US2169634A - Lubricating oil compositions, inhibitors therefor, and methods of manufacturing the same - Google Patents

Description

Patented Aug. 15, 1939 OFFlC LUBRICATING on. COMPOSITIONS, INHIBI- TORS THEREFOR, AND METHODS OF MAN- UFACTUKING THE SAME Troy Lee Cantrell and James Otho Turner, Lansdowne, Pa., assignors to Gulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania No Drawing. Application Septemberv 17, 1936, Serial No. 101,340. Renewed December 14,

8 Claims.

Our invention relates to lubricating oils and more particularly to lubricating oil compositions containing an oil-soluble agent or agents effective to inhibit or mitigate the normal corrosive 5 or destructive action of lubricating oil deterioration products upon certain types of bearing metals under certain conditions of use, said agent or agents also having the properties of imparting so-cailed extreme pressure characteristics to 10 thelubricating oil compositions, and also being effective to reduce or eliminate undesirable oxidation changes in the oil. 7

Despite the many technological advances made in the art of refining and applying lubricating oils and in the composition .of .bearing materials, modern lubricating oils and bearings often fail to perform satisfactorily. It is well known in the art that straight petroleum lubricants have fairly well defined limits of bearing speeds, pressures,

and temperatures within which they will give acceptable service. These limitations are often ex-- ceeded in modern designs, resulting in machines that cannot be satisfactorily lubricated by straight mineral oils. These modern designs are justified by engineers in their efforts to provide machines to conform to theever-increasing demand for compactness, speed; power and acceleration in modern engines. 'Many modern designs have already exceeded the above-mentioned lim-. 'its wherein straight petroleum lubricating oils perform acceptably; therefore, it is necessary to provide lubricating compositions that extend and widen the limits formerly associated with straight lubricating oils.

Moreover, highly paraflinic Oils having excellent viscosity-gravity constants, volatilities; carbon residue values, and resistance to sludging and oxidation, and hence of high value for use under relatively mild lubricating conditions, sometimes tend to be even less satisfactory thanthe less highly parafiinic oils, when theordinary limits of temperature, pressure, and bearing speed are exceeded. This may be due in part to the fact, that the deterioration products of paraflinic constituents are more active than those resulting from naphthenic or other nonparaflinic constituents, and it may be due also to the fact that the nonparaffinic constituents have some inhibitin effect upon either the'cleterioration of the para!- finic constituents or upon the behavior of prod- 5 ucts resulting from such deterioration, at high temperatures and pressures and in the presence of certain metals. However, the inhibiting value of the nonparaflinic constituents is low per unit concentration, and they are less satisfactory with respect to viscosity-gravity constant, carbon residue, and similar criteria of lubricating quality than the paraifinic constituents. A more satisfactory solution of the problem would be to substitute for the nonparaflinic constituents removed in the more drastic refining treatments or absent because of the highly paraflinic nature of the original stock, some inhibiting or mitigating agent which would be far more effective per unit concentration and hence less detrimental with respect to the other physical properties-which also afiect the ultimate lubricating value of the oil.

Improved bearing metals have recently been developed which are mechanically advantageous under many operating conditions. These bearing metals include binary and ternary alloys of cadmium, silver, copper, lead, and nickel; as examples of such improved bearing metals frequently employed at the present time we may mention cadmium-silver, cadmium-silver-copper, cadmium-nickel-copper, and copper-lead alloys. However, such alloys are more subject to chemical attack than babbitt and other bearing alloys used in the past, and their use-at high temperatures, high speeds, and high pressures is some times accompanied by a deterioration of the oils employed for their lubrication, which in turn may destroy the bearings. The exact mechanism of this action is no doubt complicated and is perhaps not fully understood; it is quitepossible, that some of the metals present in the bearings tend to promote such deterioration, and that other metals present are subject to attack from the deterioration products, Whatever the cause or the mechanismthe result is that the combination of drastic lubricating conditions and alloy bearings of the general nature indicated frequently causes trouble; the bearings may be badly etched or corroded, and the quality of the oil may be rapidly deteriorated. I

It has been observed in some cases that the more highly parafiinic oils are apt to cause more as to substantially modify many of the desirable difiiculty in this respect than less parafilnic oils. It is highly desirable, therefore, to provide means whereby the oils may be so improved as to give satisfactory operating results under the conditions noted, and this is especially true insofar as concerns the more highly parafiinic oils, which should and do command a premium in price.

Moreover, it is well known that all hydrocarbon oils are more or less subject to changes through oxidation, resulting in undesirable deterioration, acid formation, and increase in carbon residue. viscosity, sludging, and the like. Such oxidative changes may become more rapid or more farreaching in extent in the presence of metals such as those employed in modern bearings, for example those of the general class mentioned above.

In order to meet these problems and to provide more satisfactory lubrication under the conditions indicated, various improvement agents have been incorporated in hydrocarbon oils prior to their sale and use. Some of these are extremely eifective but too expensive for-general use. Others, 7

while having satisfactory inhibiting or mitigating characteristics, are unsatisfactory for other reasons. A primary requisite of any such improvement agent is good oil-solubility under service and marketing conditions; moreover, since; solubilities vary in different types of oils, the

improvement agent should be capable of being added in the requisite amount to oils of difi'erent physical properties of the lubricating oil itself. The lubricating oils in which the improvement agents are incorporated have been carefully re- Y fined to meet exacting specifications, and if it is necessary to incorporate therein a relatively large amount of some agent differing in physical properties from the oil itself, the resulting composition may prove unsatisfactory for the very purposes for which the lubricating oil was prepared.

In general, it is desirable that the improvement agent should be effective at concentrations not exceeding one or two per cent by weight of the lubricating oil, although somewhat higher concentrations may occasionally be iustified for special It is, therefore, an object-of our invention to provide an improvement agent or inhibitor for addition to hydrocarbon lubricating oils, having a high degree of solubility in such oils, even the more highly refined or more highly parafilnic oils,

indicated herein, having the property of imparting substantial extreme-pressure characteristics to hydrocarbon oils when incorporated therein.

Another object of our invention comprises the 5 oils.

A further object of our invention is to provide improved lubricating compositions comprisim hydrocarbon'lubricating oils having certain im- 15 provement agents incorporated therein.

A still further object of our invention is to pro- D vide a method or methods of manufacturing improvement agents having desirable characteristics for addition to mineral oils. 2

Our invention has for further objects such additional operative advantages and improvements as may be found hereinafter to obtain.

We have found that advantageous improvement agents or inhibitors may be prepared by reacting g5 phosphorus sesquisulfide with certain anti-oxidants, said anti-oxidants comprising water-insoluble reaction products obtained by reacting phenols with olefins. Such anti-oxidant materi- 1' aisand methods of preparing the same are diso closed. in the prior co-pending application of Stevens and Gruse, Serial No. 702,258, filed December 13, 1933, Pat. No. 2,061,111, Nov. 17, 1936, and the copending applications of Troy Lee Cantrell, Serial No. 64,413 filed February 1'7, 1938, and Serial No. 99,488, filed September 4, 1936, to which reference may be made for; fur-, ther details. The disclosures of thecopending applications referred to hereinabove constitute in effect a part of the disclosure of the present 40 application, in so far as relates to the preparation of anti-oxidant materials, which are used as. starting materials in preparing phosphorus-containing and sulfur-containing improvement agents in accordance with our present invention.

Referring, for .exampleto'the aforesaid app cation of Troy lice Cantrell, Serial No. 9am,

there is disclosed-a processof manufacturing anti-oxidants wherein a phenol, is mixed with i from 1 .to 10 percent sulfuric acid havinga strength of from 00 to 100 per cent, or even fumingsulfuricacid,andsnolefinoramixture of olefins is passed, preferably in the vaporous or gaseous phase, through the'liquld mixture until the phenol undergoing reaction has gained in.

weight. from 100 mm per cent or thereabouts.

followed by washing the products so obtained with 'water'and soda solution, the con-i centration of which does not exceed 15 per cent.

Various phenols may be employed; for example, so

phenol -(CsHsOH). itself, the three cresols (C ne-CHE) and certain xylenols (CsHa(CHs)s-OH), or crude cresylic acid may be employed. The phenolic starting material should be as free as possible from pyridine bases; such pyridine bases maybe removed by conventional methods such as washing with acid or by distillation.

As olefinic materialthere may be employed individual olefins themselves, mixtures of olefins or mixtures of olefinic and non-olefinic materials. 5

By wayof example, the olefinic material may be butylenes, 'amylenes, refinery gases contain- 15 amass ing normally gaseous olefins (ethylene, propylene, butylene) in varying amount, and cracked distillates or other relatively low-boiling hydro carbon mixtures containing normally liquid oleflns, and in some instances also containing substantial amounts of dissolved normally gaseous oleilns.

Where the reaction is conducted .with the olefin in the gaseous phase, the product is relatively highly concentrated with respect to effective anti-oxidant material and may not require distillation or concentration for the purpose of isolating the latter. On the o'ther'hand, when the reaction is conducted'with the olefini'c material in liquid phase, and especially where the concentration of olefin in the starting material is comparatively low, the anti-oxidant phenol-olefin reaction product may be relatively dilute, comprising, for example, a solution of such antioxidant in gasoline-like polymers or unreact'ed liquid hydrocarbons. In such case, the antioxidant material may be, and'preferably is, concentrated by distillation or otherwise as set forth in the above mentioned co-pen'dlng applications, prior to treatment with phosphorus sesqulsul-iide as described herein. a

The exact chemical and structural nature of the anti-oxidant material as thus prepared and employed as a starting material in the manufacture of our improved addition agents is largely obscure. Although we have been able to identify certain types of compounds in these anti-oxidant materials, it will be realized that especially since mixtures of various phenols and mixtures of various olefins are frequently employed in the manufacture of these anti-oxidants, the number of possible chemical compounds is large and varied. In general, they differ from the simple alkylated phenols in that they are insoluble in dilute cans-,- tic soda solution and in that they are good antioxidants and gum-inhibitors, whereas simple alkylated phenols are not. In general, also, the alkylations, in such instances as they occur, are of secondary and tertiary types; the methods set forth in the above co-pending applications do not produce normal or primary alkylation linkages. Alkylated phenols with normal or primary linkages are undesirable (except as regards cre-;

sols and the like, used as phenolic raw niaterial for the preparation of the anti-oxidants) due to the fact that both such materials and their products of reaction with phosphorus sesquisulfide tend to be'relatively insoluble in high gravity lubricating oils. It is possible that'certain alkylated phenols of normal or primary linkage might be satisfactory as anti-oxidant starting materials provided the chains were long enough, say chains of four carbon atoms or more, on account of the closer resemblance in structure of such compounds to-paraiflnic lubricating oil constituents. However, thisis doubtful and such compounds wouldibe expected to be of prohibitive cost.

We have identified as constituents in the various anti-oxidant materials prepared as set forth hereinbefore such compounds as follows:

ortho-isopropyl phenol Ortho-tertiai'y b'utyl phenol 2.4-ditertiary butyl phenol Ortho-isoamyl phenol Ortho-tertiary amyl phenol present. It may be remarked, however, that while some of the constituents of such antioxidants may be identified, it is diflicult or impossible to identify all of the constituents of any one anti-oxidant material of the character indicated, and it is equally impossible to say which particular compound or type of compound may be of most importance. As a matter of fact, we have not been able to isolate or identify any single constituent or to recover any fraction of the concentrated anti-ioxidants prepared in accordance with the aforesaid Cantrell application, Serial No. 99,488, which constituent or fraction has an anti-oxidant value as high as that o! the total concentrated product. Nor for the purposes of our present invention is it necessary so to do; the fact remains that anti-oxidants may be prepared in the manner set forth herein and in the aforesa d co-pending applications, and such materials comprise suitable starting materials for the manufacture of phosphorus-containing and sulfur-containing improvement agents or inhibitors in accordance with our present invention. Certain of the constituents of the anti-oxidant starting materials which are not in themselves effective as anti-oxidants are, nevertheless, capable of being converted by reaction with. phosphorus sesquisulflde to yield phosphorusand sulfur-containing materials useful as inhibitors and extreme-pressure agents.

We prefer to employ as initial starting material anti-oxidants prepared as set forth above and in the aforesaid co-pending applications and having physical properties within the following ranges:

Gravity A. P. 1 15.0 to 2.5.0 Specific gravity, 60/60' F 0.0659 to 0.9042

Our invention in its broadest aspects, however,

is not limited to the preferred initial starting material mentioned hereinabove, but contemplates the manufacture of, inhibitors of the general class described from any alkylated phenols so long as such alkylated phenols possess definite anti-oxidant properties, are insoluble in water, insoluble or only slightly soluble in dilute alkali, and are permanently soluble up to 5 percent in paratlin oils. It is a requisite of such alkylated phenols, however, insofaras the present process is concerned, that the compounds shall contain one or more secondary or tertiary carbon link.

ages, or both.

- The anti-oxidant value of thls'initial starting material'shouldbe such that'the additional 0.01 per cent by weight thereof to standard gasoline stock having an oxygen stability period (E. G. C.

method) of, say, minutes, will raise the oxygen stability to at least 240 minutes. Less potent anti-oxidants are unsuitable as starting materials. 1 The character of the final phosphorusand sulfur-containing inhibitor will, of course, 'vary with the character of the phenolic and oleflnic material employed in the manuffi t te 0f the anti-oxidant starting material, with the extent of of phosphorus and sulfur subsequently introduced. All .of these factors are veryintimately inter-related. These are the primary factors, but it will be obvious that there are numerous v secondary factors, for example the degree of purification and dccolorization of the anti-oxidant starting material.

Naturally, it is tobe expected that the viscosities, specific gravities and other p yl cal characterlstlcs of the particular phenols employed will have a corresponding efi'ect upon the product, to some extent at least.

When cresylic acid, ortho-cresol and metacresoi, and the like are used in-the manufacture carrying the absorption of olefin farther. is to make the anti-oxidant product less capableof absorbing the desired amount of phosphorus and sulfur.

When the anti-oxidant starting material is prepared from phenol '(CsHsOH) itself, e. g., 90% pheno the degree of absorption of olefin may be carried farther, for example to about two mols of olefin per moi of phenol (based on the assumption that the olefin is made up entirely of C4 hydrocarbons).

The preferred olefins are those containin three to eight carbon atoms per molecule; the higher the molecular weight of the olefin the moreviscousthefinalphosphonlsandsulfur containing product will be. Olefins containing more than eight carbon atoms per molecule tend to reduce the phosphorus and sulfur contents of the final inhibitor product. Ethylene (CaHs) on the other hand, is insufilclently reactive, requiring the use of fuming sulfuric acid and does not sumcontaining from three to five carbon atoms per molecule, especially butylene; fractions obtained from gases produced in the pyrolysis of hydrocarbon oils and rich in olefins of this approximate range represent advantageous and available raw materials.

After the reaction between the phenol and olefinhasbeencarriedtothedesired rim of completion, the product is washed with. water and dilute caustic soda in the manner set forth hereinabove and in the aforesaid co-pending applications. The resultant water-insoluble anti-oxidant material is then preferably dried. The drying may be accomplished by filtering this material through adsorbent clay or :thelike, the effect of which is to dehydrate and decolorise. Or, the drying may be accomplished by heating the antioxidant material to about 400 l". in suitable apparatus; this procedure dehydrates and tends todarken 'the anti-oxidant material.

The dry. anti-oxidant may then be treated directly with phosphorus sesquisulfide, or it may first be distilled to separate undersirable lowboiling and high-boiling constituents, rsp'ective- 'iy.' Thus we may distill under a vacuum. of from ll in. to 28 in. 88., to recover a fraction distilling over between 400 and 550 I"., which fraction may then be treated with phosphorus sesquisulfide. The lower boiling material, and some from o 9,109,004 absorption of the olefin, and with the amount times also the residue, may be recycled for further reaction with the olefins in the presence of sulfuric acid. or used as an anti-oxidant.

As aforesaid, we prepared our improvement agents by reacting anti-oxidants of the general character described above with phosphorus A sesqulsulfide. The reaction is conducted by mixing phosphorus sesquisulfide with the anti-oxidant material in the desired amount and heating the mixture until volatile sulfur compounds are no longer evolved. We find it is ordinarily desirable to heat the mixture to'from 450' to 550' 1"., and

v to maintain it at that for several hours, for this purpose.

' 'We have found that, using concentrated antioxidantstarting material, prepared as set forth in the aforesaid co-pending application of Troy LeeCantreil, Serial No. 99,488, filed Sept. 4, 1036, relatively small amounts of phosphorus sesquisulfide are required, for example not more than 10 per cent by weight; in most cases the anti-oxidant material will not absorb more than a few per cent of phosphorus sesquisulfide. The products ordinarily .contain .up to 3 per cent by weight of the combined phosphorus and sulfur, the phosphorus and sulfur being present in substantially 2:1 proportion. It is not necessary to fully saturate the anti-oxidant material with the reagent in order to obtain useful products; highly desirable materials may be prepared by limiting the amount of phosphorus sesquisulfide to a'point short of completion of reaction of thephosphorus sesquisulfide with all of the anti-oxidant present,

as shown in Example 2 hereinbelow. when this extreme-pressure properties and corrosion inhibiting value, retains to a considerable extent the anti-oxidant value of the original starting material. It may be remarked, however, that even where all of the anti-oxidant is fully reacted with phosphorus sesquisulfide, the product will still possess excellent anti-oxident properties.

It will be readily understood that thereare no absolute fixed lower limits with respect the percentages of phosphorus and sulfur in the final compound. Products containing less than about 0.5 percent of phosphorus and 0.25 per cent'of sulfur are, however, apt to be insufilciently ef- I fective for general application.

The product obtained as indicated herelnabove may be used directly as an inhibitor for addition to hydrocarbon oils,in amounts which will ordinarily range from 0.25 to 2.0 percent by weight being suitable for the latter purpose.

The following examples will serve to illustrate our invention in some of its more specific embgdiments:

Exams: 1

(a) Preplration o! ans-meant mm material 20 gal. of 990% phenol" were mixed with 5 per cent of 94.5% sulfuric acid (c. p.). Olefin ga's, composed primarily of C4 hydrocarbons, was then introduced in close contact with the phenolacid mixture until the volume of the reaction Filtration escapes mixture increased to about 45 gal. This product was then washed with 10 gal. of 10 per" cent caustic soda, and later' with 10 gal. of water. After washing. the recovered product, mounting to about 40 881.. was distilled under a vacuum of 11 to 12 in. H8. The distillate was then cut into three fractions. That fraction distilling over at vapor temperature between 300 and 550 F. had the following properties:

Gravity; A. P. I. 17.9 viscosity. 8. U. V.-

100 F. seconds 212 210 F do--- 37.0 Pour poi F Color N P. A.-- 2

(0) Preparation of final inhibitor Gravity ..A. P. I 12.1

Viscosity, S. U. V. at 210 F seconds 38.5

Color P. A 2.0

Phosphorus ..percent by wt 1.52

Sulfur do 0.!

EXAMPLE 2 In this example, a distillate prepared as set forth in Example 1 (a) above was employed, except that in this instance the distillate had the following properties:-

Gravity A. P. I. 16.8 Viscosity, S. U. V. at 100 F seconds 185 Color, Saybnlr.

97 parts by weight of this distillate were treated with 3 parts by weight of phosphorus sesquisulfide, the procedure being the same as that described in connection with Example 1 (b). The resulting product had the following properties:-

Gravity A. P. I..- 12.5 Viscosity. S. U. V. at 210F seconds 36.9 Color N. P. A" 1.0 Phosphorus percent by wt..- 1.1

Sulfur These inhibitors, when added to hydrocarbon oil in amounts corresponding to from 0.25 to 2.0 per cent by weight of the oil, strongly inhibit corrosion of metal alloy bearings, such as those of silver, cadmium, copper and nickel, under conditions' where highly parafiinic oil alone would cause such corrosion. They are extremely efiective as regards contributing extreme-pressure properties and do not tend to deposit out of lubricating oil compositions containing them, at least until such time as they are required at the point of application. They are permanently soluble in hydrocarbon-oils of high viscosity. Moreover, these inhibitors have excellent anti-oxidant properties and they are substantially free from any tendency to hydrolyze. They are especially useful as improvement agents for addition to turbine oils, spindle oils, and other lubricating oils intended to be used for the lubricationof high-speed machinery.

The following tables will serve to illustrate the ride.

efiectiveness of our inhibitors and the value of lubricating compositions containing them.

' TABLE I Oil containing Untreated our inhibitor oil (prepared as in Example 1) Make-up percent by weight:

Lubricating oil--- 100 9a Inhibitor 0 1 General properties:

gravity, A. 1.66 766 32. 4 32. 2 geclilc grav y, 0.8033 0.8044 L ./gal., 00 F 7. l88 7. 198 Viscosity, S. U. V. seconds- 100 F 182.6 178. 7 01 45.9 45.7 Viscosity index 103 105 -G constant 0.805 0. 807 Flash, 0C 410 405 c, 0CF. 475 430 Pour Point, F 0 0 Color, N. P A- 1.50 1.50 Sulfur percent 0.05 0. 09 lhogphorusapercenL .1: Nil 0. 01 at on resi ue, percen 0.03 0.05 Almen test:

Lever load, p unds 10 22 Journal speed, R P M 600 000 Rubbing speed, it Imin. 40 40 Unit load, lb./sq. in 5000 11000 Lubricant temperature, F

Initial 88 88 Final 106 130 Special oxidation and corrosion test:

Time oxidized, hours 48 48 Oil bath tem erature, F 347 347 Air rate, on 10 centimeters per hour 2000 2000 guant ty oi oi], cubic centimeters. 300 300 adniium-silver bearing- Weight before test, g 35. 8070 35. 9161 35. 5260 35. 9143 0. 3410 0. 0018 Etched Good TABLE 11 Oil containing Untreated our inhibitor oil (prepared as in Example 2) Make-up, percent by weight:

Lubricating oil 100 99 Inhibitor 1 General properties:

Gravity, A. P. I 32. 2 Sgeciflc gravity: 60l60 F 0.8644 L ./gal., 60 F 7.198 Viscosity S. U. V., seconds- 100 F 17a. 2 210 F 40 Viscosity inde -G constant 0. Flash, 0C Fire, OC--F Pour point, F. Color, N. P. A.. Sulfur, percent Phosphorus, percent. Carbon residue, percent Almen test:

Lever load, pounds J ournai speed. R. P. M- Rubbing speed, it./mm Torque, lb./it Unit load, lb./sq. in Lubricant temperature, F Initial F 11181 Special oxidation and corrosion test:

Time oxidized, hours 1] bath temperatures, F 347 Air rate, cubic centimeters per hour 2000 guantity of oil, cubic centimeter-. 300

0. 3410 +0. 0019 Etched Good The lubricating oil referred to in the tests listed in Tables I and II was S. A; E. 10 grade oil which had been previously treatedwith aluminum chlo- The Special Oxidation and Corrosion Test" referred to in the foregoing tables is conducted as follows: Analloy bearing shell of certain commonly used standard dimensions is submerged in 300cc.ofthe oil oroilcompositionina400 cc.-

Pyrex beaker and heated in a thermostatically controlled oil bath to 175 C. (347 F.), and air, at the rate of 2000 cc. per hour, is bubbled through the oil in contact with the bearing shell. At the end of 48 the loss of weight and the condition of the bearing shell are determined, the bearing shell being washed free of oil and dried before weighing. when determining the effectiveness of various improvement agents, the usual procedure is to run a blank" test simultaneously with the oil composition being tested, employing for that purpose a sample of the untreated oil. In this test it is advantageous to employ commercial bearing shells.v These shells comprise a suitable metal backing faced with the alloy bearing metal. In this way, the actual bearing face is subjected to severe deteriorative conditions. By comparison of the results of such tests with actual service tests, we have found them to be in substantial agreement as to the suitability of particular lubricants.

In the tests given in Tables I and II, we employed so-called "cadmium-silver bearings of the following approximate composition:

- Metal Percent In these tests the loss in weight, while not extremely high when expressed as per cent loss",

v the reaction mixture with solidadsorb-.

is, nevertheless, very significant as the bearing shells used have an alloy facing of only-0.008 to 0.012 in. thickness on a highly resistant backing and the observed losses in the reported tests often,

represent a loss of the order of 10 per cent of the alloy facing. v

Various modificaticms in the operating pro-.- cedures mentioned hereinabove will suggest themselves to those skilled in'the art. For example, we have described washing the phenol-olefin reaction product with water and dilute caustic soda solution to effect neutralization and re-" alcohol, contact with solid alkalis such as calcium or sodium carbonates, or by con- :Esfiachas-fullers earth, activated carbon, or I expression highly paramnic oil isjemployed herein and in the claims hereinmade, it is in general intended to indicate ollsoonforming in physical properties ;to from Pennsylvania crudes; theseporainnic oils are either olls'derlved crudes or oils which have or blehdedto approach or even "exformeroilsinpara'flnioity. Where varicos to as being soluble in is intended to into'suchoilsinamotmtsup'to 10percent, withanyhasiness nor'cloudinessin the appearanceoftheresultant compositions, atleast under atmospheric temperatures and under the ordinary conditions to which such oil compositions are subjected in storage and handling prior to their actual use as lubricant.

While we have described our invention hereinabove with reference to various preferred forms and embodiments, and with reference to various specific examples, it will be understood that our invention is not limited to the details of such fllustrative embodiments or examples but may be variously practiced and embodied withinv the scope of the claims hereinafter made. Moreover, while we have in certain instances specifically given certain preferred ranges and proportions, it will be understood that our invention is not limited thereto and that such preferred ranges and proportions are in general selected for particular products and particular purposes; variations in proportions and in the methods of preparation result in products of diflerent characteristics, such products having individual ad- I vantages and utilities.

What we claim is:

1. The method of preparing an oil-soluble organic compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting an-olefin and a phenol in the presence of a catalyst and treating at least a portion of the resultant product with phosphorus sesquisulphide.

' 2. The method of preparing an oil-soluble organic compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting an olefin and a phenol in the presence of a catalyst, and treating at least a portion of the resultant product with phosphorus sesquisulphide to obtain a final inhibitor product containing from 0.5 to 2.0 per cent by weight of phosphorus.

3; The method of preparing an oil-soluble organic compound suitable as 'an improvement agent for hydrocarbon oils, which comprises reacting an olefin and a phenol in the presence of a catalyst and treating at least a portion of the resultant product, with phosphorus sesquisulfrom 0.25 to 1.0 per cent of sulphur.

4. The method of preparing an oil-soluble organic compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting phosphorus sesquisulphide with a waterinsoluble reaction product of a phenol and an olefin, saidv product having anti-oxidant properties when added to a hyrdocarbon oil.

5. The method of preparing an oil-soluble organic compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting phosphorus sesquisulphide with a waterlnsoluble reaction. product of a phenol and an olefin, said product having-anti-oxidant prop erties when added to a hydrocarbon oil, the reacting being carried to such an extent'as to incorporate suillcient-phosphorus and sulphur into the final product to give the final product the property of inhibiting the corrosion of bearing.

metals by hydrocarbon oil, when added to such '01], while retaining'to such a substantial extent the anti-oxidant value of the aforesaid phenololefin reaction product.

6. The method of Pr paring an agent for hydrocarbon oils, which comprises reacting an olefin and phenol in the presence of sulphuric acid, neutralising the resultant product, distilling the neutralized product to recover a hide, toobtain afinal inhibitor product contain- 1 oilsoluble organic compound suitable as an improvement fractionofintermediateboilingrangaandreamass-2.

acting said fraction with phosphorus sesquisulphide.

7. An improvement agent for hydrocarbon lubricam; oils, comprising a phosphorus-sesquisulphide reaction product of a water-insoluble secondary or tertiary alkylated phenol.

8. An improvement agent for hydrocarbon lubricant oils, comprising a phosphorus-sequisulphide reaction product of a water-insoluble secondary or tertiary alkylated phenol, said product containing a total of from 0.75 to 3 per cent of combined sulphur and phosphorus.

TROY LEE CANTRELL. JAMES OTHO TURNER.