2,908,648 United States Patent Office Patented Oct. 13, 1959

1 2. this invention may be added to a wide variety of vehicles 2,908,648 to produce compositions having corrosion-inhibited prop CORROSION-INHIBITED coMPOSITIONS CON. erties, including acidic aqueous liquids, such as used in TAINING N-(ALKYLARYLSULFONYL) AMINO metal pickling solutions, to aqueous alcoholic solutions ACIDS AND SALTS THEREOF . . . . 5 both of the lower monohydric alcohol type and the poly John D. Spivack and Janet B. Peterson, Cranston, and hydric alcohol type, which solutions comprise the com Harry Kroll, Warwick, R.I., assignors to Geigy Chemi monly employed automobile radiator anti-freeze liquids. cal Corporation, New York, N.Y., a corporation of A great many materials have been proposed as coating Delaware compositions or as additives to lubricating oils for the 10 prevention of rust formation. In U.S. Letters Patent No. No Drawing. Application October 21, 1954 2,578,725 it is proposed to add various alkanesulfon - Serial No. 463,842 amidoalkane carboxylic acids of the general formula 12 Claims. (CI. 252-47.5) RSO. NH-RCOORs (wherein R is a saturated hy drocarbon of C12-C20, Ra is either aliphatic CHaiti or This invention relates to compositions having corrosion 15 inhibited, and especially rust-inhibited properties, which aryl or aromatic radicals and R3 is H or an alkali metal contain alkylarylsulfonyl derivatives. More particularly or ammonium) to alcohols, ketones and mixtures thereof. the present invention relates to organic compositions, es The alkanesulfonamidoalkane carboxylic acids used for pecially oleaginous compositions containing an alkylaryl that purpose are described in U.S. Patent No. 2,225,960 sulfonyl derivative, which compositions have the prop granted December 24, 1940. A specific example is hex erty of preventing or inhibiting corrosion and/or rusting, 20 adecanesulfonamidoacetic acid of the formula: especially in systems employing water or steam or which CHaSONH-CHCOOH may be contaminated with water or steam...... The compounds which we utilize as potent corrosive In various equipment in which water and/or steam is and/or rust inhibiting agents according to the present in used, or which may become contaminated with water or 25 vention are broadly alkylarylsulfonyl derivatives of an steam during service or storage, corrosion and/or rusting amino acid. The sulfonyl group is attached directly to of the metal parts, particularly the ferrous metal parts, is the aromatic nucleus. Those which are suitable for our encountered causing material damage to such equipment. purpose are alkylarylsulfonyl amino acids having the em The prevention of rust formation is particularly impor pirical formula: tant in the protection of metal surfaces where such sur 30 faces are to be lubricated in the presence of moisture. . Moisture may enter lubricating systems of land or marine R-ArtsNCH).cHoooy2 turbines, for example, by leakage through steam glands O R. and through water-cooled heat exchangers or by con densation from the atmosphere. The presence of rust is 35 wherein R represents one or two alkyl groups of 8-24 injurious because it causes excessive wear of gears and carbon atoms inclusive; Ar represents an aryl group. bearing surfaces, and may also clog the hydraulic gover which may be phenyl, naphthyi, arithracyl, phenanthryl, nor system, leading to dangerous operating speeds. Fur chrysyl (Beilstein, vol. V, p. 718), etc.; R represents a thermore, the presence of rust has been shown to increase substituent selected from the group consisting of hydro the rate of oxidative breakdown of the lubricant itself. 40 gen, alkyl, hydroxyalkyl, carboxyalkyl and phenyl; R. The present invention is also applicable to anti-rust-or represents a substituent selected from the group consist slushing compositions employed for the protection of : ing of hydrogen, alkyl and carboxyalkyl; in represents 0,1 metals against atmospheric corrosion and/or rtisting. or 2; Y represents hydrogen or a salt forming group. Such compositions are applied to metallic articles, includ The above type compounds are added to a liquid or ing fabricated metallic articles, and finished or semi-fin semi-solid vehicle in a quantity sufficient to confer cor ished metal stock to be stored or for shipment by rail rosion and/or rust prevention to the composition which or water, to preventrusting and/or corrosion thereof. otherwise tends to permit corrosion of metal when brought The aim in the use of protective or slushing compositions in surface contact therewith. is to protect objects against attack by moisture by...coat More particularly and important we have found that ing them. ; - , the corrosive effect of lubricating oils and greases important industrial applications of the corrosion 50 (oleaginous vehicle) upon bearing surfaces, gears and and/or rust preventing compounds. of the present inven- is, other metallic parts in the presence of water or steam, tion vary over a wide range. They afford excellent pro may be prevented by the incorporation in said oleaginous tection when incorporated into the following lubricating vehicle of a small amount of a class of compounds which oils and dielectric oils: motor oils, diesel oils, aviation 55 are alkylarylsulfonyl derivatives of amino acids, whose engine oils, marine engine lubricants, gear oils, oil field empirical formula has been given in the preceding para machinery lubricants, ice-machine oils, steam cylinder : graph. Stich compounds, when used in small amounts in lubricants, transmission oils, soluble oils, textile oils, cut oleaginous vehicles, it has been determined by scientifi ting oils both soluble containing water and the straight cally acceptable tests and by other means, effectively pre oils, turbine oils, insulating. oils; lubricating greases: yent, the rusting, of metal surfaces, particularly those of stable gel-like or solid dispersions of metal soaps in hy 60 ferrous metal, upon exposure to water or steam. These drocarbon oils; protective coatings; preservative com: - additives; moreover, prevent rusting without influe pounds, slushing oils, and greases in which part or all of other properties of the lubricant disadvantageously. the hydrocarbon oil may be replaced by metal soaps and . The members of this: class of corrosion other constituents; flushing oils. These have vehicles agents may be regarded as derivatives of the which would be classed in whole or part as oleaginous... 65 synthetic amino acids, for example, of glycine, who The alkylarylsulfonyl amino acids and their salts of structural formula is NHCHCOOH, or and B alanine, 2,908,648 ...... 4. the structural formula of which are CHCH(NH2)COOH or nitrile conforming to the second respective reactant and CH(NH) CHCOOH a respectively, sarcosine or in the empirical formula set forth in equations of proc methyl glycocoll, whose structural formula is esses (A), (B) and (C), and the pure chlorocarboxylic acid salt which is the second reactant in the process of CHNHCHCOOH equation D. Or the reactants may be mixtures result iminodiacetic acid, whose structural formula is ing in a product consisting of a mixture of compounds, HOCOCH-NH-CHCOOH all represented by the formula aspartic acid whose structural formula is R-Ar-SONR(CH,),CHCOOY O - HOCO-CH(NH,)CHCOOH the symbols in which are defined above. glutamic acid whose structural formula is In further explanation, it may be stated that the R-Ar grouping set forth above may be derived from straight Hoc-HCH)-cooh chain or branched-chain octyl, decyl, dodecyl, tetradecyl, NH hexadecyl, or octadecyl derivatives of either benzene, Non-limiting examples of the new type of compounds 5 naphthalene, anthacene or chrysene or from mixtures which are useful as rust and/or corrosion preventives are: thereof. The R-Ar grouping may also be derived from N-(dodecylbenzenesulfonyl) glycine, N-(dodecylbenzene the reduction of fatty acylated or alkenylated aromatic sulfonyl) sarcosine, N-(dodecylbenzenesulfonyl) iminodi compounds. The products obtained by processes (B) acetic acid, N-(dodecylbenzenesulfonyl) glutamic acid, and (C) outlined above may also have more or less N-(dodecylbenzenesulfonyl) alanine, N-(dinonylnaph 20 unsaponified ester or nitrile groupings present therein in thalenesulfonyl)glycine, N-(dinonylnaphthalenesulfonyl) addition to free carboxyl groups or salts thereof. sarcosine, N-(dinonylnaphthalenesulfonyl)-iminodiacetic One of the major uses of the additives of the present acid, N-(dinonylnaphthalenesulfonyl) glutamic acid, N invention is in the industrial field of lubrication of metal (dinonylnaphthalenesulfonyl) alanine, N-(octadecyl an surfaces employing both oils and greases. Another use thracenesulfonyl)-sarcosine, N-(octylxylyl) sarcosine and 25 is the protection of metals, such as iron or broader the the like. ferrous type metal, in humid atmospheres by preservative The sulfonylated amino acids of the general type of oils and slushing oils or greases. The members of the the corrosion preventative -agents of our invention can class of compounds of this invention can be used alone be prepared in a number of ways, for example, as out in an oleaginous vehicle or solvent. Used thus these ad lined in Equations A, B, C and D below: 30 ditives which function as corrosion inhibitors, may be used in a variety of physical states, e.g., as a dispersion, (A) i. emulsion or solution. When employed in an oleaginous R-Ar-SOC - RNHCCH)-6HCOONa - vehicle, the compounds should be soluble, miscible or alkali dispersible in said vehicle. It should be noted that the R-Ar-SO2NR(CH) thcooNa 35 term "oleaginous vehicle' is employed in the broader Rs sense and to include hydrocarbon oils, fatty oils, fats, the synthetic lubricants such as those of the polyester, poly aelanation siloxane, polyalkylene glycols and polyolefine types, and R-At-so-NR(CH). Hoooh 40 rustproof bases, etc., which may be used as the medium R2 of application of rust-preventive additive to the metal surface. - ...... I , The N-(alkylarylsulfonyl) amino acids may be incor (B) - R porated in the oleaginous vehicle in varying proportions being governed by specific use to which the rust preven R-Ar-SOC) + RiNHCCH)-CHCooch, - 45 tive composition is to be put, the degree of rust preven - R-A-soNR(CH). Hooooh, --> . I tion desired, as well as economic considerations, and on R (1 the specific alkylarylsulfonyl amino acid selected. Gen Saponification erally it is sufficient to use an amount between 0.005 and 8 Acidification 10% by weight, although greater or lesser amounts may (C) R - 50 be used. - R-Ar-SOCl - RNHCCH)-CHICEN - - - - - As indicated supra, the general type of alkylarylsul fonyl amino acids and their salts, which are the corrosion - R-Ar-so-NR. H.)..CHC=N inhibitors of the present inventors, are believed to have . .R. been first prepared by the present inventors. For that Saponification 55 reason the synthesis of several of these additives by vari 3 SE:cidification - ous modes will be described in detail in the subsequent R-Ar-SONR(CH) CHCOOH examples which appear in order of arrangement before 2 the rust tests and emulsion tests. (D) -: , , . . . 60 EXAMPLES OF OUR CORROSION INHIBITORS R-Ar-SONH- Cicon)- Hooona - . : Example 1 of corrosion inhibitor- . . . . R...... N-(n-dodecylbenzenesulfonyl) sarcosine . . . . . R-Ar-soNR(CH)-HcooNa (A) AND (B) PREPARATION OF N-DoDECYL 65 Seventy-fourBENZENESULFONYL grams (74.g.). (0.30 CHLoRIDE mole) of .n-dodecyl . . . benzene (N5 -1.483, boiling at 4.2 mm. Hgpressure at Aclanation 165-170° C.) was dissolved in 200 milliliters of methyl R-Ar-son Riccip-Hoooh. ene chloride in a 1-liter flask fitted with a mechanical ‘...... R. 70 stirrer, an air condenser, thermometer and dropping The reactants in the process of manufacture may be funnel; the entire apparatus was protected from moisture relatively pure single compounds, for example, pure by calcium chloride drying tubes on the condenser and alkylarylsulfonyl chloride or the sulfonyl amides (see: the dropping funnel. The solution was cooled to 10° C. empirical formula of respective first mentioned reactant by an external bath. Chlorsulfonic acid (73.g.) (0.63 in Equations A and D), and pure amino acid salt, ester, 5 mole) was added thereto over a period of 35 to 40 2,908,848 5 minutes while its temperature was kept at -10° C. to dioxane was added dropwise to the reaction mixture -7 C. The reaction mixture became dark brown in while undergoing stirring, over a period of 25 minutes, color. It was stirred and additional two hours while and this mixture was stirred at room temperature for an maintaining its temperature at 0° C., followed by two hour; it was then heated at reflux for an additional hour. more hours at 20° C., whereupon it was let stand at room The chloroform solution of the reaction product was temperature overnight, i.e., for about fifteen hours. The washed successively with water and 5% aqueous sodium reaction mixture was poured into 300 grams of ice, and chloride solution, and then dried over anhydrous sodium 300 milliliters of diethyl ether were added, intimately sulfate. It was then decanted from the drying agent. mixed therewith, whereupon after stratification the water The residue, after evaporation of chloroform was heated layer was separated from the upper or ether layer. The O on a steam bath with 100 milliliters of 1 N sodium water layer was extracted with an additional 300 mil hydroxide solution in water for two hours. The product liliters of ether. The combined ether extracts were ex was the sodium salt of N-(n-dodecylbenzenesulfonyl) tracted with 300 milliliters of a 5% aqueous solution of iminodiacetic acid in solution. The alkaline solution was sodium bicarbonate also containing 10% by weight of extracted with 100 milliliters of ether to remove un sodium chloride to remove residual inorganic acids. The 5 saponified material. The aqueous solution was then ether in the purified ether layer was removed by distilla made acid to pH 1 and extracted with 150 milliliters of tion at atmospheric pressure followed by reduced pres ether, after which the ether layer was separated and dried sure. The residue was taken up in 500 milliliters of over anhydrous sodium sulfate. After separation from acetone and filtered free of inorganic salts. Analysis of the dehydrating agent, ether was distilled off. The residue the residue (A) from the acetone distillation indicated 20 from ether solution, amounting to 9.36 grams, was re that product (A) contained about 8.3% of n-dodecyl crystallized from 5:1 hexane-ethyl acetate solvent and benzene-sulfonyl chloride, the remainder being n-dodecyl yielded white crystals melting at 146-147 C. benzene sulfonic acid. - Potentiometric titration with 0.10 N methanolic po Phosphorus pentachloride (19.3 grams) was added tassium hydroxide of the sample dissolved in dimethyl gradually with occasional shaking to product (A) 25 formamide, calculated neutralization equivalent weight amounting to 28 grams, in an Erlenmeyer flask fitted for CHONS, N-(n-dodecylbenzenesulfonyl)iminodi with a drying tube. After effervescence stopped, the re acetic acid, first end point -441; second end point action mixture was warmed on a water bath for about 30 -220.5; found, first end point -449; found, second end minutes. The product was then poured into ice, and point -219.5. extracted with 200 milliliters of ether. The ether extract 30 was thereupon washed with water and then dried over Example. 3 of corrosion inhibitor-(N-dodecyl anhydrous sodium sulfate. After being separated, ether benzenesulfonyl) sarcosine technical was removed by evaporation. The residue, which was (A) PREPARATION OF DODECYLBENZENESULFONYL product (B), was a viscous, reddish oil, the analysis of CELORIDE which indicated that it consisted of 96%-97% of n 35 This compound was prepared in the following manner dodecylbenzenesulfonyl chloride. from a commercial grade of dodecylbenzene. (C) PREPARATION OF N-(n-DODECYLBENZENESULFO One-half mole of dodecylbenzene (123 grams) was NYL) sARCOSINE FROM PRODUCT (B) suPRA. dissolved in 200 milliliters of methylene chloride in a Sarcosine (3.6 grams) (0.041 mole) was dissolved in 1-liter. flask fitted with a mechanical stirrer, an air-con 41 milliliters of 1.0 N solution of sodium hydroxide in 40 denser, thermometer and dropping funnel; the entire water to form its sodium salt, and cooled to 15 C. A apparatus was protected from moisture by calcium chlo dioxane solution on n-dodecylbenzenesulfonyl: chloride ride drying tubes on the condenser and dropping funnel. (14.0 grams of product (B) described above dissolved in After cooling the methylene, chloride solution to -8 C. 50 milliliters of dioxane) and 41 milliliters of 1.0° N by an external bath, chlorsulfonic acid (145.5 g.) (1.2 aqueous sodium hydroxide were added dropwise simul 45 moles) was added thereto, dropwise, over a period of taneously to the aqueous sarcosine solution of the sodium one hour and fifty minutes while the temperature of the salt of sarcosine over a period of 20 minutes. The re reaction mixture was maintained between -9 and -2 action mixture was stirred an additional two hours at C. The reaction mixture became increasingly dark brown room temperature; this contained the sodium salt of N in color as the addition of chlorsulfonic acid proceeded. (n-dodecylbenzenesulfonyl) sarcosine with by-products 50 It was stirred an additional two hours while maintaining of the reaction. It was then made acid to pH 2 with 6 N its temperature at 0° C., whereupon it was allowed to aqueous hydrochloric acid, after which it was extracted stand at room temperature for about 16 hours. It was with ether. This extract was heated to distill off the then poured into a mixture of 500 milliliters of 15% ether. The residue (12.8 grams) was crystallized from aqueous sodium chloride and about 300 grams of ice, n-hexane, and there was obtained a white crystalline 55 and stirred well. Diethyl ether in an amount of 300 product. melting at 110-111° C. (uncorrected). The inililiters was added, and intimately mixed with the reac crystalline product was substantially pure N-(n-dodecyl tion-mixture, whereupon after stratification the upper or benzenesulfonyl) sarcosine having a neutralization ganic layer was separated and washed with several 75 equivalent weight of 400. The calculated neutraliza milliliter portions of water containing 5% sodium bi tion equivalent weight for N-(n-dodecylbenzenesulfonyl) 60 carbonate and 10% sodium chloride. The ether-methyl sarcosine is 397...... '-- ene chloridesolution was dried over solid anhydrous sodi um sulfate overnight, separated from the latter, after Example 2 of corrosion inhibitor-N-(n-dodecyl which the organic solvent mixture was removed by dis benzenesulfonyl) iminodiacetic acid tillation. The residue was a dark brown liquid, insoluble 65 in water; it weighed 120 grams. The yield of crude prod Dimethyliminodiacetate hydrochloride. (7.7 grams) uct was therefore about 70% of theory. (0.039 mole), was dissolved in 100 milliliters of chloro Analysis of the crude sulfonyl chloride gave the fol form contained in a 300 milliliter capacity flask which lowing results: - was fitted with a condenser, stirrer and dropping funnel . . . Wt. percent suitably fitted with calcium chloride drying tubes to 70 protect the reaction mixture from moisture. Triethyl Dodecylbenzenesulfonylchloride------87.1 amine (8.2 grams) (0.082 mole) was added all at once, Dodecylbenzenesulfonic acid------14.8. and the reaction mixture cooled to room temperature. A dioxane solution of n-dodecylbenzenesulfonyl chloride The analytical results indicated that the product as (14 grams). (0.04.1 mole) dissolved in 50-milliliters of 75 thedescribed next example. above could be used as a reactant in this and 2,908,648 27 8 (B) PREPARATION OF N-DODECYLBENZENESULFONYL and warmed on the steam bath for one hour with oc sARCOSINE FROM PRODUCT (A) suPRA casional stirring. The reaction solution of the potassium Nine and two-tenths. grams (9.2 g.). (0.10 mole) of salt of (N-dodecylbenzenesulfonyl)iminodiacetic acid was sarcosince which was 96.6% pure was dissolved in 100 diluted with an equal volume of water, made acid to pH1 milliliters of water containing 4.1 grams (0.10 mole) of with 6.N. aqueous hydrochloric acid and extracted with sodium hydroxide. Dodecylbenzenesulfonyl chloride de two 200 milliliter portions of ether. The ether solution scribed in (A) above (39.2 grams) (0.10 mole) was dis of the free (N-dodecylbenzenesulfonyl)iminodiacetic acid solved in dioxane so that a volume of 70 milliliters was was then dried over anhydrous sodium sulfate. After de obtained. The dioxane solution of it and 70 milliliters cantation from the drying agent the ether was distilled of aqueous alkali (containing 4.7 grams of sodium hy 10 off. The residue from ether weighed 32.9 grams and had droxide) were added simultaneously to the stirred Sar a neutralization equivalent of 415. The theoretical neu cosine solution over a period of 30 minutes, the tempera tralization equivalent for (N-dodecylbenzenesulfonyl) ture of the reaction varying from 28°C. to 37 C. The iminodiacetic acid is 220.5 indicating that the product is reaction mixture was stirred at 45 C. for one hour and a mixture of (N-dodecylbenzenesulfonyl)iminodiacetic then let stand at room temperature for about sixteen 15 acid and its methyl esters. hours. This contained the sodium salt of N-dodecyl . In order to demonstrate the outstanding properties of benzenesulfonyl chloride sacrosine-technical. It was then the N-(alkylarylsulfonyl) amino acids and their salts, made acid to pH 3 with 6 N aqueous hydrochloric acid which are the corrosion inhibitors of the present invention, after which it was extracted with two 200 milliliter por rust test data and emulsion test data were obtained for tions of diethyl ether. The ether layer was dried over a selected mineral oil containing the respective products anhydrous sodium sulfate. After this dehydration step synthesized in Examples 1, 2, 3, 4 and 5 described above. and separation from the sodium sulfate, ether was re . The oil used in these was a solvent-refined and filtered moved by distillation. The residue was an amber-like non-additive turbine-grade lubricating mineral oil of 150 gummy mass having a neutralization equivalent of 485. Saybolt Universal Seconds viscosity at 100 F. The theoretical neutralization equivalent for N-(dodecyl 25 The rust test which was selected because it has been benzenesulfonyl) sarcosine is 397. The reaction product widely used was the "Static Water Drop Corrosion Test' thus has an analysis which varies quite appreciably from developed by Zisman et al. and described in “Industrial that expected for (N-dodecylbenzenesulfonyl) sarcosine. and Engineering Chemistry," vol. 41, page 137 ff. (1949). Briefly, the test consists essentially of observing rusting at 30 140 F. in the presence of liquid water in the dimple of Example 4 of corrosion inhibitor-Reaction product of a triangular cold-rolled steel specimen immersed in the technical dodecylbenzenesulfonyl chloride with imino test oil. An effective rust preventive oil will prevent diacetic acid . rusting for several days while straight mineral oils permit Iminodiacetic acid (2 g.) (0.015 mole) and triethyl rusting to occur within2 hours, of test. . amine (4.55 g.) (0.045 mole) were mixed in boiling 35 - Solubilization of these N-(alkylarylsulfonyl) amino chloroform, and after cooling to room temperature the acids of these examples was effected by the addition of 90% dodecylbenzenesulfonyl chloride, prepared by Ex a solubilization agent which per se in oil solution had ample 3(A) supra, in an amount of 5.15 grams (0.01.05 little, if any, rust preventive properties. The specific mole) was added. The mixture was shaken vigorously for agent used was a commercially available tertiary alkyl 20 minutes, then allowed to stand at room temperature 40 primary amine, the tertiary alkyl groups having from overnight (about 16 hours). It was then refluxed for 18 to 24 carbon atoms, known as “Primene JMR, which an hour before filtering the insoluble material. The is described more exactly in a footnote in Table I. chloroform was removed by distillation in vacuo. The The test used for determining the demulsibility proper residue, which represented the triethylamine salt of tech ties of lubricating oils is to be found in the Federal Stand nical (N-dodecylbenzenesulfonyl)iminodiacetic acid, was 45 ard Stock Catalogue method 320.1.5 dated November 15, acidified to pH 1 with aqueous 6 N hydrochloric acid 1948, and entitled "Emulsion (Lubricating Oils).” Briefly, after which the solution was extracted several times with this test involves mixing 40 milliliters of water and 40 ether. The ether extracts were washed with dilute hydro milliliters of test oil at 130 F. or 180° F. under stand chloric acid and water and thereafter dried over anhy ard conditions and observing the separation of oil and drous sodium sulfate. After decantation from the de 50 water phases at the test temperature. The test tempera hydrating agent, the ether was removed by distillation. ture selected is usually 130 F. for light viscosity turbine The residue was an amber colored, semi-hardened mass, oils up to about 500 Saybolt Universal seconds viscosity weighing 1.4 grams. It has a neutralization equivalent of at 100 F., and that was the temperature which was 548. The reaction product thus has an analysis which selected for the tests reported. The figures in the table varies quite appreciably from that expected for (N-do 55 show the number of minutes at which there is no con decylbenzenesulfonyl) iminodiacetic acid. tinuous layer of emulsion between the oil and the emul Sant (water). . The U.S. Navy specifies that 2190-T grade Example 5 of corrosion inhibitor-Reaction product of turbine oils separate from water in this test within thirty dodecylbenzenesulfonyl chloride with dimethylimino minutes and have not more than 3 milliliters of an inter diacetate hydrochloride 60 mediate oil-and-water phase at this time in order to com Dimethyliminodiacetate hydrochloride (20.0 grams) ply with MIL-L-17331 - (Ships) Specification of Septem (0.10 mole) was dispersed in 200 milliliters of chloro ber 30, 1952. This criterion of demulsibility is widely form, and 24.3 grams of triethylamine (0.24 mole) was adopted by turbine oil producers and consumers. added rapidly while the chloroform dispersion was stirred. For comparison, in order to determine quantitatively Dodecylbenzenesulfonyl chloride was dissolved in 125 65 milliliters of chloroform and added dropwise over a period the effect of other additives to the mineral lubricating oil, of one hour to the stirred chloroform solution of dimethyl both on rust prevention and imparting different emulsifi iminodiacetate. The turbid reaction mixture was stirred cation characteristics, the corrosion test and the emulsion at room temperature for an additional hour, then washed test were run on the base oil as a check, the tertiary successively with water and 5 percent aqueous sodium 70 alkylprimary amine. (2 concentrations) in the oil, stearic chloride solution, after which the chloroform solution was acid in the oil, and mixture of stearic acid with the ter dried over anhydrous sodium sulfate. After separation tiary-alkyl primary amine in the oil, as well as the oil con from the sodium sulfate the chloroform was distilled. taining the investigated N-(alkylarylsulfonyl)amino acids The residue was dissolved in 300 milliliters of 50% aque in the compositions given in the appended table. ous methanol containing 17 grams of potassium hydroxide 5 : The pertinent test results are set forth in Table I. 2,908,648 9 10 TABLEI.-RUST PREVENTIVE AND DEMULSIBILITYACIDSNLUBRICATING PROPERTIES OIL OF (N-ALKYLARYLSULFONYL)AMINO

Emulsion Wit. per- Test Time Static Water Wt, per- cent of for Com- Drop -Corrosion Additive (X). of (X) 'Primene plete Sepa- Test' Time to JM.R.' ration Rust (Hours) (Minutes)

Base Oil------Primene.J.M.R. 1 - 10 : Less than 16. 'Primene J.M.R.' ------Do. Stearic Acid.------10 Stearic Acid and “Primene JMR' - - Do. N-(n-dodecylbenzenesulfonyl) sarcosine -- - Less than 2. N-(n-dodecylbenzenesulfonyl)iminodiacetic acid - More than 300 hrs. m ------Do. 15 D0. (N"geylbenzenesulfonylsarcosine0------(technical)-- - - H Reaction Product of technical dodecylbenzenesulfonyl IV 5 Do. chigade and iminodiacetic acid. IW 0 Do. 0------6 Do. (N-secylbenzenesulfonyl)iminodiacetic acid (technical) W 6 DO. 0------12 Do. i 'Primene JMR' is a mixture of branched, primary amines in which the primary amino nitrogen group is directly attached to a tertiary carbon atom, and being composed of amines from eighteen to twenty-four carbon atoms; the predominantportion may be byrepresented Rohm & byHaas the Companyformulat=Cs2H of Philadelphia, NEI. Pennsylvania. It contains about 8-10% non-amine material. This trademarked productis marketed From the data set forth in this table it is apparent anti-freezes include water, water-alcohol, glycols, glycol that a much improved rust preventive effectiveness is im Water, etc. parted to lubricating oil which contains the N-(alkylaryl Other substances in addition to the reaction products, sulfonyl) amino acids of the present invention, whether the corrosion inhibitors of this invention can be added the comparison is made on the base oil alone or with the to compositions contemplated herein to impart other de solubilizer in the oil. It is also evident that the N-(alkyl sirable properties thereto, such as anti-oxidants, pour arylsulfonyl)amino acids are qualitatively superior in rust 30 point depressants, V.I. improvers, etc. - preventive effectiveness than a typical high molecular Some members of this class of compounds will be weight fatty acid, such as stearic acid, or the latter ad preferred for specific applications while other members mixed with the identical solubilizer. will be preferred for other applications where, rust pre It is apparent from the emulsion test data given in the vention is desired. Some members of this class of com table that the alkylarylsulfonyl amino acids tested do not 35 pounds are particularly applicable for turbine lubrication, impart undesirable emulsion characteristics to the tur because lubricant compositions containing them permit bine oil. - , ready separation of entrained water. It is essential that The vehicle can be aqueous which includes aqueous so water be easily separable from turbine lubricants by lutions of liquids, such as alcohol-water mixtures, or the auxiliary oil purification equipment such as settling tanks, like. Non-limiting examples of suitable vehicles for the 40 filters, blotter presses, centrifuges, etc., because water corrosive inhibitor additives of this invention are mineral in addition to causing rusting accelerates oil breakdown, lubricating oils of all grades; gasolines and other light causes excessive foaming and facilitates the dispersion petroleum products, such as fuel oil; water, alcohols, such of other contaminants which accelerate oil breakdown as ethanol, isopropanol, butanol, cyclohexanol, methyl and are injurious to the lubricating system in other ways. cyclohexanol, octanol, decanol, dodecanol, hexadecanol, 45 Although the present invention has been described with octadecanol, roleyl alcohol, benzyl alcohol, etc.; glycols, preferred embodiments, it is to be understood that modi such as ethylene glycol, propylene glycol, butylene glycol; fications may be made without departing from the spirit glycerol, etc.; ketones, such as acetone, -methyl ethyl ke and scope thereof, as those skillied will readily understand. tone, dipropyl ketone, cyclohexanone, etc.; keto alcohols, Such variations and modifications are considered to be such as benzoin; ethers, such as diethyl ether, dipropyl within the purview and scope of the appended clainis. ether, dichloro diethyl ether, diphenyl oxide, polyethylene We claim as our invention: glycols as diethylene glycol and triethylene glycol, ethyl 1. A corrosion-inhibiting composition which comprises ene glycol monobutyl ether, etc.; neutral esters, such as a liquid vehicle which tends to permit the corrosion of ethyl acetate, butyl propionate, cresyl acetate, dodecyl metal in the service to which said vehicle is put, con acetate, ethyl maleate, butyl stearate, tridecyl phosphate, 55 taining a member selected from the group consisting of tributyl trithiophosphate, triamyl phosphite, dibutyl seba N-(n-dodecylbenzenesulfonyl) sarcosine and N-(n-dodec cate and dioctyl sebacate, etc.; petroleum waxes, such as ylbenzenesulfonyl) iminoacetic acid, said member being slack wax and paraffin wax; natural waxes, such as car present in said liquid vehicle in amounts of as little as nauba wax, japan wax, beeswax, etc.; natural fats and oils, a fraction of 1% by weight but in a sufficient quantity such as sperm oil, tallow, cottonseed oil, castor oil, lin 60 to inhibit corrosion of said vehicle. seed oil, tung oil, soybean oil, oiticica oil, tar oil, oleo 2. A corrosion-inhibiting composition which comprises oil, etc.; hydrocarbons; greases; asphalts; and chlorinated a liquid vehicle which tends to permit the corrosion of petroleum fractions, such as chlorowax. metal in the service to which said vehicle is put, con The order of amount of corrosive inhibitor additive taining N-(n-dodecylbenzenesulfonyl) sarcosine, said lat used in these various vehicles is like that which has been 65 ter component being present in said liquid vehicle in set out previously as to oleaginous vehicles. amounts of as little as a fraction of 1% by weight but Acidic aqueous solutions for metal pickling baths can in a sufficient quantity to inhibit corrosion of said metal. be protected against corrosive tendencies by employing 3. A corrosion inhibiting composition which comprises our corrosion inhibitors. Hydraulic systems can be pro a liquid vehicle which tends to permit the corrosion of tected against corrosion by using hydraulic fluids con 70 metal in the service to which said vehicle is put, con taining additives of the present invention. Corrosive taining N-(n-dodecylbenzenesulfonyl) iminodiacetic acid, tendencies of coolants and anti-freeze solutions or mix said latter component being present in said liquid vehicle tures, such as those used as coolants in internal com in amounts of as little as a fraction of 1% by weight but bustion engines, can be reduced by addition thereto of in a sufficient quantity to inhibit corrosion of said metal. the alkylarylsulfonyl amino acids of our invention. Such 5 4. A rust-inhibited oleaginous composition adapted for

2,908,648 1. 2 use in the presence of water in systems containing metal metal, and an alkyl primary amine having 18-24 carbon susceptible to corrosion by said water, comprising an atoms in sufficient amount to solubilize said N-(n-dodecyl oleaginous vehicle and a member selected from the group benzenesulfonyl) iminodiacetic acid. ------consisting of N-(n-dodecylbenzenesulfonyl) sarcosine 10. A rust-inhibited oleaginous composition adapted and N-(n-dodecylbenzenesulfonyl) iminoacetic acid, said 5 for use in the presence of water in systems containing member being present in said oleaginous vehicle in metal susceptible to corrosion by said water, comprising amounts of as little as a fraction of 1% by weight but an oleaginous vehicle, a member selected from the group in a sufficient quantity to inhibit corrosion of said vehicle. . consisting of N-(n-dodecylbenzenesulfonyl) sarcosine 5. A rust-inhibited oleaginous composition adapted for-- and N-(n-dodecylbenzenesulfonyl) iminoacetic acid in use in the presence of water in systems containing metal 10 amounts to between substantially 0.005% to about 10% susceptible to corrosion by said water comprising an by weight, and an alkyl primary amine having 18-24 oleaginous vehicle and N-(n-dedocylbenzenesulfonyl) carbon atoms in sufficient amount to solubilize said mem sarcosine, said latter component being present in said ber in the oleaginous vehicle. oleaginous vehicle in amounts of as little as a fraction 11. A rust-inhibited oleaginous composition adapted of 1% by weight but in a sufficient quantity to inhibit 5 for use in the presence of water in systems containing corrosion of said metal. metal susceptible to corrosion by said water, comprising 6. A rust-inhibited oleaginous composition adapted for an oleaginous vehicle, N-(n-dodecylbenzenesulfonyl) sar use in the presence of water in systems containing metal cosine in amounts between substantially 0.005% to about susceptible to corrosion by said water comprising an 10% by weight, and an alkyl primary amine having oleaginous vehicle and N-(n-dodecylbenzenesulfonyl) 20 18-24 carbon atoms in sufficient amount to solubilize iminodiacetic acid, said latter component being present said N-(n-dodecylbenzenesulfonyl) sarcosine in the oleag in said oleaginous vehicle in amounts of as little as a inous vehicle. fraction of 1% by weight but in a sufficient quantity to 12. A rust-inhibited oleaginous composition adapted inhibit corrosion of said metal. . for use in the presence of water in systems containing 7. A rust-inhibited oleaginous composition adapted for 25 metal susceptible to corrosion by said water, comprising use in the presence of water in systems containing metal an oleaginous vehicle, N-(n-dodecylbenzenesulfonyl)im susceptible to corrosion by said water, comprising an inodiacetic acid in amounts between substantially 0.005% oleaginous vehicle, a member selected from the group to about 10% by weight, and an alkyl primary amine consisting of N-(n-dodecylbenzenesulfonyl) sarcosine and having 18-24 carbon atoms in sufficient amount to solu N - (n - dodecylbenzenesulfonyl) iminoacetic acid in 30 bilize said N-(n-dodecylbenzenesulfonyl) iminodiacetic amounts of as little as a fraction of 1% but in sufficient acid. quantity to inhibit corrosion of said metal, and an alkyl primary amine having 18-24 carbon atoms in sufficient References Cited in the file of this patent amount to solubilize said member in the oleaginous UNITED STATES PATENTS vehicle. 35 8. A rust-inhibited oleaginous composition adapted for 2,142,847 Hultquist ------Jan. 3, 1939 use in the presence of water in systems containing metal 2,225,960 Orthner et al. ------Dec. 24, 1940 susceptible to corrosion by said water, comprising an 2,578,725 Michel et al. ------Dec. 18, 1951 oleaginous vehicle, N-(n-dodecylbenzenesulfonyl) sarco 2,602,760 Michel et al. ------July 8, 1952 sine in amounts of as little as a fraction of 1% but in 40 2,656,381 Sprague ------Oct. 20, 1953 sufficient quantity to inhibit corrosion of said metal, 2,660,562 Axe et al. ------Nov. 24, 1953 and an alkyl primary amine having 18-24 carbon atoms 2,692,857 Michel et al. ------Oct. 26, 1954 in sufficient amount to solubilize said N-(n-dodecylben 2,694,045 Jones et al. ------Nov. 9, 1954 Zenesulfonyl) sarcosine in the oleaginous vehicle. 2,704,264 Michel et al.------Mar. 15, 1955 9. A rust-inhibited oleaginous composition adapted for FOREIGN PATENTS use in the presence of water in systems containing metal 900,041 Germany------Dec. 17, 1953 susceptible to corrosion by said water, comprising an oleaginous vehicle, N-(n-dodecylbenzenesulfonyl) imino OTHER REFERENCES diacetic acid in amounts of as little as a fraction of 1% Tertiary-alkyl Primary Amines, Rohm & Haas, Septem but in sufficient quantity to inhibit corrosion of said ber 1954, pp. 16 and 17.