US1850561A - Lubricating oils - Google Patents

Description

Patented Mar. 22, 1932' UNITED STATES PATENT OFFICE ROBERT C. MORAN, OI WOODBURY, NEW JERSEY, ASSIGNOB TO VACUUM COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK nunnzcnrnve one No Drawing.

The present invention relates to improvements in c'ompoundedlubricating oils.

It is well known that the lubricating qualities of mineral oils may be improved by the addition of fatty acids, either alone or as constituents of vegetable or animal fats. The most commonly used fatty acids for improving the lubricating property of mineral hydrocarbon oils are oleic and stearic acids. The use of these fatty acids involves certain disadvantages. Oleic acid is liquid at ordinary temperatures and hence "does not adversely aflectthe pour test of lubricating oils when mixed therewith, but, due to its unsaturated character, oleic acid readily oxidizes so that mixtures thereof with lubricating oils are decidedly objectionable in practice because of their tendency to sludge formation and the development of corrosive acidity. Stearic acid, on the other hand, is a saturated acid and hence is free from that objection to oleic acid of imparting to its mixtures with lubricating oils the ready tendency to sludge formation and the development of particularly corrosive acidity. But stearic acid is objectionable in its effect on the pour test of lubricating oils when admixed therewith. For instance, a lubricating oil having a pour test of 5 F. showed, after the addition of 2% stearic acid, a pour test of +36 F.

The present invention resides in the dis covery that the addition, to a mineral oil, of the acid product of the interaction of oleic acid and benzene in the presence of aluminum chloride, will give to the mineral oil a lubricating quality similar to that obtained by the addition of saponifiable oils and fats to mineral oils.

The acid may be prepared in the following manner. To 200 gms. of oleic acid dis solved in 400 gms. of dry benzene are added 100 gms. (1.2 molecular" proportions) of coarsely powdered aluminum chloride. When the reaction has moderated, the mixture is gently heated (finally to 80 C.) with occasional shaking, .until hydrochloric acid is no longer evolved. The heating requires about six hours. The mixture is then poured into 600 c. c. of 20% hydrochloricacid, and

Application filed August 18, 1929. Serial No. 886,489.

the benzene removed by steam distillation. The residual brown, viscous oil may be used as such,.but preferably is fractionated under reduced pressure, the distillate being finally obtained as a yellowish oil, boiling point 5 about 250 C. at 4 m. m., and solidifyng at about 15 C; The crude or redistilled product is particularly suitable for use in improving the lubricating efiectiveness of lubricating hydrocarbon oils, as it a liquid, w

readily miscible with said lubricating oils and is essentially of a saturated character. Hence, when admixed with lubricating oils, it has no adverse efiect on the pour test such as is caused by stearic acid, nor does it impart to the mixture the tendency to sludge formation and the corrosive acidity characteristic of oleic acid.

, As an illustration of this invention, a lubricating oil having a specific gravity of 0.90

was .mixed with 3% of acid without adverse efiect on the pour test. The mixture, atomized with air at about 300 F. and the atomized stream directed upon a test piece of Admiralty metal, maintained at about room temperature, resulted in no corrosion of the metal after about ten days. Upon similar test conditions, a 3% addition of oleic acid to the same lubricating oil gave a mixture which corroded the Admiralty metal in a relatively the volume of the latter. The addition of these amounts of the acid, while greatly improving the lubricating properties of the oil, with corresponding lowering of the interfacial tension against water, has' no effect upon the original pour test of the oil. The

importance of this feature with respect to cold weather lubrication is obvious.

While there has been specified 3% of acid in the above lubricating oil mixture for illustrative purposes, lesser and greater quantities of the acid may be used with advantage in certain cases.

The acid produced by the process herein described is a phenyl-stearic acid of which the precise constitution is not known. As it was first described by Nicolet and de Milt it may be designated as Nicolet and de Milts acid. Its theoretical formula is believed to be either cfia- (CH h-CH- exam-coon CH4; (CH2) B-cH- (CHQTCOOH :13: or it may contain both of these isomers. S0

far as known, either or both of these isomers may be used with equal efiectiveness.

What I claim as my invention and desire to secure by Letters Patent is:

A lubricant consisting chiefly of mineral lubricating oil, with the addition of a relatively small amount of Nicolet and de Milts acid.

ROBERT C. MORAN.