US2179066A - Manufacture of sulphurized sperm oil - Google Patents

Description

Patented Nov. 7, 1939 UNITED STATES PATENT OFFICE 2,179,066 MANUFACTURE OF SULPHURIZED SPERM Herschel G. Smith, Wallingford, Pa., assignor to Gulf Oil Corporation, poration of Pennsylvama Application October 29, 1936, Serial No. 108,306

N Drawing.

esters of fatty acids are sulphurized and substan .tially' neutral organic compounds are obtained, the sulphurization being gradually effected, advantageously by gradually adding sulphur to preheated sperm oil and maintaining the mixture between 300 and 335 F. untilsubstantially all the sulphur has combined, and it also comprises the substantially neutralsulphurized sperm oils so obtained, said sulphurized oils being soluble in and miscible with petroleum oils and like hydrocarbons and useful as improvement agents for petroleum products and being capable ofimparting extreme pressure characteristics to mineral lubricating oils and other lubricants and of improving the other properties ofsuch petroleum products; all as more fully hereinafter set forth and as claimed.

In my copending application Serial No. 60,355,

filed January 22, '1936, I have described and" claimedimproved lubricants containing sulphurized sperm oils and like sulphurized esters and methods of ma g such lubricants, which an )licationis a continuation-in-part of my applical ion Serial No. 715,551, filed March 14, 1934, now U. S. Patent No. 2,056,247. The present application is continuation-impart of my said prior applicaons.

rized sperm oilsand to methods of making'the same wherein sulphur is reacted and chemically 4 combined with sperm oil and like imsaturated ali- 5 phatic mono-esters of an unsaturated aliphatic mo'novalentacid and air-unsaturated aliphatic monovalent alcohol, to produce substantially neutral] organic sulphides readily soluble in iiiineral o. 40 The sulphurization of fatty oils is well known, the usual practice being to mixrelatively large amounts of sulphur with the fatty oil and heat the mixture until a sulphurized fatty oil is obtained. Such sulphurized fattyoils have been used for many purposes in the industrial arts. For instance; sulphurized fatty oils, obtained by adding sulphur to a fatty oil such aslard oil, etc. and heating the mixture for several hours, have been frequently used'in making the so-called cut- 5o ting oils. Such cutting oils are primarily-mix- The present invention is directed to the sulphuoils, which are tri-esters of glycerine. is composed principally of the fatty oil is a liquid wax of the ester type.

Pittsburgh, Pa., a. cortures of mineral Oil with sulphurized fatty oils.

.These oils and other mixtures of mineral oil'and sulphurized fatty oilare well known in various arts.

Likewise, it is well known that the addition of 5 sulphurized oil to mineral oils, imparts extreme pressure characteristics to them. There being a demand for lubricants which in the form of thin films are capable of withstanding high pressures, such as occur in the gear and transmission com- 10 binatlon of modern automobiles and other machines, it has been proposed to use mixtures of mineral oil and sulphurized fatty oil for lubricating such machines. However, it has been found that the usual mixtures are not sufliciently stable in storage or in use or both and that they are more corrosive than is permissible.

The ordinaryfatty oils or esters heretofore employed for said purposes are glycerides; they be-' ing tri-esters of glycerine in which the glycerine is esterified with' three mols of fatty acid. I have found that it is somewhat difiicult to control the sulphurization of such tri-esters and that many of the sulphurized products obtained from them are not suitable for blending with lubricating compositionsfor several reasons. For one thing, they frequently lack sufiicient solubility for blending with many of the usual lubricating bases. Again, when sufliciently soluble to permit blending with mineral oil under some conditions, they are insufficiently miscible over a range of conditions to permit the production of good stable compounded lubricants. Further, many of the mix-' tures of sulphurized tri-esters of fatty acids and mineral oils are often corrosive to various metals 3 and alloys such as used in gears and bearings, particularly certain alloys such as binary and ternary alloys of silver, cadmium, nickel, copper and lead.

In many cases this oorrosiveness, while not appar: 'ent in the freshly prepared compounded lubricant, I 40 develops during storage or in use.

Although sperm oil is frequently termed a fatty oil, it is quite different from the ordinary fatty Sperm oil esters of 45 monohydric alcohols of relatively high molecular weight; it being a mono-ester. Actually sperm Being an ester, it is also different from the parafhn hydrocarbons commercially known as waxes.

sperm oil, etc., and are substantially free of solid- 1 waxes. The commercial sperm oil is a thin yellow liquid and when of good quality is nearly free from odor. In the present invention it is advantageous to use refined sperm oil of good quality.

Sperm oil itself is a good lubricant. Being both 5 limpid and substantially free from any tendency to gum (usually resistant to oxidation and resinification), it has been long used to lubricate light machinery. Also, it has been blended with mineral oil to form compounded lubricants.

I 20 I have found that by controlledly sulphurizing sperm oil, its lubricating qualities are enhanced. The sulphurized sperm oils so prepared, have desirable viscosities and blending properties which render them exceedingly useful in compounding 25 lubricants. They may be compounded with lubricating mineral oils and various other lubricating compositions according to the procedures set forth in my companion application Serial No. 60,355 to obtain improved lubricants.

30 By the present invention there are readily obtained sulphurized sperm oils and like esters for many industrial purposes. Excellent sulphurized ,esters advantageous as improvement agents for lubricants may be readily prepared, for instance,

35 the advantageous sulphurized sperm oils having the following properties:

Gravity, A. P. I 13.6-51.6 Viscosity, S. U. V., 210 F., seconds 200-300 Pour, "F. (not greater than) +45 4 Sulphur, per cent 844 Neutralization number 1-1.5

sulphurized sperm oils having the above properties are readily soluble in all of the ordinary 45 grades of lubricating oils. They are fully miscible and compatible with the high gravity mineral oils, such as paraflinic base oils (Pennsylvania, etc.) and solvent refined oils, etc., over a wide range of conditions such as temperature, proportions, etc.

50 When they are compounded with such mineral oils, improved compounded lubricants are obtained which are remarkably stable, as well as having viscosities, viscosity indexes, specific gravities, pour points, etc., capable of meeting the 55 technical specifications for high grade commercial lubricants. Their lubricating qualities over a wide range of utilization are excellent. 7

To produce such high grade sulphurized oils I find it is advantageous to use, as the starting ma- 60 terial, commercial sperm oil having the following properties, for example, but not by way of limitation:

Specific gravity, 60/60F 0.878-0.884

Viscosity, S. U. V., 100 F 95-110 Flash, 0. c., minimum 49o Pour, F., maximum -i +40 Color, N. P. A., not darker than 1.5 Neutralization number, maximum--- 0.5

' Oleic acid eq., per cent, maximum 0.25

Saponiflcation number 125-135 Iodine number 80-90 The sulphur employed shouldbe of good quality and free of any abrasive material such as 75 sand, fossil fragments, etc. Sublimed sulphur,

such as flowers of. sulphur, is advantageous. However, any finely ground sulphur, such as sul-, phur flour, may be used.

The amount of-sulphur used to sulphurize the sperm oil may be varied according to the particu- 5 lar sperm oil being processed and the specific characteristics desired in the final product. Usually the ratio of sulphur to oil is between 5:95 and 20:80. Generally, I employ substantially an amont of sulphur not exceeding that necessary 1 to saturate the double bonds of the sperm oil used. In controlling the ratio of sulphur to oil, some unsulphurized sperm oil may be present in the final product. This is permissible as unsulphurized sperm oil is more or less a desirable and advantageous ingredient in certain lubrieating compositions.

By properly controlling the sulphurizing oper-' ation, for instance, by employing the methods given post, the percentage of combined sulphur in the sulphurized sperm oil is approximately that in the reaction mixture. Likewise, very little hydrogen sulphide is formed when the reaction is properly controlled.

In preparing the sulphurized sperm oil, the sperm oil is reactedwith suitable amounts of sul- "phur at temperatures between about 300-385 F.,

the reaction being continued until the sulphur is combined in the form of neutral organic sulphur compounds. However, to obtain superior sulphurized sperm oils, I find it advantageous to use reaction temperatures between 335 'and 360- F. and to employ controlled methods of sulphurization, wherein decomposition of the oil, side reactions, over-vulcanization, etc., are substantially avoided. If the sulphurization 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. 40

In general, control of the sulphurization 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 sulphur to the preheated oil, the

'rate of addition being adjusted so that heat developed during the addition of the sulphur gradually and quietly raises the reaction mixture to a temperature just below the preferred upper limit (360 F.) Advantageously, the finely divided sulphur may begradually sifted into the oil while agitating. After all the sulphur has been added, the temperature tends todrop slightly and then H the reactionmixture 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 pointcan easily be determined by diluting the sulphurized oil with a standard amount of mineral oil and determining its corrosive action upon a copper strip. When the copper strip remains unattached or shows only a slight stain, the reaction is eomplete. Then the sulphurized oil is cooled to about room temper- 5 ature. 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 relativecorrosiveness of lubricating oils. The procedure is 76 as follows:

A mechanically polished copper strip V inch by 3 inches'is immersed in 25 cc. of lubricant contained in a test tube whichis placed in a boiling water bath and held at the temperature of boilactions. heating, with the sperm oil preheated to between ing water for three hours. At the end of this time the stripis removed and adhering oil washed ofl' with a light naphtha and examined for evidence of corrosion. A negative test is one in which the strip shows only a slight stain or discoloration. The positive test is one where the strip shows considerable discoloration or tendency to scale, indicating presenceof corrosive constituents in the lubricant.

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

The sample of sulphurized sperm'oil is diluted with the above mineral oil in the ratio of 10:90 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 r in the above test.

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

The viscosity of the oil increases rather rapidly as the sulphur is added and upon combination of most of the sulphur 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 sulphur and exceedingly high temperature should be avoided to prevent undesirable side re- By way of specific example as to the 325-340 and the sulphur gradually added so as to bring the reaction temperature to between 330and 360 F., the maximum viscosity is obtained with 6 to 11 hours heating; all the sulphur Upon maintaining the temperatureat 340i5 F., all the sulphur can be brought into combination in the form of neutral sulphur compounds within 16 to 24 hours, with but a slight decrease in the viscosity during digestion. Thus by following the reaction by means of viscosity tests upon test samples withdrawn from the batch and by means of corrosion test made at about the end point, satisfactory sulphurized sperm oil may be readily consistently produced by my improved method; the details of ratios of sulphur to oil,

of rate of addition of sulphur and of time of heating being adjusted to the particular materials and equipment used in commercial practice.

From the description ante, the ranges of temperature generally used are between 325 and 360 F. and the time of heating is between 16 and 24 hours, the sulphur being added during the first any foreign bodies or abrasive materials that may have been accidentally introduced into the batch. As the sulphurized sperm oil is quite viscous, the filteration may be made while the oil is still hot.. Sometimes the sulphurized oil may be centrifuged, but ordinarily this is unnecessary when care has been used to exclude introduction of foreign matter. However, centrifuging can be advantageously used in later stages of the processing as shown post.

The controlled method of sulphurization here employed has several advantages. By first preheating the sperm oil, it is more or less dried during that step; the water and other volatiles being evaporated. Removal of these volatiles helps to minimize side reactions and the production of corrosive sulphur compounds. Further, the sillphur more readily dissolves in the hot oil and a uniform mixture of the reactants is quickly and readily obtained. Stratification of a heavy layer of molten sulphur and oil. frequentlyencountered in sulphurizing fatty oils, can be entirely avoided by the present methods. The sulphur being added in finely divided form to the so-heated oil 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 of the sulphur with the oil in the desired manner is immediately initiated and thus a high yield of neutral sulphur compounds is obtained. Likewise, the time of re-. action is held to a minimum and decomposition of the oil and of the neutral sulphur compounds sults may be attributed to the gradual addition of the sulphur in the manner set forth ante. In this controlled method there is a worthwhile overall efiiciency leading to a high yield of de-- pounded with any of the ordinary mineral lubrieating oils to modify the properties thereof. Varying amounts of sulphurized sperm oil may beemployed according to the compounded lubricant desired and the mineral oil base used. By

pblending from one-tenth per cent to thirty per cent by weightof sulphurized sperm oil pvith the various types of lubricating oils andgreases, I obtain a wide range of commercial lubricants wherein one or more properties of the lubricant are advantageously improved.

In my copending applications Serial Nos. 60,355 and 60,357, there are given numerous illustrative embodiments of such commercial blended lubricants containing sulphurized spermoil and like mono-esters. filed January'22, 1936, is directed to' improved My application Serial No. 60,357.

' lubricants containing sulphurized mono-esters of fatty acids.

Also the sulphurized sperm oils obtained by the present invention may be used in makingim-- proved pipe thread lubricants as disclosed in my copending application Ser. No. 60,356, (now Patent No. 2,065,248) filed January 22, 1936, that application being directed to such improved thread lubricants.

10 As stated ante, in lieu of sperm oil itself (oil employed. It is obtained from several species of go arctic sperm oil.

toothed cetaceans, particularly the bottlenose whale (Hyperoodon rostratum) hence the name of "bottlenose oil. It is so like true sperm oil in character, that the commercial oil is known as The said class of oils have certain properties in common with true sperm oil;

all of these oils containing characteristic types of fatty esters.

As is well known, true sperm oil is a mixture of certain esters. 'Ihose,esters are the esters of.

monohydric alcohols with fatty acids of the oleic series, such esters having the following general formula,

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 similarv 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.0f the ethylene series (the series of alcohols corresponding to the oleic series of acids). This characteristic class of mono-esters may be represented by the following formula:

. wherein n is at least 1. I

wherein a: is 1 to 7, are advantageous for making the said neutral sulphurized products.- In sulphurizing them by the present methods, the added sulphur saturated the double bonds of such esters yielding products having neutrally combined sulphur'in each half of the ester. Taking a the oleate of oleyl alcohol (oleyl ester of oleic acid) wherein the said a; of the above formula is 5, as an illustration, the neutral product may be represented by the following formula:

The following examples are illustrative em-.

bodiments of the methods broadly set forth ante and are not limitative of the invention.

Example 1.-*-This example illustrates an advantageous method. of'making the sulphurized sperm oil. A sperm oil having the following properties:

was sulphurized under controlled conditions, using approximately 12 weight on the oil.

Into a direct-fired, 20-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, 1098 lbs. of sulphur flour (approximately 1 lb. of sulphur 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 mixturev maintained at that temperature andstirred for per cent sulphur by 16 hours; the heating then being stopped and the sulphurized oil 'cooled to normal temperature. The total time from the first addition of sulphur 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 off during the addition of the rest of the sulphur;

but usually it is only lowered so as to prevent undue loss of heat by radiation. After the re-- action mixture is brought to 340 F., the-fire is increased to hold that temperature during the remainder of the reaction. e change in viscosity during the reaction was as follows:

After first addition of sulphur, hours at 0 n,

' seconds Viscosity, S.U.V.

.weight being 99.0

2,179,066 Operating in this way, there was obtained 9064 quality and had the following properties:

Gravity, A. P. I Y 14.1 Specific gravity, 60/60 F 0.9718 Pounds per gallon 8.093 Viscosity, S. U. V., 210 F 242 Pour, F +45 Sulphur (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 sulphurized oil, the diluted oil gave only a slight tarnish by the copper strip test.

In the above example the ratio and other details may be varied as indicated in the general description ante to obtain various specific products. In lieu of the particular sperm oil employed in Example 1, other unsaturated monoesters of fatty acids, such as mentioned ante may be employed.

For instance, any of the following esters which are typical and illustrative of the same general class of fatty mono-esters, may be employed:

Allyl oleate Decylene oleate Dodecylene oleate Pentadecylene oleate That in the broad practice of this invention there may be employed esters having the following formula:

wherein both R2 and R3 are olefinic aliphatic chains. Such esters are unsaturated (contain double bonds) in both the acid and alkyl components thereof. Generally, the esters of oleic acid and other mono-carboxylic acids of the oleic series with unsaturated mono-hydric wax alcohols may be employed. The acids ofan unsaturated aliphatic mono-carboxylic acid are esterified with the corresponding alcohols and are, so to speak, balanced esters. alcohol is typical of such balanced esters. However, the alcohol component of the ester does not necessarily have to correspond with the acid components thereof. The oleates of any of the oleyl alcohols present in sperm oil may be'used. The oleates are satisfactory and are ordinarily employed. Also, in lieu of natural mixtures of such esters, such as sperm oil, etc., any ester or mixture of esters of the general class set forth ante may be employed. That class is representative of the characteristic esters as sperm oil. That'is, -I may employ artificial or synthetic sperm oils comprising a mixture of such esters,

in lieu of the sperm oils directly obtained from natural sources. In. this way, the properties of the starting material and sulphurized. products 60 parts of sulphur.

The oleate of oleyl organic sulphides.

obtained may be controlled to obtain sulphurized esters useful for special purposes.

By the procedure of Example 1, various sulphurized sperm oils and like mono-esters havmay be readily obtained and these are advantageous as improvement agents for various mintemperatures between 325 and 360 F. with about 12 per cent of sulphur by weight on the said oleate, by reacting 500 parts of said oleate with There is obtained a sulphurized mono-ester containing 10.7 per. cent of sulphur and having a viscosity S. U. V. at 210 F. of approximately 200-300.

The oleate of dodecylene alcohol. may be likewise sulphurized. This oleate required 1438 per cent sulphur to convert it into a substantially neutral sulphide containing 12.5 per cent combined sulphur. In practice a good product is obtained by sulphurizing parts of this oleate with 14 parts sulphur. Again the decylene acid ester of decylene alcohol may be employed. It requires 17.0 per cent .of sulphur on the ester to convert it into a substantially neutral sulphide containing 14.9 per cent of combined sulphur.

While in-the foregoing examples I have described direct sulphurization of the sperm oil, I

ing the following properties:

Viscosity,-S. U. V., 210 F 200 300 Sulphur, per cent at times find it advantageous to sulphurize sperm oil in the presence of another oil, as for instance a petroleum hydrocarbon oil which may well be the same as the oil used for the base for manufacturing the compound lubricant. That is, some of the mineral oil is mixed with the sperm oil prior to the addition of the sulphur.

When a mixture of sulphurized esters is to be employed, I sometimes blend together two or more sulphurized products, instead of sulphurizing a mixture of esters. In this way a more direct control and adjustment of the properties of the sulphurized material, for addition to special lubricants, may be obtained. 1

In this specification and the claims, the term sulphurizing means sulphurizing with sulphur itself, that is, reacting and chemically combining sulphur with the aliphatic mono-esters set forth ante. Likewise in this specification and claims the sulphurized" esters are those .containing the sulphur in chemical combination with the mono-ester. These'sulphurized mono-esters are free of chlorine and are substantially neutral That is, the processes and products of this invention are characteristically different from the sulphochlorinated fatty oils and esters obtainable by reacting sulphur chloride with fatty oils, etc. I

What I claim is:

1. A composition of matter comprising the. re-

saturated aliphatic monovalent alcohol, said sulphurized mono-ester containing combined sulphur in both of the aliphatic chainsof the acid and alcohol components thereof and said sulphurized ester .being a substantially neutral organic sulphide and being free of chlorine.

3. As an improved oil, useful in making lubricants, a sulphurized sperm oil, said sulphurized sperm oil being a mixture of substantially neutral organic sulphides readily soluble in mineral oils and capable of improving the lubricating qualities of such mineral oils when dissolved therein in small amounts and being free of chlorine.

4. As an improved oil, useful in making lubricents, a sulphurized sperm oil having the following properties:

Gravity, A. P. I 13.6-14.6 Viscosity, S. U. V., 210 F 200-300 Pour, F +45 Sulphur, per cent 8-14 Neutralization number 1-1.5

said sulphurized oil being a mixture of substantially neutral organic sulphides, being readily soluble in mineral oils and being free of chlorine.

5. As a new product, a sulphurized fatty monoester comprising the reaction product of sulphur and an unsaturated aliphatic mono-ester having the following formula:

wherein R2 and R3 are olefinic aliphatic groups, said sulphurized mono-ester being a substantially neutrahorganic sulphide containing combined sulphur in each of said aliphatic groups and being free of chlorine. p

6. As a new product, a sulphurized fatty monoester comprising the reaction product of sulphur and dodecylene oleate.

7. As a new product, a sulphurized fatty monoester comprising the reaction product of sulphur and the oleate of oleyl alcohol. I

8. In the manufacture of improved sulphurized oil products, the process. which comprises preheating sperm oil ,to a temperature between 325 and 360 F., gradually adding finely divided sulphur to the hot oil and maintaining the reaction mixture at said temperature until a sub- :stantially neutral sulphurized oil is obtained.

9. The process of claim 8 wherein from 5 to 20 per cent sulphur is so added to the hot oil, the

sulphur being added at such a rate as-to mainsain the temperature during that time at about 360 F., thus producing a superior sulphurized oil.

10. The process of claim 8 wherein the said sperm oil used as the starting material has the following properties:

Specific gravity, 60/60 F 0.8'780.884 Viscosity, s. nEv. 100 F 98-110- Flash 0. 0., F., minimum 490 Pour, F., maximum +40 Color, N. P. A., not darker than 1.5 Neutralization number, maximum 0.5 Oleic acid eq., per cent, maximum 0.25 Saponification number 125-135 Iodone number 80-90 said oil being substantially free of solid waxes.

11. In the manufacture of sulphurized monoesters, the improvement which comprises sulphurizing a fatty mono-ester having the following formula wherein R2 and R3 are oleflnic aliphatic groups, by chemically combining said mono-ester with sulphur in an amount not exceeding that necessary to saturate the double bonds in said olefinic wherein a: is 1 to 7, by chemically combining said mono-ester with sulphur to saturate the double bonds of said ester and obtain a substantially neutral organic sulphide readily soluble in mineral lubricating oil.

.15. As a new composition of matter, a stable addition product of sulphur and a naturally occurring unsaturated ester of a monohydric alcohol and a high molecular weight fatty acid, said sulphurized ester being free of chlorine and being a substantially neutral organic sulphide.

' HERSCHEL (3:. SMITH.

which comprises