US2922764A

US2922764A - Ricinoleyl lubricants

Info

Publication number: US2922764A
Application number: US465446A
Authority: US
Inventors: Thomas L Boswell; Davis Claude Manning
Original assignee: Elgin National Watch Co
Current assignee: Elgin National Watch Co
Priority date: 1954-10-28
Filing date: 1954-10-28
Publication date: 1960-01-26
Anticipated expiration: 1977-01-26

Description

RICINOLEYL LUBRICANTS Thomas L. Boswell, Elgin, Ill., and Claude Manning Davis, Plainfield, N.J., assignors to Elgin National No Drawing. Application October 28, 1954 Serial No. 465,446

20 Claims. 01. 252-481 This invention concerns lubricating materials containing the ricinoleyl group and characterized in having a low humidity effect.

Since portable timepieces have been made, the problem of finding suitable lubricants for these mechanisms has been attacked by many people associated with the horological industry. Until the wrist watch came into prominence, satisfactory lubricants had been found among the naturally occurring oils. The best of these were the animal and vegetable oils consisting essentially of glycerides of the fatty acids and blends of these oils with mineral oils to obtain desired viscosity and some measure of resistance to chemical change with time. With the coming of the wrist watch and particularly since fashion has demanded mass production of smaller and smaller watches, the problems have become intensified. Until quite recently efforts to further refine and blendthenatural oils have resulted in some improvements but all natural and blended-natural lubricants now available commercially are compromisesnone of which is entirely satisfactory, for one or more reasons.

It has long been known that glyceryl tri-ricinoleate (even in the crude commercial form of castor oil) hasacceptable lubricating properties under conditions where the high viscosity and the possible presence of moisture can be tolerated. For example, in internal combustion engines which operate at above the boiling point of water and high power is available, castor oil has been used for lubrication.

Many attempts have been made to use it for instrument lubrication but its exceedingly high viscosity has militated against its use in spring-driven machines, particularly where space was so important that small power springs were necessary. These springs do not possess the necessary power to drive through the viscous fluid. For example, where low powers only are available, as in the smaller wrist watches, escapement lubrication is desirable as such watches in commercial runs have low amplitudes of motion in the initial absence of such lubrication; on the other hand, most present lubricants soon disappear from the escapement contact surfaces and the-friction constant changes: the instant lubricants have been found excellent and long lasting for escapement purposes. For example, fresh ricinoleic acid soon becomes thicker, and this increase in viscosity may be attributed to the formation of intra and inter esters. Ricinoleic acid has a terminal carboxyl group and a branch hydroxyl group. The reduction of ricinoleic acid to ricinoleyl alcohol by sodium involves the resolution of such esters, with conversion of the carboxyl group to hydroxyl, and the resulting alcohol with terminal and branch hydroxyl groups is known: it exhibits an improved and more stable viscosity behavior, and has been found to have lubricating properties but the ricinoleyl alcohol formed by sodium reduction has a bad humidity or hygroscopic action.

A primary feature of the invention is the provision of improved lubricants for watch escapements; it being recognized that materials satisfactory for such use are also 2,922,764 Faiented Jan. 26, 1960 useful for-other watch bearings and on watch mainsprings, and for other instruments, particularly where high unit bearing pressures exist.

'Anotherfeature of the invention is the provision of a lubricant comprising a compound which has the ricinoleyl radical "coupled through oxygen or sulfur to another group; and characterized by low volatility, and low hu- Watch Company, Elgin, 111., a corporation of Illinois midity effect. I Another feature is the provision of a lubricant comprising a compound which has the ricinoleyl radical coupled by oxy or thio ether linkage to another hydrocarbon group or groups; and characterized by low volatility and low humidity effect.

Another feature is the provision of a lubricant which permits operation of timepieces and like devices at very low temperatures, which is of particular value for aircraft instruments and other military instruments in general.

Ricinoleyl alcohol was made and proved to be an ex- TABLE I Properties of various batches of ricinoleyl alcohol Batch No. Cut N0. Acid No. Refractive Index Undist For batch No. 13, cut (1) was obtained by steam vacuum distillation at to 193.5 degrees C. and a pressure of 2.1 to 2.2 mm. Cut (2) was from a continuation of the steam vacuum distillation at 193.5 to 200 degrees C. at, 2.2 to 2.3 mm. pressure.

When ricinoleyl alcohol prepared in either fashion is subjected to an ether-forming reaction, its humidity factor is improved immediately, even before any notable ether formation occurs: possibly from a heat-induced isomerization effect, as infra-red studies indicate that the previously absent trans isomer develops. In particular, it has been found that the trans isomer has greatly improved lubricating effects, as in its absence the motion is low when the ambient temperature is low.

It is further notable that ricinoleyl alcohol prepared from commercially pure ricinoleic acid by the lithiumaluminum hydride procedure does noL'have the high humidity efiect that is shown when the reduction is carried out by means of the known sodium procedure.

TABLE 111 Motion vs. temperature of movements lubricated with di-n-amyl thio-ether of ricinoleyl alcohol Average motion of movements Duration of (Grade C.) Trans- -Prepara- Test mit- 7 PertionNo. (Months) tance cent Room 0 35 50 65" v Temp. F. F. 1f.

1. 45 1. 45 1. 36 1. g? 1.55 1.35 1. 5 0. 6.- 1.38 1.38 0.96 0. 75 0.68 83/40 43 10.46 (end). 1.43 1.21 0.87 0.74 0.66 Original 1. 84 1. 30 1.20 1.06 0.84 1. 30 l. 45 1. 35 1. 21 1. 14 1. 29 1. 29 1. 20 1. 0.91 85/48 37 1. 30 1. 23 1. 08 0. 89 0. 75 1.28 1. 14 1. 84 1.35 0. 3

as 3a .31 1.20 0.80 0.33 }82/75 1. 53 1. 49 1. 38 1. 08 I 1. 59 1. 56 1. 46 l. 15 1. 56 1. 53 1. 36 1.05 82/48 34 1. 55 1. 50 1.31 1.04 1. 60 1. 49 1. 29 0. 96 1. 40 1. 07 0. 79 0. 64 1. 49 1. 26 0. 83 0.75 85/68 17 1. 54 1.05 0.86 0. 74

The Watches were a test group of ten movements of identical type, size, and grade, so that direct statistical averages could be obtained; having the usual tolerances of adjustment of bearings, escapements, etc., and the lubricant was employed at the several bearings. It may be remarked that when the adjustments are refined to high accuracy, the lubricant is satisfactory regardless of physical state even as low as minus 110 degrees F.; that is, the physical behavior of the lubricant, such as an intervening freeze or pour point, does not prevent lubricating action down to such temperature.

The transmittance is set out as the dip of the standardized graph representing the transmission factors at the successive infra-red Wave lengths, so that the numbers 83/40 represent a top value of 83 on the graph adjacentthe wave length at which there is response to the trans isomer form, and a value of 40 for the dip at this response wave length: the difference being the value 43 or 52 percent of the top value of 83. A difierence of /5 or 20percent or more having been found to represent a satisfactory condition for desirable motion .amplitudes at the lower temperatures.

In test groups of watches, as described herein, there may be variables as high as 10% due to mechanical tolerances, strength of springs, etc., at various conditions of test. The' ave'raging results therefore are more representative than the' efiects of any single movement. It is noteworthy that these variables are not normally efiec= tive at room temperature, but come largely into play at temperatures of, say, minus -degrees F. and below, so that watches which may appear closely similar at room temperature .Will have variant conditions at these low temperatures. In each of the examples herein stated, the watches continuedto run (unless otherwise stated) at the lowest temperatures marked. It may also be noted that three-quarters of a turn of movement has been acceptable at minus degrees F. heretofore: and one turn at minus 35 degrees F. Accordingly, it is note: worthy that many of these materials are far more satisfactory than required by present specifications.

Preparations Nos. 3 and 4 were not distilled for purification of the ricinolcyl di-iodide; whereas distillation was used with Preparations Nos. 1, 2 and 6. Preparation No. 5 was made by combining residues of Preparations Nos. 3 and 4, and then vacuum distilling with water vapor.

Blends of one or more of the mixed ethers with other lubricants are valuable and included herein. For example, diphenylheneicosanone is a lubricating liquid having excellent surface tension and retentivity to metal and sapphire surfaces, but exhibits a humidity effect: when mixed in equal parts by weight with ricinoleyl-di-n-amyl thio-ether (see Example XXI), the humidity effect of the mixture isso low that no attention need be paid to the condition, and the surface tension lies Within the desired range of 29 to 36 dynes per centimeter. It may be noted that when the surface tension is below 29 dynes per centimeter, the material exhibits spreading on brass and ruby; within the range of 29 to 33 dynes per centimeter, the material is slow spreading or may be designated as a borderline lubricant; while at about 33 dynes per centimeter and up, the material does not spread in a period of three months or moreas noted, in commercial uses in watches, etc.

The following shows .the behavior of mixtures in parts by weight containing such ethers, the di-n-amyl thio ether of Example XXI (here abbreviated as ATE) being selected for direct comparison, and employed in mixture with diphenylheneicosanone (noted as dPH), Whose properties alone and in mixture with phenylstearyl alcohol (noted as PSA) are inserted for the comparison. Dodecyl piperidine stearate is noted as DPS.

TABLE IV (Ladles wrist watches, 19 jewel, Grade A) Atmosphere, Atmosphere, Humidity Y 60% RH. Effect Example Lubricant 1 hr. 24 hrs. 1 hr. 24 hrs. 1 hr. 24 hrs.

dPH 1. 350 1. 200 1. 075 0. 925 0. 28 0. 27 XXI- dPH: 20 PSA 1. 324 1. 275 0.974 0. 874 0. 35 0. 40

ATE in 1.500 1.437 1.387 1.276 0. 11 0. 16 XXVI--- 50 dPH: 50 ATE 1. 500 1. 402 1. 252 1.126 0. 25 0. 28 XXVIL- 80 dPH: 20 ATE 1. 412 287 1. 127 1. 039 0. 28 0. 25

TABLE IV-A (Ladles wrist watches, 19jewe1, Grade B) Atmosphere, Atmosphere, Humidity dry 60% RH. Efiect Example Lubricant 1 hr. 24 hrs. 1 hr. ,24 hrs. 1 hr. 24 hrs.

dPH 1. 474 1. 375 1. 324 1.127 -o.15 0. 25 XXI.--" 80 dPH: 20 PSA- 1. 513 1. 425 1.387 1.239 0. l3 0. 19

ATE 1. 604 1. 513 1. 578 1. 474 0. 03 0. 04 XXVI--- 50 dPH: 50 ATE 1. 565 1. 500 1. 451 1. 439 0. 11 0. 06 XXVIL- 80 dPH: 20 ATE 1. 513 p 1.437 1. 437 1.238 0. 07 0. 20

TABLE 1V4! (Ladies' wrist watches, omen) i Atmos her i Amos here Humidity or? -eo% in. new Example :Lubmant v m. etmf 1hr. 241115. 1111. 24m.

'murHrzso-x'rn (m2 1.565 1.500; 1.451 11.439 -o.-11 -o.oe

TABLE IV-;C

(Ladies' mist'watches Grade LB) Atmosphere, Atmosphere, glumidlty dry 60% RH. Ef ect Example, Lubricant 1hr. :24:hrs. 1hr. 24hrs. 11hr. 24111-3.

xxrx--- 'fin'dh-EireoghTE flotm 1:125. 1.18. 1.13 1.01 +0.12 -o. 1 1 xxx... 50 GPHLSQATE onnrs (101; 1 1.23 1.11 1.1:; 109 -0.10 -0. s

*It'may lac-stated that themixtures of-dPH and ATE have higher retention factors than ATE alone, 'therewith overbalancing "for "lengthy commercial uses, between. relubrications, initially higher motions for 1 the ATE. The other oxy and thio ethers -'eXhibit like behavior tin mixtures.

For Example XXX, the*material showed .a :retention factor at -3 months of 8-9.3 percent; at:6 rmonths, 'I-8;5 percent. Thefailures of lubrication (ZOWatches-running continuously to failure) were none at 3 months one at 6 months.

The column headed Humidity' -Etfect sets out the change in number ofturns .due to hurriiditypand the values :are thedifferencesbetween values-in the "Atmosphere Dry emi -Atmosphere; 60% R .H. (-60% 1 relative humidity) columns.

'lur'therinstances. showing the efiect'of additives upon the viscosity, the comparison being between the dry composition and the composition after exposure for 5 days at 100 degrees C. to=an atmosphere provided by passing air through waterat" C. to procure-saturation =an'd then heating; the resultant: relative humidity at 100 C. beingiabout Spercent, are as follows:

mAnLEw Comparison of watch lubricant additives in their 'efiect upon change of viscosity during corrosion rests Example XXXI was T mi 1) with added 5 d.

oxidant (1% 2,6 tertiary. butyLp-nresol. and 0.2% trithiophenyl phosphate).

--Bxample'XXXII-Was'99%" by'weight'ricinoleyl alcohol and 1% hydroquinone.

ExampleiOOflII was 'the ether of :Exam'ple -XVI, with thesame anti-oxidant a*Exan1ple-1XXXI and'inthe same amount.

Example XXXV-Wasthe ether of'ExampleXXI, with the same antioxidant asiiExample'XXfl and inthe same amount.

,In .the above table,one anti-oxidant employed for thetests.was..2,6.tertiary-buty .pr an r t wpheny P Q$Phate ina mix urefound bette th .e .the .alons- Qther...anti.-.oxida.nts vcanybe used, such as p-,tertiary; hut yl catechol, .triphenyl phosphate, and similar organic 0,9111? pounds. such, as 1 polyhydroxyphenols and phosphat e ester s of .the phenols. In general, the addition p-fnhoht 1 10.1.5 percent by weight .of vanti-oxidant,is desir hie whenever ,the lubricantjs to ,he .used in contact with metals. whicharesubiect .toc orr.o'sion.

It'has above'beenstated that thehumfiflxefiestis revealedquickly. Tov show that theetfect occurs heiore moisturetsaturation ,of the materiahhas ,.oc. hr ed,.the following sets out theflbehavior.of.,.dried.9i1s;in a;humid atmosphere. 'Forthetests clean lO mLnbeakers were weighedand about 5 .grams of. the statedihtbricating gil .aiddedgthesamples were heldin adesiccator overico n- .centrated sulfuric. aciiuntilconstantweightwfis, reached. The samplesof dried- .oil werethentransferred, to. a closed vessel containing.a '.atutated solution ,of amn qninni gulfate. untilponstannweigh as aga nnhtaine .Ih ...t h

were conducted at room. temperature. 'Ihe, results yvere reported. aspercent. (1% 1. of water. (by Weight) .ahsqrbed .pergramntthedrieioil- TABLE VI H um d ty tests on oils Num. hweight Weight Percent Days in Dry on Wet on Gm.H O H OAb- Wet Identification over over Gained sorbed Cham- H 801 (NHQ SOi per gm her to dry oil Const.

Weight G. G. 6'. Percent Commercial 53 7 1. 8946 1. 8982 0. 0037 0. 195 24 Commerc al C v 3.0046 3. 0062 0. 0016 0. 053 17 Commercial D 3. 3730 3. 3767 0. 0037 0. 17 Castor 011, USP"--- 4. 7728 4. 8067 0. 0339 0. 710 72 Example I 8 4. 75 Example XII- 4. 7676 4. 8242 0. 0566 1. 187 86 4. 9354 4. 9881 O. 0527 1. 067 21 4. 7190 4. 7747 0. 0557 1. 86 4. 7392 4. 7940 O. 0548 1. 156 98 4. 5731 4. 6214 0. 0483 l. 056 24 4.1057 4. 7854 O. 0797 I. 693 82 5-127 (2) (2) (2) a 4. 76 (a) (a) (a) w and gained 0.0036 goin 74 days later.

Approximate. 1 Sample .neverreached ppnst. dry weight. Lost 0.0319 g. in 47 days Kept in dessicator for 122 days. I-Never reacheddry constrsveight. Gained 0.1319 g. in 122 days over 2304. I l T propyl ether otrncmoleyl alcohol .and 1%..hyd10qu1nonea 751 .05 reached cQnst' Weight H250 tom gum in 122 was s It may be pointed out that the humidity effect is often not directly ascertainable by the percentage of moisture present or by laboratory tests of surface tension. Experimental determinations have been made by carefully cleaning a group of identical good watch movements (e.g. ten), lubricating them with the test material, and then causing them to turn for 48 hours in a desiccated atmosphere of -20% relative humidity, and noting the individual levels of motion when fully wound and when 24 hours down (i.e. after running 24 hours from the latest winding). The watches are then caused to run in a controlled atmosphere of 50-60% relative humidity (i.e. corresponding to a normal atmosphere in the United States); and the levels of motion are observed as before by winding, noting the motion, running 24 hours, again noting, rewinding, noting, again running for 24 hours, and making a final note of the motion level. The averaged results for the group of watches are closely reproduced when the test is repeated. It is striking that changes in level of motion appear, in a change from a drier to a moister atmosphere, in about minutes; and quick qualitative values can be obtained by partly winding a cleaned and lubricated watch and observing its motion after a couple hours in a dry atmosphere, then immediately transferring it while still running to a moist atmosphere and observing the motion at the end of a half hour.

An outstanding effect of the presence of the ether in such mixtures is in the further reduction of viscosity of 'power to be taken from the mainspring and trans-=- mitted to the balance wheel at regular intervals of time. The efliciency at which it operates determines to a large extent how efiiciently the power of the mainspring is I utilized. It is imperative in small watches that this be utilized quite efficiently in order to provide a satisfactory interval between windings.

During the operation of the escapement, the knifeedge of the escape wheel travels across the impulse face of the ruby stone or jewel pin. Each stone is thuswiped by a knife edge 2 times per second in the usual S-beat watch. Attempts to calculate logically the unit pressures existing at this point result in an ex-' tremely high value; it is generally conceded that the unit: pressures in watch escapements are determined by the: lowest yield point in compression of the materials in con-- tact. Under the most optimistic reasoning, the pressures.

are much higher than is consistent with fluid lubrication.

theory. Thus in this instance there is a condition off boundary lubrication where viscosity plays only a smalli .part in reducing friction and the factors effecting satis'-- factory lubrication here are as yet but little understood.

The lubricants, being capable of such employment, are also useful for other purposes. For example, they give satisfactory results at the mainspring,

Comparative physical properties and corrosion behaviors of some commercial watch lubricants and the instant ricinoleyl others are shown by the following table:

TABLE VII Physical properties of selected compounds compared with commercial watch ozls Viscosity Percent Change in Percent Viscosity Relative Surface Ether After Volatility Chemical Density Tension (=l=10% corrosion Percent F. 68 F. Accuracy) (100 F. loss in Based on hours Original Vis.)

Synthetic Lubricant A 0. 920 31.0 29. 4 Synthetic Lubricant B 0. 926 1 34. 0 41. 5 0. 894 31. 0 47. 7 0. 980 35. l 304. 3 0. 908 34. l 167. 0 0. 867 30. 7 10. 6 0. 908 34. 9 53. 1 0. 904 32.0 37. 6 0. 890 31. 0 51. 2 0. 916 35. 1 49. 8 0. 925 31. 1 79. 9 0. 900 34. 4 59. 1 0. 910 32.2 91. 1 0. 918 33. 6 38. 1 0. 878 30. 4 46. 3 0. 890 31. 7 72. 4 0. 890 34. 2 65. 2 0. 910 33. 8 63. 8 Example XXL 0. 860 30. 6 8. 7

wheel. This part of the watch permits minute amounts (5 value stated).

Like comparisons of the behaviors of lubricants of Table VII, in watch service under close observation and maintenance of a humid atmosphere, are given below in- Table VIII.

The columns are headed as before, with parentheses marking specific variant readings obtained. The last two columns show the number of dry jewels found out of j with 2 jewels each, for each} 20 (10 watches under test,

- TABLE VIII Results ofwatch tests of selected compounds compared with comm erczal watch oils Average Escapement, 112 hrs. running Humidity Retention N 0. Dry NosDry Motion Jewels Jewels. Chemical 1 (out of (out of Move.) L R 1 hr. 24 hrs. 3 mos. 12 mos. )v 20) (-12 mos.) mos.)

CommercialA 1.46 Dry track Dry track A Commercial-B... 1. 54 (1 do 100 Commercial 0... e 1. 64 l 80 Castor oil, Fisher 1; 26

Example I I 1.625 93(78) (85) Example II. 1. 5 77 ExampleXII 1. 5; 63- Exa pleIII. 1. 625 58(71) Example IV- 1. 625- xsmp e vr. L62 78 Example VI l. 50 67 Example XVII 1. 50' ExampleVIIL l; 50 f Example XVII 1.55 92. 0 Example IX 1.50 3 Example X: l. 50 74, Example XIX. 1 1. 50 g 88.7 Example'XV'. 1. 50 70 Methods of preparing suchcompounds willnow bedescribed;

PREPARATION s. .RIcr o Yn ALCOHOL Ricinoleic acid' is commercially obtainable, and .has

,refiux condenser and opening for a dropping funnel is added 3560 cc. of dried di-butyl ether;

To thelether in the flask is then added lb. (ll0l20 grams) of lithium aluminum hydride.= The'slurry is-thenistirredfor several minutes.

the slurry while stirring. Therate of addition is govcrncd bythe temperatureandrate-of evolution of hydrogen The temperature should not exceed; 90 C. during this additionfMfore solvent maybe added if-the contents oithe flask become too thick. The mixture is heated gently for two to three hours after the addition istcomplete, keepingthe temperature betWeenJOTSOf C. After this period,vthe heat is removed and the reaction flask. is. surrounded with an ice-water bath. About 2501cc. of cold water is:v then added dropwise: the first. few. hundred drops should be added one drop atfa time, allowingj up to half a minute betweencach dropfor 'the-first ten to twenty minutes. The mixturef is then hydrolyzed by carefully adding two to three liters of 20% by weight of sulfuric acid. The product is; then washed 10 neutral with distilled water-,5 dried over about-one pound of-janhydrous calcium-sulfatewith some anhydrous sodiumsulfate. The solvent is -stn'pped b'y distillation at atmospheric pressure: for a yield of about 99 'p ercent. The alcohol need not be distilled since it can be. used .insubsequent syntheses- Di-ethyl ether can be used as solvent, but dibutyl ether is preferred, for its higher boiling point, as this permits a higher reaction temperature with corresponding increased velocity, and with a greater ease of condensing during reflux.

PREPARATION B.-DT-IODO-OCTADECENE This intermediate (l,l2;diiodooctadecene:9 used in the preparation of the Then 420430 grams of dried ricinoleic acid diluted with 300000. of dibutyl ether-is added slowly to thioethers of ricinoleyl alcohol and, also. i in an alternate.

methodjtor the preparation of the oxyethersotrici'noleyl alcohoh} is prepared fromricinoleyl alcohol: and phos: phorus tri-iodide as follows:

To a three-necked round bottom, twolite'r flask,

equipped with a -mechanical stirrer, reflux condenserand" dropping funnel is added first 23 grams of red amorphous ph'osphorusthrough a powder funnel. Then" 375 grams of iodine (resubliined) dissolved by'shaking with 300"- grams of dried ricinoleyl alcohol, is added through a separatory funnel with no solvent. The first addition is done cautiously. Cooling with ice water is necessary. After this initial reaction subsides, more of the iodine and alcohol are added slowly with stirring. If the reaction does not continue as evidenced by evolution of heat, gentle heating may be necessary. After the addition'of the alcohol and iodine is complete, the mixture is heated to about -140 C. and held at this temperature for three hours; The heat is then removed and the product allowed to cool slowly and stand overnight. The iodine fumes may be absorbed by a solution of sodium thiosulfate or sodium hydroxide. A trap should be used to avoid sucking back.

The product is then diluted with diethyl ether, washed with three portions of 5% sodium hydroxide followed by several washes with distilled water to neutral. The mixture wasthen dried; over anhydrous sodium sulfate, filtered and stripped-of solvent, diethyl ether. The residual solvent was removed by decreasing the pressure at the'end'of thedistillation-process. Since it is an intermediate, it was not further purified.

In-Preparation l3, when the di-iodo-octadecene is distilled by'the water vapor-vacuum method, a significant increase in'the trans isomer content is noted: and this proceduralstep; canbe employed for such purpose.

Infra-red analysis of: the product showed the absence of hydroxyls, indicating very pure yields.-

PREPARATION-C. RICINOLEYL DI-OXYETHERS FROM RICINOLEYL ALCOHOL The structurallformula-for the di-oxyethers of ricinoleyl alcohol (i.e. the ricinoleyl oxy diethers) is:

CHs(CHz)5(I3HCH2CH=OH(CH2)aOR where R and R may be the same or difierent groups and where-R and'R are straight orL branched chain- Thesymmetrical ethers (whereR and R? are--tlie sam,c-)-= are more easily prepared than the unsymmetrical:

' added to the cake, stirred, and separated again.

Though several methods have been employed, the most successful procedure for use in preparing di-ethers with very little or no alcohol in the final product is represented by the following equations:

(Where Hx represents a halogen; and R is the other group for the mixed ether). In the first equation, the sodium may be combined with other materials prior to reacting it with ricinoleyl alcohol to avoid the use of lumps of metallic sodium, which quite often become coated with the solid alcoholate before the reaction is complete. Sodium methylate can be used. Satisfactory materials are the commercially available sodium dispersions in non-reactive organic liquids, e.g. toluene, where the diameter of the sodium particles is in the range of 1 to 18 microns.

The general procedure for synthesis of the diethers is as follows:

To'a three-necked round bottom two liter flask, equipped with a reflux condenser, mechanical stirrer, and dropping funnel is added 0.61 gram atomic weight of sodium in the form of a sodium dispersion in toluene. The dispersion is further diluted by addition of 600 to 700 cc. of toluene (previously dried over sodium). After warming the contents of the flask to 50-60 C., 0.3 moles of dried ricinoleyl alcohol (from Preparation A above) diluted with 200 cc. of dry toluene is added dropwise with constant stirring to the sodium in the flask. Care should be taken to avoid rapid addition of the alcohol in order to avoid forming a complex of alcohol with the alcoholate. After all the alcohol is added, the contents of the flask are stirred for thirty minutes while the solvent is gently refluxing. While still refluxing 0.63 moles of the RHx, diluted with 100 to 200 cc. of toluene, is added dropwise with stirring to the alcoholate. The heat may be reduced if excessive refluxing is encountered on adding with halide. After all the halide is added, the mixture is heated to gentle reflux and maintained at this temperature with continued stirring for ten to twelve hours. The flask contents are then allowed to cool to room temperature with no stirring. The reaction mixture is then separated into a solid and a liquid portion by centrifugation or other means, avoiding contact with moisture insofar as feasible. Separation by laboratory filtration was found very difficult. The solid matter collected is the sodium halide (a reaction product) and unreacted sodium alcoholate of ricinoleyl alcohol. The liquid portion consists of solvent, unreacted halide, and the di-ether of ricinoleyl alcohol. To wash the solid portion to remove as much of the di-ether as possible, the filter cake or solid portion is transferred to a beaker, a small quantity of toluene The liquid portions are then combined and transferred to a separatory funnel. The liquid is then washed with acidulated (HCl) distilled water, then washed with distilled water until the spent wash water has the same pH as the original water (by indicator paper test). The final wash Water is drawn off and the reaction product is dried over anhydrous calcium sulfate or anhydrous sodium sulfate. After drying, the solvent is removed by distillation at atmospheric pressure, the last traces of solvent being removed by reducing the pressure at the end of the distillation process. The crude product is then purified by water vapor carrier-vacuum distillation.

In a preparation of diphenylamyl ether of ricinoleyl alcohol, the product had an acidity equivalent of 1.13 mg and behaviors as set out for Example XVIII herein.

PREPARATION D.RICINOLEYL MON O-OXYETHERS The formula for the mono-ethers of ricinoleyl alcohol (or ricinoleyl mono-ethers) is as follows:

( 1 CH CH CHOHCH CH= CH(CH OR (primary ether) and/or (2) CH3(CH2)5?HCHQCH=CH(CH2)BOH (secondary ether) Unless special provisions are made, a mixture of both the compounds represented by the above formula is prepared plus a smaller proportion of the di-ether. Since such precautions are lengthy and expensive, and since mixtures tend to depress the pour and cloud point and in general improve the lubricating qualities, no special precautions need be taken in the preparation of satisfactory mono-ether mixtures for lubricants.

The general procedure for synthesis of the mono-ethers is as follows: to a three-necked round bottom two liter flask, equipped with a reflux condenser, mechanical stirmi, and dropping funnel is added 0.41 gram atomic weight of sodium in the form of a sodium dispersion in toluene. The dispersion is further diluted by addition of 600 to 700 cc. of toluene (previously dried over sodium).

After warming the contents of the flask to 50-60 C.,

0.4 moles of dried ricinoleyl alcohol (from Method A above) diluted with 200 cc. of dry toluene is added dropwise with constant stirring to the sodium in the flask. Care should be taken to avoid rapid addition of the alcohol with alcoholate. After all the alcohol is added, the contents of the flask are stirred for thirty minutes while the solvent is gently refluxing. While still refluxing, 0.42 mole of RHX, diluted with to 200 cc. of toluene, is added dropwise with stirring to the alcoholate. The heat may be reduced if excessive refluxing is encountered on adding the halide." After all the halide is. added, the

mixture is heated to gentle reflux and maintained at this temperature with continued stirring for eight to ten hours. The flask contents are then allowed to cool to room temperature. The reaction mixture is then washed first with acidulated (HCl) distilled water, then with distilled water in a separatory funnel until the spent wash Water has the same pH as the original water (by indicator test paper). The final wash water is drawn off and the reaction product is dried over anhydrous calcium sulfate or anhydrous sodium sulfate. After drying, the solvent is removed by distillation at atmospheric pressure, the last traces of solvent being removed by reducing the pressure at the end of the distillation process. The crude product is then purified by water vapor carrier-vacuum distillation.

PREPARATION E.RICINOLEYL THIO-ETHERS point of compounds as against a gradual thickening and solidifying which takes place as mixtures are cooled to successively lowered temperatures, such thickening being due to components separating out of the solution phase and giving rise to wide freezing ranges, except in the special cases where a eutectic point exists below the desired operating temperature.

ambiance."

The gener'a.1 formula for the thi'o etliers of ricinoleyl' alcohol: (Le. ethers of di-mercapto-oc'tadeceneQ) as follows:.

where R'and' R may be the same or different groups, and where-R and. R are straight or branched chaimalkylor aralkyl or aryl groups,- the alkyl chains having from 1 to 18 carbons and the alkyl chains of the aralkyl group having froml to ll'carbons.

To illustrate this synthesis, the procedure which follows is for the preparation of di-n-amyl thio-ethef of ricinoleyl alcohol.

Two equivalent weights (80 grams) of sodium hy droxide were dissolved in the smallest possible quantity of. water and diluted with methanol: a solution in methanol of two equivalent weights (208 grams) of namyl; mercaptan was added through a droppingv funnel with stirring. 176 grams ofthe 1,12-diiodooctadecene- 9 from Preparationv B above, in methanol, was thenv added through a dropping funnel with stirring. Further dilution with methanol or toluene may be employed. The mixture was then refiuxed for six hours and allowed to cool. The following day, the mixture was transferred toaseparatoiy funnel and the clear aqueous layer withdrawn and discarded. The oil; layer-was diluteda solvent such as di-butyl ether; washed with.5% sodium:

hydroi ide solutionand then neutralized by washing-withd1st1lled water, until the efflux pH is thatof theentering:

water; withdrawing the successive water fractions; as: settled; the, oil layer was thendried over. anhydrous calciumor sodiuin sulfate, andstripp'ed of' solvent-:by-

distillation.

The thio-ether was then-purified .byyacuumdistillation;

usiufgl water vapor as carrier, withvapor temperatures:.=of' 200-250 C. at around. 10 mn1. pressure.-.- Thexproeluct: obtainedwas a dark amber liquid; and provided 'a. lubricant satisfactory at normal temperatures. 01111311111 fying further by chromatography, a pale yellowliqu'id wasobtained. The original .color andwide boiling-range.

maybe accounted for: by the presence'ofunreacted di-- iodooctadecene. The behavior of this; compound isIde-.- scribed herein -as Example XXI.

The quantities indicated above includeuse 'ofrsodium" hydroxide and rhercaptan inlarge excess overthe di halide compound (of which .one equivalent weight isa508- grams) to, .1 assure essential exhaustion: of the. expensive; di halide component before the unreacted ,materials are separated.

The reactions may be regarded as proceeding-z (1)' RsH+NsoH- RsNa+H o (2) onaonmon- CH:-,CH(CH2)11I: 2(RSNa).

Alternative procedures, using-differing amounts .oftthe (ii-halide, and with other purification procedures, have ledgto 1 the production of the compound-:-- man oes the vacuumwdistillation: with water vapor carrier is -etfectivein assuring a-large proportion ot trans isomer.

It :hasibeemfound thatzthecondition'stduriing' synthesis may be'critical if the: best lubricating;compositions are to" result: 1. although thevarious syntheses produce lubricants efiective at. normal= temperatures.= For example; several-.-

of the compoundswere synthesized by several procedures: theproduct by oneprocedurehad a much higher viscosity andJa higher surface tension, and gave a poorer motion when. usedin watches below minus. 10, degrees F.,. as-

compareii with the product byPreparation B; As the viscosityof' the former product was not sufii'cientlyhigh to account for the poor motion, thus encountered iii watches at low temperatures, it must 'be'co'ncluded that theqprodnct does not possess the excellent lubricating propertiesof thepreferred material made in accordance with; Preparation E; noting that the former product was low in trans isomer. However, when the former prod not was then subjected to vacuum distillation with water vapor carrier,., to give a high content of trans isomer, it

provided a lubricant of light high quality even at the low temperatures.

PREPARATION F.-RICINOLEYL THIO-ETHERS (SECOND METHOD) An alternative procedure to that of Preparation E is by placinglhediiodooctadecene from Preparation B and the mercaptan (here, illustratively, phenylamyl mercaptan) in a flask, with toluene as a diluent. These are heated with refluxing for 30 minutes, and then allowed to cool. It is preferred to use less than the theoretical equivalent amount of the dj-ha'lide compound, because of its-cost andto assure its total consumption in the 'reactior'rz. the mercap'atn and caustic alkali are each. present in proportions of two equivalent weights as before; The sodium hydroxide is dissolved in the least necessary amountofamixture' of equal parts of water' 'and methanol: and introduced dropwise to the-flask with stirring; The' material is then heated with refluxing for 6 hours.

Thereafter, it is cooled, separated,- and purifie'das in Preparation E above;

The reaction may be regarded as illustratively pros whreR designates the phenylamyl group in the above example ofprocedure. Other illustrative groups at the R positionsare n-amyl, n-propyl, isopropyl, n-octyl, ph'enyl propyl. v

The products were found to have high retention factors. Di-phenylamyl thio-ether of ricinoleyl alcohol (EX ample XXXVI) has a surface tension of 34.03; a vi's cosity at 68 F. of 46.29 centistokes, at 100 F. 01:22.57"

centistokes; and behaves (compare Tables IV and IV A) asfollowsz The following are illustrative of the behavior of thioethers during low temperature tests:

TABLE X Low ten'z p'r'ature watch tests on thio-"ethe'rs of 'ricinol'eyl alcohol Motion at; Indicated Temperatures (FJ Lubricant r EiiampleX'Xkvll-annn 1351.36 1.34 1.29 1123 -ExampleXXXVIfh 1.40143 1.43 1.34 1. 24" 1108 0.91 0. 66 ExampleXXXVI 1.43 1.28 0.79 0.21 EXampIeXX'XIII; 1. 50 1.36 1. 34' 1.29 1. 23

EXamp'iesXXXVH -a and XXXVlI-b were successive cuts" in vacuum distillation, with water vapor carrierpdur I in the purification'of di-n-propyl thio-ether of ricmol'eyl" 17 alcohol under Preparation E above; Example XXXVII-a being the condensate from the boiling range of 114-164 C. at the pressure of 1.0 to 0.9 mm.; and Example XXXVII-b the condensate at 164-17l C. at 0.9 to 0.4 mm. .Example XXXIII was the di-n-octyl thio-ether ofricinoleyl alcohol, made as in Preparation E above.

The effect of lubricants, under low temperature conditions, upon the rate of watches, can be illustrated as follows, in which the individual variations of each of ten watches (large, grade D) are stated by values representing the gain (plus sign) or loss (minus sign) in 'seconds during a 5 hour period beginning 3 hours after winding, the values being compared by translation to an rate at plus 75 F.

TABLE XI be formed by using mixtures (e.g. in equal amounts by equivalent weights, with the total amount equivalent in SH or OH content to that of the mercaptan or alcohol in Preparations E, F and G); noting that a usual product may comprise both di-ethers (of alcohols or mercaptans R and R), and both di-mixed ethers (with Ror R at the terminal and R and 'R at the intermediate coupling), along with one or more of the four, mono-ethers;

Comparison of low temperature lubricants I Temperature, F.

Lubricant A commercial low temp. oil 0 +4. 3 -15. 6 (9) 5 3 Stop Stop Stop A commercial low temp. oil L +7. 7(9) 4. 3(9) 28. 8 114. 7(7) -444. 1(7) (2) Example XXXIX 7. 3 14. 4' 25. 6 94. 4 -22[). 0(9) Example XXXVII-b 5- 4(9) -13. 0 27. 0 57. 7(9) 127. 7(9) v In the above table, the numerals in parentheses indicate the number of movements still running'at the end of the respective test: e.g. the entry 523(2)" for lubricant C at 35 F. shows the average of two movements which were still running but having lost 396 and 650 seconds during the 5 hour test. Stop indicates that all ten movements had stopped before the end of the test. It is noteworthy that in someinstances, one or more movements would stop during test-at--one temperature, but would operate to the end of test at a lower temperature. Example XXXIX was di-n-amyl thio-ether of RA prepared in two batches without water vaporvacuum distillation; blended and then subjected to water vapor-vacuum distillation. I

It has been pointed out that the di-n-amyl thio-ether of ricinoleyl alcohol has very desirable lubricating characteristics for low temperature applications. It has also been found that when blended with other materials, it imparts many desirable characteristics to them. For example, when used to replace phenylstearyl alcohol in a presently used synthesized watch oil it increases the average motion of the watches and reduces considerably the effect of changes in relative humidity on the motion of the watch. Another change of importance is a reduction of viscosity without unduly decreasing the surface tension (this latter effect is important because of its relation to retention in jewel bearings which controls .the interval between necessary servicing). A comparison of these lubricants is given in the attached Tables IV to IV-C for two grades of watch movements. Lubricating compositions are included in these tables.

Mixtures of other thio-ethers are likewise satisfactory.

PREPARATION G.OXY-ETHERS FROM IODO COBIPOUNDS The 1,12-diiodooctadecene-9 from Preparation B may also be used in making oxy ethers. An equivalent weight of sodium hydroxide is dissolved in the smallest possible quantity of water, diluting with a primary alcohol such as methanol, and then adding an equivalent weight of the alcohol, such as n-amyl alcohol, which is to provide the other ether group. The dihalide from Preparation B is then added to the alcoholic solution with stirring: and the mixture refluxed for six hours and allowed to cool and settle. The aqueous layer is discarded. The oil layer is diluted with a solvent such as di-butyl ether, washed with 5% sodium hydroxide solution, neutralized, dried and stripped of solvent, and purified by vacuum distillation.

however, when the diiodo component is in defliciency below equivalency by the reaction equations, the essential absence of OH upon infra red study indicates that little mono-ether is present. I

PREPARATION H.RICINOLEYL MONO-THIO-ETHERS The above procedures for the making of 'di-thio-ethers can be employed inmaking the'mono-thioiethers. by employing about one-half the equivalent amount of the radical (in mercaptan form) which is to be joined with the ricinoleyl radical: wherewith the caustic hydroxide acts as before to cause coupling of the radical inthe mercaptan at one halide position in the rieinoleyl' 'compound from Preparation B, and to effect hydrolysis at the other halide position. J

In this preparation, and in Preparation D above, when the quantity of the additive alcohol (or mercaptan) is less than the equivalent to one of the hologen groups of the ricinoleyl compound, and a slight excess of the caustic alkali ispresent, the product contains little or no di-ether, but usually includes re-converted ricinoleyl alcohol (or mercaptan), When the relative quantity is greater, di-ether is formed, and reconverted ricinoleyl alcohol (or mercaptan) is essentially absent.

PREPARATION I.-RICINOLEYL DI-MIXED ETHERS When Preparations D and H are prepared, the ether reaction yields two mono-ethers; and if the quantity of caustic alkali is restricted, the ricinoleyl radical retains the other halogen. These mono-ethers may be converted to mixed di-ethers having differing groups attachedby ether linkage to the ricinoleyl radical, by repeating the operation with an equivalent amount of the second a1- cohol (or mercaptan) to be employed in the ether-ification. Similarly, mixed ethers may be prepared in which one of the additive groups is connected through oxygen and the other is connected through sulfur, by employing first one and then the other of the desired additive radicals in respectively alcohol or mercaptan form.

A present government specification for performance is that the movement will not gain or lose more than 75 seconds at minus 31 degrees F. in 5 hours, compared to its rate at room temperature. Table XI indicates that present materials satisfy such a requirement. In a further series of tests with a group of clocks, which have been run at various low temperatures from time to time over periods of months, with the lubricant of Example XXI (a first batch), it was found that at the beginning some 60% of the clocks remained within the R; but after 16 weeks only 30% passed-this test. Upon continuing the tests at minus 50 degrees F., 75% met the 75 seconds tolerance; and after many'months, 43%

20 containing the ricinoleyl radical combined with radicals selected from the class consisting of hydroxyl, hydrosulfyl, oxy-ether radicals and thio-ether radicals. Preferably, the ricinoleyl radicals are present in the trans according'to this invention is provided by a compoundwerestill within the tolerance at minus 50 degrees F. 5 isomer form to an extent which exhibits at least a one- In a further series of tests upon the lubricant of Exfifth reduction of the infrared band intensity forjthe cor- "ample'XXI (di-n-amyl thio-ether of ricinoleyl alcohol), responding compound containing only the cis isomer. employing this as the sole component (Example XXI), Lubricating compositions may consist of such a lubricant, with added oiliness agent (Example XXXV) and with 'possibly with inclusion of another lubricant such as dih'oth oiliness agent and a surface tension-increasing agent 10 phenyl heneicosanone, phenylstearyl alcohol, etc.: and (Example XXXV-a: being Example XXXV with 0.2% may also comprise an anti-oxidant. ofdodecyl 'piperidine stearate), and with a refined blend The compounds according to this invention consist (Example XXXIX); and noting the number of watches of ethers of the general formula: which stopped (out of the ten movements being investigated; 17 jewels, stem-up position), the results were: CH3(CH2)5?-C=(GH7)7?XR TABLE XII I KR H N0. 0 sto ers in 10 movements 0 rade 616, 16s, 17 a l f pp jewels, stem, 5; 20 wherein at least one of the R and R' radicals 18 selected from a member of the class consisting of straight and branched saturated aliphatic hydrocarbon chains of 1 '1 F. E 1 E 1 E 1 emp ii i 2%? v xii i i -iz xih to 18 carbons, the phenyl radical, the

0 0 0 0 H H H g i g g CHa(CH!)5 -$=(CH2)1 C- 0 1 1 o l 1 a 2 0 H H 10 a 4 1 radical, the

In another test, the movements of Table XII were H H H v H operated for many months with the indicated lubricants; z= gg, xg and were periodically run at the low temperatures in- Y I l 1 dicated, The group was continued on such test as long 7 a as the motion was turn or above. Theywere fitted a i 1 Y radical, and aralkyl hydrocarbon radicals of 7 to 18 carz g g' gi gg s gfi gi ig ifz fig z gg g gsg gzfig bon atoms and the second of the R and R radicals from to accuracy at room temperature prior to the test' but :9 member the class consisting of hydmge-n th? radthe tabulated values have been translated so that each lcals of stralgl-lt and branched Saturated aliphatic by- Watch is considered :at zero-rate at room'temper ature 40 .drogarbon chams 1 to carbon a the phe'nyl (plus 75 degrees F.). "This test is severe as minus radlcal and Many! hydlocarbon rafhcals of 7 to 18 degrees F. is the lowest temperature presently on tentaatoms 1 g and above tive specification by the Armed Forces. The results in m m er 0 e c consls m 0 oxygen an Table XIII show the results forthe ten movements, the S numerical values in the columns under the examples .45 Illustrative of F- i compolmds which f be showing the number of movements which perform with or r f wlth the foregQmg ethelis a change in time rate from the actual room temperaa lubncant, 1S eyl formal To prepare this ture rate of less than seconds over a 5 hour period pompound. grams of dried ncmoleyl alcohol at the stated temperature. Since all four examples 'of 5 grams, of P fi l and 1 gram of p'toluene lubricants had the same base the results of all four have 0 sulfuric acid are mixed in 500 cc. of toluene and heated been indicated in a summation column. The values as rejflux for 2 hours The solvent 13 by found were. distillation, and then the. formal recoveredby distillation under increasing reduced pressure. In one prep- TABLE XIII 55 aration, four cuts were separated as follows: N0. of movements whose change in time is less than 75 v 1 seconds from the room temperature rate over a 5 TABLE, m hour period Gut No. Ralioillngo 1fTressufi'le vagilme weigh; um. ms 7 Number of movements out of 10 within specification 60 ge g g Test Temp., F. 9. 5-5.0 15 10. 7 Example Example Example Example Summa- 5.0 10 8.5 xx xxxv XXXV-fl XXXIX ti'on 5.0 10 10.0 5.0 18 16.9

10 1o 10 1D 40 5 i0 9 10 10 39 E g g is g: The residue was very gummy. Infra-red spectral tests 0 5 e 10 showed strong bands for hydroxyl, ether, and 0:0; 0 3 2 0 5 with unexplained matter represented by terminal CH=CH grouping rather than a cis or trans CH=CH gr ping.

The lubricating effects of the compound per se in watch tests are as follows:

Test A states the average motion of 4 movements of grade E.

Test B states the average motion of 10 movements of grade F in a dry atmosphere; test C states the average motion of the same in a Wet atmosphere; test D states the humidity eflect as the difference of the values for tests B and C.

Test E states the average motion of 10 movements of grade G in a dry atmosphere; test F states the average motion of the same in a wet atmosphere; test G states the humidity effect as the difference of the values for tests E and F.

Test H states the average motion of the stated number of movements of grade B at room temperature; tests I, J, K, L are of the same, respectively at F., minus 25 F., minus 35 F., and minus 50 F. In Test I, (1) indicates that one movement stopped.

Blends of this compound with the above ethers form satisfactory lubricants at the 50550 ratios and have essentially the behavior of the ether itself, and operate like the blends of the ethers with diphenylheneicosanone referred to in connection with Tables IV to IV-C above.

The foregoing statements of practice are illustrative; and it will be understood that the invention may be practiced in other ways, within the scope of the appended claims.

What is claimed is:

l. A lubricant consisting of di-n-amyl t-hio-ether of ricinoleyl alcohol.

2. A lubricant consisting of di-n-amyl thio-ether of ricinoleyl alcohol, and characterized by having ricinoleyl radicals in trans isomer form in an amount represented by a dip of at least one-fift-h in the standard infra-red graph.

3. A lubricant consisting of di-phenylamyl thio-ether of ricinoleyl alcohol.

4. The method of preparing a lubricant, which comprises subjecting ricinoleyl alcohol to an ether-forming reaction and thereby coupling the ricinoleyl radical through an element selected from the group consisting of oxygen and sulfur to another radical selected from the group consisting of hydrocarbon radicals of l to 18 carbon atoms, terminating the reaction before completion, and recovering a product containing ricinoleyl alcohol and with at least five percent of at least one ether of ricinoleyl alcohol selected from the group consisting of the oxy and thio ethers thereof.

5. A lubricant made as in claim 4.

6. A lubricant consisting of ricinoleyl alcohol and an ether, said ether constituting at least 5 percent by weight of the mixture of alcohol and ether, said ether being selected from the compounds of the general formula:

wherein at least one of the R and R radicals is selected from a member of the class consisting .of straight and branched saturated aliphatic hydrocarbon chains of 1 to 18 carbons, the phenyl radical, the

radical, and aralkyl hydrocarbon radicals of 7 to 18 carbon atoms and the second of the R and R radicals from a member of the class consisting of hydrogen, the radicals of straight and branched saturated aliphatic hydrocarbon chains of l to 18 carbon atoms, the phenyl radical, and aralkyl hydrocarbon radicals of 7 to 18 carbon atoms, and wherein X and X of the above formulas is a member of the class consisting of oxygen and sulfur.

7. A lubricant consisting of an ether compound of the general formula:

wherein at least one of the R and R radicals is selected from a member of the class consisting of straight and branched saturated aliphatic hydrocarbon chains of 1 to 18 carbons, the phenyl radical, the

radical, and aralkyl hydrocarbon radicals of 7 to 18 carbon atoms and the second of the R and R radicals from a member of the class consisting of hydrogen, the radicals of straight and branched saturated aliphatic hydrocarbon chains of 1 to 18 carbon atoms, the phenyl radical, and aralkyl hydrocarbon radicals of 7 to 18 carbon atoms, and wherein X and X of the above formulas is a member of the class consisting of oxygen and sulfur.

8. A lubricant consisting of a di-ether of the general formula set out in claim 7.

9. A lubricant consisting of a mono-ether of the general formula set out in claim 7.

10. A lubricant consisting of a mixed ether of the general formula set out in claim 7, in which the R and R radicals are different.

11. A lubricant consisting of a mixture of different ethers each of which has the general formula set out in claim 7.

12. A lubricant consisting of an ether of the general formula set out in claim 7, in which one of the radicals R and R' is an aralkyl hydrocarbon radical of 7 to 18 carbon atoms.

13. A lubricant consisting of an ether of the general formula set out in claim 7, in which one of the radicals R and R is a hydrocarbon radical of l to 12} carbon atoms.

14. A lubricant consisting of a mixture of 20 to 50 parts by weight of an ether, and 80 to 50 parts by'weight of 'diphenylhen'eicosanone, totalling 100 parts by Weight, said ether being of the general formula set out in claim 7.

15. A lubricant consisting of an ether with 0.1 to 1.5 percent by Weight of an antioxidant, said ether being of the general formula set out in claim 7.

16. A'lubricant consisting of an ether of the general formula set out in claim 7, in which the trans-isomer form is present in an amount represented by a dipo at least one-fifth in the standard infra red graph. 7

17. A lubricant consisting of an ether of the general formula set out in claim 7, in which X and X are oxygen atoms. 1

18. A lubricant consisting of an ether of the general formula set out in claim 7, in which X and Xfi'are sulfur atoms.

19. ,The method of lubrication between two relatively movable bearing surfaces, which comprises applying to at least one of said surfaces an; ether having the general formula set out in claim 7, and maintaining a film of said ether between said'surfaces during relative movements thereof.

20. The method as in claim 19, in which one of said radicals R and R is an aralkyl hydrocarbon radical of 7 to 18 carbon atoms including an aryl hydrocarbon terminal group.

References Cited in the file of this patent UNITED STATES PATENTS 2,094,611 Lazier Oct. 5, 1937 2,200,298 Robinson May 14, 1940 2,355,616 Barker Aug. 15, 1944 2,491,533 Swern Dec. 20, 1949 2,552,510 Barker May 15, 1951 OTHER REFERENCES J. Chem. Soc. (London), 1950, pages 3187 to 3189.

Claims

6. A LUBRICANT CONSISTING OF RICINOLEYL ALCOHOL AND AN ETHER, SAID ETHER CONSTITUTING AT LEAST 5 PERCENT BY WEIGHT OF THE MIXTURE OF ALCOHOL AND ETHER, SAID ETHER BEING SELECTED FROM THE COMPOUNDS OF THE GENERAL FORMULA,
7. A LUBRICANT CONSISTING OF AN ETHER COMPOUND OF THE GENERAL FORMULA:
16. A LUBRICANT CONSISTING OF AN ETHER OF THE GENERAL FORMULA SET OUT IN CLAIM 7, IN WHICH THE TRANS-ISOMER FORM IS PRESENT IN AN AMOUNT REPRESETED BY A DIP OF AT LEAST ONE-FIFTH IN THE STANDARD INFRA-RED GRAPH.