US2410381A - Lubricating oil composition - Google Patents

Description

Patented Oct. 29, 1946 LUBRICATING OIL COMPOSITION Vance N. Jenkins, Palos Verdes Estates, Calif., as-

signor to Union Oil Company of California, Los Angeles, Calif., a corporation of California No Drawing. Application September 22, 1943, Serial No. 503,449

2 Claims.

This invention relates to synthetically produced high viscosity lubricating oils or lubricating oil blending agents, to processes for producing the same from paraffin waxes and the like, and to lubricating oil compositions containing these synthetically produced lubricating oils or lubricating oil blending agents as apart of their composition.

United States Patent No. 2,082,203, to Gardiner et al., "describes a process for producing synthetic lubricating oils involving the following steps: (1') dehydrogenation of a "paraffin wax by chlorination, (2) separation of the unchlorinated Wax by cooling to crystallize the wax and centrifuging the crystallized unchlor-inated wax from the chlorinated Wax, (3) dechlorination of the chlorinated wax with simultaneous polymerization in the presence of a catalyst, such as aluminum or aluminum amalgam. While this process resulted in the production-of a lubricating oil of high viscosity index, the viscosity of the oil was generally below 110 seconds Saybolt Universal at 210 F.

It is an object of my invention to produce a synthetic lubricating oil or lubricating oil 'blending agent having a viscosity above 300 seconds and preferably above 3,000 seconds Saybolt Universal at 210 F. and at the same time possessing a high viscosity index.

Another object of my invention is to produce a synthetic lubricating oil or lubricating oil blending agent having ahigh'viscosity and a high viscosity index, which is more'resistant to oxidation than a naturally occurringoi-l of the same viscosity, which upon oxidation does not result in the formation'of sludgeor asphaltic bodies and which is not rubbery at high viscosities.

Another object of my invention is to produce a lubricating oil-composition comprising a mineral lubricating oil and a synthetically produced lubricating oil blending agent, said lubricating oil composition having a'higher viscosity index than is obtainable by blending naturally occurring mineral lubricating oils of similar viscosities.

Other objects, features and advantages of my invention will be apparent from the following description:

In general, the essential steps for producing lubricating oil compositions containing synthetic v lubricating oils or lubricating oil blending agents atively low viscosity fractions from the polymerization product and (5) blending the dewaxed polymerization product with mineral lubricating oil.-

The chlorination of parafiin wax is carried out in a conventional manner by direct contact of the paraffin wax with chlorine at temperatures above about F; and preferably below about 250 F, in the absence of catalysts, although catalysts may be used to increase the chlorination rate thereby decreasing the reaction time. The chlorination of the paraffin Wax is continued until the desired amount of chlorine is absorbed in the hydrocarbons, and has reacted with the hydrocarbons, resulting in the production of chloroparaffins. Generally, the chlorination is continued until a mixture is produced containing about 10% to 20% by weight of chlorine based on the total weight of the product resulting from the chlorination, although the degree of chlorination will depend upon the average molecular weight of the wax and the degree of unsaturation desired in the wax olefins which are later produced from said chlorinated paraffin Wax by dechlorination.

The dechlorination of the products resulting from the chlorination step is preferably accomplished by heating the chlorinated product to a temperature in the neighborhood of 400 F. to 600 F. which results in the evolution of hydrogen chloride gas. During the dechlorination step, care is taken to prevent polymerization and/or isomerization from taking place, thus preserving the carbon skeleton of the wax molecules. Preferably, the dechlorination is carried out in the absence of catalysts which may effect polymerization or isomerization at the dechlorination temperature. However, it is desirable to carry out the dechlorination step in the presence of alkaline binding agents for hydrochloric acid, such as calcium or magnesium oxides or the corresponding hydroxides and also the alkali metal oxides and hydroxides. The amount of the binding agent used should :be sufficient to bind all of the hydrochloric acid, hence stoichiometric amounts of the binding agent should be used. The use of the binding agent results in the production of a lighter colored product and greatly reduces the corrosion'of the apparatus in which the dechlorination is effected. The dechlorination is carried out for a sulficient period of time to permit substantially complete dechlorination of the chloropa-rafiins since the presence of moderate amounts of chloroparaifins during the subsequent polymerization step results in the formation of an insolublesludge in the polymerized oil due to liberation-of anhydrous hydrogen chloride which it is believed, reacts in the presence of the polymerizing catalyst to produce isomerized products of lower viscosity index.

Polymerization of the wax olefins obtained by dechlorination is effected by heating the product in the presence of a catalyst, .such -as anhydrous aluminum chloride at a lower temperature than that employed in the dechlorination step, the polymerization temperatures being preferably in the range of from about atmospheric temperature to about 200 F., said temperatures being below those at which cracking or decomposition of the wax olefins or the resulting poly-' mers would take place. The point of heating at which cracking or dissociation of the wax olefins and/or resulting polymers takes place may be evidenced by the evolution of hydrogen chloride, a product resulting from the decomposition of the catalyst and reaction with the olefins or polymer. Hence, the polymerization reaction is carried out below a temperature at which substantial quantities of hydrogen chloride are evolved. The polymerization is preferably carried out in the presence of about 2% to about by :Weight of anhydrous aluminum chloride depending upon the reaction time and completeness of reaction desired. Other halogen compounds may. be employed as catalysts, such as anhydrous hydrogen fluoride, boron trifluoride, stannic chloride, etc. The polymerization reaction may be carried out in the'presence of an inert solvent, such as a parafiinic or naphthenic light hydrocarbon fractioncontaining pentane, cyclopentane, hexane, cyclohexane, or mixtures of these and related compounds, which reduces the viscosity of the mass sufficiently to permit easy stirring and consequently more eflicient heat transfer. The use of the solvent is not accompanied by a separation of a sludge layer since no sludge is formed in carrying out the above described process.

In order to remove the aluminum chloride or other catalyst employed for the polymerization step, the'reaction mass, with or without a diluent whichmay be used as indicated above to reduce the viscosity, is hydrolyzed with water or dilute sulfuric i or hydrochloric acid solutions. The hydrolyzing agents dissolve the aluminum chloride and the aqueous solutions produced are separated from the polymers by decantation. The last traces of aluminum chloride are removed by washing with hot water, or preferably with a slightly alkaline aqueous solution, such as a very dilute aqueous solution of sodium hydroxide.

The polymerization product resulting from the above chlorination,dechlorination and polymerization steps comprises a mixture of unreacted paraflfin Wax, unpolymerized wax olefins, unreacte'd oil '(if the paraffin wax was not entirely oil-free) and polymerized wax olefins, the latter representing various stages of polymerization. Thus there may be present the wax olefin dimers, trimers, tetramers, and even higher polymers depending upon the conditions under which polymerization was effected and also upon the degree of chlorination of the paraffin wax and the resulting degree of unsaturation of the wax olefins. I'have discovered that solvent extraction of the above described mixture of products which constitutes the polymerization product with a normally gaseous hydrocarbon having more than two carbon atoms and less than five carbon atoms permolecule at temperatures in the range of about 40 F. to about 185 F. or higher and under pressures which are great enough to maintain,

an insoluble or reject phase. may be separated from the polymers by ordinary 4 said hydrocarbon in the liquid phase, it is possible to separate the unchanged or unreacted paraffin wax, the unpolymerized wax olefins and other low molecular weight and/or low viscosity fractions from the higher molecular weight, higher-viscosity, ipolymerized; products; The unchanged wax and the low viscosity fractions are soluble in and are selectively dissolved and removed by the solvent while the wax olefin polymers are insoluble in the solvent and remain as The solvent phase decantation methods. The removal of both the -unreacte'd waxandthe unpolymerized wax olefins is highly important since the presence of either or'both of the'materials results in increasing the pour point of the polymeric oil and also results in increasing the pour point of lubricating oils obtained directly from petroleum by the usual refining methods when said lubricating oils areblended with the said polymeric oils con-- taining said unreacted wax and/ or unpolymerized wax olefins.

- In the foregoing solvent extraction process the treatment may be carried out as a batch process in which the polymerized product'is thoroughly mixed with appropriate proportions of a solvent, such as propane, allowed to separate into two phases, and then the upper or solvent phase is removed by decantation, leaving the treated polymeric oil as an insoluble residue This residue, which consists of the polymerized wax olefins and which is further described as a high viscosity lubricating oil or lubricating oil blending agent may be freed from solvent by heating to temperatures in the'range of about 200 F. to about 300 F. r Y

It is within the scope of my invention to carry out the separation of unreacted wax, wax olefins and other low viscosity fractions from the desired high viscosity polymeric fractions by extraction with a solvent which will produce the desired separation by means of processes commonly described as (l) multiple-ba tch'extraction, in which portions of the total solvent to be used are applied in-two or more stages with mixing and phase separation being effected at each stage; (2) batch countercurrent extraction, which may consist of two or more stages, in which the fresh solvent is applied to the partially extracted polymeric oil in ,the'final stage, the once used solvent being transferred to the next preceding stage where it is, mixed with a less highly extracted polymeric oil from a preceding stage and allowed to separate, and so forth, until finally the solvent phase from the second stage is used to extract the fresh polymerization-product entering the first stage of the extraction process; (3) continuous countercurrent extraction, in which the polymerization product enters an extraction column at a point near the top of said column and flows countercurrent to the solvent which enters the same column at a point near its base, the extracted high viscosity lubricating oil fraction leaving the column at the bottom and the solvent containing dissolved wax and low viscosity fractions, or solvent phase, leaving the column at the top.

operate the several stages of a multiple batch or batch countercurrent treating processat diflerent temperatures in order to improve the selectivity of the solvent for the waxes and other low molecular weight fractions. For example, in a three Stage batch countercurrent treatment in It is also within the scope of my invention to which the polymerized-product enters "the first stage and fresh :solvent .enters the third stage 'I find-thatthe yields of extracted polymeric oilare improved and/or the viscosity of this .product is increased over that obtained when all stages are operated .at the same temperature if the :three stages are :maintained at graded temperature :levels. For example, .the first gstageimay be :maintained .at temperatures between about 185 F. and 190,F., the second stagebetweenabout .160" Rand 175 F., andthe third stage between about 14.5l ..and 160 A "further improvement .in the yieldand/or viscosity of the polymeric oiliis realized if, for example, .a so-called temperature rejection stage .is added to the above three-stage treater unit, saidstage which is placed above or before the first stage'being maintained at a temperature of. about F. ;to.about F. above that of the first stage.

.A further modification of the above described batch countercurrent .extraction process which I have :found will increase theviscosity of the extracted polymeric oil is to re-extract the said extracted polymeric oil in asepara'te stage with a solvent containing in addition to the propane, normal butane, isobutane, or mixtures of these compounds about 5% to 15% by volume of a higher molecular weight .hydrocarbonor hydrocarbon fraction, such as one of the pentanes, hexanes, heptanes or the like or a low boiling naphthafraction.

Furthermore, it .is within the scope of my invention to extract the polymerization product from the above process involvin chlorination, dechlorination and polymerization, with a selective solvent such as phenol, furfural, .nitrobenzene, liquid sulfur dioxide, or the like, for the purpose of separating and/or removing b-y solution in the said elective solvent the more olefinic fractions, i. e., those molecules having the greatest number-cf unsaturated or olefinic groups per molecule and those molecules otherwise having the highest ratio of unsaturated groups to total carbon atoms i .the molecule and leaving as :an

insoluble phase the higher molecularweightlpo'lymers and the unchanged wax. The insoluble phase from this operation :may be subsequently extracted with a solvent, such as propane in the manner described above for the removal of the unreacted parafiln wax and other low molecular weight fractions.

In the foregoing process I have found it to be extremely important to carryout the-dechlorination step without efiecting substantial polymerization and/orisomerization. The resulting polymer-free wax olefins may then be polymerized separately in the presence of anhydrous aluminum chloride without causing the formation of any or substantial amounts of sludge. In this connection it has been found by previous investigators that when dechlorination of a chlorinated paraffin wax is carried out in the presence of a polymerization catalyst such as anhydrous aluminum chloride, substantial quantities of insoluble sludge are produced and while the sludge may be hydrolyzed to produce a lubricating oil blending agent, this material is inferior in quality to that which has not been associated with aluminum chloride in the form of an insoluble sludge. chlorinating step in the absence of polymerization catalysts and under such conditions as to prevent polymerization andto preserve the chemical skeleton of the original waxmolecule.

While the dechlorination step may be followed I prefer, therefore, to carry out the .de-

directly by polymerization it is rdesirable, at :least in some instances, to subject the dechlorinated products, :consisting of a mixture of wax olefins and unreacted paraflin wax together with small proportions of polymerized wax olefins, to a treatment designed to remove completely any polymerized materials which may be present as a result of polymerization during the dechlorination step. This separation may be effected by distillation by means of whichthe unreacted wax and wax ,olefins are obtained as an overhead fraction and the polymerized materials are obtained as .a distillation bottoms. The distillation is preferably accomplished under a pressure of about to mm. of mercury at a vapor temperature of about 500 to 700 F., employing steam to aid in stripping the bottomsiraction.

Separation of the unpolymerized wax colefins from the polymerized wax olefins may also be eifected by processes involving solvent extraction.

. Thus I have discovered that the declorination product may be extracted with .a .solvent, such as propane,.norma1 butane, isobutane or mixtures thereof, at temperatures in the order of \from 40 F. to 150 F., using batch, multiple batch, batch countercurrent, or -;continuous 'coun'tercurrent methods of treatment 'to'separate effectively from the desirable wax olefin 'fractioncontaining unreacted wax the undesirable polymerized olefins, the latter materials being insoluble in this solvent within-this temperature range. Either of the two above described treating procedures .results in the production of a polymer-free olefin fraction which may be subsequently polymerized in the presence of anhydrous aluminum chloride without the production of sludge.

As a modification of the above described processes the dechlorinated or-wax olefin product may be extracted with a'selec'tive solvent, such as phen01, furfuryl, nitrobenzene, liquidsulfur dioxide, or the like, under such conditions that the wax olefins are dissolyed b-yzthe said selective solvent and removed as an extract phase leaving the greater proportionofthe unchanged'paraifin wax and high molecular weight polymers as a reject or raffinate phase. The wax olefins, after removal of the solvent, may then be polymerized without the application of such further treatments as distillation or solvent extraction using propane, etc.

The raw material which may be used in my process may consist of refined relatively high. melting point 'paraflin Waxes or crude scale waxes of about F. to F. melting point or lower melting point waxes such as those melting at about .l00 F. to 110 F. I have also found that the low melting oint waxes, such as those recovered from foots oil, may also be used. Foots oil is the relatively valueless by-product resulting :from the refining of slack wax produced in the dewaxing-of lubricating oils in the production of high melting point wax. The foots oil may be obtained from the sweating operation of slack wax or it may be obtained by crystallizing the slack wax and filtering it to separate the high melting wax from the foots oil. The latter method may be accomplished in the'presence of diluent to the slack either before, during or after chilling of the slack wax. The low melting point waxes may then be removed from the icots oil by dissolving the facts oil in several volumes of a suitable diluent, such as methyl ethyl ketone, :aceton'e, propane, butane, -etc., then chilling the solution to crystallize the wax fol lowed by filtering, centrifuging or .cold settling of the chilled solution, to separate a solution of diluent and oil from the crystalline wax;

Preferably, the wax to be chlorinated should not contain more than about of oil since the presence of oil has been found to increase the proportion of heavy polymerized material obtained upon distillation or solvent extraction of the wax olefins produced in the dechlorination step. .The presence of appreciable amounts of oil in the wax also tends to lower the quality of the polymer and to produce some oil insoluble sludge during the polymerization step. Hence, if the original wax contains more than about 5% of oil, it is desirable to distill the wax olefins overhead prior to polymerization or to extract the deohlorinated product with a solvent in order to eliminate the undesirable polymers. In those cases in which the original wax is substantially free from oil, the distillation or extraction prior to polymerization is generally unnecessary because the polymerization of the wax olefins produced from such oil-free waxes will not result in the formation of undesirable sludge.

The viscosity of my synthetic lubricating oil additive may be controlled in various ways. In general the greater the percentage of chlorine present in the chlorinated parafiin wax the higher will be the viscosity of the blending agent prepared therefrom. Also, the greater the amount of polymerization occurring during the polymerization step the higher will be the viscosity of the finished blending agent. Furthermore, the method of effecting the solvent extraction of the polymerization process is reflected in the viscosity of the finished blending agent. As the efficiency of the solvent extraction increases the viscosity of the blending agent increases.

Thus I may vary the viscosity of my synthetic blending agent by varying one or more of the above described processes and I may produce blending agents having viscosities as low as about 300 seconds Saybolt Universalat 210 F. although I prefer to produce a material having a viscosity above 3,000 seconds Saybolt Universal at 210 F. and I find that products having Saybolt Universal viscosities above about 10,000 seconds at 210 F. are particularly valuable.

Lubricating oil compositions having high viscosities and/or high viscosity indices may be prepared by blending mineral lubricating oils with the synthetic lubricating oils or lubricating oil blending agents produced by any of the above described processes. The improvement in viscosity and viscosity index of the mineral lubricating oil by the addition of my synthetic lubricating oil blending agent is greater than that obtained by the addition of similar amounts of ordinary lubricating oils having the same viscosities as the synthetic agent. Blending may be accomplished by merely agitating the lubricating oil with the synthetic blending agent at ordinary temperatures, however, it is preferable to heat and agitate the mixture at about 300 F. until a homogeneous product is obtained. The synthetic blending agent is miscible in all proportions with mineral lubricating oil and shows no tendency to separate from solution after use or after long periods of standing. I may use all types of mineral lubricating oils because blends comprising the synthetic blending agent and all types of mineral lubricating oils exhibit the desired characteristics of improved viscosity index, higher viscosity and stability. Thus I may use low viscosity index acid refined Western or naphthenic lubricating. oils, or the higher viscosity index lubricating oils such as highly solvent refined Western lubricating oils or Eastern lubricating oils, such as Pennsylvania lubricating oils.

In preparing lubricating oil compositions containing the synthetic lubricating oil blending agent I may use any desired proportion of said blending agent. Thus I may use the synthetic blending agent alone, i. e., without the addition of mineral lubricating oil thereto, as the lubricating oil composition, although generally I prefer to combine the blending agent with mineral lubricating oil. The proportion of the blending agent to be used will depend upon the desired viscosity and/or viscosity index of the lubricating oil composition to be produced and on the viscosity and/or viscosity index of the mineral lubricating oil and the synthetic blending agent to be employed and I may use any proportion of said blending agent. Thus, lubricating oil compositions prepared in accordance with the principles of my invention may contain from about 1% to about 75% by weight or even higher of the synthetic blending agent and correspondingly from about 99% to about 25% by weight of a mineral lubricating oil.

The following specific examples serve to further illustrate the invention but are not to be taken as in any way limiting the invention.

Example I A batch of match wax of F. to 112 F. melting point was chlorinated to give a total chlorine content of 17% by weight of the chlorination product. The chlorination was carried out at a temperature in the range of F. to F. To 15,436 grams of the chlorinated paraffin Wax was added 3,859 grams of hydrated lime, Ca.(OI-I)2. Dechlorination of this mixture was effected by placing the mixture in a closed vessel arranged with a mechanical agitator and an outlet to allow escape of vapors and arranged for heating by means of direct fire, where it ws heated gradually with agitation to a temperature of 550 F. over a period of five hours and maintained at 550 F. ,for an additional fifteen minutes. The mixture was then cooled to atmospheric temperature, filtered through a large Biichner funnel which had been precoated with clay, such as Flter-Cel, and finally the filter cake washed with naphtha. The naphtha washings were added to the filtered dechlorination product. The naphtha was removed by a topping distillation which was carried out at a pressure of 25 mm. mercury and a bottoms temperature up to 450 F. There was obtained 9,761 grams of a dechlorinated product.

In order to prepare this dechlorinated product for polymerization, 9,534 grams of the olefin fraction was distilled at a pressure of 2.5 mm. mercury to a vapor temperature of 725 F. There was obtained as an overhead fraction 8,535 grams of a mixture of wax olefins containing unreacted parafiin wax.

The thus prepared wax olefin fraction was polymerized in the following manner: To 4540 grams of the olefin fraction was added 272.4 grams of C. P. anhydrous aluminum chloride, the addition being carried out in three steps. One-third of the aluminum chloride to be used, or 90.8 grams, was added and the mixture was agitated for ten minutes at which time a second 90.8 gram increment was added and the third 90.8 gram increment was added after an additional one-half hour. The final mixture was agitated for a total of twenty hours and during this period the temperature was maintained at and thoroughly washed with. fresh: portions of water to remove substantially all of the aluminum: chloride leaving "the crude polymer- T0715 grams of the thus prepared'crude polymercontained in, a closed pressure vessel: was added 3500 ml. of propane. The mixture washeated'to 170 F. and agitatedin order-to. obtain good contact withthe solvent;v The mixture was, then allowed to separate" into two. phases, the

upper or solvent phase being. removed by decantation and thelower 'or-reject' phase then being-withdrawn from the closed vessel and heated to a temperature of 250' Rto remove the propane. The solvent-free reject. phase which amountedto 393 grams, or: 5.5% by weight of the crude polymer, had a Saybolt Universal? viscosity of 4868.3 seconds at 210 F."

A 275 gram portion of the reject from the preceding. propane. extraction, which will be referred to as polymeric oil A, was re-extracted in the same manner with 1500 ml. of propane at 155 F. The reject phase from this operation after removal of propane amounted to 225 grams, corresponding to a yield of 45% by weight of the original crude polymer. This insoluble fraction, polymeric oil 13, had a Saybolt Universal viscosity of 11,774 seconds at 210 F., a non-rubbery texture and was completely soluble in mineral oils and also in petroleum naphtha.

High viscosity lubricating oils were prepared by blending polymeric oils A and B with an S. A. E. 20 grade parafiinic lubricating oil having a Saybolt Universal viscosity of 51.9 seconds at 210 E, a viscosity index of 90, a viscosity gravity constant of 0.812 and a pour point of 20 F. In each instance the blending was accomplished by agitating and heating the mixture to a temperature of about 300 F.

A blend containing equal parts by weight of polymeric oil A and the above mentioned S. A. E. 20 lubricating oil had a Saybolt Universal viscosity of 597.8 seconds at 210 F., a viscosity index of 123 and a pour point of 30 F. The calculated viscosity of this blend was only about 250 seconds Saybolt Universal at 210 F. when obtained from the usual lubricating oil viscosity blending charts.

A second blend containing equal parts by Weight of polymeric oil B and the S. A. E. 20 lubricating oil had a Saybolt Universal viscosity of 905.7 seconds at 210 F., a viscosity index of 122 and a pour point of 25 F.

A third blend containing 15% by weight of polymeric oil B and 85% by weight of the same S. A. E. 20 lubricatingoil as used in the two preceding blends was prepared and treated with 3% by weight of a lubricating oil treating clay at 330 F. The treated and filtered product had Saybolt Universal viscosities of 989.1 seconds at 100 F. and 103.8 seconds at 210 F., a viscosity index of 118 and a pour point of F.

Two lubricating oils were prepared using polymeric oil B and a naphthenic lubricating oil having Saybolt Universal viscosities of 1344 seconds at 100 F. and 75.1 seconds at 210 F. and a viscosity index of 8. The first blend contained 5% by weight of polymeric oil B and 95% by weight of the naphthenic lubricating oil and had Saybolt Universal viscosities of 1934 seconds at 100 1 0. F., and 100 seconds at 210 F. and a viscosity index of 49.

' The second blend contained 10%. by weight of. polymeric oil B and.9'0% by weight of the naphthenic, lubricating oil; This blend had Saybolt Universal viscosities of 2831 seconds a t-100 F. and 139.0 seconds at 210F. and a viscosity index of 75.

Example II To 2120 grams of crude polymer produced as described in Example I, which was placed in a. closed pressure vessel, was added 12,500'm1. of propane. The mixture was heated to 126 F. and agitated in order to obtain good. contact between the polymer andthe propane. Themixture-wasallowed to separate into two, phases, the upper or solvent phase being removed by decantation; A second 7,500 ml. portion of. propane was then added to and mixed with the reject or insoluble phase from the first operation contained in the: closed vessel and allowed to settle. This-second extraction was. carried out at atemperature. of 126 F; The solvent phase wasdecanted-iandthereject phase was withdrawn from the closed Vessel and heated to a temperature of 250 F. to remove the propane. The depropanized reject phase which will be referred to hereinafter as polymeric oil C amounted to 725 grams or 35% by weight of the crude polymer.

High viscosity lubricating oils were prepared by blending polymeric oil C with various parafiinic lubricating oils. The blending operation, unless otherwise noted, consisted in agitating the mixture while heating to a temperature of 300 F.

The first blend consisted of equal parts by Weight of polymeric oil C and the 'S. A. E. 20 paraffinic lubricating oil described in Example I. This blend had a Saybolt Universal viscosity of 2431.6 seconds at 210 F. and a pour point of 25 F.

A second blend was-prepared containing 10% by weight of polymeric oil C and by weight of the above mentioned S. A. E. 20 lubricating oil. This blend had Saybolt Universal viscosities of 957.7 seconds at F. and 101.4 seconds at 210 F., a viscosity index of 117 and a pour point of 0 F.

A third blend was prepared containing 7.5% by weight of polymeric oil C and 92.5% by weight of a paraflinic S. A. E. 40 grade lubricating oil having Saybolt Universal viscosities of 719.3 seconds at 100 F. and 72.2 seconds at 210 F., a viscosity index of 89 and a pour point of 15 F. The resulting blend had Saybolt Universal viscosities of 1460.4 seconds at 100 F. and 124.4 seconds at 210 F., a viscosity index of 111 and a pour point of 10 F.

A fourth blend Was prepared containing 11% by weight of polymeric oil 0 and 89% by weight of a paraffinic S. A. E. 10 grade lubricating oil having Saybolt Universal viscosities of 179.4 seconds at 100 F., and 44.8 seconds at 210 F. and a viscosity index of 93. This blend was treated with 3% by weight of a lubricating oil treating clay at 325 F. and the treated and filtered product had Saybolt Universal viscosities of 609.4 seconds at 100 F., 83.5 seconds at 210 F., a viscosity index of 127 and a pour point of 20 F.

The foregoing description and examples are not to be taken as in any way limiting but merely as illustrative of my invention for many variations may be made by those skilled in the art without departing from the spirit or scope of the following claims.

I claim:

1. A synthetic lubricating oil blending agent having a viscosity above 10,000 seconds Saybolt Universal at 210 F., said lubricating oil blending agent being produced by chlorinating paraffin wax, dechlorinating said chlorinated paraffin wax at temperaturesbetween about 400 F. and 600 F. to cause dechlorination without efiecting substantial polymerization thereby producing wax olefins, distilling the wax olefins to remove therefrom polymerized material formed during the dechlorinating step, catalytically polymerizing the polymer-free wax olefins and subsequently extracting said polymerization product with a normallygaseous hydrocarbon solvent having more than two and less than five carbon atoms per molecule and having a high solvent power for paraflin wax and wax olefins and a low solvent power for said lubricating oil blending agent at the temperature of extraction to separate a solution of paraffin Wax and wax olefins in said solvent from said lubricating oil blending agent.

2. A lubricating oil composition comprising about 25% to about 99% by weight of a mineral lubricating oil and about 1% to about 75% by weight of a synthetic lubricating oil blending agent having a viscosity above about 10,000 seconds Saybolt Universal at 210 F., said lubricating oil blending agent being produced by chlorinating paraflin wax, dechlorinating said chlorinated paraffin wax at temperatures between about 400 F. and 600 F. to cause dechlorination without effecting substantial polymerization thereby 'producing wax olefins, distilling the wax olefins to remove therefrom polymerized material formed during the dechlorination step, catalytically polymerizing the polymer-free wax olefins and subsequently extracting said polymerization product with a normally gaseous hydrocarbon solvent having more than two and less than five carbon atoms per molecule and having a high solvent power for parafiin wax and wax olefins and a low solvent power for said lubricating oil blending agent at the temperature of extraction to separate a solution of paraflin wax and wax olefins in said solvent from said lubricating oil blending agent.

. VANCE N. JENKINS.