US2095538A

US2095538A - Lubricating oil composition

Info

Publication number: US2095538A
Application number: US142624A
Authority: US
Inventors: Arnold C Vobach
Original assignee: Sinclair Refining Co
Current assignee: Sinclair Refining Co
Priority date: 1937-05-14
Filing date: 1937-05-14
Publication date: 1937-10-12
Anticipated expiration: 1954-10-12

Description

u trm ii lubricatin oilitsel J for exan iple applicat o 1s inf'paftfa cont nat n o 2,081 075 v; s granted May 18,1931

' i Calcium phenvl s'tearat fical Societyj149; 11 031:10'6,*(19:27),' and 52; 1172- M11174 1930). Ca1ciumstearate. has long been Fused inwcompounded petroleum lubricating i i greases. This invention relates toimprovements F25 ins, liquid petroleum "lubrica'nts 'afs j disting'uislried fromsolid or semiesolid petroleum greases: 'I'heterrnwffpetroleum lupricating soils is intended to refer ,-herein upricatipg, oils oi petroleum Origin having vis ositieseupwardscof 50570 see- Ttio n nes 11a imposed increasingburdens upon oils-use or. their lubrication, particfl Mfularlj with'respectfto operating temperatures 3 t and pressuresa- At present, the Dieselitype of engine probably represents ,extreme L requirethe imposition of f severefburdens upon alonevi 1 termined," :inlarge; measure; lbyiits, thermal eta,-

* yrunctionic asa ulo riee t tiitfieihigntempe atures and i high pressures encountered; One

ftw neasurefiof thermal stability is resistance to:

oxidation, andthe consequent" tefidencyto form t inal instability is determined notonly by the =;extent,of oxidation or decomposition but alsoby ,the ch zglrficitea'rv of the products" of Isuch decomposidf deposits of suchprod'uets. improved lubricating oil; compositions of my rivenltionha e, addit ionfto the' lubricat ing flproperties of the petroleum 011$ "which they n it Ql zgosases v in J v 3 LWRI A INGEO M QS II Amara-cavemen, Whiting, 1511;; assign toSin- 1.3,; clairt'RefiningflCompany, New York, N, Y., :a

a corporation of -Maine 1 ratvingl gApplicationMaj 14,1937, Se rial No. 142,624 l i a b ow s: C 81-9113 1 r are com ounded; a thigh solventllcapacit v have been described thechemicalliteraturei zofse e forexample j Journallofithe American Chem Lrrients n both 0: these respects, but it is, not

i :the l uhricating oil used. LThe:usefulfoperatingi lite of a ubricating "oil, insu ch service, is deabilitycjandby; its physical capacity tocontinue sludge,- but in another aspect ,theeffect of 'therand, by thje' extent and location,

sludge; of the character formed Qbyf; oxidation of petroleum; lubricating oils and, perhapsip 6Y9? greatenimportance,"the properties of render g deposits of sludge and fearbo'n. withing the en gine soft and friablerather than hardjfland co: herentarid of: disintegrating and removingsuch deposits 'asan sincident of @the normal operation of the engine} In .this aspectQtheJribricating oil compositions of my invention render .the engines Vinwhichthey are usedlself-cleaning to an im-i portant extent. r

In theDiesel type1ofEeneinel 'iorsexample, the

high temperatureshtowliichcthe. lubricating goil i is subjected, particularly at ithetop of the stroke," frequently causesdeposition.1of .sludge ;;and carloonizationin' the groove. for and behindcone or; more of the piston rings; 1 Using parafjnic type pronouncedvvith respect to the uppermost ring; u'sing naphthenic typek lubricating: (oil they are usuallynrnore pronounced with respect to the lower rings. consequent-stickingof'the rings rapidly deprivesqthe piston and cylinder wall of proper;lubrication.inducing-excessive :Wear; and; frequently, scoring of the cylinder ulwalL The formation or such carbon I deposits, ,hard enough and coherent ienough, to" involve sticking lubricatingoils such difficulties are usually more of the rings, is materially: retarded, if i not avoid Compositions or my invention, and in this aspect the self-cleaning properties 'of i the lubricating oil compositions of my invention; with respectqto the engirie, makamere changev of oi l.'a sub;

stitute, economical with respect Zbothtoloss oi service time and cost, forcmany otherwise necessary cleaning and repair jobs; it Calcium phenyl stearate, or mixturesincluding calcium phenyl 'stearate and calcimn stearate, for compounding the improved lubricating :oil

compositions of my invention can-fbe: produced asfollowsz l part (parts byweight) of pulverulent anhydrous aluminum chloride is stirred into 4 parts of commercialbenzol boiling below "C -thisstirringbeing effected at ,atmos i pheric pressure and at ordinary] temperature I u 2 parts of oleic acid; commercial redv oil containing as a' minimum' 96% free fatty-acidv as oleic acid a and having a, maximum-xcloud test-of 45 -;;F.,Vis

added to thismixture With stirring,itheaddition being made over aperiod of about an hours, This reaction is'carried out at atmosphericpressure; [and is started at ordinary;temperature. ;;;The

temperature rise incident to the reactionis limited so that the maximum temperature approxi mates 180 F., the temperature being controlled either by cooling or by regulating the rate of addition of the oleic acid. The reaction mixture is maintained at a temperature 01 140-180 F. tor 6 or "Ihours. For at least the last half hour of this period the reaction mixture is held at 180 F. to insure completion of the reactionand to assist in stripping hydrochloric acid from'the' reaction mixture. The reaction product, a pasty liquid, is then added to about /4 to of its volume of aqueous hydrochloric acid, 15%20% HCl, at ordinary temperature. The ensuing reaction brings the temperature, for example, to about 170 F. This reaction mixture is thoroughly stirred and the aqueous acid solution is then separated from the oily product of the reaction, by decantation for example. This separated oily product is thoroughly washed with water, advantageously with hot water, in two successive stages with about /2 of its volume of hot water in each stage for example. This wash: ing should in any event be continued until a qualitative'test for aluminum-in the wash water is negative. After this washing, the, reaction product is a thin, oily, dark green. liquid, It is allowed'to stand to settle outv any remaining water. Benzol1-is stripped .rrom this oily. liquid by vacuum-of 4 millimeters of mercury absolute pressure, a first cut 'of about 25% is taken all up to the point at whichthe temperature of the liquid in the still reaches 466 F. and a second cut of about 53% is taken of! as the temperature of the liquid in the still rises from 466 to 590 F. The second of these two'distillate fractions can be saponified with. lime" to produce the material to which I refer .as calcium phenyl stearate, or these two distillate fractions can be combined and together saponifled with lime to produce a mixture of this calcium phenyl stearate and calcium stearate. For example, 4 parts of the secondfraction, or 4 parts of the first and second fractions together, diluted with an equal weight of petroleum naphtha boiling between about 200 F. and 322 F., can be saponified with about 1 part of hydrated lime, added in 2 or 3 portions with thorough stirring. The temperature of the reaction mixture rises to about 160 F., for example, and then by external heating with reflux condensation of the naphtha diluent is maintained at about 190 F. until the saponification is complete. This reaction mixture is further diluted with about twice its volume of the same petroleum naphtha and unreacted lime is seperated by centrifuging. Benzol may be used as a diluent, in both instances, inplace of naphtha. After separation of unreacted lime, the diluent is' distilled off, limiting the maximum temperature of the liquid in the still to about 375 F.,

carryingout the distillation under a vacuum if necessary to keep within this temperature limitation. This undistilled product is used as calabout 20%.

accuse cium phenyl stearate. or as a mixture of calcium phenyl stearate and calcium stearate it the first distillate fraction as well as the second is saponified, in compounding the improved lubricating oil compositions of my invention. Instead of saponifying the second distillate fraction, or the first and second distillate fractions as just described, a somewhat larger excess of lime may be used, 3 parts ofthe distillate fraction or fractions to 1 part of hydrated lime for example without dilution until the saponification is completed and the reaction mixture then diluted prior to separation of unreacted lime, the saponification being otherwise carried out as just described. Or, it is also possible to use that amount of hydrated lime just necessary to complete the saponiflcation, and to eflect the saponification without dilution either during the saponiflcation or following the saponiflcation.

In referring to calcium phenyl stearate herein, I refer to the calcium compound constituting the major component oi! the saponification of the second distillate traction irom, the condensation or 'oelic acid with benzol as described in the preceding paragraph although, of course, I intend to refer by this'term to this same material by whatever process it may be made. I believe this calcium phenylstearate to be the cal cium salt of 9 or 10 phenyl stearic acid, but'I do not predicate my invention upon this identification of the compound as a matter o! terminology. The refractive indiceafacid numbers, saponification numbers and iodine numbers of the totalreaction product of the oleic acid-benzol condensation, oi the first and second distillate fractions and of the residual fraction produced as described in the preceding paragraph, as de termined in one instance, were as follows:

Total reaction First cut 83? Residue product 1 Rairactive index at 20 C 1. 4875 1. 4610 '1. 4880 1. 5171 Acid number 166 103 155 127. 6 Saponitication number-.. 168.1 192. 6 160 101. 7 Iodine number l0 1. 90' 4. 0B 23. 6

The calcium phenyl stearate. or the mixture including calcium phenyl stearate and calcium stearate, produced as above described, is a viscous jelly-like material which is 'difilcult to handle and adequately disperse'through a lubricating oil. When addedv to a lubricating oilin substantial proportions it tends abnormally toincrease'the viscosity.

I have found that when a small amount of normally solid stearic acid is added to the viscous jelly-like calcium phenyl stearate, or calcium phenyl stearate mixture, the gel immediately thins out and can be convenientlyhandled and easily dispersed in the lubricating oil. Further, the presence of a small amount or free stearic acid reduces any tendency of the calcium phenyl stearatemixture abnormally to increase the viscosity of the oilto which it is added, and may'with some oils improve the viscosity index. Palmitic acidand mixtures of stearic and palmitic acids also are useful in this connection.

I have found that the addition 01 7-8% of the free acid to the calcium phenyl stearate mixture is particularly advantageous although it may be usefully included in proportions up to In compounding the improved lubrieating oil compositions of myinvention with the Q portion of theffree acid, advantageously 7-8%, is added, to the calcium phenyl stearate or the mixture including calcium phenylistearate and] then added to the lubricating'oil in proportions ranging from about,0.5 up to about, 2.0% or 2.5% V

jphenyl stearate mixturefwhile theliatter isat Qan elevated temperatureb is' advantageous to carry outthe jsaponification of the phenyl stearic acid inadmix'ture with a petroleumoil, such as a part of the petroleum stearate, is eventually to beyblended; For. examplc', 10 to ofithepdistillatefractionor stcck andthe saponification with lime carried materjiali. Howevenlwhenasmall amount of free i amount of calcium phenylv stearatel or [calcium added," the gel immediately thins; out {so that, it can ,be conveniently handled and readily dispersed through such an additional quantity of the petroleum.lubricating oilas'may be required ;to reducethe concentration of thecalcium phenyl stearatemixture to anydesiredvalueli i f Alcompositionconsisting:essentiallyjof a South Texas pale oil, havinga viscosity of 500 seconds up to 700 Franc 90% up to 900511., approxiof calcium phenyl stearate andcalcium stearate densation of oleic acid with benzol as previously f; 503mm leavestheengine free from sludge or carbon exceptior a slight discoloration.offthepiston justfabovethe lowermost compression ring and ladecuately j'lubricates the moving parts of the: i

engine My invention is also useful in lubricatusual] petroleum lubricating oils, a minor rocalciumsstearate, and the composite mixture is;

, i In the preparation of, thejjimp roved lubricat ing oil-compositions of my invention it sometimes lubricatingoilwith which the calcium phenyl fractions prepared as, before described, may be blended: with such akpetroleum lubricating oil out iiisuchgblendi'lhg concentrated blend of petroleumflubricating oils and calcium: phenyl stearateg orca1cium"phenyl stearate mixture, hereby producedis likewise a viscousjelly-like vention.

stearic acid; for example 758% based on the i i v i i phenyl stearate and stearic acid. lphenylwstearate'mixture present in thej bleiid, is

i a 100? F. saybolt Universal, and boiling 10% ately, 1 /3%byweight on the oil ofa mixture produced by saponifying together the first and second distillate fractions from the vacuumudistillation of the! reactionjmixture from the con-z described, and approximately 108% of stearic acid is particularlyqadvantageous, In service in a Diesel type engine, this lubricating oil composipalmitic acid.

ying .oil compositions embodying lubricating oil from paraflin'base crudes, asphaltic base crudes and, mixed base crudes.

While I predicate my invention upon the re- ,sults obtained in its practical application and not upon any hypothesis, it now appears that the calcium soaps of aromatic stearic acids, gen erally, are useful for the purposes of my invention. Other aromatic stear'icacids, tolyl stearic acid, xylyl stearic acid, naphthyl stearic acid and,

anthracyl stearic acid for example, may be made by methods generally similar to the method above described for the production of phenyl stearic acid, and may'similarly be saponifiedwith lime to produce the corresponding calcium soaps.

The presence of the aromatic groupin the calcium soap seems to, promote the solvent capacity, H

of the lubricating oil composition with respect .to sludge, and may assist in improving any thermal stability. Soaps of these organic acids containing an aromatic group also have the propmating the end, point, .or carboniz'ation temperature, of the petroleum lubricating oils used in the lubricating oil compositions of my in- Iclaimzl i J1. Aliquid lubricating oil, composition com prising a petroleum lubricatingyoil, calcium 2. A liquid lubricating oil composition comprising a "petroleum lubricating oil, calcium phenyl stearate and a fatty acidof the class consistingcfstearic acid and palmitic acid.

3.Aj]liquid lubricating oil composition comprising as petroleum lubricating oil, calcium phenylqstearateand a mixture of stearic acid,

anq palmitic acid.

A liquid lubricating oil composition cornprising-a petroleum lubricating oil, calcium phenyllstearate, calcium stearate and stearic 5 A liquid lubricatingoil compositioncom prising a petroleum lubricatingoil, calcium phenyl stearate, calcium stearate and a fatty 6; A, liquid lubricating oil composition com prising a petroleum lubricating oil, a calcium soap of an aromatic stearic acid and stearic acid.

7. A liquid lubricating oil composition comprising a petroleum lubricating oil, a calcium soap of an'aromatic stearic acid and a fatty acid of the class consisting of stearic acid and ARNOLD C. VOBACH.