US1727109A - Lubricating composition - Google Patents

Description

Patented Sept. 3, 1929..

UNITED STATES PATENT OFFICE.

ALBERT L. KLEES, 0]? NEW YORK, N. Y., ASSIGNOR '.I.O COMBUSTION UTILITIES COB- POBATION, OF NEW YORK, N. Y., A CORPORATION OF MAINE.

LUBRICATING No Drawing.

This invention relates to lubricating oils and particularly to a new and useful. composition which possesses properties making it of exceptional value as a lubricant.

In true oil film or viscous lubrication, there is no slipbetween the solid and liquid surfaces and movement takes lace by the intermediate planes of the liquid sliding over one another. The resistance to this shear of plane over plane is due to the viscosity of the liquid. Efficient lubrication under all conditions has been foundito depend upon the possession by the liquid of some other property which enables it further to reduce the frictional resistance, and that property has been given the name of oiliness. Mineral oils are as eflicient lubricants under many conditions as animal or vegetable oils of similar viscosity and as they are more inert chemically and are cheaper they are most widely used; There are, however, many conditions 'of operation and many parts of machinery in which a perfect oil film cannot form and in which the friction to be overcome is due in large part to contact between solid and solid. Such a condition of incomplete lubrication occurs most frequently in bearings when starting from rest and when the load is exceptionally heavy. This static friction in a bearing bears little or no relation to the viscosity of the lubricant, even when oils of the same class are used, and the character of the surfaces in contact has a great influence upon its magnitude. Mineral oils and fatty oils show a great difi'er:

ence in behavior under these conditions. At

the same pressure and temperature it has been found for example that under starting loads castor oil, which has a viscosity sev-' eral times that of a heavier engine oil, nevertheless lowers the frictional resistance to a greater degree. This reduction of friction by lubricants such as castor oil has been ascribed to oiliness, which property is possessed in greater degree by animal and vegetable oils than by ordinary mineral oils. Since different bearing metals have a widely different effect upon static frictional resistances, the theory has been advanced that oiliness is an effect produced by the lubricant upon the metallic surfaces with which it is in contact, rather than a property, of the lubricant as a liquid. It has been found that the best lubricating mineral oils contain unsaturated molecules and it is well COMPOSITION.

Application filed July 18, 1924. Serial No. 728,278.

known that vegetable oils are usuall glycer l esters of unsaturated fatty aci s. It is elieved therefore that the unsaturated molecules of the lubricant may enter into a firm physico-chemical' union with the ex posed metal, forming a bearing surface which is composed of both oil and metal.

The primary object of the present invention is to provide a'lubricating composition vide a lubricating composition the properties of which can be readily varied to meet varying conditions of viscous or oil film lubrication.

Another object of the invention is to provide a lubricating composition which can be advantageously used in admixture with petroleum roducts to improve their properties of oi iness.

With these and other objects in view the present invention consists in the new lubrieating composition hereinafter described and particularly defined in the claims.

The composition forming the subject matter of the present inventionmay be described briefly as consisting of a mixture of neutral oils, insoluble in alkali and dilute mineral acids and having a particular chemical constitution, either with or without ordinary petroleum lubricating oils and/or hydrocaron oils of high temperature tar origin and/or high boiling tar-acids and/or graphite or other unctuous material. The neutral oils are characterized by the presence in large proportions of cyclic unsaturated non-benzenoid or hydro-aromatic hydrocarbons, which are related to the benzene naphthalene series of compounds such as are found in ordinary coke-oven tar but which have a. larger content of hydrogen and usually of alkyl groups and hence have a higher molecular weight, a lower density, and a lower refractive index for the same boiling oint. These neutral tar oils difl'er further rom the above-named aromatic (benzenenaphthalene) hydrocarbons by their ability to decolorize dilute solutions of otassium permanganate or bromine. They ifii'er also from petroleum products in both their chemical and physical properties, since they are essentially primary distillates of coal or other bituminous material and are formed only when the coal is distillell under low temperature conditions of carbonization. The tar-acid group which is sometimes used in making up the above composition is composed of cyclic organic hydroxy compounds, soluble in alkali, of which at least boil above 220 C. These compounds resemble the higher phenolic homologues which occur in very small quantities in ordinary cokeoven tar, but differ from them by virtue of a larger content of hydrogen and of alkyl groups which give them a higher molecular Weight, a lower density and a lower refractive index for the same boiling point.

The component groups which make up the present composition each have distinct functions to perform and their relative proportion in the final mixtures may be varied at will to suit the requirements of various lubricating conditions. The. neutral tar oils Which contain cyclic unsaturated non-benzenoid hydrocarbons have been found to possess in high degree the property of uniting with bearing surfaces to form an intermediate oily film of extremely low frictional resistance, and this property of oiliness is of particular advantage in that it reduces starting friction and ermits the employment of bearing loads ar in excess of those which can be .used with ordinary viscous lubrication. The mineral oils of petroleum origin often possess a high viscosity but rarely have the property of oiliness to any marked extent. Forthis reason lubricants comprising a blend of the unsaturated neutral tar oils with petroleum oils are particularly valuable in that they may be compounded so as to possess viscous and oily properties to meet almost any condition of ordinary lubrication. The cyclic or ganic hydroxy compounds or primary tar acids have been found to increase the viscos-' ity of the neutral tar oils, and accordingly are used "in compositions Where it is desired to establish conditions more nearly approaching viscous lubrication. For conditions involving unusually high pressures where it is necessary to disperse in the oils solids of unctuous properties, it has been found that the neutral tar oils described above are of particular merit because of their natural adaptabiliity as dispersing mediums and further because they possess in favorable combination the properties of oiliness, low volatility and-low viscosity. A low viscosity is particularly advantageous in this connection ecause of the decreased resistance to internal shear within the liquid itself.

This group of neutral tar oils, a mixture of which in proper proportions with the other materials named comprises the present invention, can be prepared from the essen tially primary or only partially decomposed primary tar obtained by distillation ditions such as are described in United States Patent No. 1,426,159 granted August 15, 1922, tovHenry L. Doherty or in the British patent of Henry 0. Loebell #216,488 of May 23, 1923, but which conditions are quite different from those which give rise to ordinarycoke-oven tar. The tar obtained in either of the above processes is essentially a primary liquid distillate of the fuel, and as a result of the fractionahdistillation of the bituminous material solely by heat carried by a hot gas current, this tar contains the volatile components of the coal or other material in a primary or at most an only partially decomposed condition. This tar oil is therefore clearly distinguishable in both its physical and chemical properties from coke, oven tar and possesses an altogether difierent chemical composition.

The primary or partially decomposed primary tar obtained in the above processes is dehydrated and then distilled, either to itch or coke, and the distillates thus obtaine are treated to produce the neutral oil lubricants in question. Briefly this treatment comprises washing with a caustic alkali in either equivalent or insufficient proportions, de-

pending on whether it is desired to remove all or only a portion of the cyclic hydroxy compounds present in the distillate. The neutral tar oil remaining after this treatment can be further treated to remove wax or otherwise to improve its properties by the application of methods similar to those generally employed in refining lubricating stocks from petroleum oil.

The proportion of unsaturated hydrocarbons in these essentially primary tar oil s varies from about fifty percent in oils taken.

from the most primary type to over eighty percentin oils from tars that have been partially decomposed. Apparently it is the high content of cyclic unsaturated non-benzenoid hydrocarbons in theseneutral tar oils which is mainly responsible for the greatly increased property of oiliness which they exhibit eitherwhen used alone or when compounded with petroleum lubricants.

In preparing a mixture of these neutral tar oils with ordinary petroleum oilfor the purpose of securing a product containing the proper ratio of oily and viscous properties to meet the requirements of any particular condition, the viscosity of the compounded oil may be reduced below that found necessary to maintain a continuous layer between the rubbing surfaces under the existing conditionsof rotational speed and hearing pressure. For light loads the neutral tar oils which are obtained by removing tar-acids and wax from the high-boiling distillates havesuificient viscosity in themselves to make them entirely satisfactory. As a cheaper lubricant for unexacting conditions the fractions containing the higher boiling non-corrosive members of the tar-acid group which are present in the original distillate can be used in natural blends, or these high boiling primary'tar acids can be esterified (as by benzenesull'onic acid) to roduce more viscous products; The midd.e-boiling neutral tar-oils arepeculiarly adapted for use as a vehicle for graphite or other dispersed solid lubricant, not only because of their particular adaptability as dispersing media but also because in their natural form they possess a very favorable combination of the properties of low volatility and low viscosity.

The following examples are cited as being representative of some of the types of lubricants which may be made:

(a) For ordinary viscous lubrication:

1040% of primary tar acids of which at least 50% boil above 220 C.; 30-60% of cyclic unsaturated non-benzenoid hydrocarbons; the balance consisting of dead or chem: lcally inactlveoils of slmilar boiling range containing naphthenic, parafiinoid or other saturated hydrocarbons together with small quantities of impurities such as nitrogen and sulphur-containing compounds.

(1)) For oily or greas lubrication:

Less than 10% high lioiling primary tar acids; 45-85% of high-boiling cyclic unsaturated. non-benzenoid hydrocarbons; the balanee consisting of naphthenic and paraflinoid hydrocarbons of similar boiling range con- .taining small amounts of impurities; and the whole in blend with varying proportions of ordinary petroleum lubricants.

(c) For oily or greasy lubrication under extreme conditions a composition such as described in (b) above used as a dispersing medium for finely divided or colloidal graphite or other unctuous material, 0.25% (twenty-five hundredths per cent) of which is av favorable proportion.

It is not intended thatthe invention should be so limited in scope as to include only compositions containing the neutral tar-oils and high-boiling tar-acids which are obtained from a primary liquid distillate of bituminous material such as is produced by the Doherty or Loebell processes above referred to, since any oil can be used which contains cyclic unsaturated non-benzenoid hydrocarbons of similar nature, no matter by what means it is produced, so long as it contains said hydrocarbons in amounts sufiicient to impart the requisite property of oiliness to the final lubricating composition.

The cyclic unsaturated non-benzenoid hy-' drocarbons which make up a large proportion of the neutral tar oils used in compounding the above lubricants, are not claimed as such in the present ap lication. These cyclic unsaturated hydrocarbons are believed to be range.

properties which make which are to be 'found in an essentially r primary tar such as that described. Ac-' cordingly, this term primary tar acids is used genericall to describe the high boiling alkali so uble hydroxy compounds 7 closely related to the phenols and comprising hydrogenated and alkylated or both hydrogenated and alkylated derivatives of phenol and phenol homologues which are present in such tar oils, and of which at least 50% boil above 220 C.

The term cyclic unsaturated non-benzenoid hydrocarbons as used in the claims is intended as a generic term to describe the mixture of cyclic unsaturated non-benzenoid hydrocarbons which make up a large proportion of the neutral oil fraction of such primary tar oils, and which are hydrogenated or alklyated or both hydrogenated and alkylated derivatives of benzene, naththalene, anthracene and homologous cyclic and polycyclic hydrocarbons of the benzenenaphthalene series. 1

The term dead oils as used in the specification is intended to describe the small proportion of hydrocarbons in the neutral oil fraction of primary tars which are not cyclic unsaturated hydrocarbons, but which consist principally of saturated paraffins and naphthenes.

The preferred form of the invention having been thus described, What is claimed as new is:

1. A lubricating composition containing cyclic unsaturated non benzenoid hydrocarbons in admixture with naphthenie and paraffin'oid, hydrocarbons of similar boiling 2. A lubricating composition containing cyclic unsaturated hydrocarbons, naphthenic and parafiinoid non-benzenoid hydrocarbons of similar boiling range, and primarytar acids of which at least fifty percent distil above 220 C. V

3. A lubricating composition containing cyclic unsaturated non-benzenoid hydrocarbons in admixture with a. petroleum oil lubricant.

4. A lubricating composition containing cyclic unsaturated non-benzenoid hydrocarbons and naphthenic and parafiinoid hydrocarbons in admixture with a petroleum oil lubricant. i

5. A lubricating composition containing cyclic unsaturated non-benzenoid hydrocarbons, high boilin primary tar acids and a petroleum oil lu ricant.

6. A lubricating composition containing 5 cyclic unsaturated non-benzenoid hydrocarbons and a small amount of graphite.

7. A lubricating composition containing cyclic unsaturated non-benzenoid h drocarbons, high-boiling primary tar acids, and

graphite.

8. A lubricating'composition containing cyclic unsaturated non-benzenoid hydrocarbons, a petroleum oil lubricant, and graphite. 9. A lubricating composition containing cyclic unsaturated non-benzenoid hydrocarbons, primary tar acids, a petroleum oil lubricant and a small amount of graphite. 10. A lubricating composition containing 2 more than ten percent high-boiling primary tar acids and more than thirty percent gy'clic unsaturated non-.benzenoid hydrocarons.

11. A lubricating composition containing more than ten percent primary tar acids and more than thirty percent cyclic unsaturated non-benzenoid hydrocarbons together with a lubricating oil of petroleum origin.

12. A lubricating composition containing primary tar acids of which at least fifty percent boil above 220 C., and more than forty-five percent of cyclic unsaturated nonbenzenoid hydrocarbons.

13. A lubricating composition containing primary tar acids, and more than forty-five percent of cyclic unsaturated non-benzenoid hydrocarbons in a blend with a petroleum oil lubricant.

14. A lubricating composition containing more than forty-five percent of cyclic un- -40 saturated non-benzenoid hydrocarbon tar oils in a blend with a petroleum oil lubricant. I

15. A lubricating composition containing at least forty-five percent cyclic unsaturated non-benzenoid hydrocarbons together with about twenty-five one-hundredths percent of finely dispersed or colloidal graphite.

16. A lubricating composition containing at least forty-five percent of cyclic unsaturated non-benzenoid hydrocarbons in admixture with a petroleum oil lubricant and a small amount of finely dispersed graphite.

17. A lubricating composition containing I cyclic unsaturated non-benzenoid hydrocarbons and hydrocarbon oils of high temperaa ture coal tar origin.

In testimony whereof I ailix my signature.

ALBERT L. KLEES.

crn'rlrlcare or CORRECTION.

Patent No. 1,121, 109.

Granted September 3, 19 29, to

ALBERT L. sums.

It is hereby certified that error appears in-the printed specification of the .above numbered patent requiring correction as follows: Page 3, line 83, for the word "and" read "or"; same page, line 116, claim 2, after the word "unsaturated" insert the compound word "'non-benzen'oid", and" line 117, strike out "non-'henzenoid"; and that the said Letters Patent should be read with these corrections therein that the same may conform to therecord of the case in the Patent Office.

Signed and sealed this 29th day of October, A. D. 1929.

(Seal) I M. J. Moore, Acting Commissioner of Patents.