Solid anti-friction devices – materials therefor – lubricant or se – Lubricants or separants for moving solid surfaces and... – Heterocyclic ring compound; a heterocyclic ring is one...
Reexamination Certificate
1991-08-29
2001-11-06
Johnson, Jerry D. (Department: 1111)
Solid anti-friction devices, materials therefor, lubricant or se
Lubricants or separants for moving solid surfaces and...
Heterocyclic ring compound; a heterocyclic ring is one...
C549S017000
Reexamination Certificate
active
06313075
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to improved lubricant compositions comprising alkylated thianthrene lubricant fluids alone or in combination with synthetic or mineral oils, and to mineral or synthetic lubricant oil or hydrocarbyl or hydrocarbloxy fuel compositions containing minor amounts of said alkylated thianthrenes as multifunctional additives therefor.
2. Description of Related Art
Polyphenyl sulfides are known and have been used as lubricants/additives in special applications, Polyphenyl sulfides suffer from very high cost due to difficult synthesis and have poor low-temperature properties.
Incorporation of linear alkyl groups into diphenyl sulfide eliminates both of the above problems and provides a novel, relatively inexpensive lubricant having excellent low-temperature properties. The use of these adducts as a lubricant or lubricant additive in either mineral or synthetic lubricants has been recently disclosed as noted in one of the above copending applications.
The principal limitation of getting monoalkylated fluids of diphenyl sulfide using octadecene or lower olefins having greater than 5 cSt viscosity at 100° C. limits end use applications. However, alkylation of thianthrene with hexadecene provides a monoalkylated adduct having a viscosity of >12 cSt. This opens a wider range of application areas for this novel lubricating fluid.
The preparation and use of alkylated thianthrenes as a new class of lubricating fluids is disclosed in the instant application. These fluids have the advantages of alkylated diphenyl sulfides in that the polar sulfur provides excellent additive solubility and good lubricating properties.
BRIEF SUMMARY OF THE INVENTION
This application is directed to novel lubricant compositions comprising from about less than one percent to about 100% of alkylated thianthrenes as disclosed herein and to mineral and synthetic lubricants and fuels containing minor proportions of the disclosed thianthrenes as multifunctional additives.
The products obtained from the reaction of a linear olefin and thianthrene in the presence of specific zeolite catalysts are unique not only in composition and structure but in utility. Part of the uniqueness may be derived from the specific reaction over zeolite catalysts; generally, they have a higher VI at a given viscosity. The incorporation of various alkyl groups into the thianthrene structure provides compositions of different viscosity and low temperature viscometrics.
The thermal stability of these alkylated thianthrenes is excellent and believed to be improved over materials of branched structure due to the facility for carbon-carbon bond breaking in the latter materials.
These unique lubricants exhibit beneficial properties from the unique reaction of olefin with the thianthrene structure in such a way as to remain predominantly linear. This is a direct result of the catalytic reaction. This combination provides for the novel structural class disclosed here. The use of these compositions of matter as either functionalized alkyl thianthrene lubricant fluids or lubricant additives is believed to be novel.
The use of these adducts as a lubricant or lubricant additive in either mineral or synthetic lubricants is unique and provides improved properties and performance benefits due to inherent synergism. It is expected that the performance benefits will include antifatigue, antispalling, antistaining, antisquawking, improved additive solubility, improved load carrying/bearing, extreme pressure, improved thermal and oxidative stability, friction reducing, antiwear, anticorrosion, cleanliness improving, low- and high-temperature antioxidant, demulsifying, emulsifying and detergency properties.
It is therefore an object of this invention to provide improved compositions comprising novel lubricant compositions comprising the alkylated thianthrenes in accordance with the invention and novel lubricant and fuel compositions containing minor proportions of said thianthrenes as additives.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Broadly, the novel class of hydrocarbon products of the present invention can be characterized as adducts of a hydrocarbyl substituent precursor, which can contain one or more olefin groups, and a thianthrene. The hydrocarbyl substituted group can contain from C
3
-C
500
, preferably C
6
-C
50
and most preferably C
8
-C
18
The hydrocarbyl group can optionally contain S, N, O, P and/or F. The hydrocarbyl group can be alkyl, alkenyl, alkynyl, arylalkyl, aryl, aliphatic, cyclic, linear or branched. Substitution can be on one or more positions of the aromatic rings, with alkylation on either or both rings.
The preparation of these novel compositions may be by means of a thermal or catalytic addition reaction. The exact mechanism of the reaction is not important to the purposes of this invention, so long as the hydrocarbyl group becomes attached to the thianthrene described herein.
One preferred method of reaction between the hydrocarbyl substituent precursor and the thianthrene is the combination of these reactants in the presence of specific zeolite catalysts. Non-limiting examples are Octacat® USY, ZSM-12 and MCM-22. This reaction is affected at temperatures ranging from ambient to 350° C., preferably from 100-250° C. and most preferably from 180-240° C. over a period required to produce desired conversion of reactants to product. Optionally, the reaction can be performed in a batch or semi-batch mode by continuous or partial addition of the catalyst or hydrocarbyl group to the thianthrene. Catalyst can be used at levels ranging from 1 gram/mole of aromatic to 50 grams/mole of aromatic, and most preferably from 10-30 gram/mole of aromatic.
In general, the production of alkylated thianthrenes is favored by the use of zeolite catalysts such as zeolite beta or zeolite Y, preferably USY, of controlled acidity, preferably with an alpha value below about 200 and, for the best results, below 100, e.g., about 25-50.
The alpha value of the zeolite is an approximate indication of the catalytic cracking activity of the catalyst compared to a standard catalyst. The alpha test gives the relative rate constant (rate of normal hexane conversion per volume of catalyst per unit time) of the test catalyst relative to the standard catalyst which is taken as an alpha of 1 (Rate Constant=0.016 sec−1). The alpha test is described in U.S. Pat. No. 3,354,078 and In J. Catalysis, 4, 527 (1965); 6, 278 (1966); and 61, 395 (1980), to which reference is made for a description of the test. The experimental conditions of the test used to determine the alpha values referred to in this specification include a constant temperature of 538° C. and a variable flow rate as described in detail in J. Catalysis, 61, 395 (1980).
Optionally, the products of this invention can be prepared by reaction of the hydrocarbyl substituent precursor with thianthrene in the presence of AlCl
3
and other proton or Lewis acids as described in G. A. Olah's “Friedel-Crafts and Related Reactions”, Vol. I, 1963, Interscience Publishers.
The alkylated thianthrenes produced by this process may be represented generally by the structure:
where R
1
, R
2
or R
3
may be H, alkyl, alkenyl, alkynyl, aryl, alkylaryl, cyclic, linear or branched as previously described;
and/or where R
1
, R
2
or R
3
can contain S, N, O, P and/or F;
and/or where R
1
, R
2
or R
3
are linked to form a cyclic structure.
The hydrocarbon compositions of the present invention relate to improved thermally and oxidatively stable fluids. These may be used optionally as liquid lubricants or in liquid lubricant compositions, and as solid lubricants or in solid lubricant compositions including greases, such as polyurea, lithium carboxylate or clay-thickened greases.
These hydrocarbon compositions may also be used in combination with additives, for example, antioxidants, EP/antiwear agents, inhibitors, detergents and dispersants, and viscosity index improvers. Non-limiting examples of antioxidants include phenols which can be
Rowe Carleton N.
Rudnick Leslie R.
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