US2500161A - Conversion of 1-olefins in the presence of lead tetraacetate - Google Patents

Description

Patented Mal-.14, rose OFFICE I CONVERSION OF 1-0LEF1NS IN THE PRES- ENCE F LEAD TE'IBAACETATE Francis M. Seger, Pltman, and Alexander N.

Bachanen, Woodbury, N. 1., assignorl to Socony-Vacnnm Oil Company, Incorporated, a corporation of New York No Drawing. Application am: 14, ms,

v Serial m. 44,40

9 Claims. (o1. zoo-683.15)

This invention has to do with hydrocarbon conversion and with synthetic lubricants or viscous oils prepared by such a conversion. More specifically. the invention is concerned with a new process for converting certain mono-oleilnic hydrocarbons to lubricants of outstanding quality.

It has now been discovered that normal alpha mono-olefins having from about 6 to about 12 carbon atoms per molecule are converted to synthetic lubricants when in contact with lead tetraacetate at elevated temperatures. The synthetic lubricants so formed are characterized by high viscosity indices, low pour points and high stability. These characteristics are such as to make these lubricants suitable for use alone or blended with other lubricants.

As indicated above, the mono-olefins of this invention are normal or straight chain alpha monoolefins and contain from about 6 to about 12 carbon atoms. Such mono-olefins are normally liquid at temperatures of the order of 20-25 C. Illustrative of such mono-olefins are the following: hexene-l, octene-l, decene-l, dodecene-l, and the like. Of such olefins, decene-l is preferred in view of the particularly outstanding characteristics of the lubricants formed therefrom. It will be clear from the foregoing examples that an alpha olefin may also be referred to as a l-olefin.

Not only may the foregoing mono-oleflns be used individually, but they may also be used in admixture with each other. In addition, olefin mixtures containing a substantial proportion of such mono-olefins may be used. 'Preferred of such mixtures are those'containing a major proportion of a normal l-olefln or of normal l-olefins.

Representative of such mixtures are those obtained by the cracking of paraflin waxes and other paraflin products, and those obtained from the Fischer-Tropsch and related processes. These hydrocarbon mixtures may contain, in addition to the normal l-olefin' or normal l-olefins, such materials as: other oleflns, parailins, naphthenes and aromatics.

Lead tetra-acetate used herein to convert the foregoing normal i-olefins to synthetic lubricants is well known, as are. methods by which it may be prepared. One typical method of preparation, forexample, involves reaction of lead dioxide (PbOz) and acetic anhydride. As contemplated herein, lead tetra-acetate may be formed in situ, as from lead dioxide and acetic anhydride. 7

Conversion or the foregoing normal l-olefins in the presence of lead tetra-acetate is eflected at elevated temperatures between about 400 F. and

F. The pressure to be employed depends upon the temperature used, and ordinarily a pressure suflicient to maintain the olefin in substantially the liquid phase is adequate. With temperatures within the 500-700" F. range, pressures of the order of 300-600 pounds per square inch are generally developed in the reaction vessel used. Reaction times will vary depending upon the particular olefin involved, quantity of olefin, temperature and, to a certain extent, pressure. In general, the higher the temperature employed, the shorter the reaction time required, the criterion used being the time required at a given reaction temperature to eflect substantial conversion of the normal l-olefin to a viscous oil. Generally, reaction times within the range of 1 to 10 hours are satisfactory.

With regard to proportions of olefin and lead tetra-acetate, satisfactory results may be obtained with as little as one mol of lead tetraacetate to fifty mols of a given normal l-olefin.

In such cases, however, much of the olefin is usually recovered unreacted. Large proportions of lead tetra-acetate, however, result in waste of this relatively expensive material without realizing corresponding enhancement of the. desired product. Excellent results are realized with from about 0.02 mol to about 0.4 mol of lead tetraacetate per mol of normal 1--olefin.

The process .contemplated herein is rather sim-' ply accomplished by mixing the normal l-olefin. and lead tetra-acetate in a shaker bomb type of reactor, replacing the air therein by an inert atmosphere of nitrogen or the like, and applying the desired temperature and pressure for a suflicient length of time to complete the conversion. It will be apparent to those skilled in the art that the process may be carried out in a batch procedure such as indicated, or may be carried out in a continuous or semi-continuous operation of the type ,widely used in the petroleum industry.

The following detailed examples are provided for the purpose of illustrating the process of this invention. It is to be understood, howeventhat the invention is not to be' considered as limited to I the specific normal l-olefin shown, or the conditions or operation set forth therein.

Example I A typical conversion was accomplished as follows: A. shaker bomb was charged with 280 grams (2.0 mols) of decene-l and 44 grams (0.1 mol) of lead tetraacetate. The air therein was replaced with nitrogen and the bomb heated toapproxi- 3 mately 500 F. (260 C.) for five hours. A pressure of 650 pounds per square inch developed in the bomb during the run.

The liquid contents of the bomb were filtered free of the relatively large amount of lead salt which was found to be present. A small amount of unreacted decene-l was distilled out at atmospheric pressure. A vacuum distillate cut was collected up to approximately 200 C. at 2 millimeters pressure. The residual oil weighed 60 grams and had the following characteristics:

Viscosity at 100 F., centistokes 44.22 Viscosity at 210 F. centistokes 7.40 Viscosity at 100 F., Saybolt, secs. 204.8 Viscosity at 210 F., Saybolt, secs 50.37 Viscosity index 132.6 Specific gravity 0.8423 Gravity, A. P. I 36.5 Neutralization number (N. N.) 0.5 Saponification number 4.5

Example II Decene-l was in contact with lead peroxide or dioxide (PbOa) and acetic anhydride, which most probably formed lead tetra-acetate in situ. The quantities used were: 280 grams (2.0 mols) of decene-l; 24 grams (0.1 mol) of PhD: and 41 grams (0.4 mol) of acetic anhydride.

The conversion and recovery procedures were effected in the manner described in Example I, with the temperature, pressure and time, respectively: 610 F. (321 0.), 1100 pounds per square inch, and 11 hours. The residual oil, 89 grams, thus obtained had the following characteristics:

Viscosity at 210 F., Saybolt, secs 47.27 Viscosity index 136.1

Specific gravity 0.8348 Neutralization number (N .N.) 0.3 Bromine number 12.6 Refractive index 1.4654

Pour point 30 It will be apparent that the present invention provides an efilcient and commercially feasible process for eflecting the conversion of normal l-olefins, of the character described above. This process is oi. value in the manufacture of synthetic lubricating oils, as well as in the manufacture of organic products (as the intermediate oils of Examples I and II) important as intermediates in organic synthesis.

From the characteristics of the products produced in the illustrative examples above, it will be apparent that the products are highly useful in reducing friction when placed between relatively moving parts, either alone or when blended with other lubricating oils. The synthetic oils impart desirable viscosity index (V. I.) and pour point characteristics to the oils in combination therewith, for, as indicated above, they have advantageous viscosity index and pour point properties. In short, the synthetic oils find utility in upgrading" other lubricants. Typical oils with which the synthetic oils may be blended are mineral oils such as are normally used in internal combustion and turbine engines. When so blended, the synthetic oils may comprise the major proportion of the final blended oil, or may even comprise a minor proportion thereof.

One or more of the individual properties of the synthetic lubricants of this invention may be further improved by incorporating therewith a small, but effective amount, of an addition agent such as a detergent, an extreme pressure agent, a foam suppressor, a viscosity index (V. I.) improver. etc. Typical detergents which may be so used are metal salts of alkyl-substituted aromatic sulfonic or carboxylic acids, as illustrated by diwax benzene barium sulfonate and barium phenate-barium carboxylate of a wax-substituted phenol carboxylic acid. Extreme pressure agents are well known; illustrating such materials are numerous chlorine and/or sulfur containing compositions, one such material being a chlornaptha xanthate. Silicones, such as dimethyl silicone, may be used to illustrate foam suppressing compositions. Viscosity index improving agents which may be used are typified by polypropylenes, polyisobutylenes, polyacrylate esters and the like.

contemplated also as within the scope of this invention, is a method of lubricating relatively moving surfaces by maintaining therebetween a film consisting of any of the aforesaid synthetic lubricants and blends thereof.

It is to be understood that the foregoing description and representative examples are nonlimiting and serve to illustrate the invention, which is to be broadly construed in the light of the language of the appended claims.

We claim:

1. The process for converting a normal, alpha mono-olefin having from six to about twelve carbon atoms per molecule, to a viscous oil characterized by high viscosity index and low pour point, which comprises: heating said olefin with lead tetra-acetate at a temperature between about 400 F. and about 700 F. for a period of time from about ten hours to about one hour, respectively, and under a pressure sufiicient to maintain the olefin in substantially the liquid phase.

2. The process for converting a normal, alpha mono-olefin having from six to about twelve carbon atoms per molecule, to a viscous oil characterized by high viscosity index and low pour point, which comprises: heating said olefin with from about 0.02 mol to about 0.4 mol of lead tetraacetate, per mol of said olefin, at a temperature between about 400 F. and about 700 F. for a period of time from about ten hours to about one hour, respectively, and under a pressure sufficient to maintain the olefin in substantially the liquid phase.

3. The process for converting n-decene-l to a viscous oil characterized by high viscosity index and low pour point, which comprises: heating n-decene-l with from about 0.02 mol to about 0.4 mol of lead tetra-acetate, per mol of n-decene-l, at a temperature between about 400 F. and about 700 F. for a period of time'from about ten hours to about one hour, respectively, and under a pressure sufiicient to maintain the olefin in substantially the liquid phase.

4. The process for converting n-decene-l to a viscous oil characterized by high viscosity index and low pour point, which comprises: heating one molar proportion of n-decene-l with about 0.05 molar proportion of lead tetra-acetate, at a temperature of about 500 F. for about five hours and under a pressure of about 650 pounds per square inch.

5. The process for converting n-decene-l to a viscous oil characterized by high viscosity index and low pour point, which comprises: heating one molar proportion of n-decene-l with about 0.05 molar proportion of PhD: and with about 0.2 molar proportion of acetic anhydride, at a temperature of about 600 F. for about eleven hours and under a pressure of about 1100 pounds per square inch.

ll 6. A viscous oil characterized by high viscosity index and low pour point. and obtained by: heating a normal, alpha mono-olefin having from six to about twelve carbon atoms per molecule with lead tetra-acetate at a temperature between about 400 F. and about 700 F. for a period of time from about ten hours to about one hour, respectively, and under a pressure sufiicient to maintain the olefin in substantially the liquid phase.

7. A viscous oil characterized by high viscosity index and low pour point, and obtained by: heating a normal, alpha mono-olefin having from six to about twelve carbon atoms per molecule with from about 0.02 mol to about 0.4 mol of lead tetra-acetate, per mol of said olefin, at a temperature between about 400 F. and about 700 F. for a period of time from about ten hours to about one hour, respectively, and under a pressure sufficient to maintain the olefin in substantially the liquid phase.

8. A viscous oil characterized by high viscosity index and low pour point, and obtained by: heating one molar proportion of n-decene-l with about 0.05 molar proportion of PhD: and with about 0.2 molar proportion of acetic anhydride, at a temperature of about 600 F. for about eleven liours and under a pressure of about 100 pounds per square inch.

FRANCIS M. SEGER. ALEXANDER N. SACHANEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,091,398 Sullivan et al. Aug. 31, 1937 2,117,022 Cramer May 10, 1938 2,262,804 Jean Nov. 18, -1941 FOREIGN PATENTS Number Country Date 366,112 Great Britain Jan. 25, 1932 OTHER REFERENCES Hutchinson et al.: Jour. Chem. Soc. (London), vol. 69 (1896), pages 212-221.

Claims (1)

1. THE PROCESS FOR CONVERTING A NORMAL, ALPHA MONO-OLEFIN HAVING FROM SIX TO ABOUT TWELVE CARBON ATOMS PER MOLECULE, TO A VISCOUS OIL CHARACTERIZED BY HIGH VISCOSITY INDEX AND LOW POUR POINT, WHICH COMPRISES: HEATING SAID OLEFIN WITH LEAD TETRA-ACETATE AT A TEMPERATURE BETWEEN ABOUT 400*F. AND ABOUT 700*F. FOR A PERIOD OF TIME FROM ABOUT TEN HOURS TO ABOUT ONE HOUR, RESPECTIVELY, AND UNDER A PRESSURE SUFFICIENT TO MAINTAIN THE OLEFIN IN SUBSTANTIALLY THE LIQUID PHASE.