US2480664A - Lubricating oil composition - Google Patents

Description

Patented Aug. 30, 1949 2,480,664 LUBRICATING OIL COMPOSITION John G. McNab, Cranford, and George M. Mc- Nulty and 'lhomas Cross, Jr., Union,'N. J., as-

signors'to Standard Oil Development Company, a corporation of Delaware t No Drawing. Application September 6, 1946,

Serial No. 695,288

Claims. (Cl. 25242.7)

The present invention relates to an additive which imparts detergent properties to mineral lubricating oils.

It is well known that the alkaline earth metal saltsof alkylated phenol sulfides are effective as detergents and sludge dispersers for lubricating oils which are employed as crankcase lubricants for internal combustion engines. The preparation of calcium salts of this type and their use in lubricating oils are described in the Mikeska U. S. Patent 2,362,289. Similarly, barium salts are described in the Winning U. S. Patent 2,362,291, and the magnesium salts are described in the McNab U. S. Patent 2,362,292. Now we have discovered that mixed alkaline earth salts of alkylated phenol sulfides containing two alkaline earth metals are distinctly and surprisingly superior to the single salts in their detergent effects. For example, a mixed calcium and barium salt of tertiary octyl phenol sulfide in which the barium content is only about of the total metal content on a molecular weight basis gives a much cleaner engine condition than a similar concentration of either the calcium salt or the barium salt.

In accordance with the present invention, mixed alkaline earth metal salts of alkylated phenol sulfides having at least one alkyl group of at least four carbon atoms attached to each benzene nucleus and containing two alkaline earth metals are employed as additives for mineral lubricating oils. For the purpose of this invention, the alkaline earth metal group includes calcium, barium, strontium, and magnesium. The presence of alkyl groups in the salts is necessary to impart sufilcient oil solubility. The alkyl groups should contain at least four carbon atoms each and preferably contain from four to eight carbon atoms. The radicals may be straight chain or branched.

he scope of the invention is not limited as to the 11 her of sulfur atoms which interconnect the b nzene nuclei, but compounds containing from 0%: to four sulfur atoms in such linkage are p ferred.

Methods of preparing alkylated phenol sulfides are well known and are described, for example, in the above-cited United States patents. The

mixed metal salts of the present invention may be prepared by neutralizing a phenol sulfide with a mixture of basic compounds of the alkaline earth metals, e. g., the hydroxides; or they may be prepared by first partially neutralizing the phenol sulfide with one of the metals, and then completing the neutralization by treatment with a suitable basic compound of the other metal desired. Another method by which the mixed salts may be prepared consists in first preparing an alkali metal salt of the alkylated phenol sulfide and then reacting this salt with a mixture of alkaline earth metal salts, e. g., a mixture of the chlorides of the metals in question. For the best results, the proportion of metal compounds employed should be such that the final product contains at least 15% of each metal on a molecular basis, related to the total metal content of the salts.

Methods of preparing various single metal and mixed metal salts of the alkaline earth metals and tests of the performance of lubricants 'con taining such compounds are described in the following examples, which are intended to be illustrative only and not as limiting the scope of the invention in any way.

Example 1.-C'alcium salt of tert.-octyl phenol sulfide The following materials were blended together and added to a nickel reactor: 952 grams tert-.- octyl phenol sulfide (prepared b alkylating phenol and diisobutylene and reacting the product with S012), 152 grams stearyl alcohol, 1370 grams solvent extracted Mid-Continent paraffinic oil of 52 seconds viscosity Saybolt at 210 F. A slurry of 185 grams of commercial lime (CaO) and 500 grams of waterwere added to the product, and the whole mixture was heated with stirring at the reflux temperature for 24 hours. The reaction product was then removed, blown dry with "nitrogen, and filtered through Hi-flo filter aid. Analysis showed the resulting concentrate to contain the following: Ash 8.09%, calcium 2.66%, sulfur 4.09%.

Example 2.-Strontium salt of ten-octyl phenol sulfide The following materials were blended together and added to a reaction flask: 468.5 grams tert.- octyl phenol sulfide (prepared as in Example 1), 81.4 grams s'tearyl alcohol, 732.0 grams of a solvent extracted Mid-Continent paraffinic oil of 52 seconds viscosity Saybolt at 210 F. 306 grams of strontium hydrate (SI(OH)2.8H2O) was slowly added over a period of 2 hours to the mixture in thefiask at C. and then held at this temperature for an additional 4 hour period with rapid stirring. The contents of the flask was then dried by blowing with nitrogen at C. and then filtered through Hi-no filter aid. The product contained the .following by analysis: Ash 14.11%, strontium 7.02%, sulfur 3.58%.

Example 3.Barium salt of tert-ozctyl phenol sulfide The following materials were added to a reaction flask equipped with a water condenser and mechanical stirrer: 468.5 grams of tert .-octyl Mid-Continent parafiinic oil of 52 seconds viscos ity Saybolt at 210 F. The mixture was heated to 125 C. and 350 grams of barium.- hydrate,

(Ba(OH)2.8HzO), added slowly over a period of 6 hours at nil-130 C. The roauctwss dried by blowing with nitrogen as: afioutnne liourjat 140 0., and filtered through in-no" filter aid;

The product contained the following by analysis:

Ash 15.27%, barium 9.31%, su1phi1r 3.27%'.

Example 4.Calcium-strontium salt of "teftl: octyl phenol sulfide Analysis showed it to contain the following:

.45%, calcium 2.63%, Stfhfitfih 639%, sulfur 3.72%; H Example 5.--Calcz'um+buri um;sult of tertoct'yl phenol sulfide 1500 grams of the-tanner saltconcentrate; prepared as in Example 1, containing about 85% of the theoretical amountpi calcium required to neutralize the alkyl phenolsulfide, was placed in a reaction flask and heated to 125 C. '70 grams of barium hy rate Ba onitsHto3= added with" rapid st rring over a period oi 2 hours; The mixture was then Blown with nitfogenat l 5 [}f- C. to dry the same" and theh-filtred' through Hi-no" filte'raid; The 'product contained the following: 10.17%, calcium 2,56%, barium 1.91%, sulfur 3.85%.

Ewample 6 the following P5136 m pi t nb e n b se ls solvent extracted Mid-Continent p aflinic oil of SAE sot/nasty gramme of ,var

consisting or u this on with the. auntie each of the various salts prepardas described iii.

the preceding examples, were tested iii a single cylinder Caterpillar engine, each run being heads for 120 hours at 1000 PYM. with approximate- 2. b k 19 1 P wer o il em er tnrefof 1 25450? F. and a jacket tem eratureof 175-180 F, At the end oi each tst thering' Zone ofrt he engine was; iiispectejd and givefi a cement rating based on the condition observe demerit rating of zero represents a c ndit oawnerein thereare no deposits'an'd a demerit rating of 10 repres nts tnemaximum deposit hat pants, termed in the test engine, Cons q ently, dihrit ratings indicate. better engine cori ti an M hence a better perro ;c of the n i engine. In preparing the blends for this tstthe concentr tes described in the precedingjexainpies were employed, each something about 49% 6t th alkyl phenol sulfide salt. Amounts were used to produce in each case a blend containing 1% of the salt. The results of these engine tests are shown in the following table:

on Blend gig fl Base 0il -Q Q. l 1. 91 Base Oil +1% calcium salt (product of Ex. 1)". l. 47 Base Oil +1% strontium salt (product of Ex. 2) 0.92 Base Oil +l% barium salt (product of Ex. 3) 1. 47 Base Oil +1% calcium-strontium salt (product of 0 4g 7 x. Base Oil +l% calcium-barium salt (product of Ex. 5) 0. 83

The products of the present invention may be employed not only as the sole additives in hydrocarbon lubricating oils but also in conjunction with other detergent type additives such as metal sulfonates, metal soaps, metal phenates, metal alcoholates, metal phenol sulfonates, metal alkyl phenol sulfides, metal organo phosphates, thlophosphates, phosphites and, thiophosphites, metal salicylates, metal X'anthates' and thioiin: that'e s, metal thioc'arbamates, aminesanq amine derivatives, reaction products ofr'rietal phenst'es' or metal phenol sulfides withs'ulfur; reaction products" of metal phenats or metal phenol. siil-Q fides with phosphorus sulfides, fel'iid the use. Thusthe new additives of this'ifivfitioiililiayb used in lubricating oilscontaining" suchfadditioh' agent as nickel oleate, barii'iinootadecylate',,calcium phenylstearatalzinc diiso'profiyl salibylat', aluminum naphthenate, calcium ctyl phosphate, barium di-tert.-amyl phenol sulfide}. calcium petroleum sulfonate', zincmtl'iyl cycloh'eiiyljlthiophosphate, calcium dichloros tearatlgetc, l

-' and/or clay or other'agents such as aluminum chloride, or they may be extracted ens-produced, for example, by solventextractionlwith solvents of the type of phenol, sulfur. dioxide, furfiii 'al, diehlorodiethylether, nitrobehzen, 'crotonalder hyde, etc. Hydrogenated oilslo'r white oils'may be employed as well assynthet'ic oils' prepared, for" example, by the polymerizationof olefiiisfii the reaction of oxides of carbon with hy rogen or" by the hydrogenation of coal" or its products. Q In certain instances cracking coil tari fractlons' and coal tar or Shale oil distillates ma also be used. Also, for spec ial applications, animal} vegetable, or fish oils or their hydrogenated for voltolihed products may beemployed, eitheralorie of in ad minturewith mineraloils'.

For the best results the base. stock chosen should normally be that cil which Withoiitlth' new additives. present gives the optimum erformarl'ce in the service contemplated ,.How

' ever, since one advantage of the additives islthat their use also makes feasible'the employment of lesssatisfactory minefial oils or other oils, no strict rule can be laid down for the Choice of the base stock. Certain essentials must of, course, be observed. The. oil must possess the viscos ty and' volatility characteristics known to be 1 18: quiredfor the service contemplated; The 611, must bea satisfactory solvent for the additive, although, in some cases auxiliary solvent agents may be liSd. Th lubricating oilshowver they may have been produced, may vary considerably in viscosity and other properties depending upon the particular use for which they are desired, but they usually range from about 40 to 150 seconds Saybolt viscosity at 210 F. For the lubrication of certain low and medium speed Diesel engines the general practice has often been to use a lubricating oil base stock prepared from naphthenic 0r aromatic crudes and having a Saybolt viscosity at 210 F. of 45 to 90 seconds and a viscosity index of 0 to 50. However, in certain types of Diesel service, particularly with high speed Diesel engines, and in gasoline engine service, oils of higher viscosity index are often required, for example up to 75 or 100, or even higher, viscosity index.

In addition to the materials to be added according to the present invention, other agents may also be used such as dyes, pour depressors, heat thickened fatty oils, sulfurized fatty oils, organo-metallic compounds, metallic or other soaps, sludge dispersers, antioxidants, thickeners, viscosity index improvers, oiliness agents, defoaming or antifoaming agents, resins, rubber, olefin polymers, voltolized fats, vol tolized mineral oils, and/or voltolized waxes and colloidal solids such as graphite or zinc oxide, etc. Solvents and assisting agents, such as esters, ketones, alcohols, aldehydes, halogenated or nitrated compounds, and the like may also be employed.

Assisting agents which are particularly desirable as plasticizers and defoaming agents are the higher alcohols having eight or more carbon atoms and preferably 12 to 20 carbon atoms. The alcohols may be saturated straight or branched chain aliphatic alcohols such as octyl alcohol (CsHnOH), lauryl alcohol (C12H25OH), cetyl alcohol (C1sH33OH), stearyl alcohol, sometimes referred to as octadecyl alcohol, (CmHmOH), and the like; the corresponding olefinic alcohols such as oleyl alcohol; cyclic alcohols, such as naphthenic alcohols; and aryl substituted alkyl alcohols, for instance, phenyl octyl alcohol, or octadecyl benzyl alcohol or mixtures of these various alcohols, which may be pure or substantially pure synthetic alcohols. One may also use mixed naturally occurring alcohols such as those found in wool fat (which is known to contain a substantial percentage of alcohols having about 16 to 18 carbon atoms) and in sperm oil (which contains a high percentage of cetyl alcohol); and although it is preferable to isolate the alcohols from those materials, for some purposes the wool fat, sperm oil or other natural products rich in alcohols may be used per se. Products prepared synthetically by chemical processes may also be used, such as alcohols prepared by the oxidation of petroleum hydrocarbons, e. g., paraflin wax, petrolatum, etc.

The present invention is not to be considered as limited by any of the examples described herein, which are given by way of illustration only, but is to be limited solely by the terms of the appended claims.

We claim:

1. A mineral lubricating oil containing dissolved therein about 1 of a mixed alkaline earth metal salt of an alkylated phenol sulfide having an alkyl side chain of 4 to 8 carbon atoms attached to each benzene nucleus, the metal content of the salt consisting of 15% to of calcium and 85% to 15% of a metal selected from the group consisting of barium and strontium, the percentages being molecular amounts, related to the total amount of metal required to neutralize the said alkylated phenol sulfide.

2. A composition according to claim 1 in which the alkyl side chains of the alkylated phenol sulfide are tertiary octyl groups.

3. A composition according to claim 2 in which the metal content of the salt consists 'of about 85% of calcium and about 15% of a metal selected from the group consisting of barium and strontium, on a molecular weight basis.

4. A composition according to claim 3 in which the salt contains about 85% of calcium and about 15% of barium on a molecular weight basis.

5. A composition according to claim 3 in which the salt contains about 85% of calcium and about 15% of strontium on a molecular weight basis.

JOHN G. McNAB. GEORGE M. McNULTY. THOMAS CROSS, JR.

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

UNITED STATES PATENTS Number Name Date 2,249,626 Cook July 15, 1941 2,331,448 Winning Oct. 12, 1943 2,342,887 Nelson Feb. 29, 1944 2,346,826 Cook Apr, 18, 1944 2,362,292 McNab Nov. 7, 1944 2,399,877 McNab May 7, 1946 2,399,878 Van Gilder May 7, 1946 2,406,041 Schneider Aug. 29, 1946 2,409,687 Rogers Oct. 22, 1946