US2281705A - Extreme pressure lubricant - Google Patents

Description

Patented May 5, 1942 v UNITED STAT ES PATENT OFFICE ax'rnnm: ra'nssmm Lonalcan'r na Egan-rill, Long n 3, Calif., assignor a on Comm! ornia, Los Ange Calif., a corporation of California I,

No Drawing. A plicatlon January 3, 1940, Serial No. 312,227

14 Claims.

- This invention relates to lubricants and par ticularly to extreme pressure lubricating oils.

This is a continuation-in-part of my earlier application, Serial No. 745,169, filed September 22,

1934. The primary object of the invention is to develop lubricants for severe pressure operating uses which will be stable, free from acid, and at the same time possess the necessary high loadcarrying characteristics. Heretofore sulfur chlorinated oils such as those obtained by treatment of mineral oils and fatty oils with sulfur chloride have been employed as extreme pressure bases for addition to mineral lubricating oils, but these I have not been satisfactory for the reason that they have been unstable and usually could not be entirely freed from mineral acid, inasmuch as hydrogen chloride is usually developed at comparatively low temperatures. I have discovered, however, that various mineral oil fractions can be directly chlorinated by contact with chlorine gas so as to produce substantially stable, acidfree chlorinated derivatives which may be added to lubricating oils to impart to said lubricating oils the characteristics necessary to adapt them especially to extreme pressure or high load-carrying uses.

The invention therefore may be stated as residing in chlorinated petroleum fractions to be used as extreme pressure bases in the preparation of extreme pressure lubricants, wherein the chlorine is chemically combined with a normally non-.volatile mineral oil fraction, as by direct contact of chlorine gas with the fraction. The invention includes also the lubricant wherein a quantity of mineral lubricating oil or the like contains such a chlorinated petroleum fraction. The invention resides also in a method of producing lubricants of the stated character, the

chlorination being accomplished by direct contact of the free chlorine with the fraction being treated. The invention refers particularly to the tion is carried. Where such more parafllnic oils,

as for example waxy lubricating dlstillates, are chlorinated with difficulty, iodine or other catalystls may be added, as in chlorinatiohs in genera Considering the invention in greater detail, I

have discovered that any normally non-volatile petroleum fraction may be chlorinated by direct contact of chlorine gas with the fraction to produce chlorinated products whose chlorine content will vary with the time and conditions of chlorination. While straight run lubricating oils may be employed as the stock to be chlorinated, I have discovered that aromatic petroleum frac tions are more-susceptible to'chlorination than the non-aromatics. For example, cracked gasoline, cracked cycle stocks, j cracked residuums and products from the cracking of highly naphthenic crude oils may be employed. Likewise, the extract obtained by the use of liquid sulfur dioxide and similar solvents such as, sulfur dioxide furand benzene, BB dichlorethyl ether, phenol, an-- iline, nitrobenzene, cresol and furfural, are especially suitable, for chlorination to produce the extreme pressure bases of this invention. The llqfur contents ranging ordinarily from about .25%

chlorination of aromatic fractions such as the fraction soluble in liquid sulfur dioxide and commonly known as "Edeleanu Extract and tofractions derived from cracking operations such as cracked gas line, cycle stock, cracked residuum,

and the various fractions from highly naphthenic crude oils, these being particularly susceptible to chlorination. However, oils oi more paramnic character may also be employed for chlorination, at least for some uses, the permissible extent of dilution however with an ordinary lubricating oil usually being not so great, although this will I also vary with the extent to which the chlorina- 55 be greatly increased, for example. to as high as to about 3% or 4%, an average kerosene extract being about 1.25%. These facts are common knowledge in the industry. The waxy lubricating distillates are of course open-chain compounds. 1 i

Any of these materials may be chlorinated to produce a varying chlorine content, for example, from 5 or to hr chlorine, and the resultant chlorinated material added to mineral luadded to anysuitable lubricating stock from either Eastern or-Westem oils or blends thereof, or the percentage may be decreased, or it may 40 or sea, depending upon the degree of chicrination. or the chlorinated bases and the degree of extreme pressure characteristics required.

@hlorination may be readily efiected in any suitable type of protected apparatus such as leadlined or glass equipment, the chlorine in gaseous form being bubbled through the material to be treated at. any desired rate and under any condition adequate to produce thorough contact so that a desired percentage of chlorine may be combined chemically with the fraction under treatment. Iodine or other catalysts may be employed where necessary or desirable, for example where the more paramnic oils such as waxy lubricating distillates are otherwise chlorinated with dimculty.

As an example, Edeleanu extract obtained from a kerosene or lubricating oil fraction by treat= ment with liquid sulfur dioxide to obtain the extract in the liquid sulfur dioxide which is then expelled from the extract, may be treated in apparatus such as above described by bubbling gaseous chlorine therethrough for a period of iii to so hours at a temperature of about 140 F. or between about 120 F. and ice i The resultant chlorinated material is then washed with dilute alkali to remove hydrogen chloride and decompose any very reactive or unstable chlorinederivatives, thereby leaving only those chlorine derivatives which are at least moderately stable toward hydrolysis. Vigorous treatment with alkali is ordinarily avoided. Instead of treatment with atkali, the reaction product may be merely washed with water, preferably with'open steam agitation, and/or treated with decolorizing clays at temperatures of for example ec F. to too F. This chlorinated product is then ready for addition to any of the previously mentioned lubricating oils in whatever percentage may be desired for a given use as herein indicated.

Chlorinated Edeleanu extracts as above. described are ordinarily entirely soluble in Western or naphthenic base lubricating oils, inasmuch as these oils have good solvent properties for the chlorinated products. Such lubricating oils are the typical naphthenic or asphaltic base type such as California lubricating oils and the like. For example, a California lubricating oil from a naphthenic base crude having a viscosity of 110 seconds Saybolt Universal at 210 F. has been satisfactorily employed where using a chlorinated Edeleanu extract from kerosene. In some instances, however, small quantities of sludgeforming materials or materials insoluble in lubricating oil and also insoluble in the batch being chlorinated are sometimes developed in the chlorination operation, and in those instances, if these insoluble materials are objectionable, their formation may be avoided by giving the Edeleanu extract a light acid treatment with strong acid before chlorination, as with sulfuric, strong sulfonic, chlor-acetic and sulfamic acids. Again,

highly paraflinic lubricating oils sometimes have poor solvent power for chlorinated Edeleanu extracts or portions thereof, and this difllculty may also be overcome by giving the Edeleanu extract an acid treatment before chlorination. For example, I have given an Edeleanu extract from kerosene a satisfactory treatment by agitation with about pounds of 98% sulfuric acid per barrelof 42 gallons. This amounts to about 3% and is classed as a light acid treatment. Depending upon the nature of the Edeleanu extract and its tendency upon chlorination to develop oil-insoluble materials or materials insoluble in the Ill 2' accrues batch undergoing chlorination, the treatment may vary from 4 lb. or 5 lb. of 98% sulfuric acid per barrel to perhaps 12 lb. to 15 lb. per barrel of 42 gallons. in other words, the range is between about 1.5% and about 5% of 98% sulfuric acid.

The acid and sludge are then removed from the treated extract. Upon chlorination of the Edeleanu extract so acid treated, even when treating at temperatures as high as about 200 l t, no

materials are developed which are insoluble in.

Westem oil, and likewise they are usually completely soluble in Eastern or parafinic oils. Another advantage in acid treating the extract before .chlorination is that chlorination may then be extended from or to as high as or without interfering with the compatibil ity of the product in themineral lubricating oil selected.

This is in addition to the fact that the mmperature range may be extended to lie between'about F. and 200 bi, although in general a desir= able average operating temperature is probably about 352- A As in the case of the chlorinated non-acidtreated Edeleanu extract, the product may be water-washed and washedwith dilute alkali such the caustic soda, and where there are tendencies towards emulsification these may be avoided in various ways as by using stronger caustic solu tion rather than weaker solution or by chlorinat= ing the product to a lower degree for example 10% to 15% chlorine content, or by employing a fortified spent alkali solution, or in other ways known to the petroleum chemist. For purposes of clarification the washed chlorinated material may be heated with 5% to 10% of any appropriate decolorizing clay, and followed by filtration. These chlorinated materials from acidtreated Edeleanu extract are soluble to the required extent in both Eastern and Western oils,

.- and exhibit suitable extreme pressure properties.

For example, various oils containing 12% of chlorinated extracts having chlorine contents of from 15% to 35% have shown a load-carrying capacity without scoring of 50 lb. to 100 lb. on the Timken lubricant and wear tester.

Chlorination can also be accomplished in the vapor phase, the chlorine gas being mingled with the vaporized fraction to be treated, and the resultant materials subsequently condensed. To obtain the necessary vaporization without the use of temperatures at which the reaction would be too vigorous the operation may be carried on at reduced pressure and/or with a carrier gas such as nitrogen or steam. Not only may these chlorinated products be added to mineral lubricating oils and the like, but such oils may in turn be thickened with soaps such as calcium, sodium and aluminum soaps to form extreme pressure greases. Thus, by this invention either mineral lubricating oil stocks or lubricating greases are produced containing chlorine inchemical combination with normally non volatile mineral oils, these products all having extreme pressure characteristics especially desirable for lubrication under heavy loads.

Such extreme pressure service includes not only gear lubricants for conditions of high tooth pressure, but also cutting oils and penetrating oils. In order to increase the oiliness of any of these oils which are to be used at times under intermediate pressure conditions. requiring the characteristics of high oiliness, fatty oils and/or fatty or other oil-soluble organic acids may be included in the composition containing the mineral oil and chlorinated oil. In some instances such iatty oils or acids could be used with the chlorinated oil to the exclusion of said mineral oil. It is also within the scope of this invention to produce miscible oils for cutting, drawing, or other metal working operations, in which high film strength is desirable, by the inclusion in the composition containing the chlorinated compounds suitable emulsifying agents, such as soaps and common solvents such as various alcohols aswell known in the art, to make the composition readily or spontaneously emulsifiable in water.

It is to be understood that anyof the, various fractions herein described may be chlorinated in any manner similar to that described, and may lubricant.

3. A lubricant comprising chlorinated Edeleanu extract.

i. A lubricant comprising Edeleanu extract "having between about and 45% of chlorine chemically combined therewith.

5. A lubricant comprising Edeleanu extract having a chlorine chemically combined therewith exceedingabout 10% of the extract.

6. A lubricant comprising a mineral lubricating 011 containing an amount suflicient to impart extreme pressure characteristics thereto of lightly acid-treated Edeleanu extract having chlorine chemically combined therewith.

7. A mineral lubricating oil containing an amount sumcient to impart extreme pressure characteristics thereto of chlorinated acidtreated Edeleanu extract. v

8. A mineral lubricating oil containing an amount sufficient to impart extreme pressure characteristics thereto of chlorinated Edeleanu extract which has previously been treated with between about 1.5% and 5% of 98% sulfuric sure lubricant base comprising treating Edeleanu extract with about 1.5% to 5% of sulfuric acid having aconcentration in the order of 98%, removing the acid and sludge from the extract, chlorinating the acid-treated extract to cause the chemical combination of chlorine with the extract to impart good extreme pressure-properties, and washing the chlorinated extract to remove unstable materials.

13. A method according to claim 12 and the additional step of commingling a minor proportion of said chlorinated extract with minera lubricating oil.

14. A method of producing an extreme pressure lubricant base comprising treating Edeleanu extract to remove constituents which would form sludgeor oil-insoluble materials, and chlorinating the treated extract to cause chemical combination of chlorine therewith and impart extreme pressure properties.

DAVID R. MERRILL.