US2325533A - Lubricant - Google Patents

Description

@m0 Y Qma omo LUBRICANT Filed Oct. '7. 1940 J. v. MoN'coMERY ETAL July 27, 1943.

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O N -uvaM INVENTOR JAMES v. MoNTGoM BY LUKE B cooDsoN M z u L ATTOY Patented July 27,

LUBRICANT James V. Montgomery. Olrmulgee, Okla., and Luke B. Goodson, Phillips, Tex.. assignors to Phillips Petroleum Company, a corporation of Delaware Application October 7, 1940, Serial No. 360,172

4 Claims. (Cl. 252-51) This invention relates to improved lubricating oils and particularly to addition agents for lubricants for improving the characteristics thereof.

It is known that certain oiliness or film strengthening agents added to lubricating oils and greases decrease wear during the starting of cold motors, lessen wear during operation by decreasing bearing temperatures, tend to prevent i ring-sticking and cylinder scoring, and reduce internal friction in some cases. Many of these addition agents, while having the above-mentioned benecial effects, have deleterious effect on the corrosiveness or stability of the lubricant and thus their use is of questionable overall value.

An object of this invention is to provide a lubricant having high oiliness properties.

Another object of this invention is to provide a method o'f increasing the oiliness of an oil or grease and at the same time reducing the corrosiveness and oxidation ltendencies of the oil.

Still other objects and advantages will be apparent to those skilled in the art from a study of the following disclosure.

We have found that aryl-alkyl amino compounds containing a hydroxyl group have' a marked effect in improving the oiliness characteristics of lubricants when added in relatively small proportions without injuring other qualities of said lubricants, but rather improving them. A very small amount of the aryl-alkyl amino hydroxyl compound when added to the oil or grease is suflicient to effect very definite improvements in the oil, for. example, it inhibits metallic corrosion and reduces oxidation within the oil.

A series of comparative tests was made on an acid and clay treated Mid-Continent straight residual mineral oilv of 60 seconds Saybolt Universal viscosity at 210 F., and on the same straight mineral oil plus additive, using a modifled Timken Bearing Wear Test Machine. This machine consists essentially of a polished steel journal rotating against a section of a commercial babbitt-lined connecting rod bearing insert. A loading arm is so connected as to provide a means of varying the pressure of the rotating journal against the section of the connecting rod bearing insert. The oil to be tested is fed to the surface of the bearing insert at a predetermined rate and temperature. A series of 15 minute runs was made, with a shaft speed of 220 R. P, M., and anvoil temperature of 130 F., each run under diiferent pressures. Z N/P (viscosity times speed divided by pressure, wherein viscosity is measured in pound-minutes per square inch, speed in R. P. M., and pressure in pounds per square inch of projected bearing area, as given in Hershey; Theory of lLubrication, published in 1938, by John Wiley 8a Sons, Inc., New York City) values were calculated for each pressure used and plotted against the correspondingwear (loss of weight in milligrams) of the bearing insert to obtain curves which illustrate transition from fluid film lubrication with attendant low wear to thin iilm lubrication with attendant high wear. A shift in this transition point toward low Z N/P values is an indication of increased oiliness.

Figure 1 is a plot of curves showing the relation of Z N/P values to bearing wear in milligrams for a straight oil and this same oil plus additive. Y

Under the conditions of the test Z (viscosity) and N (speed) are regarded as constant, and are known. 'I'he pressure P is varied, starting with relatively low pressures, and making 15 minute runs at graded increments of pressure. The wear is measured by loss in weight of the bearing insert during the 15 minute run, and the results,.that is, the loss in weight in milligrams are plotted as shown on the curve. The pressure is increased until a range is reached wherein the wear rapidly increases, with wear figures which are erratic and difficult to check. This is the transition range. As the pressure is further increased, the Wear iigures become orderly, and increase in proportion to the pressure, again giving a smooth curve at much higher wear figures than before. This portion of the curve is beyond the transition point. The transition point is normally taken as the mid-section of the transition range portion of the curve'.

wherein the break occurs.

Referring to the figure of transition point curves, the straight mineral oil curve shows a transition from fluid film to thin film lubrication at a Z N/P value of 2.3X10-8, while the same mineral oil containing 0.1% by volume of phenyl ethanol amine shows a transition point from the said fluid film to thin nlm lubrication at a Z N/P value oi' 2.05X10. As a matter of comparison, under similar laboratory conditions a sample of a commercial motor oil containing a chlorinated ester showed a.l transition point value of 2.15X and a sample oi! the above mentioned Vstraight mineral oil plus 0.25% castor oil showed a transition point value of 2.00 10.

Thus, it is evident that a mineral oil containing our additive will continue to furnish iluid iilm lubrication with attendant low wear, under conditions of higher load, lower speed, or higher temperature (which decreases the viscosity of tures. For instance. the boiling range of the commercial phenyl ethanol amine used in the above cited example was:

Degrees F.

Initial boiling point 506 5% 520 50% i -i 526 End point 534 A sample of commercial phenyl ethanol amine of the above given distillation characteristics is the ou) than the same straight mineral on without our addition agent. A lubricant containing a small quantity oi' our additive becomes a tenacious lubricant in that it more readily wets, lubricates and adheres to the metallic surface to be lubricated and is resistant toward removal therefrom.

While the lubricating properties of an oil containing 0.1% by volume of phenyl ethanol amine is illustrated ln the accompanying ilgure,

we do not wish to be limited by the use of this amount of illm strengthening additive since the use of large quantities, for example up to 0.2% by volume, as well as smaller volumes, have been found to give results comparable to those illustrated in the ligure.

The anti-oxidation and anti-corrosion effects which are exerted by our compounds are probably due to the fact that our compounds contain an amino group and therefore are basic in nature. Being basic, they tend to react with the acidic oxidation products of the oil as fast as these are formed during oxidation of the oil with favorable combination of an amino group, a hy- Y droxyl group, and an aromatic group in the same molecule. The presence of the aromatic group serves to make our compounds highly miscible with the mineral oil, and thus We avoid the use of auxiliary solvents.

Our compounds are high boiling and stable, and thus remain in the oil at elevated temperacomposed mainly of the compound phenyl ethanol amine, having the structural formula Cim-N CaHiOH and two impurities present in lesser amounts, one of which is phenyl diethanol amine, having the formula and phenyl ethyl ethanol amine, having the formula CoHs-N C,H.0H

We do not wish to be restricted by any theo- Iries as to the reasons for the beneficial results obtained by the use of our compounds in lubricating oils but only by the limitation of the iollowing claims.

We claim:

l. An improved lubricant of the class consisting o'f oils and greases having incorporated therein as a film strengthening agent phenyl ethanol amine in amount less than 0.2%.

2. Animproved lubricant of the class consisting of loils and greases having incorporated therein phenyl ethanol amine to improve the strength of the lubricant.

3. An improved lubricant of the class consisting of oils and greases having incorporated therein commercial phenyl ethanol amine to improve the illm strength vof the lubricant.

4. An improved lubricant of the class consisting of oils and greases having incorporated therein as a illm strengthening agent commercial phenyl ethanol amine in amount less than 0.2%.

JAMES V. MONTGOMERY. LUKE B. GOODSON.

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