US2451874A - Corrosion inhibiting composition - Google Patents

Description

Patented Oct. 19, 1948 2,451,874 r bRROSION INHIBITING COMPOSITION Willis G. Routson, Berkeley, Calif., assiznor to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. Application June 28, 1944, Serial N0. 542,613

21 Claims.

The present invention relates to metals or metal-cont-aining articles of manufacture which'are normally subject to corrosion and which have been rendered substantially non-corrodible by treatment with certain organic ,sulfones in a suitable vehicle. It also relates to compositions having anti-corrosive, and especially rust-protective properties, and more particularly deals with compositions comprising a substantially neutral vehicle such as normally liquid or normally solid hydrocarbons (e. g., fatty oils and natural waxes),

. alcohols, ethers, water, etc., containing finely dispersed small amounts of such organic sulfonyl compounds.

Metallic surfaces, particularly those containing iron, require protection against the hazard of corrosion in the presence of water. To illustrate: Moisture readily attacks finished or semi-finished metal objects unless the metal surface is covered during storage or shipment by a protective coating such as is imparted by a. slushing oil; water in Diesel engine fuels often corrodes closely fitted parts such as are found in Diesel engine unit-type injectors; water in turbines corrodes turbine lubricant circulatory systems, particularly the governor mechanisms of steam turbines; water in hydrocarbon oils, such as gasoline, rusts steel storage tanks and drums; water in anti-freeze compositions causes corrosion in automobile radiators, etc. Corrosion not only has a deleterious effect upon the metal surfaces, but also frequently loosens finely divided metal oxides which may act as oxidation catalysts increasingthe rate of deterioration of various organic compounds with which theycome in contact or they may enter between moving parts of machinery where they act as abrasives.

It is a purpose of this invention to treat metal or articles of manufacture containing metals in a way so that they become resistant to normalccrrosion. It is a specific purpose to treat in, a simple manner accurately machined metal parts so that they may be handled without developing-corrosion, particularly in' places where fingerprints have been left. Another purpose is to'protect iron or steel equipment exposed to the atmosphere so that its rusting is prevented or'substantlally retarded. Still another purpose is'to protect mechanical equipment from rusting, which equipment stands idle and/or is shipped over long dis-" tances. A further object is to provide slushing oils of improved rust-protective properties particularly adapted to withstand the effects of marine environment. Another purpose is to produce lubricating compositions suitable for internal combustion engines which compositions possess improved anti-corrosive, detergent and/or other beneficial properties due to the presence of the herein described additives. Still other objects will be apparent from the present description.

It has now been found that excellent anticorrosive properties toward metals are possessed by organic acidic compounds (or their corresponding metallic salts) which contain a minimum of about 10-16 carbon atoms so as to be oil-soluble and are characterized by the presence of a sulfonyl radical not more than about three or four atoms removed from the acidic radical, which sulfonyl radical is in turn directly connected to a nuclear carbon-atom of a cyclic radical having aromatic characteristics.

These compounds have the formula ii (i)? wherein R1 is an organic radical which is directly connected to S by an atom of a nucleus having aromatic characteristics; R2 is an organic radical having a minimum of about 10 carbon atoms when n=0, or when n=1 or more this necessary minimum of oil solubilizing carbon atoms may be made up from substituents on alone or in combination with the carbonatoms of R: (thus when has 10 more carbon atoms, R: may be a hydrogen atom); 11, equals zero, one, two or three (preferably zero or one) that isn+1 is an'integer of from 1 to 4; and X is an, acidic radical such as COOH, CSOH, COSH, CSSH SH, SOaH, POaH, etc. or their =metallic equivalents-$00M, CSOM, COSM, CSSM, SM, SO3M, PO3M, etc'., wherein M represents the hydrogen equivalent of a metal. The free bonds of may be attached to hydrogen atoms, inorganic or organic radicals; preferably hydrogen atoms and/or low molecular weight alkyl radicals.

Illustrative examples of R1 are phenyl, tolyl, xylyl, crecyl, cumenyl, cymyl, anisyl, furyl, thienyl, pyrazolyl, pyrryi, pyridyl, oxazyl, thiazyl, quinolyl, isoquinoiyl, salicyl, thymyl, indyl, cumaryl. thianaphthyl, anthryi, carbazyl, acridyl, and the like. It will be seen that these have generally five or six member rings characterized by conjugated double bonds in the ring.

B: may have any of the above values given for R1 providing they contain the necessary number of carbon atoms or Rs may be exemplified by nonaromatic (cyclic or acyclic) radicals such as methyl, ethyl, normal and iso-propyl, n-, iso-. secondary and tertiary butyl, the various pentyl. hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetra decyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl radicals, their analogues, homologues and suitable derivatives.v

For purposes of oxidation stability, particularly at high temperatures, the compounds should be saturated or have no more than about one olefinic or acetylenic bond per molecule. However, for employment under conditions in which stability compounds may be used. The'double bonds of the sulfonyl aromatic or pseudo-aromatic nucleus are not regarded as unsaturated linkages within this meaning. The compounds may also contain substituents which are preferably not too strongly polar such as halogen,

Those compounds in which the acidic group is a carboxyl radical are preferred for rust inhibition. However, the sulfonyl thioric (-COSH or -CSOH) or dithioric (-CSSH) acidsas well as the sulfonyl mercaptans may be preferredin extreme pressure lubricants. Y

The acidic compounds in which the organic sulfonyl group is farther removed than the third or fourth carbon from the acid radical possess decreased or negligible corrosion inhibiting properties although they may be desirable lube oil additives for other reasons.

The free acids are generally more effective corrosion inhibitors than the corresponding metallic salts. However, the salts, particularly the calcium salt, may be preferred for use in compounded lubricating oil due to other improvements contributed to the oil by. the metal such as detergency, anti-ring sticking effect and associated phenomena.

Among the metallic salts of the present acidic sulfonyl compounds. the polyvalent metal salts are preferred, particularly the salts of the alkaline earth metals (Ca, Ba, Sr, Mg). The salts of other polyvalent metals may also be used such as Cu, Zn, Al, Pb, Fe, Ni, Co, Mn, Cr, and Sn. However, employment of the monovalent metal salts such as Na, K, Li, is also contemplated.

A particularly eflective group of compounds of the present invention are the alpha beta aromatic sulfonyl carboxylic acids (and their metallic salts) derived from fatty acids containing a minimum of 12 carbon atoms. They may be requirements are not critical, unsaturated prepared by reacting the alpha or beta halo carboxylate with the alkali salt of a thio aromatic compound and then oxidizing the resulting aromatic thio carboxylate (or its free acid) to the corresponding sulfonyl compound by ways known to the art.

For example, alpha phenyl sulfonyl stearic acid,

H HaCIr-( J-COOH bon solvent its melting point was determined asv -56 C. Equivalent weight: found 392; calculated 392.

The alpha thiophenyl stearic acid was oxidized with an excess of 30% aqueous hydrogen peroxide in acetic acid for 16 hours at 100 C. After recrystallization from a hydrocarbon solvent the melting point of the alpha phenyl sulfonyl stearic acid was determined as 94-955 C. Equivalent weight: found 424; calculated 422.

Instead of using hydrogen peroxide, oxidation of the sulfide to the corresponding sulfone may be eifected with permanganate solution.

The alpha phenyl sulfonyl stearic acid was treated with an equivalent amount of lime to yield its calcium salt. This was a colorless resinlike solid.

Alpha tolyl sulfonyl stearic acid was prepared from alpha brom stearic acid and sodium thiocresylate in the foregoing manner. It had a melting point of 79-84" C. Equivalent weight: found 437; calculated 438.

As illustrative non-limiting examples or car boxylic acids, the.aromatic sulfonyl derivatives of which may be formed according to the present invention, particular mention may be made of lauric, tridecoic, myristic, pentadecoic, palmitic,

' margaric, stearic, nondecoic, arachidic, heneicosoic,.their analogues, homologues, isomers and suitable substituted derivatives. The acids may also contain aliphatic, alicyclic, and/or aromatic substituents. Thus, taking stearic acid as an example, a few of the many suitable substituted stearic acids would be cyclohexyl stearic acid, phenyl stearic acid, naphthenyl stearic acid, etc. Naphthenic acids such as are derived from pctroleum as well as acids obtained by the oxida tion of petroleum or other hydrocarbons may alsobeused.

The invention may be further illustrated by reference to the following modified Kuebler or Westinghouse corrosion tests. Steel strips (3" x x it") were completely immersed in 460 ml. samples of oil which were continuously agitated with electric motor-driven glass stirrers. Thirty minutes after starting, 10% volume of synthetic sea water was added to each sample. The tests were continued for 48 hours at a controlled temperature of 75 C. and the amount of rusting on the strips then noted. (The synthetic sea water was made up from the following formula: in ml. water11.0 3. Mg. Ch'GHsO;

1.2 g. CaC'l: (anhytion 14-0-15 (INT), March 1943 by which test theemulsion should break in 30 minutes to be considered satisfactory.

Results were as follows:

are most useful; for'exarnple. various alkl phenol or naphthoi carboxylic acids wherein the carboxylic acid radical is attached to the nucleus directly or through a carbon linkage, e. g., alkyl salicylic acids. preferably those whose alkyl radicals contain 12 or more carbon atoms.

The addition of these auxiliary acids to hydrocarbon oils containing the primary anti-corrosive's is of greatest importance when dealing with well-refined hydrocarbon compositions. Conventional refining methods, such as acid and alkali treatment, solvent extraction, hydrogenation, etc., remove naphthenicand other monocarboxylicacids-which' may naturally be con- Emulslon test at Cone of Film '1 130 F.

euac- Additive additive Base Oil Rustin! y Tut w/sos w/waier water bPer civil u we a t Minutes Mfnu! Alpha phenyl sulfonyl stearic 0. 015 Calif. turbo raiilnate contain- 0K 48 hrs 30-40 min 25 1 8 acid. EEO per cent w. oxidation ibltor. Do 0. 01 Mid-Continent turbo railinate. do min Alpha tolyl sulionyl stearic 0.015 Calif. turbo rafllnate contain- .do 1hr acid. ing 0.25 cent w. oxidation inhl itor. Calcium salt of alpha phenyl 0. 016 do Slight traces rust 48 hrs snlfonyl stearic acid.- Alpha phenyl sulionyl stearic 0. 0075 do 0K 48 hrs 2 hrs 26 acid plus alkyl succinic acid. 0.0075 Alpliig lauryl sulfonyl stearic 0.01 Mid-Continent turboraflinota Abitllithiio per cent rusted ac a 2'.

Do 0.02 .do Allu'zugs per cent rusted st rs. Alkyl suocinic acid 0.016 Calif. turbo raflinate contain- '2 large spots and several mg 0.25 per cent w. oxidaspecks at 48 hrs.

tlon inhibitor.

1 Approximate molecular weight=400.

The great superiority of the sulfonyl carboxylic acid in which the sulfur is attached to an aromatic radical over a corresponding sulfonyl carboxylic acid in which the sulfur atom is attached to an aliphatic chain may be seen from the foregoing data.

It will be observed also that the present sulfonyl compounds exert a synergistic anti-corrosive effect in combination with other carboxylic corrosion inhibitors. These latter are oil-soluble dicarboxylic acids or hydroxy aromatic carboxylic acids having a minimum of about 16 carbon atoms. It is desirable that their active radicals, i. e., the several carboxylic radicals, or carboxylic and hydroxyl radicals, as the case maybe, he as close to each other as possible and be separated from each other by not more than 4, and preferably by not more than 2, intervening atoms. Stability of the acids under conditions to which the compositions are exposed is an added requirement.

Among the dicarboxylic acids which are particularly useful for preventing-corrosion are various alkylated aliphatic dicarboxylic acids such as suctained in the hydrocarbons in small amounts and which may enhance the action of the anti-corrosives. However, even if small amounts of naphthenic and similar acids are naturally present, in general the addition of further, amounts of the auxiliary acids of the type described is beneficial. Without wishing to be committed to a particular theory of why this combination of sulfone and dicarboxylic acid produces such an effective antirusting combination, it seems that the sulfonyl cinic, glutaric, adipic, etc. acids. If desired, these acids may contain various substitution radicals as hydroxyl, ether," amino, nitro, hydrosulflde, sulfide, halide, etc., radicals, the most important limiting factor being the necessary stability. In general, it is preferred to use a saturated aliphatic dicarboxylic acld'having thecarboxyl radicals as close to each other as possible as is consistent with the requirement for stability. Particularly effective are alkyl succinic acids having at least 16, and preferably 20 to 40 carbon atoms.

Of the hydroxy carboxylic acids, hydroxy aromatic carboxylic acids in which the hydroxy radical is directly attached to the aromatic nucleus compound more rapidly forms a protective film than the dicarboxylic acid so that the sulfone yields better initial (or quicker) protection while the dicarboxylic acid produces enhanced ultimate protection.

The sulfone. in addition to afl'ording rust protection itself, also promotes the formation of a protective film of the dicarboxylic acid on a metallic surface. This combination of sulfone and dicarboxylic acid is particularly important in connection with the rust inhibiting of highly refined lubricatingcompositions such as turbine oil since the refining treatment may reduce the solubility of the oil for either corrosion inhibitor.

In general. amounts of these auxiliary dicar boxylic acids between about 0.001% and 0.1% may be used in petroleum distillate oils; in bright stocks up to about-1% is'indicated, while in plastic compositions higher amounts, even up to 5-10% maybeuseful;

The dispersion of the present anti-rusting compounds may be a true or colloidal solution in a suitable vehicle which is capable of flowing under the conditions of use, i. e., is liquid or plastic at the temperature employed. Both true solutions and colloidal dispersion in various vehicles are eiiective in the matter of corrosion protection. However true solutions are preferred for two reasons: first. colloidal solutions may. under many circumstances. coagulate, in which case the activepmtective agent would be eliminated; and second, colloids tend to cause emulsification of oil vehicles with water, emulsiflcation in many instances being very undesirable as in the lubrication of steam turbines.

to their being able to act as carrier for the acids under normal atmospheric conditions) that they The treating temperature for metals is preferably about room temperature if the vehicle is normally liquid. although lower or higher-temperatures may be employed. The lower tempera-' ture limit is usually determined by the solidification temperature of the liquid, and temperatures should be below'the boiling temperature of the vehicle and below the decomposition temperatures of boththe vehicle and the corrosion inhibiting compounds.

Metals capable of being thus protected are in particular the ferrous metals. e. g.. soft iron, various steels. cast iron, and to a lesser extent copper, brass, bronze, zinc, aluminum, magnesium alloys, various bearing metals as copper-lead, cadmium-nickel, silver-nickel, etc.

Articles containing these metals are toonumerous to recite. However, it may be mentioned that the problem of rust prevention is critical. for example, where accurately machined parts are involved such. as piston rings. engine cylinders, bearing shafts, plungers of pumps. etc. In other instances, rust prevention may perhaps not be critical, but of vast economic importance as, for example, in the mass production of steel castings which are piled up and often set in the open for months before being finished.

Corrosion may be due not only to atmospheric exposure, but may be caused or accelerated by contact with acidic materials. for example, by touching with the fingers. It may also occur in closed systems. as in internal combustion engines, steam turbines, pipelines. etc., due to the-corrosive influence of various impurities such as water, oxygen, carbon dioxide. salts. inorganic or organic acids, etc.

The treatment, according to this invention, for the prevention of corrosion may consist of a single contact of the metal to be protected with the dispersion containing the present compounds, or may comprise repeated contacts effected at intervals, or may consist or a continuous treat- I ment lasting as long as the use of the particular dispersion or piece of equipment or both. The

choice of any particular type of these treatments is usually dictated by circumstances. For example, if newly machined and finished machine parts are to be'rust-proofed, they may be dipped or sprayed with a suitable dispersion, and then stored away. On the other hand, if rust prevention in a steam turbine is desired.it is preferable that the circulating lubricating oil contain the active rust-preventive compound and contact is made as long as this oilia used. Should. after a while, this oil be discarded and be replaced by another one not containing a rust-preventive, the corrosion protection usually lasts for along time thereafter, due to the protective film left behind. In cases where this film is mechanically destroyed, as in hearings or gears. etc.. running under extreme loads. the protective film must be renewed continuously,.otherwise rust protection fails.

The vehicles to which the compounds oi this invention may be added for the p po e of producing corrosion-protective compositions may be divided into several groups. In the first place, they may be liquids or plastics, the only requirementsastotheirphysicalstatebeing (inaddition be spreadable over metal surfaces. SpreadinlI may be accomplished by immersing, flooding, spraying, brushing, trowellins. etc. After bein applied, all or part of the vehicle may evaporate. or it may be more or less permanent. In other words, both volatile carriers may be used. or substances which do not materially volatilize under normal atmospheric conditions. As to chemical requirements, the vehicle must be stable under ordinary conditions of storage and use and be inert to the active inhibitors.

Thus, the vehicle should preferably be substantially neutral, although it may be weakly acidic or basic, preferably having a dissociation constant not above about 10 In vehicles of low dielectric constant, as hydrocarbon oils, which are not conducive to ionization of dissolved electrolytes,

relatively small amounts, 1. e.. about 0.1% to 5% of various carboxylic acids, such as fatty or naphthenic acids. may be present, and in many instances this may be beneficial.

Both polar and non-polar vehicles may be employed. Among the former water; alcohols, such as methyl, ethyl. propyl, isopropyl, butyl, amyl. hexyl, cyclohexyl, heptyl,methyl cyclohexyLoctyl, decyi. lauryl, myristyl, cetyl, stearyl, benzyl, etc.. alcohols; polyhydric alcohols as ethylene glycol, propylene glycol, butylene glycol, glycerol, methyl glycerol, etc.; phenol and various alkyl phenols;

ketones as acetone, methyl ethyl ketone. diethyl ketone,- methyl propyl, methyl butyl, dlpropyl ketones, cyclohexanone and-higher ketones; keto alcohols as benzoin; ethers as diethyl ether, diisopropyl ether, diethyiene dioxide, beta-beta dichloro diethyl ether. dipheny1 oxide, chlorinated diphenyl oxide, diethylene glycol. triethylene glycol, ethylene glycol monomethyl ether, corresponding ethyl. propyl, butyl ethers; neutral estersv of carboxylic and other acids as ethyl. propyl, butyl, amyl. Dhenyl', cresyl and higher acetates. propionates, butyrates, lactates. laurates, myristates, palmitates, stearates, oleates. ricinoleates, phthalates, phosphates, phosphites, thiophosphates, carbonates; natural waxes as carnauba wax, candelilla wax. Japan wax, jojoba oil, sperm oil; fats as tallow, lard' oil, olive oil, cottonseed oil, perilla oil. linseed oil. tung oil. soya bean oil, fiaxseed oil, etc.; weak bases as pyridine. alkyl pyridines, quinolines. petroleum bases, etc.

Vehicles of little or no polarity with which the present compounds may be used comprise hydrocarbons or halogenated hydrocarbons as liquid butanes, pentanes, hexanes, heptanes, octanes, benzene, toluene..xyienes, cumene, tetraline, indene, hydrindene, alkyl naphthalenes; gasoline distillates. kerosene, gas oil. lubricating oils (which may besoap-thickened to form greases) petrolatum, parafiln wax, albino asphalt, carbon tetrachloride, ethylene dichloride, propyl chloride. butyl chloride, chlor-benzol, chlorinated kerosene, chlorinated paramn wax, etc.

The amounts of the present compounds which must be incorporated in the above vehicles to produce corrosion-protective compositions vary considerably with the type. of vehicle used. As a general rule, the presenceof resinous materials,

particularly those of a colloidal nature, calls for 9 resins formed by esteriiication of polyhydricalcohols with polycarboxylic acids, etc.

In the absence of such resinous materials,

. amounts required of the sulfonyl compounds vary from about 0.001% up to about 0.1%, although larger amounts may be used. However, where the rust retarding compounds are in colloidal dispersion, rather than in true solution, a concentration in excess of about 0.1% may result in relatively quick loss oi. part of the inhibitor by precipitation and settling.

In the presence of resins and other colloids, amounts in excess of 0.1% and up to say 5% may be required. Inasmuch as resins may act as protective colloids, compositions containing these larger amounts of colloidally dispersed inhibitors, together with resin, may be quite resistant to precipitation and settling.

when the metallic salts of the organic sulfonyl compounds are employed as detergents in lubricants for internal combustion engines, effective amounts are about 0.25% to about 5% although somewhat higher or lower quantities may be used. Mixtures of several acids or of several salts or mixtures of one or more acids with one or more salts may also be used.

Since resinous and gummy substances in the vehicles do call for greater amounts of inhibitors, it is usually desirable to refine normally liquid vehicles thoroughly and free them from gummy substances, thereby imparting to them maximum inhibitor susceptibility. This is of particular importance, for example, in lubricating oils, specifically steam turbine oils, which are advantageously highly refined before the inhibitor is introduced. 'Suitable refining treatments in-- clude, for example, extraction with selective solvents. for aromatic hydrocarbons such as liquid sulfur dioxide, phenol, furfural, nitrobenzene, aniline, beta-beta-dichloro-diethyl ether, antimony trichloride, etc.; treatment with AlCla, sulfuric acid, clay, etc. If the treatments produce a sludge, special care must be taken to remove it very thoroughly and completely.

When the additives are employed in a lubricating 01! for internal combustion engines (either as anti-corrosives, detergents or for both purposes), other additives may also be present, such as blooming agents, pourpoint depressants or viscosity improvers, anti-oxidants, extreme pressure agents, detergents, anti-foaming agents, etc. Thus, oil-soluble detergents may include the oilsoluble salts of various bases with detergent forming acids. Such bases include metal as well as organic bases. Metal bases includethose of the alkali metals, Cu, Mg, Ca, Sr, Ba. Zn, Cd,Al, Sn, Pb, Cr, Mn, Fe, Ni; .Co, etc. Organic bases include various nitrogen bases as primary, secondary, tertiary and quaternary amines.

Examples of detergent forming acids are the to various fatty acids of say, 10 to 30 carbon atoms,

wool fat acids, parafiin wax acids (produced by oxidation of paraflin wax), chlorinated fatty acids, rosin acids, aromatic carboxylic acids including aromatic fatty acidahromatic hydroxy" fatty acids, paraflfln wax benzoic acids, various alkyl salicyic acids, phthalic acid mono ester, aromatic keto acids, aromatic ether acids; diphenols as di-(alkylphenol) sulfides and disulfldes, methylenebis alkylplienols; sulfonic acids such as may be produced by treatment oi alkyl aromatic hydrocarbons or high boiling petroleum oils with sulfuric acid; sulfuric acid mono esters; phosphoric, arsonic and antimony acid mono and di esters, including the corresponding thio phosphoric, arsonic and antimony acids; phosphonic and arsenic acids: etc.

Other detergents are the alkali earth phosphate d1 esters, including the thiophosphate di esters;

5 the alkali earth diphenolates, specifically the calcium and barium salts of diphenol mono and poly sulfides; etc.

Non-metallic detergents include compounds such as the phosphatides (e. g. lecithin), certain fatty oils as rapeseed oil,'voltolized fatty or mineral oils, etc.

Anti-oxidants comprise several types, for example alkyl phenols such as 2,4,6-trimethyl phenol, pentamethyl phenol, 2,4-dimethyl-6-tertiary butyl phenol, 2,4-dimethyl-6-octyl phenol, 2,6-

ditertiary butyl-4-methyl phenol, 2,4,6-tritertiary butyl phenol, etc.; amino phenols as benzyl amino phenols; amines such as dibutyl phenylene diamine, diphenyl amine, phenyl alpha naphthyl amine, phenyl beta naphthyl amine, dinaphthyl amines; various sulfurized compounds, as sulfurized sperm oil, sulfurized jojoba oil, sulfurized resins or olefin polymers, paraiiln wax polysulfides, sulfurized tall 011, sulfurized terpene hydrocarbons, methylene bis aryl sulfides, etc.

Other corrosion inhibitors may also be present, such as alkali metal and alkali earth salts of sulfonic acids and fatty acids, organic compounds containing a nitrile, nitro, ornitroso group in close proximity 'to an acidic radical (e. g. alpha cyano stearic acid), etc.

The invention claimed is: 1. A composition of matter comprising a major amount of a liquid hydrocarbon containing finely dispersed therein a minor amount, suillcient to inhibit corrosion, of an organic sulfone of the four; the H iii)? portion of the sulfone having a minimum of oil-soluble.

2. A composition of matter comprising a major amount of a liquid hydrocarbon containing finely dispersed therein a minor amount, sufllcient to inhibit corrosion, of an organic sulfone of the formula 1 which is directly connected to S; R: is a radical from the group consisting of an alkyl, aralk'yl,

plus one is an integer of one to four; the

about 10 carbon atoms which render the sulfone wherein R1 is an aryl radical, a nuclear atom of assnev'a portion of the sulfone having \a minimum of about carbon atoms which render the sulione oil-soluble.

3. A composition of matter comprising a major amount of a liquid hydrocarbon containing finely dispersed therein a minor amount, suiiicient to inhibit corrosion, of an organic sulfone of the formula Rr-E-E- x i i.

wherein R1 is an'aryl radical, a nuclear atom of which is directlyconnected to S; R: is a radical from the group consisting of alkyl, aralkyl, and cycloalkyl radical in which the alkyl group is a long chain; X is an alkaline earth metal carboxylate radical; and 12 plus one is an integer of one to four; the

formula wherein R1 is an aryl radical, a nuclear atom of which is directly connected to S; R: is aradical from the group consisting of an alkyl, aralkyl, and cycloalkyl radical in which the alkyl group is a long chain; X is selected from the group consisting of carboxyl and alkaline earth metallic carboxylate radicals; and n plus one is an integer of one to four; the

wherein R1 is.an aryl radical, a-nuclear atom of which is directly connected to S; R: is a radical from the group consisting of an alkyl, aralml, and cycloalkyl radical in which the alkyl group is a long chain; X is a radical from the group consisting of a carboxyl radical and a metal salt thereof; and 11 plus one is an integer of one to four; the

12 portion 'of the sulfone having a minimum of about 10 carbon atoms which render the sulfone oil-soluble.

7. A compounded lubricating composition comprising a major portion of refined mineral oil and a corrosion-inhibiting amount of an alkaline earth salt of an alpha aromatic sufonyl derivative of a carboxylic acid having a minimum of 12 carbon atoms.

8. A compounded lubricating composition comprising a major portion of refined mineral oil and a corrosion-inhibiting amount of an alpha aromatic sulfonyl derivative of a carboxylic acid having a minimum of 12 carbon atoms.

9. Refined lubricating oil containing about 0.001% to 5% ofthe calcium salt of an alpha aromatic sulfonyl carboxylic acid, said carboxylic 7 acid having a minimum of 12 carbon atoms.

, 10. Refined lubricating oil containing about 0.001% to 5% of an alpha aromatic sulfonyl carboxylic acid, said carboxylic acid having a minimum of 12 carbon atoms.

11. Refined lubricating oil containing about 0.001% to 0.1% of an alpha aromatic sulfonyl carboxylic acid in which the carboxylic acid portion contains a minimum of 12 carbon atoms and about 0.001% to 0.1% of an alkyl succinic acid having a minimum of 16 carbon atoms.

12. A composition of matter comprising a major amount of a non-aqueous medium having a dissociation constant below about 10', containing finely dispersed therein a minor amount, suflicient to inhibit corrosion, of an organic sulfone of the formula th H iii)? portion of the sulfone having a minimum of about 10 carbon atoms which render the sulfone oil-soluble. 4

13. A compounded lubricating composition comprising a major amount of mineral oil and a minor amount sufficient to inhibit corrosion,

of alpha phenyl sulfonyl stearic acid,

14. A compounded lubricating composition comprising a major amount of mineral oil and a minor amount, suflicient to inhibit corrosion, of alpha tolyl sulfonyl stearic acid.

15. A compounded lubricating composition comprising a major amount of mineral oil and a minor amount, sufficient to inhibit corrosion, of calcium salt of alpha phenyl sulfonyl stearic acid.

18. A compounded lubricating composition comprising a major amount of mineral oil, a minor amount sufllcient to inhibit corrosion of aryl substituted sulfonyi containing fatty acid having from 10 to 16 carbon atoms, said sulfonyl radical being not more than two carbon atoms removed from the carboxylic acid radical of said fatty acid and a minor amount sumcient to exert a synergistic anti-corrosive effect when in the presence of the sulionyl compound of an organic acid of the group consisting of alkyl dicarboxylic acid and hydroxy aromatic carboxylic acid having a minimum of 16 carbon atoms.

17. A compounded lubricating composition comprising a major amount of mineral oil and a minor amount, suflicient to inhibit corrosion of alpha phenyl sulfonyl stearic acid and from about 0.001% to about 0.1% of an alkyl succinic acid having a minimum of 16 carbon atoms.

18. A compounded lubricating composition comprising a major amount of mineral oil and a minor amount, suflicient to inhibit corrosion of alpha tolyl sulfonyl stearic acid and from about 0.001% to about 0.1% of any alkyl succinic acid having a minimum of 16 carbon atoms.

19. A compounded lubricating composition comprising a major amount of mineral oil and a minor amount, sumcient to inhibit corrosion of calcium salt of alpha phenyl sulfonyl stearic acid and from about 0.001% to about 0.1% of an alkyl succinic acid having a minimum or 16 carbon atoms.

20. A compounded lubricating composition comprising amajor amount of a mineral oil, and a minor amount, sufllcient to inhibit corrosion, of an aryl substituted sulfonyl containing fatty acid having from 10 to 16 carbon atoms, said sulfonyl radical being in the alpha position to the carboxylic acid radical of said fatty acid. 21. A compounded lubricating composition comprising a major amount of a mineral oil, and

a minor amount, suflicient to inhibit corrosion,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,010,754 Felix Aug. 6, 1935 2,125,072 Kern July 26, 1938 2,257,969 Loane Oct. 7, 1941 2,280,419 Wilson Apr. 21, 1942 2,334,158 von Fuchs Nov. 9,- 1943 2,349,044 Jahn May 16, 1944 2,349,817 Farrington May 30, 1944 2,257,750 Lincoln Oct. 7, 1944 2,257,751 I Lincoln Oct. '7, 1944 2,257,752 Lincoln Oct. 7, 1944'