US3766285A - Synthetic oils - Google Patents

Abstract

THE PRESENT INVENTION RELATES TO SYNTHETIC OILS WHICH ARE TERTIARY-ALKYLATED BENZENE AND -NAPHTHALENE, WHEREIN THE TERTIARY ALKYL SUBSTITUENTS CONTAIN FROM 7 TO 44, PREFERABLY AN AVERAGE OF FROM 14 TO 44 CARBON ATOMS. THE COMPOSITIONS HAVE UTILITY AS HYDRAULIC OILS, AS LUBRICANTS, AND IN THE FORMULATION OF GREASES. THE TERTIARY ALKYL-BENZENES AND -NAPHTHALENES HAVE HIGHER BOILING POINTS AND LOWER VISCOSITIES THAN THE NATURAL PETROLEUM OILS OF THE SAME AVERAGE NUMBER OF TOTAL CARBON ATOMS, THEREBY PROVIDING A SUPERIOR PRODUCT WHERE LOW VOLATILITY AND HIGH FLASH POINT AT A GIVEN VISCOSITY ARE REQUIRED. THE SUBSTANTIAL ABSENCE OF A HYDROGEN ATOM ON THE CARBON ALPHA TO THE BENZENE RING MAKES THE COMPOSITIONS OF THE PRESENT INVENTION MUCH SUPERIOR IN OXIDATION AND THERMAL STABILITY AS COMPARED TO THE PRIMARY AND SECONDARY ALKYL BENZENES AND NATURAL PETROLEUM OILS WHICH ARE AVAILABLE.

Description

United States Patent 3,766,285 SYNTHETIC OILS Jesse K. Boggs, Houston, Tex., and Arthur W. Langer, Jr., Watchung, NJ., assignors to Esso Research and Engineering Company No Drawing. Filed Dec. 28, 1970, Ser. No. 102,173 Int. Cl. C07c /04 U.S. Cl. 260-668 R 6 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to synthetic oils which are tertiary-alkylated benzene and -naphthalene, wherein the tertiary alkyl substituents contain from 7 to 44, preferably an average of from 14 to 44 carbon atoms. The compositions have utility as hydraulic oils, as lubricants, and in the formulation of greases.

The tertiary alkyl-benzenes and -naphthalenes have higher boiling points and lower viscosities than the natural petroleum oils of the same average number of total carbon atoms, thereby providing a superior product where low volatility and high flash point at a given viscosity are required. The substantial absence of a hydrogen atom on the carbon alpha to the benzene ring makes the compositions of the present invention much superior in oxidation and thermal stability as compared to the primary and secondary alkyl benzenes and natural petroleum oils which are available.

The present invention relates to synthetic oils for use in a number of services, such as hydraulic oils, lubricating oil base stocks, base stocks for grease formulation, etc. The compounds have a higher boiling range and higher flash point than oils of the same viscosity which are from conventional processing of petroleum. Further, the compounds of the present invention are much more resistive to oxidation and thermal degradation than primary and secondary-alkylated aromatics since they do not possess significant amounts of benzylic hydrogens (a hydrogen atom on the alpha carbon to the benzene ring). They are also superior to conventional petroleum oils with respect to these characteristics.

The compounds of the present invention are predominantly tertiary alkylated-benzene and -naphthalene. Benzene may be either mono or disubstituted, whereas naphthalene will be mono or higher substituted.

The composition of the present invention consists essentially of one or more compounds which correspond to the structural formula:

wherein R R and R are alkyl groups,

R, is hydrogen or a t-alkyl group,

A is benzene or naphthalene, and the total number of carbon atoms in all substituents attached to A is from 7 The composition contains less than about 40 weight percent, preferably less than about 15 weight percent, of compounds possessing benzylic hydrogen atoms. Where A is naphthalene, R is hydrogen, usually.

The compositions may, if desired, be hydrogenated to saturate the aromatic nucleus. In such case, A will be a naphthenic radical.

The total number of carbon atoms in alkyl substituents, whether in a singlesubstituent or in two substituents, will range from 7 to 44, preferably from 14 to 44. The dialkyl- 3 ,766,285 Patented Oct. 16, 1973 "ice benzenes, because of their higher viscosity, are particularly suitable for grease formulations, whereas the monoalkylbenzenes are particularly useful in lubricating oil and hydraulic oil service; however, t-alkyl benzenes may be used as grease base oils where the t-alkyl group contains enough carbon atoms (e.g., 27 carbon atoms). Exemplary corn pounds for various uses are C H t-alkyl benzene (hy draulic oil for low temperature service), C H t-alkyl benzene (lube oil), and C27H55 t-alkyl benzene (grease base oil). In each of the above examples, the carbon and hydrogen amounts refer only to the t-alkyl substituent and do not include those in the benzene nucleus. The numbers represent the average carbon and hydrogen content of the substituents.

The compounds of the present invention are prepard by the method disclosed and claimed in copending application Ser. No. 101,921, entitled Selective Tertiary Alkylation of Aromatic Hydrocarbons by Jesse K. Boggs, filed on an even date herewith, the disclosure of which is incorporated into this application by reference. In that copending application, it is disclosed that the tertiary alkylation of aromatic hydrocarbons, utilizing bulky tertiary alkyl substituents, can be accomplished with selectivity and high yield only if a tertiary alkyl halide is used as the al-kylating agent and only if the evolved hydrogen halide is rapidly removed from the reaction zone, e.g., by operating under substantially reduced pressure.

As will be hereinafter more fully spelled out, a large number of synthetic oils have been prepared by the process of the copending application. These compositions are superior in oxidation resistance and in the resistance to thermal degradation.

GENERAL The compositions of the present invention are useful as lubricants (oils and greases) and as hydraulic oils. The particular compound or mixture of compounds will be chosen to meet the needs of the specific use to which the product will be put. For lubrication service, the average number of carbon atoms in substituent groups will be from 14 to 44. When it is desired to obtain the lowest viscosity for a given boiling range, benzene will be the nucleus. Generally, the lower to middle range viscosity (i.e., from 2 to 6 cs. at 210 F.) alkyl benzenes will be used as a lube oil base stock, while high viscosity (e.g., greater than 6 cs. at 210 F.) will be used as grease bases. The viscosity index (VI) improves as one R group of the t-alkyl substituent becomes longer, but the pour point also increases. For some uses (e.g., as a textile lubricant) the VI and pour point are not critical-the low volatility for a given viscosity exhibited by these compounds is the desideratum. For other uses, such as automotive engine lubricants, the VI and pour point are important and are balanced off by selecting a proper tertiary-alkylated compound (or, usually, mixture of compounds) prepared in accordance with the present invention. The pour point is reduced by using a mixture of compounds rather than a single, pure compound.

The compounds of the present invention exhibit a lower volatility for a given viscosity and a better balance of viscosity and boiling point for a given number of carbon atoms as compared to prior art lubricant compositions.

OLEFINS SUITABLE AS HALIDE SOURCES The t-alkyl benzenes and naphthalenes of the present invention are obtained by alkylating the aromatic nucleus with a suitable t-alkyl halide. A preferred source of t-alkyl halides is the product obtained by hydrohalogenation of the mixed 2-alkyl-1-alkenes produced by dimerization of a-olefins of differing carbon numbers. The resulting mixture of t-alkyl halides provides alkylated aromatic hydrocarbon mixtures of, superior viscosity, viscosity index and pour point characteristics. Where a single wolefin is used as a dimerization feedstock, the resultant olefin presence of a suitable catalyst, such as diisobutyl aluminum hydride [Al(isobuty1). I-I]. For example, from about 0.5 to 5.0 weight percent of diisobutyl aluminum hydride in the a-olefins forms the reaction mixture at elevated temperatures (e.g., 250 F. to 450 F.) and;

modest pressure (e.g., 0 to 100 p.s.i.g.) for 1 to 30 hours. The reactionrproceeds as follows:

when heated during distillation and/or in an acidsystem (A1 0 or HCl), the olefin product isomerizes:

In either case, the product ,upon hydrochlorination would be the same, 7

the tertiary chloride alkylating agent.

For convenience in discussing the structures of the tertiary halides, the number of carbon atoms in the K group around the central carbon atom are referenced by the corresponding numerals as shown below: General Structure 7 Example 7 Ba CH3 lh--R; CtIIn-C-CrrHts R, R2, R3 structure 4-1-12 structure ably balancing theratio of low-boiling solvent to benzene,v

and the reaction temperature and pressure. A. Friedel- Crafts catalyst (preferably FeC1 is used to promote the alkylation reaction. The HCl which is evolved is. rapidly held within the desired range and the reaction products withdrawn in the vapor phase to the controlled vacuum. line. The reaction products (mainly HCl) and volatilized liquid (aromatic hydrocarbon or cosolvent) were removed at a rate sufiicient to maintainthe hydrogen halideconcentration in the liquid phase at the indicated level. A stripping period at even further reduced pressure was usually employed at the end' of the vacuum runs. In some runs, where atmospheric pressure was employed, the vacuum was not drawn and the reflux condenser was allowed to reach equilibrium with the. outside air.

Example 1 Alkylation of benzene with 3-chloro 3 ethylpentane (22-2) using conventional alkylating conditions. This example shows that the use of atmospheric pressure is unsuitable with A1Cl leading to the formation. of nontertiary alkyl product, even when using a C t-alkyl chloride.

A S-Iiter'flask in a water'bath was used for this example, and it was equipped with five outlets for a. calibrated. dropping funnel, a thermometer, an inlet for liquid butane,

' a vent tube, and a magnetic stirrer.

The pot was charged with 585 g. of prechilled dry benzene, 13 g. of anhydrous AlCl and 598 g. of butane. The dropping funnel was charged with 135 g. of 3-c-hloro-3- ethylpentane and 585 g. of dry benzene. The contents, of thedropping funnel were added over a period of 1.6 hours and the temperature in the flask allowed. to rise from an initial 7 C. to about 28.5 C. The pressure was 760 mm. Hg. After completion of the reaction, the product was water washed and the butane and benzene stripped. from the reaction product. Gas chromatographic and NMR analyses were then carried out to determine that the yield was 83% of alkylate but that over 99% of the product was nontertiaryin structure. 7

Example 2 Alkylation of benzene with 2-chloro-2-methylhexadecane l-1-14) chloride using ferric chloride as a catalyst. The flask was charged with 1.6 g. of ferric chloride (anhydrous) and 24 g. of dry benzene. The dropping tunnel was charged with *24 g. of dry benzene and 28 g. of the (l114) chloride. The flask contentswerechilled to about 5 C., pressure adjusted at 60-75 mm. Hg and the. contents of the dropping funnel added over a period of 20 minutes. The temperature was held at 3-'-7 C; and the reaction proceeded very rapidly ,assho'wn by vigorous boiling and the evolution of HCl gas through the bub- V bler. After the chloride was added, 5 g. of additional ben zene' were added and conditions maintained for a further 7 40minutes. After this time, the pressure was reduced to removed from the reaction zone to minimize the formai tion of undesirable secondary alkyl isomers.

EXAMPLES In order to illustrate the production of thhe compositions of the present invention, the following examples are given. In most of these examples,.the reaction was carried out in a three-neck, 250 m1. flask, connected to a reflux about 20-30 mm. Hg' and held for 15 minutes. to strip.

the reaction liquid phase of remaining volatile components. The contents then were poured over an ice-salt mixtureto terminate the reaction. After working up the product by three (aqueous) saturated NaCl washes (100 ml. each) and filtering, the benzene was removed on arotating evaporator. The yield of stripped product was 29.4

condenser and bubbler and, also to a source of controlled vacuum, with a dropping funnel being provided for the introduction of a liquid feed. The reaction flask was provided with .a thermometer, a magnetic stirrer and a cooling bath. In the examples, the Friedel-Crafts catalyst in the aromatichydrocarbon was charged to the flask, while 7 for the solubil ty of HCl in benzene. At atmospheric pres sure and the same temperature, the calculated HCl concentration would have been 0.0529 mol fraction. 7

Example 3 Alkylation of benzene with 2-chloro-2i-methylhexadecane 1-1-14) using AlCl as a catalyst. The flask was charged with 24 g.'of dry benzene and 1.3 g. of anhydrous aluminum chloride. The dropping funnel was charged 7' with 24 g. of dry benzene and 28 g. of (1-1-14) chloride. The flask contents were chilled to 6-10 C., the pressure adjusted to 50-60 mm. Hg absolute, and the contents of the dropping funnel added over a period of 21 minutes. The reaction was held an additional 55 minutes at a pressure of 50-60 mm. Then full house vacuum (20-30 mm.) was applied and held for an additional 15 minutes. The product was worked up as in Example 1 and 26.1 g. of yield were obtained. The maximum HCl concentration during the reaction was calculated at 0.00450 mol fraction. Under the same conditions at 760 mm., the concentration would have been 0.0488 mol fraction.

The product was examined by NMR and found to contain only 16% nontertiary alkylbenzenes and 84% desired tertiary alkylbenzene.

Example 3 illustrates that aluminum chloride can be used as a catalyst under our preferred conditions, with only .a .small amount of undesiable isomerization occuri Example 4 This example shows that with FeCl benzene cannot be successfully alkylated with the C (1-1-14) olefin rather than the (1-1-14) chloride. The flask was charged with 24 g. of dry benzene and 1.6 g. of FeCl (anhydrous). The dropping funnel was charged with 24 g. of benzene and 24 g. of the (l-1-14) branched olefin. The flask and its contents were held with stirring at atmospheric pressure and C.'while the benzene/olefin mixture in the dropping funnel was added over a period of 20 minutes. The ice bath was removed and the flask warmed to room temperature (25 C.) for an additional hour. One milliliter samples were taken at 15, 30 and 45 minute intervals after the start and at the end of the reaction. After 1 hour and 20 minutes, the reaction mixture was poured over an ice-salt mixture, separated and washed three times with 100 ml. of a saturated NaCl aqueous solution. It was paper filtered and benzene removed on the rotating evaporator. A yield of 21.6 g. was obtained, but gas chromatograph data showed no alkylation product in any of the samples.

Example 4 illustrates that with FeCl tertiary alkylation with the olefin cannot be c-arried out directly, but that the use of the alkyl halide is necessary.

Example 5 (dialkylation) This example shows the alkylation of benzene with two tertiary alkyl groups. The procedure of Example 5 was similar to that of Example 1, but was carried out in two steps and in equipment which was larger than that used in Example 1. In step 1, 1560 g. of dry benzene and 24.3

previously described. The product was distilled to recover the tertiary amylbenzene overhead (yield 387 g.) and this was used as the charge for the second step. Under the conditions employed, the maximum HCl concentration was about 0.0277 mol fraction as compared to 0.0515 mol fraction which would have been present at 760 mm. About 90% of the feed chloride was converted to give a mixture of about 2.6 mols of crude monotertiary amylbenzene and 0.14 mol of crude ditertiary amylbenzene.

119 g. of the tertiary amylbenzene from step 1 and 5.7 g. of FeCl (anhydrous) were charged to the flask. The dropping funnel was charged with 176 g. of 2-chloro-2- methyltetradecane (1-1-12). The alkyl chloride was added over a period of 1 hour to the flask which was maintained under a temperature of 0 to 5 C. and a pressure of 40 mm. Hg absolute. It was held for an additional hour underthose conditions and the temperature then raised to 20 C. for 15 minutes and the pressure thereafter reduced to 15 mm. Hg for an additional 20 minutes. The product was worked up and examined to determine the nature of the product. Only about 15% of the product contained a hydrogen atom alpha to the ring.

Although some isomerization did take place with the heavier fractions, the alkyl attachments remained predominantly tertiary. This is true even in the bottoms fraction recovered from step 1 where the maximum nontertiary attachment was seen to be 15 by NMR examination. The calculated maximum HCl concentration in the second step was 0.00349 mol fraction as compared to 0.0585 for the same alkylation if conducted at 760 mm. Hg pressure.

The di-t-alkyl product was of the formula:

This example shows the production of a dialkyl benzene having no hydrogen atoms alpha to the ring.

Examples 6 through 14 Following the same general procedure as above described, a number of other runs were made with different alkylating agents and with different Friedel-Crafts catalysts. The results of these runs are tabulated below in Table I, wherein the alkylating agent is identified by the number of carbon atoms in R R and R Table I illustrates that tertiary alkylation of benzene has been accomplished in good selectivity so that the product is the improved synthetic oil of the present ing. of FeCl (anhydrous) were charged to the flask while vention.

- TABLE I.ALKYLATION 0 BENZENE WITH TERTIARY AKLYL CHLORIDES Conver- Press., sion Selec- Example Alkyl mm. Max. H01 Reaction Temp., mo tivity, number agent Catalyst Hg mol tract. time, hrs. 0 percent percent FeCla 28 0.00142 1. 7 0 84. 8 95 FeCls 300 0. 01622 3. 0 12-22 92. 8 86-96 FeCh 300 0. 01820 4. 0 6-15 95. 8 91 FeOla 40 0.00300 2. 3 6 87 95 eGh -75 0. 00287 1. 9 6-20 90 FeCls 300 0. 01625 4. 0 12 95 80-96 (AlClQ-(FeCla); 39 0. 00221 0.5 14-18 3 96 95 (A1Cla)- (FeCla)a 62-95 0. 00455 0. 8 10-25 97 66. 4

1 Usually finished at lower pressures.

5 In stages (a) time of addition (0.5 to 1 hr.), (b) holding (1 hr.), (0) finishing (0.5 hr.). Times given in parentheses are those usually employed 3 In the actual run, some olefin was present; this conversion is calculated on the basis of tertiary alkyl chloride concentration.

butane :(1-1-2) were charged to the dropping funnel. The contents of the funnel were added over a 2 hour period, while the flask was maintained at 7-8 C. and 400 mm. pressure. Thereafter, the contents were held at 1.5 hours at -the same temperature and pressure. After 3.5 hours, the pressure was reduced to 100 mm. Hg and held for 15 minutes. The reaction was terminated by pouring Referring particularly to Table I, it should be noted that the selectivity of the alkylation reaction has been the mixture over an-ice-salt mixture and worked up as 75 a considerably lowerselectivity was encountered, it is to obtained by a suitable selection of reaction conditions.

be noted that'a higher 'purity'product could hav'e'bee'n catalyst was employed; the

For example, Example 7 showed a'selectivity in some boiling ranges as low as 86%. These compounds c an be separated by dist'illationfor the recovery or thefhigh purity product or conditions similar to those shown in Example 12 could be employed for highselectivity-(Le,

the pressure could be reduced to 40 mm.). Similarly in Example 11," the pressure/could be reduced for mi km shown below by structural formula, together with the vis- V J V use of the catalyst and proeedure of Example 13 raises the selectivity to 95%.

Thus it is seen that the present invention relatesto monoand di-t-alkylbenzeneshaying widely vary-ing carbon numbers in'theialkylgroup;"r I

The compounds produced by alkylation of benzene are cosity thereof where such measurement is available. The

viscosity in those instances is comparedf to'theviscosity of a. normal alkyl benzene;

:irxsm'ipsmummu FoRMULAs 7 I Monoalkyl benzenes, I

V, V So a; V 7 i vii. (is. at'100 F.-

I V p J Alkyl T T0 1 Example Number 1 R -Rr-Rycarbons eerbone t-Alkyl n-Alky ...-.;;-......-V......,V;M I. 02H; 7 M 2 2-2 V13'.-------.... .-l-:

H zHl Q V V 63H; '7 I 1-1-1 1o I -16 3.73 r

14-9 r 12 18' 1.9' L2 1444* 17' r 11 8.4: M42 x 17 2a'.. 84 24-8 12 '1s- 5.3

9 1 10] 7 2&- 21 .--..V.1..,.,--.. ,V..7 I 54-10 17 ea V I Dlallryl benzenes. 7V V 7 an. 14 2 20 is g "22 1- 1-12 V '-C12Hzs V (22H, 1-1-4 ill. 1 17 7; 2-2-2, V c zfisj 9 Example 15 Alkylation of naphthalene with 3-chloro-3-ethylpentane (2-2-2) using cyclohexane solvent. The flask was charged with 100 g. of cyclohexane solvent, 25.6 mols of naphthalene, and 1.6 g. of FeCl;; (anhydrous). The dropping funnel was charged with 13.5 g. of the (2-2-2) chloride. The addition was carried out over a period of 0.3 hour, and to the flask which was maintained at 20 C. and 65 mm. Hg. The reaction was hold for an additional 3 hours under the same conditions, and then for a half-hour at 20-30 mm. Hg. The product was worked up and found to contain no measurable benzylic hydrogen (a hydrogen atom alpha to the aromatic ring). Thus, by reducing the pressure and using cyclohexane as a boiling liquid, selective alkylation was accomplished.

The product had the structural formula:

Example 16 Alkylation of alpha methyl naphthalene with 3-chloro- 3-ethylpentane (2-2-2) using cyclohexane solvent. A run similar to Example 15 was made using 40 g. of cyclohexane, 28.4 g. of alpha methyl naphthalene and 1.6 g. of FeCl (anhydrous) in the flask, with 13.5 g. of 3- chloro-3-ethylpentane (2-2-2) in the dropping funnel. The addition was carried out over 0.13 hour, the flask being maintained at 22 C. and 65 mm. Hg. The reaction was held under those conditions for an additional 3 hours and then for 0.5 hour at 20-30 mm. Hg. After a workup of the product, the NMR analysis showed 65.2% alkylation based on the tertiary chloride. Ninety percent of the product was 3-ethyl-3-naphthylpentane and nearly 3-methyl-3-naphthylpentane with possible traces of 2-methyl-2-naphthylpentane. It is to be noted that although the tertiary alkyl group isomen'zed, the product was still a tertiary alkyl. No measurable quantity of benzylic hydrogen was found in the alkylated product. The maximum HCl concentration during alkylation was calculated to be 0.00034 mol fraction.

The primary product has the structural formula:

gi t.

ent process.

Example 17 Alkylation of t-butylbenzene with 3-chloro-3-methylpentadecane (2-1-12) in the presence of triethylamine. Thefiask was charged with 114 g. of -tbutylbenzene, 24.3 g. of anhydrous iron chloride, and 8.6 g. of triethylamine. The dropping funnel was charged with 14 g. of t-butylbenzene and 221 g. of 3-chloro-3-methylpentadecane (2-1-12). The addition was carried out for a total of 1.5 hours, while the flask was maintained at a temperature of 12-36 C. and 40 mm. Hg. The reaction was held under those conditions for anadditional hour and then the pressure was reduced to about 15 mm. Hg and held for about 0.5 hour. The product was worked up and found to represent a 24% molar yield based on the tertiary chloride. Only traces of benzylic hydrogen were discovered by NMR analysis, indicating that tertiary alkylation without isomerization to nontertiary forms had been obtained. It was noted that considerable interchange of alkyl groups had taken place, the highest boiling fractions 10 containing large amounts of di(3-methylpentadecyl)benzene:

C Ha C Ha Cribs-( JC12HZ5 32 's h s Example 18 The following examples are directed to alkyl benzenes having one or two alkyl substituents. The alkyl substituents were obtained by dimerizing a-olefins and then reacting the dimerization product with HCl. The a-olefins employed were C -C (even-numbered), in admixture or alone.

The resultant t-alkyl chlorides were reacted with benzene, using FeCl as a catalyst and employing the techniques more particularly described in copending applica tion Ser. No. 102,921, Selective Tertiary Alkylation of Aromatic Hydrocarbons by I. K. Boggs and filed on an even date herewith. After completion of the alkylation reaction, the products were separated by distillation.

The following dimerization products were obtained from an admixture of C C C and C a-olefins:

From these olefins, the corresponding t-alkyl chlorides were obtained by hydrochlorination.

The admixture of alkyl chlorides was reacted with boiling benzene in the presence of FeCl catalyst and under a vacuum to obtain a mixed t-alkyl benzene product. During alkylation, some desirable rearrangement by methyl shift may occur; e.g., from the halide, the

t-alkyl aromatic structures may also be obtained as well as the expected t-alkylated aromatic. The product exhibited an alkyl-substituent carbon number distribution as follows:

Mol percent Nil QC 1.0 QC 15.1 QC 32.6 0C 32.3 QC 19.0

fifi The symbol 0 indicates benzene nucleus; hydrogen quantities are omitted.

ethylene type C isoolefins and the corresponding tertiary alkyl chlorides. The olefin mixturewas made up of 34 mol percent of 10-methyleic0sene-9, 51 mol percent of i i t the alkylating' mixture to 293g.v of benzene and g; of

7 aluminum'chloride over a period of 60' minutes while IO-methyleicosene-IO, and 15 mol percentof Z-nonyldodecene-l:

CH; CH3 cingon=ir-cmn=i overpower- 0in -methyleleosene-9 IO-methyleicosene-IO o ibf V C=CH1- mHn V 2-nonyldodecene-1 V The tertiary alkyl chloride is derivedtrom the mixture; of three olefins, and has the structure:

' on, 1 QoH1o- 1eHn V a V V I p 1'q-ehloro ',"1o-m' k I J M I .7 'Aneumixtureorizss gr'of theolefin niixturegand 258g. of the alkyl chloride'plus 293 g. of benzene was added to 293 g. of benzene and 5 g. of A101 over a period of 60 minutes while stirring the liquid reaction mass. The temperature varied from 5 C. to C. during the reaction period. A vacuum was maintained, the pressure during the reaction being about 60 mm. Hg absolute. After termination of the reaction the product was recovered and found to have the following analysis:

The productxwas compounded to produce an aviation hydraulic fluid having the characteristics shown in Table Viscosity, cs. at 100 F Viscosity i ndax 97 Pour point, F -60 Flash point, F 470 Oxidation/corrosion stability 0 Pass Thermal/corrosion stabi1ity.. Pass I Blended as follows: Synthetic oil, 98 wt. percent; Trierasyl phosphate, I V

1 wt. percent; Antioxidant (ethyl 702), '1 wt. percent.

b The finished blended oil may also contain VI improver and pour depressants as desired.

a As determined by MILH27601A.

Example 20 Benzene was alkylated with amixture of internal C isoolefins and the corresponding tertiary alkyl chloride- The olefin mixture was made up of 32 volume percent of ylhexadecene-G: on,

i-6-methylhexadecene-5 and 68 volume percent of 6-meth- The tertiary alkyl chloride isderived from/both of theabove-mentioned olefins and has the structure:

An admixture of 139 g. of the olefin mixture, 274' g. of the alkyl chloride," and 293 g. of benzene was added as stirring the liquid reaction mass. The temperature varied 1 from 5 C. to 15 C;. during the reaction period; A vacuutn was maintained; the pressure during the reaction be-' ingabout 60 mm. Hg. absolute. After termination ofrthe reaction, the product was recovered and found to have t the following analysis; 7 a

The product was compounded to produce an aviation hydraulic fluid having the characteristicsshown inTable. IY

below;

I TABLE rvrnmrronnYnnnurzro rnurn b Sinners in f V 7 CH3 CH3 s ur-I J CniHn c a m -rCli CmH'zr,

(Example 20) (Examplem) Viscosity, 0S. at F 13.04 18. 99 Viscosity index. 37 97 Pour point, F- 55 60 Flash'pointfi F 420 470 Oxidation/corrosi stability Pass Pass Thermal/corrosion stability Pass Pass I Blended as follows: Synthetic oil, 98 wt. percentrTricresylphosphate, 1 wt. percent; Antioxidant (Ethyl 702), 1 wt. percent;

b The finished blended oil may also contain VI improver and pour depressants as desired.

As determined by MIL-H-27601A.

We claim: 7

1. A: composition useful as a lubricant and consisting essentially of an admixture of monosubstituted tertiary alkylbenzenes in the approximate proportions;

Mol percent C H t-alkyl benzene 1.0 C13H37 benzene C H t-alkyl benzene 32:6 7 C H t-alkyl benzene 32.3 C H t-alkyl benzene u- 19.0

chlorinated internal olefin, under conditions includan eifective amount of a Friedel-Crafts catalyst, V

a temperature from -l0 C. to +30 0.,

a pressure from 20 to mm. Hg absolute,

and in the presence of an ebullient liquid, said conditions being correlated so as to remove HCl from the reaction zone at a rate sutficient to minimize the formation of undesirable secondary alkyl isomers.

3. A composition consisting essentially of one or more compounds having. the formula:

13 14 wherein: 3,115,530 12/1963 Cohen 260671 B A is benzene or naphthalene, 3,234,297 2/1966 Cohen 260671 B R, is hydrogen or a tertiary alkyl group, 3,238,249 3/ 1966 Mirviss et al. 260-671 B R is methyl, 3,403,195 9/1968 Patton et a1 260-671 P R is a C or a C alkyl group, and 5 OTHER REFERENCES R is a C to C alkyl group.

4. A composition according to claim 3 wherein R is C alkyl and R is C alkyl.

5. A composition according to claim 3 wherein R is C8 alkyl and R2 is Cm 1 1 10 Pines et aL: JACS, vol. 71, November 1949, pp.

6. A composition according to claim 3 wherein R is C9 alkyl and R2 is C9 alkyL Pines et al.: JACS, vol. 75, February 1953, pp. 937-9.

References Cited Eglofi: Physical Constants of Hydrocarbons, vol. 3, 1946, pp. 144, 145, 152-5, 159, 165, 169-172, 174, 176, 177

CURTIS R. DAVIS,- Primary Examiner UNITED STATES PATENTS 15 CL 3,115,465 12/1963 Orloff et a1. 252 49.9 3,357,920 12/1967 Nacson 252-499 252 260 668 671 671 671 P 2,796,429 6/1957 Kreps et a1 260-671 B