US2652363A - Grease compositions - Google Patents

Description

Patented Sept. 15, 1953 UNITED STATES PATENT OFFICE GREASE COMPOSITIONS Harold A. Woods and Loren C. Bollinger, Martinez, Calif., assignors to Shell Development Company, Emeryvillc, Calif., a corporation of Delaware No Drawing. Application December 29, 1951, Serial No. 264,231

11 Claims. 1

This invention relates to special grease compositions. More particularly it is concerned with greases resistant to'the solvent action of water and of light hydrocarbons such as gasoline.

In the lubrication of metal connections for pipe lines and flexible metallic hoses and the like, difficulties are encountered when the fluid carried by the pipe line dissolves the lubricant away from the connections. This becomes a matter of great concern in military applications and especially for such purposes as fuel transfer between planes during flight. Greases comprising ordinary metallic soaps and mineral lubricating oils are, much too gasoline sensitive to be used for such purposes. On the other hand, it is undesirable to have a grease which is entirely insoluble in gasoline or water since between periods of use the grease forms hard metallic residues which plug the connections and cause other difficulties of operation. A number of greases have been proposed for use on apparatus such as valve connections and the like wherein the grease is composed substantially entirely of gasoline-resistant ingredients. Hence, the art has proposed the use of greases which are known to be too sensitive to the action of gasoline for critical uses such as inflight transmission of fuel and, on the other hand, has proposed lubricants which are substantially insoluble in both water and gasoline.

It is an object of the present invention to provide greases which are resistant to washing away by the action of gasoline or water but which are not entirely insoluble therein. It is another object of this invention to provide greases for temporary use and which do not cause the formation of hard metallic residues. Other objects will become apparent during the following discussion.

Now, in accordance with the present invention, it has been found that gasoline and water resistant greases may be formed by utilizing as the major liquid components a mixture of a water soluble polyoxyalkylene fluid and a partial ester of a polyhydric alcohol having less than six carbon atoms with a higher fatty acid. Additionally, it has been determined that other advantages are gained by the presence of a combination of an aromatic amine and a substituted oxazoline, all as more particularly described hereinafter. More specifically a grease having optimum propertie comprises a gelling amount of an amine soap of a higher fatty acid. The latter type of soap is preferably dispersed in a partial ester of a higher hydroxy fatty acid mixed with a water soluble polyoxyalkylene compound. The chief advantages gained by the use of this type of composition comprise the essentially gasoline and water resistant character of the entire composition while, at the same time, the amine soap leaves a soft residue which tends to be flushed away to a large extent during use in the transmission of gasoline, or other light hydrocarbon, thus leaving a film on the connecting parts of the mixture of gasoline resistant lubricants, namely, the partial ester and the polyoxyalkylene fluid. Hence, this type of composition comprises an advance over the two types of greases already proposed, namely, those which are sensitive in both the fiuid and gelling components to the solvent action of gasoline and the opposite type of composition which is entirely insoluble in light hydrocarbons and water.

The soaps The soaps with which the present invention is concerned comprise particularly the hydroxyalkylarnine soaps of higher fatty acids. Preferably, these fatty acids have at least 12 carbon atoms and optimum results are obtained when the fatty acid has between 16 and 20 carbon atoms. While satisfactory results may be obtained with ordinary saturated fatty acids, the best solubility relationships are gained by the use of unsaturated fatty acids and, more especially, by employing unsaturated hydroxy fatty acids. Suitable materials include the following: capric acid, undecylic acid, lauric acid, myristic acid, stearic acid, oleic acid, 9-, 10-, 11-, 12-, or 13- hyciroxy stearic acids, 10-, or l5-hydroxy palmitic acids, lO-hydroxy myristic acid, 5,6-dihydroxy stearic acid, 2,1l-dihydroxy palmitic acid, 12- hydroxy oleic (ricinoleic) acid, 12-hydroXy-9,l0- hexadecenoic(palmitoleic)acid, and l2-hydroxy- 9,10-tetradecenoic(myristoleic) acid.

The above types of fatty acids are to be reacted to form soaps with alkanolamines having less than six carbon atoms per alkanol radical and, preferably, with trialkanolamines. The most commonly available species and one which has been found to give satisfactory results is triethanolamine. Other species suitable for the present purpose are exemplified by the following list: mono-ethanolamine, di-ethanolamine, diamino-isopropanol, di-n-propanolamine, tri-isopropanolamine, butanolamines.

It will be apparent from the list of alkanolamines and higher fatty acids given above that the preferred type of soap comprises the soap of a trialkanolamine with an unsaturated hydroxy fatty acid having more than twelve carbon atoms in the molecule. However, derivatives of certain 3 4 natural products may be employed as Well. For presence of the additional fluid, such as that cl example, the triethylene amine soap of hydroscribed hereinafter as a water soluble Ucon genated castor oil acids is suitable in addition to fluid improves the gasoline resistance of the the following typical soaps: grease and, moreover, enables it to be used at Triethanolamine r1 cinoleate 5 low temperatures, such as occur at higher alti- Diethanolamine ricinoleate tudes, in the order of 65 without becoming T1,i isopmpaho1amme ricinoleate unduly sti ii. The water soluble fluids are pref- Monmbutanolamine ricinoleate erably those composed to a large extent of oxy- Triethanolamine lg hydroxysteamt alkylene units wherein the unit contains from Triethanolamine;Wmwlroxy myristate two to ten carbon atoms. The best fluid for the Triethanolamine g,lo;dihydmxy palmitate present purpose comprises the mono--ethers of Triethanolami-ne 12 hyd1.0Xy palmitoleate oxyalkylene polymers such as the lower monov alkylene others of 'polyalkylene oxides and gly- The Partial @8736" cols. In addition to the ethers of polyalkylene The fluid components of the present gasoline 15 Oxides or glycols, esters may be employed and resistant greases comprise two essential types. the polymers may be either homwpolymers The first of these is a partial ester "er a pei @"W more monomeric QXides hydr y alcohol, said alcohol having f two glycol's. Among these will be found trimethylene to ten carbon atoms with higher fatty acid-s. glycol ethylene glycol copglymsrs of ethylene Optimum results are obtained by the use of polyglycol and propylene glycol, co'pfilymers of liydric alcohols having from two to five carbon ethylsne Oxide and l'propylene Oxide and the atoms and, preferably, are glycol or glyceryl parlikeftia esters er unsaturated fatty acids, the latter It has b found that useful and improved having at least twelve carbon atoms per m-olepolwxyalkylene d t of relatively high aver m IM espscigmyy n gasoline resist age molecular weight, which are essentially mixy t pe ti are b d the use of e tures of true monohydroxy alcohols, may be obtialglyceryi esters of unsaturated hydroxy fatty mined by the addition to a mOnOh-YdYOX-V acidgi T v list which f u presents typical phatic alcohol or a mixture of alkylene oxides partial esters suitable for use in the present eontainmg ethylene Oxide and lpl'opylene oxide greas in a ratio preferably from about 50:50 to 75:25 Glycervl moxlorijcanoleafe ethylene oxide to 1,2-propylene oxide. By this Glycoljmon g Q or r de ratio is meant that in the oxide n'nxture, ehtaer thritormororioin 1 t which may be used in forming such monohy T y 0 ea 9 droxy alcohol addition products, the amount of G y c y' Q m 55 l,2--propylene oxide in the mixture is from V; to Carbitol ricinoleate (monoricmoleate of diethylan equal amount 0f ethylene Oxide present by ene glycol monoethyl ether) weight.

ai l r gzzte The reaction which takes place between the glyceryhmqno(lz hydroxysteamte) alcohol and the ethylene ox1de and propylene 40 oxide seems to "be a simple addition wherein the alkylene oxide molecules undergo conversion to the corresponding oxyalkyl'ene radicals as illus- Glyceryl-mono 9, lo-dihydroxypalmitate) Glyceryl-mono (1 2-hydroxypalmitoleate it will be noted that the above types ofpartial Hated fcr y given molecule by t e followin esters com-prise not only the simple partial esters general equatloni vof'pblyhydric alcohols with higher fatty acids but Ro-H +a/( o Eco +'z (O-Ha.-C2H oymroonmomu also comprise the partial esters of high fatty 0 Alcohol 5 a oxid p vlene 1,2-propylen'e Addition acids with 'mo'no-ethers of pol'yhydric alcohols. e Oxide p o tsetse are e r'elnplifi'ed by the C'arbitol ricinotea e. The Carbi-to'l is understood to be 'die'thylene "glycol monoethyl ether. Other ethers suitable -for this purpose include diethylene glycol me'netatyi ther, diethylene glycol monoethylen ethe'rand the mono-others of alkylene glycols such as ethylene glycol monobutyl ether.

wherein ROH is ail-aliphatic monohydroxy alcohoi; y and 2 represent the 'mol's of ethylene oxids and 1-,2-propyle'n'e oxide, respectively; rt is both 2 and '3 inasi'ng'le molecule, the total number of times 11 has a value of 2 being'equal to y and the total number of times-n has a value of 3 being equal to e; and a: is the total number The pozyowazkylene fluids or 'such oxyalk-yle'n'e groups, being equal to gH-z. I These polymers are preferably mono-etriers of he t d ess fl ponentoi the present polyoxyallrylene glycols with nionoliydric ali-= gasoline resistant grease compositions comprises phatic alcohols having from one to six-carbon water soluble 'pol'yo'xyalkylene fluids. It is deatoms and preferably from two to five. The sirabl'e, or course, to have this fluid not only be molecular "tv'eight isip'referably between biiland soluble in water but also miscible with the par- 1500. A typical example of this series comprises tial esters discussed hereinbefore. Preferably the -mixture of 'nionohydroxy oxyalltylene, oxythey'should have a volatility comparable to a me- 11,2-propylene butylmono-ethers-having an averiiiu'm'visc'osity lubricating oil but the latter propage molecular weight "of between 500 and i580 erty is no't'as important as its solubility in water 5 in which the ethylene oxide and LIE-propylene and its lack of solubility in gasoline or other light oxide are combined therein as "oxyethylene and hydrocarbons. The principal function of these oxy-LZ-propylene groups in-aratio oi part of fluids comprises the improvement of resistance to '1,'2-propylene oxide for each part by weight of washingaway, by gasoline or the like, of theparethylene oxide, the mono-ethers oi'isaid mixture tial esters and at the same time the improvement containing in i a single molecule both the oxyin the low temperature operating characteristics "alkylene and oxy-LZ-propylene groups. of the grease. It has been found that greases The 'fluids'which have been foun'dto be percomprising the ester and soaps, such as triethticularly suitable should have viscosities of beanolam'ine ricinoleate, operate fairly satisfactorily tween about 50- and 2,000 SUS-at 100 F. They only at ro'o'r'n temperature or slightly below. The v usually have viscosityindexes' v/hich'vary about 90 to 150. The pour points of the lower viscosity members, which are preferred, are between about -90 and --40 F. Their flash points, open cup, are between about 250 and 450 F. They have fire points, open cup, between about 275 and 550 F. The preferred varieties are those which have a viscosity between about 50 and 250 SUS at 100 F.

The greases The greases of the present invention comprise the three essential ingredients in the following proportions:

Amine soap: 5-25% by weight Water soluble polyoxyalkylene fluid: -50% by weight Partial ester: 30-60% by weight When proportions of this variety are employed a wide variety of greases may be obtained for particular purposes. Using amounts of soaps between 12 and 20%, one may obtain a grease having a medium consistency and which maintains a lubricating quality even at extremely low temperatures such as lower than 40 F. It is preferred that the weight ratio of polyoxyalkylene fluid to the partial ester be between 2:5 and 4:5. The best results are obtained when the polyoxyalkylene fluid comprises -40% of the grease and the partial ester comprises between 55 and 35% .by weight of the grease. The examples which. follow illustrate typical compositions of the present invention:

Example 1- Percent by weight Triethanolamine ricinoleate 20:-

50 HB 100 Ucon fluid Glyceryl monoricinoleate 50:

Example II- Triethanolamine ricinoleate I5 50HB 100 Ucon fluid 33;

Glycol monoricinoleate 52.

Example III- Triethanolamine ricinoleate lo 50 HB 100 Ucon fluid 30 Pentaerythritol monoricinoleate 60 Example IV-- Triethanolamine ricinoleate 25 50 HB 100 Ucon fluid 20- Diethylene glycol monoricinoleate 55 Example V- Triethanolamine ricinoleate 20 50 HB 100 Ucon fluid 50 Carbitol monoricinoleate 30 Example VI- Triethanolamine ricinoleate 20 50 HB 100 Ucon fluid 35 Glyceryl diricinoleate Example VII- Diethanolamine ricinoleate 18 HB 100 Ucon fluid 37 Glyceryl monoricinoleate 45 Example VIII- Ethanolamine ricinoleate 22 50 HB 100 Ucon fluid :28

Glyceryl monoricinoleate 50 Example IX- Di-n-propanolamine ricinoleate 16 50 HB 100 Ucon fluid 30 fit) Glyceryl monoricinoleate 54 7 Example X- Percent by weight Triethanolamine-12-hydroxystearate 12 50 HB Ucon fluid 34 Glyceryl monoricinoleate 54 Example XI 'I'riethanolamine-Q,lo-dihydroxystearate 20 50 HB 100 Ucon fluid 30 Glyceryl monoricinoleate 50 Example XII-- I Triisopropanolamine ricinoleate 20 50 HB 100 Ucon fluid 30 Glyceryl monoricinoleate 50 Example XIII- Triethanolamine ricinoleate 25 50'HB 55 Ucon fluid 20 Glyceryl monoricinoleate 55 Example XIV- Triethanolamine ricinoleate 5 50 HB 660 Ucon fluid 45 Glyceryl monoricinoleate 50 Example XV- Triethanolamine ricinoleate 20 Poly(propylene glycol) mol. wt. 250 30 Glyceryl monoricinoleate 50 Example XVI- Triethanolamine ricinoleate 20 Poly(trimethylene glycol) mol. wt. 300 30 Glyceryl monoricinoleate 50 Example XVII- Triethanolamine ricinoleate 20 -ester of butyric acid and poly(ethylene glycol-propylene glycol) mol. wt.

325 30 Glyceryl monoricinoleate 50 Example XVIII- Triethanolamine ricinoleate 20 A; butyl ether of poly(ethylene glycolpropylene glycol) mol. wt. 600 30 Glyoeryl monoricinoleate 50 Example XIX Triethanolamine ricinoleate 20 50 HB 100 Ucon fluid 30 Glyceryl mono-12-hydroxystearate 50 Example 2Q;-

Triethanolamine ricinoleate 20 50 HB 100 Ucon fluid 30 Glyceryl mono-(9,10-dihydroxystearate) 5 Example XXI-- Triethanolamine ricinoleate 19 50 HB 100 Ucon fluid 33 Glyceryl monoricinoleate 47.5 Phenyl alpha-naphthylamine 0.5

.Example XXII- Triethanolamine ricinoleate 18.0 50 HB 100 Ucon fluid 32.0 Glyoeryl monoricinoleate 47.0 Phenyl alpha-naphthylamine 0.5 -Oleic acid salt of 2-heptadecyl-hydroxymethyl-l-ethyloxazoline 2.5

"The oxidation and corrosion characteristics o'f these compositions are improved to an outstanding extent by the inclusion of a combinaftion .of :an aromatic amine and a higher fatty acid:salt of a substituted oxazoline having the generalnonfiguration:

R1\ /N=C-Rz R, on-o attests wherein'zRl anda-Rz are hydrogen, alkylnh dmxyr alkyl, .arylor :acyloxyalkyhradicals.andfiRs and R4 are .either hydrogen .or :alkyl rsuhsti ll Typical .members of tthis group ,will l-bfi (found in U. S. Patent 2,402,791. Additives which gney b employed n 1.de- .ee 9i l1 Jimrin least six carbon atoms andflprefer or more carbon atoms. ,Ifheygnay be saturated or unsaturated acids and," furthermore, may contain hydroxy groups resulting inqa hydroxy fatty acid. Typical speeiescmeeting these requirementsinclude caprioacid lauric acid, myristic 7 acid, oleic acid, tstearic acid, =l2ehydroxy oleic acid, 12-hydroxy stearic acl d and,.rnixtures of acids from n tura ggl st-ide 3191; aslfish oil fatty acids, coconut ,oi1,atty acids, an from animal fats andpils. ,Iypical o which may be utilized in salt formation with the above acids include the following:-the oxazolines utilized 'inpreparing the products Lon the-present invention may beanyof'a number of such compounds, as i for examp1e,-2 ethyl -.4 1hydroxymethyl 4 methyloxazoline, 2 i s op ropyl.. {ihydroxymethyl 4 r ne;thylqxaxoline ZJ-heptyl- 4 hydroxyrnethyl 4 je hy az ohne, 2' tridecyl 4 hydroxymethyl methy'lo v aaqline, 2 octyl 4 hyd'roxym'ethyl 4 ethyloxazoline, 2 hendecyl 4 hydroxymethyl 4 methyloxazoline, 2 --hendecyl 4 -hydroxyme-thyl 4 ethyloxa-zoline, Z-heptyI-i-Khydroxyrnethyl) oxazoline,- Z-heptyl 4,4 --bis (hydroxyrnethyl) Q oxazoline, 2-octyloxazo1ine, 2-hendec-yl-4 4 bisthy- 2-hendecyl-4,.4-din1 h it b e "s l h l .aqi a rhflllil. i t y a o ne th clzihzdres of 2- ethyl -4- hydr oxymethyl -4- r n yloxaaolinc and the stearlc acid salt of; a des 521;44- dimethyloxazoline.

The aromatic amines to be combined with these oxazoline salts include; particularly, polycycloamines of whichthe'pr'eferred species is phenylalpha-naphthylamine. It is preterged that the group contaimat; leastnonecphenyl gradical andthat inaddition-theretd another h carbon gronpgor;i substituted hydrocarbon gr be directly attached to the nitrogen atom. Tlj ese amim siaiberem e QQQ rEEQP having the structural con figu wherein R is a hydrocarbon or a substituted bydrocarbon radical. Typical species dinclude phenyl beta naphthylamine, ..-dipheny1amine, phenylstearylamine and: the :like.

. We claim as our invention:

1. A gasoline-resistant grease-comprising a gelling amount of. ihydrioxyalkylaminessoapIiof a higher .fatty acid, :20-50% .by,. weight of; a water acids gthylen and.oXy-..l,2-propylenegroups ina ratio fmm about one-third .to' .one part .1,2-propy1en. oxide. for ,each part .of .ethylene oxide "by weight, the monoethers of saidrnixture containing in a single .molecule both the .oxyethylene and goxy- 1,2 propylene groups and. 30-60,% iby.,w.eight ,of glyceryl ,monoricinoleate.

3. A gasoline-resistant grease comprising a gelling amount of "a "hydro'xyalkylamine soap of an .unsaturatedfiatty .acid, .30-50 t by Weight of almixtu'rfe crmonchydrqxy vcxyethylen foxy-1,2- propylene butyfmonoeth'er's' an'. verage molecular weight of at least 900 in which'ethylene oxide and Lz-pr'opylene QXideare combined therein as oxyethylene land .oxy-LZ-propyl'ene groups in a ratio from one part to nine partsof 1,2-propylene oxide l-for ,each part of ethylene oxide, by weightthe monoethers of said mixture containingin a single molecule both theoxyethylene and the oxy-Lz-propylen group, and 30-60 weight of apartial este'rof 'g1yceririe anda fatty acid having at least twelve carbon atoms.

4; A gasoline-resistant grease comprising a gelling proportion of a hydroxyalkylamine soap ofan iinsaturated' hydroxy fatty acid, 30-50% by weight of a mixture of 'monohydroxy oxyethylene oXy LZ-p-ro lene butyl' monoethers having an average mo ecular :weight of atileast 900 in whichiethyleneo ide and Jig-propylene oxide arecombined thereina's oxyethylen'ean'd oxy-1,2-propylenegroupsfin a ratio frjorn' oiie part to nine parts of 1,2-propylen'e' oxide for each part of ethylene oxide, by weight, the nonoethers ofsa id mixturenontaining in a singlernolecul e both the ox'yethylene andthe. voxy- 1,2 -p r0pylene group, and 30-60% by weightbta partial ester of glycrine' and an. "unsaturated fatty acid. having at'l'ea's't twelvecarbbn atoms.

fat ci 7 A;ses l e is antgrace r m a propylene oxide are combined therein as oxy- 5. A gasoline-resistant grease comprising a gelling amount..of..a.hydroxyalkylamine soap of an unsaturated,,hydroxylfatty acid having at least twelve. carbon atoms", -50% by weight of a mixture of monohydroxy oxyethylene orgy-1,2- pr opylene butyl monoethers having ffa'n average molecular weight of "at least 900 in, w hi ch ethylene oxide and 1,2-propylehe oxide are'comb-ined therein as oxyethylene and"oxy-'1,2-prop'ylene groupg in a ratio from one part to nine parts 2. 1 1 93 93 5 l h ar 9 th l oxide, by weight, the n onoethers of,said mixture eq ta a ne i I a s n l m ecu ot h pa ethylene and the oxy-1,2propylene group, and -60% by weight of a partial ester of 'glycerine and anunsaturatedfatty' acid having "at least twelve carbon atoms.

'6. A gasoline-resistant grease comprising a gelling amount of triethanolamine soap, of an unsaturated hydroxy fatty acid having ,at'least twelve carbon atoms, '3'0-50 b'y. weigl'it of a mixture of monohydrox'yoxyethylene' oxy l,2:propylene butyl nionoethefs" having "an "average moneular weight of a least 900 in which ethylene oxide and .1,2.-.pro.pylene oxide are combined therein .as ,.oxyethylene and oxy-l,2-propylene groupsin..a.ratio.from.onelpart to nine parts of 1,2-propylene oxide for each part of ethylene oxide, by weight, the monoethers of said. mixture containing in a singlemolculeiboth thejoxyethylene and the oxy-l', 2 -propy lene group, and

;; sql il ah 'wl iiip j aaaitamami seaap an 9 unsaturated hydroxy fatty acid having at least twelve carbon atoms, 30-50% by weight of a water soluble polyoxyalkylene fluid and 30-60% by weight of glyceryl monoricinoleate.

8. A gasoline-resistant grease comprising a gelling amount of triethanolamine ricinoleate, 30-50% by weight of a water soluble polyoxyalkylene fluid and 30-60% by weight of a partial ester of an unsaturated higher hydroxy fatty acid and 01' a polyhydric alcohol having less than four carbon atoms.

9. A gasoline-resistant grease comprising a gelling amount of an alkanolamine soap of an unsaturated hydroxy fatty acid having at least twelve carbon atoms, 30-50% by weight of a water soluble polyoxyalkylene fluid, and 30-60% by weight or a glyceryl monoester of a, fatty acid having at least twelve carbon atoms per molecule.

10. A gasoline-resistant grease comprising a gelling amount of trialkanolamine ricinoleate, 30-60% by weight of glyceryl monoricinoleate and 20-50% by weight of a mixture of monohydroxy oxyethylene oxy-1,2-propylene butyl monoethers having an average molecular weight of at least 900 in which ethylene oxide and 1,2- propylene oxide are combined therein as oxyethylene and oxy-1,2-propylene groups in a ratio from one part to nine parts of 1,2-propylene oxide for each part of ethylene oxide, by weight, the monoethers of said mixture containing in a single molecule both the oxyethylene and the oxy-1,2-propylene group, said composition also containing minor amounts sufficient to improve the oxidation and corrosion characteristics thereof of phenyl-alpha-naphthylamine and of 4 wherein R1 and R2 are substituents of the group consisting of hydrogen, and alkyl, hydroxyalkyl, aryl and acyl-oxyalkyl radicals and R3 and R4 are radicals of the group consisting of hydrogen,

and alkyl substituents.

HAROLD A. WOODS. LOREN C". BOLLINGER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,083,132 Williams et al June 8, 1937 2,425,845 Toussaint et a1 Aug. 19, 1947

Claims (1)

1. A GASOLINE-RESISTANT GREASE COMPRISING A GELLING AMOUNT OF HYDROXYALKYLAMINE SOAP OF A HIGHER FATTY ACID, 20-50% BY WEIGHT OF A WATER SOLUBLE POLYOXYLALKYLENE FLUID AND 30-60% BY WEIGHT OF A PARTIAL ESTER OF A POLYHYDRIC ALCOHOL HAVING LESS THAN SIX CARBON ATOMS WITH A HIGHER FATTY ACID.