US2360302A - Compounded hydrocarbon oil - Google Patents

Description

Patented Oct. 10, 1944 STATES FATE '5 2,360,302 COMPOUNDED HYDROCARBON OIL of Delaware No Drawing. Application August 2, 1940,

Serial No. 350,056

16 Claims.

This invention relates to a new and useful composition of matter and a method of preparing the sar'ne.- It involves a hydrocarbon oil containing a reaction produce of unknown constitution and of a relatively high molecular weight.

The production of improved hydrocarbon oils, and particularly of lubricating oils having desired characteristics, has been the subject of extensive research and investigation. Generally speaking, the compounding of hydrocarbon oils to obtain desired characteristics involves empirical phenomena, and the action of untested types of compounding agents cannot be predicted.

It has long been the desire of the lubricating oil compounding art to obtain an oil, particularly of petroleum origin, which alone or with the addition of relatively small amounts of compounding agents would resist deterioration or degradation when subjected for long periods of time to high temperatures and pressures in the presence of metals, air or oxygen or hydrocarbon partial combustion products. Deterioration of the character referred to manifests itself in diverse effects, depending upon the nature and degree of refinement f the hydrocarbon oil and upon the environment to which it is subjected. In Diesel engines, the effect is manifested by piston ring sticking. In these engines, the exposure of a lubricating oil to such temperatures as 425 to 650 F. in the presence of oxidizing combustion gases at pressures as high as 750 to 1150 lbs. per square inch causes the deposition of oil degradation products. of such a cementitious character as to eifectively'take piston rings out of service. In automobile engines the deposition of sludge in the crankcase oils and the formation of varnish on the cylinder walls of the engine are observed to be the result of oxidation and/or polymerization phenomena occurring in the degradation process. The corrosion of hard metal bearing surfaces of the type represented by cadmium-silver and copper-lead alloys also is a difiiculty encountered from the deterioration of lubricating oils in internal combustion engines or other services. The adverse effect of deterioration of hydrocarbon oils at elevated temperatures is aggravated by the fact that improvements in the mechanical arts have brought about increasing severity in the conditions to which the oils are subjected.

It has also been the practice in the lubricating 011 art to improve other properties of lubricants by adding ingredients to mineral oil fractions for enhancing the oiliness characteristics, the wear reducing action, the film strength, the color stability, and the viscosity index of lubricating oils.

It is an object of the present invention to improve one or more of the above discussed properties of lubricating oils (i, e., stability against piston ring sticking, varnish" formation, sludging, corrosivity of metal bearing surfaces, oiliness, wear reduction, film strength, color stability, or viscosity index) by incorporating in hydrocarbon oils a compounding agent as hereinafter disclosed.

Metal phenates have been proposed as compounding agents for lubricating oils. Such compounds are efiective in preventing piston ring sticking and gum formation in engines resulting from oxidation and polymerization of the lubricating oil and fuel residues. However, despite the fact that metal phenates have the ability to stabilize hydrocarbon oils, these compounds themselves are relatively unstable to oxidation when subjected to normal engine temperatures in the presence of air. The oxidized metal phenates thus formed during use apparently retain the ability to stabilize lubricating oils against piston ring sticking and gumming but have the disadvantage of being more corrosive to certain bearing metals than the original unoxidized metal phenate. This increased corrosivity of the oxidized product is particularly apparent in oils of the mixed naphtheneparafiin base and of the strictly parafflnic base types.

It has been discovered that metal phenates may be stabilized against oxidation when dissolved in lubricating oils by reacting the phenate with sulfur. The exact chemical constitution of the reaction product is at present unknown to the inventors.

Further, it has been discovered that the reaction product of sulfur and metal phenates coopnates.

erate with mixed naphthene and paramn base as well as paramnic base lubricating oils to yield a compounded lubricant having properties superior to those heretofore obtained.

The lubricating oils of this invention are characterized by the presence therein of the reaction product of sulfur and a metal phenate, preferably a polyvalent metal phenate. Metal phenates which may be utilized in the formation of this reaction product to provide a new composition of matter of the type herein involved comprise the alkali, alkaline earth and other metal pheare sodium phenates, potassium phenates, beryllium phenates, calcium phenates, strontium phenates, barium phenates, magnesium phenates, zinc phenates, cadmium phenates, aluminum phenates, tin phenates and lead phenates.

The phenates to be reacted with sulfur are preferably formed from high molecular weight phenols of the type formula:

(a) Alkyl radicals, such as amyl, isoamyl, hexyl, heptyi, octyl, the isomeric octyls, lauryl, dodecyl (normal or branched chain) tetradecyl and cetyl (normal or branched chain) radicals;'

(b) Aryl, such as the phenyl, diphenyl and naphthyl, radicals;

(c) Aralkyl, such as phenyl-stearyl and similar alkyl radicals connected to the benzene ring of the phenol and having an aryl group as a substituent in the alkyl chain;

(d) Alkaryl, such as benzyl and other radicals where the aryl group is directly attached to the benzene nucleus of the phenol and is substituted with an alkyl group and (e) Cyclic non-benezenoid radicals, such as cyclohexanyl or other alicyclic radicals.

term "thio is intended to include radicals containing divalent sulfur, such as sulfhydryl and thioether groups. Although phenols containing at least one alkyl substituent are preferred, the invention does not preclude compounds containing no alkyl groups. Likewise, the invention embraces metal phenates in which the metal oxide group of the phenate molecule is directly attached to polynuclear aryl groups, such as metal salts of alpha or beta naphthol and of the alkylated naphthols. Also, it is to be understood that the invention is not limited to phenols containing only the foregoing groups but the invention embraces the reaction product with sulfur of phenates containing other substituents such as amino, chloro or other groups.

Specific examples of such metal phenates" Examples of specific compounds which may be reacted with sulfur comprise: sodium diamyl phenate, sodium hexyl phenate, sodium heptyl phenate, sodium octyl phenate, sodium lauryl phenate, sodium cetyl phenate; calcium diamyl phenate, calcium hexyl phenate, calcium, heptyl phenate, calcium octyl phenate, calcium lauryl phenate, calcium cetyl phenate; aluminum diamyl phenate, aluminum hexyl phenate, aluminum heptyl phenate, aluminum octyl phenate, aluminum lauryl phenate, aluminum cetyl phenate; magnesium .diamyl phenate, magnesium hexyl phenate, magnesium heptyl phenate, magnesium octyl phenate, magnesium lauryl phenate,

magnesium-cetyl phenate; chromium diamyl phenate, chromium hexyl phenate, chromium heptyl phenate, chromium octyl phenate, chromium lauryl phenate, chromium cetyl phenate.

As previously stated, polyvalent metal phenates are preferred. Also, the phenolic radical of the polyvalent metal phenate is preferably a monoalkyl parasubstituted phenol.

To guide those skilled in the art in the preparation of the compositions of this invention, the

following specific examples are given:

An alkyl phenol desirable for present purposes may be prepared as follows:

Example 1-.--Phenol and a butene polymer having an apparent molecular weight of 194 and obtained by polymerization of a mixture of butenes containing butene-l, butene-2, and iso-butene were mixed. To this mixture, containing 237 grams of phenol and 500 grams of the above mentioned butene polymers, 140 cubic centimeters of 94% sulfuric acid was added slowly with agitation. The temperature was kept below 65 F. during addition of the acid. The mixture was agitated for two hours after the addition of acid was completed and permitted to come to room temperature. The reaction product was then diluted with an equal volume of water and placed in a sealed autoclave where it was heated at 350 F. for an hour with agitation. The product was washed with water, 5% sodium carbonate solution and again with water in order to free it of sulfuric acid, sulfonates and unreacted phenol. A 93% yield of high molecular weight waterinsoluble alkyl phenol having an acetyl numbe of 181 was obtained.

An additional example of a method of preparing alkyl phenols suitable for use in this invention comprises:

Example 2.-5l1 grams of crude cresylic acid, 900 grams of olefin polymers containing an average of 14 carbon atoms per molecule, and 4'75 grams of 98% sulfuric acid were utilized in preparing an alkylated cresol. These ingredients wer combined and treated in the manner described above for preparation of cetyl phenol.

-The product was vacuum-distilled at 10 mm. and

a 50 to cut of an alkyl phenol obtained which had a molecular weight of 291 and was used to prepare the calcium salt hereinafter described in Example 6.

It is to be understood that the above examples are given by way of illustration only and that other condensation reactions utilizing alcohols, alkyl chlorides and the like rather than oeflns may be adopted as a starting material for introducing the alkyl group into the aromatic nucleus. Also, other known condensation agents, such as aluminum chloride, zinc chloride, etc., may be utilized for effecting alkylation of the phenol. A

mixture of sulfuric and glacial acetic acids mayv be used with advantage as a condensing agent. A suitable mixture comprises 100parts by weight 98% H2804 to 60 parts by weight of glacial acetic acid. The presence of the acetic acid facilitates temperature control and gives a softer, easier handled reaction product.

The following comprise illustrative examples of methods of preparing metal phenates suitable for the reaction with sulfur according to' the pres ent invention:

Example 3. 247 grams of an alkylated phenol having an apparent molecular weight of 247 were agitated for six hours at 500 F. with 64 grams of powdered calcium carbide. A gaseous reaction product containing acetylene was formed and removed. The product remaining in the re-' action zone was a dark-colored brittle solid at room temperature and comprised a calcium salt of the alkylated phenoli 94% of the theoretical yield of calcium alkyl phenate was obtained as shown by an analysis of a sample of the reaction product freed from calcium carbide by filtration of its petroleum ether solution.

Example 4.685 grams of an alkylated phenol having an apparent molecular weight of 290 were agitated for six hours at from approximately 500 F. to 540 F. with 90 grams of calcium carbide. A gas containing acetylene was formed and removed. The product remaining in the reaction zone was a dark-colored brittle solid at room temperature; A yield of calcium alkyl phenate, representing 96% of that theoretically possible, was obtained. 1

Example 5.44 grams of p-cyclohexyl phenol and 20 grams of powdered calcium carbide were heated together at 350 F. for one hour. The product was a tan-colored power insoluble in petroleum ether, soluble in benzene, and comprising the calcium salt of p-cyclohexyl phenol.

Example 6.234 grams of an alkyl cresol (molecular weight 291) and 25 grams of powdered calcium carbide were heated at 530 F. with stirring for four hours. The product obtained comprising the calcium salt of alkyl cresol was a hard brittle solid, soluble in mineral oil.

Example 7.To 217 grams of an alkyl phenol (molecular weight 290) .was added 17.2 grams of sodium metal. The temperature was maintained at approximately 350 F. and the sodium metal added in small pieces while the mixture was stirred mechanically. The evolution of hydrogen was quiet and the time for completion of the reaction was about three hours. At 300 F. the product was a viscous brown liquid. Mineral lubricating oil was added at this temperature to give a 1% solution of the compound.

Example 8.100 grams of an alkyl phenol (molecular weight 290) and 15 grams of aluminum wire were heated together. A crystal of iodine was added as a catalyst. The reaction continued until no further hydrogen evolution was evident. The product was dissolved in petroleum ether, filtered, and the petroleum ether evaporated on a steam bath.

Example 9.500 grams of an alkyl phenol (molecular weight 290) was heated to 520 to 540 F. and a crystal of iodine was added. 30 grams of magnesium turnings were then incorporated in small increments to maintain a rapid but safe evolution of hydrogen. Before the entire quantity of magnesium had been added, the reaction mixture became too viscous to stir even at 600 F. This mixture was dissolved in acid treated Western lubricating oil S. A. E. 30 and topped to 480 F. at 5 mm. pressure in a still.

Example 10.7.6 grams of barium hydroxide were dissolved in 7 cc. of water at 212 F. To this was added, with agitation, about 5 grams of cetyl phenol and 7 cc. of ethyl alcohol to pro-, mote solution of the cetyl phenol and facilitate reaction. The mixture was boiled for about three minutes, extracted with a hydrocarbon thinner, the extract filtered and the thinner evaporated. The product obtained was an amber, brittle semisolid containing approximately 65% 01 the barium salt of cetyl phenol. The reaction product as obtained was dissolved as a 1% solution in lubricating oil and found by engine test to satisfactorily inhibit piston ring sticking.

Metal phenates such as those described in the foregoing examples may be stabilized according to this invention by reacting with a small amount of sulfur, that is, about 1 6 to 1 /2 gram atoms of sulfur per mol of phenate. Preferably, the weight of sulfur is equivalent to about to 1 gram atom per mol. of the phenate. At present A of one gram atom of sulfur per mol of the calcium alkyl phenate appears to yield the optimum reaction product. The reaction of the sulfur and. metal phenate is preferably carried out in an organic solution. For example, the metal phenate may be dissolved in a small amount of a hydrocarbon oil to form a concentrated solution of 50% by weight or more of the phenate in the oil. The preferred proportion of sulfur is then added to this solution, the reacting ingredients stirred and heated at 300 to 320 F. for about one hour. During this period the sulfur reacts with the phenate to a great extent, as shown by immersing clean copper strips in the reaction mixture. At the start of the process these strips become very black and copper sulfide flakes off after five minutes immersion of the strips at 900 F. After the reaction has progressed for an hour the copper strips will show only a reddish-purple color under similar conditions, thus indicating more or less complete reaction of the sulfur with the phenate.

At the end of one hour's heating as above described. the reaction mixture is blown with air and the batch is tested with copper strips at intervals of fifteen to thirty minutes. During this period the copper strips assume a lighter and lighter color, finally going through the test without any discoloration. At this point the airblowing should be discontinued or the batch will darken due to oxidation of the mineral oil solvent.

The following table gives a balance sheet for a typical preparation of the compound of this invention:

Ratio sulfur/calcium, 0.74 Final 1product:

Y eld Calcium, 2.86%

Sulfur, 1.93%

Loss by evaporation 8 Totals Ratio sulfur/calcium, 0.68

Perc ntage lost:

Volatile matter (oil, H 8,

(etylphenoD .L Sulfur (as HgS) Although it is preferred to carry out the above described reaction in a mineral oil solvent, the invention does not preclude stabilization of the metal phenate by direct addition of sulfur to the metal phenate and heating to produce reaction between the molten ingredients in the absence of a solvent. Likewise, the invention does not preclude sulfurization of the substituted phenols prior to conversion thereof to a metal phenate. For example, cetyl phenol may be sulfurized and then reacted with calcium carbide. However. this method is less desirable than that previously disclosed.

The use of catalysts, such as potassium carbonate, sodium carbonate or iodine, in the sulfurization reaction is not precluded.

The reaction product of sulfur and metal phenates should, according to this invention, preferably not substantially color a copper strip when immersed in a mineral oil solution of the reaction product for five minutes at 300 F. This test indicates that substantially all the sulfur is in stable chemical combination with the metal phenate.

The proportion of the reaction product of this invention which is added to mineral lubricating oils may vary widely depending upon the uses involved and the properties desired. As little as 0.1% by weight thereof gives measureable improvements, although from approximately 0.25% to approximately 2% is preferred where the compounded oil is to be used as a crankcase lubricant for internal combustion engines. As much as 50% by weight of the reaction product may be dissolved in mineral oil for. the purpose of preparing a concentrate capable of dilution with lubricating oils and the like. Such concentrates comprise a convenient method of handling the reaction product and maybe used as a compounding agent for lubricants in general as well as for other purposes.

This invention also involves the discovery that salts of substituted acids of phosphorus and the phenate-sulfur reaction products hereinbefore disclosed cooperate to give new results in hydrocarbon oil compositions. Hydrocarbon oils containing this combination of ingredients have greater stability under various operating conditions than do oils containing either one of these types of ingredients alone. The mechanism of this cooperation has not been established and the inventors, therefore, refrain from any attempted explanation of the phenomena observed.

Although the broader aspects of the invention are not so limited it is preferred to utilize, in combination with the phenate-sulfur reaction product, polyvalent metal salts of substituted acids of phosphorus and, still more specifically, alkaline earth metal salts like calcium salts of said acts, in hydrocarbon lubricating oils.

Salts of substituted acids of phosphorus which may be added to hydrocarbon oils such as mineral lubricating oils to provide the second component of the new composition claimed herein comprise metal salts of substituted oxy acids of phosphorus and preferably salts of heavy metals selected from groups II, III, IV and VI of Mendeleeif's Periodic Table of the Elements. Specific examples of such metals are aluminum, calcium, barium, strontium, chromium, and magnesium. Salts of iron, cobalt, nickel, tin, zinc, and lead comprise additional examples of compounds falling within the broader aspects of the invention. The above metals are designated herein as heavy metals" to distinguish from the alkali metals which are not, however,

excluded from the broader aspects of the invention. It is to be understood, however, that the term heavy metals as used herein includes the alkaline earth metals. Ammonium salts of substituted acids of phosphorus are not precluded from the broader scope of the invention and may be utilized as a second component of the composition.

The salts of the substituted acids of phosphorus involved herein are preferably formed from substituted oxy acids of pentavalent phosphorus of the following type formulae:

where R and B may be alkyl, aryl, alkaryl, aralkyl, or cyclic non-benzenoid radicals. Substituted phosphoric acids containing at least twelve carbon atoms are preferred, but where the salts are sufilciently soluble in oil acids containing fewer carbon atoms may be utilized. Examples of preferred type acids are alkyl or alkaryl substituted phosphoric acids having at least twelve carbon atoms in the molecule. However, it is to be understood that the broader aspects of the invention include other types of substituted oxy acids of phosphorus containing more than twelve carbon atoms. Additional examples of substituted oxy acids of phosphorus which may be used in forming the metal salts of the present invention are as follows:

Phosphonic acid Monoester of phosphonic acid Phosphonic acid In all of the above formulae R and B may be alkyl, aryl, alkaryl, aralkyl, or cyclic non-benzenoid groups, which in turn may be pure hydrocarbon constituentfoi' oxygenated hydrocarbons, such as alcohols, ketones, esters, and ethers, or hydrocarbons containing substituted constituents such as halogens, (chlorine, bromine, iodine) amino, or nitro-substituents. Likewise, It may be an oil-soluble heterocyclic constituent, e. g., a nitrogen ring containing a radical.

In general, heavy metal salts of substituted derivatives of oxy acids of phosphorus such as phosphorous acid, HaPOa; hydrophosphoric acid, HzPOa; 'orthophosphoric acid, HaPO4; p rophosphoric acid, H4P2Or, as well as substituted derivatives of thecorresponding thioacids of phos-.

rivatives of acids of phosphorus whenever used herein, it is intended to designate acids containing an organic group of the type previously listed, 1. e., alkyl, aryl, alkaryl, aralkyl, or cyclic nonbenzenoid groups. The organic groups may be either directly attached to the phosphorus atom of the compound or attached thereto through an intervening atom such as oxygen. The term oxy acids of phosphorusLLis intended to designate throughout the specification and claims acids of phosphorus in which only an oxygen atom may intervene between the hydrogen and phosphorus atoms. The term thioacids of phosphorus designates acids in which at least one sulfur atom intervenes between a hydrogen and phosphorus atom.

The preferred acids are substituted orthophosphoric acids and the preferred salts comprise the aluminum, calcium, barium and chromium salts of these acids. Examples of such salts are aluminum lauryl phosphate, aluminum cetyl phosphate, aluminum octadecyl phosphate, aluminum spermol phosphate, aluminum oleyl phosphate, aluminum spermenyl phosphate, aluminum (cetyl phenyl) phosphate, aluminum di-(amylphenyl) phosphate, aluminum naphthenyl phosphate, calcium lauryl phosphate, calcium cetyl phosphate, calcium octadecyl phosphate, calcium "spermo1 phosphate, calcium oleyl phosphate, calcium spermenyl phosphate, calcium (cetyl phenyl) phosphate, calcium di-(amylphenyl) phosphate, calcium naphthenyl phosphate, chromium lauryl phosphate, chromium cetyl phosphate, chromium octadecyl phosphate, chromium spermol phosphate, chromium oleyl phosphate, chromium spermerrvl phosphate, chromium (cetyl phenyl) phosphate, chromium di-(amyl,

calcium di-(3-methyl, 4-ch1oro phenyl) phosphate, chromium di-cyclohexanyl phosphate, chromium di-stearo-glyceryl phosphate, chromium tetra-chloro-octadecyl phosphate, chromium di-(6-chloro, 2-phenyl phenyl) phosphate, chromium di-(3-methyl, -chloro phenyl) phosphate, magnesium di-cyclohexanyl phosphate, magnesium di-stearo-glyceryl phosphate, magnesium tetra-chloro-octadecyl phosphate, magnesium di-(G-chloro, Z-phenyl phenyl) phosphate, magnesium di- (B-methyl, 4-chloro phenyl) phosphate, magnesium lauryl phosphate, magnesium cetyl phosphate, magnesium octadecyl phosphate, magnesium spermol phosphate, magnesium oleyl phosphate, magnesium spermenyl phosphate, magnesium cetyl phenyl' phosphate, magnesium di-(amylphenyl) phosphate, magnesium naphthenyl phosphate, barium di-cyclohexanyl phosphate, barium dr -stearo-glyceryl phosphate, barium tetra-chloro-octadecyl phosphate, barium di-(G-chloro, 2-phenyl phenyl) phosphate, and barium di-(3-methyl,- 4- chloro phenyl) phosphate.

The substituted oxy acids of phosphorus utilized in the present invention may be prepared by methods known in the art. For example, a mixture of a higher alcohol and phosphorus pentoxide iri ethyl ether may be refluxed for several hours. The reaction by which the substituted phosphoric acid is formed in this operation is believed to be represented by the following equa-' where R is an alkyl radical. The alkyl ethyl phosphoric acid is soluble in ether, while the ethyl metaphosphate is not and the ether solution of the former may be separated from the latter by decantation. In preparing the metal salts herein involved, the ethyl group in the ethyl phosphoric acid above mentioned may be hydrolyzed oil? to form the metal salt of the mono-alkyl-ortho-phosphoric acid, i. e., the salt of RHzPO4. This type of operation is not limited to the alkyl derivatives but includes aryl-ethyl-phosphoric acid, alkaryl-ethyl-phosphoric acid, aralkyl-ethyl-phosphoric acid and ethyl phosphoric acids containing a cyclic non-benzenoid group.

The metal salts of the various substituted oxy acids of phosphorus .may be conveniently prepared by reacting the acid with sodium hydroxide or potassium hydroxide and then precipitating the desired metal salt from the solution of the sodium or potassium salt by the addition of the appropriate metal ion. The salt may also be prepared by the direct neutralization of the acid, as, for example, with lime where the calcium salt is to be obtained.

A lubricating oil containing a, metal phenatesulfur reaction product such as previously disclosed and a polyvalent metal salt of a substituted acid of phosphorus is more eflicient in maintaining piston cleanliness and inhibiting piston ring sticking than is an oil containing either of the components alone. For example, oils containing the metal phenate-sulfur reaction product alone may permit, to some extent, the formation of gum on the lower portions'of pistons of Diesel engines. The same oil containing a metal salt of a substituted acid of phosphorus, such as an alkaline earth metal cetyl phosphate, permits slight thermal decomposition of the lubricating oil and some deposition of carbon in the top piston ring grooves of Diesel engines under severe conditions of operation. By using these two ingredients in combination in the lubricating oil, each of which has a disadvantage, an oil having neither of the above described objections is obtained and both formation of gum on the piston skirt and deposition of carbon in the piston ring grooves are prevented or inhibited. There is also a general improvement in the appearance of"engine parts and in the freedom from corrosivity of oils containing this combination of ingredients.

It has also been observed that oils containing a metal salt of a substituted acid of phosphorus, such as calcium cetyl phosphate, form a black deposit when contacted with metal surfaces heated at 425 F. or above. The presence of the reaction product of sulfur and metal phenates in an oil containing such metal salts of acids of phosphorus inhibits such deposits. An additional new result obtained by the combination of inhibitors utilized in this invention comprises increased stability of ie oil solution. Lubricating oils containing metal phosphates alone may become cloudy in storage, and the metal salts of substituted acids of phosphorus tend to precipitate from the oil solution in the presence of moisture. When the reaction product of metal phenates and sulfur is present in the lubricating oil the solution of-the metal salts of acids of phosphorus becomes more stable in the presence of water and precipitation or cloud formation is inhibited.

The proportion of metal salts of substituted acids of phosphorus which may be added to mineral lubricating oils according to the principles of the present invention may vary widely. As little as 0.05% by weight of these metal salts gives measurable improvements, particularly as respects the color stability of the compounded oil. From approximately 0.25% to 2% of the phosphate salts may be added to lubricating oils where stability at high temperatures comprises the principal property desired. Concentrates containing high percentages of the phenate-sulfur reaction product and metal salts of substituted acids of phosphorus comprise a convenient method of handling these ingredients and may be used in addition agents for lubricants in general as well as for other purposes.

There is also a preferred range of ratios between the amount of metal salts of substituted acids of phosphorus and the amount of metal phenate-sulfur reaction product in the compounded oil where stability at high temperatures and ability to improve operation of internal combustion engines are the properties to be obtained. This range of ratios may vary from approximately two parts'of the phenate-suifur reaction product to one part of the metal salts of substituted acids of phosphorus, on the one hand, to approximately five parts of the phenate-sulfur product to four parts of the metal salts, on the other hand. This preferred ratio of compounding ingredients is based on the relative amounts of the two addition agents irrespective of the total amount which may be in the oil or of other addition agents which may be present.

In general, it may be said that highly paraflinic or highly refined hydrocarbon lubricating oils respond to stabilization with the metal phenatesulfur reaction products in a manner inferior I to less highly refined lubricating oils, or naphthenic or mixed base oils. By parafllnic lubricating oils" it is intended to designate oils obtained from Pennsylvania crudes and other paraflinic crudes or synthetically prepared parafilnic type oils which are characterized by a viscosity index superior to that of the naphthenic base type oils. The term highly refined lubricating oils" is intended to designate oils which have been subjected to a high degree of refinement with, for example, selective solvents or sulfuric acid in a manner well known in the art. These paramnic or highly refined hydrocarbon lubricating oils demand a premium and have many advantageous properties. They do have disadvantages, among which are inferior response to stabilization with compounding agents and corrosivity to various new bearing metals. 7

Among the above mentioned new bearing materials are binary and ternaryalloys of cadmium and copper; for example, cadmium-silver-copper, cadmium-nickel-copper, and copper-lead-nickel are in use. Compounding agents which may stabilize paraillnic oils against gum formation andthe formation of adhesive deposits have, in

general, not satisfactorily prevented the corrosive action of highly refined or paraflinic oils on these bearing metals in the presence of the compounding agents.

It has been discovered that incorporation of a sensitizer of the thioether type, such as a dialkyl thioether, in hydrocarbon oils improves the responsiveness of the oil to stabilization with either metal phenate-sulfur reaction products or both metal phenate-sulfur reaction products and. salts of substituted acids of phosphorus. Thioethers may be utilized to sensitize or improve the responsiveness of highly refined or parafiinic oils to stabilization with these addition agents. However, the invention is not limited to the improvement of these particular base stocks. The thioethers may likewise be incorporated in oils of moderate or little refinement or in mixed base oils such as Mid-Continent lubricating oils or naphthenic base oils such as Western oils to enhance responsiveness of these oils to stabilization with the foregoing compounding agents.

Examples of sensitizers operative for the purpose of the invention are high molecular weight dialkyl thioethers containing at least one long carbon chain. By long carbon chain is meant a radical containing at least approximately eight The above compounds are represented by the type formula:

R-S--R1 where R and R1 maybe the same or diil'erent alkyl radicals. R and R1 may be either a straight hydrocarbon chain or a branched chain such as obtained from isobutyiene polymers or interpolymers of butylene with isobutyiene and other analogous olefin polymer derivatives.

The proportion of thioether present in the compounded oil may vary from as little as 0.05% which gives measurable improvement to from approximately 0.25% to 2% which is the preferred range. Concentrates containing 5% or more by weight of the thioether, together with corresponding large proportions of the metal phenatesulfur reaction product and the metal salts of on copper-lead bearing metals, and in stabilizing the oil against oxidation, the following data are given:

Lawson engine test results [375 F.1ackot temp, 220 F. oil tcmp., hours duratioul Piston Grfmp Oil discoloru- Remarks No on clogging Per cent Western (naphthonic base) oil S. A. E. (-10 10 Group No. 1 not in same 1 Dltto+.75% calcium cetyl phonate 100 test series.

l)itto+.75 0 calcium cetyl phenom-sulfur re 70 0 Puraillnic use oil (S. A. E. 30) 610 10 Group No. 2 not in same 2 175 95 test series.

0 Ditto S. A. E. 20+.08% calcium cctyl phosphato+.l7% calcium 340 0 cotyl phauato. Ditto S. A. E. 20+.08% calcium cetyl phosphato+.l7% calcium 170 0 3 cetyl phonatc-sullur reaction product. Ditto S. A. E. i0+.08% calcium cotyl phosphate+.l7% calcium 310 0 cetyl phcuatc. Ditto S. A. E. l0+.08% calcium cetyl phosphate+.l7% calcium 235 0 cetyi phcnatc-sulfur reaction product.

Piston discoloration numbers 1 hours hours Parafi'mic base oil S. A. E. +.08% calcium cetyl phosphate+ 180 200 4 .17% calcium cetyl phenatc.

Paratiinic base oil S. A. E. 120+.0871 calcium cctyl phosphate-l- 270 .17917 calcium cetyl pheuate-suliur reaction product.

A measure of piston gumming-the higher the number the greater the amount of gum deposited. 1 300 F. oil temperatures.

Strzp corroszon test results-Copper-lead Weight loss, mg. Weight loss, mg. Increase in vis. Nout. Naph.

at o insol. 24 hrs. 48 hrs. 24 hrs. 48 hrs. 72 hrs. 210 F.

Blended naphthenic-parafliuic base Ditto B. A. E. 10+.25% calcium cctyl phosphate+.5% calcium cetyl phonato... 1. 5 27.0 8 0 9.2 8 8 2 3 1.51 1.62 Ditto S. A. E. 10+.25% calcium cotyl phosphate+.5% calcium cctyl phenatcsulfur reaction product 1.1 7.1 6.8 5.6 7. 4 2. 58 126 Ditto S. A. E. 20+.25% calcium cetyl phosphate+.5% calcium cetyl phenate. 0.3 8.9 16. 3 19.2 20.7 5. 7 1.08 166 Ditto S. A. 20+.25% calcium cetyl phosphate+.5% calcium cetyl phenatesulfur reaction product. 0.3 0.9 3.8 3. 9 8. 1 6. 8 l. 74 94 Ditto S. A. E. 30 0.0 0.0 0.9 4.1 9.2 32.9 0.91 336 Ditto S A. E. 30+.25 um cctyl phosphate+.5% calcium cetyl phcnate. 0.7 2. 5 1 12.1 12. 7 7 11.8 0.98 Ditto S. A. E. 30+.25% calcium cctyl phosphate+.5% calcium cetyl phanatesulfur reaction roduct 0. 3 0. 6 3 2. 7 2. 9 2. 4 7. 7 1.63 111 Paraflimc base 01 S. A. E. 30 0.2 0.4 4 1. 5 8. 3 42.8 6. 9 1.80 96 Ditto+.25% calcium cetyl phosphate+.5%

calcium cetyl phenate 1.3 17.7 2 44.7 111.1 177.8 8 6 0.94 3 Ditto+.25% calcium cctyl phosphate+.5% calcium cetyl pbenate-sulfur reaction product 0.6 3 13 6 35.6 49 2 8 1 1.15 50 Ditto+1% cetyl ethyl thiocthcr+.25% calcium cetyl phosphate+.5% calcium cetyl phenate 1.0 6. 5 11.3 16.6 7.9 1.50 42 Dittoj-1% cetyl ethyl thioether-i-.25% calcium cetyl pbosphate+.5% calcium cetyl pheuate-sulfur reaction product... 0.0 0.3 3. 9 4. 9 6.8 A 2.17 64 300 F. strip corrosion test results Oil Copper-lead corrosion, mgs.

Incr. in viscosity 72 hours 100 F. 210 F.

Neut. Naphtha N o. insolubles Tears V Diesel enuine data Copper-lead connecting a rod bearing weight loss, mg.

RD-4 Caterpillar engine-260 hour:

Blended naphthenic-paraflinic base 8. A. E. 30+

35% calcium cetyl phospbate+.5% calcium cetyl 10 heriate B ended naphthenic-paraflinic base S. A. E. 30+

35% calcium oetyl\pho9phate+.5% calcium cetyl phanate-suliur reactiomproduct 48 Gm. Melon Diesel engines-100 hours Blended naphthenic-paraflinic base 8. A. E. 30+

31.3% calcium cetyl pbosphate+.5% calcium cetyl 740 enate Bi nded naphthenic-parafilnic base 8. A. E. 30+ 1 35% calcium cetyl phosphate-i-.i5% calcium oetyl phenate'suliur reaction product s65 Parafllnic base oil 8. A. E. 30+1% cet l ethyl thloetber+.25% calcium eetyi phosphate .6% calcium cetyl phenate l. 240 Paraflinic base oil 8. A. E. 30+l% cetyl ethyl thicether-+% calcium cetyl hosphate+.5% calcium cetyi phenatesulfur react on product 08 In the Lau son test results of Table II, a single cylinder 2%" bore, 2 /2" stroke, Lauson gasoline engine was operated under extremely severe conditions for the purpose of developing fully piston ring sticking and piston gumming tendencies under circumstances simulating severe operating conditions encountered in the field. Operation of the motor during tests was continuous at 1600 R. P. M. except for periodic shutdowns at fifteen-hour intervals for inspection; the jacket temperature was maintained at 375 F.

and sump oil temperature at 220 F. (except as otherwise noted).

In the corrosion tests whose results are summarized in Tables II and IV thin sheets of copper-lead were cut into strips 1; x 1 /4" x and these strips were immersed in the exemplified oils carried in 2" x 20 glass test tubes; these test tubes were carried in an oil bath maintained at 300 F. (or 325 F. where indicated) :1" F. Each test tube contained approximately 300 cc. of oil, and air was bubbled through each tube at the rate of 10 liters per hour. At the end of each of three 24-hour periods, the strips were removed from the oils, washed with petroleum ether and carefully wiped with a soft cotton cloth; weight losses of the strips were measured in connection with the weight of each individual strip. The duration of the tests was '12 hours.

The corrosion data given in Table V were determined by measuring the loss of weight of metal from bearings during runs with the type of engine indicated under severe operating con-;

ditions a follows: The RD-4 Caterpillar engine was run at 1400 R. P. M., a load of 32 horsepower, with a crankcase oil temperature maintained at 210 F., and oil drains at 60-hour intervals. The General Motors Diesel engine was run at 2000 R. P. M., a load of 110 horsepower, a crankcase oil temperature of 235 F. and no oil drains for the entire period of the test.

The concentrates previously referred to may be prepared and distributed as a hydrocarbon oil or other organic solution containing relatively large proportions of the additive agents. The solvent may be hydrocarbon oils of the lubricating or less viscous type or, if more suitable, an admixture with oil of certain other agents, such as aromatic hydrocarbons, alcohols, esters, ketones or ethers, which are generally of low oils, transformer oils and the like.

molecular weight and of the aliphatic series. These latter blending agents may serve to improve the solubility relationships or thelike of the compounds. agents and lubricating oils or other solvents or carriers containing 50% or more of the essential agents by weight may be thus prepared and distributed for later blendingwith the particular lubricating oilmedia to be put to use as occasion demands. In the preparation of either the finished oils of the invention or of the bases or concentrates referred to, complete or clear and homogeneous solution is not always necessary. Stabilizing or blending agents may be employed to prevent sedimentation of the more oil-insoluble addition agents. The possible detrimental eifect of the presence of filter-able insoluble materials of this character, if they be present, is determined largely by the particular conditions attending the contemplated use and their presence is not in all cases deleterious to the functioning of the composition in its intended manner.

Thecompounded lubricant herein disclosed may have one or more advantages depending upon the particular compounds selected, the proportions utilized, and the environment which the lubricating oil is to encounter. It should be observed, for example, that even though a compounded oil may not be entirely non-corrosive to copper-lead or cadmium-silver alloys, other bearing metals may be little if at all affected by'such corrosive action. Hence, compounding agents or combinations thereof which may not be particularly desirable for one service, where corrosion at high temperatures becomes a factor of importance, may nevertheless be highly useful and extremely advantageous in other services. Likewise, a compounding agent which may not be suflicientlypowerful to adequately stabilizea particular oil stock against deterioration under the most severe conditions may be highly advantageous in such an oil where the environment to be encountered is not so severe, as for example in turbine oils, cable oils, electric'switch Further, the same compounding agent may cooperate with other agents, as disclosed hereinbefore, to adequately stabilize the oil even for the most severe service. The present invention in its broader aspects is therefore not limited to the particular compounding ingredients having the greatest stability or having all of the advantages of the preferred agents or combinations of agents. The invention embraces various of the less advantageous compounding agents or combinations thereof which may find utility in particular applications where all possible improvements in properties of the oil may not be required or where the standard of performance may not be so high.

The compounding ingredients of this invention are not limited in their applicability to any particular base oil stock. The advantages herein disclosed may be obtained with various oil stocks, the selection of which will be determined by conditions and services which the compounded lubricant iS to encounter. The compounding ingredients are useful not only in Pennsylvania oils or Admixtures of the addition The compounding ingredients of this invention may be utilized in hydrocarbon oils containing other compounding agents, such as pour .point depressants, extreme pressure addition agents, blooming agents and the like. Also, the compounds are useful in stabilizing greases, such as greases comprising sodium soaps in mineral oil.

While the character of the invention has been described in detail and numerous examples given, this has been done by way of illustration only and with the intention that no limitation should be imposed upon the invention thereby. Numerous modifications and variations of the illustrative examples may be eilfected in the practice of the invention which is of the scope of the claims appended hereto.

We claim:

1. A compounded lubricant comprising a hydrocarbon oil and a product of the reaction of a polyvalent metal phenate with from approximately to 1 gram atoms of sulfur per mol of said phenate in an amount sumcient to inhibit deterioration of the hydrocarbon oil.

2. A compounded lubricant comprising a hydrocarbon oil, a sulfurized metal phenate in an amount sufllcient to inhibit deterioration of the hydrocarbon oil, and a salt of an acid of phosphorus containing an organic substituent, said salt being present in an amount sufiicient to augment the action of said sulfurized metal phenate.

3. A compounded lubricant comprising a hydrocarbon oil, a sulfurized metal phenate in an amount sufflcient to inhibit deterioration of the hydrocarbon oil. a salt of an acid of phosphorus containing an organic substituent, and a dialkyl thioether, said salt and said thioether being each present in amounts suiliclent to augment the action of said sulfurized metal phenate.

4. A composition of matter comprising a hydrocarbon oil and a sulfurized metal phenate, in an amount sumcient to inhibit deterioration of the hydrocarbon oil.

5. A composition of matter comprising a hydrocarbon oil and a sulfurized polyvalent metal phenate, in an amount sufiicient to inhibit deterioration of the hydrocarbon oil.

6. A composition of matter comprising a hydrocarbon oil and a sulfurized alkaline earth metal phenate, in an amount sufficient to inhibit deterioration of the hydrocarbon oil.

7. A composition of matter comprising hydrocarbon oil and a sulfurized calcium phenate, in an amount sufllcient to inhibit deterioration of the hydrocarbon oil.

8. A composition of matter comprising a hydrocarbon oil and a sulfurized aluminum phenate, in an amount sufllcient to inhibit deterioration of the hydrocarbon oil.

9. A composition of matter comprising a hydrocarbon oil and a sulfurized chromium phenate, in an amount suflicient to inhibit deterioration of the hydrocarbon oil.

10. A compounded lubricant comprising a hydrocarbon oil and a small amount of a stabilized metal phenate in an amount sufficient to inhibit deterioration of the hydrocarbon oil, said stabilized metal phenate being the reaction product of sulfur and a metal salt of a phenol of the type formulain which u, v, w, a: and y are selected from the group consisting of hydrogen, oxy, hydroxy, thio, and oil-solubilizing radicals.

11. A compounded lubricant comprising a hydrocarbon oil and a small amount of a stabilized metal phenate in an amount sufilcient to inhibit deterioration of the hydrocarbon oil, said metal phenate being stabilized by reaction with sulfur.

12. A composition as in claim '7, in which the sulfurized calcium phenate is a product of the reaction of a calcium phenate with about gram atom of sulfur per mol of phenate.

13. A composition as in claim 2, in which the ratio of said phenate to said salt is between about 2 to 1 and about 5 to 4.

14. An addition agent capable of inhibiting the deterioration of hydrocarbon lubricating oils which comprises a concentrated solution in a hydrocarobn oil of a sulfurized polyvalent metal phenate having an oil-solubilizing oganic substituent and a polyvalent metal salt of an acid of phosphorus having an oil-solubilizing organic substituent, said concentrated solution containing more than 2% by weight based on the oil of the said sulfurized metal phenate and more than 2% by weight based on the oil of the said rpolyvalent metal salt, said solution being capable of dilution with hydrocarbon lubricating oil to form a homogeneous mixture containing from approximately 0.1% to 2% by weight of the sulfurized metal phenate and from approximately 0.05% to 2% by weight of the polyvalent metal salt.

15. An addition agent capable of inhibiting the deterioration of hydrocarbon lubricating oils which comprises a concentrated solution in a hydrocarbon oil of a sulfurized polyvalent metal phenate having an oil-solubilizing organic substituent and a polyvalent metal salt of a acid of phosphorus having an oil-solubilizing organic substituent and a high molecular weight dialkyl thioether, said concentrated solution containing more than 2% by weight based on .the oil of the said sulfurized metal phenate and more than 2% by weight based on the oil of the said polyvalent metal salt and more than 5% by weight based on the oil of the said thioether, said solution being capable of dilution with hydrocarbon lubricating oil to form a homogeneous mixture containing from approximately 0.1% to 2% by weight of the sulfurized metal phenate and from approximately 0.05% to 2% by weight of the polyvalent metal salt and from approximately 0.05% to 2% by weight of the thioether.

16. A compounded lubricating oil comprising a hydrocarbon 011 containing, by weight based on the hydrocarbon oil, between 0.1% and 2% of a sulfurized ipolyvalent metal phenate having an oil-solubilizing organic substituent, between 0.05% and 2% of a polyvalent metal salt of an acid of phosphorus having an oil-solubilizing substituent, and between 0.05% and 2% of a high molecular weight dialkyl thioether.

DORR H. ETZLER. BRUCE B. FARRINGTON.