EP0739405A1

EP0739405A1 - Additives for lubricants

Info

Publication number: EP0739405A1
Application number: EP95907404A
Authority: EP
Inventors: John Phillips Doner; Liehpao Oscar Farng
Original assignee: Mobil Oil AS; Mobil Oil Corp
Current assignee: Mobil Oil AS; ExxonMobil Oil Corp
Priority date: 1994-01-13
Filing date: 1995-01-11
Publication date: 1996-10-30
Also published as: CA2179814A1; JPH09508156A; WO1995019411A1; KR970700759A; EP0739405A4; AU1564795A

Abstract

Pre-blended combinations and reaction products of at least one metallic dithiocarbamate and at least one metallic dithiophosphate provide the synergism of antiwear properties with friction-reducing properties for lubricants and greases.

Description

ADDITIVES FOR LUBRICANTS

This invention is directed to combinations and reaction products of metallic dithiocarbamates and metallic dithiophosphates, and their use as additives in lubricants because of their synergistic properties. More particularly,it is directed to compositions of lubricants and greases containing such additives.

Mechanical systems under heavy loads will deteriorate due to the frictional forces created by relatively moving, rubbing and bearing metal surfaces. Often, lubricants for such operations cannot prevent wear of the metal nor reduce the coefficient of friction and as a result the system performance is affected. Antiwear additives and friction modifying additives are frequently blended with lubricants in order to prevent wear, reduce fuel consumption and increase the operating life of the machinery. The term "anti-load" is in some instances used instead of "antiwear", but the term "antiwear" is used throughout this disclosure. In order to minimize wear, various additives have been added in the past to lubricants to produce a protective surface film on the metal parts. However, the antiwear lubricants may exhibit other unsatisfactory lubricating characteristics such as corrosive wear due to chemical reaction between the additive and the metal surfaces, and deterioration due to oxidation under high temperature conditions. Supplemental lubricating additives may subsequently be necessary in order to prevent such detrimental effects. In order to minimize friction, various friction- reducing additives have been added to lubricants to produce a smooth surface film. However, the friction additives may dominate the metal surface and prevent the anti-wear additives from encountering the surface to form an effective film. Friction and wear are two different phenomena. Often,it is difficult to prevent wear and reduce friction simultaneously, even in the presence of both antiwear additives and friction-modifying additives. The instant invention provides unexpected results by providing both low friction and low wear properties in a single additive formulation. Synergism can be obtained by the use of pre-blended combinations of specific antiwear and friction-modifying agents or reaction products of such agents. Synergistic behavior cannot be achieved through the simple component blending process (i.e., lubricant and grease formulation blending) . This invention is very significant to applications involving machinery,bearings and joint lubrication.

Lubricants, such as lubricating oils and greases, are subject to oxidative deterioration at elevated temperatures or upon prolonged exposure to the elements or exhaustion of useful life. Such deterioration is evidenced, in many instances, by an increase in both acidity and viscosity, and when the deterioration is severe enough, it can cause metal parts to corrode. Additionally, severe oxidation leads to a loss of lubrication properties, and in especially severe cases this may cause complete breakdown of the device being lubricated.

The metal salts of diorganodithiocarba ic acids have been described as multifunctional, antioxidant, antiwear and corrosion inhibiting additives for lubricants. They are also noted for their metal deactivating properties.

Metallic dithiophosphates are well-known for their use as effective corrosion/oxidation inhibitors as well as anti-wear additives in many lubricant and grease applications, including engine oils and industrial oils.

The beneficial effects of the of the instant invention are believed to be the result of an internal synergism between suitable metal groups, dithiophosphate groups, and dithiocarbamate groups within the same lubricant compositions. The pre-blended combinations and reaction products of this invention show good stability and compatibility when used in the presence of other commonly used additives in grease or lubricant compositions.

The use of metallic dithiocarbamates as additives in rubber and polymer applications is well known in the prior art. U.S. Patent No. 4,278,587 (Wolff et.al) discloses zinc dialkyl dithiocarbamates as effective accelerators and antioxidants. U.S. Patent No. 4,919,830 (Farng et al.) disclosed the use of organic phosphates derived from dithiocarbamates as lubricant additives, having notable antioxidant and anti-wear properties.

U.S. Patent No. 5,002,674 (Farng et al.) discloses that ashless thiophosphates (such as 4,4-methylene bis(dibutyl dithiocarbamate) derived from dihydrocarbyl dithiocarbamates are effective multifunctional additives for lubricants, having antioxidant and antiwear properties. U.S. Patent No. 4,290,202 (Levine et al.) discloses molybdenum dialkyl dithiophosphates which have utility as extreme pressure and antiwear agents. Metallic dithiophosphates (such as zinc or molybdenum dialkyl dithiophosphates) are well known for their use as effective corrosion/oxidation inhibitors as well as antiwear additives in many lubricant and grease applications including engine oils and industrial oils.

U.S. Patent No. 4,360,438 (Rowan et al) discloses synergistic antiwear compositions comprising a sulfurized molybdenum dialkyldithiocarbamate and an organic sulfur compound selected from the group consisting of dithiocarbamate acid esters, sulfurized oils and polysulfurized olefins. Dithiocarbanates are further discussed in an article coauthorized by one of the inventors of '438, H.H. Farmer. The chemistry of dithiocarbamates and their mechanisms are discussed in "Dithiocarbamate Additives in Lubricating Greases", A. F. Polishuk and H. H. Farmer, NLGI Spokesman, September, 1979, pp. 200-205. U.S. Patent No. 2,492,314 (Olin et al) discloses a process for the production of metal salts of substituted dithiocarbamic acids. The preparation of a zinc salt of an alkyl dithiocarbanic acid is one salt disclosed. The instant invention is directed to products of reaction and pre-blended combinations of metallic dithiocarbamates and metallic dithiophosphates, having synergistic anti-wear and friction reducing capacities. Although the reaction products may vary according to the conditions employed, they are effective if their structures contain (a) metal dithiophosphates and (b) metal dithiocarbamates. The metals maybe selected from nickel, antimony, molybdenum, copper, cobalt, iron, cadmium, zinc, manganese, sodium, magnesium, calcium and lead. These products and combinations may be used as additives to lubricants and greases, providing enhanced friction- reducing, and antiwear properties at extreme pressures. They can significantly extend the service life of engines. Additional antioxidation, cleanliness, antifatigue, high temperature stabilizing, and anticorrosion properties are also potentially present. The products of this invention show good stability and compatibility when used in the presence of other commonly used additives in grease or lubricant compositions. They are useful at low concentrations in lubricants.

This invention is directed to additives suitable for use in lubricant oils which are prepared in a process comprising reacting in an appropriate reaction zone (or mixing in pre-blended combinations) a metallic dithiocarbamate and a metallic dithiophosphate. The preferred dithiocarbamates are zinc, nickel and antimony dialkyl dithiocarbamates. The most preferred dithiocarbamate is antimony dialkyl dithiocarbamate. The alkyl groups are preferably 2-30 carbons, more preferably 8 to 15 carbons, in length. Antimony dialkyl dithiocarbamate is illustrated below:

The dithiocarbamates are dark amber liquids, with a viscosity at 100°C of about 50 SUS(7.25 mm 2/s) . The flash point(open cup) is about 17l°C (340°F) . The pour point is about -23°C(-10°F) .

Metallic dithiocarbamates, such as antimony dialkyl dithiocarbamates, may be obtained commercially from the R.T. Vanderbilt Chemical Company (under the trade name VanLube 73)as well as from other sources. Metallic dithiocarbamates may also be synthesized. Sodium dialkyl dithiocarbamates can be synthesized by reacting equal molar amounts of sodium hydroxide, a secondary dialkyl amine, and carbon disulfide in aqueous media or organic solution depending on conditions as illustrated below:

-S-Na+H₂0

Sodium dialkyl dithiocarbamates can also be used to prepare other metal dialkyl dithiocarbanates, such as those containing antimony or zinc. Preparation of an antimony dialkyl dithiocarbamate is illustrated below:

N-C-S Sb + 3NaCL

Zinc dialkyl dithiocarbanates may be made by reacting sodium dialkyl carbamates with ZnSo₄, ZNC1₂ or Zn(OH)₂.

The general blending or reaction conditions when the metallic dithiocarbamate and the metallic dithiophosphate phosphate are combined and may be any suitable conditions known in the art. Temperatures will usually vary from -20° to 250°C. The temperature is preferably between 50°C and 150°C. Reaction rather than blending will usually occur if the temperature is between 70°C and 100"C. If a solvent is used the reaction conditions may vary. Usually atmospheric or ambient pressure is used. However, higher or lower pressures may be used if desired. The time required for reaction will vary primarily with the temperature, pressure and solvent used, if any. If a solvent is used it may be polar or non-polar. Polar solvents include acetones, alcohols, ethers and esters. Non-polar solvents include both aliphatic and aromatic hydrocarbons.

Metallic dithiophosphates useful in the instant invention include molybdenum, zinc, copper, lead, magnesium and cadmium dithiophosphates. Molybdenum dialkyl phosphorothioate is commercially available from several sources. It is sold by R.T. Vanderbilt Chemical Company under the trade name Molyvan L. The most preferred compounds useful in the instant invention are sulfurized oxymolybdenum organophosphorodithioates, illustrated below:

where R represents alkyl or alkylaryl, m = 2 to 3, n = 2 to 1, and m+n = 4.

They have previously been disclosed in U.S. Patent Nos. 3,400,140 and 3,494,866 as well as in U.S. Patent No. 4,290,902. R may be an alkyl, cycloalkyl, aryl, or alkaryl radical. In most cases it is an alkyl chain of 2 to 30 carbons. These dithiophosphates (also known as phosphoro- dithioates) are dark green liquids, with a viscosity at 100°C of about 56 SUS(90 mm 2/s) . The flash poιnt(open cup) is about 166°C(330°F) . The pour point is about -37°C(-

35-F) . In the preparation of molybdenum dialkyl phosphorothioates it is important to use 2 mole of phosphorodithioic acid reactant for each mole of molybdate reactant to obtain a maximum yield, with one phosphoro- dithioate radical per molybdenum atom. No catalyst is required for the reaction. Water is a suitable solvent but other inert solvents may be present, such as a low viscosity aromatic base oil.

The reaction product may be solid or liquid depending on the organic radical in the phosphorodithioic acid reactant. If the molybdenum-containing product is a solid, it is recovered by filtration. If the molybdenum- containing product is a liquid, it is recovered by filtering out any solid by-products and by distilling to remove the solvent.

The dithiophosphates may be prepared by dissolving molybdic oxide in a solution of alkali metal hydroxide, magnesium hydroxide, beryllium hydroxide or ammonium hydroxide and by incorporating subsequently an approximately equivalent amount, based on hydroxide, of a strong mineral acid, such as sulfuric acid. An organophosphorodithioic acid reactant may be alternately prepared by treating a monohydric alcohol or phenol with phosphorus pentasulfide in the mole ratio of 4:1. The phosphorodithioic acid reactant is then added to the molybdate solution with subsequent finishing operations to form a sulfurized oxymolybdenum organophosphorodithioate.

It is important herein to heat the mixture of phosphorodithioic acid and molybdate solution at the reflux temperature, e.g., from 85° to 100°C. The reaction time is generally 1 to 5 hours.

The generalized reaction of the instant invention is as follows (provided a reaction product rather than a blended mixture is made) : R

\

N-C-S -Sb (R-0) ₂-P-S Mθ₂S₂0₂

R

Structure containing suitable metallic groups, i.e. Mo and Sb, dithiophosphate groups and dithiocarbamate groups which act in synergism to provide antiwear-carrying and friction- reducing properties.

In the preparation of the blended combinations and reaction products, an excess of one component or another can be used. Molar quantities, less than molar quantities, or more than molar quantities of either metallic dithio¬ carbamates or metallic dithiophosphates can be used. The metallic dithiocarbamates and the metallic dithiophosphates may be combined in any ratio from 1:9 to 9:1. The base lubricants which are useful with the additives of this invention may be any oil of lubricating viscosity, whether natural or synthetic. The natural oils include paraffinic, naphthenic oils, or mixtures of them, neutral distillates and bright stocks. Among the synthetic oils are polyolefin (synthetic hydrocarbon) fluids, such as the polyolefins and hydrogenated polyolefins, especially the poly (alpha) olefins and hydrogenated poly (alpha) olefins. These are derived from olefins with 5 to 20 carbon atoms, particularly from 8 to 14 carbon atoms such as the poly 1-decenes and hydrogenated poly 1-decenes, as well as polybutenes including polyisobutenes.

Esters of dibasic acids may also be used as synthetic oils. These include the esters of C₆ - C₉ dibasic acids such as sebacic, azelaic and adipic acids having branched chain alcohols, such as 2-ethylhexanol or the C₈ - C₁₀ oxoalcohols. Useful esters include di(2-ethylhexyl)- sebacate, di(2-ethylhexyl)adipate, and dibutylphthalate. Esters of polyols such as the neopentyl polyols including neopentyl glycol, trimethylol propane, triethylol propane and pentaerythritol may also be used as synthetic hydrocarbon oils. The esters of such polyols with monobasic carboxylic acids such as the C₅ - C₉ acids or mixtures of acids are examples.

Polyglycols such as polypropylene glycol, polyethylene glycol, and mixed polyoxyalkylene glycols can also be used as synthetic oils. The base lubricant contemplated may also be a grease formulated by adding a grease-forming quantity of a thickening agent to one of the oils mentioned above. For this purpose a wide variety of materials may be employed. These thickening agents or gelling agents may include any of the conventional metal salts or soaps which are dispersed in the lubricating oil in grease-forming quantities in such degree as to impart to the resulting grease the desired consistency. Other thickening agents that may be employed in the formulation may comprise non- soap thickeners, such as modified clays and silicas and aryl ureas.

To achieve the purposes of this invention the lubricant compositions should contain from 0.01 to 8 wt.% and more preferably from 1.5 to 6 wt.% of the previously described synergistic preparation. Any other lubricant additives may be also incorporated, up to about 15 wt. % into the lubricant compositions for their known purposes.

Having described the invention broadly, the following are offered as specific illustrations. They are illustrative only and are not intended to limit the invention. EXAMPLE 1

A Preblended Combination of Molybdenum Dithiophosphate and Antimony Dithiocarbamate

Approximately 17 gm of molybdenum di-2-ethylhexyl dithiophosphate (commercially obtained from R.T. Vanderbilt Chemical Company under the trade name Molyvan L) and 3 gm of antimony diamyl dithiocarbamate (commercially obtained from R.T. Vanderbilt Chemical Company under the trade name Vanlube 73) were blended together in a mixer at room temperature for one hour. Thereafter, approximately 20 gm of yellow-green liquid was recovered as desired blending product.

EXAMPLE 2 A Preblended Combination of Molybdenum Dithiophosphate and Antimony Dithiocarbamate

Approximately 14 gm of molybdenum di-2-ethylhexyl dithiophosphate and 6 gm of antimony diamyl dithiocarbamate were blended together in a mixer at room temperature for an hour. Thereafter, approximately 20 gm of yellow-green liquid was recovered as desired blending product.

EXAMPLE 3

Approximately 10 gm of molybdenum di-2-ethylhexyl dithiophosphate and 10 gm of antimony diamyl dithiocarbamate were blended together in a mixer at room temperature for an hour. Thereafter, approximately 20 gm of yellow-green liquid was recovered as desired blending product. EXAMPLE 4

A Reaction Product of Molybdenum Dithiophosphate and Antimony Dithiocarbamate

Approximately 17 gm of molybdenum di-2-ethylhexyl dithiophosphate (commercially obtained from R.T. Vanderbilt Chemical Company under the trade name Molyvan L) and 3 gm of antimony diamyl dithiocarbamate (commercially obtained from R.T. Vanderbilt Chemical Company under the trade name Vanlube 73) were blended together in a mixer at 80°C for an hour. Thereafter, approximately 20 gm of yellow-green liquid was recovered as desired blending product.

EXAMPLE 5

A Reaction Product of Molybdenum Dithiophosphate and Antimony Dithiocarbamate Approximately 14 gm of molybdenum di-2-ethylhexyl dithiophosphate and 6 gm of antimony diamyl dithiocarbamate were blended together in a mixer at 80°C for one hour. Thereafter, approximately 20 gm of yellow-green liquid was recovered as desired product.

EXAMPLE 6

A Reaction Product of Molybdenum Dithiophosphate and Antimony Dithiocarbamate

Approximately 10 gm of molybdenum di-2-ethylhexyl dithiophosphate and 10 gm of antimony diamyl dithiocarbamate were blended together in a mixer at 80°C for one hour. Thereafter, approximately 19.5 gm of yellow- green mixture was recovered as desired product.

EXAMPLE 7 A Reaction Product of Molybdenum Dithiophosphate and Antimony Dithiocarbamate

Approximately 85 gm of molybdenum di-2-ethylhexyl dithiophosphate and 15 gm of antimony diamyl dithio- carbamate were blended together in a mixer at 80°C for one hour, then at 100°C for another hour. Thereafter, a mixture of green liquid and yellow solid was recovered as desired product.

EXAMPLE 8

A Reaction Product of Molybdenum Dithiophosphate and Antimony Dithiocarbamate

Approximately 50 gm of molybdenum di-2-ethylhexyl dithiophosphate and 50 gm of antimony diamyl dithiocarbamate were blended together in a mixer at 80°C for one hour, then at 100°C for another hour. Thereafter, a mixture of green liquid and yellow solid was recovered as desired product.

Wear Reducing Properties The products of the Examples were blended into a non- additized lithium grease and evaluated for antiwear performance using the 4-Ball Wear Test at 1200 rpm, 40 kg load, 60 minutes, at 75°C (167°F). Reported is the wear scar diameter (WSD) in millimeters and cF, the coefficient of friction. The products of the examples were blended into the base grease at the concentration indicated in Table 1.

In the Four Ball Wear Test, three stationary balls are placed in the reference lubricant or base grease, in this case a paraffinic-naphthenic mineral oil plus a lithium thickener made from a blend of 12-hydroxy and tallow fatty acids. The compound to be tested is added thereto, and a fourth ball is placed is placed in a chuck mounted on a device which can be used to spin the ball at known speeds and loads. The samples were tested using 0.5 inch stainless steel balls of 52100 steel for a known period of time, typically 30 to 60 minutes. The diameters of the wear scars are measured after completion of the test. F-7276

TABLE 1 Four-Ball Wear Test (ASTM D-2266)

40 Kg. 1200 rpm. 75"C. 60 min.

Item WSD (mm) Coeff. of Friction

5 Base grease (paraffinic-naphthenic mineral 0.525 0.096 oils plus a lithium thickener made from a (0.633)* (0.092)* a blend of 12-hydroxy and tallow fatty acids)

6% Example 3 in base grease 0.413 0.065 6% Example 6 in base grease 0.430 0.053

10 3% Example 3 in base grease 0.430 0.065 3% Example 6 in base grease 0.393 0.073 3% Example 8 in base grease 0.458 0.044

1.5% Example 3 in base grease 469 0.075

1.5% Example 6 in base grease 424 0.079

15 1.5% Example 8 in base grease 0.400 0.063

6% Example 1 in base grease 0.404 0.071 6% Example 4 in base grease 0.375 0.067

3% Example 1 in base grease 0.067

3% Example 4 in base grease 0.404 0.065

20 3% Example 7 in base grease 0.400 0.061

1.5% Example 1 in base grease 0.379 0.083 1.5% Example 4 in base grease 0.420 0.073

♦Duplicated run

The results above demonstrate that the additives of the examples exhibit friction reducing activities and considerable antiwear activity. The most effective grease and additive compositions are 6% Example 4 and 3% Example 8, since they have the smallest wear scar diameters and coefficients of friction, respectively, in comparison with the base grease.

Cameron Plint Wear Test

The Cameron-Plint Wear test measures frictional force employing a reciprocating friction machine. The machine employs a line contact as opposed to a point contact (a point contact uses a ball on a flat surface) . The line contact specimen configuration operates at 50 Hz, 100 N load, and a 0.76 mm stroke. The temperatures are ramped from 50 to 165°C. The duration of the test was 30 minutes. Sample specimens consisted of a hardened steel (62 Rockwell C) ground gauge plate, finished to a surface roughness of 0.45 microns, and a 16 mm long nitride steel dowel pin as the contact (6mm diameter, 60 Re) . Metallurgy for the plate and line contact are defined in British Standards BS 4659 and BS 1804 respectively. The steel specimens were immersed in approximately 10 ml of lubricant. Friction coefficients were calculated from frictional force by dividing by the load value,typically 100N, and were generally repeatable to +/-0.005.

TABLE 2

Cameron Plint Wear Test

(100 N, 0.76 mm stroke, 50 Hz, 50°C, and 30 Min.)

Wear Scar Coefficient Item Diameter (mm. of Friction

Base grease (paraffinic- 0.270 0.079 naphthenic mineral oils plus a lithium thickener made from a blend of 12- hydroxy and tallow fatty acids)

Plus 4% Example 4 0.308 0.043

Plus 4% Example 5 0.330 0.041

Plus 4% Example 6 0.325 0.048

In Table 2, the grease compositions containing the additives of the examples show a decrease in the friction coefficient from that of the base grease.

Optimal SRV Friction and Wear Test

The Optimal SRV Friction and Wear Test evaluates the friction, wear and breakaway torque characteristics of lubricants and materials under high-speed oscillation. A mobile specimen oscillates on a fixed specimen to simulate rolling and sliding friction. Point, line and area contact geometries can be simulated. The load, in this case 100 N, is maintained at 50°C for 30 minutes. The oscillation frequency is 50Hz. The stroke, for measuring sliding friction, is 1mm. In the test, a 10 mm steel ball is oscillated under a specific load on a lapped steel disk lubricated with the grease or lubricant being tested until seizure occurs. At the conclusion of the time interval the bottom disk is cleaned with heptane and the wear scar is measured using a profilometer. Both scar depth and width measurements are recorded as an indication of the wear that occurred during the test. From these, the coefficient of friction can be calculated. TABLE 3

Optimal SRV Friction & Wear Test

(100N, lmm stroke, 50 Hz, 50°C and 30 min.)

Coefficient of Item Friction

Base grease (paraffinic-naphthenic mineral oils plus a lithium thickener made from a blend of 12-hydroxy and tallow fatty acids) 0.120 Plus 6% Example 3 0.095

Plus 6% Example 6 0.088

Plus 3% Example 3 0.070

Plus 3% Example 6 0.074

Plus 1.5% Example 3 0.085 Plus 1.5% Example 6 0.060

Plus 6% Example 1 0.070

Plus 6% Example 4 0.072

Plus 6% Example 7 0.068

Plus 1.5% Example 1 0.095 Plus 1.5% Example 4 0.052

The product of each example demonstrated a lower coefficient of friction than that of the base grease. There was a tendency, however, for the coefficient of friction to be lower in the examples where blending had occurred at an elevated temperature (apparently in which a reaction had occurred)than in the examples where the components had merely been mixed.

Claims

CLAIMS I

1. A reaction product for simultaneously enhancing the antiwear and friction reducing properties of lubricants or greases, which product comprises reacting (1) at least one metallic dithiocarbamate and (2) at least one metallic dithiophosphate at a temperature of from 70° and 100°C.

2. A pre-blended composition for simultaneously enhancing the antiwear and friction reducing properties of lubricants or greases, which composition is made by mixing (1) at least one metallic dithiocarbamate with (2) at least one metallic dithiophosphate.

3. The product or composition of ciaim 1 or 2, wherein the metal of the metallic dithiocarbamate is selected from zinc, nickel, antimony, copper, cobalt, iron, cadmium, manganese, sodium, magnesium, calcium and lead.

4. The product or composition of claim 1 or 2, wherein the metallic dithiophosphate is selected from zinc or molybdenum dialkyl dithiophosphate.

5. The product or composition of claim 1 or 2, wherein the metal of the metallic dithiocarbamate and the metal of the metallic dithiophosphate are two different metals.

6. The product or composition of claim 1 or 2, wherein the alkyl group of the dialkyl dithiocarbamate has a length from 2 to 30 carbon atoms.

7. The product or composition of claim 1 or 2, wherein the metallic dithiocarbamate is antimony diamyl dithiocarbamate and the metallic dithiophosphate is molybdenum di-2-ethylhexyl dithiophosphate.

8. A lubricant composition comprising a lubricating oil or a grease prepared therefrom and an effective amount of the product of claim 1.

9. A lubricant composition comprising a lubricating oil or a grease prepared therefrom and an effective amount of the pre-blended composition of claim 2.

10. The product of claim 1, wherein the metallic dithiocarbamate and metallic dithiophosphate are reacted in a ratio of from 1:9 to 9:1.

11. The composition of claim 2, wherein the metallic dithiocarbamate and metallic dithiophosphate are mixed in a ratio of from 1:9 to 9:1.

12. The lubricant composition of claim 8, wherein the reaction product is present in an amount from 0.01 wt% to 10 wt%.

13. The lubricant composition of claim 9, wherein the pre¬ blended combination is present in an amount from 0.01 wt% to 10 wt%.

14. The pre-blended combination of claim 2, wherein the blending occurs in the temperature range between -20"C and 70°C.

15. A process for the production of a lubricant additive possessing the synergism of enhanced antiwear and antifunctional properties, wherein one metallic dithiocarbamate and one metallic dithiophosphate are reacted at atmospheric pressure in a temperature range from 70°C to 100°C.

16. A process for the production of a lubricant additive possessing the synergism of enhanced antiwear and antifunctional properties, wherein one metallic dithiocarbamate and one metallic dithiophosphate are blended at atmospheric pressure in a temperature range from -20°C to 70°C.

17. A process for simultaneously enhancing the antiwear and friction reducing properties of lubricants or greases which comprises adding to the lubricants or greases an effective amount of the product of claim 1.

18. A process for simultaneously enhancing the antiwear and friction reducing properties of lubricants or greases which comprises adding to the lubricants or greases an effective amount of the product of claim 2.