Styrene-diene polymer viscosity modifiers for environmentally friendly fluids

Abstract

 A composition is disclosed which comprises

(A) a major amount of at least one natural oil or synthetic triglyceride of the formula

wherein R¹, R² and R³ are aliphatic groups that contain from about 7 to about 23 carbon atoms, and

(B) a minor amount of a composition comprising a hydrogenated aliphatic conjugated diene/mono-vinyl aromatic random block copolymer. In addition to components (A) and (B), the compositions may also contain

(C) an oxidation inhibitor, (D) an extreme pressure/anti-wear additive or mixtures thereof.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to natural oils or synthetic triglycerides that contain a styrene-diene viscosity modifier. The styrene-diene viscosity modifier is soluble in the natural oil and the synthetic triglyceride. Natural oils and synthetic triglycerides that contain the styrene-diene viscosity modifiers have utility in environmentally friendly farm tractor lubricants and chain bar lubricants and hydraulic fluids.

BACKGROUND OF THE INVENTION

[0002] Successful use of vegetable oils and other biodegradable oils as environmentally friendly base fluids in industrial applications is contingent on improving their viscometries and low temperature flow properties. For example, a sunflower oil containing an oleic acid content of 80 percent has a pour point of -12°C and turns solid in the Brookfield viscosity measurement. Many of the industrial applications require a pour point of less than -25°C and a Brookfield viscosity of 7500 to 150,00 centipoises (cP) at -25°C.

[0003] A key to utilizing a polymer for the thickening of a base oil is that the polymer be soluble in the base oil. This solubility problem is not present for polymers in mineral oil. Natural oils and synthetic triglycerides is another matter. In fact, it is very difficult in finding hydrocarbon polymers that are soluble in natural oils and synthetic triglycerides. Hydrocarbon polymers insoluble in natural oils and synthetic triglycerides are olefin copolymers (OCP), ethylene-propylene diene monomer (EPDM), high molecular weight polybutylene (PBU) and butyl rubbers. The present invention relates to hydrogenated random block styrene/diene polymers that are soluble in natural oils and synthetic triglycerides.

[0004] U.S. Patent No. 2,336,195 (Sparks et al, December 7, 1943) relates to improving viscosity characteristics of hydrocarbon oils by the addition of normal mono-olefin polymers. A normal mono-olefin polymer is converted to a high molecular weight polymer by compressing an olefin, such as ethylene or propylene, to a high superatomspheric pressure in excess of 500 atmospheres.

[0005] U.S. Patent No. 3,554,911 (Schiff et al, January 12, 1971) relates to improved lubricating oils, particularly mineral lubricating oils, and processes of preparing the same. In another aspect, this reference relates to the addition of a small amount of a hydrogenated random butadiene-styrene copolymer to lubrication oils to produce formulations that are shear stable and have a high viscosity index (V.I.). Accordingly, this reference relates to hydrogenated random butadiene-styrene copolymers having defined amounts of butadiene and styrene which are blended with suitable mineral oils to increase the viscosity and improve the viscosity index.

[0006] U.S. Patent No. 3,772,169 (Small et al, November 13, 1973) provides an oil composition which comprises:

1. a lubricating oil,

2. a random copolymer of butadiene and styrene containing 30-44 percent weight of units derived from butadiene and 56 - 70 percent weight of units derived from styrene, which copolymer has been hydrogenated until at least 95 percent of the olefinic double bonds and at most 5 percent of the aromatic unsaturation has been saturated, and

3. an oil - soluble polyester which comprises molecular unit derived from an alkyl ester of an α - olefinically unsaturated carboxylic acid in which the alkyl chain or chains contain(s) at least 7 carbon atoms.

[0007] U.S. Patent No. 3,772,196 (St. Clair et al, November 13, 1973) provides for lubricating oil compositions for internal combustion engines that have unexpectedly wide temperature operating characteristics. This composition contains a combination of a 2-block copolymer comprising a first polymer block of an alkenyl arene, e.g., styrene and a second essentially completely hydrogenated polymer block of isoprene and certain pour point depressants in a lubricant base stock having a viscosity index of at least 85

SUMMARY OF THE INVENTION

[0008] A composition is disclosed which comprises

(A) a major amount of at least one natural oil or synthetic triglyceride of the formula

wherein R¹, R² and R³ are aliphatic groups that contain from about 7 to about 23 carbon atoms, and

(B) a minor amount of a composition comprising a hydrogenated aliphatic conjugated diene/mono-vinyl aromatic random block copolymer.

[0009] Various preferred features and embodiments of the present invention will now be described by way of non-limiting example.

(A) The Natural Oil Or Synthetic Triglyceride

[0010] In practicing this invention, a synthetic triglyceride or a natural oil is employed of the formula

wherein R¹, R² and R³ are aliphatic hydrocarbyl groups that contain from about 7 to about 23 carbon atoms and preferably from about 11 to about 21 carbon atoms. The term "hydrocarbyl group" as used herein denotes a radical having a carbon atom directly attached to the remainder of the molecule. The aliphatic hydrocarbyl groups include the following:

(1) Aliphatic hydrocarbon groups; that is, alkyl groups such as heptyl, nonyl, undecyl, tridecyl, heptadecyl; alkenyl groups containing a single double bond such as heptenyl, nonenyl, undecenyl, tridecenyl, heptadecenyl, heneicosenyl; alkenyl groups containing 2 or 3 double bonds such as 8,11-heptadecadienyl and 8,11,14-heptadecatrienyl. All isomers of these are included, but straight chain groups are preferred.

(2) Substituted aliphatic hydrocarbon groups: that is groups containing non-hydrocarbon substituents which, in the context of this invention, do not alter the predominantly hydrocarbon character of the group. Those skilled in the art will be aware of suitable substituents: examples are hydroxy, carbalkoxy, (especially lower carbalkoxy) and alkoxy (especially lower alkoxy), the term, "lower" denoting groups containing not more than 7 carbon atoms.

(3) Hetero atom groups; that is. groups which, while having predominantly aliphatic hydrocarbon character within the context of this invention, contain atoms other than carbon present in a chain or ring otherwise composed of aliphatic carbon atoms. Suitable hetero atoms will be apparent to those skilled in the art and include, for example, oxygen, nitrogen and sulfur.

[0011] Naturally occurring oils are vegetable oil triglycerides. The synthetic triglycerides are those formed by the reaction of one mole of glycerol with three moles of a fatty acid or mixture of fatty acids. Preferred are vegetable oil triglycerides. The preferred vegetable oils are soybean oil, corn oil, lesquerella oil, rapeseed oil, sunflower oil, canola oil, coconut oil, peanut oil, safflower oil, castor oil and palm olein.

[0012] In a preferred embodiment, the aliphatic hydrocarbyl groups are such that the triglyceride has a monounsaturated character of at least 60 percent, preferably at least 70 percent and most preferably at least 80 percent. Naturally occurring triglycerides having utility in this invention are exemplified by vegetable oils that are genetically modified such that they contain a higher than normal oleic acid content. Normal sunflower oil has an oleic acid content of 25-30 percent. By genetically modifying the seeds of sunflowers, a sunflower oil can be obtained wherein the oleic content is from about 60 percent up to about 90 percent. That is, the R¹, R² and R³ groups are heptadecenyl groups and the R¹COO-, R²COO-and R³COO-to the 1,2,3-propanetriyl group -CH₂CHCH₂- are the residue of an oleic acid molecule. U.S. Patent No. 4,627,192 and 4,743,402 are herein incorporated by reference for their disclosure to the preparation of high oleic sunflower oil.

[0013] For example, a triglyceride comprised exclusively of an oleic acid moiety has an oleic acid content of 100% and consequently a monounsaturated content of 100%. Where the triglyceride is made up of acid moieties that are 70% oleic acid, 10% stearic acid, 13% palmitic acid, and 7% linoleic acid, the monounsaturated content is 70%. The preferred triglyceride oils are high oleic (at least 60 percent) acid triglyceride oils. Typical high oleic vegetable oils employed within the instant invention are high oleic safflower oil, high oleic canola oil, high oleic peanut oil, high oleic corn oil, high oleic rapeseed oil, high oleic sunflower oil, high oleic soybean oil, high oleic cottonseed oil, and high oleic palm olein. Canola oil is a variety of rapeseed oil containing less than 1 percent eruic acid. A preferred high oleic vegetable oil is high oleic sunflower oil obtained from Helianthus sp. This product is available from SVO Enterprises Eastlake, Ohio as Sunyl® high oleic sunflower oil. Sunyl 80 oil is a high oleic triglyceride wherein the acid moieties comprise 80 percent oleic acid. Another preferred high oleic vegetable oil is high oleic rapeseed oil obtained from Brassica campestris or Brassica napus, also available from SVO Enterprises as RS high oleic rapeseed oil. RS80 oil signifies a rapeseed oil wherein the acid moieties comprise 80 percent oleic acid.

[0014] It is further to be noted that genetically modified vegetable oils have high oleic acid contents at the expense of the di-and tri- unsaturated acids. A normal sunflower oil has from 20-40 percent oleic acid moieties and from 50-70 percent linoleic acid moieties. This gives a 90 percent content of mono- and di- unsaturated acid moieties (20+70) or (40+50). Genetically modifying vegetable oils generate a low di- or tri- unsaturated moiety vegetable oil. The genetically modified oils of this invention have an oleic acid moiety:linoleic acid moiety ratio of from about 2 up to about 90. A 60 percent oleic acid moiety content and 30 percent linoleic acid moiety content of a triglyceride oil gives a ratio of 2. A triglyceride oil made up of an 80 percent oleic acid moiety and 10 percent linoleic acid moiety gives a ratio of 8. A triglyceride oil made up of a 90 percent oleic acid moiety and 1 percent linoleic acid moiety gives a ratio of 90. The ratio for normal sunflower oil is 0.5 (30 percent oleic acid moiety and 60 percent linoleic acid moiety).

(B) The Random Block Copolymer

[0015] The random block copolymers of this invention comprise the product copolymerization of two monomers. The first monomer is a conjugated diene and the second monomer is a mono-vinyl aromatic. The random block copolymer formed is then hydrogenated to remove substantially all of the unsaturation.

[0016] Examples of vinyl substituted aromatics include styrene, alphamethylstyrene, ortho-methylstyrene, meta-methylstyrene, para-methylstyrene, para-tertiary-butylstyrene, with styrene being preferred. Examples of conjugated dienes include piperylene, 2,3-dimethyl-1,3-butadiene, chloroprene, isoprene and 1,3-butadiene with isoprene and 1,3-butadiene being particularly preferred. Mixtures of such conjugated dienes are useful.

[0017] The vinyl substituted aromatic monomer content of these random block copolymers is in the range of from about 20 percent to about 70 percent by weight and preferably from about 40 percent to about 60 percent by weight. Thus, the aliphatic conjugated diene monomer content of these copolymers is in the range of from about 30 percent to about 80 percent by weight and preferably from about 40 percent to about 60 percent by weight.

[0018] What follows is a discussion on the different types of random block copolymers.

[0019] In general, it is preferred that these block copolymers, for reasons of oxidative stability, contain no more than about 5 percent and preferably no more than about 0.5 percent residual olefinic unsaturation on the basis of the total number of carbon-to-carbon covalent linkages within the average molecule. Such unsaturation can be measured by a number of means well known to those of skill in the art, such as infrared, NMR, etc. Most preferably, these copolymers contain no discernible unsaturation as determined by the aforementioned analytical techniques.

[0020] The random block copolymers of this invention typically have a number average molecular weight in the range of about 5,000 to about 1,000,000; preferably about 30,000 to about 300,000. The weight average molecular weight for these copolymers is generally in the range of about 50,000 to about 500,000; preferably about 30,000 to about 300,000.

I. Random Copolymers: Those in which the comonomers are randomly, or nearly randomly, arranged in the polymer chain, with no significant degree of blocking homopolymer segments of either monomer. The general polymer structure of a random copolymer can be represented by:

wherein S denotes a vinyl aromatic monomer such as styrene, and D denotes a conjugated diene monomer such as 1,3-butadiene or isoprene. Such random copolymers, may easily be made by free radical copolymerization.
While the diene monomer introduces an olefinic unsaturation of some sort, either in the main backbone of the polymer, or pendant on it, it is to be understood that the olefinic sites may be substantially removed by hydrogenation.

II. Regular Linear Block Copolymers: Those in which a small number of relatively long chains of homopolymer of one type of monomer are alternately jointed to a small number of relatively long chains of homopolymer of another type of monomer. Normal, or regular, block copolymers usually have from 1 to about 3, preferably only from 1 to 2 relatively large homopolymer blocks of each monomer. Thus, a linear regular diblock copolymer of styrene or other vinyl aromatic monomer S and conjugated diene D would have a general structure represented by a large block of homopolymer S attached to a large block of homopolymer D:

The blocks of monomer S and monomer D are not necessarily of the same size or molecular weight. As before, it is understood that the initial olefinic unsaturation introduced into the copolymer by diene monomer D has been substantially removed by hydrogenation. Linear diblock copolymers comprising hydrogenated poly-(styrene-b-isoprene) are sold under the trade names "Shellvis 40, 50 and 90" by Shell Chemical Company.
In like manner, regular triblock copolymers are understood as having three relatively large major blocks, or segments of homopolymer composed of either two monomers; i.e., as in:

and,

A third monomer A may also be incorporated in these linear, regular block copolymers. In this instance, several configurations are possible, depending on how the homopolymer segments are incorporated with respect to each other. For example, a linear triblock copolymer of monomers S, D and A could be represented by several different configurations:

or,

III. Linear Random Block Copolymers: Those in which a relatively large number of relatively short segments of homopolymer of one type of monomer alternate with a relatively large number of short segments of homopolymer of another monomer type.
Random block polymers of this invention may be linear, or they may be partially, or highly branched. The relative arrangement of homopolymer segments in a linear random block polymer, which is the most preferred block polymer of this invention, may be represented by:

wherein D represents a conjugated diene monomer, and A represents a vinyl aromatic monomer. The arrangement of the individual homopolymer segments of each type of monomer in a linear random block polymer is alternating.

IV. Linear Tapered Random Block Copolymers:
A special type of configuration in linear random block copolymers is the linear tapered random block structure. In this arrangement, a major portion of the polymer backbone is of the random block type, with larger blocks of one type of homopolymer situated at one end of the molecule. The synthesis of this type of polymer is usually carried out by preparing a linear random block copolymer, then adding more of one of the monomer types near the end of the polymerization, so that the additional polymer forms a series of ever larger homopolymer blocks at the end of the growing linear polymer chain. The vinyl substituted aromatic monomer is generally chosen to provide the larger, tapered homopolymer blocks, although other types of monomers may be used for this purpose.

[0021] Linear tapered random block copolymers may have significantly different solubilities in diluents normally used in lubricant formulations, as well as superior thickening power at high temperature, better high temperature viscosity under conditions of high shear, and improved low temperature viscometrics, compared to simple random block copolymers of similar molecular weight, made from the same monomers.

[0022] The styrene/diene block polymers considered in this invention are usually made by anionic polymerization, using a variety of techniques, and altering reaction conditions to produce the most desirable microstructural features in the resulting polymer.

[0023] In an anionic polymerization, the initiator may be either an organometallic such as an alkyl lithium, or the anion formed by electron transfer from a Group IA metal to an aromatic such as naphthalene. The most efficacious organometallic is usually an alkyl lithium such as sec-butyl lithium, and the polymerization is initiated by butyl anion addition to either the diene monomer, or to styrene. With sec-butyl lithium initiator, propagation occurs in only one direction, and the growing polymer is anionically charged on one end, the negative charge being associated with a positively-charged lithium gegenion.

[0024] Using an alkyl lithium initiator, a homopolymer of one monomer, e.g., styrene, may be grown selectively, with each polymer molecule having an anionic terminus, and lithium gegenion:

Since all the anionic sites are presumed to have equal reactivity toward monomer molecules, polymer growth at each site is essentially the same, and the resulting polymers will, when monomer is completely depleted, all be of similar molecular weight and composition. Thus, polymers made by anionic polymerization are said to be nearly "monodisperse"; i.e., the ratio of weight average molecular weight to number average molecular weight is very nearly 1.0. In practice, the polydispersity factor for properly synthesized styrene-diene anionic block polymers is usually about 1.05- 1.10.

[0025] As long as nothing is introduced into the polymerization mixture that would act to terminate the activity of the growing anionic end of a styrene homopolymer segment, the composition constitutes a "living" polymer that maintains its activity, and can grow further by interaction with monomers that are also capable of anionic polymerization. These monomers may be additional styrene or similar vinyl aromatic monomers, or they may comprise a different chemical type, such as 1,3-dienes (e.g., 1,3-butadiene or isoprene). Addition of 1,3-butadiene or isoprene to the homopolystyrene-lithium living polymer produces a second segment which grows from the anion site to produce a living di-block polymer having an anionic terminus, with lithium gegenion.

[0026] Again, the size of this "D" block, i.e., the degree of polymerization ("DP"), will be determined principally by the amount of diene monomer added, and the number of active anionic sites available. As in the case of the first (polystyrene) segment, the molecular weight of the new (polydiene ) segments will all be about the same, and the polydispersity factor of the new poly S-block-poly-D living polymer will remain about 1.0. Similarly, the terminus of the new S-D diblock polymer will be anionic with a lithium gegenion, and the diblock will be "living" in the sense that the anionic site will remain active toward further polymerization when exposed to additional anionically-polymerizable monomers. Introduction of additional styrene could produce a new poly S-block-poly D-block-poly S, or S-D-S triblock polymer; higher orders of block polymers could theoretically be made by consecutive stepwise additions of different monomers in different sequences.

[0027] A common practice in manufacture of S-D-S type triblock polymers is to couple a living diblock polymer by exposure to an agent such as dialkyldichlorosilane. When the carbanionic "heads" of two S-D diblock living polymers are coupled using such an agent, precipitation of LiCl occurs to give an S-D-S tri

lock po

ymer of somewhat different^-structure than that o

tained by the sequential monomer addition method described above, wherein the size of the central D block is double that of the D block in the starting living (anionic) diblock intermediate:

[0028] The polymerization to form block polymers may also be approached in a slightly different manner. In cases where metal naphthalide is used to initiate polymerization, single electron-transfer to monomer (S) generates a radical-anion which may dimerize to yield a di-anionic nuceophile which is capable of initiating polymerization in two directions simultaneously. Thus,





The polyS segment is a living dianionic species that can continue to initiate polymerization in two directions. Exposure to a second monomer (D) results in formation of a polyD-block-PolyS-block-PolyD, or a D-S-D triblock polymeric dianion.:

Again, the dianion is living, in the sense that it may continue to interact with additional anionically-polymerizable monomers of the same, or different chemical type, in the formation of higher order block polymers.

[0029] The effect of solvents in anionic polymerization is considerable, and can determine in large measure the nature of the copolymer that is ultimately formed. Polymerization is frequently carried out in what is considered to be a non-polar solvent such as hexane, heptane or an aromatic such as benzene or toluene. Non-polar paraffinic solvents tend to inhibit charge separation at the growing anion, and diminish the basicity of the active organolithium head. These paraffinic solvents also tend to slow down the rates of initiation and emphasize the differences in relative rate of polymerization between various anionically-polymerizable monomers. Thus, when two different monomer types are available, the one which initiates faster takes precedence.

[0030] Usually, the same monomer will also polymerize faster, building a segment that is richer in that monomer, and contaminated by occasional incorporation of the other monomer. In some cases, this can be used beneficially to build a type of polymer referred to as a "random block polymer", or "tapered block polymer". When a mixture of two different monomers is anionically polymerized in a non-polar paraffinic solvent, one will initiate selectively, and usually polymerize to produce a relatively short segment of homopolymer. Incorporation of the second monomer is inevitable, and this produces a short segment of different structure. Incorporation of the first monomer type then produces another short segment of that homopolymer, and the process continues. to give a more or less "random" alternating distribution of relatively short segments of homopolymers, of different lengths. At some point, one monomer will be considerably depleted over the other, favoring incorporation of the first, more or less on the basis of the principle of mass action. The result of enrichment of one monomer over the other in the latter stages of polymerization produces even longer blocks of homopolymer derived from the monomer in higher concentration. The result is a "tapered block copolymer", having a multitude of shorter homopolymer segments, usually diads (2 monomers) to pentads (5-monomers), and a "tail" enriched in longer segments of the less reactive monomer.

[0031] An alternative way of preparing random or tapered block copolymers involves initiation of styrene, and interrupting with periodic, or step, additions of diene monomer. The additions are programmed according to the relative reactivity ratios and rate constants of the styrene and particular diene monomer.

[0032] "Promoters" are electron-rich molecules that tend to enhance the basic nature of the organolithium active site by coordinating with the positively-charged lithium cation, polarizing the charged species to effect greater charge separation at the active site where interaction with virgin monomer occurs. Promoters include tetrahydrofuran, tetrahydropyran, linear and crown ethers, N,N-dimethylformamide, tetramethyl ethylenediamine, and other non-protic agents that have non-bonding electron pairs available for coordination. Promoters tend to facilitate anionic initiation and polymerization rates in general. while lessening the relative differences in rates between various monomers. Promoters may be added in small amounts to polymerization mixtures containing mixed monomers in non-polar paraffinic or aromatic solvents in order to speed the reaction, and to effect the nature of the size and distribution of blocks in the final copolymer.

[0033] Promoters also influence the way in which diene monomers are incorporated into the block polymer. A diene monomer can polymerize by 1,2- or 1,4-addition (see following reaction scheme), and the 1,4-addition can (theoretically) be either in a trans- or cis- configuration. Studies using 1,3-butadiene/styrene monomers with sec-butyl lithium initiator, have shown that in non-polar paraffinic solvents, the diene monomer incorporates predominantly (86-95%) by cis-1,4-addition. Addition of small amounts of tetrahydrofuran promoter cause 1,3-butadiene to increasingly favor 1,2-polymerization over the normal 1,4-cis-polymerization.

[0034] Hydrogenation of the unsaturated block polymers obtained initially as polymerization products produces polymers that are more oxidatively and thermally stable. Reduction is typically carried out at part of the polymerization process, using finely divided, or supported, nickel catalyst. Other transition metals may also be used to effect transformation. Hydrogenation is normally carried out to the extent of reducing approximately 94-96% of the olefinic unsaturation in the initial polymer. This means that the manner in which the diene monomer incorporates becomes an important parameter affecting the final physical and solution properties of the hydrogenated polymers at ambient and low temperatures. The figure below shows diene incorporated both in a 1,4-cis and 1,2-manner. Hydrogenation of a 1,4-cis configuration produces linear polyethylene segments in the polymer, reducing solubility in general, and introducing highly crystalline sites that tend to associate at low temperatures, and introduce potentially undesirable melt-associated thermal transitions.

In contrast, hydrogenation of diene introduced by 1,2-polymerization results in a pendant alkyl group that enhances solubility, decreases crystallinity in the diene segments, and substantially reduces the tendency toward association. The ability to control the balance of 1,4- and 1,2-modes of diene monomer incorporation, in order to optimize overall properties of the hydrogenated block polymer, for use as a viscosity modifier in lubricating oil compositions.

[0035] Isoprene incorporates into block polymers in a similar manner to that of 1,3-butadiene, i.e., either by 1,4-cis or 3,4-polymerization. As with 1,3-butadiene, predominantly cis-1,4-incorporation is usual in non-polar paraffinic solvents, but promoters, such as tetrahydrofuran, favor 3,4-polymerization. Again, a balance of properties may be achieved by using small amounts of electron-rich promoters to speed initiation and polymerization, and to influence the nature and properties of the final, hydrogenated polymer. With isoprene, there will be no possibility of formation of crystalline polyethylene segments on the hydrogenation, because there will always be aliphatic substituents in the polyisoprene blocks.

[0036] It can be seen, then that the physical and solution properties of block copolymers are dependent on both the monomers used, and the method of preparation. The morphological characteristics of polymer solutions are similarly dependent on polymer microstructure. Morphology refers to the actual conformation of polymers under a defined set of conditions, and is dependent on structure, polymer concentration, temperature, and additional influences of solvents and other agents. Many types of block polymers show a good deal of intermolecular associative behavior, wherein blocks, or segments, of like homopolymer may agglomerate. In this sense, the block polymers demonstrate a kind of surface-active nature,wherein they form micelles, similar to those formed by classical surfactants. Supporting this property are studies which have shown that block polymers have the ability to stabilize colloidal dispersions. An example of surfactant properties can be shown by the ability of polystyrene-block copolymers to stabilize dimethylformamide-hexane emulsions.

[0037] Associative polymers can agglomerate in several ways, to produce discreetly different structures, depending on the nature and arrangement of their blocks. Morphological structures range from spherical and core-shell, to cylindrical and lamellar. In a spherical or core-shell association, the center of the sphere is usually formed by the more highly associative or crystalline segments, surrounded by a (usually more diffuse) mantle or shell which is enriched in the second type of segment, which is frequently swollen by solvent or diluent. The cylindrical form is similar to a spherical form, except that the core extends from one end to the other, in an elongated shape, rather than a sphere. The lamellar form comprises an arrangement of parallel planes of associated blocks, alternating by type of segment. The morphology of copolymers having highly crystalline segments are usually controlled by the temperature at which such crystallization occurs, since this effectively "freezes" the entire structure. Thus, segments having significant crystallinity can effectively impose their morphology on the remainder of the copolymer.

[0038] Intermolecular association of oil-soluble block copolymers used as viscosity modifiers for lubricants can pose significant problems, in terms of handleability of concentrates. The polymer content of a polymeric viscosity improver concentrate ranges typically from about 540% by weight, in a mineral oil, synthetic hydrocarbon, or ester diluent. With non-associative polymers, such as OCP, EPDM, butyl polymer or polymethacrylates, concentrates can be prepared at relatively high polymer concentrations, without experiencing unduly highly bulk viscosities. The styrene-diene block copolymers, however, are highly associative through the mutual affinity of their polystyrene segments, so that the amount of polymer that can be dissolved before the concentrate viscosity become too great to pour, is relatively low. The association problem is exacerbated by the use of non-polar mineral oils or synthetic hydrocarbon diluents that are relatively poor solvents for the polystyrene segments in the block copolymers. In these diluents, the degree of association is relatively high, and the combined effective molecular weight of the aggregates, astronomical. The effective thickening power of the copolymer aggregates renders the concentrate a gel, and the concentrate becomes unpourable at temperatures as high as 100°C.

[0039] In general, polystyrene-block-polyisoprene hydrogenated diblock copolymers have two relatively large segments associated to a much greater degree than do random block polymers of similar composition and molecular weight that have a much larger number of relatively short polystyrene segments. Typically, the diblock copolymer concentrate can contain no more than about 6% by weight, and the random block copolymer no more than about 8% to be pourable at 100°C.

[0040] In general, it is preferred that these block copolymers, for reasons of oxidative stability, contain no more than about 5 percent and preferably no more than about 0.5 percent residual olefinic unsaturation on the basis of the total number of carbon-to-carbon covalent linkages within the average molecule. Such unsaturation can be measured by a number of means well known to those of skill in the art, such as infrared NMR, etc. Most preferably, these copolymers contain no discernible unsaturation as determined by the aforementioned analytical techniques.

[0041] Examples of commercially available random block copolymers include the varioius Glissoviscal block copolymers manufactured by BASF. Two especially preferred copolymers are Glissoviscal® SGH and Glissoviscal® CE-5260.

[0042] In addition to components (A) and (B), the compositions of this invention may also contain (C) at least one oxidation inhibitor, (D) at least one extreme pressure/anti-wear additive or mixtures thereof.

(C) The Oxidation Inhibitor

[0043] The oxidation inhibitor comprises

(1) an alkyl phenol,

(2) an aromatic amine, or

(3) a heterocyclic amine.

(C1) The Alkyl Phenol

[0044] Component (C)(1) is an alkyl phenol of the formula

wherein R⁴ is an alkyl group containing from 1 up to about 24 carbon atoms, a is an integer of from 1 up to 3 and z is 1 or 2. Preferably R⁴ contains from 1 to 12 carbon atoms and most preferably from 4 to 12 carbon atoms. R⁴ may be either straight chained or branched chained and branched chain is preferred. The preferred value for a is 2 and the preferred value for z is 1.

[0045] Mixtures of alkyl phenols may be employed. Preferably the phenol is a butyl substituted phenol containing two t-butyl groups. When a is 2, the t-butyl groups occupy the 2,6-position, that is the phenol is sterically hindered:

When a is 3, the t-butyl groups occupy the 2,4,6- positions.

(C2) The Aromatic Amine

[0046] Component (C)(2) is an aromatic amine of the formula

wherein b is 1 or 2 and when b is 1, R⁵ is

and R⁶ and R⁷ are independently a hydrogen or an alkyl group containing from 1 up to about 24 carbon atoms, and when b is 2, R⁵ and R⁶ are independently hydrogen, an aryl group or an alkyl group containing from 1 up to about 18 carbon atoms. Preferably b is 1, R⁵ is

and R⁶ and R⁷ are both nonyl groups. When b is 2, R⁵ preferably is

and R⁶ and R⁷ are both hydrogen.

(C3) The Heterocyclic Amine

[0047] Component (C3) is a heterocyclic amine of formulae (a) or (b)

wherein R⁸ is independently a hydrogen or an alkyl group containing from 1 up to about 4 carbon atoms, Z is hydrogen or → O· and X is hydrogen, -NR¹⁴R¹⁵ or -OR¹⁵ wherein R¹⁴ and R¹⁵ are independently hydrogen or alkyl groups containing from 1 up to about 18 carbon atoms.

[0048] Within formula (C3a) and (C3b) R⁸ is preferably methyl. Compounds having utility in this invention within formula (C3a) are 2,2,6,6-tetramethylpiperidine where X and Z are both hydrogen; 2,2,6,6-tetramethyl-1-piperidinol where X is -OR¹⁵ and R¹⁵ and Z are both hydrogen; and 2,2,6,6-tetramethyl-1-piperidinyloxy free radical where Z is → O· and X is hydrogen. A compound having utility in this invention within formula (C3b) is 2,2,6,6-tetramethyl-4-piperidone where Z is hydrogen.

(D) The Extreme Pressure/Antiwear Additive

[0049] The extreme pressure/antiwear additive comprises

(1) a metal sulfur/phosphorus salt,

(2) a metal sulfur/nitrogen salt,

(3) a benzotriazole,

(4) a sulfurized composition, and

(5) a derivative of a dimercaptothiadiazole.

(D1) The Metal Sulfur/Phosphorus Salt

[0050] Component (D1) is a metal sulfur/phosphorus salt of the formula

wherein R⁹ and R¹⁰ are independently hydrocarbyl groups containing from 3 up to about 20 carbon atoms, M¹ is a metal selected from the group consisting of lithium, sodium, calcium, barium, copper, zinc, antimony, tin, cerium and other members of the lanthanide series, and x is the valence of M¹.

[0051] Component (D1) is readily obtainable by the reaction of phosphorus pentasulfide (P₂S₅) and an alcohol or phenol. The reaction involves mixing at a temperature of about 20°C to about 200°C. four moles of an alcohol or phenol with one mole of phosphorus pentasulfide. Hydrogen sulfide is liberated in this reaction.

[0052] The R⁹ and R¹⁰ groups are independently hydrocarbyl groups that are preferably free from acetylenic and usually also from ethylenic unsaturation and have from 3 to about 20 carbon atoms, preferably 3 to about 16 carbon atoms and most preferably 3 to about 12 carbon atoms.

[0053] Preferred metals acting as M¹ are copper, zinc, tin and cerium.

[0054] The following examples outline how component (D1) is prepared.

Example (D1)-1

[0055] A reaction vessel is charged with 804 parts of a mixture of 6.5 moles of isobutyl alcohol and 3.5 moles of mixed primary amyl alcohols (65% w n-amyl and 35% w 2-methyl-1-butanol). Phosphorus pentasulfide (555 parts, 2.5 moles) is added to the vessel while maintaining the reaction temperature between about 104°-107°C. After all of the phosphorus pentasulfide is added, the mixture is heated for an additional period to insure completion of the reaction and filtered. The filtrate is the desired phosphorodithioic acid which contains about 11.2% phosphorus and 22.0% sulfur.

[0056] A reaction vessel is charged with 448 parts of zinc oxide (11 equivalents) and 467 parts of the above alcohol mixture. The above phosphorodithioic acid (3030 parts, 10.5 equivalents) is added at a rate to maintain the reaction temperature at about 45°-50°C. The addition is completed in 3.5 hours whereupon the temperature of the mixture is raised to 75°C for 45 minutes. After cooling to about 50°C, an additional 61 parts of zinc oxide (1.5 equivalents) are added, and this mixture is heated to 75°C for 2.5 hours. After cooling to ambient temperature, the mixture is stripped to 124°C at mm. pressure. The residue is filtered twice through diatomaceous earth, and the filtrate is the desired zinc salt containing 22.2% sulfur (theory, 22.0), 10.4% phosphorus (theory, 10.6) and 10.6% zinc (theory, 11.1).

Example (D1)-2

[0057] The procedure of Example (D1)-1 is essentially followed except that 2-methylpentyl alcohol is used in place of the isobutyl alcohol and amyl alcohols. The product obtained has 8.5% phosphorus, 17.6% sulfur and 9.25% zinc.

(D2) The Metal Sulfur/Nitrogen Salt

[0058] Component (D2) is a metal sulfur/nitrogen salt of the formula

wherein R¹¹ and R¹² are independently hydrocarbyl groups containing from 1 up to about 24 carbon atoms, M² is a metal moiety selected from the group consisting of copper, zinc, antimony, tin, cerium and other members of the lanthanide series and a molybdenum cation selected from the group consisting of -Mo=O and

and y is the valence of M².

[0059] Preferably R¹¹ and R¹² are aliphatic groups containing from 3 up to about 12 carbon atoms and M² is preferably copper, antimony or zinc.

[0060] An example of a metal sulfur/nitrogen salt is an antimony dialkyldithiocarbamate obtained from the R.T. Vanderbilt Company and known as Vanlube 73. From laboratory analysis Vanlube 73 is believed to consist of antimony dipentyldithiocarbamate.

(D3) The Benzotriazole

[0061] Component (D3) is a benzotriazole of the formula

wherein R¹³ is hydrogen or an alkyl group containing from 1 up to about 12 carbon atoms, R¹⁶ is hydrogen or -CH₂SR¹⁷ where R¹⁷ is an alkyl group containing from 1 up to about 18 carbon atoms.

[0062] Preferably R¹³ is a methyl group and R¹⁶ is hydrogen which results in (D3) being tolyltriazole of the formula

Tolyltriazole is available under the trade name Cobratec TT-100 from Sherwin-Williams Chemical.

(D4) The Sulfurized Composition

[0063] Within the purview of this invention, three different sulfurized compositions (D4a), (D4b) and (D4c) are envisaged and have utility. The first sulfurized composition (D4a), is a sulfurized olefinic hydrocarbon prepared in essentially a two-step process that involves: 1) reacting an olefin with a sulfur halide to form a sulfochlorinated adduct, and 2) contacting the sulfochlorinated adduct with sodium sulfide or sodium polysulfide in a protic solvent. The protic solvent may be water and an alcohol of 4 carbon atoms or less. Preferably, the alcohol is isopropyl alcohol. The sodium polysulfide solution is best prepared by dissolving sulfur into an aqueouss Na₂S or NaSH/Na₂S solution. Water and aqueous NaOH are added as necessary to adjust the basic sulfide concentration to a range of 18-21 percent Na₂S and 2-5 percent NaOH.

[0064] Additions of sulfur dichloride (SCl₂) or sulfur monochloride (S₂Cl₂) to an olefin produces sulfochloride intermediates having sulfide and disulfide groups in the adducts. Contact of the sulfochloride intermediates withi the sodium sulfide or sodium polysulfide solutions described results in nucleophilic displacement of active chlorine as sodium chloride, and produces additional sulfide or polysulfide groups within the product molecule. The product is a substantially chlorine-free sulfurized compound that can be used as a lubricant additive.

[0065] A wide variety of olefins may be charged to the initial sulfochlorination reaction including hydrocarbon olefins having a single double bond with terminal or internal double bonds and containing from about 2 to 50 or more, preferably 2 to 8 carbon atoms per molecule in either straight, branched chain or cyclic compounds, and these may be exemplified by ethylene, propylene, butene-1, cis-and trans- butene-2, isobutylene, diisobutylene, triisobutylene, pentenes, cyclopentene, cyclohexene, the octenes, decene-1, etc. In general C_3-6 olefins or mixtures thereof are desirable for preparing sulfurized products for use as extreme pressure additives. The combined sulfur content of the product decreases with increasing olefin carbon number, while miscibility with oil increases.

[0066] 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 1:(1-20). 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 S₂Cl₂ (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.

[0067] After the sulfurization-dechlorination reaction, the reaction mixture is allowed to stand and separate into an aqueous layer and another liquid layer containing the desired organic sulfide product. The product is usually dried by heating at moderately elevated temperatures under subatmospheric pressure, and its clarity may often be improved by filtering the dried product through a bed of bauxite, clay or diatomaceous earth particles.

[0068] The following example is provided so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make the first sulfurized composition.

Example (D4a)-1

[0069] Added to a three-liter, four-necked flask are 1100 grams (8.15 moles) of sulfur monochloride. While stirring at room temperature 952 grams (17 moles) of isobutylene are added below the surface. The reaction is exothermic and the addition rate of isobutylene controls the reaction temperature. The temperature is allowed to reach a maximum of 50°C and obtained is a sulfochlorination reaction product.

[0070] A blend of 1800 grams of 18% Na₂S solution is obtained from process streams. To this blend is added 238 grams 50% aqueous NaOH, 525 grams water and 415 grams isopropyl alcohol to prepare a reagent for use in the sulfurization-dechlorination reaction. To this reagent is added 1000 grams of the sulfochlorination reaction product in about 1.5 hours. One hour after the addition is completed, the contents are permitted to settle and the liquid layer is drawn off and discarded. The organic layer is stripped to 120°C and 100 mm Hg to remove any volatiles. Analyses: % sulfur 43.5, % chlorine 0.2.

[0071] Table I outlines other olefins and sulfur chlorides that can be utilized in preparing the first sulfurized composition. The procedure is essentially the same as in Example (D4a)-1. In all the examples, the metal ion reagent is prepared according to Example (D4a)-1.

[0072] 

Table I

Example	Olefin	Sulfur Chloride	Mole Ratio of Olefin:SC1
(D4a)-2	n-butene	SCl2	2.3:1
(D4a)-3	propene	S2Cl2	2.5:1
(D4a)-4	n-pentene	S2Cl2	2.2:1
(D4a)-5	n-butene/isobutylene 1:1 weight	S2Cl2	2.5:1
(D4a)-6	isobutylene/2-pentene 1:1 weight	S2Cl2	2.2:1
(D4a)-7	isobutylene/2-pentene 3:2 weight	S2Cl2	2.2:1
(D4a)-8	isobutylene/propene 6:1 weight	S2Cl2	2.3:1
(D4a)-9	n-pentene/2-pentene 1:1 weight	S2Cl2	2.2:1
(D4a)-10	2-pentene/propene 3:2 weight	S2Cl2	2.2:1

[0073] The second sulfurized composition (D4b), is also a sulfurized olefinic hydrocarbon that comprises the reaction product of sulfur and a Diels-Alder adduct. The Diels-Alder adducts are a well known, art-recognized class of compounds prepared by the diene synthesis or Diels-Alder reaction. A summary of the prior art relating to this class of compounds is found in the Russian monograph, Dienovyi Sintes, Izdatelstwo Akademii Nauk SSSR, 1963 by A.S. Onischenko. (Translated into the English language by L. Mandel as A.S. Onischenko, Diene Synthesis, N.Y., Daniel Davey and Co., Inc., 1964). This monograph and references cited therein are incorporated by reference into the present specification.

[0074] Basically, the diene synthesis (Diels-Alder reaction) involves the reaction of at least one conjugated diene, >C=C-C=C<, with at least one ethylenically or acetylenically unsaturated compound, >C=C<, these latter compounds being known as dienophiles. The reaction can be represented as follows:

[0075] 

[0076] 

[0077] The products, A and B are commonly referred to as Diels-Alder adducts. It is these adducts which are used as starting materials for the preparation of the second sulfurized composition.

[0078] Representative examples of such 1,3-dienes include aliphatic conjugated diolefins or dienes of the formula

wherein R¹⁸ through R²³ are each independently selected from the group consisting of halogen, alkyl, halo, alkoxy, alkenyl. alkenyloxy, carboxy, cyano, amino, alkylamino, dialkylarnino, phenyl, and phenyl-substituted with 1 to 3 substituents corresponding to R¹⁸ through R²³ with the proviso that a pair of R's on adjacent carbons do not form an additional double bond in the diene. Preferably not more than three of the R variables are other than hydrogen and at least one is hydrogen. Normally the total carbon content of the diene will not exceed 20. In one preferred aspect of the invention, adducts are used where R²⁰ and R²¹ are both hydrogen and at least one of the remaining R variables is also hydrogen. Preferably, the carbon content of these R variables when other than hydrogen is 7 or less. In this most preferred class, those dienes where R¹⁸, R¹⁹, R²² and R²³ are hydrogen, chloro, or lower alkyl are especially useful. Specific examples of the R variables include the following groups: methyl, ethyl, phenyl, HOOC-, N≡C-, CH₃COO-, CH₃CH₂O-, CH₃C(O)-, HC(O), -C1, -Br, tert-butyl, CF₃, tolyl, etc. Piperylene, isoprene, methylisoprene, chloroprene, and 1,3-butadiene are among the preferred dienes for use in preparing the Diels-Alder adducts.

[0079] The dienophiles suitable for reacting with the above dienes to form the adducts used as reactants can be represented by the formula

wherein the K variables are the same as the R variables in the diene formula above.

[0080] A preferred class of dienophiles are those wherein at least one of the K variables is selected from the class of electron-accepting groups such as formyl, cyano, nitro, carboxy, carbohydrocarbyloxy, hydrocarbylcarbonyl, hydrocarbylsulfonyl, carbamyl, acylacarbanyl, N-acyl-N-hydrocarbylcarbamyl, N-hydrocarbylcarbamyl, and N,N-dihydrocarbylcarbamyl. Those K variables which are not electron-accepting groups are hydrogen, hydrocarbyl, or substituted-hydrocarbyl groups. Usually the hydrocarbyl and substituted hydrocarbyl groups will not contain more than 10 atoms each.

[0081] The hydrocarbyl groups present as N-hydrocarbyl substituents are preferably alkyl of 1 to 30 carbon atoms and especially 1 to 10 carbon atoms. Representative of this class of dienophiles are the following: maleic anhydride, nitroalkenes, e.g., 1-nitrobutene-1, 1-nitropentene-1, 3-methyl-1-nitro-butene-1, 1-nitroheptene-1, 1-nitrooctene-1, 4-ethoxy-1-nitrobutene-1; alpha, beta-ethylenically unsaturated aliphatic carboxylic acid esters, e.g., alkylacrylates and alpha-methyl alkylacrylates (i.e., alkyl methacrylates) such as butylacrylate and butylmethacrylate, decyl acrylate and decylmethacrylate, di-(n-butyl)-maleate, di-(t-butyl-maleate); acrylonitrile, methacrylonitrile, beta-nitrostyrene, methylvinyl-sulfone, acrolein, acrylic acid; alpha, beta-ethylenically unsaturated aliphatic carboxylic acid amides, e.g., acrylamide, N,N-dibutylacrylamide, methacrylamide, N-dodecylmethacrylamide, N-penyl-crotonamide; crotonaldehyde, crotonic acid, beta, beta-dimethyldivinylketone, methyl-vinyl-ketone, N-vinyl pyrrolidone, alkenyl halides, and the like.

[0082] One preferred class of dienophiles are those wherein at least one, but not more than two of K variables is -C(O)O-R° where R° is the residue of a saturated aliphatic alcohol of up to about 40 carbon atoms; e.g., for example at least one K is carbohydrocarbyloxy such as carboethoxy, carbobutoxy, etc., the aliphatic alcohol from which -R° is derived can be a mono- or polyhydric alcohol such as alkyleneglycols, alkanols, aminoalkanols, alkoxy-substituted alkanols, ethanol, ethoxy ethanol, propanol, beta-diethylaminoethanol, dodecyl alcohol, diethylene glycol, tripropylene glycol, tetrabutylene glycol, hexanol, octanol, isooctyl alcohol, and the like. In this especially preferred class of dienophiles, not more than two K variables will be -C(O)-O-R° groups and the remaining K variables will be hydrogen or lower alkyl, e.g.. methyl. ethyl, propyl, isopropyl, and the like.

[0083] Specific examples of dienophiles of the type discussed above are those wherein at least one of the K variables is one of the following groups: hydrogen, methyl, ethyl, phenyl, HOOC-, HC(O)-. CH₂=CH-, HC≡C-, CH₃C(O)-, C1CH₂-, HOCH₂-, alpha-pyridyl, -NO₂, -C1, -Br, propyl, iso-butyl, etc.

[0084] In addition to the ethylenically unsaturated dienophiles, there are many useful acetylenically unsaturated dienophiles such as propiolaldehyde, methylethynylketone, propylethynylketone, propenylethynylketone, propiolic acid, propiolic acid nitrile, ethylpropiolate, tetrolic acid, propargylaldehyde, acetylenedicarboxylic acid, the dimethyl ester of acetylenedicarboxylic acid, dibenzoylacetylene, and the like.

[0085] The second sulfurized compositions are readily prepared by heating a mixture of sulfur and at least one of the Diels-Alder adducts of the types discussed hereinabove at a temperature within the range of from about 100°C to about 200°C will normally be used. This reaction results in a mixture of products, some of which have been identified. In the compounds of know structure, the sulfur reacts with the substituted unsaturated cycloaliphatic reactants at a double bond in the nucleus of the unsaturated reactant.

[0086] The molar ratio of sulfur to Diels-Alder adduct used in the preparation of this sulfur-containing composition is from about 1:2 up to about 4:1. Generally, the molar ratio of sulfur to Diels-Alder adduct will be from about 1:1 to about 4:1 and preferably about 2:1 to about 4:1.

[0087] The reaction can be conducted in the presence of suitable inert organic solvents such as mineral oils, alkanes of 7 to 18 carbons, etc., although no solvent is generally necessary. After completion of the reaction, the reaction mass can be filtered and/or subjected to other conventional purification techniques. There is no need to separate the various sulfur-containing products as they can be employed in the form of a reaction mixture comprising the compounds of known and unknown structure.

[0088] As hydrogen sulfide is an undesirable contaminant, it is advantageous to employ standard procedures for assisting in the removal of the H₂S from the products. Blowing with steam, alcohols, air, or nitrogen gas assists in the removal of H₂S as does heating at reduced pressures with or without the blowing.

[0089] It is sometimes advantageous to incorporate materials useful as sulfurization catalysts in the reaction mixture. These materials may be acidic, basic or neutral. Useful neutral and acidic materials include acidified clays such as "Super Filtrol", p-toluenesulfonic acid, dialkylphosphoro-dithioic acids, phosphorus sulfides such as phosphorus pentasulfide and phosphites such as triaryl phosphites (e.g., triphenyl phosphite).

[0090] The basic materials may be inorganic oxides and salts such as sodium hydroxide, calcium oxide and sodium sulfide. The most desirable basic catalysts, however, are nitrogen bases including ammonia and amines. The amines include primary, secondary and tertiary hydrocarbyl amines wherein the hydrocarbyl radicals are alkyl, aryl, aralkyl, alkaryl or the like and contain about 1-20 carbon atoms. Suitable amines include aniline, benzylamine, dibenzylamine, dodecylamine, naphthylamine, tallow amines, N-ethyl-dipropylamine, N-phenylbenzylamine, N,N-diethylbutylamine, m-toluidine and 2,3-xylidine. Also useful are heterocyclic amines such as prrolidine, N-methylpyrrolidine, piperidine, pyridine and quinoline.

[0091] The preferred basic catalysts include ammonia and primary, secondary or tertiary alkylamines having about 1-8 carbon atoms in the alkyl radicals. Representing amines of this type are methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, di-n-butylanine, tri-n-butylamine, tri-sec-hexylamine and tri-n-octylamine. Mixtures of these amines can be used, as well as mixtures of ammonia and amines.

[0092] When a catalyst is used, the amount is generally about 0.05-2.0% of the weight of the adduct.

[0093] The following example illustrates the preparation of the second sulfurized composition. Unless otherwise indicated in these examples and in other parts of this specification, as well as in the appended claims, all parts and percentages are by weight.

Example (D4b)-1

[0094] A mixture comprising 400 parts of toluene and 66.7 parts of aluminum chloride is charged to a two-liter flask fitted with a stirrer, nitrogen inlet tube, and a solid carbon dioxide-cooled reflux condenser. A second mixture comprising 640 parts (5 moles) of butyl acrylate and 240.8 parts of toluene is added to the AlCl₃ slurry while maintaining the temperature within the range of 37-58°C over a 0.25-hour period. Thereafter, 270 parts (5 moles) of butadiene is added to the slurry over a 2.75-hour period while maintaining the temperature of the reaction mass at 50-61°C by means of external cooling. The reaction mass is blown with nitrogen for about 0.33 hour and then transferred to a four-liter separatory funnel and washed with a solution of 150 parts of concentrated hydrochloric acid in 1100 parts of water. Thereafter, the product is subjected to two additional water washings using 1000 parts of water for each wash. The washed reaction product is subsequently distilled to remove unreacted butyl acrylate and toluene. The residue of this first distillation step is subjected to further distillation at a pressure of 9-10 millimeters of mercury whereupon 785 parts of the desired product is collected over the temperature of 105-115°C.

[0095] A mixture of 728 parts (4.0 moles) of the above material, 218 parts (6.8 moles) of sulfur, and 7 parts of triphenyl phosphite is prepared and heated with stirring to a temperature of about 181°C over a period of 1.3 hours. The mixture is maintained under a nitrogen purge at a temperature of 181-187°C for 3 hours. After allowing the material to cool to about 85°C over a period of 1.4 hours, the mixture is filtered using a filter aid, and the filtrate is the desired second sulfurized composition containing 23.1% sulfur.

[0096] The third sulfurized composition (D4c) is prepared by sulfurizing a mixture comprising three essential reagents. This first reagent is a fatty oil; that is, at least one naturally occurring ester of glycerol and a fatty acid, or a synthetic ester of similar structure. Such fatty oils are animal or vegetable oil tryiglycerides of the formula

wherein R¹, R² and R³ are aliphatic groups containing from about 7 to about 23 carbon atoms. A non-exhaustive list of triglycerides include peanut oil, cottonseed oil, soybean oil, sunflower oil and corn oil. These triglycerides are the same as component (A) disclosed above.

[0097] The second reagent is at least one alkenyl carboxylic acid of the formula R²⁵COOH wherein R²⁵ contains about 7 to about 29 carbon atoms. The carboxylic acids are ordinarily free from acetylenic unsaturation. Suitable acids include (preferably) oleic acid, linoleic acid, linolenic acid, 14-hydroxy-11-eicosenoic acid and ricinoleic acid. In particular, the carboxylic acid may be an unsaturated fatty acid such as oleic or linoleic acid, and may be a mixture of acids such as is obtained from tall oil or by the hydrolysis of peanut oil, soybean oil or the like. The amount of carboxylic acid used is about 2-50 parts by weight per 100 parts of triglyceride; about 2-8 parts by weight is preferred.

[0098] The third reagent is at least one substantially aliphatic monoolefin containing from about 4 to about 36 carbon atoms, and is present in the amount of about 25-400 parts by weight per 1000 parts of triglyceride. Suitable olefins include the octenes, decenes, dodecenes, eicosenes and triacontenes, as well as analogous compounds containing aromatic or non-hydrocarbon substituents which are substantially inert in the context of this invention. (As used in the specification and appended claims, the term "substantially inert" when used to refer to solvents, diluents, substituents and the like is intended to mean that the solvent, diluent, substituent, etc. is inert to chemical or physical change under the conditions which it is used so as not to interfere materially in an adverse manner with the preparation, storage, blending and/or functioning of the composition, additive, compound, etc. in the context of its intended use). For example, small amounts of a solvent, diluent, substituent, etc. can undergo minimal reaction or degradation without preventing the making and using of this component as described herein. In other words, such reaction or degradation, while technically discernible, would not be sufficient to deter a worker of ordinary skill in the art from making and using this component for its intended purposes. "Substantially inert" as used herein is, thus, readily understood and appreciated by those of ordinary skill in the art. Terminal olefins, or α - olefins, are preferred, especially those containing from about 12 to about 20 carbon atoms. Especially preferred are straight chain α olefins. Mixtures of these olefins are commercially available and such mixtures are contemplated for use in this invention.

[0099] This sulfurized composition is prepared by reacting a mixture comprising a triglyceride, a fatty acid and an aliphatic monoolefin with a sulfurizing agent at a temperature between about 100°C and about 250°C, usually between about 150° and about 210°C. The sulfurizing reagent may be, for example, sulfur, a sulfur halide such as sulfur monochloride or sulfur dichloride, a mixture of hydrogen sulfide and sulfur dioxide, or the like. Elemental sulfur is often preferred and the invention especially contemplates the use of sulfurized composition prepared by reacting sulfur with the aforesaid mixture. The weight ratio of the combination of triglyceride, fatty acid and aliphatic monoolefin to sulfur is between about 5:1 and about 15:1, generally between about 5:1 and about 10:1.

[0100] In addition to the above described reagents, the reaction mixture may contain other materials. These may include, for example, sulfurization promoters, typically phosphorus-containing reagents such as phosphorous acid esters such as lecithin.

[0101] The sulfurization reaction is effected by merely heating the reagents at the temperature indicated above, usually with efficient agitation and in an inert atmosphere (e.g., nitrogen). If any of the reagents, especially the aliphatic monoolefin, are appreciably volatile at the reaction temperature, the reaction vessel may be maintained under pressure. It is frequently advantageous to add sulfur portionwise to the mixture of the other reagents. While it is usually preferred of the reagent previously described, the reaction may also be effected in the presence of a substantially inert organic diluent (e.g., an alcohol, ether, ester, aliphatic hydrocarbon, halogenated aromatic hydrocarbon or the like) which is liquid within the temperature range employed. When the reaction temperature is relatively high, e.g., about 200°C, there may be some evolution of sulfur from the product which is avoided if a lower reaction temperature (e.g., from about 150° to about 170°C) is used. However, the reaction sometimes requires a longer time at lower temperatures and an adequate sulfur content is usually obtained when the temperature is at the high end of the recited range.

[0102] Following the reaction, volatile materials may be removed by blowing with air or nitrogen and insoluble by products by filtration, usually at an elevated temperature (from about 80° to about 120°C). The filtrate is the desired sulfur product.

[0103] U.S. Patent Nos. 3,926,822 and 3,953,347 are incorporated by reference herein for their disclosures of a suitable sulfurized mixture of triglyceride, carboxylic acid and aliphatic monoolefin. Several specific sulfurized compositions are described in examples 10-18 of 3,926,822 and 10-19 of 3,953,347. The following example illustrates the preparation of one such composition. (In the specification and claims, all parts and percentages are by weight unless otherwise indicated.)

Example (D4c)-1

[0104] A mixture of 100 parts of soybean oil, 5.25 parts of tall oil acid and 44.8 parts of commercial C_15-18 straight chain ∝ - olefins is heated to 167°C under nitrogen, and 17.4 parts of sulfur is added. The temperature of the mixture rises to 208°C. Nitrogen is blown over the surface at 165°-200°C for 6 hours and the mixture is then cooled to 90°C and filtered. The filtrate is the desired product and contains 10.6% sulfur.

(D5) The Derivative Of A Dimercaptothiadiazole

[0105] The dimercaptothiadiazole derivatives which can be utilized as component (D5) in the composition of the present invention contain the dimercaptothiadiazole nucleus have the following structural formulae and names:

2,5-dimercapto-1,3,4-thiadiazole

3,5-dimercapto-1,2,4-thiadiazole

3,4-dimercapto-1,2,5-thiadiazole

4,5-dimercapto-1,2,3-thiadiazole

Of these the most readily available, and the one preferred for the purpose of this invention, is 2,5-dimercapto-1,3,4-thiadiazole. This compound will sometimes be referred to hereinafter as DMTD. However, it is to be understood that any of the other dimercaptothiadiazoles may be substituted for all or a portion of the DMTD.

[0106] DMTD is conveniently prepared by the reaction of one mole of hydrazine, or a hydrazine salt, with two moles of carbon disulfide in an alkaline medium, followed by acidification.

[0107] Derivatives of DMTD have been described in the art, and any such compounds can be included in the compositions of the present invention. The preparation of some derivatives of DMTD is described in E.K. Fields "Industrial and Engineering Chemistry", 49, p. 1361-4 (September 1957). For the preparation of the oil-soluble derivatives of DMTD, it is possible to utilize already prepared DMTD or to prepare the DMTD in situ and subsequently adding the material to be reacted with DMTD.

[0108] U.S. Patents 2,719,125; 2,719,126; and 3,087,937 describe the preparation of various 2,5-bis-(hydrocarbon dithio)-1,3,4-thiadiazoles. The hydrocarbon group may be aliphatic or aromatic, including cyclic, alicyclic, aralkyl, aryl and alkaryl. Such compositions are effective corrosion-inhibitors for silver, silver alloys and similar metals. Such polysulfides which can be represented by the following general formula

wherein R and R' may be the same or different hydrocarbon groups, and x* and y* be integers from 0 to about 8, and the sum of x* and y* being at least 1. A process for preparing such derivatives is described in U.S. Patent 2,191,125 as comprising the reaction of DMTD with a suitable sulfenyl chloride or by reacting the dimercapto diathiazole with chlorine and reacting the resulting disulfenyl chloride with a primary or tertiary mercaptan. Suitable sulfenyl chlorides useful in the first procedure can be obtained by chlorinating a mercaptan (RSH or R'SH) with chlorine in carbon tetrachloride. In a second procedure, DMTD is chlorinated to form the desired bissulfenyl chloride which is then reacted with at least one mercaptan (RSH and/or R'SH). The disclosures of U.S. Patents 2,719,125; 2,719,126; and 3,087,937 are hereby incorporated by reference for their description of derivatives of DMTD useful in the compositions of the invention.

[0109] U.S. Patent 3,087,932 describes a one-step process for preparing 2,5-bis (hydrocarbyldithio)-1,3,4-thiadiazole. The procedure involves the reaction of either DMTD or its alkali metal or ammonium salt and a mercaptan in the presence of hydrogen peroxide and a solvent. Oil-soluble or oil-dispersible reaction products of DMTD can be prepared also by the reaction of the DMTD with a mercaptan and formic acid. Compositions prepared in this manner are described in U.S. Patent 2,749,311. Any mercaptan can be employed in the reaction although aliphatic and aromatic mono- or poly-mercaptan containing from 1 to 30 carbon atoms are preferred. The disclosures of U.S. Patents 3.087,932 and 2,749,311 are hereby incorporated by reference for their description of DMTD derivatives which can be utilized as a metal passivator.

[0110] Carboxylic esters of DMTD having the general formula

wherein R and R' are hydrocarbon groups such as aliphatic, aryl and alkaryl groups containing from about 2 to about 30 or more carbon atoms are described in U.S. Patent 2,760,933. These esters are prepared by reacting DMTD with an organic acid halide (chloride) and a molar ratio of 1:2 at a temperature of from about 25 to about 130°C. Suitable solvents such as benzene or dioxane can be utilized to facilitate the reaction. The reaction product is washed with dilute aqueous alkali to remove hydrogen chloride and any unreacted carboxylic acid. The disclosure of U.S. Patent 2,760,933 is hereby incorporated by reference for its description of various DMTD derivatives which can be utilized in the compositions of the present invention.

[0111] Condensation products of alpha-halogenated aliphatic monocarboxylic acids having at least 10 carbon atoms with DMTD are described in U.S. Patent 2,836,564. These condensation products generally are characterized by the following formula

wherein R is an alkyl group of at least 10 carbon atoms. Examples of alpha-halogenated aliphatic fatty acids which can be used include alpha-bromo-lauric acid, alphachloro-lauric acid, alpha-chloro-stearic acid, etc. The disclosure of U.S. Patent 2,836,564 is hereby incorporated by reference for its disclosure of derivatives of DMTD which can be utilized in the compositions of the present invention.

[0112] Oil-soluble reaction products of unsaturated cyclic hydrocarbons and unsaturated ketones are described in U.S. Patents 2,764,547 and 2,799,652, respectively, and a disclosure of these references also are hereby incorporated by reference for their description of materials which are useful as a DMTD derivative in the present invention. Examples of unsaturated cyclic hydrocarbons described in the '547 patent include styrene, alpha-methyl styrene, pinene, dipentene, cyclopentadiene, etc. The unsaturated ketones described in U.S. Patent 2,799,652 include aliphatic, aromatic or heterocyclic unsaturated ketones containing from about 4 to 40 carbon atoms and from 1 to 6 double bonds. Examples include mesityl oxide, phorone, isophorone, benzal acetophenone, furfural acetone, difurfuryl acetone, etc.

[0113] U.S. Patent 2,765,289 describes products obtained by reacting DMTD with an aldehyde and a diaryl amine in molar proportions of from about 1:1:1 to about 1:4:4. The resulting products are suggested as having the general formula

wherein R and R' are the same or different aromatic groups, and R" is hydrogen, and alkyl group, or an aromatic group. The aldehydes useful in the preparation of such products as represented by Formula X include aliphatic or aromatic aldehydes containing from 1 to 24 carbon atoms, and specific examples of such aldehydes include formaldehyde, acetaldehyde, benzaldehyde, 2-ethylehexyl aldehyde, etc. The disclosure of this patent also is hereby incorporated by reference for its identification of various materials which can be utilized in the compositions of this invention.

[0114] Amine salts of DMTD such as those having the following formula

in which Y is hydrogen or the amino group

in which R is an aliphatic, aromatic or heterocyclic group, containing from about 6 to about 60 carbon atoms also have utility as component (D5). The amine used in the preparation of the amine salts can be aliphatic or aromatic mono- or polyamines, and the amines may be primary, secondary or tertiary amines. Specific examples of suitable amines include hexylamine, dibutylamine, dodecylamine, ethylenediamine, propylenediamine, tetraethylenepentamine, and mixtures thereof. The disclosure of U.S. Patent 2,910,439 is hereby incorporated by reference for its listing of suitable amine salts.

[0115] Dithiocarbamate derivatives of DMTD are described in U.S. Patents 2,690,999 and 2,719,827. Such compositions can be represented by the following formulae

and

wherein the R groups are straight-chain or branch-chain saturated or unsaturated hydrocarbon groups selected from the group consisting of alkyl, aralkyl and alkaryl groups. The disclosures of these two patents also are hereby incorporated by reference for the identification of various thiadiazyl dithiocarbamates which are useful in the compositions of the present invention.

[0116] U.S. Patent 2,850,453 describes products which are obtained by reacting DMTD, an aldehyde and an alcohol or an aromatic hydroxy compound in a molar ratio of from 1:2:1 to 1:6:5. The aldehyde employed can be an aliphatic aldehyde containing from 1 to 20 carbon atoms or an aromatic or heterocyclic aldehyde containing from about 5 to about 30 carbon atoms. Examples of suitable aldehydes include formaldehyde, acetaldehyde, benzaldehyde. The reaction can be conducted in the presence or absence of suitable solvents by (a) mixing all of the reactants together and heating, (b) by first reacting an aldehyde with the alcohol or the aromatic 2-hydroxy compound, and then reacting the resultant intermediate with the thiadiazole, or (c) by reacting the aldehyde with thiadiazole first and the resulting intermediate with the hydroxy compound. The disclosure of U.S. Patent 2,850,453 is hereby incorporated by reference for its identification of various materials which can be utilized in the compositions of the present invention.

[0117] U.S. Patent 2,703,784 describes products obtained by reacting DMTD with an aldehyde and a mercaptan. The aldehydes are similar to those disclosed in U.S. Patent 2,850,453, and the mercaptans may be aliphatic or aromatic mono- or poly-mercaptans containing from about 1 to 30 carbon atoms. Examples of suitable mercaptans include ethyl mercaptan, butyl mercaptan, octyl mercaptan, thiophenol. etc. The disclosure of this patent also is incorporated by reference.

[0118] The preparation of:
2-hydrocarbyldithio-5-mercapto-1,3,4-thiadiazoles having the formula

wherein R' is a hydrocarbyl substituent is described in U.S. Patent 3,663,561. The compositions are prepared by the oxidative coupling of equimolecular portions of a hydrocarbyl mercaptan and DMTD or its alkali metal mercaptide. The compositions are reported to be excellent sulfur scavengers and are useful in preventing copper corrosion by active sulfur. The mono-mercaptans used in the preparation of the compounds are represented by the formula

        R'SH

wherein R' is a hydrocarbyl group containing from 1 to about 280 carbon atoms. A peroxy compound, hypohalide or air, or mixtures thereof can be utilized to promote the oxidative coupling. Specific examples of the monomercaptan include methyl mercaptan, isopropyl mercaptan, hexyl mercaptan, decyl mercaptan, and long chain alkyl mercaptans, for example mercaptans derived from propene polymers and isobutylene polymers especially polyisobutylenes. having 3 to about 70 propene or isobutylene units per molecule. The disclosure of U.S. Patent 3,663,561 is hereby incorporated by reference for its identification of DMTD derivative which are useful as in the compositions of this invention.

[0119] Another material useful as component (D5) in the compositions of the present invention is obtained by reacting a thiadiazole, preferably DMTD with an oil-soluble dispersant, preferably a substantially neutral or acidic carboxylic dispersant in a diluent by heating the mixture above about 100°C. This procedure, and the derivatives produced thereby are described in U.S. Patent 4,136,043, the disclosure of which is hereby incorporated by reference. The oil-soluble dispersants which are utilized in the reaction with the thiadiazoles are often identified as "ashless dispersants". Various types of suitable ashless dispersants useful in the reaction are described in '043 patent.

[0120] Another material useful as component (D5) in the compositions of the invention is obtained by reacting a thiadiazole, preferably DMTD, with a peroxide, preferably hydrogen peroxide. The resulting nitrogen- and sulfur-containing composition is then reacted with a polysulfide, mercaptan or amino compound (especially oil-soluble, nitrogen-containing dispersants). This procedure and the derivatives produced thereby are described in U.S. Patent 4,246,126, the disclosure of which is incorporated herein by reference.

[0121] U.S. Patent 4,140,643 describes nitrogen and sulfur-containing compositions which are oil-soluble and which are prepared by reacting a carboxylic acid or anhydride containing up to about 10 carbon atoms and having at least one olefinic bond with compositions of the type described in U.S. Patent 4,136,043. The preferred carboxylic acid or anhydride is maleic anhydride. The disclosures of U.S. Patents 4,136,043 and 4,140,643 are hereby incorporated by reference for their disclosures of materials useful as component (D5) in the compositions of the present invention.

[0122] U.S. Patent 4,097,387 describes DMTD derivatives prepared by reacting a sulfur halide with an olefin to form an intermediate which is then reacted with an alkali metal salt of DMTD. More recently, U.S. Patent 4,487,706 describes a DMTD derivative prepared by reacting an olefin, sulfur dichloride and DMTD in a one-step reaction. The olefins generally contain from about 6 to 30 carbon atoms. The disclosures of U.S. Patents 4,097,387 and 4,487,706 are hereby incorporated by reference for their descriptions of oil-soluble DMTD derivatives which are useful as component (D5) in the compositions of this invention.

[0123] The compositions of the present invention comprising components (A) and (B) or (A) and (B) with (C) or (D) or with (C) and (D) are useful as viscosity modified environmentally friendly farm tractor lubricants and chain bar lubricants and hydraulic fluids.

[0124] When the composition comprises components (A) and (B), the following states the ranges of these components in parts by weight:

Component	Generally	Preferred	Most Preferred
(A)	80 - 99.5	90 - 99.5	96 - 99
(B)	0.5 - 20	0.5 - 10	1 - 4

[0125] When the composition comprises components (A), (B) and (C); or (A), (B) and (D), the following states the range of these components in parts by weight:

Component	Generally	Preferred	Most Preferred
(A)	80 - 99.5	90 - 99.5	93 - 98.5
(B)	0.5 - 12	0.5 - 6	1 - 4
(C) or (D)	0.5 - 8	0.5 - 4	0.5 - 3

[0126] When the composition comprises components (A), (B), (C) and (D), the following states the range of these components in parts by weight:

Component	Generally	Preferred	Most Preferred
(A)	80 - 99	90 - 99	91 - 98
(B)	0.5 - 10	0.5 - 6	1 - 5
(C)	0.25 - 5	0.25 - 2	0.5 - 2
(D)	0.25 - 5	0.25 - 2	0.5 - 2

[0127] It is understood that other components besides (A), (B), (C) and (D) may be present within the composition of this invention.

[0128] The components of this invention are blended together according to the above ranges to effect solution. Ther following Table II outlines examples so as to provide those of ordinary skill in the art with a complete disclosure and description on how to make the compositions of this invention and is not intended to limit the scope of what the inventor regards as the invention. All parts are by weight.

[0129] While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fallwithin the scope of the appended claims.

Table II

Example	(A)	(B)	Visc 40° cSt	Vis 100°C cSt
1	100 parts Sunyl 80 oil		39.52	8.65
2	99 parts Sunyl 80 oil	1 part Glissoviscal SGH	63.57	13.16
3	98 parts Sunyl 80 oil	2 parts Glissoviscal SGH	117.97	20.11
4	97 parts Sunyl 80 oil	3 parts Glissoviscal SGH	268.85	30.70
5	96 parts Sunyl 80 oil	4 parts Glissoviscal SGH	705.67	46.21
6	95 parts Sunyl 80 oil	5 parts Glissoviscal SGH	1915.2	70.43
7	94 parts Sunyl 80 oil	6 parts Glissoviscal SGH	5007.4	113.37
8	92 parts Sunyl 80 oil	8 parts Glissoviscal SGH	10,000	344.4
9	90 parts Sunyl 80 oil	10 parts Glissoviscal SGH	88,600	1181.0
10	99 parts Sunyl 80 oil	1 part Glissoviscal CE-5260	61.56	12.50
11	98 parts Sunyl 80 oil	2 parts Glissoviscal CE-5260	98.70	18.74
12	97 parts Sunyl 80 oil	3 parts Glissoviscal CE-5260	152.56	25.72
13	96 parts Sunyl 80 oil	4 parts Glissoviscal CE-5260	242.05	36.65
14	95 parts Sunyl 80 oil	5 parts Glissoviscal CE-5260	392.20	49.23
15	94 parts Sunyl 80 oil	6 parts Glissoviscal CE-5260	694.21	72.17
16	92 parts Sunyl 80 oil	8 parts Glissoviscal CE-5260	2487.9	140.09
17	90 parts Sunyl 80 oil	10 parts Glissoviscal CE-5260	9919.0	265.88

Claims

1. A composition, comprising

(A) a major amount of at least one natural oil or synthetic triglyceride of the formula

wherein R¹, R² and R³ are aliphatic groups that contain from about 7 to about 23 carbon atoms, and

(B) a minor amount of a composition comprising a hydrogenated aliphatic conjugated diene/mono-vinyl aromatic random block copolymer having a number average molecular weight of the random block copolymer of more than 300,000 and wherein the random block copolymer has about 30 to about 80 percent by weight aliphatic conjugated dienes and about 20 to about 70 per cent by weight mono-vinyl aromatic monomers.

2. The composition of claim 1 wherein the natural oil is a vegetable oil that comprises sunflower oil, safflower oil, corn oil, soybean oil, rapeseed oil, coconut oil, lesquerella oil, castor oil, canola oil and peanut oil.

3. The composition of claim 1 wherein the synthetic triglyceride is an ester of at least one straight chain fatty acid and glycerol wherein the fatty acid contains from about 8 to about 22 carbon atoms.

4. The composition of claim 1 wherein the natural oil is a genetically modified vegetable oil where R¹, R² and R³ are aliphatic groups that are at least 60 percent monounsaturated wherein the genetically modified vegetable oil comprises genetically modified sunflower oil, genetically modified corn oil, genetically modified soybean oil, genetically modified rapeseed oil, genetically modified canola oil, genetically modified safflower oil or genetically modified peanut oil.

5. The composition of claim 4 wherein the monounsaturated character is due to an oleic acid residue wherein an oleic acid moiety:linoleic acid moiety ratio is from 2 up to about 90.

6. The composition of any preceding claim wherein said aliphatic conjugated diene is isoprene or butadiene, wherein said mono-vinyl substituted aromatic monomer is styrene or an alkyl substituted styrene wherein the alkyl group contains from 1 up to about 4 carbon atoms and wherein hydrogenation of the random block copolymer removes at least 94 percent of the original olefinic unsaturation.

7. The composition of any preceding claim further comprising (C) at least one oxidation inhibitor wherein the oxidation inhibitor (C) comprises

(1) an alkyl phenol of the formula

wherein R⁴ is an alkyl group containing from 1 up to about 24 carbon atoms, a is an integer of from 1 up to 3 and z is 1 or 2:

(2) an aromatic amine of the formula

wherein b is 1 or 2 and when b is 1, R⁵ is

and R⁶ and R⁷ are independently a hydrogen or an alkyl group containing from 1 up to about 24 carbon atoms, and when b is 2, R⁵ and R⁶ are independently hydrogen, an aryl group or an alkyl group containing from 1 up to about 18 carbon atoms; or

(3) a heterocyclic amine of the formulae (a) or (b)

wherein R⁸ is independently a hydrogen or an alkyl group containing from 1 up to about 4 carbon atoms, Z is hydrogen or →O• and X is hydrogen, -NR¹⁴R¹⁵ or OR¹⁵ wherein R¹⁴ and R¹⁵ are independently hydrogen or alkyl groups containing from 1 up to about 18 carbon atoms;

   (D) at least one extreme pressure/anti-wear additive wherein the extreme pressure/anti-wear additive (D) comprises

(1) a metal sulfur/phosphorus salt of the formula

wherein R⁹ and R¹⁰ are independently hydrocarbyl groups containing from 3 up to about 20 carbon atoms, M' is a metal selected from lithium, sodium, calcium, barium, copper, zinc, antimony, tin, cerium and other members of the lanthanide series, and x is the valence of M¹;

(2) a metal sulfur/nitrogen salt of the formula

wherein R¹¹ and R¹² are independently hydrocarbyl groups containing from 1 up to about 24 carbon atoms, M² is a metal moiety selected from copper, zinc, antimony, tin, cerium and other members of the lanthanide series and a molybdenum cation selected from -Mo=O and O=Mo=O, and y is the valence of M²;

(3) a benzotriazole of the formula

wherein R¹³ is hydrogen or an alkyl group containing from 1 up to about 12 carbon atoms, R¹⁶ is hydrogen or -CH₂SR¹⁷ wherein R¹⁷ is an alkyl group containing from 1 up to about 18 carbon atoms; and

(4) a sulfurized composition, and

(5) a derivative of a dimercaptothiadiazole; or
 mixtures of (C) and (D).

8. The composition of claim 7 wherein within the alkyl phenol z is 1, R4 is t-butyl and a is 2.

9. The composition of claim 7 or claim 8 wherein within the aromatic amine when b is 1, R⁵ is

and R⁶ and R⁷ are both nonyl groups.

10. The composition of claim 7 or claim 8 wherein within the aromatic amine when b is 2, R⁵ is

and R⁶ and R⁷ are both hydrogen.

11. The composition of any one of claims 7 to 10 wherein within the heterocyclic amine of the formula (C3a) R⁸ is methyl, Z is →0• and X is hydrogen.

12. The composition of any one of claims 7 to 11 wherein within the heterocyclic amine of the formula (C3a) R⁸ is methyl and X and Z are both hydrogen.

13. The composition of any one of claims 7 to 10 wherein within the heterocyclic amine of the formula (C3a) R⁸ is methyl, X is -OR¹⁵ and R¹⁵ and Z are both hydrogen.

14. The composition of any one of claims 7 to 10 wherein within the heterocyclic amine of the formula (C3b) R⁸ is methyl and Z is hydrogen or→0•.

15. The composition of any one of claims 7 to 14 wherein within the benzotriazole R¹³ is methyl and R¹⁶ is hydrogen.

16. The composition of any one of claims 7 to 15 wherein the sulfurized composition (4) comprises a sulfurized olefinic hydrocarbon wherein the sulfurized olefinic hydrocarbon (a) is prepared by reacting an olefin/sulfur halide adduct by contacting the olefin/sulfur halide adduct with sodium sulfide or sodium polysulfide in a protic solvent under basic conditions at a temperature in the range of 40°C to 120°C, removing halogens from the sulfurized olefin/sulfur halide adduct and providing a complex polysulfide product; or

(b) the sulfurized composition comprises the reaction product of sulfur and a Diels-Alder adduct in a molar ratio of sulfur to Diels-Alder adduct of from about 1:2 to about 4:1 wherein the Diels-Alder adduct comprises at least one dienophile selected from alpha, beta ethylenically unsaturated aliphatic carboxylic acid esters, alpha, beta ethylenically unsaturated aliphatic carboxylic acid amides, alpha, beta ethylenically unsaturated aliphatic halides alkylacrylates and alpha methyl alkylacrylates wherein the alkyl group contains from 1 to 10 carbon atoms with at least one aliphatic conjugated diene corresponding to the formula

where R¹⁸ through R²³ are each independently selected from hydrogen, alkyl, alkoxy, alkenyl, carboxy, cyano, phenyl, and phenyl substituted with one to three substituents corresponding to R¹⁸ through R²³; or

(c) a sulfurized mixture of a triglyceride wherein the triglyceride is a vegetable oil triglyceride comprising peanut oil, cottonseed oil, soybean oil, corn oil, safflower oil, canola oil, sunflower oil and rapeseed oil of the formula

wherein R¹, R² and R³ are aliphatic groups containing from about 7 up to about 23 carbon atoms, a carboxylic acid wherein the carboxylic acid is an alkenyl carboxylic acid of the formula

        R²⁵ COOH

wherein R²⁵ contains from 7 up to about 29 carbon atoms, and an olefin wherein the olefin is an aliphatic monoolefin that contains from 4 up to about 36 carbon atoms.

17. The composition of claim 16 wherein within (D4a), the olefin is an alkylene compound containing one double bond and 2 to 50 carbon atoms, and the sulfur halide is a sulfur chloride.

18. The composition of claim 16 wherein within (D4a), the olefin is a mixture of olefins containing isobutene and the sulfur halide is selected from sulfur monochloride, sulfur dichloride and mixtures thereof; the protic solvent is selected from water, alcohols, carboxylic acids and combination thereof and the sodium sulfide/sodium polysulfide mixture is derived from hydrocarbon purification process streams.

19. The composition of any one of claims 16 to 18 wherein within (D4b), the molar ratio of sulfur to adduct is from about 2:1 to about 4:1.

20. The composition of claim 19 wherein within (D4b), the diene is further characterized in that R²⁰ and R²¹ are hydrogen and R¹⁸, R¹⁹, R²² and R²³ are each independently hydrogen, chloro, or lower alkyl.

21. The composition of claim 20 wherein within (D4b), the diene is piperylene, isoprene, methylisoprene, chloroprene, or 1,3-butadiene and the dienophile is an ester of acrylic acid or methacrylic acid.

22. The composition of claim 20 wherein the dienophile is butyl acrylate or butyl methacrylate and the diene is 1,3-butadiene.

23. The composition of any one of claims 16 to 22 wherein the weight ratio of the combination of triglyceride, carboxylic acid and olefin to sulfur is about 5-15:1.