US2179060A - Manufacture of lubricating compositions - Google Patents

Description

- imparts extreme Feller-steel 7, 393% st rs emcee Herschel G. Smith, Swavtore, 3%., cssigucr to Gull Gil (Corporation, Piitslaurgls, Fe", o corresection o1? Pennsylvania,

Auglicotiou lsmusry 2.2, 19%

Serial No. some obtained. are compounded with suitable lulori eating oils in suiicieut amount to give a comlubricant having the desired properties, and also comprises the :uuproved suliurized oils and lubricants so obtained, the compounded lubricant being stable in storage and in use and being substantially eon-corrosive tometals; all as more hereinafter set forth and as claimed.

Crisis epullcation is in part c. continuation of my prior coperiding application Serial No. 715,551, riled lvi'arcl'l- 14:, 1934, now United States Patent No. 2,oss,2cv, patented December 22, 1936.

ivlixtures of mineral oil with sulfurmed oils are Well known, such mixtures having been used as cutting oils, Sulfurlzed fatty oils, obtained by adding sulfur to a. fatty oil such es lard oil, etc, and heating the mixture for several hours have been frequently used in making such cutting oils. Likewise, it is Well imown that the addition of suliurized oil to mineral oils pressure characteristics to them. .There is a demand for lubricants which form or films are capable of with standing nigh pressures, such as occur in the gears and transmissions of heavy duty motor trucks and high speed automobiles. Y

.-. ave found that stable non-corrosive lubri= cents having the requisite commercial proper= ties can be obtained by compounding or amounts or" suifurized sperm oil with the usuel mineral lubricating oils. In this way, I obtain superior compounded lubricants. By varying the amount of suliurized sperm oil and the perticular mineral oil used, 2. wide range of commercial lubricants can be obtained.

Although sperm oil is frequently termed e. fatty oil, it is quite difierent from the ordinary fatty oils, vvmch ere tri-esters of glycerine. sperm oil is composed principally of the fatty esters of mono'nydric alcohols of remtlvely' high molecular weight; it being a mono-ester. fictw allysperm oil is a liquid was: of the ester type.

Being an ester, it is also ererlt from the parsfin hydrocarbons commercially mom as waxes.

Sperm oil is obtained from the head cavities and blubber of the cschelot or sperm whale (Physeter macrocephalus). The crude oil contains varying amounts of spermaceti and like solid waxes oi the ester type, 19 Y scod quality is nearly freefrom odor.

(331. Sli -9) oil, these waxes are removedoy refrigeration and pressing, to obtain the commercial sperm oils. The commercial oils are lmown as winter sperm oil, spring sperm oil, etc, and are substauticliy free of solid waxes The commercial 5 sperm oil is a thin yellowllquld and when of In the present invention it is advantageous to use refined sperm oil of good quality. Sperm oil itself is a good lubricant. Being both limpid and substantially free from any teudeeoy to gum (usually resistant to oxidation and resinificetion), it has been long used to lubricate light machinery. Also, it has been blended with mineral oil to form compounded lubricants. I have found that sulfurized sperm oil has enhanced lubricating qualities and has desirable viscosity and blending properties, making it exceedingly useful in compounding lubricents. f Generally, the lubricating compositions of the present invention comprise a major proportion of lubricating oil and a. minor amount of a sulfm'ized sperm oil. Such lubricating compositions sre particularly useful as extreme pres- 5 Gravity, s s. r 13.6-14.6 35

Viscosity, S. 'U. v2, 210 F seconds 2%0-300 Pour: F. (not greater than) Sulfur, per cent 8--l Neutralization number 14.5 40

' Eluliurized sperm oils having the above propertles are readily soluble in all of the ordinary grades of lubricating oils. They are fully miscilile and compatible with the high gravity oils, such as goerafinic base oils (Pennsylvania, etc.) and solvent refined oils, etc., over a wide range of conditions such as temperature, proportions, etc. whee they are compounded with such minoral oils, improved compounded lubricants are obtained which are remarkably stable, as well as having vlscosities, viscosity indexes, specific grevitles, your points, etc. capable, of meeting the technical specifications for high grade com- 3 mercial lubricants. Their lubricating qualities over a Wide range of utilization are excellent.

To produce such high grade sulfurized oils I find it is advantageous to use, as the start-- ing materiel, commercial sperm oil having thev following properties, for example,*but not by way of limitation:

Specific gravity, 60/60 F 0. 878- 884 Viscosity, S. U. V., 100 F 95-110 Flash, 0. C., F., minimum 490 Pour, F., maximum +40 Color, N. P. A., not darker than 1. Neutralization number, maximum 0. 5 Oleic acid eq., per cent., maximum- .0. 25 Saponification number 125-135 I Iodine number 80-90 The sulfur employed should be of good quality and freed any abrasive material such as sand, fossil fragments, etc. Sublimed sulfur, such as flowers of sulfur, is advantageous. However, any finely ground sulfur, such as sulfur flour, may be used.

The amount of sulfur used to sulfurize the sperm oil may be varied according to the particular sperm oil being processed and the specific characteristics desired in the final product. Usually the ratio of sulfur to oil is between 5:95 and 20:80. Generally, I employ substantially an amount of sulfur not exceeding that necessary to saturate the double bonds of the sperm oil used. In controlling the ratio of sulfur to oil, some unsulfurized sperm oil may be present in the final product. This is permissible as unsulfurized sperm oil is more or less a desirable and advantageous ingredient in certain lubricating compositions.

By properly controlling the sulfurizing operation; for instance, by employing the methods given post, the percentage of combined sulfur in the sulfurized sperm oil is approximately that in the reaction mixture. Likewise, very little hydrogen sulfide is formed when the reaction is properly controlled.

In preparing the sulfurized sperm oil, the sperm oil is reacted with suitable amounts of sulfur at temperatures between about BOO-385 R, the reaction being continued until the sulfur is combined in the form of neutral organic sulfur compounds. However, to obtain superior sulfurized sperm oils, I find it advantageous to use reaction temperatures between 335 and 360 F. and to employ controlled methods of sulfurization, wherein decomposition of the oil, side reactions, over-vulcanization, etc., are substantially avoided. If the sulfurization is properly conducted, the viscosity of the oil sharply increases and then the viscosity tends to become substantially constant during the remainder of the heating.

In general, control of the sulfurization is obtained by first preheating the sperm oil to about the lower reaction temperature (325 F.) or slightly below, and then gradually adding the required amount of sulfur to the preheated oil, the rate of addition being adjusted so that heat developed during the addition of the sulfur gradually and quietly raises the reaction mixture to a temperature just below the preferred upper limit (360 F). Advantageously, the finely divided sulfur may be gradually sifted into the oil while agitating. After all the sulfur has been added, the temperature tends to drop slightly and then the reaction mixture is maintained at about 345 F. until the reaction is complete. The course of the reaction may be easily followed by withdrawing test samples and determining the change in viscosity. After the proper viscosity has been obtained, the end point can easily be determined by diluting the sulfurized oil with a standard amount of mineral oil and determining its corrosive action upon a copper strip. When the copper strip remains unattacked or shows only a slight stain, the reaction is complete. Then the sulfurized oil is cooled to about room temperature. It can be stored in metal drums or other suitable containers.

The copper strip test here employed was devised by me in 1917 for determining the relative corrosiveness of lubricating oils, The procedure is as follows:

A mechanically polished copper strip k inch by 3 inches is immersed in 25 cc. of lubricant contained in a test tube which is placed in a boiling water bath and held at the temperature of boiling water for three hours. At the end of this time the strip is removed and adhering oil washed off with a light naphtha and examined for evidence of corrosion. A negative testis one in which the strip shows onlya slight stain or discoloration. The positive test is one where the strip shows considerable discoloration or tendency to scale, indicating presence of corrosive constituents in the lubricant.

In preparing the diluted sample for a test, I ordinarily use a standard mineral oil having the following properties:

Gravity, *A. P. I 27.1 Specific gravity, 60/60 F 0.8922 Viscosity, S. U. V.:

210 F 89 Viscosity index 92 Flash, 0. 0., F 4'70 Fire, 0. C., "F 545 Pour, F -i +5 Color, N. P. A -Q dil 4.25 Carbon residue, percent i 0.44 Neutralization number 0.01

The sample of sulfurized sperm oil is diluted with the above mineral oil in the ratio of :90 to obtain the sample used in determining the corrosion by the copper strip method. The copper strip is removed from the heated oil sample after 3 hours, and then wiped dry and inspected in the usual manner. Sometimes, a test mixture the same as the desired compounded lubricant is used in the above test.

' With the above mentioned controlled methods of sulfurization, there; is but little loss of sulfur; the percentage of combined sulfur in the sulfurized sperm oil is approximately that in the reaction mixture. During the sulfurization, very little hydrogen sulfide .is formed. As the finely divided sulfur is gradually added to the hot oil by sifting, etc., there may be more or less mechanical loss of sulfur. With careful operation, however, this loss may be minimized, if not entirely avoided.

The viscosity 'of the oil increases rather rapidly as the sulfur is added and upon combination of most of the sulfur the viscosity tends to remain substantially constant as the heating is continued. Undesirably low reaction temperatures should be avoided for the best combination of the sulfur and exceedingly high temperature should be avoided to prevent undesirable side reactions. By way of specific example as to the heating, with the sperm oil preheated to between 325-340 F. and the sulfur gradually added so as to bring the reactiontemperature to between 330 and 360 F., the maximum viscosity is obtained with 6 to 11 hours heating; all the sulfur being added during the first two hours. Upon maintaining the tempera ure at 340:5 FL, all the sulfur can be aivaoco:

brought into combtion in the form of neutral sperm oil may be readily and consistently Gil produced by my improved method; the details of ratios of sulfur to oil, or rate of addition of sulfur and of ume of heating being adjusted to the particular materials and equipment used in commercial practice.

From the description ante, the ranges oi temperature generally used are between 325 and. 365 and the time or heating is between 18 and 24; hours, the sulfur added during the first two hours. After the reaction is completed, the oil cooled room temperature and, desired, may be filtered or screened to remove foreign bodies or abrasive materials that have been accidentally introduced into the batch. As the suli'urieed sperm oil is quite visco the filtration may be made while the oil is still not. Sometimes the sulrurlzed oil may be centrifuged, but ordinarily this is unnecessary when care been used to exclude introduction oi foreign matter. However, centrifuging can be advantageously med in later stages of the prowsslng as shown post.

Tie controlled method of sulfurization here employed several advantages. By preheating the oil, it is more or less dried during that the water and other volatiles evaporated. Removal of these volatiles helps to minimize side reactions and the prcduc tion. of corrosive suliur compounds. Further, the more readily dissolves in the hot oil and a uniform n xturo of the reactants is quickly and readily obtained. Stratification or" a heavy layer of molten sulfur and oil, frequently encountered in sulfur-icing iatty oils, can be en-.

tirely avoided by the present methods. The suifur added in finely divded form to the lee-heated ell becomes converted into molten drops which completely dissolve in the oil before they have time to settle to the bottom of the reaction vessel. As the mixing is performed at reaction temperature, combination oi the sulfur with the oil in the desired manner is immediately initiated and thus a. high yield oi. neutral sulfur compounds is obtained. Likewise, the time of reaction is held to a minimum and decomposition of the oil and of the neutral sulfur compounds is avoided. Again, the elevated temperature used throughout the operation renders the sulfurized oil, as termed, more mobile thus facilitating the addition and mixing of the last portions of the sulfur. in accomplishing this result, the heat of reaction is permitted to increase slightly the temeerature oi the reaction mixture in the first stages. at these advantageous resuits may be attributed the gradual addition the in the this controlled niethori there is a worthwhile overall ez'ficiency leading to a high yield of desirable sulfurlseol sperm oil of high purity with a um Rom of materials.

The suliurized sperm oil here obtained when added to mineral oil in or amounts yields improved compounded lubricants. It may be ad vantageously compounded with any of the ordinary mineral lubricating oils to modify the properties thereof. Varying amounts of sulfurized spe oil be pounded lubricant desired and the mineral oil base used. By blending from one-tenth per cent to thirty per cent by weight of sulfurized sperm oil with the various types of lubricating oils and.

greases, I obtain a. wide range of commercial lubricants wherein one or more properties of the lubricant are advantageously improved.- Numerous illustrative embodiments of such commercial blended lubricants, are given post. To

,form such blends or mixtures, various methods may be employed.

In making compound lubricants, the desired amount of sulfurized sperm oil is added to the selected mineral oil and the mixture heated and agitated until a uniform blend is obtained. By using temperatures between 70 and 200 F. for oils, and often higher temperatures for greases for this mixing, the smiurlaed oil quickly blends with the oil or grease. Sometimes the oil or grease may be preheated to such temperatures before adding the sulfurized oil. Again. the sulfurizecl oil while hot, for instance hot oil from the suliurizing operation, may be run into unheated or preheated mineral oil. However, the mixing may be affected at room temperature; it

being sometimes advantageous to dilutefirst themay be blown through the mixture to stir it. The

gas in passing through the oil will remove any volatile compounds that may be dissolved therein. A current of air may be used for this purpose,

but other gases, such as carbon dioxide, nitrogen,-

etc., may be employed. If high temperatures'are used during the mixing and blending, the gas employed should be inert under the given conditions. Generally when the mixture is stirred and agitated by means of a current of air, etc., the desired blending is readily effected at room or. slightly elevated temperature. For-instance, 12 parts of sulfurized sperm. oil and "88 parts of mineral oil may be easily blended by warming the mixture to about 160 F. and blowing a current of air through the warmed oil for about 60 minutes. The air will remove any trace of H23 that might have remained dissolved in the suliurized oil. Blends or compound lubricants using other proportions of sulfurized and mineral oil may likewise be readily obtained by the above methods. The compound lubricant may be filtered or centrifuged, if desired. 4 In this ,way, valuable commercial lubrican useful for lubricating the difierential and transmission units of automobiles may be produced; either a lubricant of Winter or summer grade. The two grades can be easily obtained by simply varying trie mhieral oil. base employed; it being loyeil according to the com.-

oil,;as determined by either the Almen orl'imkeul;

tests for E. P. lubricants. Being stable they can also be med for ordinary lubrication wherein the usual pressures are encountered.

The following examples are illustrative embodiments of the methods and products broadly set forth ante, and are not limitative of the invention.

Example 1.This example illustrates an advantageous method of making the sulfurized sperm oil. A sperm oil having the following properties,

Gravity, "A. P. I 29.0 Specific gravity, 60/60 F 0.8816 Viscosity, S. U. V.:

70 F 1'71 100 F'.. 100 130 F 71 210 F. 43.3 Flash, 0. C., "F 505 Pour, F Color, Saybolt 5 Neutralization number 0.14 Saponification number 130.9 Iodine number 87 I was sulfurized under controlled conditions, using approximately 12 per cent sulfur by weight on the oil;

Intoa direct-fired, ZO-barrel, open-top grease kettle I charged 8057 lbs. of said sperm 'oil (1097 gal.) and gradually heated the oil to 320 F. in,

' about 4 hours, while stirring. While continuing the stirring, l098-lbs. of sulfur flour (approximately 1 lb. of-sulfur per gallon of oil) was gradually added by sifting it into the hot oil over a period of two hours and at such a rate as to maintain a steady increase in temperature to 360.F. Then the temperature was gradually lowered to 340 F. and the reaction mixture maintained at that temperature and stirred for 16 hours; the heating then being stopped and the sulfurized oil cooled to normal temperature. The total time from the first addition of sulfur to the completion of the reaction was about 20 hours.

In the above type operation, after the reaction has been initiated, the fire may be drawn or cut ofi during the addition of the rest of the sulfur, but usually it is only lowered so as to prevent undue loss of heat by radiation. After the reaction mixture is brought to 340 F., the flre is increased to hold that temperature during the remainder of the reaction. The change in viscosity during the reaction was as follows:

lbs. of sulfurized oil; the percentage yield by weight being 99.0 per cent of the materials charged. As part of the loss is due to evaporated water and other volatiles from the sperm oil and sulfur, clearly only a very small amount of His is formed. During the sulfurization a slight odor of hydrogen sulfide was detectable, but the sulfurized oil did not have an objectionable odor. During sulfurization the oil increased in volume and the yield by volume was 1120 gallons. The

- sulfurized oil so obtained was of high quality and had the following properties:

Gravity, A. P. I Specific gravity, 60/60 F 0.9718

Pounds per gallon 8.093 Viscosity, S. U. V., 210 F 242 Pour, F +45 Sulfur (B): per cent 11.10 Neutralization number 0.63 Color, N. P.'A Dark It is readily soluble or dispersible in mineral oil of various grades. When diluted with parts of mineral oil to 10 parts of sulfurized oil, the diluted oil gave only a slight tarnish by the copper strip test.

Example 2.-This example illustrates the manufacture of extreme pressure lubricants from these sulfurized sperm oils and suitable mineral oil bases. A mineral oil (winter grade) was employed, which had the following properties:

To 88 gallons of the above mineral 011, there was added 12 gallons of the sulfurized sperm oil obtained in Example 1. The mixture was warmed to 160 F. and a current of air blown through it, until a uniform blend was obtained. This required about one hour. The product was filtered, but no significant amount of foreign matter was found to be present.

The compound lubricant so obtained is an excellent winter grade E. P. lubricant and has the following properties:

Gravity, "A. P. I Specific gravity, 60l60 F 0.9018 Viscosity, S. U. V.:

F 1144. Ff 469 210 F..-...... 98 Viscosity, furol, 100 F 116 Viscosity index 100 Flash, 0. 0., F 480 Fire, 0. 0., F 555 Pour, "F 0 Color, N. P. A dil.. 5.5 Sulfur, per cent 1.48 Carbon residue, per cent 0.52 Precipitation number Trace Neutralization number 0.08

, Corrosion test, 212 FL, 3 hours Slight tarnish A Steel strips, 212 F., 24 hours:

Dry lubricant- Tarnish Nil Loss, mg 0.2 Wet lubricant (10% water)-- Tarnish Q. Nil Loss, mg 0.1 Ash, per cent 0.002 Centrifuge test: 2 hours room temperature, per cent separated Trace To obtain a summer grade extreme pressure lubricant by the above procedure, in lieu of the continuously for nine months, covering during this period a total of 60,000 miles, the majority of the time under very heavy loads. During this period the lubricant increased in viscosity only 8 seconds at 210 F'., S. U. 1.; while a sulfurized compound lubricant containing one of the usual sulfurized fatty oils was completely solidified in a similar test after 20,000 miles. The solubility of the sulfurized sperm oil was unaiiected by this 10 severe test and the lubricant showed no evidence of stratification or segregation of constituents as shown by the centrifuge test.

The compounded oils utilizing the sulfurized sperm oil as described are particularly useful in a number of relations, as, for instance, marine engine oils, motor oils and in making locomotive driving journal compounds where special greases are needed.

In steam cylinder lubricants where relatively high temperatures and rubbing, speeds prevail,

' my compound has decided advantages over the usual rape seed oil bodied compounds. Such compounds containing rape seed oil and naphthenic or coastal type of lubricating oils can be advantageously improved and made particularly useful for marine engine oils by the addition of a few per cent or a sulfurized sperm oil, say S te I 5 per cent. In such a compound the contained sperm oil increases the oiliness and assists the dispersion of the bodied rape seed oil, whereby the compound retains its lubricating qualities in the upper limits of permissible temperatures and rubbing speeds.

With the present tendency of automobile manufacturers to use special bearing alloys, such as cadmium-silver alloys, cadmi-nichel alloys, copper-lead alloys, and the like, there is a de -r-:= for certain grades of lubricants which will not have corrosive action on them. I have found 4.0 that a small percentage (0.1 to 1.0 per cent) of sulfurized sperm oil in motor oils having high viscosity index, such as Pennsylvania b an and solvent refined oils, will etc the co rosive action on the special type oil alloy w mi to which reference has been made.

In greases used for locomotive vine tournals and the like the melting point must necessarily be rather high, with the result that the wetting power of the lubricating constituent is somewhat limited. The addition of suliuriaed sperm oil to such compound imparts a decided .oiliness" or wetting power, even when as low as 1 to 2 per cent is used'in greases of this type. m types of greases such as those used in automobile wheel bearings, high speed ball bearing and. the like, where the lubricants function under relatively mild bearing loads but high, bearing speeds, from 2 to 10 per cent of sulfurlzed sperm oil can be used to decided advantage.

sulfurized sperm oil is shown in the followinz example:

Example 3.,1'.n preparing a marine engine, oil

I employ the following oil:

Neutralization number...

.A typical good marine engine oil comprising andto'IOpartsofsuchoiLIaddSpartsofsuJ- furized sperm oil and 25 parts of blownrape seed oil.

Example 4.-In preparing a marine engine oil I employ the following coastal lubricating oil dis- 5 tillate of the following properties:

Gravity, P11. P. 1...... 20.7 Viscosity, s. U. v.:

F 1886 210 F s9 10 Flash, 0. 0., "F 470 Fire, 0L0 "F 54:5 P0111, F -5 Color, N. P. A 4.5

Carbon residue, percent 0.3 15

Neutralization number 0.02

and to '70 parts such oil I add 3 parts oi. sulfurized sperm, oil and 27 parts blown rapeseed oil.

The following is illustrative of a typical motor 20 andt0100part80i'thisoi1,1add0.75partby weight of 'sulfurizcd sperm oil.

The following. is an illustration of a locomotive as driving journal compound:

Make-up, percent by weight:

150 dark filtered cylinder stocks 42.9.

' Sodium-stearic acid soap 3.0

Sodiu'rn-tallow oil soap 49.5 40 Sulfurizcd sperm oiL...3 4.6 on of ma -1. 0.00s

Inspection penetration. A. S. T. M., 77 F.,

unworked 06 The following is a typically good steam cylinderlubricant:

e-up, percent by volume: via/210 F. Mid-Continent Bright The following is a typically good grease for automobile wheel bearings, high speed ball bear- 1x188 and the like:

Make-up, perc'entby weight:

300redparamneoil 19.5 65 Sulfurized sperm oil. 4.8-

' Sodium tallow soap.. 13.9

Giycerine 1.4 Water 0.4 Oil of casein. 0.002 70 Inspection:

Melting point, I". Hawxhurst 158 Penetration A. 8. '1'. 15., 77 F., un-

worked 31'? The'addition r W sp'crm'oil mm. as

' bottlenose oil.

of certain esters.

envaoeo wise it .is useful in increasing the oiliness of the,

compounded lubricants. In other words, the suifurized sperm oil in the composition set forth ante has many and diverse efiects and functions, all or which are advantageous.

As stated ante, in lieu of sperm oil itself (oil from the cachelot whale) other oils or the sperm oil group may be used in making the sulfurized products according to this invention. For instance, bottlenose oil (doegling oil) may be employed. It is obtained from several species of toothed cetaceans, particularly the bottlenose whale (Hyperoodo'n rostratum); hence the name It is so like true sperm oil in character, that the commercial'oil is known as. arctic sperm oil. The said class of oils have certain properties in common with true sperm oil; all or" these oils containing characteristic types of fatty esters.

As is well knownetrue sperm oil is a mixture Those esters are the esters of monohydric alcohols with fatty acids of the oleic series, such estershaving the following general wherein R represents an aliphatic chain of relatively high molecular weight; the acid component being likewise of high molecular weight.

From the information available, such as reported analysis, the principal and characteristic components of sperm oil and similar oils of the sperm oil group are mono-esters which are unsaturated or contain double bonds, on each side of the ester group. That is, they are esters of oleic acid or homologous acids of the oleic type with monohydric alcohols of the ethylene series (the series of alcohols corresponding to the oleic series of acids). This characteristic class of monoesters may be represented by the following forwherein n is at least. 1.

Commercial sperm oil contains m nor amounts of other fatty esters but the above mentioned class or" esters are the characteristic components wherein m is 1 to 7, are advantageols for making the said neutral sulfurizeol product. In suliurizing them by the present methods, the added sulfur saturates the double bonds of such esters yielding products having neutrally combined sulfur in each half of the ester. Taking the oleate of oleyl alcohol (oleyl ester oi oleic acid) wherein the a: oi the above formula is 5, as an illustration, the neutral product may he represented by the following formula:

In my copending application Serial No. Gut-57, I have described and claimed the manufacture of improved lubricants wherein suliurized esters of fatty acids are added in minor amount to lubricating compositions, in which the lubricating lease is or contains a major amount of mineral oil. The present application is in part a continuation of the above mentioned application and is directed to an advantageous species of the said generic in vention wherein the suliurized products employed are obtained from sperm oil or the fatty esters characteristic thereof.

While in the foregoing examples I have oe= scribed direct sulfurization oi the sperm oil, 31 times find it advantageous to sulfurize sperm oil in the presence oi another oil, as for instance a petroleum hydrocarbon oil which may well be the same as the oil used for the base tor manuifacturing the compound lubricant. some of the era]. oil is mixed with the sumac prior to the addition of the sulfur.

What I claim is:

1. As an improved compoundluhricant, a u

form blend oil a. major amount of mineral oil lit-- bricating base and a minor amount of suliuriaed sperm oil, said lubricant being stable both in storage and in use and being non-corrosive to metals.

2. As an improved lubricant, a compound lubricant having the following properties:

Gravity, "is. r. I -i sac-ace Viscosity, S. U. V1, 216 F ee-arc Flash, G. ll, ti l, minimum coo Pour, F +5 to +15 Sullur, per cent, minimum lulu said lubricant comprising a mineral lubricating oil and a small amount of a neutral organic sulfur compound dissolved therein, said organic sul i'ur compound being a sulfurizeci sperm oil.

3. The lubricant of claim 2 wherein said suliurized sperm oil is a sulfuriaed sperm oil con:

taining is to 14 per cent sulfur stably combined and having a viscosity at 210 F. of between 225 and 275 seconds.

E H naocm-(cHos-cnr -cHrwmFcm-L-H wherein a is at least 1. Y

5. A method of lubricating bearing surfaces which comprises maintaining between the bearing surfaces, one of which is an alloy selected from the class of cadmium-silver, cadmium-nickel, and copper lead alloys, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein sulfurized sperm oil in a small but sufli cient proportion to retard the corrosion.

6. As a composition of matter, useful as a lubricant, a composition comprising a major proportion of mineral oil and a minor proportion of a stable organic sulfur compound, said organic sulfur compound being a sulfurizednaturally occurring ester of a monohydric alcohol and a high molecular weight fatty acid.

I. An improved lubricant composition comprising a major amount of a mineral oil lubricating base and a minor amount, sumcient to improve the lubricating characteristics of said base under conditions of use, of ,sulfurized sperm Oil.

EERSCHEL G. sm'rn.