US2790779A - Rust preventive compositions containing monoamidocarboxylic acids - Google Patents

Description

2,190,179 Patented Apr. 30, 1957 RUST PREVENTIVE COMPOSITIONS CONTAINING MONOAMIDOCARBOXYLIC ACIDS John D. Spivack, Craustou, Robert M. Pines, Providence, and Harry Kroll, Warwick, R. 1., assignors to Gcigy Chemical Corporation, a corporation of Delaware No Drawing. Application July 27, 1953, Serial No. 370,619

16 Claims. (Cl. 252-392) This invention relates to rust preventive oleaginous compositions. More particularly the invention relates to the use of certain nitrogenous corrosion or rust inhibitors in compositions containing predominantly an oleaginous vehicle, and which compositions may become contaminated with water or steam.

The prevention of rust formation is particularly important in the protection of metal surfaces, particularly ferrous surfaces, where such surfaces are to be lubricated in the presence of contaminating moisture. Moisture may enter lubricating systems of land and marine turbine engines, for example, by leakage through steam glands and through water-cooled heat exchangers or simply by condensation from the atmosphere. The presence of rust is injurious because it causes excessive wear of gears and bearing surfaces, and may also clog the hydraulic governor system, which last result may lead to dangerous operating speeds. Furthermore, the presence of rust has been shown to increase the rate of oxidative breakdown of the lubricant. The prevention of rusting is also essential in the moving parts of hydraulic systems generally, such as hydraulic bailing machinery, presses, etc. important applications of rust preventive compounds are in preservative oils, slushing oils, flushing oils, etc.

A great many materials have been proposed for the prevention of rust formation of metal surfaces, however, relatively few have been applicable in practice for the protection of lubricant systems because most are deleterious to the lubricant, the lubricant system or are disadvantageous in some other way. It has been proposed to add various carboxylic acid amides to hydrocarbon oils either for rust prevention or in order to improve the film strength and adhesion to metals. U. S. Patent No. 2,462,358 incorporates an acetoacetyl amide with an acyl residue which is of a higher fatty acid or naphthenicacid, such as C17H37CONHC2H4NHCOCHzCOCHa, for the latter purpose. And U. S. Patent No. 2,403,293 discloses the incorporation of oleic monoamide of ethylene diamine or of polyethylene polyamines, purportedly a rustproofing composition. There has also been issued U. S. Patent No. 2,270,113 on esters of glycine or alanine added to oils to inhibit corrosion.

According to the present invention, it has now been found that the corrosive effect of lubricating oils and greases (oleaginous vehicle) upon bearing surfaces, gears and other metallic parts in the presence of water may be prevented by the incorporation in said oleaginous vehicle of a small amount of a class of compounds which are monoamidocarboxylic acids and their salts in which a high molecular weight aliphatic acid residue is bound to the amide nitrogen, and more specifically characterized below. Such compounds, it has been determined on a scientific basis, effectively prevent the rusting of metal surfaces, particularly those of ferrous metals, upon exposure to water or steam, when used in small amounts in lubricating compositions. These additives moreover prevent rusting without influencing the lubricant action disadvantageously.

Other 2 The rust preventive compositions of this invention consist of major amounts of an oleaginous vehicle and a minor amount of the class of compounds monoamidecarboxylic acids having the empirical formula where R1 represents an aliphatic carboxylic acid residue of CaC-24, or alkyl phosphoryl, alkyl phosphonyl, alkyl sulfonyl wherein the alkyl radical has this same number of carbon atoms; where R2 represents an alkyl, hydroxyalkyl, phenyl group or H; R3 represents an alkyl, carboxyalkyl groups or H; n represents 0 or 1; X represents H or groups capable of forming salts with the carboxylic acid groups such as ammonium or substituted ammonium groups, e. g. organic amines, metals, etc.

The higher molecular weight acid in the amide group can be any of the higher fatty acids, either saturated or olefinic unsaturated, of this chain length, such as-from caprylic acid through behenic in the saturated series. Many of these higher saturated and unsaturated fatty acids occur as glycerides in fats and oils in nature or as esters of monohydric alcohols in waxes. But higher molecular weight aliphatic acids Within this general class which do not occur naturally, such as the mixed carboxylic acids in oxidized liquid or solid hydrocarbons, can be used. It will be understood that mixed acids can be used of any of these sources, i. e., mixed higher fatty acids, or the synthetic mixed aliphatic acids from hydrocarbon oxidation, or mixtures of each, etc.

The members of this class of compounds, which are the additives of the present invention, may be regarded as derivatives of the natural and synthetic amino acids, for example derivatives of glycine, a or 13 alanine, sarcosine, aspartic acid, glutamic acid, leucine and other better known amino acids. These amidocarboxylic acids and their salts can be prepared in a number of ways, e. g. as outlined in Equations A or B.

o B. R. o a, Rdo1++oH oHi ..000K Q RilN-t'JEKOHzhCOOK o In alkali Rti'lN-(JHGJHQJJOOH (B) in The members of this class of compounds can be used alone in an oleaginous vehicle or -solvent. The latter may be termed the lubricating oil or -grease when the designation is thought of broadly. When used in an oleaginous vehicle, these compounds should be soluble, miscible or dispersable in the vehicle. If the amidocarboxylic acid or its salts is not soluble therein, at least in the percentage added solubilizers may be added which bring this about; a suitable agent for this purpose is disclosed subsequently. The term oleaginous vehicle as used in the specification and claims includes mineral lubricating oils derived from the refinement of petroleum or any of the so-called nonmineral oils, such as animal, vegetable oils, fats, the synthetic polyesters or organic acids, polysiloxane, polyalkylene glycols, polyolefins, also the rust-proof bases which may be used as the medium of application of rust preventive additive to the metal surface.

qmem m s fl helu t qa s. asevwi libel rsr. ferredfor specific applications while other members will be preferred for other technical, industrial applications, where rust prevention is the objective. For it is obvious that the type of .lubricating oil or grease for suchsur v faces as machine parts, piston rings machine guns, light arms; s i'wr' ne fths q nsra s draul c baling machinery; or presses, metal'drurns, etc., will vary greatly.

Some members of this class of compounds, namely the monoamidocarboxylic acid additives, will be preferred a d ersl i l F b 1 ie s m are achieved in practice by specifying that.

11 lubricant pass "certainru'stpreventive nd One of .Z'tli rust preventive tests idelyi'used is 'the':Static"Water, Drop .Coi"ro sion eyeloped by Zisman'etaliand,des i edinflndns trial and Engineering: Chemistry, 'fvoluine "El-[page fl. f '(19 4 9 Brji yfthisjtestinvolves'Qobserving rusting at140 F. in th p esericjeofta dropfof'fdistilled Waterin I thedir'nple of atr'ia'ngular' cold-rolled steelspecimen' immersetl in the test oil. adequately rust inhibitedoil will"pr eve nt frusti'n'g 'for severalfdays' while a straight mirieraljbt fwill' permit 'rusting' within several hours. H Th""den-iulsibility properties of lubricating oils are charf f; 'zedfbytheFedral' Standard Stock Catalog method dated .NQvember" l5,"19 i8, and entitled Emil sion (Lu'brf' atingQO Briefly, this test involvesmi ing'" 40 millzlitersof water and "41) "illilitersflofest. oil. at 130 F. or 180 F. understanda'rd eenaitiens anu; observing the separation of oil and water phases at the" test temperature. f Theftest temperature selected is usually 130 F. for light viscosity turbine oils up. to about 500 1 Saybolt Universal seconds at 100 F. The U. S. Navy specifies ;that 2190Tgrade turbine oils separate from water inthis test within 30 minutes and have not more than 3 m'illiliters'of'an intermediate oil and water phase at this time in order to comply with Navy 140l5 Specificatioiis This criterion of demulsibility is widely adopted by turbinj'e' oil producers End: consumers.

The amount of corrosion inhibitor incorporated in the finished lubricating composition may be vervsrnall amounts of the order of O.0125% 1 base d on the total finished'oil lubricant; b eing sulficient to secure metallic corrosion preventiongmoreparticularly where the. surface is terrous innature. Greater amounts may be added as f r' i e s fli smea s' and P =9ncm wn;a

of the more important usespf the. various types mono-"carboxylic acids of the present invention, in turbine lubrication; are thefollowing; Metal 7 d forming operations, gears and bearings under. v con tions of extreme ppressureprnotor oil for internal combustion engines, and tap" cylinder lubricants. v p

The. followingexamples are offered to illustrate, but not to lir njihthe manner in .whicl the present invention may bepra 'i'sed.

"' eM LE 7.5. gramsof glycine was dissolvedin 100- milliliters of water containing 4.0 grams of sodiumhy'dro'xide. "30.2 ams of .stearoyl chloride and 50-milliliters ofaqueous sodium hydroxidewo'ntaining 4.0 gramsof sodiunif 113ll 7.

terisls. era imultensuusly ddsdlqihe llialineslr iue.

solution over a period of 20 minutes while maintaining the temperature of the mixture at about 25 to 35 C. The reaction mixture became turbid and viscous and was stirred for an additional hour. It was then neutralized to pH 2 with dilute hydrochloric acid. The precipitate which, formed was. filtered, washed with-water, andair-- dried for two days. It weighed '3 1.6 grams- Recrystallization from ethyl acetate yielded a white product which melted at 123 C. and had a neutralization ecpgivalentwei-ght of The heore a 'nei t e izati n u val n weight of (N-stearoyl) glycine is 341.

The product described inthe example was tested for its rust preventive properties by dissolving it in a solventrefined and filtered. non-additive turbinegrade lubricating mineral oil of 150 Saybol-t Universal seconds viscosity at F. and subsequently testing this oil solution by the Static Water Drop Corrosion Test? described above.

EXAMPLE II 10.2 grams, 0186percent sareosineland 6.1 grams of magnesium oxide were dispersed in 200 milliliters of water and 30.2 grams stearoyl chloride was. added dropwise over, a period. of thirty-five minutes. The reaction mixture was stirred for an additional 1.5 hours at room temperature and then .made acid topH 2 With dilute hydroohloric acid. The precipitate which formed was filtered, washedwith water and air-dried. The yield .Was.

100 Fuand subsequently testing this oilsolutionby the Static Water Drop Corrosion Test and Emulsion Test described above.

' EXAMPLE III 11.8 grams of 75.5 percent sodium sarcosine wasdissolved .in. 100.. milliliters of water and 21.7 grams of lauryLchloride and 54. grams of aqueous sodium hydroxide containing 4.0 grams of sodium hydroxide were added dropwisesimultaneously over a period of 30 minutes.- On-..acidification ofthe mixture to pH 2 with 6 N hydro-- chloric .acid a buttery...white solid-separated which was extracted .with ether; ..the ethereal solution was thereupon On" removal of; ether,..the residue .Weighed2L3 grams andhad aneudried over: anhydroussodium sulfate.

tralization .equivalenrw'eight of 275K The theoretical neutralization equivalent weight for .(NJauroyl) sarcosine isr.27.l.. "Aftencr'iystallizationfromh-hexane (N- lauroyllsarcosinehad a melting pointv of 45th 47C;

Theeproduct described in theexample was tested-foritstrustlpreventive properties by dissolving it in a solvent refined and filtered non-additive turbine grade lubricating mineral oil of Saybolt Universal seconds viscosity at 100%. F.a=(37.8. C.) and. subsequently testingthis oil solution by the .fStatioWater Drop Corrosio-nTest described 1 above EXAMPLE IV 5.4 grams of m alanine was dissolved in 62.7 milliliters of 1l00 N'NaOH solution 18.5 grams of stearoyl chloride and 65 milliliters of; l.00 -N aqueous caustic soda were added dmpvviseQsimultaneously. over a period of 25 minutes. The reaction mixture was stirred for an additional 30 minutes and then acidified with 6 N hydrochlori'c acid to pH 2. 7 The precipitate which formed was filtered, washed with water and allowed to air-dry, yield ing 2l'l3 granis' ofa white solid. After recrystallization successively from acetone and carbon. tetrachloride, the

isolated (N-stearoyl) t1 alanine melted at lOS-IIO". C. and had a neutralization equivalent weight of 360. The

theoretical neutralization equivalent weight of (N-stearoyl) a alanine is 356.

The product described in the example was tested for its rust preventive properties by dissolving it in a solventrefined and filtered non-additive turbine grade lubricating mineral oil of 150 Saybolt Universal seconds viscosity at 100 F. and subsequently testing this oil solution by the Static Water Drop Corrosion Test and Emulsion Test described above.

EXAMPLE V 8.9 grams of S alanine was dissolved in 100 milliliters of water containing 4.0 grams of sodium hydroxide. 30.2 grams of stearoyl chloride and 25 milliliters of aqueous sodium hydroxide containing 4.0 grams of sodium hydroxide were added dropwise simultaneously over a period of thirty minutes. The reaction mixture was stirred for an additional hour at room temperature and then made acid to pH 2 with dilute hydrochloric acid. The precipitate which formed was filtered, washed and air-dried, but since it showed a considerable ash on ignition when tested, it was redissolved in 500 milliliters of aqueous alkali containing 200 milliliters of 1.0 N sodium hydroxide in which it was clear when hot. This solution was also cooled to room temperature, then made acid to pH 2 as had been done in a prior step. The precipitate which formed was filtered, washed with water and airdried. The dried precipitate weighed 36.0 grams and had a neutralization equivalent weight of 368. The theoretical neutralization equivalent weight of (N-stearoyl) 8 alanine is 356. On recrystallization from ethyl acetate the purified (N-stearoyl) [-3 alanine melted at 1l9-l20 C.

The product described in the example was tested for its rust preventive properties by dissolving it in a solventrefined and filtered non-additive turbine grade lubricating mineral oil of 150 Saybolt Universal seconds viscosity at 100 F. and subsequently testing these oil solutions by the Static Water Drop Corrosion Test described above.

Solubilization of some of these amidomonocarboxylic acids synthesized in the above examples was eifected when required by the addition of a solubilization agent which per se in oil solution had little if any rust preventive properties. The agent used was a commercially available primary, aliphatic amine, which has the tertiary-alkylamine structure, the tertiary alkyl groups having from 18-24 carbon atoms. Emulsion tests were also run on some of these oil blends. The test results are given in Table I.

It is evident that the rust preventive effectiveness of lubricating oil solutions of the monoamidocarboxylic acids is much improved over" the base oil alone or with the solubilizer in it. It is also evident that the monoamidocarboxylic acids are qualitatively superior in rust preventive effectiveness than a typical high molecular weight fatty acid, such as stearic acid or the latter admixed with this identical solubilizer.

While the utility of our invention is illustrated by reference to its adaptability to turbine grade mineral lubricating oils, it is to be understood that this is intended to be merely illustrative and not a limitation of the scope thereof. Thus our invention is applicable to other oils, whether or not comparable in specification and origin, including emulsifiable soluble oils, liquid fuels, greases, and in general compositions in connection with which the water-corrosion of the containing system is to be avoided.

Having disclosed the nature of our invention and the manner in which it may be practiced, what we claim and desire to protect by Letters Patent are the following:

1. A rust preventive oleaginous composition adapted for use in the presence of water, in systems containing metal susceptible of corrosion by water, comprising an Table I.'Rust preventive and demulsibility properties of aminocarboxylic acids in lubricating oil Static Water Ex- Wt. Wt. Emul- Drop Additive (A) ample Per- Percent sion Corrosion No. cent Primene Test Test (A) (A) J MR 1 Time to Rust (Hours) Base Oil N one None Pass Less than Stearic Acid None Pass Do. "Primene JMR 0. 20 Pass Dc. Stearic Acid and Pri- 0. 20 Less than mene JMR. 2. (N-stearoyl) glycine. I 0. 025 0. 025 M200? than (N-stearoyl) sarcosine. II 0. 0125 None Pass D0. (N -laur0yl) sarcosine III 0.0125 0.0125 D0. (N-stearoyl) a alanine- IV 0.0125 0.0125 Pass Do. Do IV 0.20 None Do. (N-stearoyl) B alanine V 0. 10 0. D0.

1 Primene JMR is a mixture of highly branched, aliphatic primary amines having the tertiary-alkylamine structure in which the primary amino nitrogen is directly attached to a tertiary carbon atom; it is composed principally of amines from eighteen to twenty-four carbon atoms and the predominant portion may be represented by the formula, tCis-24Hs1-4oNHz. It contains about 23-10% non-amine material. It; is a non-viscous liquid, colorless to straw colored, insoluble in Water and does not; dissolve water to an appreciably extent. It exhibits solubility in hydrocarbon solvents and glyceride oils or fats, and in other organic liquids previously referred to under the term oleaginous vehicles. Additional physical properties are:

Formula Principally t-OmHuNH: to

t-Cu t9 2. Molecular Weight Principally 269-353. Specific Gravity, 25 O.. 0.828.

Color, Varnish Scale 4-. This product designated by the trademark Primene J MR" is a product of Rohu & Hass Company.

oleaginous vehicle and a monoarnidocarboxylic acid having the following empirical formula:

where R1 represents an aliphatic carboxylic acid residue of C8C24, R2 represents a substituent selected from the group consisting of H, alkyl, hydroxylalkyl and phenyl group, R3 represents a substituent selected from the group consisting of H, alkyl and carboxyalkyl, and n represents O or 1, and X represents H and groups capable of forming salts with the carboxylic acid group, said monoamidocarboxylic acid being present in said oleaginous composition in minor amounts, as little as a fraction of 1% to amounts greater than 1% but in suflicient quantity to inhibit the corrosion of said metal to :a great degree when compared with the check.

2. A rust preventive oil composition adapted for use in the presence of water, in systems containing metal susceptible of corrosion by water, comprising a hydrocarbon oil and a monoamidocarboxylic acid having the following empirical formula:

to amounts greater than 1% but in suflicient quantity to' where? R1 represents an aliphatie carboxylic acid residue OfCG-Czt, R2 represents asubstituentselected from/the. group. consisting of- H, alkyl, hydroxylalkyl-.andphenyl. group, R3 represents a substituent selected from the group consisting of H, alkyl, and carboxyalkyl, and n represents-0 or 1, and;X represents H and groups capable of forming salts with the carboxylic acid group, said monoamidocarboxylic acid. being, present in said oleaginous composition in, minor amounts, as little as a fraction of 1%toramoun-ts greater than 1% but'insutficient quantity to-inhibit thecorrosion of, said metal to a great degree when compared with the check, and :an alkyl primary amine having 18-24 carbon atoms in sufiicient amount to solub'ilize said monoarnidocarboxylic acid.

4-. Arust preventive oil composition adapted. for use in the presence of Water, in systems'vcontaining metal susceptibleof corrosion by water, comprising a hydrocarbon oiltanda monoamidocarboxylic acid having the following empirical formula:

s R1N-(']H(CH2)COOX in where. R1 represents an aliphatic carboxylic acid residue of (la-C24, R2 represents a substituent selected from the group consisting of H, alkyl, hydroxylalkyl and phenyl group, R3 represents a substituentselected from the group consisting of H, alkyl and carboxyalkyl, and n represents 0 or 1, and Xrepresents H and groups capable of forming salts with the carboxylic acid group, said monoamidocarboxylic acid being present in said oil compositionin minoramounts, as little as a fraction of 1% to amounts greater than 1% but in sufficient quantity to inhibit thecorrosionofi said metal to a great degree when comparedwith the check, and an alkyl primary amine.

the -,presenc,e.-ofv Water, insystem containing metal susa ceptible of corrosion by said Water, comprising an oleaginous vehicle and minor amounts of (N-stearoyl) sarcosine of as little as a fraction of 1% to amounts greater than 1% but in suificientquantity to inhibit the corrosion of said metal to a great degree when compared with the check.

7. Axust-preventive composition adapted for use in the:presence oi= water, in systems containing metal susceptible of corrosion by saidwater, comprising an oleaginous vehicle-and minoramounts of (N-lauroyl) sarcosine. of asdittle'as atraction of 1% to amounts greater than .-1%--but in sufficient quantity to inhibit'the corrosiomof said metal-to a great degree when compared with the check;

8i A1 rust preventive composition adapted .for use? in the pre-sence of water, in systems containing metal susceptible of"co1:rosion bysaid water, comprising anoleaginous vehicle and minor amounts of (N-stearoy'l)" alanine ofas little as a fraction ofi l to amounts greater than '1 but in Suificientquantity to inhibit the corrosion of 'said metal to a g-reat'degree' when compared with the check;

9. A rust-preventivecompositionadapted for use in the presence of water, 'in systems-containingflmetal susceptible of corrosion by said water, comprising "a'mineral oil and minor amounts of (N-stearoyl) glycine of as little as a fraction of 1% to amounts "greater than 1% but in sufiicient quantity to inhibit the corrosion of said metal to agreat degree. when compared with the check.

10. A- rust=preventive composition. adapted'for use inthe presence of water, in systems. containing metal .sus-

ceptiblev of corrosion by saidwater, comprising amineral oil andminor amounts of (N-stearoyl) sarcosine ofas little as attraction of V1% to amounts greater. than. 1%. but

12. A rust-preventive composition adapted for use in theispresence of water, in systems containing metal susceptible of fcorrosion'bysaid watenscomprising a mineral oil and. minor'amounts of (N=stear.oyl) alanine of as little as a-fraction of 1%:-to. amounts greater than l%=but in-sufii'cient quantity to inhibit thecorrosion. ofsaid metal to a great :degree when compared. with the .check.

13. A rust-preventive composition adapted to use in thepresence"of water, in systems containing metal susceptible of'corrosionby said water, comprising a mineral oil and minor amounts of (N-stearoyl) glycine, as little as a fraction of 1% -but in a sufiicient quantity-to inhibit the corrosion of said metal to a great degree when compared with the check, andalkyl-primary amines having 18-24 carbon atoms in sufiicient amount to solubilize' said (N-stearoyl) glycine, in themineral oil, the said alkyl amines being soluble in the mineral oil but insoluble in water.

14. .A rust-preventive composition adapted to. use in the .presencesofiwater, in systems containing .metal susceptible of corrosion by said Water, comprising a mineral oil andminoramounts of (N-stearoyl) sarcosine, as little as a fraction of. 1% but ina sufiicientquantity to inhibit thecorrosion-of said. metal to agreat degree when compared with the check, and alkyl primary amines having 18-24 carbon atoms in sufiicient amount to solubilize said (N-stearoyl) .sarcosine, in the mineral oil, the said alkyl amines being soluble in the mineral oil but insoluble in'water.

15. A rust-preventive composition adapted to use in the presence of-water, in systems containing metal susceptible of corrosion by said water, comprising a mineral oil and'rninor-amounts of '(N lauroyl) sarcosine, as little as a fraction 051% but in-a sufficient quantity to inhibit thecorrosionofsaid metal toa great degree when compared with the-check, and alkyl primary amines having 18-24 carbon atoms in sufficient amount to solubilize' said (N-lauroyl) sarcosine, in the mineral oil, the said:

alkyl amines being soluble in the mineral oil but insoluble in water.

16. A rust-preventive composition adapted to use in ficient'iquantity to'inhibit the corrosion of said metalito' a great degree when compared with the cheek, and alkyl primary amines having 1824 carbon atoms in sufficient amount to solubilize said (N-stearoyl) alanine, in the mineral oil, the said alkyl amines being soluble in the mineral oil but insoluble in water.

References Cited in the file of this patent UNITED STATES PATENTS White et a1 May 12, 1953

Claims (1)

1. A RUST PREVENTIVE OLEAGINOUS COMPOSITION ADAPTED FOR USE IN THE PRESENCE OF WATER, IN SYSTEMS CONTAINING METAL SUSCEPTIBLE OF CORROSION BY WATER, COMPRISING OLEAGINOUS VEHICLE AND A MONOAMIDOCARBOXYLIC ACID HAVING THE FOLLOWING FORMULA: