US1939994A - Lubricating oil - Google Patents

Description

Patented Dec. 19, 1933 UNITED STATES LUBRICATING OIL Bert H. Lincoln and Alfred Henriksen, Ponca City, Okla., assignors to Continental Oil Company, Ponca City, Okla", a corporation of Delaware No Drawing.

Application July 25, 1932 Serial No. 624,642

- 13 Claims.

Our invention relates to improved methods for the production of high quality lubricating oils and specifically comprises such products as new compositions of matter.

Present day mechanical devices require lubricating oils of high film strength and of high oiliness characteristics. present day hydrocarbon lubricants of the very highest quality are deficient in these two very important characteristics. These two properties are of vital importance under conditions of thin film lubrication where the lubricant has been squeezed from between the friction surfaces due to high pressures, slow speeds and other causes.

It is readily seen that the viscosity or body of the lubricant plays no part in this type of lubrication and that the remaining film of oil must have a very high film strength and be of high oiliness value to prevent rupture of the film of lubricant,

which would cause seizure, and to keep the coefficient of friction as low as possible.

Mechanical devices are being designed for higher pressure operation and the film strength of the best quality straight hydrocarbon lubricants has been found to be too low and not sufficient. Therefore, an invention which provides a means of improvingthe film strength of these lubricants is of great importance to the art of lubricant manufacture and to the designer and fabricator of mechanical devices.

Substantially all machines operate in parts or at times totally under conditions of boundary or thin film lubrication, under which conditions the oiliness or unctuosity of the lubricant is the first and primary requisite of eificient operation. Those skilled in the art of lubricant manufacture or machine manufacture will readily appreciate the value of an invention that will improve the oiliness of these otherwise highest quality lubri- 0 cants. a

In starting idle mechanical equipment which is lubricated from a sump by pumping or circulating the lubricant, there is always a short period of time in which the rubbing surfaces must operate under conditions of dry friction if ordinary hydrocarbon lubricants areused. With dry friction the wear on friction surfaces isextreme and during cold weather when the lubricant is sluggish or during periods when the lubricating system is not properly functioning for one reason or It has been found that f another, the rubbing surfaces may not only suffer considerable wear but may seize and be damaged to the point where they must be replaced. The product of our invention has the very important property of reacting with the metal surfaces, penetrating the metal, and leaving a film of lubricant with the highest possible oiliness character which remains on the metal surface irrespective of the length of time the machine has been idle.

This high oiliness film gives very even and smooth operation which may be easily discerned by the experienced operator and lubricating engineer.

When the hydrocarbon lubricants are diluted with unburned fuel or with other light hydrocarbons, the small degree of oiliness of the original hydrocarbon, lubricant is greatly decreased. We have found that the addition of the product of our invention to hydrocarbon lubricants more than compensates for the loss in oiliness by dilution.

In outline, our invention comprises the addition of relatively small amounts of the product of condensation of halogenated fatty acids to a hydrocarbon lubricant.

An example Will serve to clarify our'invention but it should not be considered as a limitation to our invention. Ordinary commercial stearic acid was chlorinated until the chlorinated product had a 13 F. cold test. The chlorinated acid was freed of excess chlorine and hydrogen chloride by heating and the use of solvents. To this product sodium ethoxide was added in an alcoholic solution. The reacting mixture was warmed and allowed to proceed to apparent completion. In this example four times the molecular quantity of sodium ethoxide was added, assuming that the halogenated acid contained 7% of chlorine. After the reaction was apparently complete the sodium was removed from the carboxyl group with an inorganic acid, the entire product freed of excess alcohol, inorganic acid, and any inorganic salt by thorough water washing. In this example the finished product was not distilled but such is contemplated in this invention.

The product of the above condensation was then added to a high quality hydrocarbon lubricant and tested for improved oiliness and improved film strength.

The Herschel friction testing machine devel- Timken Roller Bearing Company.

oped by Dr. W. H. Herschel of the U. 8. Bureau of Standards was used for determining the friction. The original hydrocarbon lubricant showed, by this test, a coefllcient of friction of 0.140 and the operation of the friction testing machine was not smooth. Adding '1% of the product of the above condensation to another sample of the same oil, and repeating the test, gave a coefficient of friction of 0.077 or a reduction in friction of about 45%.

To determine film strength we used the Timken machine developed and described by the In this machine the pressure between two friction surfaces is increased until the oil film ruptures. The original hydrocarbon oil ruptured when 18.2 pounds weights had been added, which is equivalent to about 10,500 pounds per square inch. This indicates the high quality of the original oil. To another sample of this same oil we added 1% of the prdouct of the above condensation and repeated the Timken film strength test. blended lubricant didnot break until 45.5-pound weights had been added, which is equivalent to about 26,000 pounds per square inch pressure on thefriction surfaces. In other words, the film strength was improved by approximately 247% by the addition of 1% of the products of the above condensation.

Other similar examples could be cited using different acids, different halogens, different condensing agents and varying amounts, but the above teaches the general principle and additional examples would only tend to unduly lengthen the specification. 1

Any of the commercial fatty acids, fatty oils and esters or mixtures of the commercial fatty acids and/or fatty oils and/or esters may be used, such as oleic, fatty acids from corn oil, cocoanut oil, cotton seed oil, castor oil, naphthenic acids, etc. Animal, vegetable or natural occurring oils may be used. Esters of any of the fatty acids above mentioned or any aromatic acid may be used; the esters may be any of the natural occurring products such as carnauba, spermicetta wax, etc. This invention contemplates the use of all fatty acids be they products of oil saponiflcation, natural occurring or synthetic. The impurities in the commercial product do not affect this invention; therefore, commercial acids, etc. are satisfactory.

Fattyoils and the various esters when treated by this process are converted into the fatty acid. This allows saponification and obtaining the product of this invention in one series of operations. Use of fatty oils and esters is equivalent to use of fatty acids, since any of the glycerine formed by saponification is removed by later washing and/or heating.

Any of the well known steps of halogenating fatty acids may be used. This invention does not contemplate protecting. any particular step. The saturated fatty acids may be halogenated by substitution, and the unsaturated bydirect addition and followed by substitution. The degree of halogenation is subject to variation over wide limits. Small amounts of halogen may be introduced or very large amounts, depending upon the type and-character desired in the finished product. The greater the degree of halogenation, the greater the amount of condensing agent required usually, and for some purposes the amount of condensation product to be added The to the hydrocarbon oil decreases as the degree of halogenation increases.

x Any of the well known alkaline condensing agents may be used. Alkali hydroxides, bases in organic solvents, mixed inorganic-organic condensing agents, etc. may be used. The quantity of condensing agent to be used may be determined by an analysis of the halogenated acid. The amount employed should be slightly less than the theoretical requirement in order that some halogen in an organic molecule will remain. By varying the amount of condensing agent used, products of varying halogen content may be obtained. This same result could be obtained "by increasing the degree of halogenation, but using a constant amount of condensing agent.

Any of the halogens may be used or any desired mixture of halogens. Part of the fatty acid may be chlorinated and another part brominated, and these two mixed prior to'the condensing reaction.

In the above example with sodium ethoxide as the condensing agent, it was found that a solvent for the reaction was not necessary. In other cases organic solvents should be used for the reacting mixture. These solvents should be removed after the reaction is complete. In some cases it is advisable to distill and separate the finished product into desirable and undesirable fractions. If distillation is employed, very low temperatures with a high degree of vacuum should be employed.

The alkali condensing agent reacts with the acid hydrogen of the fatty acid, forming the soap. Inorganic acids are used to hydrolyze the soap and free the acid by well known and established reactions.

I The quantity of the product of condensation to be added to the hydrocarbon lubricant depends upon the character of the hydrocarbon agent removes the halogen from, say, two halogenated acids freeing the alkalihalide and open-' ing two bonds on two molecules, which combine and form a molecule containing two or more carboxyl groups. With the inorganic-organic type condensing agent, such as sodamide, sodium methoxide, sodium ethoxide, etc., the final product may also contain halogenated acid with an OCzHs radical, or an NH: radical formed by the addition of the condensing agentradical at. the point where the halogen was removed. Therefore, it is readily seen that the product of our invention is not a pure chemical compound but a mixture of unchanged reacting components and their reaction products. We believe the free carboxyl group contributes to the high oiliness character of the finished productand that organic molecules containing halogen influences the film strength. It should be understood that we do not limit our invention to any theory but rely upon the very advantageous results obtained in use.

With the above reservation in mind, namely that our invention is not to be limited by our theory, the following reactions are given as our conception of what happens when condensation takes place. It is to be borne in mind that our invention shows a simple and economical method of high emciency for improving the film strength and holding a low coefflclent of friction.

01' Ol' OI c1 c1 01 Or, if two halogens on each acid molecule are removed, we may have a double connection in the final dibasic acid. As pointed out above, we

have not proved that the reaction occurs as shown above, nor do we know anything about 1 concentration of the reaction products when the reaction has reached equilibrium. Y

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is withinthe scope of our claims. It is further obvious that various changes may be made in details. within the scope of our' claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details sho and described. I

Having thus described our invention, what we claim is:

'1. A lubricant comprising in combination a hydrocarbon lubricant and asmall quantity of a condensation product obtained by the condensation of two halogenated fatty acids by an alkali condensing agent. I

2. A lubricant comprising in combination ahydrocarbon lubricant and a small quantity of a condensation product obtained by the condensation of two chlorinated fatty acids by an alkali condensing agent.

3. A lubricant comprising in combination a hydrocarbon lubricant and a small quantity of a condensation product obtained by the condensation of two halogenated fatty oils by an alkali condensing agent.

4. A lubricant comprising in combination a hydrocarbon lubricant and a small quantity of a condensation product obtained by the condensation of two-chlorinated fatty oils by an alkali condensing agent.

5. A lubricant comprising in combination a hydrocarbon lubricant and a small quantity of a condensation. product obtained by the condensatinon of two halogenated esters by an alkali condensing agent.

6. A lubricant comprising in combination a hydrocarbon lubricant and a small quantity of a condensation product obtained by the condensation of two chlorinated esters by an alkali condensing agent.

'7. A lubricant comprising in combination a hydrocarbon oil and a small quantity of a condensation product obtained by condensing any two materials contained in the following group: a fatty acid, a chlorinated fatty acid, a halogenated fatty acid, a fatty oil, a chlorinated fatty oil, a halogenated fatty oil, an ester, a halogenated ester, a chlorinated ester.

8. ,A lubricant comprising in combination a hydrocarbon oil and a small quantity of a condensation product obtained by condensation of a chlorinated fatty acid with a chlorinated fatty oil.

9. A lubricant comprising in combination a hydrocarbon oil and'a small quantity of a condensatiori product obtained by condensation of a chlorinated fatty acid with a chlorinated ester.

10. A lubricant comprising in combination a hydrocarbon oil and a small quantity of a condensation-product obtained by condensation of a chlorinated ester with a chlorinated fatty oil.

11. A lubricant comprising in combination a hydrocarbon oil and a small quantity of a con-' densation product obtained by condensation of a chlorinated fatty acid with a chlorinated fatty acid.

' 12. A lubricant comprising in combination a hydrocarbonoil and a small quantity of a condensation product obtained by condensation of a chlorinated fatty oil with a chlorinated fatty oil.

13. A lubricant comprising in combination-a hydrocarbon oil and a small quantity of a condensation product obtained by condensation of a chlorinated ester with a chlorinated ester.

. BERT H.1INCOLN.

ALFRED EN.