US2204661A - Lubricating oil - Google Patents

Description

Patented June 18, 1940 UNITED STATES PATENT OFFICE- nunn carmo' on.

Robert Charles Cantelo, Hammond, Ind, assignor to Sinclair Refining Company, New York, I N. Y, a corporation o! Maine No Drawing. Application January 24, 1088,

I Serial No. 186,582

4 Claims.

. the physical characteristics and lubricatin properties of the oils. The invention includes a novel addition agent having the eflect 01' improving the physical characteristics and lubricating properties of petroleum hydrocarbon oils and also includes an improved compounded petroleum hydrocarbon oil containing the novel addition agent of the invention.

Oi the numerous prerequisites for a petroleum lubricating, oil satisfactory for use in internal combustion engines, three are of major importance. The oil must be stable duringstorage, handling and use so that deterioration. of the physical properties of the oil, particularly during useywill not occur. Secondly the oil should be substantially non-corrosive toward the bearings used in internal combustion engines so that the wear and loss or weight of these bearings is reduced to a minimum. Furthermore, the oil pronounced and results in serious changes in the composition and characteristics of the oil when the oil is used for lubricating internal combustion engines such as are employed in modern automobiles and aeroplanes where the oil is in contact with rapidly moving and highly heated engine parts. Such deterioration of lubricating oils is characterized, in oneaspect, by the formation of heavy sludge which tends to collect in' the oil pump and oil lines of the engine and eventually to clog them to such an exf tent as to prevent or greatlyimpair the eflicient lubrication of the engine. This deterioration the modern internal combustion engines.

lubricating oil thereby subjecting the engine to a correspondingly increased load.

The corrosive characteristics of these lubricating oils are of particular importance in view of the present'trend toward the substitution of .bearing metals such as cadmium-silver and copperbronze alloys for the previously used babbitt metal. Babbitt bearings-are generally highly resistant to corrosion; the new types of bearing al- IOYS are more susceptible to CON-081011.. Any 001- rosive action of lubricating oils increases marked- 1y with increasing temperatures and, consequently, presents a very serious problem where, as in modern internal combustion engines, the lubricating oil temperatures frequently are as milligram of a babbitt bearing in 24 hours, under 2Q similar operating conditions effected a lossof' 2012 milligrams of a cadmium-silver bearing substituted for that babbitt bearing in the same period.

high as 200-350 F. during normal operation.

The film strength of these lubricating oils is 26 of particular importance in view of the high pressures encountered between moving parts of -A high film strength insures the complete protection of moving parts by insuring the presence 0! a film of the lubricating 011 between these moving parts. A breakdown of such a film due 1 to inferior film strength results in the scoring and undue wearof adjacent moving parts.

Special methods have been devised for measuring the above-mentioned prerequisites of lubricating oils under various conditions. v

A generally satisfactory method of measuring the stability of lubricating oils in terms of the rate oi sludgeformation has been described in the Society of Automotive Engineers Journal,

vol. 34, No.5, page l72. According to this method'the time is determined in which 10 milligrams of sludge are formed in 10' grams of the oil maintained ata definite temperature while air is bubbled through the oil at a specified rate. This time, expressed in hours, is designated sludging time and-is a measure'of the rate of m further causes an-increase in the'viscosity oi the sludge-formation in that particular oil under 59 the particular conditions of the test. The term sludging time as used hereinafter refers to the above-determined measure of the rate of sludgeformation and is a relative measure of the stability of lubricating oils under conditions of storage or use.

A generally satisfactory method for determining the corrosive action of lubricating oils may be carried out with the Sinclair bearing corrosion test machine. In determining the corrosive properties of lubricating oils referred to herein I have used this test machine. This test machine comprises a test chamber the cover portion of which comprises a lead alloy bath which may be heated by electrical resistance units. A shaft extends through the interior of in the test chamber on one side wall thereof above the level of oil within the chamber, and each test bearing is attached to the removable bar at a point opposite each set of cross arms mounted on the shaft. As the shaft is rotated a stream of the test oil is directed by each of the cross arms against each of the test-bearings. Means are further provided for continuously passing air through the test chamber. In addition to the temperature regulation provided by the lead alloy bath in the cover portion of the test chamber, the chamber is partially submerged in a heated oil bath and the temperature of the test oil thus controlled.

The corrosion test is divided into two stages. In the first stage the test is conducted on a set of weighed bearings for a period of twelve hours.

The test oil is maintained at 350 F., the lead althese bearings are weighed, and the loss in weight of each bearing in each stage is reported in milligrams. A loss of bearing metal through corrosion, as determined by the above test, substantially in excess of 100 milligrams in either stage of the test indicates that the particular lubricating oil is excessively corrosive with respect to bearings of the type tested. Although it is desirable to reduce the corrosive action .of the oil to a minimum it is usually suflicient for practical purposes that such action be so reduced as to effect a loss of not substantially greater than 100 milligrams in either stage of the test.

A representative comparison of the film strength of different samples of lubricating oil may be obtained by the use of the Faville-Le- Valley test machine. This test machine measures the point, expressed in poundspressure applied in the machine, at which a film of lubricating oil breaks down between two metal parts, one part moving with respect to the other. Although this machine does not necessarily determine. the actual film strength of a particular sample of lubricating oil, it has been found to offer a useful means of comparing the relative film strength of different samples of lubricating oils.

I have discovered that the physical characteristics and lubricating properties of petroleum lubricating oils may be greatly improved by incorporating in such oils a small proportion of heptadecyl phenyl thioketone (CI'IH35) CS- (CeHa) The incorporation in a lubricating oil of a small proportion of heptadecyl phenyl thioketone, hereinafter referred to as the addition agent, improves the stability of the oil as shown by an increase in the sludging time, decreases the corrosive effect of the oil on internal combustion engine bearings and the like, and also increases the film strength of the oil as indicated by an increase in the breakdown point of the oil. I have foundthat, in general, these improvements in the general characteristics and lubricating properties of the oil are realized by the incorporation in the oils of between 0.1% and 3.0% of the addition agent by weight on the oil.

The heptadecyl phenyl thioketone used in accordance with my invention may be prepared, for example, by first producing heptadecyl phenyl ketone dichloride from heptadecyl phenyl ketone. and subsequently reacting the heptadecyl phenyl ketone dichloride with sodium hydrosulphide.

In preparing the heptadecyl phenyl thioketone referred to further herein in examples of my invention, 150 parts (by weight) of stearyl chloride (CnHasCOCl), 33 parts of benzene and about 250 parts of carbon bisulphide were placed in a reaction vessel fitted with a reflux condenser. After the mixture was cooled by means of an ice bath surrounding the reaction vessel, 65 parts of anhydrous aluminum chloride were added to the reaction mixture. Hydrogen chloride was produced during the reaction and after the rate of evolution of hydrogen chloride had diminished the ice bath was removed from around the reaction vessel. The reaction mixture was allowed to warm up to room temperature with a further evolution of hydrogen chloride. The mix- I ture was then heated to a reflux temperature and gentle refluxing was continued for a period of several hours. The reaction mixture was subsequently cooled and poured into about 500 parts of a mixture of ice and water after which about 240 parts of 38% hydrochloric acid were added to decompose the sludge-like material in the reaction mixture. The acid solution was then drawn off and an additional 625 parts of carbon bisulphide was added to the remaining solution of heptadecyl phenyl ketone. After successive washings with water, the carbon bisulphide was removed from this solution by distillation and the residue comprised about 140 parts of heptadecyl phenyl ketone.

In converting this ketone to the corresponding thioketone, 58 parts of the heptadecyl phenyl ketone and parts of phosphorus pentachloride were heated at 300 F. for a period of two hours. The phosphorus oxychloride thus formedwas removed from the mixture by vacuum distillation.

for providing an inert atmosphere within the re- 76 action vessel. An alcoholic solution oi sodium hydrosulphide was then prepared by dissolving 6.3 parts of metallic sodium in about 160 parts of absolute alcohol and by then saturating this solution with hydrogensulphide gas. This solution of sodium hydrosulphide was then added slowly to the heptadecyl phenyl ketone dichloride while stirring the reaction mixture vigorously and while passing carbon dioxide through the reaction vessel to maintain an inert atmosphere. A low temperature was maintained within the reaction mixture by means of an ice bath surrounding the reaction vessel. After all of. the sodium hydrosulphide solution had been added, the mixture was allowed to stand for a period of about one hour at the end of which period water was added to the mixture. Heptadecyl phenyl thioketone was extracted from this mixture by means of benzene whereupon the benzene solution was dried over anhydrous calcium chloride, the solution decanted, and the benzene removed from the extract by distillation. 54.9 parts were left as a residue in the distillation operation, and this residue comprises the heptadecyl phenyl thioketone which I use in the practice of my invention. An analysis of the sulphur content of this residue indicated that the compound contained about 3.82% sulphur. Inasmuch as heptadecyl phenyl thioketone theoretically contains 8.8% sulphur, it appears that the product which I use in accordance with my invention and which is referred to herein as heptadecyl phenyl thioketone comprises about 43% heptadecyl phenyl thioketone and the remainder unconverted heptadecyl phenyl ketone. This mixture can not easily; be separated by fractional distillation or the li e. stantially pure heptadecyl phenyl thioketone alone may be used with advantage or this pure compound may be blended with heptadecyl phenyl ketone to produce a satisfactory addition agent. I have found, however, that the mixture of heptadecyl thioketone and heptadecyl phenyl ketone prepared as described above may be used with particular advantage in the practice of my invention.

A more complete understanding of my invention may be had upon consideration of the following examples which have been reproduced in tabular form. It must be understood that these examples should in no way be construed as a limitation of the scope of my invention inasmuch as these examples are given merely to illustrate the improved results obtained by incorporating in lubricating oils a. small proportion of heptadecyl phenyl thioketone. I

The examples referred to above are summarized in Table I. There is shown in this table the efiect of 1.0% by weight of the addition agent upon the stability, corrosiveness, and the film strength of a Pennsylvania motor oil. This oil, before the incorporation therein of the addition agent, had a gravity of 28.2" API, a viscosity of 448 seconds Saybolt at F., a viscosity of 62.0 seconds Saybolt at 210 F., a viscosity index of 103.5, and a pour point of -5 F. The stability of the uncompounded oil and of the blended oil is indicated by the sludging time expressed in hours. The corrosiveness of the samples is shown by the loss of weight, expressed in of copper-lead and cadmium-silver bearings of an internal combustion engine. The film strength of the oil samples is indicated by the breakdown point, expressed in pounds. of these samples as It should be noted, however, that subdetermined by the Fa'ville-LeVally test machine.

Table I Percent addition agent 0 1. 0

Sludging time, hours A, 60 72 Bearing corrosion; lst stage C'u-Pb loss, mgr 637 '55 Cd-Ag loss, mgr 1561 45 2nd stage- Cu-Pb loss, mgr i084 Cd-Ag loss, mgr i237 3i Breakdown, pounds. 750 2250 The results of Table I show that the stability and film strength of this particular Pennsylvania motor oil may be substantially increased and the corrosiveness of the oil may be markedly reduced by the incorporation therein of 1.0% by weight heptadecyl phenyl thioketone. time, that is. the time required for the formation of 10 milligrams of sludge per 10 grams of oil, is increased from 60 hours for the blank oil to 72 hours for the blended oil. The corrosive action of the blank oil is shown to be substantially eliminated by the incorporation therein of 1.0% by weight of the addition agent. The breakdown point, which is a measure of the film strength of the oil, is increased from 750 lbs. for the blank oil to 2250 lbs. for the blended oil containing 1.0% by weight of the addition agent.

It will be seen from the foregoing examples that salient improvements may be made in the physical characteristics and lubricating properties of petroleum lubricating oils by the incorporation therein of a small proportion of heptadecyl phenyl thioketone. The stability of the oils may thus be increased, the corrosive nature of the oils diminished and the film strength of these lubricants markedly improved. Although the heptadecyl phenyl thioketone has been illustrated herein with respect to its eilecton a particular Pennsylvania motor oil, it should be noted that this addition agent may be used with advantage with other lubricating oils when it is desired to increase the stability, decrease the corrosive nature, or increase the film strength of these other oils, or eifect a combination of these results. Thus, for example, when the addition agent of my invention is incorporated in a substantially noncorrosive lubricating oil the stability and film strength of the oil will be improved although no noticeable improvement may be observed in the foregoing illustrations may be used advantageously with other oils. As little as 0.1% by weight of the addition agent may be sufiicient in many instances to produce the desired effect. The optimum proportion of the addition agent which may be used in each particular instance may be readily ascertained by the simple tests hereinbefore described, this optimum proportion depending not only upon the characteristics of the oils but also upon the property or properties of the oil which it is desired to improve.

Although the use of the addition agent of my invention has been described above as the only substance incorporated in the oil, it should be noted that this addition agent may be used with advantage in compounded petroleum oils containing other addition agents in which case the addition agent or my invention may supplement The sludging or enhance the effect of the other addition agents 'in the compounded oils. The addition agent of my invention may be used furthermore to correct or to overcome some deleterious eflect upon a lubricating oil caused by the presence of another addition agent incorporated in the oil for another purpose.

I claim:

1. An improved lubricating oil which comprises a petroleum lubricating oil containing a. small proportion of heptadecyl phenyl thioketone.

2. An improved lubricating oil which comprises a petroleum lubricating oil containing between about 0.5% and 1.0% by weight of heptadecyl phenyl thioketone.

3. An improved lubricating oil which comprises a petroleum lubricating 011 containing a small proportion of a mixture of heptadecyl phenyl thioketone and heptadecyl phenyl ketone.

4. An improved lubricating oil which comprises a petroleum lubricating oil containing between about 0.5% and 1.0% by weight of a mixture of about 43% heptadecyl phenyl thloketone and 10' about 57% heptadecyl phenyl ketone.

ROBERT cmmms clwmno.

' CERTIFICATE OF CORRECTION.

Patent No.'2,20h,661. June 1 8, 1914.0.

' ROBERT CHARLES CANI'ELO.

It is hereby certified that error appears inthe printed apecifioationv of the above mmbered. patent requiring correction as follows: Page 5 first column, line l|.5, before-"thioketozie" insert --pheny1--;ant1 that the said Letters Patentshould be read with this oorrection therein that the same may conform to the record. of the case in the Potent Office.

Signed 'endfsealed this. 50th day oi July, A. D. 1914.0

Henry Arsdale (Sea1) Acting Commissioner of Patents.