FIELD OF THE INVENTION

The present invention relates generally to a dehydro¬ halogenation process and the products obtained therefrom. In accordance with the process, halogen is removed from an alkylene/sulfur halide complex. More specifically, the invention relates to a process for the dehydrochlorination of an isobutylene/sulfur chloride complex and the dechlorinated product (i.e., the sulfurized olefin) obtained from such a process, as well as lubricants and concentrates containing the product as a performance improving additive.

BACKGROUND OF THE INVENTION

Sulfurized olefin compounds are widely produced and are known to be effective extreme pressure agents or load carrying additives for lubricating oils. (See U.S. Patent 3,703,504; 3,697,499 and 3,471,404.) These sulfurized olefins may be obtained by sulfohalogenating a hydrocarbon olefin with a sulfur halide such as a sulfur chloride to form an alkylene sulfohalogenated complex. This complex can be further sulfurized such as by treating with an aqueous alkali metal monosulfide solution (see U.S. Patent

3,703,504) and dehalogenating.

U.S. Patent 4,200,546 discloses a process wherein sulfurized olefins are obtained via a process which

comprises sulfohalogenating an olefin with a sulfur halide in the presence of a catalytic quantity (i.e., 0.2-10 wt.% based on the halide) of a lower aliphatic alcohol having up to about 10 carbon atoms (e.g., methanol, ethanol, propanol, i-propanol, butanol, i-butanol, etc.) to form a sulfohalogenated organic intermediate, and thereafter sulfurizing and dehalogenating said intermediate in the presence of a substantial quantity of lower aliphatic alcohol, e.g., from 10 to about 50% by weight of the adduct by treatment with an aqueous alkali metal sulfide solution, or an aqueous alkali metal monosulfide solution (which can be derived, for example, from a spent aqueous alkali metal hydroxide effluent from hydrocarbon purifica¬ tion) having a substantial combined sulfur content, thus producing an organic sulfide of high combined sulfur content.

U.S. Patent 3,703,504, like the above referred to patent, discloses a process which comprises sulfohalo¬ genating- an olefin. The process is carried out with a sulfur halide in the presence of a catalytic quantity of a lower aliphatic alcohol to form a sulfohalogenated organic intermediate, and thereafter sulfurizing and dehalo¬ genating said intermediate in the presence of a substan¬ tial quantity of a lower aliphatic alcohol by treatment with an aqueous alkali metal mcnosulfide solution derived from a spent aqueous alkali metal hydroxide effluent from hydrocarbon purification and having a substantial combined sulfur content in producing an organic sulfide of high combined sulfur content. U.S. Patent 1,706,724 discloses a process comprising (1) preparing a catalyzed chlorinated polyolefin by substantially uniformly admixing from about 0.25 to 0.5 part by weight ^' of a Lev/is acid per 100 parts of a com¬ minuted chlorinated polyolefin (phr.), (2) maintaining the catalyzed chlorinated polyolefin in the form of a fluid- iz-ed bed in the presence of a substantially inert gas and further in the presence of from about 2 to 5 phr. of an inert filler which has an affinity for adsorption onto the surfaces of the chlorinated polyolefin, (3) heating the

fluidized bed to a temperature sufficient to produce the dehydrochlorination reaction without burning or charring the chlorinate polyethylene being dehydrochlorinated, then

. (4) cooling the fluidized bed and recovering the dehydro- chlorinated product.

U.S. Patent 3,862,991 discloses a bis(beta-chloro- beta-arylaklyl)disulfide, which is made by reacting sulfur monochloride with a beta-arylolefin selected from the group consisting of styrene, alpha-methyl styrene, p- tert-butyl styrene, o-chlorostyrene, p-chlorostyrene, vinyltoluene, anethole, 1,2-dihydroanaphthalene, acenaphthalene, 1-phenylcyclohexane and indene.

U.S. Patent 2,322,258 discloses heating an olefin with a solution of potassium hydroxide in a monohydric alcohol such as ethanol. Polyhydric alcohols and hydroxy ethers are used for splitting a hydrogen halide from the molecule of a halogenated organic compound with an alkali. By carrying such reaction out in the presence of a polyhydric alcohol or a hydroxy ether, either sodium hydroxide or potassium hydroxide may be used as the alkaline reactant and the latter may be employed in solid form or dissolved in an alcohol or water, as desired.

SUMMARY OF THE INVENTION The invention generally relates to a dehydrohalogena- tion process whereby halogens are removed from the reac- tion product obtained when sulfurizing an olefin with a sulfur halide. For example, the invention includes a process whereby chlorine is removed from the reaction product obtained by sulfurizing an olefin with a sulfur chloride. In accordance with the process of this inve¬ ntion, an olefin such as isobutene is reacted with a sulfur chloride to obtain an isobutene sulfur chloride complex. The complex obtained is then contacted with a protic solvent such as water and isopropyl alcohol in the absence of any metal, providing a sulfurized olefin

product which is substantially free of chlorine or any ash (metal) containing contaminants.

A primary object of this invention is to provide an improved.dehydrohalogenation process. Another object is to provide an improved method for obtaining a sulfurized olefin composition.

Another object of this invention is to provide a sulfurized olefin product produced by utilizing an improved dehydrochlorination process. A feature of the process of the present invention is that dehydrochlorination can be carried out in a manner which reduces waste by-products such as ash (metal) containing contaminants.

An advantage of this invention is that it provides a dehydrohalogenation process .which can be carried out in a simple, economical and environmentally advantageous manner.

Another feature of this invention is that sulfurized olefin compositions obtained can be used in various lubricant oils and functional fluids.

These and other objects, advantages and features of the present invention will become apparent to those persons skilled in the art upon reading the details of the method, structure and usage as more fully set forth below. Reference being made to the accompanying general structural formulae forming a part hereof wherein like symbols refer to like molecular moieties throughout.

In order to clearly describe and disclose the present invention some of the terms used in the description and claims will be specifically defined. The dehydrohalogen¬ ation step of the invention may be carried out "in the absence of any metal ions." This is intended to indicate that no metal contaminant salts which might form metal ions are added to the reaction. However, some contaraina- nts may be present in trace amounts. The amounts of metal ions present would be expected to vary depending on the reactants used and their purity. In one embodiment of the invention dehydrohalogenation may be carried out "in the

presence of a catalytic amount of metal ions." This is intended to mean that metal ions are present in less than molar, amounts based on the molar amount of complex being dehydrohalogenated and further that the catalytic amount present is present in its original form and amount at the end of the reaction, i.e. the catalytic amount does not alter the final product but only affect ^' s the rate of reaction. The term "ash containing" is a term of art meaning metal containing.

DETAILED DESCRIPTION OF THE

PREFERRED EMBODIMENTS OF THE INVENTION

Before the present dehydrohalogenation process is described, it is to be understood that this invention is not limited to the particular compounds or process steps described as . such compounds and methods may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting since the scope of the present invention will be limited only by the appended claims.

A unique composition of sulfurized olefins is pro¬ duced by a process in accordance with the present inven¬ tion. Although some of the molecules of the composition are themselves known, the composition itself is a unique blend of molecules, which blend can only be obtained by the process of the present invention. The complexity of this unique blend of molecules requires such be described in terms of the process by which such is produced and/or by spectrographic analysis. The unique composition of the present invention is produced by the present inventive process which is sur¬ prisingly simple, efficient and economical. In general, the present process involves combining an olefin with a sulfur halide compound to obtain an alkylene sulfur halide complex. The reaction product complex obtained is then subjected to a protiσ solvent in the absence of any metal, i.e., ash producing component. The halogens are thereby

removed from the reaction product leaving a sulfurized olefin composition of unique character.

An embodiment of the present invention as applied to specific molecules can be describes as a dehydrochlor- ination process of an isobutylene/sulfur monochloride complex, which complex is the reaction product obtained by reacting isobutylene with sulfur monochloride. The dehydrochlorination of the reaction product is carried out by subjecting this reaction product (i.e., isobutylene/ sulfur monochloride complex) to heat in the presence of a protic solvent (preferably acetic acid, isopropanol and/or H ₂ 0) with or without a catalyst in order to effect dehydrochlorination. This step removes a substantial amount of the chlorine and the product is useful in this form without further processing. However, the product can be isolated and this step repeated in order to remove any remaining chlorine. Alternatively, sodium hydroxide and/or Na_S is added in order to remove any remaining chlorine. After the chlorine has been removed, the product may be further sulfurized by contacting the product with elemental sulfur in the presence of heat and a catalyst. After the initial contact is carried out, further processing may not be required if the halide content has been reduced to less than the desired maximum level, e.g. about 0.5% by weight.

The essence of the invention is a dehydrohalogenation step. This step is generally carried out as a part of a process for producing a sulfurized olefin. The process

-generally involves reacting an olefin with a sulfur halide to obtain an alkyl/sulfur halide complex. This complex is contacted with a protic solvent to carry out dehydroha¬ logenation of the complex. A sulfurized product is obtained which is substantially free of any halide, i.e. the product obtained has had enough of the halide removed so that it is useful as a lubricant additive. In some cases the sulfurized product can be isolated and used as is after a single contact. However, it is preferably subjected to further dehydrohalogenation via (1) again contacting with a protic solvent, e.g. an additional

charge of water or (2) contacting with an inorgani caustic, for example, sodium hydroxide, Na ₂ S _χ and others. A very specific example of how the entire process might be. carried out is shown below with reference to specific compounds and structures. Again the present invention is in no way restricted to the specific compound or steps shown below. It should be noted that hydrogens sufficient to satisfy carbon valences are present.

Step #1

isobutene sulfur monochloride

The reaction products are isobutylene/sulfur chloride complexes in a variety of forms, the structure of one such complex might be as follows:

C C

I I

Cl-C-C-S-S-C-C-Cl

I I

C c

Step #2 isobutylene/sulfur chloride complex + protic solvent (e.g., isopropyl alcohol) heat

The reaction products are dehydrochlorinated compounds in a variety of forms, the structure of one such compound might be as follows:

C C II ii

C-C-S-S-C-C l i

C C

The resulting sulfurized compound is substantially free of chlorine.

Optional Steps

Isolate the sulfurized compound and add an inorganic caustic such as NaOH and/or Na ₂ S _χ (wherein x is generally 1 or 2) to remove remaining Cl or isolate the sulfurized 5 compounds and repeat the dehydrohalogenation step, i.e. repeat step #2 above. In step #2 the protic solvent may be water. After the first contact with water, phase separation can be carried out to remove the water and ad-ditiona-1 water added. Then the additional water can be

TO:- removed and a dehydrating catalyst added and the mixture heated under vacuum, e.g. add a sulfonated polystyrene such, as Amberlyst 15.

Essential features of this specific embodiment of the invention are (1) contacting the isobutylene/sulfur

15 monochloride complex with the protic solvent in the presence of heat in order to effect dehydrochlorination; and (2) carrying out dehydrohalogenation without the use of a metal containing reactant. These procedures increase the efficiency of the dehydrochlorination

20 process and substantially eliminate ash containing waste products.

A wide variety of olefinic substances may be charged tσ the initial sulfochlorination reaction including hydrocarbon olefins having a single double bond with

2.5; terminal or internal double bonds and containing from about: 2 to 30 or more, preferably 2 to 8 carbon atoms per mαl'ecjule in either straight, branched chain or cyclic compounds^ and these may be exemplified by ethylene, propylene, butene-1, cis and trans butene-2, isobutylene,

30 diisobutylene, triisobutylene, pentenes, . cyclopentene, cyclohexene, the octenes, decene-1, etc. In general, C, ₆ olefins or mixtures thereof are desirable for preparing sulfurized products for use as extreme pressure additives as the combined sulfur content of the product decreases

35. ^" with increasing carbon content yet its miscibility with oil is lower for propylene and ethylene derivatives.

In some embodiments of the invention, isobutylene is

particularly preferred as the sole olefinic reactant, but it may be employed, desirably in major proportion, in mixtures containing one or more other olefins; moreover, the charge may contain substantial proportions of saturat- ed aliphatic hydrocarbons as exemplified by methane, ethane, propane, butanes, pentanes, etc. Such alkanes are preferably present in minor proportion in most instances to avoid unnecessary dilution of the reaction, since they neither react nor remain in the products but are expelled in the off-gases or by subsequent distillation. However, mixed charges can substantially improve the economics of the present process since such streams are of lower value than a stream of relatively pure isobutylene.

The other reactant in the first stage is the sulfur- izing agent. This agent may be selected from compounds such as sulfur monochloride (S ₂ C1 ₂ ) ; sulfur dichloride; and S,C1- as well as the corresponding but more expensive sulfur bromides. The sulfurizing agent may be employed in an amount which will provide the desired quantity of sulfur. The amount of sulfurization desired will vary depending on the end use of the product and can be determined by one of ordinary skill in the art. The molar ratio of olefin to sulfur halide will vary depending on the amount of sulfurization desired in the end product and the amount of olefinic unsaturation. The molar ratio of sulfur halide to olefin could vary from l:(l-20). When the olefin to be _^ sulfurized contains a single double bond, one mole of the olefin can be reacted with 0.5 moles or less of ^S 2 ^C ^2 (sulfur monochloride) . The olefin is generally added in excess with respect to the amount of the sulfur being added so that all of the sulfur halide will be reacted and any unreacted olefin can remain as unreacted diluent oil or can be removed and recycled.

An olefin or mixture of olefins and a sulfur halide or mixture of sulfur halides are sufficiently reacted to form an olefin/sulfur halide complex. The reaction product is brought into contact with a protic solvent. The protic

solvent may be water alone or a combination of water with a lower aliphatic alcohol or carboxylic acid containing from 1 to 18 carbon atoms, as exemplified by methanol, ethanol, propanol and isopropanol, hexanol and acetic acid. Of these, methanol, isopropanol and acetic acid are usually preferred. A solvent in amounts ranging from about 10 to 90% of the weight of the total solution may be utilized, but quantities on the order of 20 to 80% are usually preferred. The molar ratio of the protic solvent to the olefin/sulfur halide complex may range from (1-10) : (1-10) but is preferably (1-5) : (5-10) and more preferably about (1) : (1) .

The solvolytic dehydrohalogenation step of the invention is carried out in the absence of ash containing (metal) contaminants. It is understood that small amounts of such contaminants may incidentally be present as impurities in one or more of the reactants. The protic solvent must thoroughly interact with the reaction product (i.e., the product obtained by reacting the olefin and sulfur halide) in an environment maintained completely free of all metal, i.e., free of all ash producing metal ions such a sodium ions. The protic solvent interacts with the olefin/sulfur ^• halide complex and results in solvolytic dehydrohalogenation which removes 90% or more of the halide in the form of an acid HX where X is a halide such as chlorine or bromine.

Accordingly, the solvolytic dehydrohalogenation is affected by the protic solvent resulting in a composition of sulfurized olefin which is substantially free of halide and any ash containing contaminants. Remaining halide can then be removed by the addition of compounds classified as "inorganic caustics" or by isolating the sulfurized olefin and repeating the solvolytic dehydrohalogenation one or more times. When the chlorine has been reduced to the selected level, the reaction mixture is allowed to stand and separate into an aqueous hydrogen chloride layer and another liquid layer containing the desired organic

sulfide product. The product is usually dried by heatin at moderately elevated temperatures under subatmospheri pressure, and its clarity may often be improved b filtering the dried product through a bed of bauxite, cla or diatomaceous earth particles.

The following examples are provided so as to provide those of ordinary skill in the art with a complete dis¬ closure and description of how to make the compounds and compositions of the invention and are not intended to limit the scope of what the inventors regard as their invention. Efforts have been made to insure accuracy with respect to numbers used (e.g. amounts, temperature, etc.) but some experimental errors and deviation should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in degrees C, and pressure is at or near atmospheric. When.considering the following Examples it will become apparent to those skilled in the art that the initial reaction product obtained by reacting the olefin and the sulfur monochloride could be modified in a number of ways. For example, different olefins and/or mixtures of olefins could be used as could different sulfurizing agents. Further, the reaction could be carried out in the presence of a number of different catalysts.

EXAMPLE 1

Add to a four neck flask about 375 grams (3 molar equivalents) of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 138 grams (3 molar equivalents) of formic acid. Heat to about 80°C and purge the mixture with nitrogen bubbling. Continue for about 5 to 6 hours or until the total theoretical amount (about 109.5g) of HC1 has evolved off. Remove the formic acid by distilling at subatmospheric pressure. Filter and obtain sulfurized isobutylene product.

EXAMPLE 2 Add to a four neck flask about 5 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 5 molar equivalents of formic acid. Heat to a temperature in the range of from about 60°C to about 160°C and purge the mixture with nitrogen bubbling. Continue for about 2 to 10 hours until the total theoretical amount of HCl has evolved off. Remove the formic acid by distilling at subatmospheric pressure. Filter and obtain sulfurized isobutylene product.

EXAMPLE 3 Add to a four neck flask about one molar equivalent of the reaction product obtained by reacting 1-pentene and sulfur monochloride. Then add about one molar equivalent of formic acid. Heat to about 80°C and purge the mixture with nitrogen bubbling. Continue for about 5 to 6 hours or until the total theoretical amount of HCl has evolved off. Strip and filter to obtain sulfurized product.

EXAMPLE 4

Add to a four neck flask about 2 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 2 molar equivalents of acidic acid. Heat to about 80°C and purge the mixture with nitrogen bubbling. Continue for about 5 to 6 hours or until the total theoretical amount of HCl has evolved off. Strip and filter to obtain sulfurized isobutylene product.

EXAMPLE 5 Add to a four neck flask about 10 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 10 molar equiva¬ lents of ethanol. Heat to about 80°C and purge the mixture with nitrogen bubbling. Continue for about 4 to 8 hours or until the total theoretical amount of HCl has evolved off. Strip and filter to obtain sulfurized isobutylene product.

EXAMPLE 6

Add to a four neck flask about 1 molar equivalent of the reaction product obtained by reacting 1-pentene and sulfur monochloride. Then add about 1 molar equivalent of acidic- acid. Heat to about 80°C and purge the mixture with nitrogen bubbling. Continue for about 2 to 7 hours or until the total theoretical amount of HCl has evolved off. Strip and filter to obtain sulfurized product.

EXAMPLE 7 Add to a four neck flask about 2 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about one molar equivalent of ethanol and one molar equivalent of water. Heat to about 100°C and purge the mixture with nitrogen bubbling. Continue for about 4 to 8 hours or until the total theoretical amount of HCl has evolved off. Strip and filter to obtain sulfurized isobutylene product.

EXAMPLE 8 Add to a four neck flask about 5 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 5 molar equivalents of formic acid and about 0.5 molar equivalents of ZnCl ₂ as catalyst. Heat until boiling and purge the mixture with nitrogen bubbling. Continue for about 2 to 4 hours until the total theoretical amount of HCl has evolved off. Strip and filter to obtain sulfurized isobutylene product.

EXAMPLE 9

Add to a four neck flask about one molar equivalent of the reaction product obtained by reacting 1-pentene and sulfur monochloride. Then add about one molar equivalent of formic acid and about 0.25 molar equivalents of ZnCl- as catalyst. Heat to about 80°C and purge the mixture with nitrogen bubbling. Continue for about 1 to 3 hours or until the total theoretical amount of HCl has evolved off. Strip and filter to obtain sulfurized product.

EXAMPLE 10 Add to a four neck flask about 2 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 2 molar equivalents of water and 0.5 molar equivalents of ZnCl^as catalyst. Heat to about 100°C and purge the mixture with nitrogen bubbling. Continue for about 2 to 4 hours or until the total theoretical amount of HCl has formed off. Separate, strip and filter to obtain sulfurized isobu¬ tylene product.

EXAMPLE 11 Add to a four neck flask about 10 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 5 molar equiva¬ lents of ethanol and 6 molar equivalents of water. Heat until boiling and purge the mixture with nitrogen bubbling. Continue for about 4 to 8 hours until the total theoretical amount of HCl has evolved off. Strip, filter and obtain sulfurized isobutylene product.

EXAMPLE 12

Add to a four neck flask about 1 molar equivalent of the reaction product obtained by reacting 1-pentene and sulfur monochloride. Then add about 0.25 molar equiva¬ lents of normal butanol and 0.65 molar .equivalents of water. Heat to boiling and purge the mixture with nitrogen bubbling. Continue for about 4 to 8 hours or until HCl is no longer being evolved off. Strip, filter and obtain sulfurized product which will include some chlorine.

EXAMPLE 13

Add to a four neck flask about 2 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 2 molar equivalents of ethanol and two molar equivalents of water and 0.03 molar equivalents of H-PO. as catalyst. Heat to about 100°C and purge the mixture vrith nitrogen bubbling. Continue for about 4 to 8 hours or until the total theo¬ retical amount of HCl has evolved off. Strip, filter and obtain sulfurized isobutylene product.

EXAMPLE 14 Add to a four neck flask about 5 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 8 molar equivalents of a yl alcohol. Heat to boiling to purge the mixture with nitrogen bubbling. Continue for about 5 to 7 hours until the total theoretical amount of HCl has evolved off. Strip, filter and obtain sulfurized isobutylene product.

EXAMPLE 15 Add to a four neck flask about one molar equivalent of the reaction product obtained by reacting 1-pentene and

^* sulfur monochloride. Then add about one molar equivalent of water. Heat to about 100°C and purge the mixture with nitrogen bubbling. Continue for about 5 to 10 hours or until the total theoretical amount of HCl has formed.

Separate, strip, filter and obtain sulfurized product.

EXAMPLE 16

Add to a four neck flask about 2 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 30 molar equivalents of water. Heat to about 100°C and purge the mixture with nitrogen bubbling. Continue for about 2 to 4 hours or until the total theoretical amount of HCl has formed.

Separate, strip, filter and obtain sulfurized isobutylene product.

EXAMPLE 17 Add to a four neck flask about 2 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 20 molar equivalents of water. Heat to about 100°C and purge the mixture with nitrogen bubbling and continue heating for 2 to 4 hours. Allow for phase separation and then remove the water. Add an additional 20 molar equivalents of water and heat to 100°C for 6 to 18 hours. Again allow for phase separation and remove the water. Add a de¬ hydrating catalyst (e.g. Amberlyst 15) and heat under vacuum to 100°C for about 1 to 2 hours. Separate, strip, filter and obtain product.

EXAMPLE 18 Add to a four neck flask about one molar equivalent of the reaction product obtained by reacting 1-pentene and sulfur monochloride. Then add about 0.5 molar equivalents of water. Heat to about 100°C and purge the mixture with nitrogen bubbling and maintain for about 5 to 10 hours. Allow for phase separation and remove water. Add a dehydrating catalyst in the form of a sulfonated polystyrene and heat under vacuum to 100°C for 2 to 4 hours. Strip, filter and obtain sulfurized product.

EXAMPLE 19 Add to a four neck flask about 2 molar equivalents of the reaction product obtained by reacting isobutylene and sulfur monochloride. Then add about 30 molar equivalents of water. Heat to about 100°C and purge the mixture with nitrogen bubbling. Allow for phase separation and remove the water. Add another 30 molar equivalents of water and heat for 5 to 10 hours at about 100°C. Strip, filter and obtain sulfurized isobutylene product.

EXAMPLE 20

Add to a four neck flask about one molar equivalent of the reaction product obtained by reacting a mixture of alpha-olefins (3-7 carbons) and sulfur monochloride. Then add about one molar equivalent of water. Heat to about 100 ^β C and purge the mixture with nitrogen bubbling for about 5 to- 10 hours. Allow for phase separation and remove water. Add 10 molar equivalents of water and heat to about 100°C for about 12 to 24 hours. Allow for phase separation and remove water. Add a dehydrating catalyst in the form of a sulfonated polystyrene and heat under vacuum at about 100°C for 2 to 10 hours. Strip, filter and obtain product.

EXAMPLES 21-40 The sulfurized product obtained from examples 1-20 can be added to an oil of lubricating viscosity. The amount of the sulfurized product being added to the oil will vary depending on the need of the lubricant and can be readily adjusted by one skilled in the art. The amount added might vary from 0.1 to 10%, preferably 0.25% to 5%, more preferably about 1% to 3% by weight based on the weight of the oil.

While the process of the present invention has been described in detail in conjunction with the treatment of a limited number of reactants under similar conditions for the purposes of valid comparisons and of fully illustrat¬ ing this invention, it will be readily apparent to those skilled in the art that numerous modifications and varia¬ tions of the process relative to specific reactants, and reaction conditions are within the purview of this inven-

tion. Accordingly, the present invention should not be construed as limited in any particulars except as may be set forth in the appended claims or required by the prior art. For example, a variety of different temperatures, times, pressures and protic solvents or mixtures thereof could be used and various adjustments may be required in order to carry out the process on a manufacturing scale.