US2741649A

US2741649A - Lubricating oil and process for forming the same

Info

Publication number: US2741649A
Application number: US337764A
Authority: US
Inventors: Andrew D Abbott; Lloyd F Brooke
Original assignee: California Research LLC
Current assignee: California Research LLC
Priority date: 1953-02-19
Filing date: 1953-02-19
Publication date: 1956-04-10
Anticipated expiration: 1973-04-10

Description

April 10, 1956 A. D. ABBOTT ET AL 2,741,649

LUBRICATING OIL AND PROCESS FOR FORMING THE SAME Filed Feb. 19, 1953 n 305 s @N R j m mi N x N 0 R 3 E F O V ED IT N Dnv, I w w AL Y D A |N| m B m m N 1 x M9205 w o 1 x aux/2M5 1 15% n a v n mos/Gm s 9 I vw w m 4 am I I /m a s m w o. m. S m w. N 3 H1105 \w .2 3 zrmjo w d 2 E v. 1 wzrmjo NW :ZUUZOU \l 27 5 6 k\ v a mxmm o Pro.

United States Patent LUBRICATING 011. AND rnocnss son FoRMING Y rrm SAME Application February 19, 1953, Serial No. 337,764

14 Ciaims. (Cl. 26(i-6S3.-i)

This application relates to the provision of a novel lubricating oil and a process for producing this oil. More particularly, the invention concerns a process Wherein hydrocarbon waxes petroleum or other origin are reacted with olefins, especially ethylene, to produce a lubricating oil of outstanding characteristics. This application is a continuation-in-part of our copending applications, Serial Nos. 281,446 and 281,447, both filed April9, 1952, and now abandoned.

It has long been recogn zed that hydrocarbon waxes have good lubricating qualities as long as they are maintained in the molten condition. Thus, such waxes have good lubricity, a high viscosity index, and good stability. On the other hand, it is obvious that waxes can have but a limited utility as lubricating oils due to their high melting, or pour point. If this deficiency of waxes could be overcome, the resulting liquid products would receive serious consideration for many lubricating applications since the waxes themselves are available in a wide range of viscosities. Accordingly, it is an object of the present invention to provide a treatment whereby hydrocarbon waxes are so altered in structure as to efiect a major'reduction in their melting point while at the same time preserving the desirable ubricating, stability, viscosity and viscosity index qualities of the Wax.

While attainment of the foregoing object has the efiect of providing the art with a novel lubricating oil, the synthetic oil art has now progressed to the point where no such oil can meet with general commercial acceptance unless it possesses truly outstanding and unique characteristics. This is particularly the ease with synthetic oils proposed for use as crankcase lubricants in automotive or other internal combustion engines since such oils are considerably more costly than natural petroleum oils and must justify the added expenditure. Experience in the field shows that a successful synthetic crankcase oil, in addition to having excellent lubricating and viscosity characteristics, should also be fully compatible with and respond well to treatment by, the various additives such as anti-oxidants, detergents, corrosion inhibiting agents, blooming agents, and the like which now are conventionally incorporated in crankcase lubricating oils. It is also important that the synthetic oil be compatible in all proportions with natural mineral oils. This is a factor of considerable importance from the practical standpoint, for not only does it permit the marketing of a variety of blends, each of which is particularly well adapted for a given climatic or other condition of usage, but'it also permits the operator of the vehicle to replenish the main body of synthetic oil in the crankcase with a conventional oil, if need be, without danger of forming an incompatible mixture in the crankcase. While a number of difierent synthetic oils are now available, none fulfills all these desirable attributes, and it is therefore a further object of this invention to provide from waxy hydrocarbons a novel synthetic oil of satisfactory pour point characteristics which couples good lubricating, viscosity and viscosity index qualifies with a high degree of com.-

ice

patibility with mineral oils and with the various oil additives, and which responds weil to treatment by said additives.

Another important quality of an automotive crankcase lubricant relates to the amount of deposit which the oil leaves in the combustion chamber as the engine is operated. Such combustion chamber deposits, whether attributable to the oil or to the fuel, have the efiect of increasing the octane requirement of the engine. Due to the added costsof premium fuels, it is desirable to keep this octane requirement increase as low as possible even in the case of those engines having a relatively low initial octane requirement. The problem becomes even more serious with many of the modern high compression engines which require the use of premium fuels even when the motor is clean. Accordingly, it is a highly important object of this invention to provide a lubricating oil which not only possesses the desirable compatibility and other characteristics outlined above, but which also has outstandingly low deposit-forming characteristics when employed as the crankcase lubricant in an automotive or other internal. combustion engine.

The nature of still other objects of this invention will appear as the description thereof proceeds.

We have now discovered that the foregoing objects are attained by reacting a hydrocarbon wax, or mixture of said waxes, with one or more olefin compounds, and preferably with ethylene. This reaction, which is conducted under elevated conditions of temperature and pressure, proceeds to a certain extent even in the absence of a catalyst, though it-is greatly specded up and the nature of the product oil improved by using chloroform, methylene chloride or other alkyl-halide as the catalyst.

The oils which can be obtained in this fashionhave relativeiy low pour points, good lubricity and a high viscosity index. They are available in a wide range-of viscosities and hence are adapted to be employed: as crankcase lubricants in automotive engines, as well as for other lubricating purposes. They are compatible with mineral oils in all proportions and at any desired temperature, and blends of outstanding quality have been prepared. They are also fully compatible, when employed either alone or in a mineral oil blend, with the various oil additives, and they respond well to treatment by said additives. In these as well as other particulars, the present oils are far superior to other types of synthetic oils which are presently available on the market.

The oils of the present invention are also characterized by abnormally low deposit-forming characteristics when employed as crankcase lubricants in internal combustion engines. In consequence, the use of said oils (or of ineral oil blendsv containing substantial amounts of the present oils) in a clean engine has the effect of establishing a lower ultimate octane requirement than is the case when a conventional mineral oil is employed alone, the same fuel being used in both cases. While the present oils thus make for improved engine performance by reducing engine. deposits, it should also be noted that the high viscosity index of these oils makes it possible to employ a much light r grade thereof than would otherwise be practical and thereby efiect a significant reduction in frictional losses as compared with those experienced when a heavier-grade of oil is used. Any such reduction in frictional loss is accompanied by a corresponding increase in the mileage obtained with any given fuel.

The waxy compound, or mixture or" such compounds, to be reacted with the olefin can be any hydrocarbon of predominantly open-chain configuration which contains from about 15 to carbon atoms in the molecule, and which is substantially free of aliphatic unsaturation. Included are various members of the parafiin series of hydro: carbons such as pentadecane, hexadecane (cetane'), 2-

methylheptadecane, 4-propylnonadecane, eicosane, pentacosane, octacosane, triacontane, tritetracontane, heptaconcane and the like, as well as hydrocarbon compounds Containing a long hydrocarbon chain such as dodecyl cyclohexane, octadecylbenzene, 2-octadecyldecalin, and tetradecylcyclopentane. Also included are various erystalline and micro-crystalline .parafiin waxes, including slack and petrolatum waxes and wax mixtures, ceresin, o'zokarite and polyethylene waxes as well as those derived from the Fischer-Tropsch synthesis or by the destructive or non-destructive hydrogenation of synthetichydrocarbons, coal,'shale oil or the like. These waxes, many of which are made up of a mixture of various hydrocarbon compounds and which frequently contain small percentages of other, non-paraffinic compounds such'as naphthenes and the like, can be employed either in the form in which they are recovered, or they can first be separated into particular compounds, fractions, or mixtures of such compounds or fractions, with the separated component(s) then being reacted with olefin to form the oils of the present invention. Of the available hydrocarbon wax reactants, 'a preferred class for the purpose of this invention is made up of the various crystalline and micro-crystalline waves which are recovered from petroleum oils; these parafiin waxes consist essentially of saturated, open-chain petroleum refining processes, and such mixtures can be employed directly, if desired. Ethylene, whether employed alone or as the principal constituent of a gaseous mixture, constitutes the most preferred olefinic reactant. Otherexarnples of olefinic reactants which can be' employed in this invention are pentene-l; pentene-2; 2- 'r'nethylbutene-l; cyclopentene, cyclohexene, 3-methylbutene-l; 2-methylbutene-2; hexene-l; 3-methylpentene- 2; heptene-l; octene-l; octene-2; decene-l; and decene-2.

' 'As indicated above, the present reaction proceeds in the most favorable manner in the presence of a catalyst, and a suitable material of this class is therefore preferably employed. The only compounds which have been demonstrated to have a beneficial catalytic action in the processor this invention are the hydrocarbyl halides, and more particularly the alkyl halides. Included within this term are such compounds as chloroform, methylene chloride, methyl chloride, carbon tetrachloride, tetrachloroethane, 'dichloropropane, butyl chloride, chlorinated naphthas, methylene fluoride, propyl bromide, octyl iodide, dichlo ro-monofiuoromethane, and the like.

' In "carrying out the reaction of olefin and wax, there is-employed from about 1 to 25 moles of the olefin per mole of wax. A preferred reactant ratio, however, is from about 2 to 10 moles of olefin per mole of wax. The amount of catalyst to be employed will vary somewhat depending on the nature of the reactants, as well as upon the particular catalyst material, or mixture of said ma terials, which is used. In general, good results have been obtained by using from 0.1 to 10% by weight of the catalyst, while a preferred range is from 1 to 5% by weight,- both of these percentages being based on the Weight of wax charged.

The reaction'of the present invention is carried out, under the elevated conditions of temperature and pressure discussed below, by bringing the olefin into reactive en gagement with the Wax reactant as the latter is maintained in the liquid condition; as aforesaid, a catalyst is preferably present in the reaction mixture also. The wax may be placed in the liquid condition by melting the same or their high pour points. The Minas and Ute Tribal .grudes,

having pour points in some instances as high as .F., are exemplary of such products. These crudes, or waxcontaining distillates or residues obtained therefrom, can be reacted with an olefin in accordance with the process of this invention, with the result that a substantial por- 'tion of the wax present therein is converted to a lubricat ing oil of low pour point. This not only improves the yield of lubricating oil from the starting material, but also so decreases the pour point of said material as to greatly facilitate the handling and refining thereof, When this procedure is adopted, the wax-olefin oil produced is .nor mally left with the other oil as the resulting oil blend has excellent over-all properties. v

The reaction between the olefin and the wax proceeds at temperatures of from about 400 to about 700 F. Superatmospheric pressures are employed, primarily) to promote the solution of the olefin reactant in the liquid Wax material and to maintain the other components of the system in a liquid condition at the elevated temperatures employed. While any pressure between about and 15,000 p. s. i. g. can be employed, pressures between about 1,000 and 4,000 p. s. i. g. are preferred. This presethane or other inert gases can also be employed for this purpose. In such cases, the olefin can be supplied in liquid form, if desired, when physically possible. 7

In carrying out the process of this invention, a number of competing reactions take place, and it is thought that a proper understanding of these reactions is essential to an intelligent expression of the preferred reaction condiditions and operating procedures to be employed. The predominant reaction is believed to be one wherein the wax is alkylated by the olefin; thus, in the case of ethylene, a given wax molecule would acquire at least one, and usually more than one, ethyl side chain; Polymerization of the olefin reactant also plays a significant, though minor 1 role in the reaction, while a third reaction (which normally takes place in very small degree) involves the cracking of the waxy starting material or the alkylated wax product. The cracking reaction is a particularly deleterious one, for if it occurs to any appreciable extent the deposit-forming and additive-responsive qualities of the final oil product are seriously impaired. Fortunately, it has now been found that the cracking reaction can be substantially eliminated by maintaining the reaction temperature below about 700 F. Whiletemperatures between 700 and 800 F. would otherwise be desirable since they have the effect of speeding up the desired alkylation reaction, such temperatures cannot be employed for more than relatively short periods of time if cracking of the wax is to be avoided. On the other hand, temperaturesabove 600 FL are preferably employed Wherever possible so as to speed the reaction as much as possible without otherwise adversely afiecting the course thereof. The olefin poly meriz'ation reaction is also undesirable, though to a lesser extent than is the case with the cracking reaction. We have found that the olefin polymerization reaction can be minimized by gradually adding the olefin to the heated Wax as the reaction progresses, the addition of olefin being made in a continuous or intermittent fashion, as more particularly described below. Accordingly, in the preferred practice of this invention, reaction temperatures between 600 and 700 F. are employed, and the olefin is'added to the heated reaction mixture (preferably along with catalyst) as the reaction progresses. M As indicated above, the reaction time will vary depending on the temperature employed. It also varies with the nature ofthe olefin,reactant and the relative rate at which. the olefin is admitted to the reaction zone, Thus, ethylene is much more reactive than the other olefins and requires a shorter reaction period. As a general rule, however, good results are obtained using reaction periods of from 1 to 20 hours, and in some cases, appreciable reaction will occur in even shorter periods, particularly with ethylene.

a As will occur to those skilled in the art, the reaction may be carried out batchwise, as in an autoclave, semi- I continuously or continuously, as in a tube reactor. The

olefin, moreover, may be charged to the reaction zone all at onetime or in portions. The pressure in the reaction zone may be maintained'by the olefin alone or, as indicated above, an inert gas may be used in aiding maintenance of the desired pressure. The reaction is essentially a liquid phase reaction; that is, reaction occurs between liquid wax and olefin dissolved therein. Accordingly, agitation of the reaction mixture will be found advantageous. Moreover, it is often desirable to avoid too high a concentration of olefin in order to discourage competing reactions, such as the polymerization of the olefin. Therefore, in order to encourage the preferential reaction of addition of olefin to wax and to ensure a more uniform distribution of olefin on the wax molecules, the olefin preferably is gradually charged to the reaction zone as the reaction progresses. In operating batchwise, this can conveniently be accomplished by adding the olefin to .the reaction vessel in successive increments, each of the order of about 5 to 40 per cent of the total olefin charge. After all of the olefin has been added (either with or without an inert gas employed to maintain the desired pressure), reaction is deemed complete in batchwise operations when the drop in pressure substantially ceases. When operating in a continuous, or semicontinuous fashion,'a small amount'of olefin under suitable pressure may continuously be added'to the reaction mixture, or wax and olefin may both be continuously supplied to a suitable reaction zone, with the reaction mixture also being continuously withdrawn from said zone.

Once the reaction between the olefin and wax is complete, the resulting wax-olefin oil can then be separated from the other components of the reaction mixture by a practice of conventional refining techniques as more particularly described below in connection with the drawing. Briefly, however, the separation process normally involves a preliminary distillation to free the mixture of lighter ends (preferably those boiling below 250 F. at 1 mm. Hg) and thereby recover a light oil which is essentially comprised of. polymerized olefin reactant. This is followed by a dewaxing step to remove unreacted waxes. Depending on the severity of the dewaxing treatment, oils are recovered having pour points of from below -6S F. to F. The resulting dewaxed oil products have viscosities which are much'the same as those of the molten waxy starting materials, and vary from about 33 to 80 or more SSU at 210 F. The viscosity index of the present oils normally is well in excess of 100 and preferably 'is 130 or more, except as lowered by the use of a blending oil. 0

.The oil of this invention (apart from any blend thereof with mineral oil) is essentially comprised of the waxolefin alkylation product resulting from the reaction of the wax with the olefin, this product normally comprising from about 60 to 95 by weight of the oil. The balance of the oil is madeup essentially of polymerized olefin reactant. Therelative amount of this component which is presentdepends upon the conditions which were employed in forming the oil, and particularly on whether or not said conditions favored polymerization of the olefins as well as on the severity of the distillation procedures practiced in recovering the oil from the crude reaction mixture. Thus, if desired, the wax-olefin oil of this invention can be obtained in a form substantially free of any polyolefin component by first carefully minimizing the amount of said polymer formed during the alkylation step, and by then subjecting the oil, either before or after the dewaxing step, to a distillation treatment which is rigorous enough to remove the more volatile olefin polymer. Inasmuch as distillation treatments of this character normally lead to serious losses of the wax-olefin alkylate, and since excellent results are obtained with oils containing even relatively large amounts of the polymer, the preferred practice is to obtain as final product an oil which contains from to 90% of the wax-olefin alkylate and from 10 to 30% of the olefin polymer. The oils will also contain a small percentage (usually varying from a fraction of a percentup to about 4 or 5%) of various other materials such as unreacted waxes, partially cracked waxes, and the like. However, these materials make no particular contribution to the properties of the oil and may be regarded as impurities. They therefore have been disregarded in the foregoing statement of the preferred oil composition.

Reference is now made to the accompanying drawing which illustrates diagrammatically a process for carrying out one embodiment of the invention. According to this embodiment of the invention, olefin and Wax are charged to a reactor, such as the coil reactor described in Example 1, either directly or into a mixing line or zone leading into the reactor. After reaction, the reaction products are introduced into a gas separation zone, wherein the light gases are separated from the heavier liquid fractions. Part or all of these light gases may then be bled off the system; or part or all of these gases may be recycled for use as olefins, preferably after treatment in an olefin concentration zone involving fractionation, adsorption or absorption, as is known in the art. The heavier liquid fraction from the gas separation zone is introduced into a distillation zone of one or more stills wherein a further separation light and heavy fractions is effected, the light fraction being recycled or bled oif and the heavier fraction, dewaxed to give the Wax-olefin oil of this invention. This wax, which may vary in amount from about 10 to (in terms of the weight of wax charged) depending on the relative amount of olefin employed and the over-all severity of the reaction, is then available for further reaction with the olefin.

Referring to the drawing, the numeral 2 indicates a Wax storage vessel or tank equipped with heating means, such as coil 3, to render or maintain the wax fluid. The numeral 4 indicates storage vessel or tank for olefins, which may be introduced thereinto through valved line 5,-from an outside source, not shown. Fluid wax from storage tank 2 is introduced through line 7 into reactor 9-, while olefin material, for example, ethylene, is introduced thereinto through line 8. c

After reaction is complete, the reaction products are introduced through line 10 into gas separator 11. Light fraction or gases are removed from the gas separator through line 12. Part or all of these gases may be bled 03 through valved line 13 or part or all recycled to olefin storage 4 through line 14. Overhead from gas separator 13 can be charged through line 15 to olefinconcentrator 16, wherein the olefins are concentrated, and then recycled through liues 17 and 14 to olefin storage, the saturated, or reject fraction being removed through line 18. The heavier fractions from gas separator 11 are charged through line 19 to still 20 to eifect a further separation of lighter and heavier fractions. Thelight fractions from still 20 are removed through line 21, and part or all bled off through line 22 or part or all recycled through line 14 to olefin storage 4. The heavier waxy oil fraction from still 2il is charged through line 23 to dewaxer 24 to obtain a low pour point oil through line 25, and also-wax, which may be recycled to wax storage through line 26. The oil from line 25 may, if desired, be subjected to further distillation treatment to separate the oil into relatively light and heavy grades. 7

The oil of the present invention is well adapted to be asthe initially clean engine was run using a commercial isooctanc fuel."

TheLauson engine was operated continuously for 240 hrs. at 'full' throttle'('1200R.' P. M.) using a 15 spark advance, a'jacket temperature of 210 F., a sump temperature of 150 F. and an air/fuel ratio of approximately 14:1 by weight. At the end of this period the octane requirement had increased by only 22 research numbers when the Wax-olefin oil of this invention was used. In a companion test conducted under the same circumstances, but with a highly refined, wax-free base oil of'SAESO grade having viscosity index of 85 and derived nonrcaliforniawaxy crude, the octane increase was'43"rese'arcnnuniberst 'Theoldsmebile'enginewas operated for a continuous period of"'240"hours' at"2000'R. P. M.', with 35 spark advance, 'aloa'dof 16 brake horsepower, a jacket temperature of 180 F., and a sump temperature of 165 F. Here the octane requirement increased was 5 research numbers with the wax-olefin oil and 14 research numbers with the mineral oil as defined in the foregoing paragraph.

EXAMPLE 4 In this example a micro-crystalline wax mixture obtained from petroleum oil and melting above 175 F.

which had a viscosity of 80 SSU at 210 and an estimated viscosity index of 122 was employed. In carrying out the operation 600 gms. of the wax were charged to a pressure bomb and heated to 665 F To the bomb was then charged 150 gms. of ethylene and 10 gms. of chloroform, the pressure in the bomb then being 1650 p. s. i. g. The bomb was then heated for a period of 74 minutes at a temperature of about 670 F., after which a further increment of 100 gms. of ethylene and 5 gms. of chloroform were added. The heating was then continued for a fur- (her period of 127 minutes, the pressure in the bomb being 1250 p. s. i. g. at the end of this second heating period. On releasing the gas from the bomb there was recovered 710 gms. of liquid product. 118 gms. of this product were then topped to remove the portion (5.3 gms.) boiling below 395 F. (pot temperature) at 1 mm. Hg. The remainder of the liquid product was then solvent dewaxed at 20 F., whereby there was recovered 55.3 gms. of a wax-olefin oil having a pour point of F., a viscosity of 63.2 SSU at 210 F. and a viscosityindex of 135.

7 EXAMPLE About 400 gms. of AMP 125-130 'wax (molecular weight about 375), 215 gms. of ethylene and 10 gms. of chloroform were charged to a bomb. The pressure in the bomb was then 1000 p. s. i. g. -The bomb was heated to a temperature of about 640 F. overa period-of 12 hours and was then held at this temperature for 5% hours, the pressure being 1600 p. s. i. g. as the bomb reached 194 F., 3290 p. s. i. g. at a bomb temperature of 507 F., and 1600p. s.- i. g. as the final temperature of 640 F. was reached. At the end of the.'5%'-h0l.ll-h63ting, the pressure in the bomb had dropped to 650 p. s'. i. g. On releasing the gas pressure within the bomb, there was recovered 586 gms. of liquid reaction mixture which was then distilled to remove the portion boiling below 330 F. at 2.5 mm. Hg. The heavier oil recovered was then solvent dewaxed at -15 F., thereby yielding 401 gms. of oil having a pour point of 5 F., a viscosity of 41.5 SSU at 210 F., and a viscosity index of 143.. When this oil was more severely dewaxed (at -50 1 there was recovered 369 gms. of 'oil having a pour point of R, a viscosity of 41.5 SSU at 210 F.- and a viscosity index of 139.

EXAMPLE'6 The wax-olefin oil having the 35 F. pour point, whose preparation is described in the previous example, was blended with a neutral mineral oil which was'a solvent refined, California paraflin base oil having a viscosity of 150 SSU- at 100 1 a viscosity index of '87 and apour' point of ---5 F., blends being prepared containing between 10% "of the wax-olefin oil and of the mineral oil-to 90% of the waxolefin oil and'10% of the mineraloilu-Th'e'se blends were miscible at all temperatures down to the pour point of the particular blend involved. Forthe sake of comparison, blends were made of the same mineral oil with a conventional synthetic oil of the polyglycol type, the particularpolyglyc'ol chosen being a" methyl phenyl diether of polypropylene glycol having a molecular weight of about 1000. The blends so prepared were miscible only at relatively elevated temperatures; thus, a blend comprising 60% of mineral oil and 40% of thepolyglycol was miscible only at'temperatures above 72 F. When the mineral oil was blended with an equal amount of a synthetic oil comprising a methyl sec. butyl diether of polypropylene glycol having a molecular weight of about 500,'it was found that "the blend was compatible only at temperatures above 18' In another seriesof-tests the wax-olefin oil referred to above was blended with various of the additives" which are customarily employed in lubricating oils. In one such test the oil was found to be compatible with a total of at least millimoles of a calcium petroleum sulfonate and sulfurized calcium phenate per kg. of oil, the phenate normally being used in the proportion of approximately 2 moles for each mole of the sulfonate. On the other-hand, it was found that amounts'as small as 5 millim'oles of said additives per kg; of oil would precipitate out'at room temperature'from a conventional polyglycol oil, here a monooctyl ether of polyglycol acetate having a molecular weight'of about 500.

I It vas'also obs'ervedtha't the additive-containing'waxolefin' oils were not compatiblewith water and that even agitation of the compou'nded oil'"with water did notaffeet the composition. On the other hand, the polygl-ycol compositions were found to be readily compatible with water and the" presence ofas little as 0.2% by weight of Water therein had the effect of causing the immediate decomposition, and precipitation from the mixture, of the phenate additive. W

EXAMPLE 7 In this operation 100'parts of commercial eicosane, whichcontained .6 parts of oil having a 0 pour point, were reacted in a pressure vessel with 45 parts of ethylene for. avperiod of one hour at an average temperature of about 670 F., the pressure. at the beginning of the reaction being 2650p. s. 'i. :g. andjat the end of the reaction, 1600p. s..i. g. On distilling off the portion of thereaction mixture boiling below 250 F. at 1 Hg and then solventdewaxing'the remaining liquid at -20 F"., there was recovered 31.3 parts of a heavy oil having a pout-"point of 0 E, a vis of 37 SSU at 210" F., and a viscosity index of about 130. Whenfthe foregoing. run wasrepeated, but with the addition of 2 parts "of chloro form as catalyst, the yield of heavy oil of 0" pour point was increased to 51.4 parts. In each of these reactions, there was recovered approximately 29 parts of unreacted ethylene. V

The runs described in the preceding paragraph were thenrep'eate d, using 2-hour and 4-hour reaction periods, respectively. Witlf tlie use of chloroform 'catalySt' the amount of heavy oil recovered was 60 and 85.5 parts at 2 and 4 hours respectively, while in the uncatalyzed runs the increasein the yield of heavy oil was such as to yield 34.4 parts and 42.4 parts as reaction periods of 2 and 4 hours were employed. 7 V V Again repeating the forcgoing runs with catalyst, but at 620 F., itwas found that the 2- and 4-hour reaction periods resulted in the production of 41 and 53.6 parts, respectively," of heavy dilof 0 F. pour point.

EXAMPLE 8 This operation was conducted by employing thezsame reaction conditions as described in thefirst paragraph action period to 4 hours had the effect of increasing the yield of heavy oil to about 26 parts (in the absence of catalyst) and to about 45 parts with the employment of 2.4 parts of chloroform catalyst.

EXAMPLE 9 In this example eicosane was subjected to reaction first alone and then in the'presence of ethane and chloroform The first reaction involved heating 100 parts of eicosane, in a suitable pressure vessel, to 662 F. and maintaining the contents of the vessel at that temperature for 5 hours. On distilling the resulting product in vacuo to obtain a light oil fraction, and then solvent dewaxing the higher boiling materials at F., there was obtained a total of but 7.2 parts of both light oil and the heavier 0 F. pour point material. Since the eicosane starting material (which was of commercial grade) contained 6 parts of 0 F. pour point oil, this is evidence that substantially no reaction occurred during the heating of the eicosane.

To determine whether the presence of a catalyst would have any effect-on the reactivity of eicosane in the absence of any olefinic reactant, though under elevated pressure conditions, 300 parts of commercial eicosane were heated to 660 F. At this point the pressure vessel was charged with 134 parts of ethane and 6 parts of chloro-.

.form. The .vessel, at an initial pressure of 2100 p. s. i. g.,

was now heatedfor 2 hours at 660 F. At the end of this time the pressure in the vessel was still 2100 p. s. i. g. The liquid product was then worked up by topping oif a small amount of a light oil and by then solvent dewaxing.

the residue at -20 F. Here again, however, as in the operation described in the preceding paragraph, the total amount of light and heavy oils recovered did not appreciably exceed that contained in the eicosane starting material.

' EXAMPLE 10 This operation was conducted to compare the eflicacy of a number of different catalysts. The procedure employed with each catalyst was to react 300 parts of commercial eicosane with approximately 150 parts of ethylene at a temperature of about 670 F. for a period of 4 hours. The resulting liquid reaction mixtures were treated by topping to remove the lighter oil fraction boiling below about 250 F. at 1 mm. Hg and by then solvent dewaxing the residue at '-20 F. to determine the amount of 0 F. pour point oil produced during the reaction. In the table below, which lists the catalyst employed, the amount of 0F. pour point oil is expressed in terms of parts per 100 parts of the eicosane starting material employed.

Table I I Amt. of 0 F.

Catalyst Pour Point Z1101: (7 parts)-.. BF; (7 parts)..--

300 parts of wax (M.P.=125-130 F., M. W.=375), 300 parts of 2-butene and 6 parts of chloroform were Oil Produced 12 a charged to a bomb. The bomb was heated to about 670 F. over a period of 5 hours and held at this temperature for an additional period of 8 hours. A yield of 465 parts of liquid product was obtained which after distillation to remove light overhead left 443 parts of heavy oil boiling above 365 F. at 4 mm. of mercury pressure. This oil was dewaxed at 55 F. using methyl isobutyl ketone as a solvent yielding 88 parts of oil having the following properties:

Viscosity, centistokes:

0 F 662.5 100 F 19.6 130F 11.34 210 F 4.06 Viscosity index 122 Pour point, F. -20

EXAMPLE 12 814 parts Minas crude oil,'425 parts ethylene and 19 parts chloroform were charged to a bomb and heated at a temperature of about 650 F. for 10 hours.

A yield of 993.6 parts of liquid product was obtained after reaction. A comparison of the properties of this liquid with those of the original crude oil are as follows:

Original I Treated Property Crude Crude Gravity, API 35.8 37.2 Pour Point, F +.5 Below -60 Fraction boiling above 430 F. at 1 mm. Hg:

Oil, percent 17.6 26.2 Wax, percent 20.2 i .8 Asphaltenes, percent 2.0 0. 2 Resins, percent. 8. 4 5. 9

These data show that the lubricating oil content was 'materially increased by the treatment with ethylene at the expense of the wax, asphaltenes and resins.

A comparison of the properties of the lubricating oil before and after treatment follows:

Original 7 Treated Crude Crude Viscosity at 100 F. ssU 1110 955. 4 Viscosity at 210 F. SSU.. 82.1 86. 0 Viscosity Index V 68 EXAMPLE 13 In many cases it is advantageous to remove the un- Hydro- Unhydro- Properties genated Oil genated Oil Gravity, API 38. 3 38.1 Bromine Number.... 2 12 Pour Point, F 20 10 Viscosity. eentistokes:

210 F 4.6 4.7 130 F... 12.8 13.1 22. 2 22. 6 Viscosity Index 143 '15 Induction Period, Hours 3. 3 2. 2

1 Both oils compounded with 0.1% phenyl-a-naphthylamine. and the induction period, a criterion of oxidative stability, determined in accordance with the procedure and apparatus describedinIndustrial and Engineering Chemistry, vol. 28, p. 26 (1936).

13 EXAMPLE 14 Gravity, API 38.9 Bromine number 17 Molecular weight 360 Viscosity, centistokes:

100 F. 13.68 130 F. 8.27 210 F. 3.23 Viscosity index 115 EXAMPLE 15 To a bomb there were charged 554 parts of cetane, 425 parts of ethylene and 23 parts of chloroform. The bomb was heated to a temperature of about 650 F, over a period of 8 hours and then kept at a temperature of about 640 F. for 8 hours. After reaction, 910 parts of liquid reaction products were obtained. This mixture was distilled to a temperature of about 270 F. at 2.7 mm. of mercury pressure to remove unreacted ceta'ne. A yield of 639 parts of product boiling above cetane was then isolated. This liquid was subjected to dewaxing at -50 F. using methyl isobutyl ketone as the solvent. The yield of dewaxed oil was 248 parts. The oil had a molecular weight of 305, and a pour point of 45 F.

While the oils of the present invention find particular utility as crankcase lubricants in automotive and other types of internal combustion engines, they are also useful as torque or power transmitting fluids and as lubricants for many specialized applications, including the lubrication of gas turbines, gears, and aircraft engines. The lubricating oils of this invention may also be used advantageously as base oils for grease compositions. That is, the oils herein may be thickened to the consistency of greases by incorporating therein such thickening agents as metal soaps (e. g., calcium stearate, lithium hydroxy stearate, etc.), polymers of ethylene (i. e., linear solid ethylene polymers), inorganic aerogels (e. g., silica, thoria, etc.), polymeric nitrogen-containing compounds (e. g., polyamides obtained from amines and dibasic acids), and the like.

The utility of the present oils for many of the above purposes, particularly those relating to the use of said oils as gas turbine lubricants or as aviation oils or greases, is largely attributable to the fact that the slope of the viscosity curve of these oils decreases, or takes a downward turn, at lower temperatures, notably those which are well below F. Thus, an oil derived by reacting eicosane with ethylene and which has a viscosity of 2.85 centistokes at 210 F. and of 11 centistokes at 100 F. and would, by extrapolation, be calculated to have a viscosity of 10,000 centistokes at 65 F., actually proves to have a viscosity of but 7,600 centistokes at 65" F.

Unless otherwise indicated herein, the parts or percentages given are on a weight basis.

We claim:

1. In a process for converting a normally solid hydrocarbon wax to a lubricating oil, the steps comprising reacting said wax with an olefin of from 2 to carbon atoms in the presence of a hydrocarbyl halide catalyst at a temperature between 400 and 700 F. and at a pressure between and 15,000 p. i. g.; and separating from the resulting reaction mixture the constituents boiling below 250 F. at 1 mm. Hg as well as the unreacted wax; the residual oil obtained in this fashion being characterized by a viscosity index of at least 100 and by a pour point not greater than about 10 F.

2. A lubricating oil produced by the method of claim 1.

3. The process of claim 1, wherein the olefin reactant is ethylene and the catalyst is an alkyl halide.

4. The process of claim 1, wherein the wax reactant is a hydrocarbon of predominantly open-chain configuration which contains from about 15 to 100 carbon atoms in the molecule, the olefin reactant is ethylene, and the catalyst is an alkyl halide.

5. In a process for converting a normally solid hydrocarbon wax to a lubricating oil, the steps comprising bringing said wax into reactive engagement with ethylene in the presence of a chloroform catalyst at superatmospheric pressure and at a temperature between 600 and 700 F., said reactants being employed in the proportion of from 1 to 25 moles of ethylene per mole of wax; distilling the lighter ends from the resulting reaction mixture; and treating the remaining heavy residue to remove unreacted wax therefrom; the resulting liquid oil product being characterized by a viscosity index of at least 100 and by a pour point not greater than about 10 F.

6. The process of claim 5 wherein the wax reactant is a parafiinic hydrocarbon containing from about 20 to 40 carbon atoms in the molecule.

7. The process of claim 5 wherein the Wax reactant is eicosane.

8. In a process for producing a lubricating oil, the steps comprising reacting at least one normally gaseous olefin with a mixture of paraifin waxes of petroleum origin in the presence of an alkyl halide catalyst, said reaction being conducted at a temperature between about 600 and about 700 F. and at a superatmospheric pressure, and said reactants being employed in the ratio of from about 1 to 25 moles of the olefin for each mole of wax; and then isolating from the reaction mixture so obtained a lubricating oil having a viscosity index of at least 100 and a pour point not greater than about 10 F.

9. A lubricating oil produced by the method of claim 8.

10. The process of claim 8 wherein the olefin reactant is comprised predominantly of ethylene.

11. The process of claim 10, wherein the catalyst is chloroform.

12. The process of claim 10, wherein the catalyst is methylene chloride.

13. In a method for lowering the pour point of a waxbearing material selected from the group consisting of waxbearing crude oils, distillation and lubricating oils, the steps comprising reacting said wax-bearing material with at least one olefin of from 2 to 10 carbon atoms in the presence of an alkyl halide catalyst, said reactants being employed in the ratio of from 1 to 25 moles of said olefin for each mole of wax present in the waxy starting material, and said reaction being conducted at a temperature between 400 and 700 F. and under superatmospheric pressure.

14. The product produced by the method of claim 13.

References Cited in the file of this patent UNITED STATES PATENTS 2,063,623 Pier et a1. Dec. 8, 1936 2,410,107 Sachanen et a1. Oct. 29, 1946

Claims

1. IN A PROCESS FOR CONVERTING A NORMALLY SOLID HYDROCARBON WAX TO A LUBRICATING OIL, THE STEPS COMPRISING REACTING SAID WAX WITH AN OLEFIN OF FROM 2. TO 10 CARBON ATOMS IN THE PRESENCE OF A HYDROCARBYL HALIDE CATALYST AT A TEMPERATURE BETWEEN 400 AND 700* F. AND AT A PRESSURE BETWEEN 100 AND 15,000 P. S. I. G,; AND SEPARATING FROM