US2120119A - Stabilized lubricating oil - Google Patents

Description

Patented June 7, 1938 PATENT OFFICE STABILIZED LUBBIOATING on.

Waldo L. Steiner, Ponca City, Okla, assignor to- Continental Oil Comp y, Ponca Oity,.0kla., a corporation of Delaware I No Drawing.

-., 12 Claims.

cause cloudiness, precipitation or other objectionable characteristics in the finished lubricant. The change may be 'due to the properties of the addition material, the properties of the oil, or a I combination of the two. In some cases. the change is evidenced immediately on blending; in

others considerable time may be required before the objectionable change is apparent. Generally, the cloudiness or precipitate disappears or goes back into homogeneous solution with the hydrocarbon oil when the lubricant is put into actual service. This reversal of action. is no doubt due in part to the influences of temperature, pressure and metal contact experienced in actual lubricating service. e

Cloudy oils are diflicult to market and may be the source of considerable sales resistance. In fact, it may be the direct cause of marketing fail-- are of 'a product which should be a market success. The cloudiness or. slight precipitate, as a rule, does not impair the lubricating qualities of the lubricant.

I have found that cloudiness usually results from the presence of free organic acids or substances which will react acid in the lubricant.

86 The degree of cloudiness i's'greatly influenced by the presence of other substances in the lubricant such as sulphur, soaps and the like.

The primary object of my invention is to stabilize lubricants and prevent the formation of 40 a cloud or precipitate.

' Another object of my invention is to accomplish this result cheaply and without in any way impairing the desirable lubricating qualities of the lubricant.

Other objects will be apparent to those skilled in the art on reading the following description of my invention.

In general, my invention comprises the addi- 50 tion of organic substances which are basic or alkaline with respect to the hydrocarbon lubricants which have a tendency 'to cloud or give a precipi tate due to their free acid content or content of acidic substances. 55 The following example is given to clarify my 'thenic acidis very difllcult.

Application January 20, 1933, Serial No. 652,698

invention but is not to be considered as a limitation to my invention.

A high fllm strength free wheeling gear lubricant can be made by the addition of a sulphur base oil and lead naphthenate to a hydrocarbon 5 mineral oil. The percentage of these constituents in the finished lubricant can be varied over wide limits depending upon a number ofli'actors and particularly on the degree of high fllm strength desired in the finished lubricant. A common 1 characteristic of all of these blends is that on standing (1 to 30 days) a substance insoluble. in the hydrocarbon oil separates, and, if not disturbed, will slowly settle to the bottom of the container. The insoluble material which sepa- 15 rates is visible and detracts from the sales value of the lubricant. This is particularly true of the bottom portion of the container wherethe precipitate has concentrated. To my knowledge this precipitate does not impair the lubricating qu'ali- 20 ties of the oil.

In my study of the insoluble material, I found that it was influenced and dependent on the free acid content of the lubricant. I could greatly inhibit the formation of the insoluble substance by 25 carefully freeing the lead n'aphthenate oi allfree naphthenic acids. This is not commercially feasible, since freeing the lead naphthenate of naphnaphthenate will release free acid again until a 30 certain equilibrium between lead naphthenate acid is reached.

The addition of organic bases to theblend tends to neutralize the 'free naphthenic acid and substantially prevents formation of insoluble material. At any rate, the formation of the insoluble substance is inhibited to a point where it is. not a cause of sales resistance. g

In practicing my' invention 1 determine by titration the approximate or exact'amount crime 40 acid present in the lubricant and sumcientorganic base is added to neutralize the determined amount of free acid-with about 5 to excess of the base. The acid content of the. various 7 constituents of the finished lubricant may be de- 45 termined in the usual manner'and the organic base added to the acidic constituents or blended with the. acidic constituents and the mineral oil in one step.

The organic base should be thoroughly incor- 5o porated in the lubricant. With viscous lubricants the blending should be done at high temperatures, say up to 200 F. or above, the temperature used depending on the consistency of the mixture and upon the organic base being used. A

Furthermore, lead all :1 Organic bases as used in the description of my invention may include such substances as the nitrogen containing organic compounds. Tri: ethanolamine has been found to be entirely satisfactory and better than many of the other organic bases. Diphenylamine may be used. Analine is not sufliciently basic to be of much value. Nearly all of the secondary and tertiary amines are satisfactory. ;Some of the substituted pri mary amines maybeused with success.

Since the amount of free acid occurring in th lubricant is usually small, the amount of organic base used is, as a rule, a very small percentage based on the lubricant volume.

ness in the general sense to indicate both the appearance of a cloud in the lubricant and the formation of the precipitate.

The sulphur base is prepared from a fatty oil and sulphur. F'atty oils as obtained commercially are not absolutely free of acid and the additionof sulphur tends to saponify part of the fatty oils to form fatty acid; so that considerable free fatty acid is usuallyfound in the sulphur base. It may be that a combination of the free fatty acid and the sulphur base with the free fatty acid from the lead'naphthenate may cause the difllculty. At any rate when an organic base is added according to my invention, the difliculty is obviated.

Having .thus described my invention, what I claim is:

1. A lubricant comprising in combination a hydrocarbon oil, an addition product of acidic nature and a small quantity of an organic base.

2. A lubricant comprising in combination a hydrocarbon oil, an addition product of acidic nature and a, small quantity of an organic base containing an amino group,

3. A lubricant comprising in combination a hydrocarbon oil, an addition product which will re-,

lease an acid and a small quantity of an organic base.

4. A lubricant comprising in combination a hydrocarbon oil, an acid releasing addition product and a secondary amine.

5. A lubricant comprising in combination a hydrocarbon oil, an acid releasing additionproduct and a tertiary amine.

6. A lubricant comprising in combination a hydrocarbon oil, an acid releasing addition product and a substituted primary amine.

7. A lubricant comprising in combination a hy-. drocarbon oil, an acid releasing addition product and a diphenylamine. 8. A lubricant comprising in combination a hydrocarbon oil, an acid releasing addition product 1 and a triethanolamine.

9. A lubricant comprising in combination ahydrocarbon oil, lead naphthenate and an organic base.

10. A lubricant comprising in combination a hydrocarbon oil, lead naphthenate and triethanolamine- 11. A non-clouding lubricafit comprising a hydrocarbon oil, lead naphthenate and a small quantity of amine.

12. A non-clouding lubricant comprising in combination a hydrocarbon oil, lead naphthenate and a small quantity of diphenylamine.

WALDO L. STEINER.