US20080064616A1

US20080064616A1 - Fuel And Oil Detergents

Info

Publication number: US20080064616A1
Application number: US11/666,258
Authority: US
Inventors: Daniel Weaver; Daneil Szura; Christopher Whewell
Original assignee: Huntsman Petrochemical LLC
Current assignee: Huntsman Petrochemical LLC
Priority date: 2004-10-25
Filing date: 2005-10-14
Publication date: 2008-03-13
Also published as: EP1805282A4; WO2006047091A2; WO2006047091A3; EP1805282A2; CA2584152A1

Abstract

This invention is directed to lubricating compositions which contain detergent-dispersant components derived from substantially linear alkylbenzenes including sulfonates, overbased sulfonates, and salts and esters thereof. Detergents provided by the invention have a low content of the 1-aryl isomers than materials of prior art. In addition, the detergents of the present invention are prepared using alkylbenzene mixtures which have substantially-reduced benzene content over materials provided by the prior art. The invention provides compositions which are useful in formulating lubricants, motor oils, and the like.

Description

TECHNICAL FIELD

This invention relates to a oil-soluble compositions of matter useful as detergent components in hydrocarbon oils useful for a wide range of purposes, including without limitation general lubricants, lubricating oils for internal combustion engines, cutting fluids, emulsions, and dispersions.
More particularly, the invention relates to oil-soluble alkylbenzenes comprising alkyl chains having between about 16 and 30 carbon atoms in which the alkylbenzenes have a low dialkylate content and unique isomer distribution, including their sulfonate and other water-soluble and solubilizable derivatives.

BACKGROUND

The chemical structure and use of linear alkylbenzenes and their derivatives, including their sulfonate derivatives, in the manufacture of laundry detergents is well known. Generally, linear alkylbenzenes are produced by an alkylation reaction (according to one of any well known processes for producing such materials) in which the net result is the appendage of a hydrocarbyl radical to a benzene ring. The source of the hydrocarbyl radical may be a branched or a linear olefin, either an internal olefin or an alpha olefin, and in practice a mixture of substantially linear olefins is typically used, which mixture comprises various olefins having different numbers of carbon atoms per molecule. For the manufacture of laundry detergents, the range of carbon numbers (the number of carbon atoms per molecule of an olefin used) of an olefin mixture used in the alkylation reaction is typically in the range of between about 8 and 15 (inclusive) carbon atoms per molecule, which molecules are sometimes collectively referred to by those in the art as the “detergent range”.
Alkylation of benzene using olefins in the detergent range leads to a reaction product mixture which contains alkylated benzenes having hydrocarbyl radicals of different chain length appended to a benzene Ying, and also contains position isomers of these alkylation products. Thus, a reaction mixture from the alkylation of benzene using detergent range olefins is often complex in makeup.
Of the possible position isomers referred to above, it has been recently discovered that detergents for use in aqueous systems, which are prepared from alkylbenzenes having the benzene ring located at the 2-position on the hydrocarbyl radical possess enhanced detergency and other beneficial properties over the other isomers produced in the alkylation. This is believed in part to be true because the hydrocarbon chain that is appended to the ring extends a greater distance in space in isomers having a phenyl group in the 2-position than the other position isomers, thus providing a molecule having a more volumetrically exposed hydrocarbon chain portion over other position isomers. Among other things, this increased exposure provides increased availability for interaction with hydrophobic materials which are sought to be solubilized in an aqueous medium, when the alkylbenzene also includes a hydrophilic moiety, such as a sulfonate group bonded to the benzene ring.
Detergents useful as components in hydrocarbon oils are often possessive in general of the same properties as detergents useful in aqueous media, that is, their molecules contain both a hydrophilic and a hydrophobic portion. However, in many applications it may be beneficial to employ alkylbenzenes having longer hydrocarbon chains on the benzene ring than those found in conventional detergents, for example to enhance solubility in hydrocarbon oils, or to provide increased compatibility and chemical inertness with respect to other components of the formulation, depending upon the intended use.
The production of sulfonates by reaction with, e.g., SO₃, is well known to those skilled in the art. See, for example, the article “Sulfonates” in Kirk-Othmer “Encyclopedia of Chemical Technology”, Second Edition, Vol. 19, pp. 291 et seq. published by John Wiley & Sons, N.Y. (1969). Other descriptions of neutral and basic sulfonate salts and techniques for making them can be found in the following U.S. Pat. Nos. 2,174,110; 2,174,506; 2,174,508; 2,193,824; 2,197,800; 2,202,781; 2,212,786; 2,213,360; 2,228,598; 2,223,676; 2,239,974; 2,263,312; 2,276,090; 2,276,097; 2,315,514; 2,319,121; 2,321,022; 2,333,568; 2,333,788; 2,335,259; 2,337,552; 2,347,568; 2,366,027; 2,374,193; 2,383,319; 3,312,618; 3,471,403; 3,488,284; 3,595,790; and 3,798,012. These and all other patents, books, excerpts, articles, and literature cited herein are fully incorporated by reference.
Although the prior art is replete with prior art concerning the use of alkylbenzene based detergents in hydrocarbon based oils such as motor oils, hydraulic fluids, cuffing fluids, etc., none have thus far provided commercially quantities of an alkylbenzene based detergent component in which the hydrocarbon tails of the molecule have carbon numbers of any integral value in the range of between about 16 and 30 carbon atoms per molecule, in which the 2-phenyl isomer content is in the range of between about 10% and 13%. We have recognized that a need exists for a method of linear alkylbenzene (“LAB”) production having high substrate olefin conversion, controlled selectivity to 2-phenyl isomer LAB, and employing a catalyst having long lifetimes and easy handling, by which controllable 2-phenyl isomer content and low dialkylate content can be achieved in materials having relatively long hydrocarbon tails attached to a benzene ring in a linear alkylbenzene based detergent.
The present invention employs hydrogen fluoride as a catalyst in the production of long-tail linear alkylbenzenes. The processing conditions used in preparing the materials of this invention may in one form of the invention provide essentially any desired percentage content of 2-phenyl isomer in the range of about 8 to about 27% (on a weight basis) in the finished product by adjusting the processing parameters. In this way, LAB may be produced having any desired 2-phenyl isomer content in the range of about 10% to 13% by weight based on the total weight of the alkylbenzene.
This invention, in one broad respect, is a process for the production of linear alkylbenzenes which comprises contacting benzene and an olefin having about 8 to about 30 carbons in the presence of an effective catalytic amount of hydrogen fluoride to form linear alkylbenzenes, wherein the isomerization of the olefins is conducted in the same process step as the alkylation of benzene
In another broad respect, this invention is a process for the production of oil-soluble alkylbenzene sulfonates suitable for use in fluids used in the transportation industry, including without limitation, additives for passenger car engine oils, additives for diesel engine oils, driveline lubricants, transmission fluids, or any other application in which an oil-soluble sulfonate salt or an overbased sulfonate confers a beneficial property to the performance of the lubricant.
For whatever reason, the alkylbenzenes within the prior art which are sold as a raw material from which overbased sulfonates may be prepared all contain benzene at a level of between about 3 and 10 parts per million. Benzene is notorious for causing leukemia. The present invention provides alkylbenzenes from which overbased alkaline earth metal sulfonates may be prepared in which benzene is present at a level of less than 100 parts per billion.
In addition, the materials of the prior art all contain significant levels of 1-phenyl (1-aryl) isomer. According to this invention, the 1-phenyl (1-aryl) content is negligible, being less than 0.3% by weight based on the total weight of all alkylaryl isomers present in a mixture of the invention.

SUMMARY OF THE INVENTION

The present invention provides a process for production of alkylaromatic compounds which comprises the steps of:

- a) co-mingling linear alpha olefins, having 16 to 40 carbon atoms per molecule, with a non-reactive diluent, such as normal or branched paraffin to form a mixture of alpha olefins and paraffins;
- b) feeding the mixture of alpha olefins and paraffins into a reaction zone along with a feed aromatic hydrocarbon and liquid hydrogen fluoride, under alkylation-promoting conditions, to produce an effluent stream containing the feed aromatic hydrocarbon, hydrogen fluoride, paraffin, and alkylaromatic hydrocarbon product;
- c) separating substantially all of the hydrocarbon mixture in the reaction zone effluent stream from the liquid phase hydrogen fluoride present in the effluent stream; and
- d) and recovering the product alkylaromatic hydrocarbon.
  The product alkylaromatic hydrocarbon is conveniently recovered by a series of steps involving passage of the hydrocarbon mixture through a plurality of stripping columns to remove the feed aromatic hydrocarbon and paraffin diluent components. The alkylaromatic product is recovered as a net bottom stream.

In another form of the invention is provided a process for producing an alkylaromatic hydrocarbon which comprises the steps of:

- a) dehydrogenating a paraffin to form an olefin;
- b) sending a feed stream of benzene and the olefin through a conduit to a linear alkylbenzenes alkylation reactor containing hydrogen fluoride under conditions which enable isomerization of the olefin to occur simultaneously with alkylation of benzene by the olefin, to form a crude linear alkylbenzenes stream;
- c) distilling the crude linear alkylbenzenes stream in a first distillation column to separate benzene that did not react and to form a benzene-free linear alkylbenzenes stream;
- d) distilling the benzene-free linear alkylbenzenes stream in a second distillation column to separate any paraffin present and to form a paraffin-free linear alkylbenzenes stream;
- e) distilling the paraffin-free linear alkylbenzene stream in a third distillation column to provide an overhead of a purified linear alkylbenzene stream and removing a bottoms stream containing heavies.

Certain terms and phrases have the following meanings as used herein.
“Conv.” and “Conversion” mean the mole percentage of a given reactant converted to product. Generally, olefin conversion is about 95 percent or more in the practice of this invention.
“Sel.” and “Selectivity” mean the mole percentage of a particular component in the product. Generally, selectivity to the 2-phenyl isomer is about 70% or more in the practice of this invention.
“LAB” means a mixture linear alkylbenzenes which comprises a benzene ring appended to any carbon atom of a substantially linear alkyl chain having any number of carbon atoms in the range of 16 to 30, inclusive. Hydrogen fluoride is useful as a catalyst useful in the production of LAB's in accordance with the process of manufacturing LAB's of this invention. LAB is useful as starting material to produce sulfonated LAB, which is useful as a surfactant.
“LAB sulfonates” means LAB which has been sulfonated to include an acidic sulfonate group appended to the benzene ring (thus forming a “parent acid”), and subsequently rendered to a form more soluble to aqueous solution than the parent acid by neutralization using any of alkali metal hydroxides, alkaline earth hydroxides, ammonium hydroxides, alkylammonium hydroxides, or any chemical agent known by those skilled in the art to react with linear alkylbenzene sulfonic acids to form water-soluble LAB sulfonates.
“Detergent range” means an olefin, alkyl group, or molecular species (including without limitation LAB, LAB sulfonates, and overbased LAB sulfonates) that comprises any number of carbon atoms selected from: 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30, as warranted by the context, including mixtures of two or more such species having different numbers of carbon atoms appended to the aromatic ring.
“Substantially linear” when referring to a hydrocarbon or alkyl chain that is part of an alkylbenzene, whether the alkylbenzene is sulfonated or not, means a hydrocarbon comprising between 16 and 30 carbon atoms linked to one another to form a straight chain, wherein the carbon atoms of said straight chain may have only hydrogen atoms or a methyl group bonded to them as appendages.
“Branched alkyl” when referring to a hydrocarbon or alkyl chain that is part of an alkylbenzene, whether the alkylbenzene is sulfonated or not, means a hydrocarbon comprising between 16 and 30 carbon atoms linked to one another to form a straight chain, wherein one or more of the carbon atoms of said straight chain may have a hydrogen atom and any alkyl group other than a methyl group (including without limitation ethyl groups), bonded to them as appendages.
“Branched alkylbenzene” means a molecular species which comprises a branched alkyl chain appended to a benzene ring.
“Branched alkylbenzene sulfonate” means a water-soluble salt of a branched alkylbenzene that has been sulfonated.
“Overbased sulfonate” means an LAB sulfonate in which an amount of any one or more alkaline metals selected from the group consisting of Na, K, Mg, Ca, Ba, Sr are present in any amount which is greater than the stoichiometric amount of metal which would be present if the parent LAB sulfonic acid, R—S(═O)(═O)OH, were fully neutralized. The exact structure of this type compound has not been determined.
“2-phenyl alkylbenzenes” means a benzene ring having at least one alkyl group attached to it, wherein the alkyl group comprises any number of carbon atoms between 16 and 30 (including every integral number therebetween) linked to one another so as to form a substantially linear chain and wherein the benzene ring is attached the alkyl group at a carbon atom that is adjacent to the terminal carbon of the substantially linear chain. Thus, the carbon atom that is attached to the benzene ring has a methyl group and an alkyl group attached to it in a 2-phenyl alkylbenzene. Thus, the 2-phenyl isomer of substantially linear LAB produced in accordance with this invention is of the formula:

in which n is any integer between about 12 and about 30; R₁, R₂, R₃, R₄, and R₅are each independently selected from the group consisting of: hydrogen, a methyl group, an ethyl group, a propyl group, and a butyl group; B is selected from the group consisting of: hydrogen, methyl, or ethyl; B is attached to any single carbon atom along the —(CH₂)_n— portion of the alkyl chain; and the total 2-aryl isomer content of said mixture of alkylbenzenes is between about 8% and about 30% by weight based on the total weight of all alkylbenzenes present in said mixture and in which the 1-aryl isomer content is less than about 3% by weight based on the weight of all isomers of alkylbenzene derivatives present.
“Alkylbenzenes” means all species containing an alkyl group, whether linear or branched, appended to a benzene ring. Within this definition are also embraced monoalkyltoluenes, monoalkylxylenes, alkylethylbenzenes, etc.
“Sulfonated 2-phenyl alkylbenzenes” means 2-phenyl alkylbenzenes as defined above which further comprise a sulfonate group attached to the benzene ring of a 2-aryl alkylbenzene, regardless of the position of the sulfonate group on the ring with respect to the location of the alkyl group. However, it is typical, though not always the case (as in ortho isomers invariably present) for the sulfonate group to appear in the position R₃above with respect to a single alkyl group attached to the benzene ring, as shown in the following structure:

in which n is any integer between about 12 and about 30; R₁, R₂, R₄, and R₅are each independently selected from the group consisting of: hydrogen, a methyl group, an ethyl group, a propyl group, and a butyl group; B is selected from the group consisting of: hydrogen, methyl, or ethyl; B is attached to any single carbon atom along the —(CH₂)_n— portion of the alkyl chain; and the total 2-aryl isomer content of said mixture of alkylbenzenes is between about 8% and about 30% by weight based on the total weight of all alkylbenzenes present in said mixture and in which the 1-aryl isomer content is less than about 3% by weight based on the weight of all isomers of alkylbenzene derivatives present.
“Motor fuel” means those compositions generally recognized by those in the art as liquid hydrocarbon fuels in the gasoline boiling range, including hydrocarbon base fuels. Within the meaning of this term is included those fuels often termed as “petroleum distillate fuels” by those in the art and which have the above characteristic boiling points. The term is, however, not intended to be restricted to straight-run distillate fractions. The distillate fuel can be straight-run distillate fuel, catalytically or thermally cracked (including hydrocracked) distillate fuel, or a mixture of straight-run distillate fuel, naphthas and the like with cracked distillate stocks. Also, the base fuels used in the formulations of the fuel compositions of the present invention can be treated in accordance with well-known commercial methods such as acid or caustic treatments, hydrogen solvent refining, clay treatment, etc. Gasolines are supplied in a number of different grades depending upon the type of service for which they are intended. The gasolines useful in the present invention include those designed as motor and aviation gasolines. Motor gasolines include those defined by ASTM specification D-439-73 and are composed of a mixture of various types of hydrocarbons including aromatics, olefins, paraffins, isoparaffins, naphthalenes, and occasionally diolefins. Motor gasolines normally have a boiling range within the limits of about 20 degrees C. to about 230 degrees C., while aviation gasolines have narrower boiling ranges, usually within the limits of about 37 degrees C. to 165 degrees C. Also within this definition are the kerosene range fuels, which include diesel fuels and jet fuel.
“Ashless Dispersants” means any material regarded by those in the motor fuel arts as possessive of dispersant characteristics and which upon combustion leaves substantially no ash.
“Base Number” or “BN” refers to the amount of base equivalent to milligrams of KOH in one gram of sample. Thus, higher BN numbers reflect more alkaline products, and therefore a greater alkalinity reserve. The BN of a sample can be determined by ASTM Test No. D2896 or any other equivalent procedure.
In this specification and the appended claims, unless otherwise specified, all percentages are in weight percent, all ratios are molar ratios, and all molecular weights are number average molecular weights.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a representation of a first continuous reactive distillation column employed in the practice of this invention.
FIG. 2 shows a representation of a second continuous reactive distillation column employed in the practice of this invention.
FIG. 3 shows a representative process scheme for one embodiment of this invention where a fluorine-containing mordenite is employed with a second, solid catalyst to achieve variable 2-phenyl isomer content depending on the relative proportions of the two catalysts.

DETAILED DESCRIPTION

Reactants for LAB Production

In the practice of this invention, benzene or a substituted benzene such as toluene, ethylbenzene, propylbenzene, butylbenzene, or one or more xylenes is alkylated with an olefinic material to form LAB. Olefins and benzene can be handled and purified using standard techniques recognized by those of ordinary skill in the art. In this regard, it is preferred that the reactants are substantially free from hydric compounds such as water and alcohols, etc. The olefins employed in the practice of this invention have from about 16 to about 30 carbons per molecule, and in one form of the invention preferably from about 20 to about 24 carbon atoms. It is most preferred that the olefinic material be a mono-olefin. It is most preferred that the mono-olefin be an alpha-olefin, in which the double bond is located in a terminal ethylenic unit; however, internal olefins are suitable as well, since they are isomerized in the same step as the alkylation, in one preferred form of the invention.
Commonly, such olefins would be available from a paraffinic media of the same carbon range. One route by which olefins in the 16 to 30 carbon number range are available is from dehydrogenating a mixture of paraffins in the same carbon number range, namely C₋₁₆to C₋₃₀paraffins. Such dehydrogenation may be carried out even if such a paraffin mixture has any appreciable olefin content, for example, an olefin content in the range of about 5 to 20%. It is especially preferred to carry out such a process using our catalyst and processes as described in U.S. Pat. Nos. 6,417,135 and 6,700,028, both of which are fully incorporated herein by reference thereto.

Process Conditions, Procedures, and Apparatus

The process of this invention can be carried out using the continuous reactive distillation column depicted in FIG. 1. In FIG. 1, a feed mixture of benzene and olefin, generally at a benzene-to-olefin molar ratio range of about 1:1 to 100:1 flows from feed pump 10 to feed inlet 14 via line 12. The feed mixture falls to a region containing hydrogen fluoride gas 32 where alkylation and isomerization occurs. Alternatively, while not depicted in FIG. 1, the benzene and olefin can be introduced separately into the zone with mixing occurring in the HF zone, or the reactants can be mixed via an in-line mixer prior to introducing the reactants into the catalyst zone, or the reactants can be injected separately above the HF zone with mixing affected by use of standard packing above the zone, or the reactants can be sparged into the chamber above the zone. In the catalyst zone 32, the falling feed mixture also contacts rising vapors of unreacted benzene which has been heated to reflux in reboiler 42 by heater 40. Such rising vapors pass over thermocouple 38 which monitors temperature to provide feedback to heater 40. The rising vapors of benzene and/or olefin also pass through standard packing 36 (e.g., 7.5 inches of goodloe packing). The rising vapors heat thermocouple 30 which connects to bottoms temperature controller 28 which activates heater 40 when temperature drops below a set level.
Prior to startup, the system may be flushed with nitrogen which enters via line 54 and which flows through line 58. After startup, a nitrogen blanket is maintained over the system. Also prior to startup and during nitrogen flush, it may be desirable to heat catalyst zone 32 so as to drive off water. In an alternate form of the invention, HF gas may be admitted to line 54.
Residual water from the feed mixture or which otherwise enters the system is collected in water trap 24 upon being liquefied at condenser 21 (along with benzene vapor). If the feed is very dry (free of water) the water trap 24 may not be needed. Removing water leads to better product quality. Hence, the water trap 24 is optional. The same applies to FIG. 2. Condenser 21 is cooled via coolant such as water entering condenser 21 via port 22 and exiting via port 20. As needed, water in water trap 24 may be drained by opening drain valve 26.
As needed, when LAB content in reboiler 42 rises to a desired level, the bottoms LAB product may be removed from the system via line 47, using either gravity or bottoms pump 48 to withdraw the product. When product is so withdrawn, valve 44 is opened.
In FIG. 1, dip tube 46, which is optional, is employed to slightly increase the pressure in reboiler 42 to thereby raise the boiling point of benzene a degree or two. Likewise, a pressure generator 56 may be optionally employed to raise the pressure of the system. Other standard pressure increasing devices can be employed. Pressure can thus be increased in the system such that the boiling point of benzene increases up to about 200° C.
In FIG. 1, control mechanisms for heat shutoff 50 and pump shutoff 52 are depicted which serve to shut off heat and pump if the liquids level in the system rises to such levels. These control mechanisms are optional and may be included so that the catalyst zone does not come into contact with the bottoms of the reboiler.
In the practice of this invention in the alkylation of benzene, a wide variety of process conditions can be employed. In this regard, the temperature in the catalyst zone may vary depending on reactants, rate of introduction into the catalyst zone, size of the catalyst zone, and so forth. Generally, the zone is maintained at the reflux temperature of benzene depending on pressure. Typically, the temperature of the catalyst zone is above about 70° C., and most likely about 78° C. or more in order to have reasonable reaction rates, and about 200° C. or less to avoid degradation of reactants and products and to avoid coke build-up in the catalyst zone. Preferably, the temperature is in the range from about 80° C. to about 140° C. The process may be operated at a variety of pressures during the contact of HF with the reactants, with pressures of about atmospheric most typically being employed. When the process is operated using a system as depicted in FIGS. 1 and 2, the reboiler temperature is maintained such that benzene and olefin vaporize, the temperature varying depending on olefin, and generally being from about 80° C. to about 250° C. for olefins having 16 to 24 carbons. The composition of the reboiler will vary over time, but is generally set initially to have a benzene olefin ratio of about 10:1, with this ratio being maintained during the practice of this invention. The rate of introduction of feed into the catalyst zone may vary, and is generally at a liquid hourly space velocity (“LHSV”) of about 0.05 hr⁻¹to about 10 hr⁻¹, more typically from about 0.05 hr⁻¹to about 1 hr⁻¹. The mole ratio of benzene to olefin introduced into the catalyst zone is generally from about 1:1 to about 100:1. In commercial benzene alkylation operations, it is common to run at mole ratios of from about 2:1 to about 20:1, which can suitably be employed in the practice of this invention, and to charge said olefins as an olefin-paraffin mixture comprising 5% to 20% olefin content. Said olefin-paraffin mixtures are normally generated commercially through dehydrogenation of the corresponding paraffin starting material over a noble metal catalyst as previously specified.
Another continuous reactive distillation apparatus is depicted in FIG. 2. In FIG. 2, the feed mixture enters the reactor via feed inlet 114. The feed mixture falls through the column into catalyst zone 132, wherein alkylation to form LAB occurs. A thermowell 133 monitors the temperature of said catalyst zone 132. The catalyst zone 132 may be optionally heated externally and is contained within 1¼ inch stainless steel tubing. Goodloe packing is positioned at packing 136 and 137. LAB product, as well as unreacted benzene and olefin, fall through packing 136 into reboiler 142. In reboiler 142, electric heater 140 heats the contents of reboiler 142 such that heated vapors of benzene and olefin rise from the reboiler 142 to at least reach catalyst zone 132. As needed, the bottoms LAB product may be removed from reboiler 142 by opening bottoms valve 144 after passing through line 147 and filter 145. Residual water from the feed mixture, or which otherwise enters the system, may be condensed at condenser 121 which is cooled with coolant via inlet line 122 and exit line 120. The condensed water falls to water trap 124, which can be drained as needed by opening drain valve 126. Temperature in the system is monitored via thermocouples 138, 130, and 165. The system includes pressure release valve 166. A nitrogen blanket over the system is maintained by introduction of nitrogen gas via inlet line 154. Level control activator 150 activates bottoms level control valve 151 to open when the liquids level in the reboiler rises to the level control activator 150.
While the systems depicted in FIG. 1 and FIG. 2 show single catalyst zone systems, it must be appreciated that multi-catalyst zone reactors are within the scope of this invention, as well as multiple ports for inlet feeds, water traps, product removal lines, and so forth. Moreover, the process may be run in batch mode, or in other continuous processes using plugflow designs, trickle zone designs, and fluidized zone designs.
As average molecular weight of olefins increases, particularly when the average number of carbons is greater than about 15, the selectivity to the 2-isomer is less than for lower molecular weight olefins. It is thus preferred, although not absolutely necessary, that the product of the alkylation using HF is sent to a second, finishing catalyst zone to improve yield. An example of such a second catalyst is HF-treated clay such as montmorillonite clay treated in accordance with the invention to have about 0.5% fluoride and calcined as stated in Huntsman's earlier U.S. Pat. No. 6,630,430 which is fully incorporated herein by reference.
The scheme of FIG. 3 is shown in the context of LAB alkylation based on a feed from a paraffin dehydrogenation facility. Thus, in FIG. 3 fresh paraffin is fed to a conventional dehydrogenation apparatus 210 via line 211, with recycled paraffin being introduced from the paraffin column 250 via line 252. Dehydrogenated paraffin from the dehydrogenation apparatus 210 is then pumped into an alkylation reactor (or reactors) 230 that contains hydrogen fluoride. The dehydrogenated paraffin feed may of course be supplied from any provider. The source of dehydrogenated paraffin (olefin) is not critical to the practice of this invention. LAB product from alkylation unit 230 may thereafter be purified by a series of distillation towers.
In this regard, alkylation effluent may be delivered to a benzene column 240 by way of line 231. It should be appreciated that the alkylation product may be sent offsite for purification. Further, the particular purification scheme used is not critical to the practice of this invention. The scheme depicted in FIG. 3 is instead representative of a typical commercial operation. In FIG. 3, unreacted benzene is distilled off from the crude LAB product. Benzene is then recycled to the alkylation reactor 230. The benzene-free LAB crude product from the benzene column 240 is pumped through line 241 to paraffin column 250 where any paraffin present is distilled off, with the distilled paraffin being recycled to paraffin dehydrogenation unit 210 via line 252. Paraffin-free crude LAB from the paraffin column 250 is transported to a refining column 260 where purified LAB is distilled and removed via line 262. Heavies (e.g., dialkylates and olefin derivatives) are withdrawn from refining column 260 via conduit 261.
It should be appreciated that columns 240, 250, and 260 may be maintained at conditions (e.g., pressure and temperature) well known to those of skill in the art and may be packed with conventional materials, if desired.
Hydrocarbon and other base oils such as the vegetable oils are known to be rarely used in their pure forms in any application, but rather contain various chemical additives designed to increase the performance of such oils, or to extend the useful lives of either the oils themselves or the equipment in which they are designed to function. In this regard, the prior art teaches the use of various oil additives which include without limitation: detergents, dispersants, anti-wear agents, extreme pressure additives, antioxidants, corrosion inhibitors, viscosity modifiers, pour point depressants, antifoam agents, friction modifiers, metal deactivators, water scavengers, free radical scavengers, and compatibilizers.
Although the present invention has been described largely in reference to the alkylation of benzene using olefins as an alkylating agent, it should be appreciated that substituted benzenes are also useful as starting materials within the context of the present invention, provided that the chemical groups appended to the benzene ring are not prohibitively de-activating of the benzene ring structure. In this regard, toluene is a functionally equivalent starting material which may be used in place of all or part of the benzene employed. Other substituted benzenes such as xylenes are also useful in this regard, as well as ethylbenzene, propylbenzene, and butylbenzene.
In cases where a substituted benzene is alkylated in accordance with the principles of this invention, the reaction product consists predominantly of para-substituted reaction products, with some ortho substitution. Subsequent sulfonation of such a mixture to provide sulfonate derivatives results in a mixture of sulfonates or their salts or esters as well. These materials may be conveniently described by the formula:

in which n is any integer between about 12 and about 30; R₁, R₂, R₃, R₄, and R₅are each independently selected from the group consisting of: hydrogen, a methyl group, an ethyl group, a propyl group, a butyl group, a sulfonic acid group, an sulfonate group, and salts and esters thereof; B is selected from the group consisting of: hydrogen, methyl, or ethyl; B is attached to any single carbon atom along the —(CH₂)_n— portion of the alkyl chain; and the total 2-aryl isomer content of said mixture of alkylbenzenes is between about 8% and about 30% by weight based on the total weight of all alkylbenzenes present in said mixture and in which the 1-aryl isomer content is less than about 3% by weight based on the weight of all isomers of alkylbenzene derivatives present.

Detergents Useful in Hydrocarbon Oils

One popular class of detergents used in lubricating oils, cutting fluids, and the like are the oil soluble sulfonates. Within this broad class are the aromatic sulfonates of the type described in this specification, particularly the LAB sulfonates. These materials are preferred because of their effectiveness and compatibility with other components found in finished oil products, their widespread availability, and relatively low cost. Additionally, many of these detergent materials are anionic in nature, which means that any one of a wide range of selected cationic species may accompany the anionic detergent, which is of particular benefit when it is desired to incorporate other metals into the composition. The most commonly used salts of these acids in hydrocarbon oils are the sodium, potassium, lithium, calcium, magnesium, strontium and barium salts. The “basic salts” are those metal salts known to the art wherein the metal is present in a stoichiometrically larger amount than that necessary to neutralize the acid. The calcium- and barium-overbased petrosulfonic acids are typical examples of such basic salts.
The terms “overbased,” “superbased,” and “hyperbased,” are terms of art which are generic to well known classes of the metallic sulfonates and other materials. These overbased materials have also been referred to as “complexes,” “metal complexes,” “high-metal containing salts,” and the like. Overbased materials are characterized by a metal content in excess of that which would be present according to the stoichiometry of the metal and the particular organic compound reacted with the metal, e.g., a sulfonic acid. Thus, if a monosulfonic acid such as an LAB sulfonate is neutralized with a basic metal compound, e.g., calcium hydroxide, the “normal” metal salt produced will contain one equivalent of calcium for each equivalent of acid. However, as is well known in the art, various processes are available which result in an inert organic liquid solution of a product containing more than the stoichiometric amount of metal. The solutions of these products are referred to herein as overbased materials. Following these procedures, the sulfonic acid or an alkali or alkaline earth metal salt thereof can be reacted with a metal base and the product will contain an amount of metal in excess of that necessary to neutralize the acid, for example, 4.5 times as much metal as present in the normal salt or a metal excess of 3.5 equivalents. The actual stoichiometric excess of metal can vary considerably, for example, from about 0.1 equivalent to about 30 or more equivalents depending on the reactions, the process conditions, and the like. These overbased materials useful in preparing the disperse systems will contain from about 3.5 to about 30 or more equivalents of metal for each equivalent of material which is overbased. In the present specification and claims the term “overbased” is used to designate materials containing a stoichiometric excess of metal and is, therefore, inclusive of those materials which have been referred to in the art as overbased, superbased, hyperbased, etc., as discussed supra.
The present invention thus provides LAB from which LAB sulfonates may be prepared via conventional sulfonation techniques, and from which may further be prepared overbased sulfonates, using techniques known to those skilled in the art.
The overbased materials are prepared by treating a reaction mixture comprising the organic material to be overbased, a reaction medium consisting essentially of at least one inert, organic solvent for said organic material, a stoichiometric excess of a metal base, and a promoter with an acidic material. The methods for preparing the overbased materials as well as an extremely diverse group of overbased materials are well known in the prior art and are disclosed for example in the following U.S. Pat. Nos. 2,616,904; 2,616,905; 2,616,906; 2,616,911; 2,616,924; 2,616,925; 2,617,049; 2,695,910, 2,723,234; 2,723,235; 2,723,236; 2,760,970; 2,767,164; 2,767,209; 2,777,874; 2,798,852; 2,839,470; 2,856,359; 2,859,360; 2,856,361; 2,861,951; 2,883,340; 2,915,517; 2,959,551; 2,968,642; 2,971,014; 2,989,463; 3,001,981; 3,027,325; 3,070,581; 3,108,960; 3,147,232; 3,133,019; 3,146,201; 3,152,991; 3,155,616; 3,170,880; 3,170,881; 3,172,855; 3,194,823; 3,223,630; 3,232,883; 3,242,079; 3,242,080; 3,250,710; 3,256,186; 3,274,135; 3,492,231; 4,230,586. 6,488,725; 6,197,075; 5,944,858; 5,919,276; 4,690,687; 4,505,718; 4,372,862; 4,260,500; 4,253,976; 4,252,659; 4,225,446; 4,179,385; 4,164,474; 4,129,508; 4,104,180; 6,015,778; and 4,094,801. The foregoing patents disclose processes, materials which can be overbased, suitable metal bases, promoters, and acidic materials, as well as a variety of specific overbased products useful in producing the disperse systems of this invention and are, accordingly, incorporated herein by reference.
U.S. Pat. No. 4,086,170 (De Clippeleir et al., Apr. 25, 1978) relates to calcium sulfonates and concentrated oily solutions thereof that are prepared by reacting a solution of alkylbenzene sulfonic acids with an excess of a calcium oxide having a medium or low activity towards water and with carbon dioxide. Oily solutions of overbased calcium sulfonate obtained from such a calcium oxide are limpid and filterable. U.S. Pat. No. 4,604,219 (Whittle, Aug. 5, 1986) is directed to alkaline earth calcium sulfonates that are derived from natural or synthetic feedstocks or a mixture of both which can be overbased by introducing into a mixture comprising a neutral alkaline earth calcium sulfonate, a lower alcohol, a light hydrocarbon diluent carbon dioxide and water. The water is introduced continuously and at a uniform rate over 1-4 hours, preferably 1-3 hours into the heated mixture with carbon dioxide. Water is added in a molar ratio water/calcium oxide of 0.1 to 1.2 preferably 0.4 to 0.8. It has been found that both the water rate and amount are critical. It has been unexpectedly found that a superior product is formed by adding water continuously during carbonation rather than all charged in one or several increments at the beginning of the carbonation. In this reference, a high calcium sulfonate product with improved filterability and high clarity is formed with good lime utilization. U.S. Pat. No. 4,775,490 (Nichols et al., Oct. 4, 1988) describes a process for overbasing a substrate comprising mixing the substrate, water, a phenol, a source of magnesium and a carbonating agent, wherein the water is retained throughout the overbasing reaction and provided further that the weight ratio of the water to the magnesium is in a 10:1 to 1:5 weight ratio, thereby obtaining a magnesium overbased substrate. U.S. Pat. No. 4,954,272 (Jao, et al., Sep. 4, 1990) is directed to a process for producing an overbased oil soluble calcium sulfonate having a TBN of 325, said process comprising: (a) diluting a neutral calcium sulfonate with a hydrocarbon solvent and a lower alkanol; (b) adding to the diluted calcium sulfonate solution, CaO, Ca(OH).sub.2 and H₂O in molar ratios of CaO:Ca(OH)₂of about 90:10 to about 20:80 and of H₂O:CaO of about 0.15:1 to about 0.30:1; (c) heating the sulfonate mixture to a temperature ranging from about 100.degree. F. to about 170.degree. F. under a pressure ranging from about 0 to about 50 p.s.i.g.; (d) passing CO₂into the heated sulfonate mixture for a period of about 50 to out 200 minutes; (c) adding a diluent oil to the CO₂treated sulfonate mixture; (f) separating the solids from the liquid of the sulfonate mixture; and (g) stripping the hydrocarbon solvent from the resulting overbased oil soluble sulfonate product having TBN of 325. U.S. Pat. No. 5,259,966 (Burke, Jr., et al., Nov. 9, 1993) provides a process for preparing an overbased calcium salt, comprising mixing together: (a) an oil-soluble acid material; (b) a promoter comprising: (i) an alcohol or alcohol mixture, and (ii) an inorganic calcium salt other than chloride which is soluble in the alcohol mixture of (i), or an acid or salt which forms said inorganic calcium salt when treated with a calcium base; and (c) greater than 1 equivalent of a calcium base per equivalent of oil-soluble acid material. U.S. Pat. No. 5,534,168 (Cleverley et al., Jul. 9, 1996) relates to the use of magnesium oxide of specified, low, reactivity in a process for the production of overbased magnesium sulfonates, together with the introduction of water and an alcohol, into the reaction mixture during carbonation, makes it possible to prepare high base number products which have very low post carbonation sediments and which can be purified by rapid filtration.
Other detergents known to those skilled in the art are useful as a component of a composition according to the invention in addition to the LAB based detergents described herein.

Dispersants Useful in Hydrocarbon Oils

Although a dispersant used in a hydrocarbon oil may be a multifunctional material that can confer other beneficial properties to a base oil, dispersants are primarily used in hydrocarbon oils for their ability to maintain small particles of dirt, combustion products, metal fines, etc. in the liquid phase, to prevent deposition and accumulation of sludges in places where eddy currents exist in various equipment and wares.
The use of acylated nitrogen compounds as dispersants in lubricants is disclosed in numerous patents, including U.S. Pat. Nos. 3,172,892; 3,219,666; 3,272,746; 3,310,492; 3,341,542; 3,444,170; 3,455,831; 3,455,832; 3,576,743; 3,630,904; 3,632,511; 3,804,763; and 4,234,435.
The book “Lubricant Additives” by M. W. Ranney, published by Noyes Data Corporation of Parkridge, N.J. (1973), discloses a number of overbased metal salts of various sulfonic acids which are useful as detergent/dispersant in lubricants. The book also entitled “lubricant Additives” by C. V. Smallheer and R. K. Smith, published by the Lezius-Hiles Co. of Cleveland, Ohio (1967), similarly discloses a number of overbased sulfonates which are useful as dispersants. U.S. Pat. No. 4,100,082 discloses the use of neutral or overbased metal salts of organic sulfur acids as detergent/dispersants for use in fuels and lubricants.
Ashless detergents and dispersants are so called despite the fact that, depending on its constitution, the dispersant may upon combustion yield a non-volatile material such as boric oxide or phosphorus pentoxide; however, it does not ordinarily contain metal and therefore does not yield a metal-containing ash on combustion. Many types are known in the art, and any of them are suitable for use in the lubricant compositions and functional fluids of this invention. The following are illustrative of dispersants, not delimitive of the term, and are incorporated by reference herein:

- (1) Reaction products of carboxylic acids (or derivatives thereof) containing at least about 34 and preferably at least about 54 carbon atoms with nitrogen containing compounds such as amine, organic hydroxy compounds such as phenols and alcohols, and/or basic inorganic materials. Examples of these “carboxylic dispersants” are described in many U.S. Pat. Nos., including 3,219,666; 4,234,435; and 4,938,881. These include the products formed by the reaction of a polyisobutenyl succinic anhydride with an amine such as a polyethylene amine.
- (2) Reaction products of relatively high molecular weight aliphatic or alicyclic halides with amines, preferably oxyalkylene polyamines. These may be characterized as “amine dispersants” and examples thereof are described for example, in the following U.S. Pat. Nos. 3,275,554; 3,438,757; 3,454,555; and 3,565,804.
- (3) Reaction products of alkyl phenols in which the alkyl group contains at least about 30 carbon atoms with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines), which may be characterized as “Mannich dispersants.” The materials described in the following U.S. Pat. Nos. are illustrative: 3,649,229; 3,697,574; 3,725,277; 3,725,480; 3,726,882; and 3,980,569.
- (4) Products obtained by post-treating the amine or Mannich dispersants with such reagents as urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted succinic anhydrides, nitriles, epoxides, boron compounds, phosphorus compounds or the like. Exemplary materials of this kind are described in the following U.S. Pat. Nos. 3,639,242; 3,649,229; 3,649,659; 3,658,836; 3,697,574; 3,702,757; 3,703,536; 3,704,308; and 3,708,422.
- (5) Interpolymers of oil-solubilizing monomers such as decyl methacrylate, vinyl decyl ether and high molecular weight olefins with monomers containing polar substituents, e.g., aminoalkyl acrylates or acrylamides and poly-(oxyethylene)-substituted acrylates. These may be characterized as “polymeric dispersants” and examples thereof are disclosed in the following U.S. Pat. Nos. 3,329,658; 3,449,250; 3,519,565; 3,666,730; 3,687,849; and 3,702,300.

Antiwear Agents

A composition according to this invention may also include a sulfur-, phosphorus-, or sulfur- and phosphorus-containing antiwear agent. The term antiwear agent is used to refer to compounds which provide wear protection properties to lubricating compositions and functional fluids. Antiwear agents are useful in controlling wear and may sometimes also act as extreme pressure agents and as antioxidants. These antiwear agents include sulfurized organic compounds, hydrocarbyl phosphates, phosphorus-containing amides, phosphorus-containing carboxylic esters, phosphorus-containing ethers, and dithiocarbamate-containing compounds. Examples of hydrocarbyl phosphates include hydrocarbyl thiophosphates. Thiophosphates may contain from one to about three sulfur atoms, preferably one or two sulfur atoms. Thiophosphates are prepared by reacting one or more phosphites with a sulfurizing agent including sulfur, sulfur halides, and sulfur containing compounds. Salts of thiophosphates include zinc dithiophosphates. Other antiwear agents known to those skilled in the art are useful as a component of a composition according to the invention. Other dispersants known to those skilled in the art are useful as a component of a composition according to the invention.

Anti-Oxidants

A particularly valuable class of additives known as antioxidants are widely used in lubricating oil formulations, cutting oils, and functional fluids. Antioxidants are materials which inhibit oxidative decomposition of the oil under consideration. Although several examples are given below, these examples should be considered exemplary only of the wide variety of antioxidants which may be usefully combined with the detergent components of this invention.
In U.S. Pat. No. 2,282,710 to Dietrich issued May 12, 1942 it is known that stabilization of petroleum hydrocarbons against the deleterious catalytic action of metals may be obtained by compositions containing both a nitrogen and a sulfur functional group. Various cyclic, aromatic and linear carbon configurations are shown in the sulfur and nitrogen containing molecules of Dietrich. Dietrich discloses preparing his compositions by the use of ethyleneimine. Dietrich further states that his compounds are particularly effective in retarding the formation of products corrosive to metals, and particularly cadmium, silver, copper, lead and like bearing alloys under normal service conditions.
German OLS 1,066,019 published Sep. 24, 1959 by Holtschmitt et al describes various condensation products of thioglycol and nitrogen containing materials. Holtschmitt shows his compounds as containing free hydroxyl groups. Holtschmitt further discloses the use of aromatic amines containing a short aliphatic group on the aromatic ring, e.g. toluidine.
It is known from an article entitled: “Thioglycol Polymers I Hydrochloric Acid-Catalysed Auto Condensation of Thiodiglycol” by Woodward, Journal of Polymer Science the OL XLI, Pages 219-223 (1959), that the properties of a sulfur and oxygen containing compound allow end-to-end condensation. It is further known from the Woodward article that multiple sulfur linkages within the molecule, e.g. disulfides, trisulfides, and the like may be obtained.
It is further known that various amines may be utilized in antioxidant compositions. Phenothiazine compounds are known in lubricant products from U.S. Pat. No. 2,781,318 issued Feb. 12, 1957 to Cyphers. The alkyl phenothiazines of Cyphers are alkylated on the phenylene rings of the phenothiazine structure. Cyphers does not show or suggest the alkylation of the amine nitrogen in phenothiazine. The Cyphers patent is directed to the utility of phenothiazine as an antioxidant and corrosion inhibiting additive for ester, polyester, polyether and other synthetic lubricants.
U.S. Pat. No. 3,536,706 issued Oct. 27, 1970 to Randell suggests that phenothiazines may be used as additives for synthetic lubricants. The phenothiazines particularly described by Randell are those containing tertiary alkyl substituents having from 4 to 12 carbon atoms on the aryl groups which make up the phenothiazine structure. Randell also discloses fused rings on the two phenylene groups which make up the phenothiazine structure. Stated otherwise, Randell allows the utilization of naphthalene for at least one of the two aryl groups in the phenothiazine structure. U.S. Pat. No. 3,803,140 issued to Cook et al on Apr. 9, 1974 describes various tertiary alkyl derivatives of phenothiazine. N-alkyl substitution or N-alkenyl substitution is described on the phenothiazine structure. Ring alkylation when the phenothiazine is in the free nitrogen form is also shown. Cook et al express a preference for non-N substituted phenothiazine derivatives.
Cook et al also suggest that organic materials which are susceptible to oxidative degradation may benefit through the use of the compounds of their invention. Such uses include antioxidants for aliphatic hydrocarbons such as gasoline, lubricating oils, lubricating greases, mineral oils, waxes, natural and synthetic polymers such as rubber, vinyl, vinylidene, ethers, esters, amides and urethanes. The compounds of Cook et al are also suggested for stabilizing aldehydes and unsaturated fatty acids or esters thereof. Still further utilities suggested by Cook et al include the stabilization of organo-metalloid substances such as silicone polymers. Another class of uses of the compounds of Cook et al include the stabilization of vitamins, essential oils, ketones and ethers.
Normant in U.S. Pat. No. 3,560,531 issued Feb. 2, 1971, describes metallation of materials having active hydrogens including phenothiazine. U.S. Pat. No. 3,344,068 issued Sep. 26, 1967, to Waight et al describes antioxidants for ester-based lubricants. Waight et al's compounds have an N-hydrocarbyl substituted phenothiazine structure. The N-substituted phenothiazine compounds of Waight et al are also substituted in at least one position on the fused aromatic nuclei. A second required component in the compositions of Waight et al is a secondary aromatic amine having two aromatic groups attached to the nitrogen atom.
The preparation of alkylthioalkanols which are useful as intermediates for preparing the compounds of the present invention are described in U.S. Pat. No. 4,031,023 to Musser et al.
U.S. Pat. No. 2,194,527 to Winthrop et al which issued Nov. 24, 1959, describes pharmaceutical compounds such as omega-(10-phenothiazinyl)alkyl di-alkyl sulfonium salts which are useful as spasmolytics and in particular antihistaminics. U.S. Pat. No. 3,376,224 issued Apr. 2, 1968 to Elliott et al describes phenothiazine derivatives which are stated to be N-substituted methylene compounds which contain an ether linkage between the methylene group and an alkyl or cycloalkyl radical. According to Elliott et al, the alkyl or cycloalkyl radical may carry an alkoxy or other non-reactive substituent.
U.S. Pat. No. 4,915,858 describes a composition of matter which is the amine terminated reaction product obtained from two equivalents of a secondary aromatic monoamine with at least two equivalents of a betathiodialkanol. Other antioxidants known to those skilled in the art are useful as a component of a composition according to the invention.

Corrosion Inhibitors

Corrosion-inhibiting agents are exemplified by chlorinated aliphatic hydrocarbons such as chlorinated wax; organic sulfides and polysulfides such as benzyl disulfide, bis(chlorobenzyl) disulfide, dibutyl tetrasulfide, sulfurized methyl ester of oleic acid, sulfurized alkylphenol, sulfurized dipentene, and sulfurized terpene; phosphosulfurized hydrocarbons such as the reaction product of a phosphorus sulfide with turpentine or methyl oleate; phosphorus esters including principally dihydrocarbon and trihydrocarbon phosphites such as dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentyl phenyl phosphite, dipentyl phenyl phosphite, tridecyl phosphite, distearyl phosphite, dimethyl naphthyl phosphite, oleyl 4-pentylphenyl phosphite, polypropylene (molecular weight 500)-substituted phenyl phosphite, diisobutyl-substituted phenyl phosphite; metal thiocarbamates, such as zinc dioctyldithiocarbamate, and barium heptylphenyl dithiocarbamate; Group II metal phosphorodithioates such as zinc dioctylphosphorodithioate, zinc dicyclohexylphosphorodithioate, barium di(heptylphenyl)phosphorodithioate, cadmium dinonylphosphorodithioate, and the zinc salt of a phosphorodithioic acid produced by the reaction of phosphorus pentasulfide with an equimolar mixture of isopropyl alcohol and n-hexyl alcohol. Other corrosion inhibitors known to those skilled in the art are useful as a component of a composition according to the invention.

Viscosity Modifiers

Viscosity modifiers generally are polymeric materials characterized as being hydrocarbon-based polymers generally having number average molecular weights between about 25,000 and 500,000 more often between about 50,000 and 200,000. Such materials are typically added to a hydrocarbon based oil and the oil is heated, with agitation, until the polymeric material is dissolved.
Polyisobutylene has been used as a viscosity modifier in lubricating oils. Polymethacrylates (PMA) are prepared from mixtures of methacrylate monomers having different alkyl groups. Most PMA's are viscosity-modifiers as well as pour point depressants. The alkyl groups may be either straight chain or branched chain groups containing from 1 to about 18 carbon atoms.
Ethylene-propylene copolymers, generally referred to as OCP can be prepared by copolymerizing ethylene and propylene, generally in a solvent, using known catalysts such as a Ziegler-Natta initiator. The ratio of ethylene to propylene in the polymer influences the oil-solubility, oil-thickening ability, low temperature viscosity, pour point depressant capability and engine performance of the product. The common range of ethylene content is 45-60% by weight and typically is from 50% to about 55% by weight. Some commercial OCP's are terpolymers of ethylene, propylene and a small amount of nonconjugated diene such as 1,4-hexadiene. In the rubber industry, such terpolymers are referred to as EPDM (ethylene propylene diene monomer). The use of OCP's as viscosity modifiers in lubricating oils has increased rapidly since about 1970, and the OCP's are currently one of the most widely used viscosity modifiers for motor oils.
Esters obtained by copolymerizing styrene and maleic anhydride in the presence of a free radical initiator and thereafter esterifying the copolymer with a mixture of C_4-18alcohols also are useful as viscosity modifying additives in motor oils. The styrene esters generally are considered to be multifunctional premium viscosity modifiers. The styrene esters in addition to their viscosity modifying properties also are pour point depressants and exhibit dispersancy properties when the esterification is terminated before its completion leaving some unreacted anhydride or carboxylic acid groups. These acid groups can then be converted to imides by reaction with a primary amine.
Hydrogenated styrene-conjugated diene copolymers are another class of commercially available viscosity modifiers for motor oils. Examples of styrenes include styrene, alpha-methyl styrene, ortho-methyl styrene, meta-methyl styrene, para-methyl styrene, para-tertiary butyl styrene, etc. Preferably the conjugated diene contains from four to six carbon atoms. Examples of conjugated dienes include piperylene, 2,3-dimethyl-1,3-butadiene, chloroprene, isoprene and 1,3-butadiene, with isoprene and butadiene being particularly preferred. Mixtures of such conjugated dienes are useful.
The styrene content of these copolymers is in the range of about 20% to about 70% by weight, preferably about 40% to about 60% by weight. The aliphatic conjugated diene content of these copolymers is in the range of about 30% to about 80% by weight, preferably about 40% to about 60% by weight.
These copolymers typically have number average molecular weights in the range of about 30,000 to about 500,000, preferably about 50,000 to about 200,000. The weight average molecular weight for these copolymers is generally in the range of about 50,000 to about 500,000, preferably about 50,000 to about 300,000.
The above described hydrogenated copolymers have been described in the prior art such as in U.S. Pat. Nos. 3,551,336; 3,598,738; 3,554,911; 3,607,749; 3,687,849; and 4,181,618 which are hereby incorporated by reference for their disclosures of polymers and copolymers useful as viscosity modifiers in oil compositions according to this invention. For example, U.S. Pat. No. 3,554,911 describes a hydrogenated random butadiene-styrene copolymer, its preparation and hydrogenation. The disclosure of this patent is incorporated herein by reference. Hydrogenated styrene-butadiene copolymers useful as viscosity modifiers in the lubricating oil compositions of the present invention are available commercially from, for example, BASF under the general trade designation “Glissoviscal”. A particular example is a hydrogenated styrene-butadiene copolymer available under the designation Glissoviscal 5260 which has a molecular weight, determined by gel permeation chromatography, of about 120,000. Hydrogenated styrene-isoprene copolymers useful as viscosity modifiers are available from, for example, The Shell Chemical Company under the general trade designation “Shellvis”. Shellvis 40 from Shell Chemical Company is identified as a diblock copolymer of styrene and isoprene having a number average molecular weight of about 155,000, a styrene content of about 19 mole percent and an isoprene content of about 81 mole percent. Shellvis 50 is available from Shell Chemical Company and is identified as a diblock copolymer of styrene and isoprene having a number average molecular weight of about 100,000, a styrene content of about 28 mole percent and an isoprene content of about 72 mole percent. Other viscosity modifiers known to those skilled in the art are useful as a component of a composition according to the invention.

Pour Point Depressants

Pour point depressants may also be included in a formulation according to the invention. They are a particularly useful type of additive often included in the lubricating oils and functional fluids such as cutting oils or other lubricants, and often comprise oil-soluble polymers. Examples of pour point depressants include those on page 8 of Lubricant Additives” by C. V. Smalheer and R. Kennedy Smith (Lesius-Hiles Company Publishers, Cleveland, Ohio, 1967, which book is incorporated in its entirety herein by reference thereto). Other pour point depressants known to those skilled in the art are useful as a component of a composition according to the invention.

Antifoam Agents

Anti-foam agents may be used to reduce or prevent the formation of stable foam and include silicones or organic polymers. Examples of these and additional anti-foam compositions are described in “Foam Control Agents”, by Henry T. Kerner (Noyes Data Corporation, 1976), pages 125-162, which book is incorporated in its entirety herein by reference thereto. Other antifoam agents known to those skilled in the art are useful as a component of a composition according to the invention.

Friction Modifiers

The oil compositions of the present invention also may contain at least one friction modifier to provide the lubricating oil with the proper frictional characteristics for a given application. Various amines, particularly tertiary amines are effective friction modifiers. Examples of tertiary amine friction modifiers include N-fatty alkyl-N,N-diethanol amines, N-fatty alkyl-N,N-diethoxy ethanol amines, etc. Such tertiary amines can be prepared by reacting a fatty alkyl amine with an appropriate number of moles of ethylene oxide. Tertiary amines derived from naturally occurring substances such as coconut oil and oleoamine are available from Armour Chemical Company under the trade designation “Ethomeen”. Particular examples are the Ethomeen-C and the Ethomeen-O series. Sulfur-containing compounds such as sulfurized C_12-24fats, alkyl sulfides and polysulfides wherein the alkyl groups contain from 1 to 8 carbon atoms, and sulfurized polyolefins also may function as friction modifiers in the lubricating oil compositions of the invention. Other function modifiers known to those skilled in the art are useful as a component of a composition according to the invention.

Base Oils

The present invention is broad with respect to the selection of base oil component used in its blending. Typically, compositions according to the invention comprise a base oil as a major component of the composition. For purposes of this specification and the appended claims the term “base oil” as used herein is intended to include those materials which are recognized as possessing lubricity characteristics by those of ordinary skill in the art. Such materials include, without limitation, materials falling within the following classes: 1) lubricity agents such as synthetic polymers (e.g., polyisobutene having a number average molecular weight in the range of about 750 to about 15,000, as measured by vapor phase osmometry or gel permeation chromatography); 2) the polyol ethers (e.g., poly(oxyethylene-oxypropylene)ethers); 3) ester oils including natural and synthetic triglycerides; 4) natural oil fractions such as mineral oils and those referred to as bright stocks (including all relatively viscous products formed during conventional lubricating oil manufacture from petroleum). Thus, any oil or other material recognized by those skilled in the art as possessing lubricity characteristics may be used as a base oil for purposes of this invention.

Ashless Dispersants

Within the prior art in the realm of motor fuel are a wide range of materials regarded as ashless dispersants by those of ordinary skill in such art. There are a great many materials capable of functioning in this regard, including various Mannich bases, ethyleneamines, polyalkylene polyamines, and other primary, secondary and tertiary amines known in the art. The following is provided to be exemplary and not delimitive of the scope of ashless dispersants which may be employed in the context of the present invention.
A large number of such ashless dispersants are derivatives of high molecular weight carboxylic acid acylating agents. Typically, the acylating agents are prepared by reacting an olefin (e.g., a polyalkene such as polybutene) or a derivative thereof, containing for example at least about 10 aliphatic carbon atoms or generally at least 30 to 50 aliphatic carbon atoms, with an unsaturated carboxylic acid or derivative thereof such as acrylic acid, methylacrylate, maleic acid, fumaric acid and maleic anhydride. Dispersants are prepared from the high molecular weight carboxylic acid acylating agents by reaction with, for example, amines characterized by the presence within their structure of at least one N—H group, alcohols, reactive metal or reactive metal compounds, and combinations of the above. The prior art relative to the preparation of such carboxylic acid derivatives is summarized in U.S. Pat. No. 4,234,435.
It also has been suggested that the carboxylic acid derivative compositions such as those described above can be post-treated with various reagents to modify and improve the properties of the compositions. Acylated nitrogen compositions prepared by reacting the acylating reagents described above with an amine can be post-treated, for example, by contacting the acylated nitrogen compositions thus formed with one or more post-treating reagents selected from the group consisting of boron oxide, boron oxide hydrate, boron halides, boron acids, esters of boron acid, carbon disulfide, sulfur, sulfur chlorides, alkenyl cyanides, carboxylic acid acylating agents, aldehydes, ketones, phosphoric acid, epoxides, etc. Lists of the prior art relating to post-treatment of carboxylic ester and amine dispersants with reagents such as those described above are contained in a variety of patents such as U.S. Pat. No. 4,203,855 (Col. 19, lines 16-34) and U.S. Pat. No. 4,234,435 (Col. 42, lines 33-46). The use of isophthalic and terephthalic acids as corrosion-inhibitors is described in U.S. Pat. No. 2,809,160. The corrosion-inhibitors are used in combination with detergent additives.
The preparation of lubricating oils containing ashless dispersants obtained by reaction of aliphatic and aromatic polycarboxylic acids with acylated amines have been described previously. For example, U.S. Pat. No. 4,234,435 describes lubricating oils containing carboxylic acid derivative compositions prepared by post-treating acylated amines with a variety of compositions including carboxylic acid acylating agents such as terephthalic acid and maleic acid. U.S. Pat. No. 3,287,271 and French Pat. No. 1,367,939 describe detergent-corrosion inhibitors for lubricating oils prepared by combining a polyamine with a high molecular weight succinic anhydride and thereafter contacting the resulting product with an aromatic dicarboxylic acid of from 8 to 14 carbon atoms wherein the carboxyl groups are bonded to annular carbon atoms separated by at least one annular carbon atom. Illustrative of such aromatic dicarboxylic acids are isophthalic acid, terephthalic acid and various derivatives thereof. Lubricating compositions containing amine salts of a phthalic acid are described in U.S. Pat. No. 2,900,339. The amine salts are thermally unstable salts of the phthalic acid and a basic tertiary amine. U.S. Pat. No. 3,692,681 describes dispersions of phthalic acid in hydrocarbon media containing highly hindered acylated alkylene polyamines. The polyamines are prepared by reaction of an alkenyl succinic anhydride with an alkylene polyamine such as ethylene polyamine or propylene polyamine. The terephthalic acid or its derivative is dissolved in an auxiliary solvent such as a tertiary alcohol or DMSO, and a terephthalic acid solution is combined with a hydrocarbon solution containing the hindered acylated amine address detergent. The auxiliary solvent then is removed.
U.S. Pat. No. 3,216,936 describes lubricant additives which are compositions derived from the acylation of alkylene polyamines. More specifically, the compositions are obtained by reaction of an alkylene amine with an acidic mixture consisting of a hydrocarbon-substituted succinic acid having at least about 50 aliphatic carbon atoms in the hydrocarbon group and an aliphatic monocarboxylic acid, and thereafter removing the water formed by the reaction. The ratio of equivalents of said succinic acid to the mono-carboxylic acid in the acidic mixture is from about 1:0.1 to about 1:1. The aliphatic mono-carboxylic acids contemplated for use include saturated and unsaturated acids such as acetic acid, dodecanoic acid, oleic acid, naphthenic acid, formic acid, etc. Acids having 12 or more aliphatic carbon atoms, particularly stearic acid and oleic acid, are especially useful. The products described in the '936 patent also are useful in oil-fuel mixtures for two-cycle internal combustion engines.
British Pat. No. 1,162,436 describes ashless dispersants useful in lubricating compositions and fuels. The compositions are prepared by reacting certain specified alkenyl substituted succinimides or succinic amides with a hydrocarbon-substituted succinic acid or anhydride. The arithmatic mean of the chain lengths of the two hydrocarbon substituents is greater than 50 carbon atoms. Formamides of monoalkenyl succinimides are described in U.S. Pat. No. 3,185,704. The formamides are reported to be useful as additives in lubricating oils and fuels.
U.S. Pat. Nos. 3,639,242 and 3,708,522 describe compositions prepared by post-treating mono- and polycarboxylic acid esters with mono- or polycarboxylic acid acylating agents. The compositions thus obtained are reported to be useful as dispersants in lubricants and fuels.
One preferred method for preparing compositions according to the invention is to begin with a major amount of a base oil material and add the other selected ingredients to the base oil, with sufficient agitation to provide a homogeneous mixture within a reasonable time. When the viscosity of the additive is much greater than that of the base oil, it is beneficial to provide heating to the base oil to facilitate dissolution and homogeneity. This is especially true in the cases where polymeric materials are added to base oils. However, the dissolution of all of the additives used in the invention in a base oil is well known in the art and is thus within the skill level of an ordinary artisan in the oil additives field.
The compositions of the present invention may vary widely in composition depending upon the intended use of the final composition. However, those of ordinary skill in formulating lubricating oils, functional fluids, cutting oils, emulsions, etc., in which LAB based detergent materials are used as a component readily recognize that the detergents prepared from LAB materials provided by the invention may be used as direct, drop-in substitutes for many detergent components in current formulations, including those which are based on linear alkylbenzenes and those which are not. Compositions which include detergents based upon the linear alkylbenzenes of the invention offer superior detergency over formulations which contain linear alkylbenzene based detergent materials of the prior art, on a molar basis, owing to the unique isomer distribution provided by the present invention.
Another aspect of the present invention is the use of the LAB surfactants in fuel formulations on which various internal combustion engines including diesel, automobile, and jet engines may be operated. Since the LAB surfactants of this invention may be anionic in nature, such as in the cases when the detergent molecule is a sulfonate, it is possible to provide charge balance using a cation which is known to impart beneficial properties to motor fuels. Such cations may include the alkali and alkaline earth metals as the use of such are well known for the properties they impart to fuel compositions. Further, the prior art discloses many ashless dispersants useful as additives in fuels and lubricant compositions. Many of these are cationic in nature and are thus capable of providing charge balance to chemical compounds in which the anionic portion is derived from the LAB according to this invention, to provide a neutral, oil or fuel soluble material which possesses both detergent and dispersant characteristics.
One particular and surprising advantage of using the catalysts of this invention to produce alkylbenzenes is that a low content of dialkylbenzene components are found in the alkylbenzene product mixture. This is important since dialkylbenzenes are generally regarded as undesirable, and the presence of such species tends to raise the viscosity of the alkylbenzene reaction product mixture. Thus, using conventional alkylation technology known in the art, it is common for alkylbenzenes produced in accordance with prior art methods to have a viscosity greater than about 145 SUS viscosity units at a temperature of 37.8 degrees centigrade. However, alkylation of benzene with olefins in the C₁₆-C₃₀range in accordance with this invention provides a product having an SUS viscosity of 85 at 37.8 degrees centigrade. Generally speaking, alkylbenzenes made by alkylation of benzene with olefins in the C₁₆-C₃₀range using catalysts an procedures taught herein results in the alkylbenzenes containing less than 1% of dialkylbenzenes.
A material sold by Huntsman LLC of Houston Tex. is sold under the trade name “Alkylate 300” and is available from Huntsman in commercial quantities. Huntsman's Alkylate 300 is has a 2-phenyl isomer content in the range of between about 10 and 13% by weight of all alkylbenzene isomers present, and is substantially free of benzene inasmuch as we are unable to detect any benzene present down to a level of 100 parts per billion.
Huntsman's Alkylate 300 is suitable for sulfonation from which alkylbenzene sulfonates may be produced using means known to those skilled in the art which may comprises reacting the Alkylate 300 with sulfuric acid and/or SO₃at elevated temperatures. A sulfonation method involving an air/sulfur trioxide mixture which is applicable to providing sulfonated Alkylate 300 is described in U.S. Pat. No. 3,427,342 to Brooks et al., entitled “Continuous Sulfonation Process,” which is incorporated by reference herein. In an embodiment, a sulfur trioxide to alkyl aromatic product molar ratio used for sulfonation is 1.03.
The sulfonated Alkylate 300 emerges from the sulfonation reactor as the acid form of the sulfonate, which is sometimes referred to as an alkylbenzenesulfonic acid. This acid may be neutralized using conventional alkalis such as hydroxides, oxides, carbonates, etc. of alkali metals, alkaline earth metals, and combinations thereof. One popular method for using Alkylate 300 is to sulfonate the Alkylate 300 to form the alkylbenzenesulfonic acid, and to subsequently neutralize the sulfonic acid so obtained with a calcium or magnesium salt, and subsequently overbasing by successive additions of carbon dioxide and magnesium and/or calcium ion until a material having a desired base number is obtained. The resulting material is an oil-soluble overbased sulfonate, which is suitable for use as a detergent additive for lubricants and oils.
Thus, a composition of one form of the present invention is a mixture of two or more alkylbenzenes which have a 2-aryl isomer content in the range of between about 8 and 30% by weight based on the total weight of all of the linear monoalkylbenzenes (including 2-aryl and non-2-aryl) present in the mixture. In general, alkylbenzenes and detergent-dispersant products derived therefrom according to this invention are substantially free from benzene, having a benzene content less than 2 ppm in one form of the invention, less than 1 ppm in another form of the invention, less than 0.5 ppm in another form of the invention and less than 100 parts per billion in another form of the invention. In general, an alkylbenzene and detergent-dispersant products derived therefrom according to the invention contain less than about 28% branching. Further, the alkylbenzenes according to the invention are substantially free from 1-aryl isomers of alkylbenzenes, which are isomers where the benzene ring is attached to the 1-position of a linear alkyl chain having more than about 14 carbon atoms.
Consideration must be given to the fact that although this invention has been described and disclosed in relation to certain preferred embodiments, obvious equivalent modifications and alterations thereof will become apparent to one of ordinary skill in this art upon reading and understanding this specification and the claims appended hereto. The present disclosure includes the subject matter defined by any combination of any one of the various claims appended hereto with any one or more of the remaining claims, including the incorporation of the features and/or limitations of any dependent claim, singly or in combination with features and/or limitations of any one or more of the other dependent claims, with features and/or limitations of any one or more of the independent claims, with the remaining dependent claims in their original text being read and applied to any independent claim so modified. This also includes combination of the features and/or limitations of one or more of the independent claims with the features and/or limitations of another independent claim to arrive at a modified independent claim, with the remaining dependent claims in their original text being read and applied to any independent claim so modified.
The present invention includes any overbased sulfonate described herein with any one or more conventional additives useful in motor oils and the like specified herein.
In addition, the 2-aryl isomer content has been described in quantities relative to the total weight of a mixture in which such isomers are present. The present invention also includes embodiments in which the percentages specified herein relate to the 2-isomer content when calculated by taking the weight of the 2-isomer content in a given sample, and dividing it by the weight in the same sample of linear alkylbenzenes, and multiplying this quotient by 100 to arrive at a percentage 2-isomers, with all remaining claim limitations held constant. A specification sheet for Alkylate 300 is available from Huntsman LLC of Houston, Tex.
Thus, the presently disclosed invention is intended to cover all such modifications and alterations, and is limited only by the scope of the claims which follow, in view of the foregoing and other contents of this specification.

Claims

1) A mixture of alkylbenzenes from which an overbased alkaline earth sulfonate may be prepared, which mixture comprises two or more 2-aryl isomers of alkylbenzenes having the structure:

in which:

n is any integer between 12 and 30;

R₁, R₂, R₃, R₄, and R₅are each independently selected from the group consisting of: hydrogen, a methyl group, an ethyl group, a propyl group, and a butyl group;

B is selected from the group consisting of: hydrogen, methyl, or ethyl;

B is attached to any single carbon atom along the —(CH₂)_n— portion of the alkyl chain; and

the total 2-aryl isomer content of said mixture of alkylbenzenes is between about 8% and about 30% by weight based on the total weight of all alkylbenzenes present in said mixture.

2) A mixture according to claim 1 which contains less than about 2 parts per million of benzene by weight based on the total weight of said mixture.

3) A mixture according to claim 1 which contains less than about 1 parts per million of benzene by weight based on the total weight of said mixture.

4) A mixture according to claim 1 which contains less than about 0.5 parts per million of benzene by weight based on the total weight of said mixture.

5) A mixture according to claim 1 which contains less than about 100 parts per billion of benzene by weight based on the total weight of said mixture.

6) A mixture according to claim 1 in which B is hydrogen for between about 72% and about 98% of all alkylbenzenes present, by weight, based on the total weight of said mixture.

7) A mixture according to claim 1 in which the amount of 1-aryl isomers present is less than about 0.3% by weight based on the total weight of said mixture.

8) A mixture according to claim 1 in which the amount of 1-aryl isomers present is any amount in the range of between about 0.01% to about 0.3% by weight based on the total weight of said mixture.

9) An overbased sulfonate made by sulfonating a mixture according to claim 1, and subsequently overbasing with an alkaline earth metal and carbon dioxide, or an alkali metal and carbon dioxide, until the base number of said overbased sulfonate is at least 250.

10) A process for producing an overbased sulfonate which comprises the steps of:

a) providing a mixture of aromatic alkylates which comprises two or more 2-aryl isomers having the structure:

in which:

n may be equal to any integer between 12 and 30;

B is selected from the group consisting of: hydrogen, methyl, or ethyl;

the 2-aryl content of said mixture of aromatic alkylates is between about 8% and about 30% by weight based on the total weight of said mixture;

said mixture contains an amount of 1-aryl isomer that is less than about 3% by weight based on the total weight of all aromatic alkylates present in said mixture; and

b) reacting said mixture of aromatic alkylates with a source of sulfur trioxide, thus yielding an alkylaryl sulfonic acid;

c) combining said alkylaryl sulfonic acid with:

i) a source of an alkaline earth metal selected from calcium, strontium, and magnesium;

ii) water;

iii) a lower alcohol;

iv) optionally, a hydrocarbon solvent; and

v) carbon dioxide,

under conditions favorable to formation of an overbased sulfonate, wherein the final overbased sulfonate has a total base number of any value in the range of about 200 to about 375.

11) A process according to claim 10 further comprising the step of: d) filtering said overbased sulfonate to remove solids.

12) A process according to claim 11 further comprising the step of: e) diluting said overbased solvent with a material selected from the group consisting of: a hydrocarbon solvent and a base oil.

13) A process according to claim 10 in which said mixture of aromatic alkylates contains less than about 2 ppm benzene.

14) A process according to claim 10 in which said mixture of aromatic alkylates contains less than about 1 ppm benzene.

15) A process according to claim 10 in which said mixture of aromatic alkylates contains less than about 0.5 ppm benzene.

16) A process according to claim 10 in which said mixture of aromatic alkylates contains less than about 0.3% by weight of 1-aryl isomers of alkylbenzenes.

17) A composition useful as a lubricant, which composition is formed by mixing a base oil with an effective detergent-dispersant amount of an alkylbenzene-derived detergent component that is made by sulfonating, and optionally overbasing, a mixture of alkylbenzenes, which mixture comprises two or more 2-aryl isomers of alkylbenzenes having the structure:

in which:

n is any integer between 12 and 30;

B is selected from the group consisting of: hydrogen, methyl, or ethyl;

18) A composition according to claim 17 wherein said mixture of alkylbenzenes contain any amount between about 10% and about 20% of said 2-aryl isomers, by weight, based on the total weight of all alkylbenzenes present in said mixture.

19) A composition according to claim 17 in which said mixture of alkylbenzenes contain less than about 2 ppm of benzene by weight.

20) A composition according to claim 17 in which said mixture of alkylbenzenes contain less than about 1 ppm of benzene by weight.

21) A composition according to claim 17 in which said mixture of alkylbenzenes contain less than about 0.5 ppm of benzene by weight.

22) A composition according to claim 17 wherein said alkylbenzene-derived detergent component is present in any amount between 0.03% and 49.95% by weight based upon the total weight of said composition useful as a lubricant.

23) A composition as in claim 17 wherein the alkylbenzene-derived detergent component is predominantly comprised of molecules which comprise only one alkyl group bonded to a benzene ring, and wherein none of R₁, R₂, R₃, R₄, or R₅are hydrocarbyl.

24) A composition as in claim 23 wherein the alkyl group is substantially linear.

25) A composition as in claim 23 wherein the alkyl group is a branched alkyl group.

26) A composition according to claim 17 wherein said alkylbenzene-derived detergent component is present in any amount between 0.10% and 25.00% by weight based upon the total weight of said composition useful as a lubricant.

27) A composition according to claim 17 in which said mixture of alkylbenzenes contains less than about 0.3% by weight 1-aryl isomers of alkylbenzenes.

28) A composition according to claim 17 in which the 1-aryl alkylbenzenes isomers content of said mixture of alkylbenzenes is any value in the range of between about 0.01% and about 0.3% by weight based on the total weight of said mixture.

29) A composition useful as a lubricant that is formed from components comprising:

a) an alkylbenzene-derived component present in any amount between about 0.01% and about 50% by weight based upon the total weight of the composition, which alkylbenzene-derived component is selected from the group consisting of: sulfonates and overbased sulfonates of an alkylbenzenes mixture in which the content of 2-aryl isomers in said alkylbenzenes mixture is any value between about 10% and about 30% by weight based on the total weight of the alkylbenzenes mixture, wherein said 2-aryl isomers are described by the general formula:

in which n is equal to any integer between about 14 and about 27, and in which one and only one of R₁, R₂, R₃, R₄, and R₅is a sulfur-containing appendage selected from the group consisting of: a sulfonic acid group, a sulfonate group, and a sulfonate ester group; and

wherein the groups R₁, R₂, R₃, R₄, and R₅which are not a sulfur-containing group are each independently selected from the group consisting of: hydrogen, a methyl group, an ethyl group, a propyl group, and a butyl group; and

b) at least 50% by weight of a base oil,

wherein said alkylbenzene-derived component contains one or more metals selected from the group consisting of: lithium, sodium, potassium, strontium, magnesium, and calcium.

30) A composition according to claim 29 in which said alkylbenzene-derived component is a mixture of sulfonate salts of metals selected from the group consisting of: alkali metals or alkaline earth metals.

31) A composition according to claim 29 in which said alkylbenzene-derived component is an overbased sulfonate which comprises a mixture of isomers of alkaline earth metal alkylbenzene sulfonates, which mixture includes one or more metals selected from the group consisting of: Sr, Mg, Ba, and Ca.

32) A composition according to claim 29 in which said alkylbenzene mixture contains less than about 2 parts per million of benzene by weight based on the total weight of said alkylbenzene mixture.

33) A composition according to claim 29 in which said alkylbenzene mixture contains less than about 1 parts per million of benzene by weight based on the total weight of said alkylbenzene mixture.

34) A composition according to claim 29 in which said alkylbenzene mixture contains less than about 0.5 parts per million of benzene by weight based on the total weight of said alkylbenzene mixture.

35) A composition according to claim 29 in which said alkylbenzene mixture contains less than about 100 parts per billion of benzene by weight based on the total weight of said alkylbenzenes mixture.

36) A composition according to claim 29 in which B is hydrogen for between about 72% and about 98% of all alkylbenzenes present in said alkylbenzene mixture, by weight, based on the total weight of said alkylbenzenes mixture.

37) A composition according to claim 29 in which the amount of 1-aryl isomers present in said alkylbenzene mixture is less than about 0.3% by weight based on the total weight of said alkylbenzenes mixture.

38) A composition according to claim 29 in which the amount of 1-aryl isomers present in said alkylbenzene mixture is any amount in the range of between about 0.01% to about 0.3% by weight based on the total weight of said alkylbenzenes mixture.

39) A composition of matter comprising:

a) a major amount of a material selected from the group consisting of: a motor fuel, a hydrocarbon diluent, or a base oil; and

b) a minor amount of a mixture of alkaline earth metal salts of overbased alkylbenzene sulfonates, which mixture comprises two or more 2-aryl isomers of overbased alkylbenzene sulfonates which are derived from a mixture of alkylbenzene sulfonates comprising at least two 2-aryl isomers of the structure:

in which:

n is any integer between about 12 and about 30;

R₁, R₂, R₃, R₄, and R₅are each independently selected from the group consisting of: hydrogen, a methyl group, an ethyl group, a propyl group, a butyl group, a sulfonic acid group, and a sulfonate group;

B is selected from the group consisting of: hydrogen, methyl, or ethyl;

the total 2-aryl isomer content of said mixture of overbased alkaline earth sulfonates is between about 8% and about 30% by weight based on the total weight of all overbased alkylbenzene sulfonates present in said mixture, and in which the 1-aryl isomer content is less than about 3% by weight based on the weight of all isomers of overbased alkylbenzene sulfonates present, subject to the proviso that the sulfate or sulfonic acid group which is overbased is located at least one of R₁, R₃, and R₅.

40) A composition according to claim 39 in which B is hydrogen for between about 72% and about 98% of all overbased alkylbenzene sulfonates present, on a molar basis.

41) A composition according to claim 39 in which the amount of 1-aryl isomers present is less than about 0.3% by weight based on the total weight of all overbased sulfonates present.

42) A composition according to claim 39 in which the amount of 1-aryl isomers present is any amount in the range of between about 0.01% to about 0.3% by weight based on the total weight of all overbased sulfonates present.

43) A concentrate which comprises:

a) an alkylbenzene-derived detergent component, said component characterized as comprising any amount between about 10% and about 30% by weight based upon the total weight of the component, of derivatives of at least two different 2-aryl isomers of alkylbenzenes described by the general formula:

wherein n is equal to any integer between 14 and 28, and in which R₁, R₂, R₃, R₄, and R₅are each independently selected from the group consisting of: hydrogen, a methyl group, an ethyl group, a propyl group, a butyl group, a sulfonic acid group, a sulfonate group, and a sulfonate ester group; and

b) a base oil.

44) A concentrate according to claim 43 in which the content of detergents which are derived from 1-aryl alkylbenzene isomers is less than about 0.3% by weight based on the total weight of all alkylbenzene-derived detergents present.

45) A concentrate according to claim 43 in which the content of detergents which are derived from 1-aryl alkylbenzene isomers is any amount between about 0.01% and about 0.03% by weight based on the total weight of all alkylbenzene-derived detergents present.

46) A composition of matter according to claim 43 wherein the viscosity of the alkylbenzene mixture is less than 140 SUS units at 37.8 degrees centigrade.

47) A mixture according to claim 43 wherein the viscosity of the mixture is less than 120 SUS units at 37.8 degrees centigrade.

48) A mixture according to claim 43 wherein the viscosity of the alkylbenzene mixture is less than 100 SUS units at 37.8 degrees centigrade.

49) The process of providing a metal surface with a lubricating film comprising the step of contacting a composition according to claim 43 to said metal surface.