US2790780A - Rust preventive compositions containing diamidocarboxylic acids - Google Patents

Description

United States PatentO RUST PREVENTIVE COMPOSITIONS CONTAINING DIAMIDOCARBOXYLIC ACIDS John D. Spivack, Cranston, and Harry Kroll, Warwick,

R. 'L, assignors to Geigy Chemical Corporation, a corpdration of Delaware N Drawing, Applicatigm'JIllyI2 7, 1953,

Serial N0.370,617

12 Claims. ,(Cl. 252-692) invention relates to-ruist preventive oleagi nous compositions;- More articularly theinvcnncii relates to the use of certain nitrogenous corrosion or rust inhibitors in compositions containing predorifinaritlyafi oleaginousvehicle, and which compositions may become contaminated withwater or steam,

The'pfevention of rust formation 'is' particularly important inthe protection of metal surfaces, particularly ferrous surfaces'wheresucli surfao'esare' to he lubricate'd in the presence of contaminating moisture. M ois'ture'may enter lubricating systems 'ofland-land marine turbine-engines; for example, by leakage through steam glands and through water-cooled heat exchangers or sn'nplyuby condensation from the atmosphere; The presence of-rust is iniuriousb'ecause"it"causes excessive wear of g'eiar's and bearing surfaces; and may also clog the hydraulicover: nor system, which las't result"may lead to 'dangerousmper ating" speeds. Furthermore, the presence of rust hasbeen shown to mcrease the rate of oxidative' breakdown of the lubricant The prevention of rusting is alsdcssential in the movingpart-s of hydraulic'syst'ems generally, such ashydraulic baling'f' machinery, presses; etc. Gther intportant appli-a'tio'hs "of rust" preventive compounds are in preservative-oils,'sluslring'oils; flushing oils, etc

A great many materials" have been proposed for pr cvention of rust formation of metal surfaces, however,

relatively few have been applicable iri'pnacticedforthe protection of lubricant systems because most are deleterious to the lubricant, the lubricant systemor are disad= va'ntageous in some other way. lthas been proposed to add various carboxylic .acid amides to hydrocarbon oils either tor rust prevention or in order to improve the film-i st nength andwadhesion towmetals. U. S.P.atent No. meassswmmrpcmm an aoe'toacetyl am-ideh'aving an acylre'sidue whi'chis lot a higher fatty acid or naphthenis: acid, such .as C17H37CONHC2H4NHCOCH2COCH3, formelauerpurpsse; And IL-S. Patent N-fol 2,403 ;293'dis= closes the incorporation of oleic monoamide of ethylene diarfiine or of polyethylene polyamines, purportedly a rustpmofirig composition; I It is claimed in'U. 8'. Patents NO;' ,490;74 1- Of December 6, 1949, and'N0.-2,540;800 of February 6, 1951, (that the lalkenyl succinic anhydride .mrine reaction product" oonfcrsrust' proofing properties lil'bi'lca't-lllfg'follsl Accordingwto' the; presentinvention, it has now been found that" the corrosive efiect of lubricating oils and greases-(-o1eaginousvehicle) upon bearing surfaces, gears and other metallic parts "in the presence of water imay be prevented ay incorporation in asaid-oleaginous ve hicle-of a' -smau amsumcra class of compounds which are 'di-amidocarboicylic acids and their salts, in whichai high molecular weight aliphatic acid residue is boundto an amide nitrogen; substituted also by a carbamyl'alkyl group and by a carboxya-lkyl group. Such compounds;- when' used in small amounts in lubricating compositions, it has been determined'ona scientific basisg-ieifeeti-vely prevent the rusting of metal-suriaces; articularly" those of ferrous metals, upon exposure to water or steam.

2,7 90,180 Patented Apr. so, 1957 2 These additives moreover prevent rusting without influencing the lubricant action d sadvantageously.

The rust prevention composition of this invention consists of ni'ajor amounts of an ole'aginous vehicle and a minor" amount of the class of compounds diamidocarboxylic acids and their salts having the empirical formula (CHzMCONRzRi (onumooox whereRi-represents an aliphatic carboxylic acid residue of CsC24,-or alkyl phosphoryl, alkyl phosphonyl, alkyl sulfonyl, alkyl sulfuryl, wherein the 'alkyl radical has this same number of carbon atoms; where n. and m' represent the integersl or 2; where R2 and R3 respectively represent alkyl of aryl groups or H; and X represents H or groups capable of forming salts with the carboxylic acid group, such as ammonium or substituted ammonium group's, e. g.- organic amines, and metals, etc.

The higher molecular weight acid in the amide group can be anyof the higher fatty acids, either saturated or olefinic" unsaturated, of this chain length, such as from ca'pry'lic acid through behenic in the saturated series. Many of these higher saturated and unsaturated fatty acids occur as glycerides in tats and oils in nature'or as estefs ofm onohydricalcohols 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 diamidocarboxylic acids-and their salts of the present invention can be prepared in a number of ways, e. g. as outlined in Equations A, B, or C below.

0 show NH (OHi)mCN NaOH 0 our con-m" l aqueous }CHt)mCOONa lnx 0 (crmnoonm .0 (ononooNm he Hi) mo 0 0M WhereM is a metal 0 0'1-15) Alumni ta candispersable in the vehicle. If the diamidocarboxylic acid or its salts are not soluble therein, at least in the percentage added, solubilizers may be added which bring this about; a suitable agentfor 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 non-mineral oils, such as animal, vegetable oils, fats, the synthetic polyesters of organic acids, polysiloxane, polyalkylene glycols, polyolefins, also the rustproof bases which may be used as the medium of application of rust preventive additive to the metal surface.

Some members of the lubricating oil base will be preferred for 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 such surfaces as machine parts, piston rings, machine guns, light arms, gears, turbine engines, and the moving parts of hydraulic baling machinery, or presses, metal drums, etc., will vary greatly.

Some members of this class of compounds, namely of the diamidocarboxylic acid additives, will be preferred for specific industrial applications, while other members will be preferred for other technical or industrial applications where the aim is to prevent rust formation. As to the selection of the additive, the conditions of use of the finished lubricant and/or the type of oleaginous vehicle will dictate or influence the selection. It can be mentioned that for use in turbine lubrication, the finished lubricant must permit ready separation of entrained water. It is essential for many reasons, which will not be elaborated upon, that water be easily separable from turbine lubricants by auxiliary oil purification equipment such as settling tanks, filters, blotter presses, centrifuges, etc.

The amount of corrosion inhibitor incorporated in the finished lubricating composition may be very small, amounts of the order of 0.0125%1%, based on the total finished oil lubricant, being sufiicient to secure metallic corrosion prevention, more particularly where the surface is ferrous in nature. Greater amounts may be added as dictated by particular requirements and EXAMPLE I (N-stearoyl)iminodiacetonitrile (36.1 grams) was dispersed in 170 milliliters of water at 65 to 70 C. containing 4.4 grams of sodium hydroxide. The temperature of the reaction mixture was gradually raised to 100 C. and maintained at this temperature for about 2% hours until substantially 0.1 mole of ammonia gas was evolved and swept out through the apparatus by a stream of But they are nitrogen gas. The reaction mixture was thencooled to 20 C. and neutralized with 6 N hydrochloric acid. A precipitate was formed, filtered and washed thoroughly with water. After drying, 40.0 gramsof a light tan powder were obtained. This melted at 134 to 139 C with decomposition and had a neutralization, value of 390. The neutralization equivalent Weight for (N- stearoyl) (N-carbamylmethyl)glycine is 398. Recrystallization from an isopropylacetate-methanol mixture yielded pure (N-stearoyl) (N-carbamylmethyl) glycine melting at 148 to 149 C. j

The product described in the example was tested for its rust preventive properties by dissolving it in asolvent --2,'7oo,veo v refined 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 after Example H.

EXAMPLE II 31.7 grams of (N-lauroyl)iminodiacetonitrile was dispersed in 250 milliliters of water containing 4.4 grams of sodium hydroxide warmed to 60 C. The reaction mixture was stirred and heated at C. for two hours and twenty-five minutes until substantially 0.1 mole. of evolved ammonia had been swept out of the reaction mixture by a stream of nitrogen gas. After cooling the reaction mixture to 30 C. it was made acid to pH 2.0 with 6 N sulfuric acid. The precipitate which formed was filtered, washed with water and dried to a constant weight of 32.5 grams. On recrystallization from ethyl alcohol the purified (N-lauroyl) (N-carbamylmethyl)- glycine melted at 148.5 to 149.5 C. It had a neutralization equivalent weight of 332. The theoretical neutralization equivalent weight of (N-lauroyl)(N-carbamy1- methyl)glycine is 314.

The respective products described in the example were tested for their rust preventive properties by dissolving each in a solvent-refined and filtered non-additive turbinegrade lubricating mineral oil of 150 Saybolt Universal Seconds viscosity at F. and subsequently testing these oil solutions by the Static Water Drop Corrosion Test described above. Briefly, the test consists essentially of observing rusting at F. in the presence of liquid water in the dimple of a triangular cold-rolled steel specimen immersed in the test oil. An effective rust preventive oil will prevent rusting for several days while straight mineral oils permit rusting to occur within 2 hours of test.

' solubilization of these diamidocarboxylic acids was effected by the addition of a solubilization agent which per se'in oil solution had little, if any, rust preventive properties. The agent used was Primene JMR, a commercially available primary, aliphatic amine, which has a tertiary-alkylamine structure, the tertiary groups having from 18 to 24 carbonatoms. It is marketed by Rohm and Haas Company. The results of these tests are given in Table I.

Table I.--Rust preventive properties of diamidocarboxylic acids in lubricating oil Wt. Wt. Per- Static Water Additive Example Percent cent Pri- Drop Corrosion (A) No. (A) (A) mene Test" Time to J MR 1 Rust (Hours) Base Oil None None Less than 16. Stearic Acid" 0. 20 None Do. Primene J MR 1 None 0.20 Do. stgiriifi Acid-d rimene 0.20 0. 20 Less than 2. (N -stearoyl) (N-carba- I 0.0125 v 0.0125 More than 200. mylmethyl) glycine. N-lauroyl) (N-carba- II 0.025 0. 025- More than 150.

. mylmethyl) glycine. I

1 "Primene J MR 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, t-Orr-zrHar-nNHr. It contains about 55-10% non-amine material. It is a non-viscous liquid, colorless to straw colored, insoluble in water and does not dissolve water to an appreciable extent. It exhibits solubility in hydrocarbon solvents and glyceride oils or fats, and in other organic liquids previously referred to under the term "oleaginous vehlcles'f. Additional physical properties are:

Refractive Index, 25 0 Boiling Point (or Range) Neutralization Equivalent 301. Flash Point (Tag, open cup). 250 F.

oior, Varnish Scale 4-.

It is evident that the rust preventive efiectiveness of answe s?) lubricating oil' solutions of the 'diamidocarboiiylieacids is much improvedover the base oil alone or solubilizer' in it. It "is also evident that the diamidocarboxylic' acids are qualitatively "superior: in "rust preventive effectiveness than a typical'high'molecular weight fatty acid such as stearic acid.

Having' disclos'cd the natureof '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 byjsai'd :Water, comprising an' oleaginous vehicle and 1a diamidocarboxylic vacid having the following empirical formula:

(CHDnCONH:

(GHQ-IO X where R1 represents an aliphatic carboxylic acid residue of C8-C24, where n and m each represents integers 1-2, and X represents hydrogen and groups capable of forming salts with the carboxylic acid group, said diamidocarboxylic acid being present in said oleaginous composition in minor amounts, as little as a fraction of 1% to amounts greater than 1% but in sufiicient quantity to inhibit corrosion of said metal to a great degree when compared to the check.

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

(CHQ'IC ONHa 1N\ (CHzh-C 0 OX where R1 represents an aliphatic carboxylic acid residue of Cit-C24, where n and m each represents integers 1-2, and X represents hydrogen and groups capable of forming salts with the carboxylic acid group, said diamidocarboxylic acid being present in said oil composition in minor amounts, as little as a fraction of 1% to amounts greater than 1% but in suflicient quantity to inhibit corrosion of said metal to a great degree when compared to the check.

3. A rust preventive oleaginous composition adapted for use in the presence of water, in systems containing metal susceptible of corrosion by said water, comprising an oleaginous vehicle and a diamidocarboxylic acid having :the following empirical formula:

where R1 represents an aliphatic carboxylic acid residue of Ca-C24, where n and m each represents integers 1-2, and X represents hydrogen and groups capable of forming salts with the carboxylic acid group, said diamidocarboxylic acid being present in said oleaginous composition in minor amounts, as little as a fraction of 1% to amounts greater than 1% but in sutficient quantity to inhibit corrosion of said metal to a great degree when compared to the check, and alkyl primary amines having 18-24 carbon atoms in sufficient amount to solubilize said diamidocarboxylic acid, in the oleaginous vehicle, the said alkyl amines being soluble in the oleaginous vehicle but insoluble in water.

4. A rust preventive oil composition adapted for use in the presence of water, in systems containing metal susceptible of corrosion by said water, comprising a a 6. hydrocarbon ,o'ilfanda diamidocarboxylic acidhaving the following empirical formula:

(OHsh-CONH! RiN (onmtooox where: R1 represents-an aliphatic carboxylic acid residue of Cs-C24, where n and in each represents integers -2, and X represents hydrogen and groups capable. of form? ing salts with the: carboxylicl acid group, said-diamidocarboxyl'ic acid being spresen t insaid oil composition in minor amounts, aslit'tle as a fraction of 1% to amounts greater than 1% but in suificient quantity to inhibitcorrosion oftsaid metal to .a great degree when compared to the check, and alkyl primary amines having 18-24 carbon atoms in suflicient amount to solubilize said diamidocarboxylic acid, in the hydrocarbon oil, the said alkyl amines being soluble in hydrocarbon oil but insoluble in water.

5. A rust-preventive oleaginous composition adapted for use in the presence of water, in systems containing metal susceptible of corrosion by said water, comprising an oleaginous vehicle and a minor amount of (N- stearoyl) (N-carbamylmethyl) glycine, as little as a fraction of 1% to amounts greater than 1% but in sufficient quantity to inhibit the corrosion of said metal to a great degree when compared with the check.

6. A rust-preventive oleaginous composition adapted for use in the presence of water, in systems containing metal susceptible of corrosion by said water, comprising an oleaginous vehicle and a minor amount of (N- lauroyl) (N-carbamylmethyl) glycine, as little as a fraction of 1% to amounts greater than 1% but in sufficient quantity to inhibit the corrosion of said metal to a great degree when compared with the check.

7. A rust-preventive oil composition adapted for use in the presence of Water, in systems containing metal susceptible of corrosion by said water, comprising a mineral oil and a minor amount of (N-stearoyl) (N- carbamylmethyl) glycine, as little as a fraction of 1% to amounts greater than 1%, but in sufiicient quantity to inhibit the corrosion of said metal to a great degree when compared with the check.

8. A rust-preventive composition adapted for use in the presence of water, in systems containing metal susceptible of corrosion by said water, comprising a mineral oil, a minor amount of (N-lauroyl) (N-carbamylmethyl) glycine, as little as a fraction of 1% to amounts greater than 1%, but in sufficient quantity to inhibit the corrosion of said metal to a great degree when compared with the check.

9. A rust preventive oleaginous composition adapted for use in the presence of water, in systems containing metal susceptible to corrosion by said water, comprising an oleaginous vehicle, a minor amount of (N-stearoyl) (N-oarb amylmethyl) glycine, as little as a fraction of 1% to amounts greater than 1% but in a sufiicient quantity to inhibit corrosion of said metal to a great degree as compared with the check, and alkyl primary amines having 18-24 carbon atoms in sufficient amount to solubilize said acyl (N-carbamylmethyl) glycine, in the oleaginous vehicle, the said alkyl amines being soluble in the oleaginous vehicle but insoluble in Water.

10. A rust preventive oleaginous composition adapted for use in the presence of water, in systems containing metal susceptible to corrosion by said water, comprising an oleaginous vehicle, a minor amount of (N-launoyl) (N-oarbamylmethyl) glycine, as little as a fraction of 1% to am'ounts greater than 1% but in a sufiicient quantity to inhibit corrosion of said metal to a great degree as compared with the check, and alkyl primary amines having 18-24 carbon atoms in sufiicient amount to s'olu bilize said acyl (N-carbamylmethyl) glycine, in the oleaginous vehicle, the said alkyl amines being soluble in the oleaginous vehicle but insoluble in water,

...7 11. -A rust preventive oil composition adapted for use in the presence of water, in systems containing metal susceptibl'e to corrosion by said water, comprising a mineral oil, a minor amount of (N-stearoyl) (N-carbamylmethyl) glycine, as little as a fraction of 1% to amounts greater than 1% but in a suificient quantity to inhibit corrosion of said metal toa great degree as compared with the check, and alkyl primary amines having 18-24 carbon atoms in sufl'icient amount to solubilize said acyl (N-carb amyl- 'methyl) glycine, in the mineral oil, the said alkyl amines being soluble in the mineral oil but insoluble in water. I 12. A rust preventive oil composition adapted for use in the presence of water, in systems containing metal susceptible to oorrosion by said water, comprising a mineral .Oil, a minor amount of (N-lauroyl) (N-carbamylmethyl) References Cited in the file ofthis patent UNITED STATES PATENTS CaIdwell Feb. 22, 1949 White et 1 Sept. 25, 1951 I it i;

Claims (1)

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