Patented Oct. 22, 1946 2,409,877 UNITED STATES PATENT OFFICE _ 2,409,877 wnnrcarmo on. Robert L. May, Chicago, Ill., asslgnor to Sinclair Re?ning Company, New York, N. Y., a corpora tion oi’ Maine No Drawing. A'pplication July 15, 1944, Serial No. 545,193 4 ‘Claims. (Cl. 252-46.?) This invention relates to a lubricating oil com 2 various other organic calcium salts have been position ' having improved characteristics espe found particularly e?ective as detergents in lubri cially with respect to oxidation and corrosion. cating oil compositions used in internal combus My improved lubricating oil composition may be tion engines, the two particularly named calcium used with particular advantage as a heavy duty 5 compounds being more fully described in Letters oil lubricant for gasoline and Diesel engines, and Patent 2,347,547 and 2,339,692, issued on applica~ , is also particularly desirable as a turbine oil, as tions of Willard L. Finley. an hydraulic ?uid or for like purposes. A further highly effective lubricating oil com In my Patent 2,379,312, I have described and position contemplated by my present invention claimed a novel class of compounds resulting from 10 is one comprising, in addition to the lubricating the reaction of an alkylated phenol with the con densation product of a terpene, such as present in turpentine, and phosphorus pentasul?de, P285. The turpentine-P285 condensation product is the _, oil constituents and my inhibitor, a calcium pe troleum sulfonate, as a. detergent. Other deter gents which may be used with advantage include the barium phenolate of sulfurized diamyl phenol, subject of my co-pending application Serial No. 15 such as currently marketed under the trade name ' “Aerolube B,”‘metallic phenolatcs of sulfurized I have now discovered that the compounds _ ' tertiary amyl phenol, such as currently marketed which my Patent 2,379,312 is directed are espe under the‘trade names “Calcium Paranox” and cially eifective in repressing or inhibiting the “Barium Paranox," and various other metallic deterioration of lubricating oil compositions and 20 soaps, either basic or neutral, metallic sulfonates, 494,688, filed July 14, 1943. the corrosion of metal parts in contact therewith. alcoholates and alkoxides and metallic deriva I am at present unable to de?nitely de?ne by tives of alkylated salicylic acid. _ chemical formula either the condensation prod When used in conjunction with these deter ucts of turpentine and P285, or the products re gents, particularly the calcium salts, including sulting from the reaction of said condensation 25 the calcium petroleum sulfonates previously men products with the alkylated phenols. For brevity, tioned, these detergents and my inhibitors have I shall herein refer to the former as the turpen been found to complement each other, so that tine-P285 condensation product and to the com the effectiveness of each is promoted. For ex pounds resulting from the reaction of said con ample, the phosphorus acidity of the inhibitor densation products with the alkylated phenols as 30 appears to be neutralized by the calcium. of the my inhibitor. detergent, thus minimizing any tendency of the The characteristics of the inhibitor used in the former to promote sludge formation. Further the compounding of the lubricating oil composition tendency of the detergent to promote oxidation of of my present invention vary somewhat depending the oil at the termination of its oxidation induc— upon the characteristics of the turpentine-P285 tion period is also minimized by the presence of condensation product and the nature and pro my inhibitor. Each of these desirable ends is portions of alkylated phenol used in its prepera accomplished without destroying the e?'ectlveness tion. Generally, these compounds are relatively of either the detergent or the inhibitor. acidic and are highly soluble in mineral oils. The proportions of the inhibitor used in the The lubricating oil composition of my present 40 compounding of my improved lubricating oil com invention may consist solely of the lubricating oil positions may be varied somewhat but, in any constituent and my inhibitor. However, the in case, only a minor proportion is used. The opti hibitors of my present invention have been found mum proportion to be used will depend upon to be compatible with other desirable lubricating whether or not a detergent, such as previously oil addends and the inclusion of such other ad mentioned, is present and the particular use to dends, especially addends of the type known as de which the lubricating oil composition is to be tergents, is within the contemplation of my pres put. The optimum proportion will also vary, de ent invention and constitutes an important aspect pending upon the particular member of my new thereof. class of inhibitors used. The inclusion of certain so-called detergents, 50 In the preparation of my improved lubricating for instance, in internal combustion engine lubri oil composition, I have found it advantageous to cants, has been found highly advantageous. An prepare the inhibitor in solution in about an equal especially e?’ective lubricating oil composition for weight of a petroleum lubricating oil fraction, the lubrication of internal combustion engines, as hereinafter more fully described. As a motor and the like, contemplated by the present inven 55 oil which does not contain detergents, 0.2 to 0.5% tion, is one comprising, in addition to the lubri of the 50% concentrate of my inhibitor may, cating oil fraction and my inhibitor, a minor pro with advantage, be admixed with the lubricating portion of a calcium-containing detergent, for oil constituent. When used as an anti-oxidant instance, a calcium salt of iso-octyl salicylate, or in turbine oils or hydraulic oils, the 50% con a. calcium salt of capryl salicylate. These and 60 centrate may be added to the lubricating con 2,409,877 3 4 stituent in proportions advantageously ranging from about 0.1 to about 0.3% by weight. In ‘heavy duty oils containing detergents, such as istics of the turpentine-P285 condensation prod uct used in its preparation and the nature and proportions of the alkylated phenol reacted there with, the illustrations of my lubricating oil com previously mentioned, for use in gasoline or Diesel engines, the 50% concentrate of my inhibitor may, ' positions will include a description of the prep with advantage, be added in proportions ranging from about 1% to about 5% by weight, depending aration of the particular inhibitor used. In the preparation of the intermediate tur pentine-P285 condensation product to be used upon the nature and concentration of the deter gent, the severity of the service for which the in preparing my inhibitor, the molar ratio of lubricating oil composition is to be used and the 10 turpentine to Pass used is with advantage ap particular inhibitor employed. proximately 3:1, though this ratio may be varied somewhat as subsequently described. ' However, these inhibitors are acidic phosphorus derivatives and phosphorus acidity has been The reaction of turpentine with P235 is highly exothermic and proceeds spontaneously after found to have a general tendency to‘ promote polymerization and sludge formation in mineral 15 being initiated by slight heating. A desirable lubricating oils. In internal combustion. engine method of effecting the reaction is to heat the turpentine in a vessel to about 200° F. or slightly lubricants, where sludge formation must be mini mized, the use of the inhibitor in proportions .ex higher and then, without further heating, slowly stirring in the phosphorus pentasul?de in the ceeding about 1% by weight, in the absence of de tergents such as previously noted, is not generally 20 powdered form. The heat of reaction is great advisable. However, proportions within the in and, consequently, the addition should be made dicated range will be found not to cause noticeable slowly, so as to avoid the possibility of the reac or objectionable sludging under such conditions. tion's becoming uncontrollable. The character istics of the inhibitor are favorably affected by In gear lubricants, for example, where polymer ization and sludging is less critical, larger pro 25 using in its preparation a turpentine-Pass con portions of the inhibitor may be employed. densation product in the preparation of which For optimum results, when used in conjunction the temperature during the mixing was not with one of the previously-noted calcium deter permitted to exceed about 250° F., although gents, the proportion of the inhibitor should gen higher temperatures are permissible. erally not exceed that which will be neutralized 30 After the addition is completed, it is usually by the calcium salt detergent, for, with an ex necessary to apply heat externally to complete cess of the inhibitor, residual phosphorus acidity the reaction. The temperature during this last will remain with its characteristic tendency to stage is preferably maintained at about 300° F., promote sludge formation. The optimum ratio though temperatures of about 200° F. to 400° F. of the inhibitor to the detergent will depend upon 35 may be employed. This second stage of the the basicity of the detergent and upon the amount operation should be continued until all of the of P255 equivalent, used in the preparation of the P235 is dissolved. The material thus prepared inhibitor, and may be determined for any partic is a viscous liquid at elevated temperatures ular set of conditions by simple test. which solidi?es on cooling to room temperature. Various petroleum lubricating oil fractions may 40 The turpentine-P285 concentration products, thus prepared, are, in the absence of excess be used, for instance, solvent-treated Mid-Con tinent neutrals or a blend of such Mid-Continent turpentine, brittle, resinous solids which‘ dis neutrals with bright stock or a. solvent-re?ned solve readily in lubricating oils or in excess tur lubricating oil fraction from a Pennsylvania pentine to form liquids. Such solutions of high crude. Characteristics of two lubricating oil con 45 concentration are relatively viscous. However, the viscosity of the solution decreases rapidly stituents which have been used with advantage, as the proportion of the solvent is increased from and which were used in the compounding of the - lubricants hereinafter set forth as illustrative of 25% to 75%. my invention, appear in the following Table-I, in In general, my inhibitor may be prepared by which base oil-A is a solvent-treated Mid-Conti 60 adding the alkylated phenol gradually to the nent, S. A. E. 10 oil and base oil B is a sulfonated turpentine-P285 condensation product prepared Mid-Continent S. A. E. 30 oil prepared by treat ‘ as previously described. Such addition is ad ing a raw Mid-Continent stock with 40 pounds vantageous at a temperature of about 230° F. of 99.3% sulfuric acid per barrel, separating the However, this temperature may be varied, tem- , sludge formed, neutralizing the acid oil with 55 peratures as high as 300° F. being used without lime, heating the mixture to drive oil.’ all water damage to the product. present and ?ltering the dehydrated oil. In reacting the alkylated phenol with the tur pentine-P285 condensation product, very little Table I heat is evolved. After the alkylated phenol has been added, the mixture is maintained at an Base oil A Gravity, ° A. P. I. ' The proportions of the alkylated phenol may 25.5 Flash, ° F _______ __ 435 Fire, ° F ________________ __ Viscosity at 100° F. SUS. _ elevated temperature, advantageously about 200° F. for about an hour with‘ stirring.‘ B 500 249. 6 512. l 49. 0 60. 2 be varied over a considerable range without loss of the effectiveness of the resulting inhibitor. The optimum proportion of alkylated phenol used is, to a considerable extent, dependent upon Viscosity index _______ __ 92. 8 77.0 ,the ratio of turpentine to P285 used in the prep Pour, “F ...... __ 5 5 aration of the intermediate condensation prod Percent sulfur..." -__ 0. 20 0. 35 Percent calcium __________________________________________ _ _ 0. 061 70 uct. Particularly desirable results’ have been obtained using proportions of. reactants equiv The invention will hereinafter be illustrated alent to about .2 moles of P235, 6 moles of tur by speci?c examples of my improved lubricating pentine and 3 moles of alkylated phenol, assum oil composition. Since the characteristics of the ing the molecular weight of turpentine to be 136. inhibitor are somewhat affected by the character 76 However, the proportions of these constituents Viscosity at 210° F. SUS 2,409,877 6 may be varied somewhat. Satisfactory results stood, however, that my invention is not limited to lubricating oil compositions containing the par ticular inhibitors illustrated. may- be obtained where for each two moles of P255, 5 to 7 moles of turpentine and 1 to 5 moles of the alkylated phenols are used. However, I have found it desirable that the total number ExAMPLE I‘ of moles of turpentine and alkylated phenol used 2040 grams of turpentine was placed in a ?ask for each two moles of P285 fall within a range of equipped with stirrers, a thermometer and a fun about 8 to 10. Also, in the preparation of the nel and heated to a temperature of 240% F. turpentine P285 condensation product used in There was then slowly added with stirring 1110 preparing the inhibitor, I have found it desir 10 grams of powdered phosphorous pentasulflde at able that no unreacted P255 remain in the a rate such that the temperature of the mixture product. did not ‘rise above 275° F. After all of the phos In the preparation of my new class of inhibi phorus pentasul?de had been added, the temper tors, considerable latitude 'is permissible in the ature of the mixture was raised to 300° F. and selection of the alkylated phenol used. In general, 15 maintained at this temperature for 2 hours, at the alkyl radical of the alkylated phenol should the end of which period all of the Pass had dis be a saturated aliphatic group. Each molecule solved and the product was a viscous amber of the alkylated phenol may contain one or more colored liquid. This turpentine-P255 condensa such groups. The number of carbon atoms in tion product was then cooled to 230° F. and 1230 ' each aliphatic group is not critical. Desirable 20 grams of p-tert-amylphenol was added and the products may be obtained where each such group mixture heated for 1 hour at a temperature of contains from 1 up to 12 to 16, or even up to 200° F. with stirring. The resulting product 25 to 35 carbon atoms. Alkylated phenols con was found by analysis to have an acid number taining 5 or more carbon atoms in each alkyl of 46.5 and a saponi?cation number of 132.1, and group have been found especially desirable in 25 to contain 6.82% phosphorus and 17.4% sulfur the preparation of my new inhibitors, because of 4380 grams of this product was admixed with the great-oil solubility of the resultant products. 4380 grams of a light petroleum lubricating oil The alkyl group or groups may be either normal or branched ‘chain. ' fraction having the characteristics set forth in the following Table II. The 50% concentrate I Alkylated phenols, herein designated codimer thus prepared was found by analysis to have an alkylated phenols, such as- prepared by the re 30 acid number of 30, a saponi?cation number of 65.5 action, in the presence of sulfuric acid, of phe and an A. P. I. gravity of 11.4 and to contain nols with the ole?nes in commercial codimer, 3.42% phosphorus and 9.55% sulfur. resulting from the phosphoric acid polymeriza EXAMPLE II per molecule and comprising propylene, butene To a turpentine-P285 condensation product, 1, butene-2 and lso-butylene, the codimer con prepared as described in the foregoing example sisting of a major portion of Ca ole?nes, together from 1632 grams of turpentine and 888 grams of P285, at a temperature of 300° F. there was added with some C8, C1, ‘C9, C10, C11, C12 and higher ole?nes, have been used with advantage. These 40 1404 grams of diamylphenol, and the mixture codimer alkylated phenols are comprised pri heated at 250° F. for 1 hour with stirring. To marily of mono- and poly-alkylated phenols the resulting product there was added 3,924 having alkyl groups, as noted above, but with Ca grams of the base oil used in Example I to pro alkyl groups predominating. duce a 50% concentrate which was found by I have further used with advantage in the 45 analysis to have an acid number of 27.5, a saponi preparation of my improved inhibitors, alkylated ?cation number of 60.7 and an A. P. I. gravity of tion of mixed ole?nes of 4 carbon atoms or less 35 phenols, herein designated codimer bottoms alkyl ated phenols, herein designated codimer bottoms alkylated phenols, prepared by the method just described for the preparation of codimer alkyl ated phenols except that'the phenol was reacted with codimer bottoms, the codimer bottoms used being the bottoms obtained by a redistillation of 13.4, and to contain 3.04% phosphorus and 8.30% of sulfur. 50 EXAMPLE III To a turpentine-Pass condensation product, prepared as in Example I from 2040 grams of tur pentine and 1110 grams of P285, at a temperature of 230° F. there was added 1425 grams of a butene the previously described codimer to a 350 to 360° alkylated phenol having a phenol number of F. end point overhead. This bottoms was com 55 294.3 and an apparent molecular weight'of 190. prised primarily of C12 ole?nes, but contains some somewhat lower and some somewhat higher molecular weight ole?nes. , In the preparation of the turpentine-P285 con densation product, either steam-distilled wood turpentine or gum spirits may be used. Such tur pentine consists mainly of alpha pinene, a bi cylic terpene having the empirical formula CIOHIG - The mixture was heated at a temperature of 200° F. for 1 hour with stirring. The resultant prod uct was found by analysis to have an acid number of 57.5, a saponi?cation number of 136.0 and to 60 contain 7.13% of phosphorous and 17.82% sulfur, 4575 grams of the product prepared as described was thoroughly blended with an equal weight of the light petroleum lubricating oil fraction used Pure alpha pinene and other more costly ter in Example I to produce a 50% concentrate of penes will react similarly with P255, but, for 65 the inhibitor. This concentrate was found by reasons including economic considerations, I pre analysis to have an acid number of 30.3, saponi fer to use the more readily available turpentines. The turpentine used in the speci?c examples ?cation number 01’ 65.6 and an A. P. I. gravity of 12.2 and to contain 3.75% phosphorus and 9.31% sulfur. turpentine comprising about 90% alpha pinene. EXAMPLE IV The following speci?c examples of inhibitors 70 To a turpentine-P255 condensation product used in the compounding of my improved lubri prepared as in Example I, from 2040 grams of cating oil compositions and the procedure by turpentine and 1110 grams of P285, there was which such inhibitors may be prepared are given added 1700 grams of a codimer alkylated phenol as illustrative of my invention. It will be under 76 having a phenol number of 247.4 and an apparent herein was a technical grade steam-distilled wood 2,409,877 ‘8 7 molecular weight of 227. The mixture was re acted by heating at a temperature of 250° F. for 1 hour with stirring. 4850 grams of the product thus prepared was then intimately blended with an equal weight of the petroleum lubricating oil fraction of the type used in Example I to pro duce a 50% concentrate of the inhibitor. This concentrate was found by analysis to have an acid number of 25.8, a saponi?cation number of 61.6 and an A. P. I. gravity of 12.6 and to contain 10 3.22% phosphorus and 8.63% sulfur. apparent molecular weight of 448. The mixture was heated for 1 hour at 200° F. with stirring. The product was found by analysis to have an acid number ,of 45.8 and a saponi?cation number of 98.0 and to contain 4.82% phosphorus and 12.68% sulfur. Exzmru: X A. turpentine-P255 condensation product, pre pared as in Example I, from 1632 grams of tur pentine and 888 grams of PzSs, was reacted as previously described with 2570 grams of codimer EXAMPLE V bottoms alkylated phenol consisting of equal pro portions of a codimer bottoms alkylated phenol To a turpentine-Pass condensation product having a phenol number of 134.9 and an apparent prepared as in Example I from 816 grams of tur molecular weight of 415 and a codimer bottoms pentine and 444 grams of P285. there was added alkylated phenol having a phenol number of 127.5 1293 grams of a codimer bottoms alkylated phenol and an apparent molecular weight of 441. The having a phenol number of 129.6 and an apparent product was found by analysis to have an acid molecular weight of 432. This mixture was caused to react by heating at a temperature of 20 number of 40 and a saponi?cation number of 97.1 and to contain 4.72% phosphorus and 12.12% ' 200° F. for one hour with stirring. The product sulfur. was then diluted and intimately blended with an The light petroleum lubricating oil fraction equal weight of the petroleum lubricating oil 'used as the diluent in various of the foregoing fraction used in Example I to produce a 50% concentrate of the inhibitor. This concentrate 25 speci?c examples was a Mid-Continent neutral having the characteristics set forth in the follow was found by analysis to have an acid number of 17.5, a saponi?cation number of 43.0 and an A. P. I. gravity of 16.3, and to contain 2.78% phosphorus and 6.87% sulfur. ing table: Table]! Gravity, °A. P. I_..__.. _________________ __ 27.9 365 30 Flash, °F EXAMPLE 'VI Fire, °F ______________________________ __ 405 To a turpentine-P285 condensation product, Viscosity at 100° F., SUS_______________ .. 107.8 prepared as in Example I from 2040 grams of tur ‘Viscosity at 210° F., SUS ______________ __ 39.5 pentine and 1110 grams of P285, cooled to a tem Pour,v °F 20 perature of 230° F., there was added 1755 grams 35 Color 2__ of diamyl phenol and the mixture heated with The codimer alkylated phenol and the codimer stirring for about 1 hour at a temperature of 190 bottoms alkylated phenol were those previously to 200° F. The product was found by analysis to described herein. ‘ have an acid number of 51.2, a saponi?cation For the purpose of further illustrating my in number of 120.4 and to contain 6.26% phosphorus 40 vention and the advantage derived therefrom, I and 16.3% sulfur. have herein set forth the results of oxygen ab EXAMPLE VII sorption and bearing corrosion tests of various of my improved lubricating oil compositions. The A turpentine-P285 condensation product, pre advantages of my present invention with respect pared as in Example I from 2040 grams of tur pentine and 1110 grams of Past. was admixed 45 to oxidation and corrosion characteristics of my improved lubricating oil compositions are illus with 2050 grams of codimer alkylated phenol hav ing a phenol number of 203.7 and an apparent trated by their mean oxygen absorption rates, as compared with the oxygen absorption rates of the molecular weight of 275 and the mixture heated at 200° F. for 1 hour with stirring. The product base oil, and the corrosion losses of bearing metal . was found by analysis to have an acid number 50 in contact with the respective lubricants. These tests were carried out in a closed system of 51.3 and a saponi?cation number of 117.6 and in which pure oxygen was circulated through to contain 3.98% phosphorus and 15.82% sulfur. 156 grams of the lubricant being tested. The pressure of the system was maintained constant A turpentine-P285 condensation product, pre- ,55 by introducing oxygen from a burette, and the sample was maintained at 360° F. and in contact pared as in Example I from 1632 grams of tur with two pieces of copper-lead bearings having pentine and 888 grams of P285, was reactedas an approximate combined area of one square inch previously described with 2149 grams of a codimer of copper-lead alloy surface and one square inch bottoms alkylated phenol having a phenol num ber of 151.2 and an apparent molecular weight of 60 of steel surface. The rate of oxygen absorption is calculated as milliliters of oxygen absorbed per 371. The product was found by analysis to have minute per 100 grams of oil, measuring the an acid number of 45.5, a saponification number oxygen under standard condition of temperature of 104.5 and to contain 5.15% phosphorus and and pressure. The bearing corrosion loss is re 13.93% sulfur. EXAMPLE VIII » ExAurLn IX ‘ 65 ported as milligrams, the plus sign indicating gain in weight. When subjected to the foregoing test, the mean pared as in Example I from 2040 grams of ‘tur oxygen absorption rate of base oil A, previously pentine and 1110 grams 01' Pass, was admixed identi?ed, was 25.6 milliliters, and the bearing with 2670 grams of codimer bottoms alkylated 70 corrosion loss was 5.8 milligrams. By incorporat phenol consisting of equal proportions of a codi ing in this base 011 0.1% of my inhibitor prepared mer bottoms alkylated phenol having a phenol as described in Example 11, the mean oxygen ab A turpentine-Pass condensation product, pre number of 125.9 and an apparent molecular sorption rate was reduced to 9.5 milliliters and weight of 445 and a, codimer bottoms alkylated the bearing corrosion loss reduced to 5.2 milli phenol having a phenol number of 124.7 and an 75 grams. By compounding with this same base oil 2,409,877 10 0.25% of said inhibitor, the mean oxygen absorp tion rate was reduced to 2.0 milliliters and the noted, for instance, calcium petroleum sulfonates. However, the latter compositions are particularly there being an increase in the bearing weight of . The proportions of inhibitor indicated as used .> or also contains a detergent, such as previously bearing corrosion loss completely eliminated, 1.2 milligrams. i the lubricating oil constituent and my inhibitor ‘in ‘ in each of the tests herein are based on the advantageous, as previously noted herein. I claim: ‘ 1. A lubricating oil composition comprising a major proportion 01' a petroleum lubricating oil from the 50% concentrate previously described. and a minor proportion, effective to retard oxida Further illustrations of my improved lubricat tion of the oil, of an inhibitor resulting from the ing oil compositions and the characteristics reaction of an alkylated phenol with the conden thereof with respect to oxygen absorption rates sation product of turpentine and phosphorus and bearing corrosion losses are set forth in the » pentasul?de. the alkyl group of the alkylated following Table III. In each instance, the inhibi tor was compounded with previously identified 15 phenol being a saturated aliphatic radical 2. A lubricating oil composition comprising a base oil B, the characteristics of base oil B with major proportion of a. petroleum lubricating oil out the inhibitor being included for comparison. and about 0.1 to 2.5%, based on the weight of the Table III oil constituent, of an inhibitor resulting from the weight of the undiluted inhibitor, as distinguished Inhibitor . Identity Noni‘ . . _ _ _ _ . . . _ Example I ____________ -_ Example VI __________ _- . Prp‘g‘getlll‘zn’ . _ _ . _ ._ l\/(l’)e,a;1b;rli)tri;]of Deming mm- W est.‘ it: . 100 Q mgs. reaction of an allqrlated phenol with the con 20 densation product of turpentine and phosphorus pentasul?de, the alkyl group of the alkylated phenol being a saturated aliphatic radical. , , 21. 6 9.8 0.1 0.1 4.08 3. 80 +1. 5 +0. 6 0.1 0.1 0. 1 0.1 0. l 4. 28 3. 74 4. 15 3.19 4. 07 +0. 2 +2.0 +1. 5 +1. 2 +1. 7 _ 3. A lubricating oil composition comprising a major proportion of a petroleum lubricating oil 25 and a minor proportion, effective to retard oxl_ dation of the oil, of an inhibitor resulting from the reaction of diamyl phenol with the condensa tion product of turpentine and phosphorus penta sul?de. 30 4. A lubricating oil composition comprising a major proportion of a. petroleum lubricating oil From the results of these tests, it appears that and a minor proportion, e?'ective to retard oxida though the base oil had high corrosion rates and tion of the oil, of an inhibitor resulting from the high oxygen absorption rates, the lubricating oil compositions prepared therefrom, in accordance 35 reaction of an alkylated phenol with the conden sation product of turpentine and phosphorus with my invention, showed in each instance sub pentasul?de, the alkyl group of the alkylated stantially reduced oxygen absorption rates and phenol being a saturated aliphatic radical con— bearing corrosion losses. These results are ob taining at least 5 carbon atoms. tained where the composition consists solely of ROBERT L. vMAY.