US2179063A - Methods of making sulphurized sperm oils and the like - Google Patents

Description

Patented Nov; 7, 1939 UNITED STATES METHODS or MAKING SULPHURIZED SPERM OILS AND THE LIKE Herschel G. Smith, Swarthmore, and Troy Lee Cantrell, Lansdowne, Pa., assignors to Gulf Oil Corporation,- Pittsburgh, Pa., a corporation of Pennsylvania No Drawing. Application September 28, 1936,

Serial No. 103,050

19 Claims.

This invention relates to improved methods of making sulphurized mono-esters of fatty acids and it comprises methods wherein sperm oils and like unsaturated mono-esters are 'quickly sul- 5. phurized under controlled conditions and the sulphurized esters so obtained are refined to remove various deleterious by-products as may be present therein, the sulphurized esters being sometimes admixed with another oil, such as mineral oils, etc., prior to or during or subsequent to such refining; and it also comprises the improved oil compositions so obtained; all as more fully hereinafter set forth and as claimed.

The manufacture of sulphurized sperm oils and like mono-esters and of lubricating oil compositions containing such sulphurized esters are described and claimed in co-pending applications, Serial No. 60,355 and Serial No. 60,357, filed January 22, 1936, by Herschel G, Smith, one of the present applicants. In the methods there described, the sperm oil is controlledly sulphurized to produce simple addition products and to prevent or retard various side reactions by which deleterious by-products are formed, the sulphurization being effected between 300 and 385 F.. withthe main part of the reaction occurring between 335 and 360 F. Within the latter tem perature range no-appreciable amounts of such lay-products are formed. To readily accomplish this, the sperm oil is preheated to about 320 F., and to this preheated oil sulphur is slowly added at such a rate that the temperature of the mixture is gradually andquietly raised to within the said temperature range by the heat of the exothermic reaction. By controlling the temperature and rate of reaction, over-vulcanization and undesirable side reactions are substantially avoided. The sulphurized mono-esters so obtained, being substantially free of undesirable by-products, etc., and containing the sulphur combined in the form of neutral organic sulphur compounds, are excellent improvement agents for mineral lubricating oils and other petroleum products.

As pointed out in the said applications, the undesirable by-products are formed when the reaction with sulphur becomes too vigorous and the of suiphurization described ante is not the only means by which the deleterious effect of by-products in the sulphurized sperm oil may be avoided. The sulphurized sperm oils produced by the present methods are also excellent improvement agents for mineral oils and like purposes. Further, by procedures given post, we obtain sulphurized sperm oils and compositions thereof even superior in color, viscosity, and other properties to the materials directly obtained by the previ-- ous processes for controlled sulphurization of sperm oil.

In addition to yielding superior oil compositions, there are many other advantages in the multi-step process of the present invention wherein the sperm oil is sulphurized and then refined, as set forth post. Certain of these. advantages are inherent in the process procedure itself.

Certain advantageous improvements are now possible in the rapid sulphurizing procedure, the first step of the present method. As the formation of some by-products is now permissible, their being subsequently removed, the time required for combining substantially all of the sulphur and producing the sulphurized sperm oil is shorter. That is, by the present methods the sperm oil is quickly sulphurized in an advantageous manner.

This is accomplished by pre-heatlng the oil and adding the sulphur as fast as it will dissolve in the hot oil; the mixture being positively cooled to dissipate the heat of the reaction and control the temperature. In this way the time required for adding the sulphur and fixedly combining it with the oil in the form of simple sulphur-addition products may be materially shortened.

By these operations, performed at somewhat higher temperatures than in the prior methods described ante, the sulphur dissolves more quickly and the reaction is faster. At the temperatures between 360 and 450 F. here employed and with the oil pre-heated to about 340 F., the time rea liquid wax of the ester type.

quired for producing the sulphurized sperm oil is reduced to a minimum. In the present methods, the heat of the reaction quickly raises the temperature of the sperm oil to the desired reaction temperature, which is held below 400 F, by suitable cooling means. External or internal circulation of a suitable cooling medium may be employed. Either jacketed reaction vessels or those equipped with internal cooling coils may be used in making the sulphurized sperm oil.

Although the temperatures are relatively high, the time required to complete the reaction is sufficiently short to prevent substantial decomposition of the desirable sulphur-addition products, even though the reaction is relatively vigorous.

While the range of temperatures permissible in the present sulphurization methods is more flexible, the temperature is again controlled to prevent any appreciable over-vulcanization. That is, the conversion of the sperm oil into sulphurized products which at room temperatures are semi-solid or solid gelled materials is avoided. Such gelled products are relatively insoluble or immiscible with mineral oils and are not satisfactory for the present purposes. The production of such solid sulphurized oil products represents loss of valuable starting materials, even when the amounts formed are insufficient to render the reaction mixture diificultly miscible with petroleum oil.

Over-vulcanization and decomposition of the valuable sulphurized mono-esters are avoided by holding the reaction temperature below 400 F., as described ante. Thus the reaction is effectively controlled although it is vigorous and rapid.

After the sulphur has combined, the reaction mixture is rapidly cooled below 360F. In this way any undesirable side reactions are checked. This may be accomplished by various cooling means, Advantageously, cooling may be effected by quenching the hot mixture with cool mineral oil. For instance, an equal amount by weight of mineral oil can be mixed with the hot sulphurized sperm oil. The solution of sulphurized monoesters in mineral oil so obtained is readily adapted to the subsequent refining treatments and yields a valuable intermediate product for making a wide range of lubricants. Also, the hot sulphurized sperm oil can be cooled by means of a, suitable cooling medium rapidly circulated in the jacketed reaction vessel or through coils immersed in the reaction mixture. This is also advantageous, as a similar external or internal cooling means may be employed to control the reaction temperature. means for dissipating the heat of reaction is also utilized to cool the sulphurized sperm oil at the end of the reaction.

As pointed out in application Serial No. 60,355, mentioned ante, sperm oil while frequently termed a fatty oil is quite different from the fatty oils which are tri-esters of glycerine. Sperm oil is composed principally of fatty esters of monohydric alcohols of relatively high molecular weight, and, being a mono-ester, sperm oil is Being an ester, it is also different from the parafiin hydrocarbons commercially known as waxes. Sperm oil is obtained from the head cavities and blubber of the cachelot or sperm whale (Physeter macrocephalus). The crude oil contains varying amounts of spermaceti and. like solid waxes of the ester type. In refining the oil these waxes are removed by refrigeration and pressing to For instance, the same obtain commercial sperm oils. The commercial oils are known as winter sperm oil, spring sperm oil, etc., and are substantially free from solid waxes. The commercial sperm oil is a thin, yellow liquid and, when of good quality, is nearly free from odor.

As set forth in application Serial No. 60,357, also mentioned ante, mono-esters of the sperm oil type may be synthetically prepared. By the methods described therein, synthetic sperm oils of controlled color, viscosity, and other desirable properties may be readily prepared. By those methods a wide range of unsaturated mono-esters of fatty acids and mono-hydric alcohols can be obtained, all of which are capable of being sulphurized to produce valuable sulphurized products useful as improvement agents for mineral oils. In the practice of the present invention any mono-esters of those characteristic types may be employed. However, sperm oil ordinarily is here employed. Usually a good grade of commerical sperm oil is used, as they are readily available in quantity and yield good sulphurized materials.

Advantageously we may employ as the starting material commercial sperm oils having the following properties:

Specific gravity, 60/60 F 0.878-0900 Viscosity, S. U. V. at 100 F., seconds -120 Flash, 0. C., F 450-500 Pour, F +35-+65 Color, N. P. A 1.0-3.0, Neutralization number 0-3.0 Oleic acid equiv., percent 0-1.5 Saponification number 120-150 Iodine number 80-100 The sulphur employed should be of good quality and free from any abrasive material such as sand, fossil fragments, etc., and sublimed sulphur such as flowers of sulphur is advantageous. However, and finely ground sulphur, such as sulphur flour may be used.

The amount of sulphur used to sulphurize the above-mentioned mono-esters may be varied according to the particular mono-esters being processed and the specific characteristics desired in the final product. Generally, with the mono-esters as a class capable of sulphurization, the ratio of sulphur to oil may be between 5:95 and 20:80, and good sulphurized esters are obtained, having desirable amounts of sulphur combined therewith in the form of substantially neutral sulphur compounds. Here, the amount of sulphur added to the pre-heated sperm oil is substantially less than that necessaray to completely saturate all of the sperm oil used. In the present sulphurization methods, it is advantageous toadd between 5 to 12 parts of sulphur per parts of the usual commercial sperm oil by weight on the oil. Such amounts of sulphur can be rapidly added to and combined with the sperm oil and the sulphurized sperm oils obtained by the subsequent refining are of special quality. The refined sulphurized esters are thinly mobile and have a light color and other properties rendering them particularlyadvantageous as improvement agents for high grade lubricants, such as highly refined motor oils, etc.

By means of the improved sulphurizing procedures of the present invention, small amounts of sulphur, as indicated ante, give high grade materials, and by the subsequent procedures here employed. Using the relatively small amounts of sulphur in such procedures, the rapid sulphurization is further facilitated. Ordinarily, the sulphurization may be completed within about three hours. As the sulphur almost immediately combines'with the sperm 011' after it goes into solution therein, the sulphurization'is completed shortly after the last portion of sulphur has been added. Sometimes the reaction may be completed within-as short a time as minutes after the sulphur is all added to the reaction mixture,

the time depending" upon the size of the batch,

is added as fast as it will dissolve. As soon as the first of the sulphur has dissolved, the cooling of the reaction mixture is started to prevent such sudden rise in temperature by the heat of the reaction as" will cause the reaction to become unmanageable. As the reaction proceeds the cooling medium is adjusted to maintain the desired temperatures, which are ordinarily held in the neighborhood of 375 F. While vigorous cooling is employed until all the sulphur has been added, after most of the sulphur has been combined less cooling is required to dissipate the heat of the reaction. With proper cooling, the above amounts of sulphur may be added within 30 minutes, and the reaction is substantially complete within 1.5 hours after all the sulphur has been added, At that stage the sulphurized oil, if cooled to room temperature, is thinly mobile, being much less viscous than the prior sulphurizedsperm oil.

To cool the sulphurized oil quickly after the reaction is completed, it is pumped into a sufiicient amount of mineral lubricating oil to lower its temperature below 300 F., the mixture being agitated during this operation. Sometimes the mineral oil is poured into the sulphurized oil while stillin the reaction vessel. Either of these procedures is an advantageous means to quench the hot mixture of 'sulphurized oil and reaction products, The warm solutions so obtained are inter-' perature of the mineral oil so added is generally adjusted to produce oil mixtures having a temperature similar to that employed in the next operation of these processes. By adding an equal weight of mineral oil at ordinary temperature (room temperature) to the hot suiphurized sperm oil, the oil compositions produced are at approximately 200 F. a

The oil composition now being at a temperature of about 200 F. is ready for the acid treatment, that temperature being within the range at which the acid treatment is particularly effective, namely between 150 and 225 F. -To the warm oil composition there is added sufiicient concentrated sulphuric acid, containing '80 to 100 per cent H2804, to efiect the desired acid refining of the oil composition. Ordinarily, 5 to 25 pounds of such acid to a barrel (400 pounds) of oil compo sition is sufllcient. After adding the acid, the

mixture is thoroughly agitated while maintained at the above temperatures, here at about 220 F.

tained In fact,.the temperatures may be advantageously in the upper part of the range specified for acid treatment. By using temperatures between 200 and 225 F., the acid sludge is converted into a hard, solid material which will readily separate from the sour oil composition. In such procedure the hardened acid sludge is separated by filtration rather than by settling;

any residue of hardened sludge remaining in the sour oil being removed by filter pressing after the bulk of the acid sludge has settled out and been removed.

Irrespective of the exact manner in which the acid sludge is formed and removed, the sour oil composition may be readilyrefined by treatment with clay.

In the clay-refining operation the temperature is also controlled to insure complete refining. Advantageously, the temperature employed is between 250 and 275 F. However, the temperature should beheld below 300 F. At higher temperatures discoloration ofthe oil occurs and overheating offsets the improvement in color obtained by this clay treatment.

The sour oil, after separation of the acid sludge, is admixed with a suitable amount of acid-washed clay, such as those commonly used in refining mineral oils and known commercially as Filtrol. The oil-clay mixture is warmed to approximately 275 F. and agitated until the clay has adsorbed the undesirable impurities. Usually from 1 to 30 per cent of such acid-washed clay is sufficient for this purpose. With the sulphurized oils prepared with the amounts of sulphur and acid-treated as described ante, approximatey 20 per cent of clay is ordinarily satisfactory. A further advantage of .employing the higher temperatures in acid-treating the sulphurized sperm oil is that only a slight heating of the sour oil is necessary to increase its tem-'- perature after admixture with the clay; the sour oil being here raised from 220 to 275 F.

In the clay treatment agitation at the said temperatures for about three hours is usually sufiicient to adsorb the undesirable impurities present in such sour oil compositions, After the impurities have been fixedly adsorbed by the clay, the agitation is discontinued and the refined oil separated and recovered. Advantageously, this is accomplished by filter pressing the hot mixture. Also, the clay may be settled out of the refined oil composition.

Sometimes the acid treatment may be omitted, if an extremely light color is not required. That is, a clay treatment alone may be used to remove the deleterious impurities and improve the color and other properties of these oil compositions. Usually, in such instances, a single treatment wit .clay is employed. However, by using longer trea ment with large amounts of clay or by repeated treatment with clay, products having a color and other properties approaching that secured by the combination of acid and clay treatment sometimes can be obtained When the refining is by clay treatment alone, the procedure given ante is slightly modified. In such instances, the cooling of the sulphurized sperm oil is so adjusted as to obtain an oil composition having a temperature of approximately 2'75 F. This being an advantageous tempera ture for clay treating, the clay may be directly added to the so-cooled oil composition. Further, if desired, the clay treatment can be elfected in the same reaction vessel. In such advantageous procedures, the sperm oil is sulfurized' as before and, upon completion of the sulfurization,

the circulation of the cooling medium is discon-- tinued. While continuing the agitation sumcient mineral oil is added to cool the mixture to the said temperature, say approximately in a ratio of 1:3 parts of mineral oil to sulphurized oil. The exact ratio depends upon several factors, such as the specific heats of the oils, natural radiation, and whether a pre-cooled mineral oil or one at ordinary temperature is added.

There is added approximately 30 per cent of the acid-washed clay by weight on the sulphurized sperm oil content of the so-diluted oil as soon as the sulphurized oil composition has been cooled to the desired temperature. During this time the agitation is continuous, but now a suitable heating medium, such as steam, is circulated in lieu of the previous cooling medium. The heating and agitation are continued until the clay fixedly adsorbs the undesirable impurities, about three hours being required. Then the mixture, while still hot, is filter pressed to remove the so-separated impurities and excess clay. On filtering the hot mixture the refined sulphurized sperm oil is readily separated from the suspended solid materials, it being extremely thin and mobile. In this operation the mixture is ordinarily pumped through the. filter presses under substantial pressure. Thus the separation is rapid and smaller amounts of the hot oil composition remain adsorbed in the filtered clay. The filter cake may be extracted with a light parafiinic naphtha which dissolves the oil composition without disturbing the adsorbed impurities. As pointed out ante, parafiinic hydrocarbons have a precipitating action upon such undesirable impurities of these compositions.

The oil composition so recovered may be separately collected or it may be recycled and used indiluting another batch of reaction mixture containing sulphurized sperm oil. In fact, recycling may be employed to advantage in certain modifications oi the present processes. For instance, the desirable oil constituents in the separated clays obtained during refining may be completely extracted by suitable means and the extract given an acid treatment to remove any impurities also extracted in such complete treatment of the spent clay. The sour oils from the acid treatment being introduced with the cold diluted oil in a subsequent clay treating operation, an acid refining may sometimes be used as a collateral operation to the main refining proccdures and a part of the desirable products recycled in this manner. By using a rather light highly parafiinic mineral oil for such treatment of spent clay, this light oil solution may be employed as a diluent for cooling the reaction mixture of sulphurized materials. In any of these ways, the loss" of valuable sulphurized sperm oil in either the acid sludge or spent clay may be reduced to a minimum.

Thus, various diluents may be employed in the present process and their amounts varied according to the exact combination of steps employed.

In fact, sometimes it is advantageous to omit the use of diluents entirely and directly refine the sulphurized sperm oils. In such instances, a combination acid and clay treatment is ordinarily used. In that modification of the present invention, the circulated cooling medium is lowered in temperature or is circulated more rapidly, after the sulphurization is complete, to bring the temperature to that desirable for the acid refining.

'With undiluted sulphurized esters the higher Gravity, A. P. I 29.0 Specific gravity, /60 F 0.8816 Viscosity, S. U. V., seconds:

F 1'11 F I 100 F '71 210 F 43.3 Flash, 0 C., F 505 Pour point, F 35 Color, Saybolt -5 Neutralization number 0.14 Saponification number 130.9 Iodine number 87 By the following procedure such oil is sulphurized under controlled conditions, using approximately 12 per cent sulphur by weight on the oil.

Into a direct-fired, open-top grease kettle, equipped with suitable cooling coils, we charge 8057 pounds of said sperm oil (1097 gal). The oil is gradually heated to 340 F. in about 2 hours, while stirring. While continuing the stirring, 1098 pounds of sulphur flour (approximately 1 lb. of sulphur per gallon of oil) is rapidly added to the pre-heated oil over a period of 30 minutes. As soon as the reaction becomes vigorous, the heat ng is discontinued. The heat of reaction quickly raises the temperature to between 360 and 385 R, where it is maintained for one hour by sufiicient cooling. After the sulphur has combined, the mixture'is cooled to 275 F. for further treatment with clay, as shown in Example 2.

After all the sulphur dissolves, the viscosity changes as follows:

"isrnsity, S. U. V. at 210 F., seconds Minutes In this way there is obtained 8955 pounds of sulphurized oil; the percentage yield by weight being approximately 98 per cent of the materials charged.

The sulphurized oils so obtained are of high quality and have the following properties:

Gravity, A. P. I 16.4 Specific gravity, 60/60 F 0.9567 Pounds per gallon 7.967 Pour, "F +60 Sulphur, 3., per cent 9.28 Viscosity, S. U. V. at 210 F., sec 135 10 Color, N. P. A (dilute) 8.5 Neutralization number 0.58

Example 2.--The-following example illustrates an advantageous embodiment of the clay refining procedure as applied to an undiluted, partially 15 cooled sulphurized sperm oil such as that obtained in Example 1.

While continuing the agitation of the partially cooled sulphurized sperm oil there is added 1791 poundsof commercial acid-treated clay having 20 fineness between 200 and 300 mesh. The mixture is maintained at 275 F. for approximately three hours. At the end of that time substantially all of the deleterious impurities are adsorbed by the clay. The mixture is then pumped to a suitable filter press and the hot refined sulphurized oil is separated from the excess clay and adsorbed impurities.

In the following table the properties of the sulphurized sperm oil before and after refining 30 are given, together with the properties of a prior type of sulphurized sperm oil such as disclosed In the above example, the filter cake may be treated by suitable means to recover the residual sulphurized sperm oil absorbed therein. Ad-

and stirred into a relatively large volume of highly parafilnic mineral oil having the following properties:

W Gravity, A. P. I 33.1 Specific gravity. 60/60 F 0.8597 Viscosity, S. U. V., seconds:

60 210 F v 46 Viscosity index 108 V-G constant .800 Flash, 0. C., "F 420 Fire, 0. C., F 490 65 Pour, "F 0 Color, N. ,P. A 1.25 Sulphur, per cent by weight .05 Carbon residue .02 Copper strip test Passes solution of recovered sulphurized sperm oil is siphoned off from the settled solids. This mineral oil solution may be advantageously employed 75 as a diluent in quenching the hot sulphurized vantageously, the filter cake may be broken up After thoroughly agitating, the so-washed clay is permitted to settle. Then the mineral oil reaction mixture obtained in the sulphurizing procedures. When so recycled, it is ordinarily employed as a diluent to prepare intermediate compositions for acid refining.

Example 3.'This example illustrates those modifications of the present invention wherein.

the sulphurized sperm oil is quenched by dilution with a mineral oil and the intermediate product so obtained is acid-treated prior to the clay treatment. The following procedure is typical of the acid-refining procedures. The sulphurized sperm oil here refined is prepared by the procedure of Example 1, wherein the hot sulphurized mixture is quenched and cooled to 150 F. by adding to 1000 pounds of the hot oil 1000 pounds of pre-cooled paraflinic mineral lubricating oil, the mineral oil being sufiiciently cooled to give the desired temperature when the oils are admixed. The parafiinic mineral oil employed has the following properties:

Gravity, A. P. I 33.1 Specific gravity, 60/60 F 0.8597 Viscosity, S. U. V., seconds:

210 F 46 Viscosity index. 108 V-G constant 0.800 Flash, 0. C., F 420 Fire, 0. C., F 490 Pour, "F 0 Color, N. P. A 1.25 Sulphur, percent by weight 0.05 Carbon residue 0.02

Copper strip test Passes In lieu of that mineral oil, the solution of recovered sulphurized sperm oil obtained by washing the clay as set forth in Example 2 may be employed as the diluent.

To the intermediate oil mixture so obtained,

While maintained at 150 F., there is added 50 pounds of 98 per cent sulphuric acid, ordinary commercial grade. This is approximately pounds of acid per barrel of oil composition. The mixture is thoroughly stirred until uniform and then the mixture is heated to between 180 and 200 F., while continuing the agitation for approximately one hour. The agitation is then discontinued and the acid sludge permitted to settle out. The Stratified acid sludge is usually withdrawn and so removed represents approximately 10 per cent of the oil composition being refined. The sour oil so obtained may be readily refined with clay.

Example 4.- The sour oil so obtained in Example 3 is clay refined by-the procedure given in Example 2. Being a dilute sulphurized sperm oil, a suitable adjustment is made in the amount of acid-washed clay employed. Here, too, an excess of clay is employed; the clay also neutralizes the sour oil. To insure neutralization of such acid oil compositions, small amounts of lime are sometimes added. Approximately per cent by weight of acid-washed clay on the oil composition satisfactorily refines the intermediate oil composition obtained in Example 3. If the dil-' uent there employed is the mineral oil solution of recovered sulphurized .sperm oil, a,somewhat larger amount of clay maybe employed, say per cent. With the larger amount of clay a very thorough refining is obtained and the refined intermediate oil composition obtained has a very light color, being usually about 3 N, P. A.

The following table gives the properties of the efined intermediate oil composition obtained by the combined acid and clay treatment of Examples 3 and 4; the same properties of the blended intermediate before acid refining and of the original sulphurized mixture are also given for purposes of comparison.

Blended Refined Sulplaurineringer iz v me iatc me iate Propemes mixture before acid and original acid clay refining refined Gravity,A .P.I "n.7,... 16.4 24.4 25.3 Specific gravity, 60l60 F. 0. 9576 0. 9076 O. 9024 Pounds per gallon 7.907 7. 558 7. 514 Viscosity, S. U. V. at 210 F.,

seconds 135 71. 1 67. 9 Pour, F +60 +45 +45 Color. N. P A 8 5 (dil.) 4 75 (diL) 3. 5 Sulfur, percent 9. 28 5. 06 4. 67 Neutralization number 0. 58 0. 2G 0. 5

The above refined solution of sulphurized oil in parafilnic motor oil is an excellent intermediate for preparing a wide range of commercial lubricants. A typical illustration of its use in making lubricating compositions is given post.

The combination acid and clay refining procedures may be employed also with advantage to sulphurized sperm oils prepared by Example 1,

which have been diluted with mineral oils derived from a naphthenic base oil. When naphthenic lubricating oils derived from such a base by solvent extraction are employed, the preliminary acid treatment is'further advantageous, particularly when effected at the higher temperatures. In this way intermediates are obtained which, when further. diluted with more lubricating oil, particularly a similar solvent-extracted lubricating oil, produces motor oils and other lubricants having improved resistance to sludging.

The following example. illustrates the use of the refined intermediate oil compositions containing the substantially pure sulphurized sperm oil dissolved in a mineral oil.

Example 5.-This example illustrates the preparation of an improved motor oil useful for lubricating alloy bearings, etc.

This improved motor oil is prepared by dissolving l.8 per cent by weight of the refined intermediate oil composition of Example 4, in a paraflinic lubricating oil having the same properties as that employed in Example 3 to quench the hot sulphurized sperm oil. The paraflinic motor oil here employed is a S. A. E. 10 grade oil.

The motor oil produced from the refined intermediate contains 0.9 per cent of substantially pure sulphurized sperm oil. It is stable to light, has a very light color, and possesses an extremely high resistance to sludging,

This motor oil has extreme pressure characteristics. When tested by the Almen Test the following results were obtained:

The excellent character of this improved motor oil for lubricating special 'alloy bearings is clearly shown by the results obtained with the accelerated corrosion test ordinarily used to determine the suitability of lubricants for such alloys.

Mineral Special oxidation and corrosion test lubrgcizlating Time oxidized, hours l 48 48 Oil bath temperature, "F 347 347 Air rate, cubic centimeters per he 2, 000 2,000 Oil volume. cubic centimeters". 300 300 Oxidized oil:

Gravity, A. P I 31.1 32. 3 Viscosity, S. U. V., seconds:

F 212 200 210 F 48 47 Viscosity index .r 107 103 Carbon residue, percent 0.39 0. 2G Neutralization number 1. 34 0. 40 Sludge, percent 0.01 0. 30 Cadmium-silver bearing:

Weight before test, g 37. 1578 36. 3571 Weight after test, g 36. 7515 36. 3501 Change in weight, g. 0. 4013 +0. 0021 Weight loss, percent. 1.08 i\ 1!. Appearance Etched Good The improved intermediates produced by the present methods are useful in making other lubricating oils and lubricants having extreme pressure characteristics. My blending the refined intermediate with sufldcient additional mineral lubricating oil, either those derived from paraffinic or naphthenic stocks to give compositions containing between2 and 10 per cent of the rapidly sulphurized sperm oil, there are obtained lubricating oils having excellent properties and general utility for lubricating metals wherein the lubricant is subjected to high pressure, that is relatively high bearing loads. The so improved motor oils are useful in the various engines equipped with ordinary bearings, also.

In fact, these improved intermediates may be blended with other ingredients, in addition to the mineral oils, to produce a wide range of improved lubricants. By employing other suitable ingredients, greases, marine engine oils, locomotive driving journal compounds, steam cylinder lubricants, etc., may be readily prepared. That is, the intermediate oil compositions obtained by the present improved methods may be employed in preparing any of the particular lubricating compositions set forth in the said co-p'ending application, Serial No. 60,355.

Moreover, the present improved methods, as stated ante, are highly advantageous in preparing lubricants for special alloy bearings. Those compositions prepared by the present methods from' paraflinic base lubricating oils, such as il-' lustrated in Example 5, are very stable in storage even when exposed to the action of light for long periods. Under such conditions there is no separation or insoluble matter. The oil compositions prepared entirely from lubricating oils derived from naphthenic base stocks show a marked improvement as to their sludging characteristics. That is, motor oils prepared by the present methods wherein a lubricating oil obtained by solvent extraction of naphthenic stocks is employed,

10 both in diluting the hot sulphurized mono-esters and in the blending operations, are very advantageous in lubricating special alloy bearings in modern automobile engines. They are particularly stable in storage and have a relatively long 5 life in the engine. Further, they have a marked resistance to sludging. Thus the lubricant requires less frequent change or replenishment in such engines when this type of improved motor oil is employed.

Also, by the present method blended oils may be readily and advantageously prepared. For instance,.a refined intermediate comprising a sulphurized sperm oil dissolved in a lubricating oil derived from napththenic stock, and refined by a combined acid and clay treatment, may be advantageously further diluted and blended with a paraflinic lubricating oil. The intermediate having been thoroughly refined, the parafiinic oil may now be incorporated without giving rise to any tendency towards separation of in solubles when the oil composition is exposed to light for long periods. On the other hand, an intermediate oil composition comprising the sulphurized oil dissolved in paraflinic lubricating oil, and obtained by clay refining alone, may be advantageously diluted and blended with the naphthenic type lubricating oils. In either of the above types of motor oils or lubricants containing blended mineral oil bases, the lubricating oil derived from a parafiinic base or from a naphthenic base may be present as a major component of the lubricant.

The improved intermediates produced by the present methods are useful in making other lubrieating oils and lubricants having extreme pressure characteristics. By blending the refined intermediate with sufficient additional mineral lubricating oil, eithers, those derived from parafllnic or naphthenic stocks to given compositions containing between 2 and 10 per cent of the rapidly sulphurized sperm oil, there are obtained lubricating oils'having excellent properties and general utility for lubricating metals wherein the lubricant is subjected to high pressure, that is, relatively high bearing loads. The so improved motor oils are useful in the various engines equipped with ordinary bearings, also.

In fact, these improved intermediates may be blended with other ingredients, in addition to the mineral oils, to produce a'wide range of improved lubricants. By employing suitable other ingredients, greases, marine engine oils, locomotive driving journal compounds, steam cylinder lubricants, etc., may be readily prepared. That is, the intermediate oil compositions obtained by the present methods may be employed in preparing any of the particular lubricating compositions set forth in the said co-pending'applica- 7 ticn Serial No. 60,355.

' However, the present improved methods, as

stated ante, are highly advantageous in preparing lubricants for special alloy bearings. Those com- 1 positions which are prepared by the present methods from parafllnic base lubricating oils,

such as illustrated in Example 5, are verystable in storage, even when exposed to the action of light for long-periods. 'Under such-conditions there is no separation of insoluble matter. Theoil compositions prepared entirely from lubricating oils derived from napththenic base stocks show improvement as to their slu dging characteristics. That is, motor oils prepared by the present methods, wherein a lubricating oil obtained by solvent extraction of naphthenic stocks is employed in diluting the hot sulphurized monoesters and in the blending operations, arevery Also, by the present method, blended oils may be readily and advantageously prepared. For instance, a refined intermediate comprising a sulphurized sperm oil dissolved in a lubricating oil derived from naphthenic stock, and refined by a combined acid and clay treatment, may be- I advantageously further diluted and blended with a paraflinic lubricating oil. The intermediate having been thoroughly refined, the parafilnicoil may now be incorporated without giving rise to any tendency towards separation of insolubles when the composition is exposed to light for long periods. On the other hand, an intermediate oil composition comprising the sulphurized oil dissolved in paraflinic lubricating oil, and obtained by clay refining alone, may be advantageously diluted and blended with the naphthenic type lubricating oils. In either of the above types of motor oils or lubricants containing blend-. ed mineral oil bases, the lubricating oil derived from a parafiinic base or from a naphthenic base may be present as a major component of the lubricant.

The following example illustrates another advantageous method of making improved sulphurized sperm oil comopsitions by the present invention.

hot sulphurized sperm oil. By so quenching the hot sulphurized sperm oil, an oil composition is obtained (an intermediate for refining) which is at approximately the temperature desired for acid treatment. The sulphurizing vessel is flushed with mineral oil, using an amount about equal in weight to the sulphurized sperm oil, and then the washings are combined with the main body of oil composition, the composition so obtained being then adjusted to approximately 20 per cent of sulphurized oil and having a temperature of about F. .In so quenchingand diluting the sulphurized sperm oil, there is employed a lubrieating oil obtained by solvent-extracting a mixed base stock.

This solvent-extracted oil has the following properties:

Gravity, A. P. I 27.8 Viscosity, S. U. V., seconds:

100 F 345 130 F 160 210 F 54.1 Flash, 0. C., F 425 Fire, 0.0., "F 495 Color,N. P. A 3.0

After this solution is brought to approximately 150 F., there is added 5 pounds of 80 per cent sulphuric acid per 100 pounds of oil composition.

The mixture is agitated and gradually brought to between 200 and 225 F., and maintained at such temperatures for about one hour. The agitation is stopped and the temperature held at about 225 F. until the acid sludge is hardened and most of it settles out of the oil composition. The stratified oil composition (sour oil) is drawn ofi and is filter pressed while still hot.

The hot filtrate is then mixed with 10 pounds of acid-washed clay per 100 pounds of sour oil.

The mixture is agitated and heated to approximately 275 F.-, being .held at that temperature for three hours. The hot mixture is then filter pressed. The filtrate so obtained is a valuable intermediate oil composition. It is a refined material substantially free from the impurities deleterious in lubricating compositions. The refined intermediate so obtained may be converted into valuable motor oils for special alloy bearings. To prepare such improved motor oil, the refined intermediate is dissolved in sufficient of the same lubricating oil (solvent-extracted oil) employed ante to' produce a finished solution containing approximately 0L8 per cent of refined sulphurized sperm oil. This improved motor oil has improved loresistance to deterioration, in addition to lubricating alloy bearings without substantial corrosion of the same. That is, the improved motor oil has a relatively long life in lubricating engines equipped with such bearings.

The above refined intermediate may also be converted into improved motor oils by dissolving it in other lubricating oils. A difierent lubricating oil derived from a naphthenic base or mixed base stock may be employed so that the mineral oil component of the finished lubricant is a. blended mixture of two or more lubricating oils, In this way, the final lubricant may contain oils of difierent S A E classification, for instance S A E 30 and S A E 40. Thus by the present invention, a fine adjustment of the properties of the finished lubricant can be readily obtained for the conversion of the intermediate oil composition intothe finished lubricant. In fact, parafiinic motor oils may be likewise employed to dissolve the above refined intermediate and a further adjustment in the characteristics of the finished lubricant obtained. The highly parafiinic motor oil mentioned in Example 2 is advantageous for this purpose.

,(23 In most of the above procedures, the major constituent of the final lubricant is incorporated after the refining has been completed. Thus the selection of the mineral oil employed to dissolve the refined sulphurized sperm oil or the refined intermediate oil compositions should be carefully selected. The mineral oil being the major constituentof the final lubricant, its properties more or less impart the dominating characteristics of the finished lubricant. However, it is primarily the improved sulphurized sperm oil or refined intermediate oil composition which produces the improvements here obtained. In other words, the mineral lubricating oils employed in the methods of the present invention are improved by the refined sulphurized oil compositions incorporated in the same.

What we claim is:

1. In an improved method of making sulphurized oil compositions from mono-esters of fatty acids, the improvements which comprises sulphurizing the fatty mono-ester at temperatures between 360 and 450 F. to produce sulphurized esters containing minor amounts of by-products deleterious in lubricating composition and subsequently removing the said by-products by mixing the sulphurized esters with an acid washed clay, agitating the mixture until said clay absorbs the products deleterious in lubricating compositions and recovering the refined sulphurized esters from said mixture.

2. The process of claim 1 wherein the fatty mono-ester is sperm oil.

3. The proces of claim 1 wherein the sulphurization is efiectedbetween 360 and 400 F., and the sulphurized esters are quickly cooled to below 300 F. to check the side reactions.

4. The process of claim 1 wherein the monoester is pre-heated to about 340.F., finely divided 'sulphur is added as rapidly as it dissolves, the

heat of reaction being dissipated by positive cooling to maintain the reaction mixture below 400 F.

5. The process of claim 1 wherein the sulphurized mono-esters are diluted with mineral oil prior to said treatment with acid lined clay.

- 6. The process of claim 1-wherein the sulphurization is effected between 360and 385 F., and the hot sulphurized mono-esters are quickly cooled by adding suflicient mineral oil to lower the temperature below 300 F.

7. The process of claim 1 wherein an excess of acid washed clay is added to the said sulphurized esters and the added clay and absorbed impurities are separated from the so-refined sulphurized mono-esters by filter pressing.

8. The process of claim 1 wherein the removal of the said deleterious by-products is efiected by a combined acid and clay treatment, the sulphurized mono-ester being given an acid treatment to separate an acid sludge prior to said treatment with clay.

9. The process of claim 1 wherein the refined sulphurized mono-esters are subsequently dissolved in sufilcient mineral lubricating oil to obtain improved lubricants.

10. In the manufacture of improved oil compositions from sperm oil, the steps which comprise pre-heating the sperm oil to approximately 340 F., rapidly adding finely divided sulphur to the pre-heated oil as fast as the sulphur dissolves therein, efiecting the sulphurization at temperatures between 360 and 400 F., the reaction mixture being cooled to maintain the temperature below 400 F., and quickly cooling the sulphurized sperm oil to below 300 F. after substantially all of the sulphur has combined, and subsequently admixing the sulphurized sperm oil with an acidwashed clay, agitating the mixture until said clay adsorbs the by-products deleterious in lubricating compositions, and recovering the refined sulphurized sperm oil from said mixture.

11. The process of claim 10 wherein the hot sulphurized sperm oil is diluted with mineral oil to quickly cool the mixture to below 300 F., and wherein the hot oil composition is admixed with clay, the mixture agitated at temperatures between 250 and 275 F. until the said by-products are adsorbed and then separating thereflned oil composition from the excess clay and adsorbedmaterial by filtration.

12. The process of claim IO-Wherein the hot sulphurized sperm oil is quickly cooled to between 150 and 225 F., the so-cooled composition is admixed with acid and maintained at said temperatures until acid-removable impurities are separated, and removing-the acid sludge from the sorefined oil composition, the sour oil composition so obtained being subsequently refined with clay.

13. The process of claim 10 wherein the hot sulphurized sperm oil is quenched with a mineraloil from a naphthenic oil base and the refined oil composition so obtained is subsequently diluted with a parafiinic mineral oil to obtain an improved lubricant having a mixed mineral oil base.

14. The process of claim 10 wherein the hot sulphurized sperm oil is quenched with a mineral oil from a parafiinic oil base and the refined oil composition so obtained is subsequently diluted with a naphthenic mineral oil to obtain an improved lubricant having a mixed mineral oil base.

15. The process of claim 10 wherein the refined sulphurized sperm oil so obtained is subsequently dissolved in a mineral lubricating oil to produce improved lubricants stable to light and resistant to sludging.

' 16. In the manufacture of improved sulphurized sperm oils, the step which comprises rapidly sulphurizing sperm oil at a temperature between 360 and 400 F., mixing the sulphurized sperm oil with sulphuric acid, heating the mixture besperm oil with a clay capable of adsorbing the impurities deleterious in lubricating compositions agitating the mixture at temperatures between 250 and 275 F., and recovering the refined sulphurized sperm oil.

- 18. In an improved method of making sulphu rized oil compositions, the process which comprises rapidly sulphurizing sperm oil at a temperature between 360 and 400 F., acid refining thesulphurized sperm oil, clay treating the sour oil so obtained, recovering the so refined oil, and dissolving the refined oil in a mineral oil to obtain improved lubricants.

19. The process of claim 18 wherein the sulphurized sperm oil is diluted with a mineral oil prior to acid refining. v

HERSCHEL G. SIWIITH. TROY LEE CANTRELL.

CERTIFICATE OF CORRECTION.

Patent No. 2,179,065. I November 7, '1959.

HERSCHEL G. SMITH, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second 'column, line b2, for. "and" read any; page 7, first column, line 50, for the words "in solubles" read 1118011113188; line 1L9, for "given" read give; page 8, second column, line 25, claim 5, for "process" read process; line 35, claim 5, for the word "lined" read washed; and that,the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 12th day of December, A. D. 1939 Henry Van Arsdale. (S eal) Acting Commissioner'of Patents.