US2500672A - Synthetic lubricants - Google Patents

Description

Patented Mar. 14, 1950 SYNTHETIC LUBRICANTS William E. Garwood, Haddonfield, John W. Brooks, Wenonah, and Alexander N. Sachanen, Woodbury, N. J assignors to- Socony-Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application June 8, 1949, Serial No. 97,921

This invention has to do with the condensation 01 normal, alpha mono-olefins, conjugated olefinic compounds and mercaptans or thiols.

A s is well known to those familiar with the art, oleiins have previously been polymerized; so also have vinyl aromatic hydrocarbons. Olefins and vinyl aromatic hydrocarbons have also been reacted together. copolymerization isgenerally incomplete. For example, when decene-l and styrene are copolymerized at 600 R. an oil containing a polystyrene cloud at room temperature (20-25 C.) is formed. The oil thus obtained possesses approximately the same oxidation stability as uninhibited Pennsylvania SAE W mineral oils. Vinyl aromatic hydrocarbons, such as styrene, when reacted with mercaptans form products characterized by very low viscosity indices. In effect, then, when any two of the foregoing reactants-olefins, vinyl aromatic hydrocarbons, and mercaptans-are reacted together, the yield 19 Claims. (Cl. 252-482) In the latter instance, however,

of viscousoil is either insufiicien't or the viscous oil suffers from one or more shortcomings, such as cloud formation, relatively low oxidation stability or low viscosity index (V. 1.).

It has now been discovered thatcertain normal, alpha mono-olefins condense with conjugated olefinic hydrocarbons and thiols, under conditions hereinafter" defined, with the formation of highly desirable viscous oils. These oils have molecular weights less than about 1000, generallywithin the range of 400 to 600. The oils so formed are free from the shortcomings of olefin-vinyl aromatic hydrocarbon copolymers, as illustrated by the l-decene-sty'rene copolymer referred to above. Further, the viscous oils of this invention are unusually stable. Catalytic oxidation stability tests demonstrate them to be superior to condensation products of decene-l alone, to condensation products of decene-l and styrene, and to uninhibited Pennsylvania type mineral oils. The characteristics of the new oils are such as to make them outstanding synthetic lubricants, for use alone or blended with other lubricants.

Reactonts The mono-olefin reactants of this invention are normal or straight-chain alpha compounds, and contain from five to eighteen carbon atoms per molecule. liquid at temperatures oi! the order of 2025 C. Illustrative of such mono-oleflns are the followingz pentene-l, octene-l, decene-l, dodecene-l, octadecene-l and the like. Preferred of such ole fins, however, are those having from eight to twelve carbon atoms per molecule, with decene-l representing a particularly desirable olefin It will be clear from the foregoing examples that an alpha olefin may also be referred to as a l-oleiin.

Not only may the mono-olefins of the aforesaid character be used individually in this invention, 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 l-olefin or of l-olefins. Representative of such mixtures are those obtained by the cracking of paraflin waxes and other paraflin products; those obtained from the Fischer-Tropsch and related processes.

These hydrocarbon mixtures may contain, in addition to the l-olefin or l-olefins, such materials as: other olefins, paraffins, naphthenes and aromatics. I

Olefinic' compounds contemplated herein for condensation with normal, alpha mono-olefins and thiols are of conjugated character and include aliphatic compounds and alkenyl-substituted aromatic compounds. are characterized by the grouping I I I l and conjugated alkenyl-substituted aromatic compounds are characterized by wherein A is an aromatic nucleus, an unsaturated Such mono-olefins are normally Conjugated olefins group of which is in conjugated relationship with the alkenyl group.

The coniugated paramnic hydrocarbons and derivatives thereof are represented by: butadiene, isoprene (Z-methyl butadiene) cyclopentadiene,

methyl isoprene; halogen-substituted materials benzene is {a typical and preferred example.

Vinyl-diphenyl is another illustrative mononuclear compound. Representative ankenyl-- substituted poly-nuclear hydrocarbons are vinyl naphthalene, vinyl anthracene, etc. Derivatives j of such hydrocarbons are also contemplated herein and include halogen-substituted materials such as p-chlorostyrene, alkoxy-su'bstituted 1 materials such as p-methoxy styrene, and the like. i

As will be noted from the character of the fore- 1 going typical substituted, conjugated oleflnic hydrocarbons, substituent groups which maybe present are those which do not interfere with the condensation of the conjugated oleflnic compound with the aforesaid alpha mono-olefin and thiol. In other words, a substituent group which i may be present in the conjugated oleflnic hydrocarbon is one which is substantially inert or un- 1 reactive in the condensation. The substituent group, however, generally modifies the character of the oil product, yet in all cases, the products are characterized by unusual stability and are useful as lubricants. By way of illustration. when p-chloro-styrene is used, the synthetic lubricant formed possesses extreme pressure properties. Similarly, a fluoro-substituted styrene imparts additional stability to the synthetic lubricant product as well as extreme pressure properties.

It will be understood, of course, that mixtures .of the aforesaid conjugated oleflnic hydrocar- 1 bons, and their aforesaid derivatives, may be used in place of the individual reactant. Similarly, mixtures containing substantially, preferably major, proportions of one or more of said con- .Iugated oleflnic compounds may be used. An example of such a mixture is a crude styrene containing ethylbenzene.

Preferred of the alkenyl-substituted aromatic As indicated above, mercaptans or thiols are condensed herein with the aforesaid normal, al-

pha mono-oleilns and conjugated oleiinic compounds, and such compounds may be represented :by the general formula RSH, wherein R may be hydrogen; a hydrocarbon group such as alkyl,

alkaryl, aryl, or aralkyl; or a heterocyclic grou such as thienyl (for example) t-butyl thiophenol, t-butyl thionaphthol; aryl thiols-thiophenol, e-thionaphthol, p-thlonaphcompounds, in view of the outstanding character v of the products obtained therewith is styrene.

thol; aralbl thiols-bensyl thiol, phenyl 'ethyithiol; heterocyclic thiols-thiophenethiol, fur-anthiol. Thiophenethiol is described, together with methods for its preparation, in copending application Serial No. 721,454, filed January 10, 1947. Polythiols are also contemplated herein; however, such materials are generally used in smaller quantities than the monothiols.

Of the thiols represented by the general formula, those containing a hydrocarbon or heterocyclic group are preferred. Of the latter compounds, n-butyl mercaptan, thiophenol and thiophenethiol' are particularly preferred inasmuch as synthetic lubricants obtained therewith are of outstanding character.

Reaction conditions Condensation of the aforesaid reactants is affected at elevated temperatures. It appears that temperatures as low as 400 F. and as high as 900 1". can be used in some instances, however, temperatures of the order of about 500 F. to about 800 F. are most satisfactory. The preferred temperature range. as shown'hereinbelow, is from about 600 F. to about 750 F.

Condensation is generally complete in from one to twenty hours, preferably from three to ten hours, with the higher reaction temperatures being used for the shorter reaction periods and with the lower reaction temperatures being used for the longer reaction periods. a

Pressures ranging from atmospheric to 4000 lbs. per square inch may be used. In general, it is desirable to use suflicient pressure to maintain the reactants in liquid state.

Proportion of reactants can be varied considerably to form products suitable for different uses. With one molar proportion of normal, alpha mono-oleilns as the basis, from about 0.01- to about one molar proportion of coniugated oleflnic compound, such as a vinyl aromatic compound, and from about 0.001 to about one molar proportion of thiol, provide satisfactory products. Preferred proportions for forming outstanding synthetic lubricants, however, are from about 0.05 to about 0.5 molar proportion of conjugated oleflnic compound and from about 0.01 to about 0.5 molar proportion of thiol, with one molar proportion of normal, alpha mono-olefin. By proper proportioning of reactants, synthetic lubricants may be obtained, or blending stocks for use with mineraloils to improve the latter in regard to oxidation stability, viscosity index, and/or pour point properties, may be obtained. Condensation products which are useful as lubricating oil additives or adjuvants in concentrations as low as two per cent in mineral oil to eflectively stabilize the latter against oxidation, are formed when a relatively large amount of thiol and conjugated oleilnic compounds are used. Products of the latter type however, are characterized by low viscosity indices. As demonstrated hereinbelow in the illustrative examples, optimum conditions for forming the synthetic lubricants may be used, and the resulting synthetic lubricant may be reacted with an additional quantity of a thiol with the same or diil'erent thiol to form a product of higher sulfur content and of increased oxidation stability.

It will be understood, of course, that the condensation is aided by providing mixing of the reactants. This may be provided by using various agitating means which are well known in the art. At the reaction conditions, the reactants are readily soluble and homogeneity is easily obtained.

Examples In order to illustrate the prlnciples of this invention, the results of a series of typical, and non-limiting, condensations are set forth in tabu- 6 be noted that the designation "N. N." refers to the neutralization number, which is a measure of the acidity of the oil. I

Styrene used in these condensations contained a a fraction of one per cent of p-tertiary-butyl z'g g g grfi f g ggz g zgg iggz fi catechol, the latter acting as a stabilizer or polyican Instrument (10.). The reactants were figi gm ggg ggh fi ama g charged to the bomb, which was then heated to v the desired temperature for the desired length of By way of illustration the procedure unwed time Thereafter was cooled. and in run 1 Of Table I below, provided in detaiL A charged. The contents of the bomb were vacuum mixture of 336 parts by weight (3 molar prom!" distilled to remove unreacted materials. It should mus) mime 39 mm by weight benoted that the reaction times, recited as "Time, paportlmi) of g 8 8 by s:

' Hours" in Table I, represent the time intervals 67 3 e g 13:

during which the bomb was maintained at the 15 was f i 1 a s a m g' {3 desired temperature, and do not include the time er can Inst! r 9 intervals necessary to heat the bomb and its conbomb head was secure approximately 1500 tents to the desired temperature, and do not inper square inch of nltmgen was Pressured mm clude the time intervals. necessary to cool the the bomb to (meek for The pressure bomb after heat wthe bomb has been discom then released. the system was again closed and til-lued. The condensation products discharged I the bomb was heated in the 01 from the bomb, or other reaction vessel, were dis- 1V2 hours and held at that temperature for ten tilled and filtered, as in the runs shown in Table' hours- During the Teactmn 1 To the condensation products from lbs. per Square inch developed. cooling the the distillate fractions thereof, the refined oils bomb to room p ature, (70 F.), during a are identified as residual oils. The latter term Per 10d of fibmlt three hours, the reaction Pmduct identifies the oils from which uhreaeted matewas discharged into a la and pped under rials and products of intermediate boiling range reduced p s r Hz) to a liqui temperhave been separated. ature of 420 F. and a vapor temperature of 345 F. All of the tests and analyses to which the re- A quantity, 118 parts by weight, of residual oil sidual oils in Table I were subjected are well was obtained and was filtered through a thin coat known standard tests. In this connection, it will of a diatomaceous earth filter aid (Super Flltrol) Table 1 Reaction Conditions Olefin Styrene Mercaptan Reierence Temp. Time Max. Press. P P i i Name Moles l3? Moles Name 3? Moles F P I 6' Weight Weight weight CONDENSATION or OLEFINS WITH STYRENE AND ALKYL MEROAP'IANS I Run:

1. Octane-l 336 s 39 0. 315 0 0. 001 601 10 200 Octane-2 330 a s9 0. 315 0 0.067 002 10 150 Z-Ethylhexene-l. 3 30 0.315 0 0.067 002 10 200 3 as 0.315 0 0.001 504 10% 100 s 30 0. 315 e 0. 001 59s 10 a00 s 39 0.515 0 0.001 s 10 a 39 0.315 a -0.001 100 3 800 3 39 0. 315 0 0. 067 150 a 150 3 10 0.090 t 0. 001 053 10 200 s 39 0.315 0 0.051 052 10% 000 OLEFINS WITH STYRENE AND AROMATIC MEBCAPTANB 0 0. 054 001 1034 l00 0 0. 054 041 lo 600 do o 0.054 054 9% 150 14 Product of Run l3 30 0. 273 605 5% (100 CONDENSATION or OLEFINS WITH STYRENE AND HETEROCYCLIO MERCAPTANS Run:

15 Decene-l 420 s 30 0.003 601 10% also 16 Product 0! Run 15-- 220 0.011 600 5 150 420 3 30 0.112 509 10 300 420 a as 0.011 04s 10 450 l 104 l s05 10 200 840 6.0 12 600 10% 400 CONDENSATION or OLEFIN WITH BUTADIENE AND ALKYL MERCAPTAN Run 21 Decene-l 420 a 21 0.5 N-butyl o 0.061 050 m4 620' See footnotes at end of table.

Table I-Continued Residual Oil Reference Weight 01000 K. v. a x. v. r001 Parts by rel-00110 Poin 100 210 F. v I. Point N. N. wei Yield r 00 c0 F.

CONDENSATION or 01.001100 WITH S'IYBENE AND ALKYL MERCAPTANS 110 01 22 02 4. 00.0 -00 o. 2 0. 0120 0 00 40 11.0 00.24 4.00 42 -00 o. 1 0.0152 0.01 5.2 05. 01 4.00 0 50 124 04.45 5.20 000 -00 0.2 0.0111 0.04 112 24. 1 11. 11 0. 10 110. 4 -00 0. 1 0. 0500 0. 01 150 00.0 21.11 4.20 120.4 -00 02 0.0550 0.10 114 01.4 1000 0.00 125.1 -20 0.2 00545 0.20 v 121 20- 2410 4.01 114.5 -5 0.2 0.0044 010 101 00 2400 4.10 120.0 -00 0.2 0. 0400 0.20 11 10 0 22 4.50 100 4 -00 0. 2 0. 0102 1.01

CONDENSATION or OLEFINS wrrn BTYRENE AND'ABOMATIO MERCAPTANS 15. 00 0. 55 111. 0 -00 0. 1 o. 0001 0.10 22.01 4.00 110. 1 -0o 0. 1 0. 0020 0. 20 20. 10 440 120.1 -0o 0.1 0.0501 0.10 2012 5.00 111.5 -5 0.0 0.0000 0.12

OLEFINS WITH STYRENE AND rm'rnaocyomo MEROAPTANS CONDENSATION or OLEFIN wrrn BUTADIENE AND ALKYL MERCAPTAN Run 21 151 00.4 25. 14 5. 04 141 -00 Nil 0. 0400 0. 12

1 From 390 g. of reaction product. Remainder used in run 14. From 228 g. of reaction product. Remainder used in rim 15. I Weight of total reaction product from the indicated run.

olefin, oc'tene-l, reacts to form a substantially greater yield of a superior oil than does either the corresponding 2-olefin and the corresponding branched-chain ,octene. The oil product obtained by octene-l has a. significantly higher V. I. than to three hours, are most satisfactory in that oil products of high viscosity index and low pour point are formed in relatively high yield. These salient features are revealed in the following tabulation.

the oil products'jrom octene-2 and z-ethylhex- 1100051011001 Residual on ene-l. This is summarized in the following tabufilm! lation: Run No. Yi m K v e Pour 229" f g Weight 210 F? v 1 Point, Percent 00.

Residual 011 4 504 10% 12.4 5.20 00.0 00 02 0 02-: 20 mm OM11 r1010, K. v. 100 0 0114 0100 12511 -20 Weight 210 1 v. 1. 150 0 20.0 4.01 114.5 -5 Percent 00.

1 Octene-l 01.0 4.10 00.0 2..- Octane-2 11.0 4.00 42 0 Z-ethylhexene-l 6.2 4.39 0 A comparison of runs 6 and 9 indicates that as the proportion of styrene is increased the yield of residual oil increases without materially detract- Buns 4-8 show the influence of reaction temperature and time upon the condensation of decene-Lstyrene and n-butyl mercaptan. Temperatm es of about GOO-750 F. with times of ten ing from the character of the oil product. This feature is shown in the following tabulation wherein a. blank run is shown for the condensation of decene-l and n-butyl mercaptan in the absence of styrene; in the blank run, the proportions of mono-olefin and mercaptan are the same as in runs 6 and 9.

captan structure with the properties of the oil products. The straight chain structure of n-butyl mercaptan, in contrast to the branched-chain structure of tertiary-butylmercaptan, appears to have a salutary eflect upon the yield and V. I. In addition, the oil product obtained from the n-butyi compound has a lower sulfur content. These features are revealed in the following tabulation: 4

Residual oll Mercap' Run No m1 Yield, K.y.@ s w 1 M 3 1 210 F., v.1. g i

o n-ButyL 33.6 4.29 120.4 0.18 t-ButyL. 16.0 4.68 100.4 1.01

Oil products obtained with aromatic mercaptans are shown in runs 11-14. It will be noted that run 14 involves reaction of additional thiophenol with the reaction product of run 13. Additional sulfur is introduced without affecting the characteristic properties of the oil.

A heterooyclic mercaptan, thiophenethiol, is shown in runs 15-19. A further illustration of reacting the olefin, vinyl aromatic and mercaptan under optimum conditions to obtain a residual oilor high yield, high viscosity and high viscosity index, and thereafter increasing the sulfur content with the additional mercaptan, is shown by runs 15 and 16. This procedure is preferred when producing oil blending stocks of relatively high sulfur content, where viscosity index and pour point of the oils blended therewith are improved by virtue of the high viscosity index and low pour point of the synthetic blending stocks. Runs 15, 17 and 19. illustrate the direct of the quantity of thiol used in the condensation. When the molar proportion of thiol is increased such that the olefin:styrene:thlol ratio is 1 1:1, the viscosity index of the oil product falls on considerably, specific gravity increases and the sulfur content is increased greatly. The oil product of run 19, finds utility as a lubricant in operations wherein high viscosity index is not required and also finds utility as an oil addition agent for lubricating oils.

Run 20 is shown herein to demonstrate the difference between an oil product obtained by condensation of a l-olefln and a vinyl aromatic compound in the absence of a thiol, and an oil product obtained with a thiol. An effective comparison is provided by runs 5. 11, 15 and 20. It will be clear that the oil obtained in run 20, in which no thiol was used, has excellent viscosity index and rate of 10 liters per hour. The test tube is heated 10 pour point properties, but has an undesirably high cloud point, 60' F. In contrast, the oils of runs 5, 11 and 15 have low cloud points. Emphasizing this relationship, the salient features of these runs are tabulated below:

Mercaptan Run Deoene-i, Styrene, ig No 1 e M Cloud ropn. ropn. 0 er Name Propn. Pt., "F.

20 6 0. 75 None- +00 5 3 0. 375 n-Butyl.. 0. 007 20 11 3 0.375 Thlo henol... 0. 054 -28 15 3 0. 375 3-tlhli oplleno- 0.008 34 Residual Oil p one 0 Run Molar Yield, K. v. s,

Propn Wei ht 210 F V. I Wei ht Per ent Cs. 1 Per eat 20 0-1 63.6 4.80 131.3 1s 0. 00s as 4.11 130. 1 o. 25 17 0.112 14.0 4.08 104.1 6.38 19 l. 0 30 0. 59 30. s 19. 9-1

It will be seen that the advantages obtained by the use of thiols are at the expense of yield, but it must be kept in mind that the oil obtained without a thiol is characterized by a poly-styrene cloud and is not usable as such.

Run 21 illustrates an excellent synthetic oil obtained with butadiene as the polyolefinic reactant.

That the residual oils of this invention have excellent stability is shown by results of a catalytic oxidation test, the results being shown below in Table II. This oxidation test reveals the stability of oils toward catalytic oxidation.

The test oil, 25 00s., is placed in a 200 x' 25 mms. test tube with 15.6 square inches of sand-blasted iron wire; 0.78 square inches of polished copper wire, 0.87 square inch of polished aluminum wire, and 0.167 square inch of polished lead plate. Dry air is passed through the sample of oil at a.

at 260 F. for 40 hours in an aluminum block bath. The results reported at the end of the test are: neutralization number (N. N.) percent viscosity increase at 210 F. sludge and lacquer; lead weight loss (in milligrams); and appearance of copper. The oil is compared with a reference oil of similar viscosity and is rated on the basis of viscosity increase, N. N. increase, sludge and lead weight loss. A maximum of 3 demerits is assigned to each factor rated. The sum of the demerits for an oil is called the stability number and ranges from'l to 12. The reference mineral oils, solvent-refined Pennsylvania oils, hav a stability number of 6 to 7.

Table II.-Oa:idation stability of oils 6 Cent Slnd Pb Lo Stabilit on N. N. 210 F Visooslt Copper Coil Y cl more: Tube Mg. Number 10W Mineral Base Stock L... 16 12.91 125 N11 236 6 or 7 un20 as 0.44 90.2 Nil Dull Coupon--. ma 0 PRODUCTS FROM CONDENSATION OF OLEFINS WITH STYRENE AND ALKYL MERCAPTANB Run 6 .8 3.2 Run 10 .0 7.4

Nil.

NIL.-."

PRODUCTS FROM CON DENSATION OF OLEFIN S WITH STYRENE AND AROMATIC MERCAPTANB PRODUCTS FROM CONDENBATION (1;

Nll 251.3 5 N11 Brown Shim... 243.2 7 Nil 159 2 OLEFINS WITH STYRENE AND HETEROCYGLIC EROAPTANS Run 15 5.0 4. 97 20.9 NI] Brown Staln. 242.6 3 Run 16.--- 0.8 4. 62 4.6 Ni. DarkBrown.- 36. 6 0 Run 17 1.1 4.36 6.8 N Black Stain. 36.3 0 Run 18 10.8 7.07 53.6 N Brown Stain 245.8 6 Run 19 27 in 10W Base Stock 1.8 6.27 10.1 N l Brassy 18.8 0 Run 19.6 o In 10W Base Stock 15.0 10.08 71.1 N d 199.1 4

PRODUCT FROM OONDENSATION OF DECENE-l WITH BUTADIENE AND N-BUTYL MERCAP'IAN Run 21 12. 5 11. 86 134 Nil.

1 Average values.

The results presented in Table 11 above, reveal that a solvent-refined Pennsylvania mineral oil, SAE 10W mineral oil base stock, which is considered in the art as a relatively stable mineral oil, has a stability number of 6-7 in the test described above. Similarly, the residual oil of run 20, obtained by condensation of decene-l and styrene, without a thiol, has a stability number of 6; this isthe residual oil having a cloud point of +60 F. In contrast, the residual oils of runs 6 and 10, obtained by condensation of decene-l with styrene, and with n-butyl mercaptan and t-butyl mercaptan, respectively, are substantially more stable for they have stability ratings of zero. 1 Residual oils of runs 12 and 13, obtained with thiophenol were less stable than those obtained with the butyl mercaptans, but were as stable as the mineral oil base stock. Stability numbers for with more thiophenethiol was resorted to, an improvement in stability was realized (zero as compared with 3). This is shown by the oils of runs 15 and 16. In run 17 a larger amount of thiophenethiol was used in the initial reaction than was used in run 15, and a stability number of zero characterized the product. In run 19,

still more thiophenethiol was used. The mineral oil base stock was effectively stabilized when 2% of the residual oil of run 19 was incorporated therein; however, 0.5 per cent of this residual oil was insuflicient for this purpose. It will be recognized, therefore, that in all instances the new synthetic oils are equal to or better than an SAE 10W Pennsylvania motor oil in every respect.

As will be evident from the data presented above in Tables I and II, the condensation products of this invention are highly desirable lubricants per se. They are also of considerable value as blending agents for other lubricating oils. In view of the inherent stability of the synthetic oils, they impart stability to the oils with which they are blended. So also, they 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 turbineengines. When so blended, the synthetic oils may comprise the major proportion of the final blended oil, or may even comprise a minor proportion thereof. For example, although used only in the amounts of the order of 1-10 per cent, the synthetic oils improve the stability of mineral oils, such as SAE 10 and 20 Pennsylvania type oils.

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 anantioxidant, a detergent, an extreme pressure agent, a foam suppressor, a viscosity index (V. I.) improver, etc. Antioxidants are wellknown in the art, and are generally characterized by phosphorus, sulfur, nitrogen, etc. content; representative of such materials is an oil-soluble, phosphorusand sulfur-containing reaction product of pinen and phosphorus pentasulflde. 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 salt 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 chlornaphtha xanthate. Silicones, such as dimethyl silicone, may be used to illustrate foam suppressing comabout 0.001 to about one molar proportion of a thiol.

positions. 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 oils.

It is to be understood that the foregoing de-. scription 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 method of preparation of a viscous oil, which comprises: condensing, at a temperature between about 500 F. and about 800 F. for a period of time sufficient to etlect condensation,

one molar proportion of a normal, alpha monoolefin having from five to eighteen carbon atoms per molecule, from about 0.01 to about one molar proportion of a conjugated olefinic hydrocarbon and from about 0.001 to about one molar proportion of a thiol.

2. The method of claim 1 wherein the temperature is between about 600 F. and about 750 F.

3. The method of claim 1 wherein the monoolefin has from eight to twelve carbon atoms per molecule.

4. The method of claim 1 wherein the conjugated olefinic hydrocarbon is an alkenyl-substituted aromatic hydrocarbon.

5. The method of claim 1 wherein the conjugated olefinic hydrocarbon is a vinyl-substituted aromatic hydrocarbon.

6. The method of claim 1 wherein the thiol is an alkyl thiol.

7. The method of claim 1 wherein the thiol is an aryl thiol. 1

8. The method of claim 1 wherein the thiol is a heterocyclic thiol.

9. A new composition of matter comprising, a sulfur-containing condensation product obtained by: condensing, at a temperature between about 500 F. and about 800 F. for a period of time sufficient to effect condensation,v one molar proportion of a normal, alpha mono-olefin having from five to eighteen carbon atoms per molecule,

from about 0.01 to about one molar proportion of a conjugated olefinic hydrocarbon and from 10. The composition of claim 9 wherein the temperature is between about 600 F. and about 11. The composition of claim 9 wherein the mono-olefin has from eight to twelve carbon atoms per molecule.

12. The composition of claim 9 wherein the conjugated olefinic hydrocarbon is an alkenylsubstituted aromatic hydrocarbon.

13. The composition of claim 9 wherein the conjugated olefinic hydrocarbon is a vinyl-substituted aromatic hydrocarbon.

14. The composition oi claim 9 wherein the thiol is an alkyl thiol.

15. The composition of claim 9 wherein the thiol is an aryl thiol.

16. The composition of claim 9 wherein the thiol is a heterocyclic thiol.

17. A sulfur-containing viscous oil of lubricating viscosity obtained by: condensing about 45 molar proportions of n-octene-l with about 5.5 molar proportions of styrene and with one molar proportion of n-butyl thiol at about 600 F. for about ten hours.

18. A sulfur-containing viscous oil of lubricating viscosity obtained by: condensing about 45 molar proportions of n-decene-l with about 5.5 molar proportions of styrene and with one molar proportion of t-butyl thiol at about 650 F. for about ten hours.

19. A sulfur-containing viscous oil of lubri cating viscosity obtained by: condensing about 375 molar proportions of n-decene-1 with about 50 molar proportions of styrene and with one molar proportion of 3-thiophenethiol at about 600 F. for about ten hours.

WILLIAM E. GARWOOD.

JOHN W. BROOKS.

ALEXANDER N. SACHANEN.

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

UNITED STATES PATENTS Certificate of Correction Patent No. 2,500,672

WILLIAM E. GARWOOD ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 3, line 19, for ankenyl read glkenyl; columns 7 and 8; Table I, tenth column thereof, opposite Run 17 for 0.936 read 0.9036 columns 11 March 14, 1950 and 12, Table 11, second column thereof, opposite Run 12, for 12.3 read 7 and that the said Letters Patent should be read as corrected aboue, so that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 19th day of December, A. D. 1950.

THOMAS F. MURPHY,

I Assistant Commissioner of Patents.

Claims (2)

1. THE METHOD OF PREPARATION OF A VISCOUS OIL, WHICH COMPRISES: CONDENSING, AT A TEMPERATURE BETWEEN ABOUT 500*F. AND ABOUT 800*F. FOR A PERIOD OF TIME SUFFICIENT TO EFFECT CONDENSATION, ONE MOLAR PROPORTION OF A NORMAL, ALPHA MONOOLEFIN HAVING FROM FIVE TO EIGHTEEN CARBON ATOMS PER MOLECULE, FROM ABOUT 0.1 TO ABOUT ONE MOLAR PROPORTION OF A CONJUGATED OLEFINIC HYDROCARBON AND FROM ABOUT 0.001 TO ABOUT ONE MOLAR PROPORTION OF A THIOL.

17. A SULFUR-CONTAINING VISCOUS OIL OF LUBRICATING VISCOSITY OBTAINED BY: CONDENSING ABOUT 45 MOLAR PROPORTIONS OF N-OCTENE-1 WITH ABOUT 5.5 MOLAR PROPORTIONS OF STYRENE AND WITH ONE MOLAR PROPORTION OF N-BUTYL THIOL AT ABOUT 600*F. FOR ABOUT TEN HOURS.