US2018758A - Lubricating composition and process for making the same - Google Patents

Description

Patented Oct. 29, 1935 PATENV FFICE LUBRICATING COMPOSITION AND PROCESS 1 FOR MAKING THE S A Carleton Ellis, Montclair, N. a, assignor to Standard Oil Development Company No Drawing. Application May a, 1932 Serial No. 609,038

l3 The present invention relates to improved lubricating oils particularly those of high lubricating value of the petroleum type, and relates especially My invention will be fully understood from the following description of the product and its method of manufacture.

Various addition agents have been incorporated from time to time in lubricating oils for the purpose of increasing their load bearing capacity or for other similar reasons. I have found, how.-

5 ever, that many of these agents while extremely efiective for some particular combination of hearing metals are not equally desirable for other types of bearing combinations. The present invention is concerned with a class of substances :0 possessing a property of notable significance, l. e., that of imparting to the lubricant a higher degree of film strength in substantially all types of bearing combinations or, if in certain bearing metal combinations it is not substantially raised, at least 5 it may be said that the presence of these substances does not lower the film strength for such bearing'metal combinations, while other properties obtain as hereinafter disclosed. By this means the film strength generally is perceptibly 30 increased permitting the use of smaller bearing surfaces and enabling the journals or other types of bearings to be operated under more severe conditions of load, speed and the like. The compounds of this sort which are disclosed below thus 5 favorably aifect the state of tension of the lubricating film and may be termed tensionizers.

Another valuable property of many of the materials disclosed below is'Ithat they act as pour inhibitors. Lubricatingpils produced from crude oil, hydrogenated hydrocarbon oils and the like contain waxy constituents in such amounts as to cause the oil to congeal or solidify at relatively high temperatures within the range in which such oils could otherwise be used as lubricants. Oils from paramn or mixed base crudes in many cases solidify at 50 or even 75 F. for the heavier cuts and the lighter distillates often solidify as high as 30 or'40 F.

50 It is the practicein modern refineries to re centrifugal means, but all of those methods require expensive refrigeration.

0n the other hand, the invention is likewise applicable to oils which have not been dewaxed or oils to which, for one reason or another, paraflln Y 5 wax, ceresin wax, petrolatum and the like, has been added.

As stated above many of the substances disclosed below act not only in the capacity oftensionizers but likewise exert a pour inhibiting infiuence. Therefore, according to the preferred form of my invention I utilize compounds which are capable of functioning in the dual role of pour depressant and tensionizer and which may be designated as pour depressant tensionizers or tensioniaing pour depressants.

The materials which form the basis of my in= vention are nitrogen-containing and of the class formed by the reaction of hydromv amines, particularly the alkylolamines such as methanol-,

ethanol--, propanol-, butanol and the higher hydroxy amines with an organic acid, specifically the esters f'orme'd thereby which are adequately soluble in petroleum lubricating oils to function in the manner described above. I do not wish to exclude, however, as pour depressants and/or tensionizers the salts of the amines such as formed by the simple addition of the acid to the amine and which reaction is characterized by combination without elimination of water; preferably, the products which fall within certain specific confines of the present invention are the true esters formed by the reaction of acids with hydroxy amines and characterized by the elimination of water. In such cases amine salts, if desired, may 3 be present, or the product may at the same time a be an amine salt and amino ester.

The said products may be obtained in the same manner in which true esters are formed, for example, by mixing the alcoholic material, that is 40 to say, the hydroxy amine in this instance, with the organic acid and efiecting the esterification,

for example, in the presence of sulphuric acid or other inorganic acids in the ordinary, well-known manner, or the esterification may be accomplished by heating the reactants at a temperature of 212 F. or somewhat higher in the absence of mineral acids. Those methods are apt to produce a certain amount of the salt as well as the ester and if it is desired to produce only the ester, 3 mols of the acyl chloride may be heated with, for example, 1 mol of the trihydroxy amine in the presence of a basic material such as pyrldine. In such case the hydrochloride of pyridine is formed, and the esterof the hydroxy amine and themeviemiyuxidizedmmnganmeandwbaitresinatemberimneimmmteandthem, mixtmeseimesemaw'iaism'otm-Wate assteaiieeleimbehmiem'emeiemaybemed asweiiastheheavierunsammtedaeidsermixturesoithesevmieusmafieriais.

Theseestemmagybedispemedthmughthewax eontainingbyflmmflmneiibymeanswasohm asforexampiealeahei,benzme,naphiha,eram othersimiiarlightsnlveutcambieddimhnmg the esters and mixing wifli'the waxy uiis. m solution of the esberiseddedte the wax-mininingoilwhiehisthenthurwgmyaaitatedmmrm a homogeneous name after which the mperatureofthemixhiremayberaimdwsufli adegreeastobm'iofltheiw-bniiingsulvent withuutdeeempesingfliehmviereii. Emeferred the seiventmbeeminated ahogemer. andizhe-estermmedwiththeoilmetemhbby heatingtoabnntmr'. mthemtermybe addedtoapertienoitheeiiimisfmmingemmcenhateswhieheanbeusedadvmmgemiswes additions tothe oil stuck in suitable prelim-him 'lheestermagbeaddedtotheeflmmdesiredpmpm'timierexampmbeiowmwemt 01'5 per cent. 'Ihe-difiemtmhstanees vary somewhat in then new mime and/m mmsienizing puwemandwuseqmenmwmbeused insomewhat difierent; often-mm lto2pereentismemustdesh'ame. Eenemliyan 011mm 11mm fur- W ingstrength; furmflmmemim pominhibiterisusedtiiemaximmmpem-xeduetionisnetebteineiamatfliesameme iftoogrmtaquamtyismdquamesufftheefl maybealteredtoadmundeflmhiefurme besaiiithatthem m misneariyaiwayswifliintiiemngeflmmahomfllmmper cantandthemeperquanfltyofesiamquimd furapartieuiaruilcanbemdmdetermimedhy test.

-Asanexampleufflieaeflmufsiihsmneesm aemrdingtomyinvmtimflieimwmgmbe takenasillusla'afive. lhetmsimiizingpourinhibitorismadeinthemnnerdmefihedabcwe fromti'iethanoiamineandamixlm'em'aeidsebtainedbytheuxidafimofmmmbybbwingwiti airattempemmresutahmatwm 300F. Thetrieihamflammeandtmemdsam usedinfliemopertimufletflnemmemeheuf Gravity, 30.6"5. P. I. I

Viscosity (Subult) at PL, seconds. Viscosity (Saybolt) at 210 E, 45 seconds. Pour, 31! F.

(150101 (Robinson), 10%. 10

when the mopnrtion of m added was 05 pereentitwasfoundthatthesolidifieafinnpoint oftheoil,30F.,was1edueedtol5F. Whmthe pour inhibitor was added in the proportion of aboutzpereenttothesamedLitspour mintfi wasreducedto-5F. Inboflicasesthedher above mentioned properties of the oil were substantiallyunehanmd. Theloadbearingcapaeilw oftheblendedoiiwastestedinm'speettovarimis difl'erent beuripg by the Mongeyfll methodasdeseribedintheNafionaiPetmlmm News, November 11, 1931, page 47. Thefolhwing bearingeombinafionswereused:

Steeltobmnze.

Steeltoaluminum.

SteeitoBabbitt.

Steeltoeastiron.

Castimnmeestiron.

Castimntoalumimnn.

steeltosbeel. lnailotthmeeasestheblendedoflgaveexeellmtserviee.

While,ashasbeenindicated.diifmentmetal bearingcombinationsaiforddifieringdegresof serviee,itmaybenotedthatinthecaseofsteel tnahnninum,castirontoalmninmnandsteel tosteeLtheoilwithtensionizerafuremidgave emaderably better service than the untreated ails. Inflsinglargeramnuntsthan2peremt thepourinhihitmgpowerwassomewhatdim-M mished. ltispossihiehowevertoestahlishsimulmeouslyina'givmoil adequate mpurtionsuftheeefiveamino compound.

Thepourinhibitorerpourdeprmntandlorfi tensinnizermeybeprepaxedalsosimpiybyheazmgtheamineandurganicaeidtogetherwihhmit suiphm'ieaeidorotherstmngaeidcataiystof wzm'ificatiei. Thisstepifdesiredmaybeearfiedoutin'flieoilitselforinaportionuithenl Inthelattercase-awneentratecanbemepamd martothetindieatedabove. Oilwhiehisat a high temperature from some other mewieus eperationmay receive additions of the componentsotthe pour depressant and/01' tensinnim, musmtivelytheaeidsfromuxidizedpammwax and triethanoiamine, reaction taking place in tmlmtvehieieandderivingthepmduetinavery eenvemientmanner.

Ontheotherhandthepourdemmterten- 5o simiaermamiurexampleintheabseneeofan m'ldiinent suehasthat mentioned above,beur- Mmeentratedifneeessarytoahigherdegme e5 pofieney by.treatment with appropriate solvmtsizoseparateaimreizmveinmztiveorllesseefive eomponeats.

ltshouldbe'mentionedaisuthatwithhydtm amiueseontainingtwourmorehydmxylgmu s m the molecule (polyhydr xy amines), sxeh as memolamimimayalsomakeestersbymixingtiieamineandfattyaeidsinfhestoichinmetziem'oporfiunsoflpartotaminetolmnoi aeiiorleartofaminetoiipartsofaeiiinsteed eithemfieoflpmtofamineto3partsetaeid esgivmintheabove-esample. Furthemm flcrude acids obtained by the oxidation of paramn wax may be fractionated, for example by means of vacuum distillation and a low boiling or higher. boiling fraction used, ranging from liquid or soft acid material to hard wax acids, as desired. In general the compounds comprised herein preferably are derived from higher fatty acids and the like including those the moleculeof which contains 10 carbon atoms and over. Wax acids embrace a wide range of acids as denoted by the number of carbon atoms, whereas the acids derived from animal and vegetable fats possess carbon atoms from say 12 to 22 in number, the acids commonly available being those of 12, 16, and 18 carbon atoms. These various fatty acids are comprised under the term higher fatty acids as used in the foregoing.

In addition' to the foregoing additions to lubricating oils in accordance with the preferred form of my invention I also may add anti-oxidants such as certain bodies containing phenolic groups. Certain amino compounds also act as anti-oxidants and the amino compounds included in the present invention serve for this purpose to the extent that such function is available, but others may be added for additional effect. The addition of these substances may be made to an oil which has been used so as to become slightly oxidized and is susceptible to further oxidation accompanied by sludge formation. These materials not only reduce the susceptibility of the oil to further oxidation but also modify the oil by imparting to it a greater load bearing capacity and pour reducing properties as indicated above. My process serves as a valuable aid in the recovery of used lubricating oils. After considerable heavy service a lubricating oil develops acidity and sludge. The sludge may be removed in a variety of different ways, for example by filtration which also removes metal particles and dirt; sludgy constituents which are not entirely removed by filtration can be removed by adsorptive means such as by the use of fuller's earth and the like. These methods will leave the oil. however, inan acid condition. If desired I may add my alkylolamines directly to this oil in the preferred proportions and the oil may be heated at an elevated temperature so as to cause combinations between the acids of the oil and these added substances. In this way the alkylqlamines serve as purifying agents for the oil in eliminatdng acidic bodies and at the same time converting them into substances which give additional valuable properties to the oil.

My oils, whether originally'produced by the addition of-the alkylamine esters, acids or the like to fresh hydrocarbon oils, or whether present in the oil due to recovery of the used lubricating oil, find a valuable application as breaking-in" out. For this purpose the. oil is used in the ordinary manner for the first 500 to 1000 miles of operation in a new car. As is well known the bearings of the car are not completely worn in and above and when such an oil is used it is proposed to operate a new car from the high speeds and to disregard ing the breaking-in" period.

In like manner thesepour depressants may be incorporated in greases or gear oil such as transrt at relatively e usual care durmission grease to aid in reducing the tendency. to channeling and the like. 7

In the above description I have mentioned generally all types of combinations of the alkylolamines with fatty or other organic. acids. While. all of these materials bring about improvements in lubricating qualities, I have observed that the true esters are more soluble and more desirable than either the salts or the ester salts, that is to say, the materials which are both esters and 10 salts. For this reason I have a marked preference for the esters alone; Not only are they superior in respect to tensionizing influences but also their pour reducing properties are .markedly superior. Y

My invention is not to be limited by any theory 01'- the mechanism of pour reduction or of "breaking-in" nor to the particular substances described for purposes of illustration, but only to the following claims in which I wish to claim all novelty 20.

.the organic acid hasfrom 10 to 22 carbon atoms.

4. An oil according to claim 2 in'which a polyalkylolamine is used. 5. A lubricating 011 comprising a mineral oil and a minor quantity'of an ester produced by the reaction of an alkylolamine and. an organic acid.

6. A mineral oil according to claim 5 in which the ester is produced from a polyalkylolamine.

7. An improved lubricating oil comprising a 40 viscous hydrocarbon oil containing a minor proportion of an ester of a trialkylolamine and an organic acid of at least 10 carbon'atoms.

8,. An improved lubricating oil comprising a viscous hydrocarbon oil containing an ester produced by the reaction of triethanolamine and an organic acid of at least 10 carbonatoms, said ester being in. tensionizing and pour inhibiting proportions.

9. An improved lubricating oil comprising a viscous waxy oil and an organic product of the reaction of an organic acid having at least 10 carbon atoms with an alkylol group of a poly- -alkylolamine in tensionizing and pour reducing proportions.

10. An improved lubricating oil comprising a viscous hydrocarbon oil containing waxy constituents,-and an ester formed by the reaction of a polyalkylolamine and an organic acid containing at least 10 carbon atoms, said ester being in tensionizing and pour reducing proportions.

11. Lubricating oil composition comprising a viscous waxy oil containing in a dissolved state an organic product of the reaction .of an alkylolamine with an organic acid having at least 10 65.

carbon atoms in pour reducing proportions. 12. Lubricating oil composition comprising a viscous waxy hydrocarbon 011 containing in a.

dissolved state an organic product of the reaction of a polyalkylolamine with a fatty acid of at least ten carbon atoms in a. ur reducing proportion of not more-than abou two per cent.

13. A mineral oil composition according to claim '5 in which said'organic.acid is a fatty acid.

.caaan'rou ELLIS. to