US2773038A - Lubricants - Google Patents

Description

United States Pate t LUBRICANTS No Drawing. Application November 20, 1951, Serial N0. 257,410

18 Claims. (Cl. 252-48.8)

This invention relates to new and improved lubricants. In one aspect this invention relates to improved lubricating oils containing selected sulfun'zed compounds as addition agents. In another aspect this invention relates to the preparation of materials having particularly utility as mineral lubricating oil addition agents.

At the present time it is common practice to enhance or modify certain of the properties of lubricating oils through the use of additives or improvement agents, to render the oil serviceable over the adverse conditions encountered, when employed in internal combustion engines such as automotive, aircraft, and diesel engines. Our invention is concerned with new lubricating oil addi- Iives or improvement agents, which when incorporated with a mineral oil employed as a lubricant in an engine of the internal combustion type, impart valuable improvements to the oil, particularly as regards corrosion inhibiting properties, and increased resistance of the oil to oxidation.

An object of this invention is to provide new lubricating oil compositions. Another object is to provide new mineral oil addition agents. Another object is to provide for an increase in the anticorrosion and antioxidation characteristics of a mineral lubricating oil. Another object is to provide a class of mineral lubricating oil addition agents, which when incorporated with a mineral lubricating oil in service in an internal combustion engine of the type above described, greatly reduce, :the corrosive action of the oil on engine bearing parts, and increase its resistance to oxidation. Other objects will be apparent to those skilled in the art in the light of the accompanying disclosure. I

In accordance with our invention we provide as new lubricant compositions, a mineral lubricating oil containing in solution a minor proportion of a sulfurized diarylalkane. Our invention is based on our discovery that diarylalkanes can be sulfurized to form a product material, which when dissolved in a mineral lubricating oil improves the resistance of the oil to oxidation and inhibits corrosive action of the oil on engine parts in contact therewith.

The sulfurized diarylalkaue addition agents of our invention are those produced by sulfurization of diarylalkanes, when employing sulfur monochloride as the sulfurizing agent either non-catalytically or in the presence of a catalyst, as described hereafter. Diarylalkanes to be sulfurized to produce our addition agents contain the two aryl groups preferably attached to alkane carbon atoms either adjacent each other or separated by no more than one carbon atom. The aryl groups of the diarylalkane can be the same or different and are comprised of phenyl, naphthyl, anthryl and phenanthryl radicals, substituted or unsubstituted.

The diarylalkane to be sulfurized can be produced in any desired manner. One preferred method involves the alkylation of an aromatic compound such as benzene, naphthalene, anthracene, phenanthracene, or such are- 2,7710% Patented Dec. 4, 1 956 2 matics substituted, as for example toluene, xylene, phenol, dimethyl naphthalene, diamyl naphthalene, dioctyl naphthalene, di-tert-dibutyl anthracene, di-isoamylphenanthrene, tri-tert-butyl phenanthrene, methyl-tertbutylnaphthalene, ethyldodecyl benzene, cumene, and the like, and particularly long-chain alkyl aromatics, with conjugated diolefins often, containing from 4 to 6 carbon atoms, as for example, 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2-methyl-l,3-pentadieue, and the like. Other diolefins particularly representative of those that can be alkylated with an aromatic to produce, the diary!- alkane to be sulfuiized include, conjugated dodecadiolefins, viz. 1,3-, 2,4-, 3,5-, 4,6- and 5,7-conjuated octadienes, conjugated heptadienes, or such dienes alkyl substituted. Such an alkylation can be etfected under any appropriate alkylating conditions and in the presence of a'suitable catalyst as, for example, hydrogen fluoride, boron fluoride, a boron tiifluoride-water complex, a complex of boron trifluoride with aqueous hydrogen fluoride, aluminum chloride, and the like, the specific alkylating temperature and time conditions being characteristic of those generally employed in conjunction with the particular ice alkylation catalyst employed.

The sulfurization of the diarylalkane is conducted, employing sulfur monochloride as the sulfurizing agent, generally at a temperature within the limits of 20 and 110 C., and preferably within the narrow range of about 40 and 60 C. However, the rate of sulfurization reaction varies considerably depending on the particular substituents on the aryl radical, if any and on their position. For example, those diphenylalkanes in which the para position of the phenyl group is occupied, sulfurize much more slowly than when the para position isfree. In such a case, i. c. When the para position is substituted, a higher temperature is generally preferred, the optimum level likely being between about 60 and 110" C., so as to effect the desired sulfurization in a reasonable length of time. However, the rate of the sulfurization can be increased also by etfecting the reaction in the presence of a suitable catalyst, such as zinc dust. Accordingly, if desired, we can increase the rate of the sulfurization by increasing the sulfurization temperature, or by the use of a suitable catalyst, or both. If time is too short, conversion is low; if too high, some of the desired oil soluble product is converted into insoluble material. The optimum reaction time will depend on other reaction vari: ables such as the mol ratio of sulfur monochloride to the diarylalkane, presence and character of a catalyst, temperature and the like. The optimum timeff may be determined by routine test. For the sulfuriz'ation condi tions illustrated in the examples, a sulfurization time of from 30 to minutes ispreferable.

The addition agent of our inventionappears to be formed by coupling of sulfurized monomers and non-sulfurized monomers (the selected diarylalkane) together with sulfur to form the resulting sulfur-containing polymer. In carrying out the sulfurization it is important to effect the careful control of the sulfurization conditions' to form highest yields of oil-soluble sulfur containing product. Accordingly it is important to effect the sulfurization within the reaction time above described, 'by carefully selecting the requisite temperature level, and

if needed, a suitable catalyst, as well as to employ' a' ;S 5. I$ etest?! .9 ha.. .!in latt sa iaaatqnetties, and of suitable gradeajnd viscosity can be employed in compounding our impfdved lubricating oil composiip rzeariit etst qd hasetnzate alset negal, .having ayiscqsityat .F as-1owas45 Q h seii i p the composibje te df All ough thelcoiicentration of ed ll' not gen r -i11y',ex eea l0 ons jcanbe jemploye'd, i'f de- :Ex mp j- 1Xylene, in troducedinto an alkylation zone with 1,3- but adieriejna'mol ratio to maqienejor approximately 2 1' 631.7 pounds of total-reactants was 'alkylat'ed with the butadi'e ne at atmosphericpressure and atateinperaire-c560 to=70 FLiiii the'prese'nceof aBF3 HF H2O catalyst to form dixylylbutane. Thecatalyst was-prepared by saturating 47 percent aqueous HF with BFs. The catalyst volume was IOpercent of the total yolume of catalyst'au'd'reactants; The alkylation was a batch reaction,"- and the purified product-had-a boiling range of 624m 660 F. (atmospheric pressure) and a specific gravity at 1 5 m s ro sqfiwmaasfllp i w added t 18 moles of th urijed dixylylbutane, .together with app iliirj iately grams of zinc dust, employing 300 cc. 1 Zane ;d iljient. Previous experiments showed that i t i e w h ben n and ul m m chloride piesericeof zinc, below a temperature of 70 f t n a mixture .was ,warnied ,to 45 thus start iigt U cho and waslhen cooled to v to C. whe'fEmiSstof the ieactioh was permitted to take t place. Toward -the end .of the reaction {the temperature was "dlto'ffl 1C1 hereacti ori admixture contained an s'iof sulfur ;morioch l6ride, a major proportion of j'liilil was segmgted rram' sulfurized 'lpro'du ct, ,togetli r. W; hQthe Ibeniene' diluent byfvac'uum distillation,

ssesfor the remoyal of elementary sulfur from its adfixture with a sulfurized'hyd'ocarbon compound emplayin Silitii gelf llpoii washingwith fli) percent benzene in pentane, the sulfurized dixylylbutane was obtained .ttea t ast iame lhi tmateat ailatesim zi hst lstea was boiled with barium oxide for three hours. was added to distill out the. residual toluene and then the xylene was distilled. The product was stripped with gas found upon analysis to c o ntai n 12:03 weight percent sulfur, 0.10 weight percent ash and 1.37 weight percent chlorine, and was tested asdescribed in Example 3.

Toluene was introduced into an allgylatign zone,;,with 1,3-butadiene in a mol ratio to butadi ne of approximately' 10:1 (2565 pounds of :total reactants and alkylated with the butadiene at atmospheric pressure and at a H2O catalyst, to form ditolylbutane. The catalyst was prepared by making a saturated solution of BFa in water. Th

i its l it t -p tas t s i h u 30 msof i .dus't, asainengp oy n b zen a diluent." Iii ereactiontemperatureiwas.maintained th 5 C for aboiit one'hour. Thetemperature towardthe he eacti oji l ;.was raised .to 7.0IC. Thefreactiop awed xq i v it 6fi f9 l9fi,

p rated from the sulfurized prod i t at unh fiulfurind PRQ JP Example 3 q i nqit --i Base- Lubricating Oil, Weight Percent 100.0 99. 5

Sulfurized dixylylbntane, W t'Perpent 0.0 0.5 sulfurized ditolylbu e, W ght 'Percent .-Purifiedtproduet.of,Example 1.

fli a flt srqqe tQFEWPW- .hc e..compo i. ions were evaluated. in .-m9untcd-sing1e ylin er ;H 2 La son t st engine. Thetc psrf rmed consisted inrplacing BOOgrams of the composition in the Xylene rt .iLofwhiizh, together .withdhhenzgge a crankcaseofthe singlet cylinder Lauson 1(gaso1ine).engine,

The bearing weight loss, in milligrams, encountered in each test was as follows:

It will be seen from these data that the addition of a relatively small proportion of an improvement agent of our invention, to a typical crankcase lubricant, decreases the bearing weight loss to a satisfactory low value.

While the invention has been described in connection with a present, preferred embodiment thereof, it is to be understood that this description is illustrative only and is not intended to limit the invention.

We claim:

1. As a new composition, a mineral lubricating oil containing an amount suflicient to impart antioorrosion properties thereto, of a product of sulfurization of a diarylalkane containing from 4 to 12 alkane carbon atoms obtained when employing sulfur monochloride as the sulfurizing agent.

2. A lubricating oil composition comprising a mineral oil having a viscosity index of at least 50 and containing an amount suflicient to impart anticorrosion properties thereto, of a product of sulfurization of a diarylalkane containing from 4 to 12 alkane carbon atoms, obtained when employing sulfur monochloride as the sulfurizing agent.

3. The composition of claim 2 wherein said diarylalkane is a diphenyl alkane.

4. The composition of claim 3 wherein said diphenylalkane is dixlylbutane.

5'. The composition of claim 3 wherein said diphenylalkane is ditolylbutane.

6. A lubricating oil composition comprising a mineral lubricating oil containing from 0.1 to percent by weight, based on said composition, of a product of sulfurization of a diarylalkane containing from 4 to 12 alkane carbon atoms obtained when employing sulfur monochloride as the sulfurizing agent.

7. The composition of claim 6 containing from 0.1 to 3 weight percent of said sulfurized diarylbutane.

8. A lubricating oil composition comprising a mineral lubricating oil containing from 0.1 to 10 weight percent of a product of sulfurization of diphenylbutane obtained when employing sulfur monochloride as the sulfurization agent.

9. A lubricating oil composition comprising a mineral lubricating oil containing from 0.1 to 10 Weight percent of a product of sulfurization of ditolylbutane obtained when employing sulfur monochloride as the sulfurization agent.

10. As a new composition, a mineral lubricating oil containing an amount sufiicient to impart anticorrosion properties thereto, of a product of sulfurization of a diarylalkane containing from 4 to 12 alkane carbon atoms obtained when employing sulfur monochloi'ide as the sulfurizing agent.

11. As a new composition, a mineral lubricating oil containing an :amount sutficient to impart anticorrosion properties thereto of a product of sulfurization of a diarylalkane, obtained when employing sulfur monochloride as the sulfurizing agent, said 'diarylalkane having been prepared by the alkylation of an aromatic hydrocarbon With a conjugated diolefin hydrocarbon containing from 4 to 12 carbon atoms in the molecule, and said sulfurization having been conducted at a temperature in the range of 20-110 C.

12. The composition of claim 11 wherein said diolefin hydrocarbon reactant contains from 4 to 6 carbon atoms in the molecule.

13. A composition of claim 12 wherein said diolefin is 1,3-butadiene and said aromatic hydrocarbon is xylene.

14. A composition of claim 12 wherein said diolefin is 1,3-butadiene and said aromatic hydrocarbon is toluene.

15. As a new composition, a mineral lubricating oil containing an amount sufficient to impart anticorrosion properties thereto of a product of sulfurization of a diarylalkane, obtained when employing sulfur monochloride as the sulfurizing agent, said 'diarylalkane having been prepared by the alkylation of an aromatic hydrocarbon with a conjugated diolefin hydrocarbon containing from 4 to 12 carbon atoms in the molecule, and said sulfurization having been conducted at a temperature in the range of 20-110 C. with sulfur monochloride having been introduced into the sulfurization zone in a mol ratio to said diarylalkane therein in the range of from about 0.5 :1 to 2:1, and for a period of from 30 to minutes. 7

16. A composition of claim 15 wherein said aromatic hydrocarbon is selected from the group consisting of benzene, naphthalene, anthracene, phenanthrene, toluene, xylene, phenol, dimethyl naphthalene, diamyl naphthalene, 'dioctyl naphthalene, di-tert-butyl anthracene, di-isoamyl phenanthrene, tri-tert-butyl phenanthrene, methyl-tertbutyl naphthalene, ethyldodecyl benzene and cumene, and wherein said diolefin is selected from the group consisting of 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2methyl- 1,3-pentadiene, 1,3-dodecadiene, 2,4-dodecadiene, 3,5- dodecadiene, 4,6-dodecadiene, 5,7-dodecadiene, conjugated heptadiene and conjugated octadiene.

17. A composition of claim 15 wherein said sulfurization is eflfected in presence of zinc as a catalyst.

18. A composition of claim 2 wherein said diarylalkane contains said aryl groups attached to alkane carbon atoms, which atoms are separated by no more than one carbon atom.

References Cited in the file of this patent UNITED STATES PATENTS 2,176,632 Magill Oct. 17, 1939 2,244,886 Lincoln et al. June 10, 1941 2,253,228 Cantrell et al. Aug. 19, 1941 2,380,072 Reid July 10, 1945 2,429,691 Johnson et 'al. Oct. 28, 1947 2,439,228 Sturrock et al. Apr. 6, 1948 2,497,138 Rogers Feb. 14, 1950

Claims (1)

1. 2. A LUBRICATING OIL COMPOSITION COMPRISING A MINERAL OIL HAVING A VISCOSITY INDEX OF AT LEAST 50 AND CONTAINING AN AMOUNT SUFFICIENT TO IMPART ANTICORROSION PROPERTIES THERETO, OF A PRODUCT OF SULFURIZATION OF A DIARYLALKANE CONTAINING FROM 4 TO 12 ALKANE CARBON ATOMS, OBTAINED WHEN EMPLOYING SULFUR MONOCHLORIDE AS THE SULFURIZING AGENT.