CA1064011A

CA1064011A - Extreme pressure lubricant compositions and process for making same

Info

Publication number: CA1064011A
Application number: CA221,900A
Authority: CA
Inventors: Josef F. Bergeron
Original assignee: Jet Lube LLC
Current assignee: Whitmore Manufacturing LLC
Priority date: 1974-04-17
Filing date: 1975-03-12
Publication date: 1979-10-09
Also published as: DE2509203A1; GB1505554A; JPS50136304A; BR7501113A; PH11193A; FR2268068B3; AU7900875A; FR2268068A1; US3883439A

Abstract

A B S T R A C T

Disclosed herein are lubricating compounds comprising the reaction product of significant amounts of a fish oil, a sulfur-modified sperm oil, a microcrystalline wax and an oxide of lead, preferably litharge. In one embodiment, the lubricating compounds additionally comprises up to 90% by weight of a hydro-carbon oil which results in an extreme pressure grease lubricant having desirable lubricating properties. Also disclosed herein is a process for preparing the lubricating compounds of the invention.

Description

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The invention relates to lubricatin~ compounds ancl uses therefor. In one embocliment the i.nvention relates ~o ex-treme pressure lubricants employed to reduce wear on movin~ parts suh-ject~d to frict.ional wear under high hearing pressures.
To recluce friction and protect the contactin~ surEaces in, for example, mechanical bearin~s, anti-friction bearings and journals, lubricants such as viscous oils and greases are applied to the contacting surfaces. These lubricants must themselves with-stand the extreme pressure exerted on them by the contacting surfaces witho~t substantially losing their lubricating quality Where extreme pressure greases are involved, it is necessary to provide a gelling agent or thickener which thickens a hydrocarbon oi} and an extreme pressure additive such as compounds of sulfur, phosphorous and chlorine and lead soaps which allows the grease to stand up un~er lubricating conditions. An improved form of such a grease composition is disclosed in United States Patent 3,652,415.
In the lubricating compound of the patent, a grease is prepared by thickening a hydrocarbon oil with a metallic stearate 50ap and adding thereto an extreme pressure proportion oE a fish oil lead ~-soap and a sul~ur-modified sperm oil. It is also known in the art to add o~her extreme pressure agents to lubricating compounds.
Although the lubricating compound of the patent exhibits desirable -~
extreme pressure lubricating properties, it employs a gelling agent as well as an extreme pressure agent in order to achieve ~he d~sired~lubricating colnposition.
.
It is desixable to provide a lubricating compound for use in an extreme pressure environment which does not re~uire the addition of discrete gelling agents and extrerne pressure additives to the same composition. This is desirable not only from the standpoint of econor~y but also from the act that many extrelQe pressure additives interreact with gellation agents so tha-t t11ese agents mutually interfere with their respective functic)ns.

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In many lubricatirlg applications, such as extrcme pressure greases and open gear lubricants, it is desirable to have lubricating compounds ~hich are non~newtonian in nature. Non-newtonian lubricating compounds exhibit a broad apparent viscosity range and this CaTI be usetl in a hroad range oE applications which are not suitable to newtonian fluids~
Moreover, where greases or grease-like lubricants are involved it is also desirable to have a lubricating compound which is thixotropic in nature and has a reversible gel structure, i.e., will regel a~ter melting.
Reversible gel greases and grease-like substances are desirable where it is preerred to apply the lubricating compound as a liquid but for it to be in a gel or gel-like state under operating temperatures and conditions. Most greases, however, possess only a low degree of thixotropicy and have non-reversible gel structures. Therefore, they canno~ be heated above their liquefication or drop point temperature since they are incapable of returning to their gel structure upon cooling. Similarly when such greases are exposed to shear, their gel structure does not completely return when shear is removed.
In view of the foregoing it was desired to provide lubricating compounds having reversible gel structures, which are non-newtonian and thixotropic in nature.
The lubricating compounds of the invention comprise the reaction product of significant amounts of a fish oil, a sulfur-modified sperm oil, a microcrystalline wax and an oxide of lead.
The present invention provides a thixotropic lubricating compound having a gel structure reversible after heating beyond the drop point of the compound, non-newtonian.flow characteristics/ and a broad apparen~
viscosity range, comprising the reaction product of a crude fish oil, a sulfur-modified sperm oil, a microsrystalline wax and an oxide of lead.
The present invention also provides the process for the production of B thixotropic lubricating compound having a reversible gel structure

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comprising the steps of; adding to a reaction vessel a flsh oiL, a sulur-modified sperm oil and a microcrystalline wax; heating the mixture to a temperature of from about 300F to about 400F; adding to the mixture an oxide of lead; and cool;ng the mixture.
A urther embodiment of the present invention provides a thixo-tropic lubricating compound having a gel structure reversible after heating beyond the drop point of the compound, non-newtonian fl~w characteristics, and a broad apparent viscosity range, comprising the reaction product of a crude fish oil, a ulfur-modified sperm oil, a microcrystalline wax and an amount of an oxide of lead in excess of that amount which would be required to react with the crude fish oil to form a normal lead soapO
In some embodiments of the invention the lhbricating compounds additionally comprise a hydrocarbon oil.
In one preferred embodiment the weight ratio of fish oil to the oxide of lead is from about 1:2 to about 2:1; the weight ra~io of the lead soap, i.e., fish oil plus the oxide of lead to sulfur-modified sperm oil is from 1:1 to about 4.4:1; and the weight ratio of the microcrystalline ~ -wax to the lead soap is from about 1:2 to about 6.5:1. -- 2 a -~i 3ig Within the above ratios the amount of microcrystall:ine waX in the compound, on a total compound ~ei~rht percent l)asis, should not exceed from about ~O-~i to about 85~i, at which point the waX ~egins to separate from the lubricating compound. ~7ithin the specified xatio of fish oil to oxide of lead, the oxide is present in a~ amount in excess oE the amount which would be re~uired to react with the ish oil to produ~e a normal lead soap. Pre~er-ably the oxide o lead is present in the maximum amount that will chemically combin2 with the other components o e the lubricating 10 compound. This amount may readily he determined for any particu- -lar composition. Surprisin~ly, even though lead soaps are not good gelling agents, the above composition o ~i9h oil lead soap, micro-crystalline wax and sulfur-modified sperm oil results in a thixo-tropic grease-like lubricatinq compound having a reversible gel structure and which exhibits particularly desirable extreme pressure lubricating charActeristics.
In another pxeferred embodiment of the invention, hydro-carbon oil may be added to the composition to form a lubricating grease having desirable apparent viscosity, thixotropic and extreme pressure characteristics. In this embodiment, tlle hydxo-carbon oil is present in an amount of up to about 90~i of the total wej~ht of the resultin~ lubricating compound.
The lubricating compound of the invention may be prepared according to the following process of the invantion. First, the fish oil, the sul~ur-modified sperm oil and the microcrystalline wax are added to a rea~tion vessel. The mixture is heated to a raaction temperature of at least about 300~. The oxide of lead is added to the heated mixture in the amount set out above. The temperature is maintained in tha range from about 300F to about 400F for a sufficient time so that all of the lead oxîde reacts with the other components of the mixture to form the lubricating compound product. The upper limit of the temperature of the re-action is determined ~y the point at which metallic lead begins ~;4[)~
to drop out of the solukion and may vary dependin~ on the properties oE the particular mixture. The IOWeL- l:imi~ of temt-er-ature is that temperature at which the oxicle of leacl will react with the other components in a signiicant anlo~nt. T~le above compound may then be added, preEerably w.ith heatinq, to a hydro-carbon oil ~o fo~n a grease.
In one embodiment of the invention the lubricating compound comprises the reaction product of a fish oil, a sulfur-modified sperm oil, a microcrystalline wax and an oxide of lead.
The fish oil may be any crude fish oil such as, or example, tuna oil, herring oil, menhaden oil, sardine oil, cod-liver oil, halibut oil, salmon oil, and shark oil. ~he primary requirement is that the particular ish oil employed must be a semi-drying oil, i.e., containing both saturated and unsaturated oils. The ~ulfur- -modified sperm oil may be either synthetic or natural sulfur-modified sperm oil, as for example~ sulfurized sperm oil or sulfonated sperm oil. In one embodiment the fish oil is crude tuna oil, the sperm oil is Lubrizol No. 5003, ~old by the Luhrizol Corp-oration of Cleveland, Ohio, and the oxide of lead is litharge.
The fish oil to oxide of lead ratio may be from about 1:2 to about 2:1 and is preferably about 1~3:1 when litharge is used, the fish oil is crude tuna oil and an extreme pressure lubri-cant is desired. The rat1o of fish oiI to the oxide of lead will vary not only depending upon the particular fish oil employed in ~he lubricating composition but may well vary from batch to batch o~ the same type of fish oil. This result obtains since the quantity of khe oxide of lead required for a particular fish oil is dependent both upon the ~atty aoid content o the fish oil, as ; measuxed by its neutralization number, and the polyunsaturate content, as measured by its iodlne value. The ratio of lead soap to sulfur-modified sperm oil may be from about 1:1 to about ~.4:1 and is pre~erabl~ about 2.3:1 when litharge is used, the fish oil i~ crude tuna oil and an extreme pressure lubricant is ~esired.
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The ratio oE microcrystalline wax to lead soap may l~e frorn a~out 1 2 to ~bout 6.5.1 and is preeerably about 1.3:1 when litllarqe is used, the fish oil is crude tuna oil and an extreme pressure lubri-cant is desired.
q~he lubricating compounds of the invention comprisirlg the reaction product of the above components within the specified ratios are homogenous, solid, grease-like substances havinc3 a gel structure, are thixotropic and exhibit non~newtonian flow character-is~ics. Particular features of the lubricating compounds of the invention are that they are extremely thixotropic in nature and that they will return to their ori~inal gel structure even after they have been heated above their drop point or have been subjected to shear. This is in direct contrast to most lubricants of this type, like conventional greases, which normally are much less thixotropic in nature and do not completely regain their gel stxucture after being subjected to shear. The non-newtonian nature of the lubricating compounas of the invention results in a broad range apparent viscosity which makes them suita~le for use over a broad rangè of applications for which newtonian fluids are no~ ~;
suited.
~ ithin the ratios set forth above the reactantls which orm the lubricating compounds of the invention are selected so that the above-described excess of litharge is present and that the maximum microcrystalline wax content does not exceed about 80~ to about 85% by weight. Above that point the microcrystalline was will not remain a part of the compound bu~ separates out.
Although the exact mechanism by which the lubricatin~
compounds of the invention obtain and exhibit the useful properties thereo~ is not known r it is believed that the non-newtonian nature

3~0 of the compositio~s and the fact that they are thixotropic is related to the xeaction o the oxide of lead with the fish oil : whioh allows close assoeiation to the sulfur ~roups of the sulfur-modi~ied sperm oil. This is belie~ed to allow couplin~J between ., . , . , .: .

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the microcrystalline wax and the ish oil lead 50ap. This reaction is believed to be related to tlle iodin~ number ox polyunsaturatQ
content of the Eish oil in that a portion of the lead is believed to react with the fish oil at the unsaturated ~ites.
In order to obtain the lubricatincJ compounds of the invention the ~nount of the oxide of lead added to the composition is in excess o~ that re~uixed to produce a normal lead soap by direct reaction with the fish oil alone. B~ "normal lead soap" is meant the soap produced by the reaction of a ~ish oil with that amount of an oxide of lead which is necessary to neutrali~e the acid components of the fish oil. When the lead oxide is litharge, the amount in excess is preferahly the maximum amount of litharge that will combine with the ish oil, sulfur-modified sperm oil and microcrystalline wax in the particular composition. As will be appreciated b~ the art skilled this amount may readil~ be deter- -mined experimentally for particular compositions. For example, once the ~uantities of the other reactants is determined a small , sample batch may be prepared and the oxide of lead added thereto until no further oxide will react. Since the oxide is a dense solid which settles out of the mixture the unreacted portion may readily be reco~ered and weighed. The amount of the oxide which ;reacted may, therefore, be determined~
In yet another embodiment of the invention, a hydrocarbon ail may~be added to the lubrlcat~ng compound described in an amount such that the hydrocarbon oil comprises up to about 90~ by weight of the resulting lubricating compound. The resulting composition is~ a :lubricating ~rease ~poss~essing the properties described above.
~mong the hydrocarbon oils suitable for use in compositions oE
this em~odiment of the invention there may be mentioned mineral 30~ oils such~as residual oils, spindal oils, pale oils, neutral oils, b~right stook, black oil and other lubricating oils known to those skilled in the art wh;ch may be untréated, conventionally refined, so1vent treated by known processes and hydroinished ox hydrofined.

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Synthetic olls such as polybutenes, esters and other synthetic oils pr0-dominately composed of hydrocarbons known to the lubricating art also fall within the scope of the term hydrocarbon oil as defin~d herein. Particular oils that may be mentioned are ~I 400* Shell and MVI 150* Shell ~bright stoc~) The exact amount o~ hydrocarbon oil in the total lubricating com-positions of this embodiment of the invention is depandent upon the gelling characteristics of the hydrocarbon and ~he end use desired. For example, where an open gear lubricant is desired9 asphaltic residual oil in an amount of 49.8% of the mixture is added.
The lubricating compounds o the inven~ion may be beneficially employed in a wide variety of conventional lubricating uses. An exceptional characteristic of the lubricating compounds of the invention is that they may be used in extreme pres~ure service as an extreme pressure lubricant without the further addition of any of the usual extreme pressure additives beyond what is necessary to form the gel structure. Ordinarily, to obtain greases useful in an extreme pressure environment it is necessary to add gelling agents as well as extreme pressure additives to the grease com-position. However, most extreme pressure additives and gellation agents known to~the art, when presen~ together in grease compositions, interfere with each other's ~unctions. Thus9 the effectiveness of both agents is reduced~
Commonly used gelling agents are the metallic stearate based soaps, and in a known composition a fish oil lead soap and sul~ur-modified sperm oil extreme pressure agent is added to an oil thickened to grease consistency with a metallic stearate-soap. However, in the lubricating compounds of the in-vention herein, it is not necessary to employ a me~allic stearata soap or other gelling gent. Rather, surprisingly, it has been found that the :: :

* Trade Mark - , .: , ., . , ~;, . . : . . , 10~;40~Ll lubricatin~ compounds of the :invention may functlon in e~treme pressure environments as extreme pressure lubricallts without the addition of any other gellin~ agents or extreme pressure additives.
The lubricating compounds of the invention may be pre-pared according to the process o~ the invention by the following steps. First, the fish oil, sulfur~modified sperm oil, arld micro-crystalline wax is added to a reaction vessel. The mixture is then heated, with mixing, up to the reaction temperature which will vary depending on the properties o~ the components. For example, when the fish oil is crude tuna oil, the mixture should be brough~ to a temperature o~ from about 300~ to about 400F.
The upper limit of the temperature is determined bv ~he point at which the oxide of lead to be added in the next step of the xeaction drops out of the reaction product as metallic lead. The lower limit is determined by the point at which ~he oxide of lead will not xeact at a significant xate with the other components.
Next, an oxide of lead is added to the heated mixture in an amount in e~cess of that which will form a normal fish oil lead soap as described above. Preferably, the oxide of lead is present in the maximum amount that will react with the mixture.
The components are allowed to react to form the lubri~ating com-pound for a time sufficient tv react all of the lead vxide present or until no further lead oxide will react. The reactio~ product is thell ~ooled to form a solid grease-like substance. In one embodiment of the inven~ion the grease-like substance may be mel~ed into a hydro~arbon oil which may form up to 90% by weight ; of the resulting mixture. Alternatively, the hydrocarbon oil may be added to the ho~ mixture. In elther case the mixture is cooled to form a lubricating grease~ -The lubricating compoun~ of the invention may be emplo~ed in a wide variety of lubxicating uses due t~ the many desirable properties exhibited by these lubricating compounds as desc~ibed above. The reversible gel nature of the compounds allows 1~6~
them to be applied as a liquid which is de~iral>le in many applica--tions such as open gaar lubrication. The lu~)ricatin~3 compounds oF the invention are particularl~! use~ul in extreme ~ressure applications in that they meet extreme pressure speciications without the addition of ~ny additional extreme pressure additives or any other gellation of thickening agents. Thus, there is obtained in one composition a lubricatinq co~lpound which possesses both highly desirable thixotropic and reversible ~el properties, as well as extreme pressure properties. Particularly in the com-pounds of the invention containing h~clrocarbon oil, an extremepressure grease is obtained which does not require the addition of a metallic steara~ soap or any other thickener or any additional extreme pressure agents.
The lubricating compounds of the invention a:Lso exhibit excellent resistance to a~ueous fluids such as would be encountered in operations exposed to salt water sprav or steam cleaning. The thixotropic property of the lubricating compounds and the high apparent viscosity associated therewith prevents dust and dirt from becoming embedded in the lubricating compounds. The lubri-20 cating compounds also displace water on the surfaces to be lubri-cated thereby wetting the bearing surface~ with the lubricating compound.
More dilute versions of the luhricating compounds of the invention ma~ be used as cable steel lu~ricants since the properties of the lubricating compounds allows them to be carried to the core of the cable. This property is especiall~ useful where steel cables have a hemp core. The extreme pressure properties also make some compositions suitable for large slow moving rolling el ment be~rings.
It is within the scope of the invention to add to the lubricating compounds of the invent~on, additives well known to the art to obtain particular ~roperties desirable for some appli-cations. For example, mol~bdenum disulide, tungsten clisu:Lfide, g_ . ~ . ~ . . .

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zinc oxide and graphite may be added to t.h~ lubricating compound to impart low starting torque properties to t:he lubricAt::in~ com-pound.
The lub.ricating compouncls and proce!sses of ~he invention are further described in the follow.ing exampl.e whe~ein all parts b~ weight and all de~rees in degrees fahrenheit unless otherwise specified. In the examples the symbols used to express ratios of the reactants have the following meanings:
Fo identifies fish oil;
__ SSO identifies sulfur-m~dified sperm oil;
L identifies litharg~;
MCW identifies microcrystalline wax; and FOLS iclentifies fish oil lead soap which is the weight total of fish oil and litharge in the composition~
Unless otherwise specified, the fish oil in the follow ing examples is crude tuna oil wherein the carbon chains are normally C14 to C24 ~nd which is a product of Van Camp Cannery, Los Angeles, California; the sulfur-modified sperm oil is Lubrizol ~.
5003; the litharge is commercial grade; the microcrystalline wax is a mixture of commercial waxes having a 120 melting point; and the residual oil is #1 residual oil produc~d by the Newhall , refinery at Newhall, California, having a viscosity of about 1050 SSU at 150F. Residual oil was chosen since it is one of ~he most difficult hydrocarbon oils to gel. -:

: EXAMPLE I

A lubricating compound having the following composition was prepared.

COMPONENT WEIGHT (OZ.) RATIOS

: Fo ` 13.0 Fo/L 1.3:1 3D MCW 30.9 MCW/FOLS 1.34 SSO 9.9 FOLS/SSO 2.3:1 L 10.0 tra~le marK

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The crude tuna oil, microcrys-talline ~rax and sulfuri~ed sperm oil wereplac~ed in a reaction ~essel and heated to a~out 300F. ~t the point the litharge was sprink:Le~ in the mixture and the mixture was maintained bet~een about 310~F to about 340F Eor about 1 hour while the reaction proceeded. The mixture was then cooled. The resulting lubricating compound was a hard, wax~, grease-like solicl, which when exposed to shear stress rernained a grease-like semi-solid. This is a preferred compound of the inven-tion and was used as a standard of comparison in the following example.
The above lubricatiny compound was then melted into an equal weight of residual oil which resulted in a gelled grease.
The grease composition possessed excellent extreme pressure and thixotropic proper~ies which render it suitable for use in appli-cations reyuiring a N~GI #6 classified lubricating grease and particularly an extremP pressure lubricatin~ grease. This compo-sition represents a preferred embodiment o~ the hydrocarbon oil containing lubricating compound of the invelltion.
EXAMPLE II
A mixture was prepared from the following components.
CO~IPONEMTWEIGHT tZ ) RATIOS
.
E'o 15.1 Fo~I, 1.3:1 MCW 36.0 MCW/FOLS 1 ~ 4:
~SO 1.4 FOLS/SSO 1~:1 L 11.5 The crude tuna oil, microcrystalline wax and sulfurized sperm oil were introduced into a reaction vessel and heated with mixing until the mixtur~ reached about 300. ~t this point lithar~e was spxinkled into the :mixture and the mixture ~as main tained at between 310~ and 340 for about 1 hour as the reaction prt~ceededO The mixture was then cooled~ The resulting cooled composition was not homogenous in nature~ Rather, wax was observed - to separate ~rom the xest of the mixture . The composi tion exhibited . .

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unac~ceptable lubricating compo~mcl properties. I~ order to ohtain a lu~ricatin~ compound with more acceptable lu~)rlcatinc3 properties, the above compositlon was mixed with an equal wcight of the non-residual oil containing lubricating composition of ~X~'ilPLE I giving a mixture with the following proportions and ratios:
COMPONENT~ EIGI~T (02 . ) R~ IOS
Fo 28.1 Fo,/E 1. 3 :1 MCW 66 . 9 MCW~FOLS 1. 3: 1 SSO 11. 3 FOLS/SSO 4. 4:1 :~ 21.5 The resultin~ mixture ~xhibited lubricating properties in the just acceptable range. A part of that mixture was melted into an equal part of residual oil which produced a gellecl grease.
The gel structure was mealy in nature and the shear stability of the grease was low as measured on a Porti~is viscosimeter. The mixture had an initial viscosity of more than 400~ poise (the measuring equipment could not measure above 4000 poise). After five seconds this viscosit~ was reduced to less than 700 poise.
The foregoing example demonstrates the approximate upper limit of the ratio of lead soap to sulfurized sperm oil in a composition employing crude tuna oil as the ~ish oil of the lead soap. As will be readily apprecia~ed by the art skilled, other maximum ratios may be established using other fish oils. It is within the scope of the invention to include other ratios of lead soap to sulfurized sperm oil where different fish oils are employed.
EXAMPLE III
; A lubricating compound ha~ing the ~ollowing components was prepared.
COMPON~NTW IGEIT RATIO
Fo 11 Fo/L lo 4 1 MCW 30 MCW/FOLS 1.6:1 SSO 19 FOLS/SSO 1:1 . . ~ . - - - . : - ~ ~. .

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The crude tuna O.ilr microcrvstalline wax and sulfurized sperm oil were placed in a reaction vessel and heated with stirrin~
to about 300. Lithar~e was then s~rinkled into the mixture which was maintained between 310 and 340 for about 1 hour un~il the reaction h~d gone to completion. The mixture was then cooled to ambient temperature. The resulting lubricating compo~md was a hard waxy solid which, when subjected to shear, quicklv ~eoame a tacky liquid. The lubricating compound was melted into an equal weight o residual oil. The resulting compound exhibited a weak gel strusture which upon shear gave a tack~ uid.
The foregoing example demonstrates the approximate mini-mum lead soap to sulfurized spexm oil ratio which wîll provide acceptable lubricating compounds when the fish oil is tuna oil.
As will readily be appreciated hy the art skilled this minimum ratio may vary with other fish oils. It is within the scope of the invention to include such variable ratios when other fish oils are employed.
EXAMPLE IV
~ lubricating compound havin~ the following composition 20 was prepared.
COMPONENT WEIGHT RATIOS
Fo 21 Fo/L1. 3:1 :
MCW 18. 5 MCWfFOLS 1: 2 SSO 18. 5 FOLS/SSO 2 :1 The crude tuna oil, microcrystalline wax and spenm oil were introduced into a reaction vessel and heated to about 300.
Litharge was then sprinkled into the mixtuxe which was maintained with stirring between 310 and 340 for about 1 hour~ The mixture was ~hen cooled. The re.sulting lubricating compound was a grease-like substancP having the general consistencv of conventional grease.
Thls compound w~s melted in-to an equal weight of cesidua]. oil re-sulting in a semi liquid compound which indicates some lack of gel ~strength.

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EXAMPLh~ V
A lubricating compound havi.ng the Pollow.ing composition was prepared.
COMPONENTWEIGHT ~ATIOS
Fo 5 Fo/L 17: 1 MCW 52 MCW/FOLS6 . 5 :1 sso 4 rl~oLs~sso 2:

The crude tu~a oil, microcrystalline wax and sul~urized sperm oil we~:e added to a reaction vessel and heated to ahout 300.
At this point litharge was sprinkled into the mixture with stir-ring and the mixture maintained between 310 and 340 for about 1 hour. ~he mixture was then cooled. The resulting lubricating cOmpOuna was a waxy solid. When the compound is melted into an equal weight of residual oil a luhricating:compound having a relatively weak gel structure is produced which quickly returns to the liquid state under shear. ~:
The foregoing example~demonstrates the approximate maxi-, mum ratio of microcrystalline wax to lead soap which will still 20~g~ive~an~acceptable lubricating compound when the fish oil i6 crudetuna:oil. As wilL re~dily be appreciated by the art skilled the use o~alterna~ive fish oiIs within the scope of the invention : may well:result in a different maximum ratio. It is within the scope of the invention to include~compositions having a micro-crystal~line wax to lead soap ratio outside the above ratio when other fish oils are~employed.:
EXP~llPLr VI
A lubricating grease~was prepared according to the process~of the invention having the following composition.

::~ :: : :: ~ :

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COMPONENTWEI('JIlT (~) :RATIOS
Fo 76 . 5 :Fo/L 1. 3 :1 MCW180 . 0 MCW/FOLS 1. 3 :1 SSO5 8 . 5 FO1S/SSO 2 . 3 :1 L 5 7 . 6 ~sphaltic Residual Oil 369.0 In addition 23.4 pounds of MoS2 and 135 pounds of graphite were added to the lubricating grease. The asphaltic residual o:il is 10~ asphalt added to 90~ residual oil. This qrease represents a pre-erred embodiment of the invention possessing all of the desirable characteristics discussed above. It i~ particularly use~u:L as an open gear lubricant.
A lubricating grease cf the invention was tested for wear characteristics by the LFW/l standard load friction and wear test for extreme pressure greases. The grease was prepared in the proportions set forth in EXAMP~E VI but since ~sphaltic residual oils someti~e have natural extreme pressure properties, MVI 150 hright stock was substituted for residual oil in the grease. ~VI
150 was also used in the other comparison lubricants. The test was conducted with a base load of 180 pounds and at 60,000 pounds per square inch. The block material had a hardness o~ 34 Rockwell C and a suxface finish of 15 RMS while the ring material had a hardness o~ 60 Rockwell C and a surface finish of 7 RMS. The test was conducted at 85 rp~ for one hour.
The test results demonstrated that the composition of the invention compared favorably with other extreme pressure lubri-cating gre~ses which contain addltional gelling a~ents or additives not present in the composition of the invention. In particular the wear characteristi~s are significantlY better than those de,monstrated by an extreme pressure grease prepared according to the disclosure of the above-referenced United S~ates Patent 3,652,415.

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The temperature ~nd coefficient of fr:iction curves of the lubricatin~ compound cluring the test also demonstrated clesir~
able properties of the lubricatinq compound. Thus, the temperature increased in the early part of the test and then returned to a lower value and remained steady for the ,rest of the tes~. 5imi~
larly the coefficient of friction decreased a's the t~st continued , , until a sharp downward break was obtained in the curve at from about 2500 to about 3000 revolutions ater which the coefficient of friction leveled o~ at a xelatively low value below .0~.
Similarly the indicated wear demonstrated a leveling off a~ about 4000 revolutions at a level o about .001 inches.
The lubricating compound of the invention also compares favorably with a lubricant formulated with the percentage of addi-tive normall,,v used to pass the Gardner-Denver test for extra pressure lubricants. That test utilizes a pin-type Weeks oil tester and requires that the lubricant pass a 300,000 pound per square inch minimum before rapid wear or pin seizure occurs. How- ' ever, the particular sample was not tested on the machine.
It will be noted that all of the desirable character- ~' istics of e~treme pressure lubricating greases are obtained with the composition of the invention without the addition of any extra gelling agent or extreme pressure additive to the lubricating composition as is required in known extreme pressure lubricant compositions.
Lubricant composltions prepared according to the inven-tion were also subjected to standard AS'rM penetration tests modi-fied,by performing the tests at various temperatures. These tests d~monstr~ted that lubricating compositions of the invention possess penetration/temperature chaxacteristics markedly di~ferent frvm those of conven-tional greases. That is, with conventional greases, ~, the penetration/temperature relationship is substantially linear ,~ or a simple curve depending on ~raph plottin~,techrliques. (Vis-cosity is normally plotted loyarithmically to ~ield linear results).

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The drawing 1~ a ~raph of the penetration -te~perature relationship o the compositions of the pres0nt invention. As will be readily appreciated, this characteristic allows lubricating compositions of I:he invention within a particular NLGI grade to be used over a much oroader temperature range in many applications than comparable lubricants of convent;onal formulations. In open gear lubrication this characteristic is par-ticularly desirable.
The lubricants of the invention may be readily mixed with volatile solvents such as, for example, hydrocarbon solvents, chlorinated hydrocarbon solvents, alcohols, etc, Preferably the solvent may comprise up to abou~ 50%
by weight of the resulting mixture. As will be appreciated by the art skilled, such diluted mixtures may be combined with suitable propellants such as air, fluorinated ethylenes and other propellants known to the aerosol art.
The resulting aerosol spray lubricant is particularly suitable for open gear lubrication appl;cations as well as other applications where it is desirable to apply a lubricant as one would a paint.

-17- ~ :

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A thixotropic lubricating compound having a gel structure reversible after heating beyond the drop point of the compound, non-newtonian flow characteristics, and a broad apparent viscosity range, comprising the re-action product of a crude fish oil, a sulfur-modified sperm oil, a micro-crystalline wax and an oxide of lead.

2. The lubricating compound of claim 1 further comprising up to about 90% by weight of the total compound of a hydrocarbon oil.

3. The lubricating compound of claim 1 wherein the crude fish oil is selected from the group consisting of crude tuna oil, herring oil, menhaden oil, sardine oil, cod liver oil, halibut oil, salmon oil and shark oil and the sulfur-modified sperm oil is selected from the group consisting of sulfurized sperm oil and sulfonated sperm oil.

4. The lubricating compound of claim 3 wherein, the weight ratio of the fish oil to the oxide of lead is from about 1:2 to about 2:1; the weight ratio of the fish oil plus the oxide of lead to the sulfur-modified sperm oil is from about 1:1 to about 4.4:1; and the weight ratio of the micro-crystalline was to the fish oil plus the oxide of lead is from about 1:2 to about 6.5:1.

5. The lubricating compound of claim 4 wherein the oxide of lead is litharge.

6. The lubricating compound of claim 4 further comprising up to about 90% by weight of the total compound of a hydrocarbon oil.

7. The lubricating compound of claim 4 wherein, when the fish oil is crude tuna oil, the ratio of the fish oil to the oxide of lead is about 1.3:1; the weight ratio of the fish oil plus the oxide of lead to the sulfur-modified sperm oil is about 2.3:1; and the weight ratio of the microcrystal-line was to the fish oil plus litharge is about 1.3:1.

8. The lubricating compound of claim 7 further comprising about 50% by weight of the total compound of an asphaltic residual oil.

9. The lubricating compound of claim 2 wherein the hydrocarbon oil is selected from the group consisting of the mineral oils, polybutene synthetic oils and ester synthetic oils.

10. The process for the production of a thixotropic lubricating compound having a reversible gel structure comprising the steps of:
adding to a reaction vessel a fish oil, a sulfur-modified sperm oil and a microcrystalline wax;
heating the mixture to a temperature of from about 300°F
to about 400°F;
adding to the mixture an oxide of lead; and cooling the mixture.

11. The process of claim 10 comprising the further step of adding a hydrocarbon oil to the mixture in an amount of up to 90%
by weight of the total resulting composition before cooling the lubricating compound and subsequent to adding the oxide of lead thereto.

12. The process of claim 10 comprising the further step of melting the cooled lubricating compound into a hydrocarbon oil wherein the hydrocarbon oil is present in an amount of up to about 90% of the resulting mixture.

13. The lubricating compound of claim 2 which is further mixed with a volatile solvent such as to render it suitable for application as an aerosol spray.

14. The lubricating compound of claim 13 wherein the volatile solvent is selected from the group consisting of the hydrocarbon solv-ents, chlorinated hydrocarbon solvents, and alcohols.

15. A thixotropic lubricating compound having a gel structure reversible after heating beyond the drop point of the compound, non-newtonian flow characteristics, and a broad apparent viscosity range, comprising the re-action product of a crude fish oil, a sulfur-modified sperm oil, a micro-crystalline wax and an amount of an oxide of lead in excess of that amount which would be required to react with the crude fish oil to form a normal lead soap.

16. The lubricating compound of claim 15 further comprising up to about 90% by weight of the total compound of a hydrocarbon oil.

17. The lubricating compound of claim 15 wherein the crude fish oil is selected from the group consisting of crude tuna oil, herring oil, menhaden oil, sardine oil, cod liver oil, halibut oil, salmon oil and shark oil and the sulfur-modified sperm oil is selected from the group consisting of sulfurized sperm oil and sulfonated sperm oil.

18. The lubricating compound of claim 17 wherein the weight ratio of the fish oil to the oxide of lead is from about 1:2 to about 2:1; the weight ratio of the fish oil plus the oxide of lead to the sulfur-modified sperm oil is from about 1:1 to about 4.4:1; and the weight ratio of the micro-crystalline wax to the fish oil plus the oxide of lead is from about 1:2 to about 6.5:1.

19. The lubricating compound of claim 18 wherein the oxide of lead is litharge.

20. The lubricating compound of claim 18 further comprising up to about 90% by weight of the total compound of a hydrocarbon oil.

21. The lubricating compound of claim 18 wherein when the fish oil is crude tuna oil, the ratio of the fish oil to the oxide of lead is about 1,3:1; the weight ratio of the fish oil plus the oxide of lead to the sulfur-modified sperm oil is about 2.3:1; and the weight ratio of the microcrystal-line wax to the fish oil plus litharge is about 1.3:1.

22. The lubricating compound of claim 21 further comprising about 50% by weight of the total compound of an asphaltic residual oil.

23. The lubricating compound of claim 16 wherein the hydrocarbon oil is selected from the group consisting of the mineral oils, polybutene synthetic oils and ester synthetic oils.

24. The lubricating compound of claim 16 which is further mixed with a volatile solvent such as to render it suitable for application as an aerosol spray.

25. The lubricating compound of claim 24 wherein the volatile solvent is selected from the group consisting of the hydrocarbon solvents, chlorinated hydrocarbon solvents and alcohols.

26. The process of claim 10 wherein the oxide of lead is added in an amount in excess of that amount which would be required to react with the fish oil present in the lubricating compound to form a normal lead soap.