed in 35 determining Vl. Viscosity index ls determined by low ~hear visco sity measuremen~s at 40C and 100C. The Newtonian lubricants of this invention not only produce hi~h viscosity index multigraded ,, . ",................... . . . .. . . . .. . .. . . . . . . . . . .

fluids which 8tay "in grade", but the VI and multigraàe ratin~ are realistic since ~hey are not ~ensitive to ~hear.
While the specific compositions exemplified in this patent are fairly precise, it should be obvious to anyone skilled in the art to 5 produce even further combinations within the ~cope of this inven-~ion which wil] be valuable ~ubricants.
ThP following examples illustrate some cf the blends encom-passed by our invention:

ExamPle 1 This example illustrates the preparation of mu]tigraded gear oils utilizing high visc~sity polyalphaolefin ~PAO) as a thickener.
For a 75W-140 gear oi~ the oil mus~ have a minimum viscosity ~ 100C of 24 cSt. and a viscosity of 150,000 cps ~r less at -40C.

A. 75W-140 VISCOSITY GRADE
%
MA~ERIAL A B C D E F G
PAO-IOO 60 57 58 57.5 51 57.5 57 PAO-4 13 12 12.5 25 22.5 ~3 20 Di-isodecyl adipate 16 10 Di-2-ethylhexyl dodecanoate 20 Di-2-ethylhexyl azelate 20 10 20 ~itec E-320 8 Hitec ~-3241 10 Anglamol 6043~ 10 10 10 10 __ XV100, cSt 24.3 24.6 24.2 24.4 21.. 2 24.5 24.3 -40~C vis, cP 126,000 121,000 124,900 125,!00 138,400 145,600 141,600 .
1. Additive pack3ges made by Edwin Cooper Co.
2. Additive packages made by Lubrizol 3. Additive pac~ages made by Oronite 3~1~6 ~. 75W-go VISCOSITY GRADE
For 3 75~-g0 ail the oil must have ~ ~inimum vi6eosity at 100C ~f 13.5 cSt~ ~nd ~ vi6cosity ~f 150,000 cP. or less ~t -40C.

S ~ ERIAL A B C D lE F G
~?AO-100 48.5 45 41.5 6,l.0 43.0 39 PAO~40 66 PAO-4 4 21.5 25 28.5 27.0 27.0 31 Diisodecyladipate 20 20 20 20 Di-2-ethylhexyl Jzelate 20 19.5 Di-2-ethylhexyl didodecanoate 20 Hitec E-3201 10 10 10 An~lamol 6043 10 10 10 Elco 7 12.5 __ KVloo~ cSt lB.6 20.3 18.4 14.1 15.3 15.4 13.9 Vl 149 ~66 169 ~1~1 172 177 170 -40C vis, cP 141,200 106,900 78,~00 38,050 50,400 49,150 32,~00 _ .
1. Additive package made by Edwin Cooper Co.
2. Additive package made by Lubrizol Corporation 3. Additive package made by Elco Corporation .~

o25-~-z~
C. 80W-140 VISCOSITY GRADE
~or ~ 80W-140Oil the oil IDUst have ~ ~inimum vi~c~ y ~ lOO~C of 24 ~St. and ~ vi~c~sity ~f 150,000 cP. or l~ss ~t -26C.

WT X
5 ~ATERIAL A B C D E
. _ PAO-100 56 55 5~ fiO 52 PAO-60 67.6 PAO-2 4.4 12 10 10 Diisodecyl ~di~ate 20 20 20 20 Diisooctyl ~dipate Di-2-~thylhexyl azel~te 20 Diisodecyl azelate 20 Hit~c E-3201 10 8 15 A~g. 99 10 Ang. 6004A2 10 Ang. 6~43 ~O 1O
__ KVIOO' cSt 26.025.2 24.2 24.~ 24.6 24.7 20 Vl 167 159 167 ~70 i69 16~
-26C vis, cP 65,~00 82,740 60,200 ~2,~50 6~,440 63,610 1. Additive packag~ made by Edwin ~ooper Co.
2. Additive packages (Angl~m~13 made by Lubrizol Example 2 This example il3ustrates the preparation of an ISO VG q60 industrial gear lube which requires a viscosity at 40C between 419 and ~06 cSt.
~ient Wt. %
PAO-1ûO 77 P~0-4 10 Diisodecyl adipate 10 ~S49241}~ 3 addi~ve package from Lubrizol ~.~, , .\, , .. . . .

-~6-``` 12~ 6 It had the following viscometrics KV100 - 44.8 cSt KV~o ~ 414 . 3 Vl - 165 VIS @-26C - 78,600 cP.

Example 3 This example illustrates preparation o~ gasoline and diesel crankcase lubricants.

~ %
10 ~ATERIAL A B C D_ E F G H
PAO-100 20 28 28 28 32 25 20 ]8 PAO-4 42 47 34.5 34.5 47 37.5 42. 54 Di-2-ethylhexyl azelate 20 10 20 10 20 10 Hatcol 29341 20 iHercolube 4012 20 OS61906 17.5 17.5 17.5 LZ 39404 1~

__ k~'100' cSt 10.2 13.2 13.2 13.2 13.6 13.2 9.9 10.0 vis grade 5W-30 10W-40 10W-40 15W-bO 10W 40 15W-40 5W-30 5W-30 1. Available from }latco division of Grace Co.
2. Available from Hercules, Inc.
3. Additive packages made by Oronite.
30 4. Additive packages made by Lubri~ol.

Example 4 This example illustrates the excellent oxidative stability o~ gear oils utilizing high molecular wei~ht PAO.

:~l2~

A 75W-90 gear oil preparcd as in Examp3e 1. B . D . was su~-jected ~o the CRC L-60 Thermal Oxidaffon Stability Test. ln this test 120 ml ~f oil are heated to 325+1~F and 11.1 Iiters/h~ur of air are passed tllrough the fluid. ~he surface of the fl~Lid is agitat~
S a gear running at 2540 Rpm. A 4 sq. in. copper catalyst is ~ nersed in ~he fluid. After 50 hours, viscosi~y change, acid no., benzene and pentane insolubles ~re determined. The resul~s for this Iluid are:
change in KV1oo 12.0%
Acid No. 3.18 pentane insolubles, wt % 0.34 benzene ins~lubles, wt % 0.25 Military requirements are change in KV1oo less than 100%, pentane insolubles less than 3%, benzene insolubles less than 2%.

Example 5 This example illustrates the resistance to mecllanical shear of gear lubricants thickened with high viscosity PAO.
A. A 75W-140 gear oil as prepared in Example 1.A.B was 20 subjected to the Cannon Shear Test. In this ~est the ~luid is subjected to preloaded tapered roller àearings running at 3450 r.p.m. A~ter 8 hrs. under these conditions this fluid lost less than 0.4% of its viscosity.
KV1~o, initjal -24.93 cSt.
KV1oo, final -24.84 cSt.
B . A 75W-140 gear oil as prepared in Example 1. A . B was used ~o fill the drive axle ~f a Class 8 line haul truck. After 30,000 road miles the viscosity was essen~ially unchanged.
KV1oo, initial -24.88 cSt.
~0 KVloo, 30,000 n~i. -24.84 cSt.

ExamDle 6 This example fllustrates the Newtonian character of ~ear lubri-cants and engine lubricants thiclcen~d with PAO-100.

.. . . . . . . . . . .

~2~ 6 A . A gear lubricant as prepared in Example 1. B . D had its v~scosity measured a~ 100C under no shear condi~ions (ASTM
D-445). The ~ame sample's v~scosity was determ~ned at 100C
under a shear rate of 106 sec 1 in a Tapered Bearing Simulator and 5 was essentially unchanged.
B. A crankcase ]ubricant as prepared in Example 3.E had its viscosity measured a~ 150~C under no shear conditions (ASTM
D-445). The same ~ample's viscosity was determined at 150C
under a shear rate of 106 sec 1 in a Tapered Bearing Simulator and 10 was essentially unchanged.

Example 7 This example illustrates the oxidative stability of blends of 100 cSt. PAO and low viscosity PAO. The low viscosity fluids were 4 and 6 cSt. polydecenes. The blends were stabilized with 0.75 parts per 100 of oil (PHO~ of p-nonylphenyl alphanaphthylamine and 0.25 PHO of dilaurylthiodiproprionate. They were subjected to a 370F
temperature for 72 hours while air was passed through the solutions at a rate of 5 liters per hour. The oxidation was performed in the presence of Mg, Fe, Cu, Al and Ag meta] specimens. At the end 20 of the test period, the solutions were filtered and the amount of hexane insoluble sludge formed (expressed as mg. per 100 ml.) was determined for each. The results are summarized in the following table .

Sludge (mg/100 ml) 25 PAO 4 6 100ObservedPredicted% Reduction ~, 100 - - 676 % - 100 - 322 3b - - 100 2 "b 75 - 25 42 507 -92h % - 75 25 23 242 g0~
% - 25 75 2 81 -98%

Even though low viscosity PAO's are noted for their stability, it is evident that the blends with high vlscosity PAO are more stable than would be predicte~ by simple additivi~y. In the a~ove

8~L96 example, the addit~on of 25% PAO-lOO ~o 4 or 6 c5~. PAO gave blends which produced only 10% of the slud~e expected from oxida-tion. The mechanism by which the high viscosi~y hydrogenated PAO's of this ~nvention "protect" lower viscosity fluids, as seen in S this example, is not understood.

Example 8 This example illustrates the viscosity index improvement achieved by blendiny the high viscosity synthetic hydrocarbon~
(represented by lOO cSt. PAO) and low ~nscosity synthetic hydro-lO carbons (represented by 4 and 6 cSt. polydecene) of this invention.

PA0 viscosity Change (100C) 2 4 6 100XV100 VI in ~il X in Blend 100 - - _ 1. 89 - - 10 2.50 136 - - 25 b.54 186 - - 50 12.07 lB7 % in Blend - 100 - - 3.99 119 - 90 - 105 . 60 150 ~26 - 75 - 259 . 10 162 ~32 20,~ in Blend - - 100 - 6.05 132 - - 90 10 8. 15 146 ~1 1 - - 75 25 12.61 152 ~12 - ~00 101 1~5 The viscosity indices obtained by blending low and high 25 viscosity produce a much bigher V. 1. than predic~ed by straight ex~rapolation. The change in Vl in the above chart is a measur~ of the enhancement of Vl over th~t expected by simple additivity.
ln essence the table illustrates the preparation of hydrocarb~n base fluids having V . l . 's higher than any commercially available 30 PAO's In the viscosity range 2-lS cSt. It is thi~ unexpecîedly large enhancement of Vl wh;ch permits the blending of Newtonian multigraded lubricants. This effect is further illustrated in Example (9~-u .~ ~
., ~,. . . . . . . . . . . . . . . .

~30-This Example (8) also ~llustrates the feature that V. I .
enhancement is ~he greatest when the viscosities o~ the b~end com-ponents are ~arth~st apart.

Example 9 This example is similar ~o Example 8, but Illustrates V.1.
enhancement achieved by blending high viscosity PAO (100 cSt. ) with each of two di~ferent esters.

Dii600ctyl Ditridecyl Change Ingredient AdipateAzelate PA0-100 KVInn~c VI in V.I.
10 % 100 - - 3.~3 141 - 10 5.05 171 ~28 - 25 ~.30 182 ~35 - 100 - ~.96 139 - 90 10 4.25 1~9 l34 - 75 2~ 7.21 191 ~46 These data il]ustrate the Vol~ enhancemenL shown in Examp]e 8 is valid in ester blends also. The higher V.l.'s of the pure esters contribute to the remarkably high V . l . 's obtained with ester-PAO
blends. The high V.l.'s of such l~]ends are mani~ested in the final 20 lubricants of this invention (as shown in Examp]e 1 ) and result in extremely good viscosity properties at low temperatures.

Example îO
This example compares directly the oxidative stability of a base fluid ~hickened with a so~nmercia] V . l . Lmprover (ECA 7480 from 25 Paramin's Division of Exxon) ~o that o~ ~he same base ~luid thickend with a high viscosity iynthetic hydrocarbon (100 cSt. PAO). The base fluid chosen as the medium to be thickend was a polydecene having KV219OF of i.96 cS~. and a V.l. o~ 13&. The so]u~ions were stabilized with 0. 5 P~IO oî phenyl alphanaphthyl amine and 0 . 25 30 PHO uf dilauryl thiodipropionate. The oxidation test was performed as described in Examp]e 7. A comparison o~ the ~olutions before and after testing is summarized in the following table.

~; ~
,.
. /

-31~

Fluid Composition, Wt ~ KV210 V.l.
A. 6 cSt. PA0 - 90 Before Test g.61 165 After Test 6.64 134 B. 6 rSt. PA0 - 90 100 cSt. PA0 - 10 Before Test 7.94 149 ~fter Test 8.21 147 -C. 6 cSt. PA0 - 75 10~ cSt. P~0 - 2j Before Test 12.34 153 Afte~ Test 12.78 151 As can be seen, in composition A. the polymeric thickener decomposed drastically. The viscosity after testing was nearly equivalent to that of the starting base fluid. The viscosity index of composition A decreased to that of the base fluid, illustrating 20 ~hat oxidation, as well as shear, destroys the V . I . improvemen~
gained by the use o high molecular weight polymeric additives.
Compositions B. and C., on the other hand, experienced mini-mal change in viscosity and viscosity index, illustrating the oxida-tive stability of blends of the high and low viscosity synthetic 25 hydrocarbon of this invention.

Exam~le 11 This example illustrates the fomulation of finished crankcase Iubricants of the inventi~n and compares their oxidative stability with nearly identical formulations utilizing commercial high molecular 30 weight polymeric thickeners. The ~luids were oxidi~ed under the same condi~ions as were described in Example 10.

-~2-g~
COMPOSI~ION 1 I-A l l -B l l -C 11 -D l l -E
Wt. X A 32 Wt. X B 19 Wt. 'b C 20.5 Wt. X D 17 wt. ~ E ~2.25 Wt. ~, F 47 60 58.5 62 66.75 wt. % G lo lo lo 10 10 wt. % H ~1 11 11 11 11 10 I~PHO)I 0.5 0.5 0.5 0.5 0.5 Ingredients A, B and C represent the thickeners of this invention. Ingredients D and E represent com;nercial high molecular weight V . l, improvers .
A is a 100 cSt. hydro~enated polydecene.
B is a 265 cSt. Iiquid ethylene-propy3ene oligomer having 49 weight % propylene G is a 245 cSt. hydrogenated polyi oprene oligomer.
D is Lubrizol 7010, a commercially available hi~h molecular weight olefin copolymer (OCP) V.l. improYer.
E is Acryloid 954, a migh molecular weight polymethacrylate sold by Rohm and Haas.
~ is 4 cSt. polydecene sold by Gulf Oil Co.
G is Emery 2~58, di-2-Ethylhexyl azelate.
H is Lubrizol 4856, a CD-SF crankcase package sold by Lubrizol Corp.
I is LO-6, an alkylated phenyl alphanaphthylamine from Ciba-Geigy .
The viscometric properties OI ~luids 11-A, 11 B, 11-C, 11-D
and 11-E are compared in the following ~able before and after subjection to oxldation at 3?0F as described in Example 10.

* ~rade Mark ~lL2~
AGED LUBRICANTS A&ED LUBRICANTS
% Change XV~0O,,c RV40oC V. 1. 100C XV4Doc V- I V. I .
ll-A 12.43 79.28 162 14.6393.17 164 ~1%
lI-B 12.~3 75.27 172 14.6191.55 ~66 -3.5%
l~-C 12.55 76.07 164 14.3294.87 156 -5%
ll-D 12.70 68.50 188 10.936~.60 150 -20 1 l-E 14 . ~1 68 .14 230 22 . Oû 130 . 98 196 -15~b The fluids of this invention (11~A, 11-B and 11-C) can be 10 seen to be far more ~table to oxidatisn than nearly identical fluids prepared using comrnercial V.I. improvers. The inherent instability of 11-D and 11-E is evidenced by the large changes in viscosity and large decrease in viscosity index suffered by these fluids.

Example 12 The example compares the oxidative stability of a low viscosity fluid thickened with a variety of ethylene-propyJene polymers, each having a different viscosity and molecular weight. The low vis-cosity fluid chosen was a commercial polydecene oligomer having a kinematic viscosity at 100C (K.V.loo) of 3.83 cSt. One hundred 20 ml. of each fluid was heated to 370~ ~or 72 hrs. Air was bubbled through ~he samples at a rate of S liters per hours. Metal washers (Mg, ~e, Ag, Cu, and Al~, each having a surface area of 5cm2, were suspended in ~he fluids as oxidation catalysts and as speci mens to determine corrosivity of the oxidized fluids (by weight 25 change). Each sample was pro~ected with exactly the same pro-prietary antioxidant. ~eparate studies have shown that the poly-decene base fluicl is extremely well protected by the antioxidant used. After oxidation, the amount of particulales (sludge) formed was weighed, the acid number of the oils was measured, ~he vis-30 cosity changes o~ the samples were determined and any weightchanges in the metal specimens were mea~ured. A zero ~hange in all these parameters indica~es no oxida~ive degradation. The fol-lowiny tables outline the oils testeà and the results of the oxiàation test.

TABLE IA
Properties of Unaged Blends ThicknerwtZPA0-"4" wt% K V loo ~:40 V.l.
o 100 3.~3~6.90 119 ~ 57 43 25.42199.60 160 B 49 51 32 . 55240 . 20 180 C 40 ~0 32.33242.74 177 D 31 69 24 . 25145 . 20 200 Where:
A is a liquid ethylene-propylene copolymer having a vis-cosit~ OI 92 cSt. ~t 100~
B is a liquid ethy]ene-propy~ene cDpolymer having a vis-cosity of 190 cSt. a~ 10ûC
C is a liquid ethylene-propylene copolymer having a vis-cosity of 409 cSt. ~t 130C
D is a colNnercially available viscosity index improver con-sisting of a solution of high molecular weight elhylene-propylene coplymer rubber dissolved in a low viscosity m5neral oil. The contained rubber in such thickellers is usually 5 to 10 weight %.
The following table illus~rates the viSa~etric-changes which occurred to the above blends after the described oxidation.

TAsLE IB
; Properties of A~ed Blends A~ % ~fter aging Thi~kner K V 100 K.V.40 V K V-10O K V.40 NONE 3.92 17.61 118 ~ 2.3 ~ 4.1 -0.8 A ?4.32 189.7 158 - 4.3 - 5.0 -1.3 B 28.46 207.3 176 -12.6 -13.7 -2.2 30 C 28.53 201.8 181 -11.8 -16.9 ~2.3 D B.51 41.51 188 -64.9 -71.4 -6.0 Clearly, the thickeners of this invention ~A, B and C) are much more stable to viscosity and viscosity index losses from oxida-tion tJh an ~e curren~ commercial thickener (D) . The viscosity .~, 35 1lZ~83L9~;

losses observed in this test increase as the molecular weight sf the thickener increases and decrease when a~ a ~iven molecular weight, the amount of thickener used decreases. Samples B and C illus-~ate this,while C is a higher molecular weight thickener S (Mn ~ 1625), than B (Mn = 1360), the fact that C is employed in a lDwer amount to produce the same viscosity in the blend counterbalances its inherently ~rea~er tendency to lose viscosity and both B and C perorm sirnilarly in ~he test. Sample D, on the other hand, actually contains only about 2~3% high mGlecular weight thickener, but the molecular weight is so hi~h relative ~o A, B and C that its degradatinn produces much more severe viscosity losses.
At the o~her extreme, sample A is qui~e low molecular weisht and so suffers very little change in viscosity despite the large amount of thickener used in its blend. Thus ~he fluids of this patent, having viscosities up to 1000 cSt. at 100~C are shown to have outstanding resistance to oxidative breakdown when compared with currently available thickeners.
In addition to viscosity changes, the relative resistance toward oxidation of the blends is illustrated by ~he acid developed (mea-sured by acid number) during aging, the particulates (sludge) formed during the test and by weight change of the metal specimen~. The following table ~eatures data on these parameters:

TABLE I C
Aged Slud~ewt. change, ~g2~pe~i~en 25 Thickener Acid No. mg/lOOml.
(none) 0.20 2.0 0 A 2.7 5.3 -0.18 B 4.4 0 -0.02 C ~.7 0 ~0.0~
D 8.6 2,20D -1.88 Again the acid build up, metal attack and, especially, sludge production found in sample D only, dramatically demorlstrate its inferiority to the examples (A, B and C) of our invention.

This example illustrates the thickeniny power and V . l ., irn-provement of ahe oligomers of this inven~iorl.

., ~ .

8~6 One way OI comparing thickenin~ power is to ascertain the visco~ity increase caused by the addition of a certain percentages of ~hickener to a common base stock. The base fluid used in this example was a polydecene of K.V.1~o 5 3.83. In all Æases, 25 wt.
5 % thickener was added, with the following results.

Thirl~ener K V.10O ~n K-V'I00 blend A 92 1090 9.12 B 190 1360 12.C2 C 409 1650 16 . 32 D 83~ 1890 20.46 E - - 17.16 Thickeners A, B, C, and D are ethylene-propylene oligomers of this invention. Thickener E is Lubrizol 7010, a commercial "OCP"
thirkener coJIsisting of an oil solu~ion of a rubbery high molecular 15 weight ethylene-propylene copolymer. The viscosity of Lubrizol 7010 is given as abou~ 1000 cSt. at 100C.
Clearly, at the hi~her viscosities encompassed by this in-vention ~500-1000 cSt. ), the described oligomers are equal to or even superior to commercial thickeners and as illustrated in Example 2~ 1, all will have greater stability.
Another way of examining thickeners is to compare how much additive is required to increase the viscosity of a fluid to a given value. In ~he following table, the low viscosity polydecene was thickened to 13 cSt. and 24 cS~ with each of the thickeners listed 25 above.

Amount required to thick~n 3 . 83 cSt . polydecene . (wt. %) Thickener 13 cSt. 24 cSt.

B 26 . 5 40 . 5 C 22 34 . 2 D 17.5 ~8 E 20.5 31 Once again fluids of this invention can be ~o chosen as to 35 require ~maller amounts to thiclcen low viscosi~y fluids to a given , .. . . . . .. .

~Lziol8~96~
higher viscosity (1:~ vs. E). While thickeners A, B and C require higher trea$ levels than E, they are surprisingly efficieJIt thiclc-eners f~r their viscosity and as stated earlier produce a more stable blend .
S The following da~a i11ustrate the V.~. improvemenl~ properties of the oligomers ~f this invention in ~e preparation of 24 cSt.
fluids useful as base oils for the preparati~n of multigraded lubri-cants such as SAE 140 ~ear oils.

wt.% ~dded 10 Thickener to 3.83 cSt. Pol2~ecene* ~ V ~0O V I.
B 40.5 24.07 1~0 C 34.2 24.31 180 D 28 24.24 184 * as deseribed earlier in thi~ ex~mple As stated earlier in this patent a viscosity index of 149 is the minimum required for a 75W-140 multigrade gear ~il Clearly all the fluids of this invention qualify easily in this regard. Later ex-amples wil] show that the low temperature properties predicted for 20 these fluids are actually attained.

~xample 14 This example describes the preparation of an SAE viscosity grade lOW-40 diesel crankcase oil using a liquid ethylene propylene oligomer having a kinematic viscosity at lOO~C of 432 cSt.

lngredient wt X
Ethylene-propylene oligomer 18 Lubrizol 48S6 12 The lubricant has the following properties -KVl~o - 14.4 cSt.
KV40 - 87.5 cSt.

CSS@ - 20C 3215 cP

..... .. ..
.. ", ,~,.. .. ..................... . .. . . . . .

Example 15 This example describes the prepara~on of an SAE viscosity ~r~de 75W-lflO automo~ive ~ear oil using a licluid ethylerle propylene oligomer having a kinematic viscosity at lOO~C of 432 cSt.

lngredient wt X
EthyleDe-prGpylene liquid 32 P~D-4 * 58 Angla~ol 6043 10 The lubricant has the properties shown:

KVloo - 24.3 cSt KV40 ~ 160.8 cSt Vl - 1~4 Viscosity at -4 oc= 9 7, 6 5 o cP .

Example 16 This example describes the preparation of an SAE viscosity grade lOW-40 diesel crankcase lubricant using an ethylene propylene oligomer having a kinematic viscosity at ïOOC of 945 cSt.

- Ingredient wt %
Ethylene-propylene liquid 12 Di31ky1 benzene 20 Lubriz~l 3940 18 The lubricant has the properties shown:
KVloo - 13.2 cSt KV40 ~ 78.0 cSt CSS at -20C _ 3260cP.

~xample 17 This example illustrates the preparation of an autsmo~ive gear 30 lubricant SAE viscosity ~rade 75W-140 using a liquid ethy~ene-propylene oligomer having a kinematic viscosity at 100C of 265 cSt.

* Trade Mark -3~-~ ~Z~38 9~
~ngredient wt %
Ethylene-propylene liquid 36 Di-2-ethyl hexyl Dzelate 20 5 Angl~o1 6043 lO
Th~ Jubricant has the properties shown:

KV1oo - 24.87 cSt KV40 - 161.1 cSt Brookfield ~iseosity at-40C = 88,700cP.

Example 18 This example illustrates the preparatjon of a diesel crankcase lubricant SAE viscosity grade lOW-40 using a liquid ethylene-propy-lene oligomer having a Icinematic viscosity at îOO~C of 945 cSt.

In8redient wt X
Ethylene-propylene liquid 14 Di-2-ethyl h~xyl azelate 20 Lubri~.ol 3940 18 The lubricant has the properties shown:
KV1oo - 13.4 cSt.
~V4~ - 80.4 V;~I. - 170 CCS @ - 20C ~ 2920 CP.

Example 19 This example illustrates the preparation of an lSO VG 460 irdustrial 0ear lubricant from an ethylene-propylene oligomer having a kinematic vjscosity at 100C of 945 cSt.

In~redient wt X
30 Ethylene-propylene liquid 42 Diisodecyl 3dipa~e lO
Lubrizol 5034 3 . ,~. . .
~.. .. . , . . j, . . . .

~a2 The lubricant has the properties shown:

KV~ - 59.5 cSt.
~CV40 - 462 ~St.

~!~
This example compares the cxidative stability of fully formu-lated crankcase oils utilizing the hydrogenated polyisoprenes of this invention with essentially identical formulations thickened to the same viscosity with two commercially availa~le high molecular weight 10 ethylene-propylene rubber based thickeners and a purchased sample of hi~h quality crankcase oil. ~One hundred ml. of each fluid was heated to 370~F for 72 hrs. Air was bubbled throu~h the samples at a rate of 5 liters per hour. Metal washers (Mg, Fe, Cu and Al), each having a surface area of 5 cm2, were suspended in the 15 fluids as oxidation catalysts and as specimens to determine corro-sitivity of the oxidiz~d fluids (by weight change). Each sample contained a low viscosity polydecene and equal amounts of es~er and additive package. After oxidation, the changes in viscosity and viscosity index were determined as well ~s the weight changes in 20 the metal specimens. The followin~ tables outline the formulations and their unaged viscome~rics as well as the changes wrought by oxidation. The low viscosity synthetic hydrocarbon ~HC) in the blends was a polydecene havin~ a K~V~1oooC of 3.83 cSt. The ester was di-2-Ethylhexyl azelate and the package was Lubrizol 25 4856.

:~2~8~96 T~ble 20A
Properties of the Unaged Blends Thi~kener A B C D
Wt. X ~hick~ner 20.5 17 15 S Wt. % SHC 58.5 ~2 64 Wt. X Es~er 10 10 ID
Wt. % Additive Package 11 11 11 K.V.loooC 12.55 1~.70 12.54 13.83 K~V~40oc 76.07 68.50 67.99 93.09 10 V.I. 164 188 186 151 A was a 245 cSt. hydrogenated polyisoprene.
B was a commercial thickener.
C was a different commercial thickener.
D was a premium m~tor oil.

After oxidation, the viscometric properties of the above fluids were as o~tlined in the following table.

Table 20B
% Change b Chan~e X Change Sample K.V.lo~ K V.l0O K V.40 K.V.40 V.I. ~.I.
20 A 14.32 l14.1 94.87 ~24.7 156 -4.9 B 10.93 -13.9 68.60 to.l 150 -20.2 C 9.34 -~5.5 53.86 -20.8 157 -15.6 D 7.96 -42.4 51.02 -54.2 125 -17.2 Clearly, the composition of the present invention (A), is 25 superior in oxidative stability to prior art B, C and D. As can be seen, composition A suffered no loss in viscosity and minimal change in viscosity index. These features predict much greater "stay-in-grade" performance for the compositions of this invention.
While all samples produced minimal amounts of insoluble 30 "sludge" (]ess than 100 parts per million), and no corrosion to Mg, Fe or Al; Composition A was fourld to produce less corrosion to Cu and Ag than the other compositions. The following table outlines the weight change observed (in mg/cm2) in the Cu and A~ metal specimens for the ~ested formulations.

Table 20C

S ~luidCh~nge C~ m~/cm2Chan~e A~, mgtcm2 -3.46 ~0.10 B -8.52 -1.30 C -7 . 8B -2 .10 D -13.B2 oh.62 lO These findings again indicate the ~reater s~ability of formu-lation A.

Example 21 This example compares the thickening power of the hydro~Pn-ated polyiscprene oligomers of this invention with a commercial 15 "OCP" thickener, Lubrizol 7010, which is a solution of high mole-cular weight ethylene-prDpylene rubber in oil. Solutions made by dissolving varying amoun~s of difIerent thickeners in a low viscosi~y (3.83 cSt. at 100C) polydecene. The dependence of thickening power on viscosity of the thickener is clearly ~een.

20 ThickenerWt. X ~hickenerK.V.loo Bl~nd A 10 5 . 41

9 . 47 22. 10 B 10 6.60 2~ 25 13 . 72 38.21 C ~0 ~.68 lB.31 63 . 61 :D 10 7.~5 22 . ~ I
S0 90.50 1`-,,`, .. j ~ .. ..... . .. .. . . . .. .

-~3~ ~ 8~

E 10 7.10 17 . ~6 69 . B3 A is a hydrogenated polyi~oprene havin~ K.V.loo c 100 cSt.
S B i s " " " " = 245 cSt .
C i~ " " " " = 546 cSt.
D is " " " " - 984 cSt.
E is Lubrizol 7010 as described in Exaople I.

The thickening power of A, B, C and D (the oligomers of this

10 invention) is seen to correlate with the viscosity of the oligomer.
Thickener E, having a vis~osity of about 1000 cSt. at 100C
(greater than even E of the invention) is not as effective in increasing viscosity of the base fluid as are the higher viscosity fluids of the inventi~n. This finding is unexpected.
In addition to their excellent thickening power, the hydrogen-ated polyis~prene oligomers (HPO) of this invention act as viscosity index improvers. The following data show the viscosity index of a low viscosity polydecene (3.83 cSt.) after thickening to 24 cSt. with A, B, C and D.

20 Thickener Wt. % K.V. 100 V- I .
A 52 24 . 09 lS0 s 38 . 5 24 . 26 175 c 29.5 24.31 178 D 25.1 24.14 183 As stated earlier in this patent fluids having the above high viscosity indices can act as base fluids for a great variety of broadly ~raded lubricants.

Exam~le 2?
This example illustrates the preparation of an SAE viscosi~y grade 75W-140 automotive ~ear lubricant using a hydrogenated polyisoprene oligomer of 295 cSt. a~ 100C.

~2~

Ingr~dient Wt. %
HPû 38 P~0-4 52 Anglamol 6043 ~0 The lubricant had the followin~ properties:
KVloo ~ 24.1 cSt.
KV40- 177.4 cSt.
Vl - 166 Vis . Q -90~:: = 142, oo ocP .

Example 23 This example illustrates the preparation of an SAE viscosity grade lOW-40 diesel crankcase lubricant from a hydrogenated poly-isoprene with a kinematic viscosity oi~ 245 cSt. at 100C.

In~redient Wt. %
-Lubrizol 3940 18 The lubricant had ~he follQwing properties:
KVl~o- 14.4 cSt.
K~74(~ - 95.9 cSt.
Vl - ~55 ~CS ~-20~ ~3480cP.

This example illustrates the preparation of SAE viscosity grade 25 lOW-40 diesel crankcase oils using hydrogenated polyisoprene oli-gomers having the kinematic v;scosities at lOO~C shown.

. ~ -45- ~ Z ~ ~ ~ 9 ~

~ ~ .
Ingredie~t Wt.
. ~PO (KVIoo-245) ~8 Di-2-Ethylhexyl a~el3te 20 Lubrixol 39bO IB

H (KVlOO 546) 14 PAO-4 4~
Di-2-Ethylhe~yl azela~e 20 Lubrizol 3940 lB

c. HPO (KVloo-984) ll Di-2-Ethylhexyl ~zelat2 20 Lubrizol 3940 1~

The ]ubricants had the properties shown:
a b c KVIao~ cSt. 13.2 13.2 ~3.3 KV40, ~S~. 81.0 79.5 78.3 Vl ~64 ~6~ 173 C~ 20~C, cP. 3~50 2975 2780 Example 25 This example il3ustrates the preparation of an SAE viscosity ~rade 75W-140 automotive ~ear lllbricant usin~ hydrogenated poly-isoprene oligomers having the kinematic viscosities at 100C shown.

Ingredient Wt.
~. HPO ~XV~oo-245) 40 Di-2~ethylhexyl azelate 20 Angl~ol ~043 10 ~2Q~; g~
b. ~P0 ~KV~oo-546) 31 Di-2-ethylhexyl az~late 20 An~ ol 60b3 10 c. ~P0 (KVloo-984) 24 Di-2-ethylhexyl azelate 20 Ang1smol 6043 10 The lubricants had the properties shown:

n b c ~VI00, cS~. 24.4 24.2 24.~
KV40, cSt. 173.3 16~.5 160.1 CCS @ - 40C, cP. 132,000 94,300 7B,600 Example 26 Th1s example describes the preparation of an SA~ 10W-40 die~el crankcase lubricant using a hydrogenated polyisoprene oligomer having a kinematic vicsocity of 245 cSt. at 100C.

Ingredient Wt. X
HP~ 20 *Polyol e~ter 68 Lubrizol 4856 12 * A mixed polyol fro~ Humko (Kemester 1846).

The properties o~ the lubricant are ~hown:
KV1oo - 15.2 cSt.
KV40 - 96.5 cSt.

CCS at -20C = 3460cP.

.~

~2~
Example 27 This example illustrates the preparation of an SA~ viscosity ~rade 75W-140 au~omotive ~ear oii usin~ a hydrogenated pslyiso-prene oligomer having a kinema~ic viscosity a~ 1û0C of 245 cSt.

Ingredient Wt. X

Di-2-Ethyi hexyl azel~te 48 Lubrizol 4856 IQ

The lubricant had the following properties.
KV1oo - 24.4 cSt.
KV~go- 167.3 cSt.
Vl 1 7~
Vis. @ -40C = 12~,600 ~P.

_. . , .... . . .. . . . . . .

Claims (8)

1. A lubricating composition comprising:
(A) a polyalphaolefin having a viscosity of 40-1000 centistokes at 100°C, (B) a synthetic hydrocarbon having a viscosity of 1-10 centistokes at 100°C, (C) an ester having a viscosity of 1-10 centistokes at 100°C, and (D) an additive package comprising at least one additive selected from the group consisting essentially of dispersants, oxidation inhibitors, corrosion inhibitors, anti-wear agents, pour point depressants, anti-rust agents, foam inhibitors and extreme pressure agents.

2. A lubricating composition comprising.
(A) an ethylene-alphaolefin, oligomer having a viscosity of 40-1000 centistokes at 100°C, and (B) a synthetic hydrocarbon having a viscosity of 1-10 centistokes at 100°C.

3. The composition of claim 2 further comprising an ester having a viscosity of 1-10 centistokes at 100 °C.

4. A lubricating composition comprising:
(A) a hydrogenated polyisoprene oligomer having a viscosity of from 40-1000 centistokes at 100°C, and (B) a synthetic hydrocarbon having a viscosity of from 1-10 centistokes at 100°C.

5. The composition of claim 4 further comprising an ester having a viscosity of 1-10 centistokes at 100°C.

6. A lubricating composition comprising:
(A) a hydrogenated polyisoprene oligomer having a viscosity of from 40-1000 centistokes at 100°C, and (B) an ester having a viscosity of from 1-10 centistokes at 100°C.

7. The lubricating composition of claim 2, 3 or 4 further comprising an additive package comprising at least one additive selected from the group consisting essentially of dispersants, oxidation inhibitors, corrosion inhibitors, anti-wear agents, pour point depressants, anti-rust agents, foam inhibitors and extreme pressure agents.

8. The lubricating composition of claim 5 or 6 further comprising an additive package comprising at least one additive selected from the group consisting essentially of dispersants, oxidation inhibitors, corrosion inhibitors, anti-wear agents, pour point depressants, anti-rust agents, foam inhibitors and extreme pressure agents.