US2121151A - Oil for withstanding high bearing pressures and method of making the same - Google Patents

Description

r from the following description. Its viscosity mayvary considerably, depending Patented-June 21, 1938 I UNITEDSTATES PATENT OFFICE OIL FOR WITHSTANDING HIGH BEARING- PRESSURES. AND METHOD OF MAKHWG THE SAME i Charles B. Karns, Pittsburgh, Pa., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application May 2, 1934,

Serial No. 723,505

20 Claims. (Cb 87-9) The present invention relates to improved and which may be characterized by Viscosity lubricating oils, especially to oils of high quality- Indices well above 100. and capable of withstanding high bearing pres- The oil which is selected for the present pursures. The invention will be fully understood pose should be of good color and well refined.

Leaded or lead-containing oils have been used upon the s'ervice'f or which the oil is destined. for a considerable period of time because of their For some purposes a viscosity from 50 to 60 ability to withstand heavy loads and leadoleate seconds Saybolt at 210 F. to 80 or 90 is satisfacis the most generally used substance employed in tory, but for gear or transmission oils for heavier e their manufacture. Unfortunately, lead oleate service higher viscosities are desirable, say above 10 and the lead salts of most of the similar fatty 100 or 120 at 210 F., and they may be as high acids are not freely soluble in high grade lubrias 200 or 250 for particularly heavy duty. The eating all bases, such as cylinder oils, bright stocks base oil is first subjected to a mild oxidation and the like, derived from wax bearing crudes. treatment which is preferably carried out by On standing for a relatively short time the lead bubbling air or other oxidizing gas through the 15 compound is observed to settle from the oil in a oil, while maintained at a temperature of the thick sludge. The lower grade base oils, howorder of 400 to 450 F. The time required for ever, are capable of maintaining the oil in a the treatment depends on the temperature and stable form and it is for this reason that such the rate of air flow, and the conditions may be of leaded lubricants. to which the lead may be added in a stable form.

The low grade base oils which are ordinarily To illustrate the conditions which might be used, used in making up leaded lubricants are generit is found that at a temperature of 450 F. air ally characterized by a Viscosity Index of 50 or may be bubbled through 3 gallons of oil ata below, see Davis and Dean, Chemical and Metalrate of about 2 cu. ft. per hour for a time of lurgical Engineering 36-618 (1929) for a definiapproximately 2%; hours. These conditions vary tion of the term Viscosity Index. It is true considerably for different stocks. At the end of that asphalt containing residual oils such as black this time the, other ingredients of the compound oils f m wh h r Viscosity n ex an 50 are added and it is found that they are capable of have been used, but in all cases it is believed that remaining in the compound in a stable form. The 30 whether distillate or residual, the base oils used oxidation required is very mild and the chemical for the manufacture of leaded lubricants are effect is not clearly known. While oxidation with ordinarily characterized by Viscosity Indices beair or oxygen is preferred other oxidizing agents low 80. Such oils are ordinarily derived from may b u ed and it is not necessary to treat the naphthcnic or s a as ud s. a t fr m entire base oil, in fact only a portion need be so 35 the higher grade crudes such as are charactertreated and later added to the bulk, nor is it ized y e presence of wax. v necessary that the oil treated be a portion of The present invention relates to a lubricating" the b t ck it e1f, i oil con ainin a hi h grade base which is capable One of the constituents added to the'base is, 40 of maintaining the leaded c d in Stable of course, the lead soap or salt, and it is preferred o The base Oil used in the preshnt to use lead oleate,'which is the most widely availtionl Which is normally incapable f holding the able substance of the type. Other lead comleaded compound in solution, is characterized by pounds, of course, maybe used, h as the 1ead halving the Viscosity Index above 60 for distilsoaps of other fatty acids, stearate, palmitate, lat s a d above 80 for residual oils free from ricinoleate, resinate or other soap normally in- 45 a p nd m y h v a V i y Index of 85, soluble in the high quality base. The lead soap is or even hi h r- It s p b e t p d stable, ordinarily added inproportion below about 10% light colored, clean and transparent oils containof t 1 for le, it may be within the ing lead in effective quantities from oils of Pennrange of 5 t 15%, r, as expressed in t rm of sylvania quality or even better, such as the hydrot l h d, from 1 t 3%, 5o a d petroleum oils, a d the high grade oils A sulfurizing agent is also added to the comproduced from solvent extraction processes. and pound to make the product effective in carrying even from synthetic oils produced by condensaheavy loads The sulfurizing agent, is preferably tion of cracked or dehydrogenated wax, either of the "corrosive type, by which is meant that it alone or condensed with aromatic hydrocarbons. is of the class of sulfur compound capable of disi low grade base oils are used in the manufacture interadjusted with ease so as to obtain products 20 I inorganic sulfur compound, such as a sulfide;

coloring a bright copper strip when allowed to stand in the liquid for several hours at 212 1''. according to the general conditions of the A. S. T. M. corrosion test. It will be understood that non-corrosive sulfur compounds may be used, but the corrosive type is so much preferable for the present purposes that they should always be used where possible. Among the corrosive substances may be mentioned free sulfur and compounds such as occur in the lower grade crudes rich in sulfur and its compounds. Various synthetic materials may also be used particularly those heavy enough not to be lost on heating, such as animal, vegetable and marine oils, sulfurized by the action of free sulfur at elevated temperatures, and the products of reaction of these materials with other lmown sulfurizing agents. Synthetic materials may be produced by first halogenating fatty oils, fats and waxes, such as parafiin wax, and then reacting the halogenated product or after dehalogenation, with an hydrosulfide, various polysulfides of alkali and alkaline earth metals. The reaction is readily accomplished at about 200 to 300 1?. and the sulfur gradually replaces the chlorine or other halogen.

The various sulfur compounds mentioned above are to be considered merely as illustrations of the type of sulfurizing agents that may be employed. They are added to the oil so as to furnish about /2 to 5% of sulfur. The sulfurizing agent may be added along with the lead compound or they may be added separately, or the sulfur compound may be added to the oil prior to the mild oxidation treatment referred to above.

By the above methods it is possible to produce leaded oils of higher quality than are previously known, in that it is possible to use bright stocks and cylinder oils derived from the finest crude sources. It is sometimes observed that the Viscosity Index of the finished compound is less than that of the base added and this is due to the effect of the particular sulfur compound added, but ity y with smooth friction-loadcurves.

The following examples are presented to illustrate the method of producing compounded oils according to the present invention and of their properties.

Example I The oil base selected was a heavy Pennsylvania cylinder oil, bright stock, having a viscosity of sec. Saybolt at 210 F. and 100 VI. Three gallons of this stock is mildly oxidized by blowing air thru while at 450 F. for about 2% hours. The oil became slightly more viscous but did not change substantially in appearance. To the oil is added 1% of flowers of sulfur and the oil was held at 400 for about half an hour while agitated. The product is then cooled and 10% of lead oleate gradually incorporated.

The final product is of excellent apearance, only a few shades darker than the original oil.

When tested on the Almen machine, described in Automotive Industries 11/19/32 vol. 67 No. 22, page 650, it was capable of carrying the full load 'of 15,000 lbs. and the friction curve was smooth.

The final value of friction was 32 pound feet.

This oil was stable while similar oils made up with the untreated oil quickly settled out.

Example II A Pennsylvania steam refined cylinder oil was incorporated with 10% of lead oleate and the mixture blown with air at 450- F. for about 2 hours, the rate being about the same as in the previous example. To the mixture is added 1% of sulfurized pine oil, so that the final blend contained 3%'of corrosive sulfur.

, This oil was of good appearance and stable and on the Almen machine showed about the same result as the oil of Example I.

The present invention is not to be limited by any theory of the mechanism of the oxidation step or to any particular sulfur compound or. ingredient but only to the following claims.

I claim:

1; A method for producing improved lubricating oils comprising, subjecting a high quality lubricating oil base to mild oxidation to increase its solvency for lead soaps and adding a lead soap and then a sulfurizing agent uncombined with the lead of the lead soap. V

2. An improved lubricating oil comprising a lubricating oil which has been mildly oxidized by blowing with an oxygen containing gas, free fromasphalt and characterized by a Viscosity Index above about 50, a lead soap and a sulfurizing agent uncombined with the lead of the lead soap.

3. An improved lubricating 011 comprising a base oil having a Viscosity Index above 80 and a viscosity above about 50 seconds Saybolt at 210 F., lead oleate and corrosive sulfur uncombined with lead of the lead soap, the base having been mildly oxidized while at about 450 F. with an oxygen containing gas only to such a degree as to render the finished oil stable.

4. An improved lubricating oil comprising a base oil having a Viscosity Index above about 80 and a viscosity-above about 100 seconds Saybolt at 210 F., lead oleate in proportion of about 5 to 15%, and corrosive sulfur in proportion from about to 5% uncombined with the lead of the lead soap, the base oil being mildly oxidized at a temperature of the order of 400 to 450 F, by blowing with an oxygen containing gas for a time sufilcient only to render the finished compound stable.

5. A method for producing improved lubricating oils comprising, mildly oxidizing a lubricating oil of Viscosity Index above about 50 with air to such a degree as to maintain a lead soap in stable form, and adding to the oil 5 to 15% of a. lead soap and an organic sulfurizing agent uncombined with the lead of the lead soap in an amount suilicient to furnish to 5% of sulphur.

6. A method for producing an improved high pressure bearing lubricating oil comprising subjecting a petroleum lubricating oil base characterized by a Viscosity Index above 80 to a mild oxidation treatment at a temperature of the order of 400 to 450 F. and for such time as to adapt it to maintain lead oleate in a stable form, addin to the oil 5 to 15% of lead oleate and to 5% of corrosive sulfur uncombined with the lead of the been mildly oxidized'at about 450 F. with an 8. Process of manufacturing an improved lubricating oil comprising adding to a base oil having a Viscosity Index above about 80 and a viscosity above about 100 seconds Saybolt at 210 F.,

which has been mildly oxidizedat a temperature of the order of 400 to 450 F. by blowing with oxygen containing gas for a time suflicient only to render the finished oil stable, tree suliur in thefproportion of about $5 to 5% and holding the mixture for a prolonged period at a reaction temperature to permit reaction between the sul- !ur and the oil, followed by the addition thereto 01 5 to 15% of lead oleate.

9. An improved lubricating 011 comprising a refined base oll distillate having a Viscosity Index above 60 which has been mildly oxidized by blowing with an oxygen containing gas, a lead soap soluble therein and a minor quantity of a substance selected from the class consisting of free sulfur and sulfur compounds of mineral, vegetable and animal oils. 1

10. A composition in accordance with claim 9 in which said lead soap is prment in the proportion of from 5 to 15%. 11. A composition in accordance with claim 9 in which said lead soap is present in the proportion of from 5 to 15% and said substance selected from the class consisting of free sulfur and sulfur compounds of mineral, vegetable'and animal oils is present in an amount sufllcient to furnish to 5% of sulfur.

12. An improved lubricating oilcomprising a residual oil free from asphalts having a Viscosity Index above BO'which has been subjected to mild oxidation by blowing with an oxygen containing gas, a lead soap and a substance selected from the class consisting of tree sulfur and suliur compounds of mineral, vegetable and animal oils.

solving therein a lead soap.

18.7A composition in accordance with claim 12 in which said lead soap is present in the tion of from 5 to 15%.

14. A composition in accordance with claim 12 in which said lead soap is present in the proportion 0! from 5 to 15% and saidsubstance selected from the class consisting of tree sulfur and sulfur compounds of mineral, vegetable and animal oils is present in an amount sufllcient to furnish from V to 5% oi sulphur.

. 15. ,An improved stable composition comprising a refined base oil having a Viscosity Index above i 50,-which has been subjected to mild oxidation to increase the solvency of the oil for. lead soaps, said base oils previous to oxidation being partial or non-solvents for lead soaps, and a lead soap dissolved therein.

16. Composition in accordance with claim 15 in which said lead soap dissolved therein is lead oleate in the proportion of from about 5 to 15%.

17. Process for producing a stable lubricating oil lead soap composition comprising mildly oxidizing high grade lubricating oils which are partial or non-solvents for lead soaps and are characterized by Viscosity Indexes above about by blowing with an oxygen containing gas, and dislflaProcess in accordance with claim 17 in which said lead soap dissolved in the oxidized high grade lubricating oil is lead oleate in the proportion from about 5 to 15%.

19. An improved stable composition comprising a refined base oil of the class consisting of distillates having Viscosity Indexes above and residual oils free from asphalts having Viscosity Indexes above which have been mildly oxidized by blowing with an oxygen containing gas, and a lead soap.

20. Composition in accordance with claim 19 in which said lead soap is from about 5 to 15% of lead oleate.

CHARLES B. KARNS.