US1904065A - Lubricating oil - Google Patents

Description

No Drawing.

Patented Apr. 18, 1933 UNITED STATES PATENT OFFICE,

KENNETH G. MACKENZIE, OF WESTPORT, CONNECTICUT, ASSIGNOR TO THE TEXAS COMPANY, OF NEW YORK, N. Y., A. CORPORATIQN DELAWARE LUBRICATING- OIL This invention relates to lubricating oils and more particularly to lubricatmg 0118 which are compounded, having hydrocarbon oils or derivatives thereof as a base.

-mark'ed degree the power consumption costs by reducing the frictional resistance to: be

' overcome upon starting the motore or journal and during the operation thereof.

These low viscosity oils must, however,

have certain properties or characteristics to adapt them to the service for which they" are intended. The viscosities of the oils should be as low as possible, consistent with flash point for theconditions under which they are to be used. The oils must be sufliciently adherent to remain on the surfaces of the metals under severe conditions of service, and must have sufiicient body to act as cushions between the metallic surfaces, even when the parts are at rest. more, the oils must have that property known as oiliness.

7 These properties have been secured in high degree by compounding an oil or other liquid of the lowest possible viscosity with another substance having high adhesive or adherent properties, such as lard oil, in the proportion of 10% lard oil to 90%of the low viscosity oil or other liquid. It has also been suggested that palm or castor oil, metallic soaps, and oils-treated with sulphur or oxygen might in certain cases be utilized.

I have found that a highly desirable prod uct of extremely low viscosity, which has the properties of adhesiveness and extreme oiliness, can be made by compounding with the low viscosity base product, a relatively such as'electric railway Further- 1930. Serial No. 467,628.

small amount of another product which will supply the adhesiveness, required to insure constant adherence of the lubricant to the bearing surfaces. Because of the excellent lubricating value of the added product, less of it ordinarily need be added than of the f lard oil heretofore used in order to produce added product is 811- oils proposed by other investigators, and on this account the ultimate product can be lowered able to a larger market.

cost of the final and thus .made avail- In United States Patent N 0. 1,705,298 issued jointly to me and Raymond Haskell on March 12, 1929, we have described a lubricating oil comprising a hydrocarbon oil and oxidized parafiin wax. We found that the addition. of a small amount of oxidized p'arafiin wax to the usual hydrocarbon lubricating oil produced very beneficial effects. The oxidized paraflin wax which is used in compounding our lubricating oil, as described in Patent No. 1,705,298, is produced by blowing crude or refined wax with air at an elevated temperature. A change takes place in the chemical characteristics of the material, acidity developing not only as evidenced by the increasing acidity of the material itself, but also by the fact that some volatile acids may be condensed from the air after it has passedthrough the hot material. In addition to these,-however, certain saponifiablebodies or esters are formed, apparently from condensation of acids and alcohols producedby the oxidation. These esters'are found to differ from the saponifiable oils and fats in that they do not readily saponify when treated with aqueous alkali solution but require treatment with an alcoholic solution of alkali to efi'ect saponification.

Upon separation of the constituents of the complete pense involved in 'oxidized paraflin wax and compounding wax the material is heated while exposed to a current of air until practically complete oxidation takes place. The procedure yields a product which usually has very unsatisfactory properties rendering'it unsuitable for compounding withmineral oils due to the fact that the high oxidation products are dark colored gummy materials insoluble in hydrocarbon oil. To produce a product suitable for compounding, I depart from the ordinary method and, while carrying the re- Y action to a fairly definite point as may be evidenced by the acid value of the product, discontinue it before there is any substantial formation of the gumlike products of a more prolonged oxidation. 1 of about 40 may considered the upper limit to which the reaction may without the formation of gums, I prefer to only carry the oxidation to an acid'value of about 35 which insures the complete absence of gummy constituents. I

At the same time the quantity of unoxidized wax' or of little oxidized wax will usually be sufficiently low that the oils comounded with such oxidized wax product I will have a low pour test. On the other hand if the amount of little oxidized wax is objectionable from the standpoint of producing the particular service portion of esters.

too high a pour test for desired, this may readily be overcome by sweating the oxidized product to any desired degree to remove the compounded oils with higher melting portions thereof.

The following is a Specific example of a method which has been found suitable in the oxidation of paraffin wax ished product having a sufliciently large pro- .A charge of 50 pounds of paraifin wax is maintained at a temperature of from'295 to 300 F. in an enameled vessel while air is introduced in fine streams at the bottom of the vessel. The rate of introduction ofthe air is dependent upon the degree of distribution and contact which is obtained with the reaction materials. The oxidation is allowed to proceed for a period of about 48 hours during which time there is a lossof from 7% to 10%- in the weight of the charge due to volatilization products being carried off with the air stream.

A typical sample of material produced by While an acid valuebe safely carried to produce a fin-- this treatment has the following characteristics:

Acid number 39.8 Total saponification number 170.5 Neutral saponification number 130.7 Melting point -1 107 F. Neutral saponification number 3.28

(Acid number) Another sample of the same material was treated first with alkali to neutralize the free acid and then treated with methyl ethyl ketone in which the parafiin wax is, for practical purposes, insoluble. The following re-.

sults were obtained:

Per cent Free acid 'Material insoluble in methyl ethyl ketone (unsaponifiable material, mainly wax) Material soluble in methyl ethyl ketone (saponifiable material, mainly esters) 60.8

It will be observed from this data that the oxidized wax contains a large amount of saponifiable material and comparatively little unchanged wax.

The aforementioned method of oxidizing paraffin wax is given for the purpose of illustration only, and any other process may be used which will produce an oxidized wax containing a large amount of saponifiable material and comparatively little unchanged wax, as for example, the process described in the patent to J. R. Scanlin No. 1,668,871 dated May 8, 1928.

According to the present invention I prefer to use a lubricating oil stock derived either from petroleum or the-products of distillation of coal or shale that has the lowest possible viscosity for the conditions under whichthe machine operates; that is,"thelowest viscosity that is obtainable with the requisite flash point to withstand the temperature prevalent duringv use.

The lubricating oil stock may Iconsist of an oil having in general the characteristics o lubricant. The flash point should be above 225230 F. and the viscosity of the stock is v preferably within the range of 35 to 45 seconds (Saybolt) at 100" F. The finished product is then compounded with a small proportion of oxidized paraflin wax containing a large amount of saponifiable material and comparatively little unchanged wax. In most instances a compounded producthaving a viscosity of about 60 seconds or less at 100 F. (Saybolt) and containing from 2%5% of the wax will give results which are substantially equivalent to those obtained with an oil compounded with about 10% of lard oil, but under some circumstances as much as 15% of wax may be used, it being understood that the amount of wax may be varied as circumstances may require. Ordinarily an oil compounded with from 2%- 3% of oxidized paraflin wax and having a p viscosity of 45 seconds or even less at 100 F. (Saybolt) will be satisfactory. While I have thus specifically described my invention, various modifications thereof 1 may suggest themselves to those skilled in the art and I desire therefore to be limited only as indicated in theappended claims.

What I claim is: 1; A lubricating oil for heavy machinery consisting of at least 95% of 'a hydrocarbon oil having a viscosity considerably lower than that normally used for suchpurposes and within the range of from 37 seconds to V 6O seconds (Saybolt) at 100 F. and from 2% 2 to 5% ofoxidized paraflin wax which has been oxidized in such manner as to contain a large proportion of saponifiable material. 2. A lubricant for railway journals and bearings comprising a mixture of the hydrocarbon oil remaining after distilling off about of the lighter constituents of kerosene and having a viscosity within the range of from 37 seconds to 60 seconds Saybolt) at 100 F. and from 2% to 5% of oxidized parafiin 'wax which has been oxidized in suchmanner as'to contain a large proportion of saponifiable material. 7

3. A lubricant for railway journals and bearings consisting of from to 98% of 35 a. hydrocarbon oil having a viscosity of approximately 45 seconds (Saybolt) at 100 F. and from 5% to 2% of oxidized paraflin wax which has been oxidized in such manne'r as to contain a large proportion of saponi- 40 fiable material. v In witness whereof I have hereunto set my had this 7th day of July,-'1930.

KENNETH G. MACKENZIE.