US2236897A - Lubricating oil - Google Patents

Description

Patented Apr. 1, 1941 LUBRICATING 01L Floyd L. Davis, Bert H. Lincoln, and Gordon D.

Okla, assignors to Conti- Byrkit, Ponca City,

nental Oil Company,

poration of Delaware No Drawing. Application April 18, 1940, Serial No. 330,370

13 Claims. 01. 252-45) Our invention relates to improved lubricating oils and more particularly to lubricating oils having exceptionally high viscosity indices.

This application is a continuation-in-part of our co-pending application, Serial No. 230,660,

filed September 19, 1938.

Two general methods of obtaining high viscosity example, lubricating oils have been prepared by the action of polymerizing reagents such as aluminum chloride, ferric chloride, phosphoric acid and phosphates, boron fluoride, and the like on lower olefins such as ethylene, propylene, butylenes, and higher olefins such as hexene, octene, and even cetene, CmHaz. Various mixed olefins have been polymerized such as cracked gases, cracked paraflin wax and the like.

Synthetic lubricating oils have been prepared by various condensation reactions. For example, the condensation of halogenated wax or other petroleum fractions with aromatic hydrocarbons or other aromatic compounds such as naphthalene, diphenyl ether and the like.

The products of our invention are more cheaply and easily made than other synthetic lubricating oils. They have higher viscosity indices than any previously reported. Furthermore, we utilize nonlubricating fractions of petroleum to produce these high qualitylubricating oils. Our products are, like the so-called white oils, extremely stable toward oxidation and sludging which is not true of ordinary lubricating oils. By our processes, we convert materials of low economic value into products of greatly enhanced value.

One object of our invention is to provide lubricating oils having extremely high viscosity indices.

Another object of our invention is to utilize non-lubricant petroleum fractions to produce improved lubricating oils. 1 A further object of our invention is to synthesize materials which may be used to improve the characteristics of ordinary lubricating oils.

A still further object of our invention is to convert materials of low economic value into Ponca City, Qkla', a corvaluable products by a. commercially feasible process.

Other objects of our invention will appear in the course of the following description.

Briefly our invention consists in the production of mixed cyclic and alkyl ethers of the type RXR' in which R is a high molecular weight, aliphatic radical having at least 13 carbon-atoms, such as may be obtained, for example, from paraffin wax and R. is an organic radical containing a carbocyclic or heterocyclic nucleus which may or may not bear various -alkyl or other substituting groups. It is necessary to have at least 13 carbon atoms in the aliphatic radical in order to obtain as products lubricating oils having visccsities of at least seconds Saybolt at 100 F. In the above formula, X stands for an atom of an element of the right hand side'of group VI of the periodic table, that is, oxygen, sulfur, selenium, or tellurium.

While ordinary lubricating oils have viscosity indices from as low as -40 for naphthenic oils to or for Pennsylvania'oils, the products of our invention have viscosity indices of not less than 90.

The aliphatic radicals of our products may be derived from any source and may be of various degrees of purity, that is, freedom from other types of radicals. For example, cetyl chloride is a suitable source of the cetyl radical. We may utilize paraffin hydrocarbonsof various petroleum fractions as sources of aliphatic radicals including hydrocarbons of the heavy ends of ordinary gasoline, kerosene, gas oil, paraffin wax and higher parafiin hydrocarbons from natural or synthetic sources. One preferred source of aliphatic radicals of the type described is a relatively pure monochlor paraffin wax, dichlor parafiin wax or the like.

In the prior art, references are made to monochloroparaffimdichloro paraffln,trichloro paraflin, and the like. It is usually considered that the product of direct chlorination is the compound represented by the total chlorine content and therefore the desired compound. We have found that these products of chlorination are very crude mixtures of the chlorinated hydrocarbons andcontain unchlorinated hydrocarbons and the mono-, di-,. and polychloro derivatives. The whole mixture cannot be considered the desired compound. For example, a so-called trichloro paraifin wax containing 24 per cent chlorine, which corresponds very closely to the percentage of chlorine in the trichloro compound, was separated by means of crystallization from acetone at low temperatures. The least soluble portion consisted of unchlorinated wax. The next least soluble portion consisted of a mixture of monochloro wax and unchlorinated wax. The percentage of unchlorinated wax in the original mixture, supposedly trichloro parafiln wax," was found to be 7.2 per cent. Thus, even a trichloro paraflin as so-called in the prior art, because of the total chlorine content, was in fact a crude mixture containing as much as 7.2 per cent of unchlorinated wax and quantities of mono- \and di-chloro waxes, as well as trichloro wax and more highly chlorinated waxes. Its use would not give the same results as a trichloro parailin free of higher and lower chlorinated paraflin, since the products will contain unhalogenated parafiln hydrocarbons and mixed derivatives. I

Even though the appropriate amount of chlorine is introduced in the Wax to form a monochloro wax, we have found that the crude chlorinaxtion mixture contains, in addition to small amounts of chlorine and hydrogen chloride and the desired monochlor wax, also unchlorinated wax and more highly chlorinated waxes. When dichlor and higher chlor wax is the desired product, the crude chlorination mixture will contain in addition to chlorine and.hydrogen, less highly chlorinated waxes.

In contrast to the use of of such a mixture, we have found it possible, as fully described below, to obtain a relatively pure monochlor compound free from unchlorinated hydrocarbon and free from more highly chlorinated compound. We may thus-prepare (1) monohalogenated hydrocarbons substantially free from unhalogenated hydrocarbons and more highly ialogenated hydrocarbons; (2) dihalogenated hydrocarbons sub-- stantially free from unhalogenated hydrocarbons and monohalogenated hydrocarbons, as well as from halogenated hydrocarbons containing more than two atoms of halogen per molecule; and (3) trihalogenated hydrocarbons free from halogenated hydrocarbons containing fewer or more than three halogen atoms per molecule and free them unhalogenated hydrocarbons. We refer in this specification to these materials as relatively pure waxes may be separated from each other by crys-,

monohalogen compounds, relatively pure dihalogen compounds, etc.

The chlorination of most petroleum hydrocarbons lowers their melting points and, up to a. certain point, the greater the extent of chlorination; that is, the more chlorine atoms per molecule, the lower the melting point. The decrease in meltin point. is stepwise, and this permits us to separate the unchlorinated hydrocarbons from the monochlorohydrocarbons and the monochloro hydrocarbons from the dichloro and higher chlorinated hydrocarbons. We can, for example, separate the unchlorinated wax from the :airblown mixture by filter pressing at such temperatures that all of the chlorinatedwaxes are largely liquids, while the unchlorinated waxe are largely solid. The

temperature for the pressing operation will depend, of course, on the character of the wax used 4 initially and will vary considerably depending on this factor. For example, at a temperature of from 80 F. to 90 F. the monochloro product formed by the chlorination of waxhaving a melting point of 120 F. will be liquid, while the unchlorinated wax will be solid, enabling a ready separation to be effected.

Other methods of separation, as for example,

sweating, selective solvent extraction at various temperatures, the use of diluents followed by chilling and settling or filtering, and the like,

rating the monochloro wax from the more highly chlorinated portions, and so on. In separating relatively pure monochlor, dichlor, etc., hydrocarbons from such sources as the heavy ends of gasoline, kerosene and the like, we preferably use chilling only as a method of separation since in solution extremely low temperatures are required. Solvents may be used here, of course, but it is more convenient to depend simply on difi'erences in melting point. It will be obvious to those skilled in the art that in these cases it is not practicable to employ diiferences in boiling point since the halogen derivatives of the lower hydrocarbons will have the same boiling range as un-' chlorination stepto obtain further quantities of chlorinated waxes. It does not represent refractory material, and the same proportions of chlorination products are obtained from it as from fresh wax.

The liquid chlorinated waxes after separation of unchlorinated hydrocarbons consist largely of monochloro and dichloro waxes when approximately 10 or 20 per cent chlorine respectively is introduced into a starting wax, of, say, from to F. melting point, but some polychloro wax may be present. These monoand dichloro tallization from acetone, using a solvent-chlor wax ratio of from 1 to 1 to 20 to 1. In preparing the solution, an elevated temperature may be employed to insure that the chloro waxes are completely dissolved in the solvent. The solution is then. chilled to a temperature of between minus 15 F. and minus 20 F. when a paraifin wax of 115 to 130 F. melting point is used for the initial chlorination; The monochloro waves are precipitated out nearly quantitatively, while the dichloro and polychloro waxes will remain in solution. The precipitated monochloro waxes may be readily separated by settling, filtering, or centrifuging.

We have also used other crystallization solvents such as methyl-ethyl ketone, acetone, benzene, methylene chloride, various other halogenated solvents as well as liquid propane or butane. Mixtures of two The use of a particular one or combination of these solvents requires the experimental determinaticn of the proper proportions and temperatures necessary to obtain the desired separation of the crude chlorination mixture into the various stages of chlorine contents. Halogenated solvents serve to aid in the precipitation of unchlorinated wax, while benzene and hydrocarbon solvents increase the solubility of the more highly chlorinated materials.

After removing the monochlor wax, the solution may be chilled to a lower temperature or concentrated by distillation or evaporation of the solvent or both to precipitate the dichlor waxes which may then be separated. A further separation of the remaining liquid may be accomplished by repetition of these processes. ner, the crude chlorination mixture may be separated into unchlorinated wax, monochlor wax, dichlor wax and polychlor wax. We proved the homogeneity of our monochlor wax, for example, by chilling until approximately half of the sample had solidified. Solid and liquid portions were separated from the I or more solvents may be used.

In this mantion is in progress, in order to'determlne the ex-- separated by a filtration and contained 12.1 and 11.4 per cent chlorine respective? y. In the case of the wax which had the 120 F. melting point, batches showed chlorine contents of 10.2, 19.3 and 10.5 per cent. These values are very close to the theoretical of 10.0 per cent. Thus, our

. tent oi chlorination as indicated above. Samples relatively pure monochlor wax is substantially free from unchlorinatedwax and more highly chlorinated waxes. We may prepare according to our invention similarly pure diand polychlor waxes free from unchlorinated wax and more highly chlorinated waxes.v

Our paramn hydrocarbons are preferably obtained from petroleum, though it is to be understood that any source rich in hydrocarbons ofthe paramn series may be used as starting materials in practicing our invention. Our method is particularly applicable to the higher parair'ln hydrocarbons such as represented by ordinary paraihn wax, but it is to be understood that it may be practiced on paraifinhydrocar bons of higher and lower molecular weight including all those parafiln hydrocarbons whose monochloro derivatives melt lower than the hydrocarbons themselves. While the product of the preferred embodiment of our invention is a mixture, the monochlor derivatives prepared according to our invention are free from unchlorinated and more highly chlorinated material. The dichloro derivatives are free from unchlorinated hydrocarbons, monochlorinated hydrocarbons, and more highly chlorinated hydrocarbons. The purity of the final product with respect to homologues is determined by the purity of the starting hydrocarbon. It is understood, of course,that when a pure hydrocarbon is employed, a correspondingly pure halide is obtained.

Having selected the hydrocarbon in accordance with the desired final product, we chlorinate the hydrocarbon until approximately that amount of chlorine is absorbed which will produce the monochloro compound when that is the desired prodnot, or approximately that amount of chlorine which will produce the dichloro compound when that is the desired product, etc.

In the case of paraffin hydrocarbons having from 18 to 24 carbon atoms per molecule, that is, a material having a melting point of approximately 120 F., about per cent added chlorine will produce substantially the equivalent of the monochlor product. The amount of chlorination may vary between 9 per cent and 12 per cent without being disadvantageous. The percentage of chlorine introduced into the hydrocarbon just described will be approximately 17 per cent when i a dichloro product is desired. The amount .of chlorine introduced will be less in the case of the high molecular weight, higher melting hydrocarbons, and more in the case of the lower molecular weight, lower melting hydrocarbons, for a given number of chlorine atoms per molecule. The chlorination may be accomplished in any suitable manner. -We prefer to heat the hydrocarbon to a temperature at least that of its melting point and pass chlorine gas through the absorbed.

may be removed from time to time, and the specific gravity of these be determined in order to follow the chlorination process. If desired, chlorineanalyses may be conducted on samples of the material being chlorinated. After suiiicient chlorine has been introduced, we blow the mixture with air or an inert gas, such as carbon dioxide, until the hydrogen chloride and free chlorine, ii. any, are substantially removed. While it is not essential, the chlorination mixture or the separated relatively pure halogenated hydrocarbons may be given a stabilizing treatment with dilute aqueous solutions of sodium sulfite, bisulflte, sulfurous acid, potassium permanganate, sodium hypochlorite, or the like. a

As an example of the manufacture ci a relatively pure chlorinated hydrocarbon, we describe here the manufacture of a relatively pure monochloro wax which contains approximately '26 carbon atoms per molecule. We started with 723A parts of a hydrocarbon wax having a melting point of 120 F. The wax was chlorinated until 72.5 parts by weight of chlorine had been The chlorinated wax was airblown to remove hydrochloric acid and uncombined resid ual chlorine, and then pressed at 85 F. The unchlorinated wax was reserved for further chlorination. The liquid portion was then dissolved in acetone, 350 parts of crude chloro wax being dissolved in 3,226 parts of acetone. The solution was chilled to minus 18 F. and 185 parts by weight of solid monochloro wax containing 10.3

normally liquid at room temperature.

Dichloro waxesand polychloro waxes prepared according to our method are suitable for use in any of the applications described in the prior art, where such dichloro waxes and polychloro waxes are required. Since they contain no unchlorinated wax or lower chlorinated waxes, they are particularly efficient in these applications and are a distinct improvement over the prior art wh ch used crude chlorination mixtures of approximately the proper chlorine content but which consisted of unchlorinated wax and more highly chlorinated wax.

While chlorine has been referred to above almost exclusively, it is to be understood that any of the halogens are suitable to make halogen derivatives of the paraffin hydrocarbons according to our method. Thus bromine, iodine, and fluorine may suitably be used to obtain the corresponding bromides, iodides and fluorides. For some purposes to which the halides are to be put, the bromine compounds are much to be desired over the chlorine compounds, since they are considerably more reactive. Where this is t the case, we halogenate with bromine, using a halogen carrier, such as halides of antimony, phosphorus, iron, various metals, and the like, and separate the brominated mixture into its components as described above in the case of the chlorine compounds. The iodine compounds of the pa'rafiin hydrocarbons may be prepared by direct lodination or by an indirect method. By the indirect method, the above described separation of mono-, di-, and polyhalogen derivatives may be employed in any step of the process. Thus we may separate a relatively pure monoor dichloro parafiin and convert it to the corresponding iodine compound, or we may convert I phenyl the crude halogenated mixture into a crude iodinated mixture and then separate into the I abilityoi chlorine above all the other-halogens.

'In preparing the lubricating oils of our invention, we use these relatively pure monochlor "waxes or dichlor waxes and treat them with metal derivatives of cyclic compounds of the -type"R'xH in which X is an atom ofan element selected from the right hand side of group VI of the periodic tables that is. oxygen, sulfur, selenium and tellurium, and R is an organic radical, containing at least .one cyclic nucleus. We prefer to use the cheap sodium derivatives I but other alkali, alkaline earth and heavy metal derivatives oi theR/XH compounds may be used. These cyclic compounds may be monocyclic, bicyclic or polycyclic, such as phenol, cresols,

'xylenols, phenylethyl alcohol, naphthols, hy-

droxydiphenyls, diand triphenyl carbinols, cyclohexanol, methyl cyclopentanol, thionaphthols, selenophenol and the like. Even heterocyclic phenols such as 8-hydroxy quinoline may be used. It appears to be particularly advantageous to have at least one alkvl group attached to the ring as in p-tert.-butylphenol, octadecylphenol, pentacosylphenol, amyl cyclohexanal, and the like. Other substituting groups may be present as in p-nitrophenol, p-hydroxybenzaldehyde, amyl salicylate, p-hydroxyacetophenone, o-hydroxybenzophenone, phenol sul- -fonic acid, its salts, esters and amides, vanillin, eugenol, thymol, mesitol, carvacrol, o-chloro-' phenol, tri-iodophenol, pentachlorophenol, nitrochlorophenols, o-methylaminophenol, picramic acid, m-hydroxyazobenzene, thiophenol, selenocresol, resorcinol, hydroquinone monomethyl ether o-chlorobenzyl alcohol, phenylethyl aloo hol, cinnamyl alcohol, and the like.

The reaction whereby our lubricating oils are produced proceeds at satisfactory rates at about 200 C. with most of the ring R'XH compounds and most of the halogenated aliphatics, but temperatures between 100 C. and 300 C. may be used, provided the reaction is not too slow or provided the product is not converted to dark colored products of relatively low viscosity index.

It will be obvious that our relatively pure wax and metal derivative must be substantially dry in order to carry out this reaction. We may use purchased dry metal phenolates or alcoholates or they may be prepared and treated with the halogen compound in the same reaction vessel. We mix the solid metal derivative with the halogen compound and keep the mixture agitated during the reaction. Usually the mixture is more difllcult to agitate at first than after the reaction has proceeded for a time.

We add water to the reaction mixture and -wash out metal halide and excess metal derivative from our synthetic oil. Usually the oil needs only to be dried and this may be accomplished in any suitable manner. For example, we may use a vacuum dehydrator.

The following examples are given as illustrations and not as limitations:

Example 1 A mixture of 94 parts of phenol and 44 parts I of sodium hydroxide in 300 parts of toluene was heated. The condensate was separated, discard- Example 2 A mixture of 108 parts of o-cresol and 44 parts .of sodium hydroxide were melted together and heated at 110-140" C. for two hours, poured out on a cold surface and pulverized. It was sub stantially water-free. To this solid was added 200 parts of our relatively pure monochlor wax and the mixture was heated at C. and then at l60-190 C. for one hour. Mixture was cooled, washed, steamed, and dried. It had a viscosity of 89.4 at 100 F. and 40.2 at 210 F.

The viscosity index was 160.4.

Example 3 As an intermediate, a tetrawaxylated phenol was prepared as follows: To a mixture of 94 parts of phenol and 1,550 parts of our relatively pure monoclor wax was added 50 parts of anhydrous aluminum chloride at about 65 C. The temperature was raised to 120 C. during 20 minutes and then to C. in 90 minutes. The mixture was cooled, decomposed by the addition of dilute hydrochloric acid, washed thoroughly with dilute acid, water, and dried.

A mixture of 900 parts of the tetrawaxylated phenol,- 34 parts of potassium hydroxide and 3,000 parts of toluene were heated as described in Example 1 until no more water was formed. Then 232 parts of our relatively pure monochlor wax was added and, after removing the toluene, the mixture was heated at -200 C. for two hours. The oil obtained from the mixture as described in Example 1 was chlorinefree and had a viscosity of 233.1 at 100 F. and 56.3 at 210 F. The viscosity index was therefore 148.1.

Example 4 A blend of 40 per cent by volume of the product of Example 2 with 59 per cent of a Mid- Continent neutral oil (viscosity 225 at 100 F.) and 1 per cent of a mixture of 75 per cent bright stock and 25 per cent of a naphthalene-chlorwax condensation product had a viscosity of 141.3 seconds at 100 F. and 43.1 seconds at 210 F. The viscosity index of the pale oil was 85 while that of the blend described-was 110.7.

Example 6 We may condense 130 parts of the anhydrous assess? sodium derivative of benzyl alcohol with 200 parts of a relatively pure monochlor wax and follow the procedure of the preceding examples to obtain another product of our invention.

Example 7 The mixture of 1,845 parts of the anhydrous calcium derivative of o-chlorobenzyl alcohol with 2,000 parts of our relatively pure monochlor wax when treated by the procedure of the preceding examples gives another product of our invention.

Example 8 The condensation product of 1,300 parts of sodium cresolate with 1,260 parts of our relatively pure dichlorowax gives another product of our invention.

Example 9 The condensation product oi the sodium derivative of cyclohexanol with our relatively pure monochlor wax gives another product of our invention.

It is to be understood that any or all of these reactions may be carried out under atmospheric, subatmospheric, or superatmospheric pressure. Furthermore, various other factors and details may be changed within wide limits within the spirit of our invention. Our invention lies primarily in providing an application of a known chemical reaction using our relatively pure halogen compounds to manufacture lubricating oils having extremely high viscosity indices. While we do not wish to claim the old processes, we do wish to claim all novelty inherent in our processes as broadly as the state of the art permits.

If desired, our product may be prepared in such a manner as to leave some residual halogen. This halogen will remain in the aliphatic part of the ether molecule. For example, we may condense one molecular proportion of a relatively pure dichlorwax with 1 or 1.5 molecular proportions of a metal phenolate or alcoholate. Or we may cause the condensation to proceed so as to remove halogen completely from the aliphatic part of the ether but use a halogenbearing aromatic hydroxy compound such as p-chlorobenzyl alcohol, o-chlorphenol or the like. If desired, a halogen-free condensation product may be halogenated to obtain a halogen-bearing lubricating oil. Any of these halogen-bearing products have superior lubricating properties, particularly in film strength as compared to the halogen-free lubricating oil.

Other elements such as sulfur, nitrogen or phosphorus may be present in our lubricating oil molecule. For the former purpose we may use substituted reagents in the condensation such as p-nitrophenol, 2-chlor-3 amino-pentacosane, l-mercaptonaphthyl disulfide, hydroxyphenyl diphenyl phosphate, o-hydroxyphenyl diamylphosphine and the like. The finished lubricating product may be so made that it will contain from 0.2 to 20% by weight of one of the halogens, su.- fur, nitrogen, phosphorus or combinations of two or more of these- Generally quantities ranging from only 0.2 to 5.0% of these elements are contained in the lubricant. We may add from 0.5 to 20% of other oxygen hearing organic compounds, halogen-containing or halogen-free, such as diphenylene oxide, chlorodiphenylene oxide, chlorinated diphenyls, methyl dichlorostearate, benzyl sulfide, tricresyl phosphate, tri (2-ethylhexylphenyl) phosphite, ben-' zyl sulfone, sulfurized methyl linoleate, diamyl is Within the scope of our claims.

xanthate, lauryl thiocyanate and the like. Furlike. Examples of some of these blends are:

Example 10 Per cent Condensation product of Example 2 00.0 Sulfurized methyl iinoleate (10% S) 10.0

Example 11 Condensation product of Example 2 98.0 Triphenyl phosphite 1.0 Chlorodiphenylene oxide 1.0

Example 12 Condensation product of sodium thiocresolate and monochlor wax 99.0 Methyl dichlorostearate 1.0 Example 13 Condensation product of Example 2 97.8 Solution of 25 per cent naphthalene-chlorwax condensation product in per cent of bright stock 1.5 Sulfurized methyl esters of corn oil acids 0.5 Tin phenylstearate 0.2 Example 14 Cresoxy wax (condensation product of Example 2) 75.0 Condensation product of sodium thionaphtholate and monochlor wax 25.0

Example 15 Cresoxy wax l 18.0

Condensation product of sodium S-hydroxy- It will be seen that we have accomplished the purpose of our invention; namely, to utilize petroleum hydrocarbons of loweconomic value to produce high viscosity index lubricating oils of great economic value.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, we claim:

1. A lubricating oil having a viscosity index of over 90, comprising principally an ether of the type RXR' where R is a high molecular weight aliphatic radical having at least 13 carbon atoms, R is an organic radical containing at least one cyclic nucleus, and X is an atom of an element selected from the right-hand side of group VI of the periodic table.

2. A lubricating oil having a viscosity index of over 90, comprising principally an ether of the type RXR' where R is a high molecular Weight aliphatic radical having at least 13 carbon'atoms,

R is an organic radical containing at least one 3. A lubricating oil having a viscosity index of over 90, mprising principally a thioether or the type RS where R is a high molecular weight weight aliphatic radical having at least 13 carbon,

atoms and R is an organic radical containing at least one cyclic nucleus.

5. A lubricating oil having a viscosity index 01 over 90, comprising principally a telluro-ether of the type RTeR where R is a high molecular weight aliphatic radical having at least 13 carbon atoms and R is an organic radical containing at least one cyclic nucleus.

6. A lubricating oil having a viscosity index of over 90, comprising principally a mixed cyclicaliphatic thio-ether with at least 13 carbon atoms in the aliphatic radical.

7. A lubricating oil having a viscosity index of over 90, comprising principally an ether ofthe type RXR where R is a high molecular weight aliphatic radical having at least 13 carbon atoms and R' is the radical of a cyclic compound of the type R'XH in which X is an atom of an element selected from the right-hand side of group VI of the periodic table.

8. A process for the production of lubricating oils having viscosity indices of over 90, comprising the steps of halogenating paraflln hydrocarbons whose monochloro derivatives melt lower than the hydrocarbons themselves, separating the mono-, di-, and polyhalogenated hydrocarbons from each other and from unhalcgenated hydrocarbons .and separately replacing the halogen of each of the said relatively pure halogenated hydrocarbons by means of a metal derivative of a cyclic hydroxy compound of th type R'XH in which R is an organic radical containing at least one cyclic nucleus andX is an element selected from the right-hand side of group VI of the periodic table.

9. A process for the manufacture of lubricating oils having viscosity indices 01' over 90, comprising the steps of halogenating paraflin hydrocarbons whose monochloro derivatives mel-t lower than the hydrocarbons themselvea'separating the mono-, di-, and polyhalogenated hydrocarbons from each other and from unhalogenated hydrocarbons and separately replacing the halogen of each of the said relatively pure halogenated hydrocarbons by means of a metal thiophenolate.

10. A process for the production of lubricating oils having viscosity indices of over 90, comprising the steps of halogenating parafiin hydrocarbons whose monochloro derivatives melt lower than the hydrocarbons themselves, separating the mono-,' di-, and polyhalogenated hydrocarbons from each other and from unhalogenated hydrocarbons and separately replacing the halogen of each of'the said relatively pure halogenated hydrocarbons by means of a metal derivative of an aromatic thioalcohol.

11. A process for the production of lubricating oils having viscosity indices of over comprising the steps of halogenating paraffin hydrocarbons whose monochloro derivatives melt lower than the hydrocarbons themselves, separating the mono-, di-, and polyhalogenated hydrocarbons from each other and from unhalogenated hydrocarbons and separately replacing the halogen of each of the said relatively pure halogenated hydrocarbons by means of a cyclic thioalcohol.

12. A lubricating oil having a viscosity index of over 90, comprising principally an ether of the type RXR where R is a high molecular weight aliphatic radical having at least 13 carbon atoms and R is an organic radical containing at least one aromatic nucleus and X is an element selected from the right-hand side of group VI of the periodic table.

13. A lubricating oil having a viscosity index of over 90, comprising principally an ether of the type RXR where R is a high molecular weight aliphatic radical having at least 13 carbon atoms, R is an organic radical containing at least one aromatic nucleus, and X is an element selected from the group consisting of oxygen, sulfur, selenium, and tellurium. I

' LLOYD L. DAVIS.

BERT H. LINCOLN. GORDON D, BYRKIT.