RU2266912C2 - Organomolybdenum complexes, addition agent for lubricant material, method for reducing friction coefficient - Google Patents

Abstract

FIELD: chemistry of organometallic compounds, lubricants.

SUBSTANCE: invention relates to organomolybdenum complexes of the general formula (I): (Z-N=)₂Mo(S₂CNR₂)₂ (I) wherein Z and R mean independently (C₁-C₁₀)-branched alkyl. Compounds are useful as friction modifying agents in lubricant materials being especially in lubricant oils.

EFFECT: valuable properties of complexes.

10 cl, 3 tbl, 8 ex

Description

BACKGROUND OF THE INVENTION

Field of Invention

It is well known that molybdenum compounds added to lubricating oils, depending on their structure, can play a significant role both as friction modifiers and as antiwear additives. The present invention relates to lubricant additives and lubricant compositions, and more particularly to a new class of molybdenum-based friction modifying additives derived from organo-imidomolybdenum complexes that can be incorporated into lubricating oils. The purpose of the present invention is to provide additives that can reduce friction and ease the task for specialists making up engine oil compositions in terms of meeting new requirements for engine oils for passenger cars, such as ILSAC GF-3.

Description of the prior art

Regulators today are looking for ways to make more efficient use of fuel in automobiles using legislation (CAFE requirements), which places the responsibility for achieving such savings on car manufacturers, which in turn transfer at least some of this responsibility to manufacturers of lubricating oils, releasing engine oil specifications. As fuel economy requirements become more and more stringent, the inclusion of additives to modify friction in lubricant compositions is becoming more and more important. It is well known that the fuel efficiency of motor oils can be improved by the use of friction-reducing additives. It is also understood that, for maximum effectiveness, such additives should be active at engine operating temperature.

In addition, zinc dialkyl dithiophosphates (ZDDP) have been used as antiwear and antioxidant additives in lubricating oil compositions (composite oils) for over 50 years. However, zinc dialkyldithiophosphates cause ash formation, which increases the particulate matter content of automobile exhausts. State regulatory authorities are looking for ways to reduce emissions in the atmosphere of zinc. Moreover, it is believed that phosphorus present in dialkyldithiophosphates also limits the life of the catalytic converters used in automobiles to reduce pollution. For reasons of toxicity and from an environmental point of view, it is very important to limit the formation of particulate matter and contaminants during engine operation, but it is also important to prevent the reduction of antiwear characteristics of lubricating oils. Given the above disadvantages of the known zinc and phosphorus additives, the next objective of the present invention is the provision of antiwear additives that do not contain either zinc or phosphorus.

In the field of lubricating oil development, many attempts have been made to provide additives that provide anti-friction or oily properties. It is known that molybdenum compounds are useful as friction modifiers and antioxidants and are able to provide anti-wear properties and resistance to ultra-high pressure in lubricating oil compositions.

Thiocarbamate additives for lubricating oils, in particular molybdenum-containing thiocarbamates, have been disclosed in the patent literature.

US patent No. 3419589 discloses a method for producing molybdenum (VI) complexes of dialkyldithiocarbamate and their sulfonated derivatives in high yields by acidifying alkaline dialkyl dithiocarbamates and alkaline molybdates with diluted nitric acid and their subsequent treatment with hydrogen sulfide to form sulfonated derivatives of the reaction product. It is indicated that these compounds are useful as additives for lubricants.

US patent No. 3509051 discloses lubricating oils and greases, which, as indicated therein, exhibit excellent ultrahigh pressure resistance, antioxidant and antiwear properties when they contain sulfonated oxymolybdendethiocarbamates of the general formula:

[R ₂ N-CS-S-] ₂ Mo ₂ O _m S _n ,

where m + n = 4, m has a value in the range of 2.35 to 3, n has a value in the range of 1.65 to 1, and R is a hydrocarbon group containing 1-24 carbon atoms.

US patent No. 3541014 discloses lubricant compositions which, as indicated therein, exhibit improved ultrahigh pressure resistance and antiwear properties and are distinguished by the presence of molybdenum-containing organic complexes soluble in oil. Such complexes are obtained by contacting molybdenum-containing anions with oil-soluble, highly alkaline, group II metal-containing compositions until some of the anions react with the metal of group II. Lubricating oils, cutting fluids, greases, etc. are illustrative examples of the lubricant compositions disclosed herein.

US patent No. 4098705 discloses a compound of the formula:

where R ₁ and R ₂ represent a hydrocarbon group containing 1-24 carbon atoms, and x has a value of 0.5-2.3, which, as indicated, is useful as an additive for a lubricant.

US Pat. No. 4,164,473 discloses hydrocarbon-soluble organomolybdenum complexes obtained as a reaction product of a hydrocarbon-substituted hydroxyalkylated amine, for example N, N ', N'-Tris (2-hydroxyethyl) -n-tallow-1,3-diaminopropane, with about one molar equivalent molybdenum compounds, for example ammonium molybdate, which, as indicated, are useful hydrocarbon additives, in particular in combination with an oil soluble sulfur donor, for example metal dialkyldithiophosphonate, to provide a combination of additives with lubricating oils. Lubricant compositions comprising such shared additives are disclosed as exhibiting improved anti-friction and anti-wear properties.

US patent No. 4259194 discloses antioxidant additives for lubricating oils, which are obtained by combining ammonium tetratiomolybdate and a complex of basic nitrogen compounds to obtain a composition containing sulfur and molybdenum.

US patent No. 4259195 discloses antioxidant additives for lubricating oil, which are obtained by combining a polar promoter, an acid molybdenum compound and some basic nitrogen compounds to obtain a molybdenum-containing composition.

US patent No. 4263152 discloses the preparation of antioxidant additives for lubricating oil by combining water, an acid molybdenum compound, a complex of a basic nitrogen compound and a sulfur source to produce a composition containing sulfur and molybdenum.

US patent No. 4265773 discloses antioxidant additives for lubricating oil, which are obtained by combining an acid molybdenum compound, an oil soluble basic nitrogen compound and carbon disulfide to obtain a composition containing sulfur and molybdenum.

US patent No. 4266945 discloses the preparation of molybdenum-containing compositions by reacting an acid molybdenum compound or its salt or its condensation product with phenol or aldehyde and a primary or secondary amine. Preferred amines are diamines, such as oleyl substituted trimethylenediamine, and their formaldehyde condensation products. An optional but preferred ingredient in the reaction mixture is at least one oil soluble dispersant. Molybdenum-containing compositions are indicated to be useful as additives to fuels and lubricants, especially lubricants, when combined with active sulfur compounds.

US patent No. 4272387 discloses antioxidant additives for lubricating oil, which are obtained by combining an acid molybdenum compound, a complex of basic nitrogen compounds and a sulfur source to obtain a composition containing sulfur and molybdenum.

US patent No. 4283295 discloses antioxidant additives for lubricating oil, which are obtained by combining a polar promoter, ammonium tetratiomolybdate and a complex of basic nitrogen compounds to obtain a composition containing sulfur and molybdenum.

US patent No. 4285822 discloses antioxidant additives for lubricating oil, which are obtained by (1) combining a polar solvent, an acid molybdenum compound and an oil soluble basic nitrogen compound to obtain a molybdenum complex and (2) contacting the complex with carbon disulfide to obtain a composition, containing sulfur and molybdenum.

US patent No. 4289635 discloses compositions containing molybdenum, which are obtained by the interaction of an olefinically unsaturated compound capable of interacting with active sulfur, with a composition obtained by the interaction:

(a) a phosphorus-containing acid of the formula:

where each X and X 'independently represents oxygen or sulfur, each n has a value of 0 or 1, and each R independently represents a hydrocarbon-based radical that is the same or different from each other; and

(b) at least one hexavalent molybdenum compound and

(c) hydrogen sulfide, in the presence of (d) a polar solvent. It is indicated that such compositions are useful as additives for lubricants and that when used as lubricants for internal combustion engines, they obtain better fuel economy.

US patent No. 4315826 discloses multi-purpose additives for lubricants, which are obtained by the interaction of carbon disulfide with thiomolybdenum derivatives of polyalkenylsuccinimides containing basic nitrogen functional groups. It is indicated that such additives act as dispersants, while possessing excellent antifriction properties, and provide anti-wear and antioxidant properties to the lubricant.

US patent No. 4369119 discloses antioxidant additives for lubricating oil, which are obtained by combining (a) a sulfur-containing molybdenum compound obtained by reacting an acid molybdenum compound, a basic nitrogen compound and a sulfur compound with (b) an organic sulfur compound.

US patent No. 4370246 discloses the preparation of a combination of antioxidant additives for lubricating oils by combining (a) a sulfur-containing molybdenum compound obtained by reacting an acid molybdenum compound, a basic nitrogen compound and a sulfur compound with (b) an aromatic amine compound.

US Patent No. 4,395,343 discloses the preparation of antioxidant additives for lubricating oils by combining (a) a sulfur-containing molybdenum compound obtained by reacting an acid molybdenum compound, a basic nitrogen compound and carbon disulfide with (b) a sulfur-containing organic compound.

U.S. Patent No. 4,402,840 discloses the production of antioxidant additives for lubricating oils by combining (a) a sulfur-containing molybdenum compound obtained by reacting a compound of ammonium thiolybdate, a basic nitrogen compound with (b) a sulfur-containing organic compound.

US Patent No. 4,428,848 discloses compounds prepared by reacting an adduct of phosphorus sulfonated polyisoalkylene or alpha olefin and an acidified salt of hexavalent molybdenum, which, as indicated, when incorporated into lubricants, provide improved protection against copper corrosion compared with non-molybdenum-treated adducts. A combination of such compounds with zinc dialkyldithiophosphate is also disclosed, and this combination provides much better oxidation inhibition in lubricants, as indicated in this patent, than is obtained using only zinc dialkyldithiophosphate or only a molybdenum adduct.

US patent No. 4474673 discloses anti-friction additives for lubricating oils obtained by the interaction of a sulfonated organic compound containing active hydrogen or potentially active hydrogen, and molybdenum halide.

US Patent No. 4,479,883 discloses a lubricating oil composition which, as indicated, has particularly good friction-reducing properties and includes a polycarboxylic acid ester with glycol or glycerin and a selected metal dithiocarbamate and which contains a relatively low amount of phosphorus.

US Pat. No. 4,501,678 discloses a lubricant containing molybdenum dialkyldithiocarbamates, which, as indicated, is useful for improving an indicator such as fatigue life of transmission mechanisms.

US Patent No. 4,765,918 discloses a lubricating oil additive obtained by reacting a triglyceride with a basic nitrogen compound to produce a reaction product, reacting this reaction product with an acid molybdenum compound to produce an intermediate reaction product, and reacting an intermediate reaction product with a sulfur-containing compound.

US patent No. 4889647 discloses molybdenum complexes obtained by the interaction of (a) fatty oil, (b) diethanolamine and (c) a molybdenum source. It is indicated that the complexes give anti-friction and anti-wear properties to lubricating compositions and reduce fuel consumption in internal combustion engines.

US patent No. 4995996 discloses a lubricating composition comprising a large amount of oil with a viscosity for lubrication and a small amount of additives having the formula Mo ₂ L ₄ , where L is a ligand selected from xanthates and mixtures thereof and, in particular, xanthates containing a sufficient number of atoms carbon to make the oil soluble. Typically, xanthate ligand L contains from about 2 to 30 carbon atoms.

US patent No. 5605880 discloses a lubricating oil composition, which is obtained by content in (A) base oil, in which the content of aromatic components is 3.0% wt. or less, N is 50 ppm by mass or less, S is 50 ppm by mass, and the viscosity is 2.0-50.0 mm ² / s based on the total weight of the composition, (B) 0.05 -2.0% wt. alkyl diphenylamine (s) and / or phenyl-α-naphthylamine (s) and (C) MoDTC C _8-23 and / or C _3-18 in an amount of 50-2000 ppm by weight, based on the amount of molybdenum. Such a lubricating oil composition, as indicated, has high heat-resistant characteristics, high oxidation resistance and improved friction characteristics, and it is particularly suitable as a lubricating oil for internal combustion engines.

US Patent No. 5,650,381 discloses a lubricating oil composition that contains from about 100 to 450 ppm of molybdenum from a molybdenum compound substantially free of active sulfur and from about 750 to 5,000 ppm of secondary diarylamine. Such a combination of components, as indicated, provides lubricant oil with improved oxidation control and friction modifier performance. This composition is particularly suitable for use as a crankcase lubricant (See also U.K. 2307245).

US patent No. 5688748 discloses a lubricating oil composition for internal combustion engines, which, as indicated, has a high oxidation stability by nitrogen oxides, excellent friction characteristics, stored over a long period of time, and the ability to reduce fuel consumption over time. The lubricating oil composition consists of a base oil, mainly consisting of hydrocarbon oil, having a dynamic viscosity of 2-20 mm ² / s at 100 ° C, and contains a total amount of aromatic components of 3% wt. or less, the total number of one and two-ring naphthenes 45% wt. or more, 50 ppm (by weight) or less sulfur and 50 ppm (by weight) or less nitrogen, to which, based on the total weight of the composition, is added as a source of molybdenum 0.02-0.2% wt. molybdenum dithiocarbamate, as a source of phosphorus 0.02-0.15% wt. zinc dithiophosphate and 0.05-3% wt. phenol based antioxidant. It is indicated that the lubricating oil composition has a low coefficient of friction, which remains for a long time even after oxidation with nitrogen oxides.

US Patent No. 5,840,672 discloses antioxidant compositions comprising (A) at least one secondary diarylamine, (B) at least one sulfonated olefin and / or sulfonated hindered phenol, and (C) at least one oil soluble molybdenum compound . Such antioxidant compositions are indicated to be highly effective in providing oxidation resistance to lubricating compositions, especially for highly saturated, low sulfur lubricant base oils.

US patent No. 6103674 discloses an additive for lubricating oil, including the reaction product:

(a) an unsaturated or saturated ester or acid,

(b) a diamine of the formula:

(c) carbon disulfide; and

(d) molybdenum compounds,

where R ₈ represents an alkyl group containing 1-40 carbon atoms, R ₉ and R ₁₀ represent independently selected aliphatic or aromatic groups, W represents oxygen, sulfur or —CH ₂ -. This additive gives the lubricating oil the properties of friction modification and beneficial anti-wear characteristics, characteristics of resistance to ultra-high pressure and resistance to oxidation.

US patent No. 6117826 discloses dithiocarbamyl derivatives, which are useful as multifunctional additives for lubricating oils.

EP 719313 B1 widely claims (C _7-24 ) molybdenum dialkylthiocarbamates and alkylated diphenylamines in lubricating oils.

The disclosures of the above referenced documents are incorporated herein by reference in their entirety.

SUMMARY OF THE INVENTION

The present invention provides an additive to a lubricating oil based on a complex of organo-imidomolybdenum, which imparts friction modification properties to the lubricating oil.

More specifically, the present invention relates to a composition of a substance containing a compound of the formula

where Z and R are independently selected from the group consisting of linear hydrocarbon groups, branched hydrocarbon groups, cyclic hydrocarbon groups, and mixtures thereof.

In another embodiment, the present invention relates to a lubricant additive containing a compound of the formula

where Z and R are independently selected from the group consisting of linear hydrocarbon groups, branched hydrocarbon groups, cyclic hydrocarbon groups, and mixtures thereof.

In yet another embodiment, the present invention is directed to a method of reducing the friction coefficient of a lubricant, comprising adding a compound of the formula to said lubricant

where Z and R are independently selected from the group consisting of linear hydrocarbon groups, branched hydrocarbon groups, cyclic hydrocarbon groups, and mixtures thereof.

DESCRIPTION OF PREFERRED EMBODIMENTS

As indicated above, the present invention is directed to the composition of a substance useful as a friction modifying additive for lubricants, especially lubricating oils. The composition is a compound of the formula

where Z and R are independently selected from the group consisting of linear hydrocarbon groups, branched hydrocarbon groups, cyclic hydrocarbon groups, and mixtures thereof.

These hydrocarbon groups preferably contain from 1 to about 44 carbon atoms, more preferably from 1 to about 22 carbon atoms. Hydrocarbon groups may be fully saturated or partially unsaturated and may represent either straight chain or branched chain groups, or they may be cyclic. Thus, R and Z can, for example, independently be methyl, ethyl, propyl, butyl, tert-butyl, pentyl, hexyl, 2-ethylhexyl, heptyl, octyl, isooctyl, tert-octyl, nonyl, decyl, undecyl, dodecyl , tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, oleyl, nonadecyl, eicosyl, geneycosyl, docosyl, tricosyl, tetracosyl, pentacosyl, triacontyl, pentatriacontyl, tetraconylcyl cyclyl, cyclopyl, cyclopentyl, cyclopentyl, cyclopentyl, cyclopentyl, cyclopentyl, cyclopentyl, cyclopentyl and their isomers and mixtures thereof. In addition, the R and / or Z chains may contain ester groups or heteroatoms, such as oxygen and sulfur atoms, which may take the form of ethers, polyesters and / or sulfides.

Additives of the present invention can be obtained by the following synthesis scheme:

(ZN =) ₂ MoCl ₂ * DME + 2LiS ₂ CNR ₂ → (ZN =) ₂ Mo (S ₂ CNR ₂ ) ₂ + 2LiCl + DME

where Z and R are independently selected from the group consisting of linear hydrocarbon groups, branched hydrocarbon groups, and mixtures thereof.

The starting material (ZN =) ₂ MoCl ₂ * DME can be prepared by reacting linear and / or branched alkyl amines with Na ₂ MoO ₄ + DME (dimethoxyethane) + trimethylsilyl chloride.

LiS ₂ CNR ₂ can be obtained by reacting butyllithium with a secondary amine, followed by reacting with carbon disulfide. For instance,

The additives of the present invention can be used with or without other friction modifiers, as a partial or complete replacement for the additives currently used. They can also be used in combination with other additives typically found in motor oils, as well as other ashless antiwear additives and other antioxidants. Typical additives present in lubricating oils are dispersants, detergents, corrosion / rust inhibitors, antioxidants, for example, secondary amine based antioxidants, hindered phenol antioxidants, sulfur containing hindered phenol antioxidants, sulfonated olefins, thiadiazoles, metal deactivators, anti-wear additives, for example, zinc dialkyldithiophosphates, antifoam additives, friction modifiers, compaction swelling agents, demulsifiers, additives, ponies digits together with the viscosity index ( "VI" additive), and pour point depressants, pour point depressants. See, for example, US Pat. No. 5,498,809, incorporated herein by reference, for a description of useful lubricant additive compositions.

Examples of dispersants include polyisobutylene succinimides, succinic acid and polyisobutylene esters, ashless dispersants, which are Mannich bases, and the like. Examples of detergents include metal phenates, metal sulfonates, metal salicylates, metal calixarenes, and the like. Examples of friction modifiers that can be used in combination with the friction modifiers of the present invention include fatty acid esters and amides, glycerol monooleate, organomolybdenum compounds, molybdenum dialkyl dithiocarbamates, molybdenum dialkyl dithiophosphates and the like. An example of an anti-foam additive is polysiloxane and the like. An example of a corrosion inhibitor (rust) is polyoxyalkylene polyols and the like. Examples of temperature viscosity reducing additives are olefin copolymers and dispersing olefin copolymers and the like. An example of a pour point depressant is poly (methyl methacrylate) and the like.

Examples of antioxidant additives that can be used in combination with the additives of the present invention include alkylated diphenylamines and N-alkylated phenylenediamines. Secondary diarylamines are well known antioxidants, and there is no particular restriction on the type of secondary diarylamine that can be used in the practical embodiment of the present invention. A secondary diarylamine type antioxidant in lubricating oil provides a synergistic mixture of antioxidants with the additive of the present invention. Preferably, the secondary diarylamine type antioxidant has the general formula R ₁₁ —NH — R ₁₂ , wherein R ₁₁ and R ₁₂ each independently represent a substituted or unsubstituted aryl group containing 6-46 carbon atoms. Examples of substituents for the aryl group are aliphatic hydrocarbon groups, such as alkyl containing 1-40 carbon atoms, hydroxyl, carboxyl, amino, N-alkylated amino, N ', N-dialkylated amino, nitro or cyano. Aryl is preferably substituted or unsubstituted phenyl or naphthyl, especially when one or both aryl groups are substituted with alkyl, such as alkyl containing 4-24 carbon atoms. Preferred alkylated diphenylamines that may be used in the practice of the present invention include nonylated diphenylamine, octylated diphenylamine (e.g. di (octylphenyl) amine), styrene substituted diphenylamine, octylated styrene substituted diphenylamine and butylated octylated diphenylamine.

An alkyl group containing from 1 to 40 carbon atoms can have either a straight or branched chain, which can be either a fully saturated or partially unsaturated hydrocarbon chain, for example methyl, ethyl, propyl, butyl, pentyl, hexyl, 2-ethylhexyl , heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, oleyl, nonadecyl, eicosyl, geneukosyl, docosyl, tricosyl, tetraconcilon, tetraconcil, tetraconyl, tetraconyl, tetraconyl, tetraconyl, tetraconyl, tetraconyl, tetraconcil, . and their isomers and mixtures thereof.

Examples of some secondary diarylamines that can be used in the practice of the present invention include diphenylamine, dialkylated diphenylamine, trialkylated diphenylamine or mixtures thereof, 3-hydroxydiphenylamine, 4-hydroxydiphenylamine, N-phenyl-1,2-phenylenediamine, N-phenyl-1, 4-phenylenediamine, mono- and / or dibutyl diphenylamine, mono- and / or dioctyldiphenylamine, mono- and / or dinonyldiphenylamine, phenyl-α-naphthylamine, phenyl-β-naphthylamine, diheptyl diphenylamine, mono and / or di (α-methylstyryl diphenylamine, mono- and / or distyryldiphenyl min, N, N'-diisopropyl-p-phenylenediamine, N, N'-bis (1,4-dimethylpentyl) -p-phenylenediamine, N, N'-bis (1-ethyl-3-methylpentyl) -p-phenylenediamine , N, N'-bis (1-methylpentyl) -p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N, N'-di- (naphthyl-2 -) - p-phenylenediamine, N-isopropyl- N'-p-phenylenediamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N- (1-methylpentyl) -N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'- phenyl-p-phenylenediamine, 4- (p-toluenesulfonamido) diphenylamine, 4-isopropoxydiphenylamine, tert-octylated N-phenyl-1-naphthylamino and mixtures of mono- and dialkylated tert-butyl-tert-octyl diphenylamines.

Another example of the types of antioxidants that can be used in combination with the additives of the present invention are hindered phenols. Examples of oil soluble phenolic compounds include alkylated monophenols, alkylated hydroquinones, hydroxylated thiodiphenyl ethers, alkylidenebis phenols, benzyl compounds, acylaminophenols and esters and amides of hindered phenol substituted alkanoic acids. In a preferred embodiment, the lubricant compositions include 3,5-di-tert-butyl-4-hydroxy-hydrocinnamic acid, branched C ₇ -C ₉ 2,6-di-tert-butyl-p-cresol alkyl ester and their mixtures.

Another example of the type of antioxidant that can be used in combination with the additives of the present invention are oil soluble copper compounds and the like.

Examples of antiwear additives that can be used in combination with the additives of the present invention include organoborates, organophosphites, organic sulfur compounds, zinc dialkyldithiophosphates, zinc diaryldithiophosphates, phosphosulfonated hydrocarbon, and the like.

Suitable phosphates for use as antiwear agents include dihydrocarbon dithiophosphates in which hydrocarbon groups contain an average of at least three carbon atoms. Particularly useful are metal salts of at least one dihydrocarbon dithiophosphoric acid, where the hydrocarbon groups contain an average of at least three carbon atoms. Acids from which dihydrocarbon dithiophosphates can be obtained can be represented by acids of the formula

where R ₁₆ and R ₁₇ are the same or different alkyl, cycloalkyl, aralkyl, alkaryl groups or derivatives of substituted essentially hydrocarbon radicals or any of the above groups and where each of the groups R ₁₆ and R _{17 of the} acid compound contains on average at least at least three carbon atoms. By the term “substantially hydrocarbon” is meant radicals containing substituent groups (for example, one to four substituent groups per radical group), such as ether, ester, nitro or halogen, which do not significantly affect the hydrocarbon nature of the radical.

Specific examples of suitable R ₁₆ and R ₁₇ radicals include radicals such as isopropyl, isobutyl, n-butyl, sec-butyl, n-hexyl, heptyl, 2-ethylhexyl, diisobutyl, isooctyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, butylphenyl, o, p-dipentylphenyl, octylphenyl, polyisobutene- (molecular weight 350) -substituted phenyl, tetrapropylene-substituted phenyl, β-octylbutylnaphthyl, cyclopentyl, cyclohexyl, phenyl, chlorophenyl, o-dichlorophenyl, bromophenyl, benzyl, benzyl, phenyl, benzyl chlorobenzyl, chloropentyl, dichlorophenyl, nitrophenyl, dichlorodecyl, xenyl etc. Alkyl radicals containing from about 3 to about 30 carbon atoms, and aryl radicals containing from about 6 to about 30 carbon atoms, are preferred. Particularly preferred R ₁₆ and R ₁₇ radicals are alkyl radicals containing 4-18 carbon atoms.

Phosphorodithic acids can easily be prepared by reacting phosphorus pentasulfide and an alcohol or phenol. Such a reaction involves mixing at a temperature of from about 20 ° C. to about 200 ° C. four moles of alcohol or phenol with one mole of phosphorus pentasulfide. As the reaction progresses, hydrogen sulfide is released. You can use a mixture of alcohols, phenols, or both, for example a mixture of C ₃ -C ₃₀ alcohols, aromatic C ₆ -C ₃₀ alcohols, etc.

Metals that can be used to produce phosphate salts include Group I metals, Group II metals, aluminum, lead, tin, molybdenum, manganese, cobalt and nickel. The preferred metal is zinc. Examples of metal compounds that can interact with an acid include lithium oxide, lithium hydroxide, lithium carbonate, lithium pentylate, sodium oxide, sodium hydroxide, sodium carbonate, sodium methylate, sodium propylate, sodium phenoxide, potassium oxide, potassium hydroxide, potassium carbonate, potassium methylate, silver oxide, silver carbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium ethylate, magnesium propylate, magnesium phenoxide, calcium oxide, calcium hydroxide, calcium carbonate, calcium methylate, calcium propylate, calcium pentylate, qi nca, zinc hydroxide, zinc carbonate, zinc propylate, strontium oxide, strontium hydroxide, cadmium oxide, cadmium hydroxide, cadmium carbonate, cadmium ethylate, barium oxide, barium hydroxide, barium hydrate, barium carbonate, barium ethylate, barium pentylate, aluminum oxide, aluminum propylate, lead oxide, lead hydroxide, lead carbonate, tin oxide, tin butylate, cobalt oxide, cobalt hydroxide, cobalt carbonate, cobalt pentylate, nickel oxide, nickel hydroxide, nickel carbonate, and the like.

In some cases, the introduction of certain ingredients, in particular carboxylic acids or metal carboxylates, for example small amounts of metal acetate or acetic acid, used in combination with a metal reagent, promotes the interaction and results in an improved product. For example, the use of up to about five percent zinc acetate in combination with the required amount of zinc oxide promotes the formation of zinc phosphordithioate.

The preparation of metal phosphordithioates is well known in the art and is described in many published patents, including US Pat. Nos. 3,293,181, 3,391,745, 3,396,109 and 3,442,804, the disclosures of which are incorporated herein by reference in their entirety.

Also useful as anti-wear additives are amine derivatives of dithiophosphoric acid compounds, such as those disclosed in US Pat. No. 3,637,499, the disclosure of which is incorporated herein by reference in its entirety.

Zinc salts are most often used as antiwear additives in lubricating oils in an amount of from 0.1 to 10, preferably from 0.2 to 2 weight percent, based on the total weight of the lubricating oil composition. They can be prepared according to known methods by first producing dithiophosphoric acid, usually by reacting an alcohol or phenol with P ₂ S ₅ , and then neutralizing the dithiophosphoric acid with a suitable zinc compound.

Mixtures of alcohols can be used, including mixtures of primary and secondary alcohols, while secondary alcohols are usually used to give improved anti-wear properties, and primary alcohols for heat resistance. Mixtures of these two alcohols are particularly suitable. As a rule, any basic or neutral zinc compound can be used, but oxides, hydroxides and carbonates are most often used. Commercial additives often contain excess zinc due to the use of an excess amount of the basic zinc compound in the neutralization reaction.

Zinc dihydrocarbon dithiophosphates (ZDDP) are oil-soluble salts of dithiophosphoric acid dihydrocarbon esters and can be represented by the formula

where R ₁₆ and R _{17 are} defined above in the description of the previous formula. When additional additives are used in the practice of the present invention, it is particularly preferred that they are selected from the group consisting of zinc dialkyldithiophosphates, zinc diaryldithiophosphates, alkyl diphenylamines, hindered alkyl phenols, and mixtures thereof.

When the compositions contain such additives, they are usually mixed with the base oil in amounts effective to provide their usual concomitant function. Representative effective amounts of such additives are presented below:

Songs Wide wt.% Preferred wt.% "VI" additive 1-12 1-4 Corrosion inhibitor 0.01-3 0.01-1.5 Oxidation inhibitor 0.01-5 0.01-1.5 Dispersant 0,1-10 0.1-5 Lubricating oil fluidity improver 0.01-2 0.01-1.5 Detergents / Corrosion Inhibitors (Rust) 0.01-6 0.01-3 Depressant additive to lower pour point 0.01-1.5 0.01-0.5 Antifoam additives 0.001-0.1 0.001-0.01 Antiwear additives 0.001-5 0.001-1.5 Compaction Swelling Agent 0.1-8 0.1-4 Friction modifiers 0.01-3 0.01-1.5 Base lubricating oil Balance Balance

When using other additives, it may be desirable, although not necessary, to obtain the additive concentrates, including the concentrated solutions or dispersions of the additives of the present invention (present in the concentrate in the amounts indicated above), together with one or more other additives (the concentrate forming the mixture of additives, hereinafter referred to as a complex of additives), whereby several additives can be simultaneously added to the base oil to obtain a lubricating oil composition. The dissolution of the additive concentrate in lubricating oil can be facilitated by the use of solvents and by mixing, followed by moderate heating, but this is not essential. The concentrate or additive complex is typically formulated to contain additives in an amount suitable to provide the desired concentration in the final composition when the additive complex is combined with a predetermined amount of base lubricant. Thus, the additives of the present invention can be added to small amounts of base oil or other compatible solvents along with other desired additives to form additive complexes containing the active ingredients, in total amounts typically from about 2.5 to about 90 percent, and preferably from about 15 to about 75 percent, and most preferably from about 25 to about 60 percent by weight of additives in suitable proportions, the rest being base oil. The final composition may include, as a rule, from about 1 to 20 weight percent of the additive complex, the rest being base oil.

All mass percentages indicated in this description (unless otherwise indicated) are based on the content of the active ingredient (AI) of the additive and / or based on the total weight of any complex of additives or compositions, which is the sum of the mass of the AI of each additive and mass of total oil or diluent.

Typically, the lubricant compositions of the present invention contain additives in a concentration ranging from about 0.05 to about 30 weight percent. Preferred are the concentration ranges of the additives from about 0.1 to about 10 weight percent, based on the total weight of the oil composition. Preferred concentration limits are from about 0.2 to about 5 weight percent. Additive oil concentrates may contain from about 1 to about 75 weight percent of the additive reaction product in an oil carrier or diluent with a lubricant viscosity.

In general, the additives of the present invention can be used in various base components of lubricating oils. A lubricating oil base component is any fraction of a natural or synthetic product that is a feed for a lubricating oil base component having a kinematic viscosity at 100 ° C. of from about 2 to about 200 cSt, more preferably from about 3 to about 150 cSt, most preferably from about 3 to about 100 cSt The basic component of lubricating oil can be obtained from natural lubricating oils, synthetic lubricating oils or mixtures thereof. Suitable base components of lubricating oils include base components obtained by isomerization of synthetic wax and paraffin, as well as base components that are hydrocracked products obtained by hydrocracking (rather than solvent extraction) of aromatic and polar components of the feedstock. Natural lubricating oils include animal oils, vegetable oils (e.g., rapeseed oil, castor oil and lard), petroleum oils, mineral oils, and oils derived from coal and shale.

Synthetic oils include hydrocarbon oils and halogen-substituted hydrocarbon oils such as polymerized and copolymerized olefins, alkylbenzenes, polyphenyls, alkylated diphenylethers, alkylated diphenyl sulfides, as well as their derivatives, analogs and homologs, and the like. Synthetic lubricating oils also include polymers and copolymers of alkylene oxide and their derivatives, where the terminal hydroxyl groups are modified by esterification, esterification, etc. Another suitable class of synthetic lubricants includes dicarboxylic acid esters with various alcohols. Esters useful as synthetic oils also include esters derived from C ₅ -C ₁₂ monocarboxylic acids and polyols and polyol ethers.

Silicone oils (such as polyalkyl, polyaryl, polyalkoxy or polyaryloxy siloxane oils or silicate oils) are another useful class of synthetic lubricating oils. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids, polymeric tetrahydrofurans, polyalphaolefins, and the like.

Lubricating oil can be obtained from crude, refined and refined oils or mixtures thereof. Crude oils are obtained directly from a natural source or synthetic source (e.g. coal, shale or tar and bitumen) without further purification or processing. Examples of crude oils include shale oil obtained directly by direct distillation, petroleum oil obtained directly from distillation, or ester oil obtained directly from the esterification process, each of which is then used without further processing. Refined oils are similar to crude oils, except that the refined oils have been subjected to one or more purification steps to improve one or more properties. Suitable purification methods include distillation, hydrotreating, dewaxing, solvent extraction, acid or base extraction, filtration and percolation, all of which are known to those skilled in the art. Re-refined oils are obtained by treating refined oils with methods similar to those used to produce refined oils. Such refined oils are also known as regenerated or refined oils, and are often further treated with methods to remove used additives and oil degradation products.

Can also be used the basic components of lubricating oils obtained in the process of hydroisomerization of paraffin, either separately or in combination with the above natural and / or synthetic base components. Such an oil, which is a product of paraffin isomerization, is obtained by hydroisomerization of natural or synthetic waxes or mixtures thereof over a hydroisomerization catalyst. Natural waxes are typically shale waxes obtained by dewaxing mineral oils with a solvent; Synthetic waxes are typically Fischer-Tropsch derived waxes. The resulting isomerization product (isomerate) is typically subjected to solvent dewaxing and fractionation to recover various fractions with certain viscosity limits. The product of isomerization of paraffins (paraffin isomerate) is also characterized by very high viscosity indices (VI), usually VI is at least 130, preferably at least 135 and higher, and after dewaxing, the pour point is about -20 ° C and higher.

The additives of the present invention are particularly useful as components in various lubricating oil compositions. Additives may be included in various lubricant viscosity oils, including natural and synthetic lubricating oils and mixtures thereof. Additives can be included in crankcase lubricants for internal combustion engines with spark ignition and compression ignition. The compositions can also be used in gas engine lubricants, turbine lubricants, automatic transmission fluids, gear lubricants, compressor lubricants, cutting fluids for metal cutting tools, hydraulic fluids and other lubricating oil and grease compositions. Additives can also be used in motor fuel compositions.

The advantages and features of the present invention will be more apparent from the examples below.

Example 1

Bis-tert-butylimidomolybdenum (VI) dichloride, DME adduct

All operations with molybdenum derivatives were carried out in an atmosphere of dry argon. Anhydrous Na ₂ MoO ₄ (30.9 g, 0.15 mol), absolute DME (0.5 L), triethylamine (84 ml, 0.6 mol), trimethylsilyl chloride (152 ml, 1.2 mol) and tert butylamine (31.3 ml, 0.3 mol) was mixed in a 1 L flask and refluxed for 12 hours. Na ₂ MoO _{4 was} completely dissolved. The reaction mixture was filtered and the solid (Et ₃ HN ⁺ Cl ^- ) was washed twice with DME and once with hot heptane. Solvents were removed in vacuo from the combined liquid phases and the resulting greenish solid mass was vigorously shaken with cold hexane. Hexane was filtered off to obtain 42.5 g (70%) of yellow crystals.

Example 2

Bis-tert-octylimidomolybdenum (VI) dichloride, DME adduct

All operations with molybdenum derivatives were carried out in an atmosphere of dry argon. MoO ₂ Cl ₂ DME (18 g, 0.0625 mol), tert-octylamine (20.1 ml, 0.125 mol), triethylamine (35 ml, 0.25 mol), trimethylsilyl chloride (31.6 ml, 0.25 mol) and DME (200 ml) were mixed together and refluxed for 5 hours. After cooling the solution to room temperature, the precipitate was filtered off, the solvent was evaporated under reduced pressure to 1/4 of its original volume, and was filtered again. Then, the remaining solvents were removed in vacuo to give a red oily product, which was recrystallized twice from pentane at -110 ° C. Received a red crystalline substance. The yield was 23 g (72%).

Example 3

Bis- (tert-butylimido) -bis- (diisooctyldithiocarbamato) molybdenum (VI)

C ₄₂ H ₈₆ MoN ₄ S ₄

All operations with molybdenum derivatives were carried out in an atmosphere of dry argon. To a solution of bis (isooctyl) amine (10.6 ml, 0.0351 mol) in diethyl ether (200 ml) at 0 ° C, a 1.48 M solution of butyl lithium in hexane (24 ml, 0.0351 mol) was carefully added with stirring ) After stirring the mixture for 10 minutes, CS ₂ (2.1 ml, 0.0351 mol) was carefully added and the temperature allowed to rise to 20 ° C. Then a solution of 7 g of the product of Example 1 (0.0175 mol) in 50 ml of DME was added, and after stirring for two hours, the solvents were evaporated under reduced pressure to a volume of 50 ml. 100 ml of n-hexane was added and the solution was filtered. The filtrate was evaporated in vacuo to give 15.5 g of a dark red oil.

Example 4

Bis (tert-octylimido) bis (diisooctyl dithiocarbamato) molybdenum (VI)

C ₅₀ H ₁₀₂ MoN ₄ S ₄

All operations with molybdenum derivatives were carried out in an atmosphere of dry argon. To a solution of bis- (isooctyl) amine (4.1 ml, 0.0137 mol) in 100 ml of diethyl ether at 0 ° C, a 1.48 M solution of butyl lithium in hexane (9.3 ml, 0.0137 mol) was carefully added with stirring ) After stirring the mixture for 10 minutes, CS ₂ (0.83 ml, 0.0137 mol) was carefully added and the temperature allowed to rise to 20 ° C. Then, a solution of 3.5 g of the product of Example 2 (0.00686 mol) in 30 ml of DME was added, and after stirring for 10 minutes, the solvents were evaporated under reduced pressure to a volume of 30 ml. 70 ml of n-hexane was added and the solution was filtered. The filtrate was evaporated in vacuo to give 7.2 g of a dark red oil.

Example 5

(tert-octyl N) ₂ Mo {S ₂ CN (Coco) ₂ } ₂

All operations with molybdenum derivatives were carried out in an atmosphere of dry argon. To a solution of 10 g of dicocoamine in 200 ml of diethyl ether at 0 ° C, a 1.58 M solution of butyllithium in hexane (15.3 ml, 0.0242 mol) was carefully added with stirring. After stirring the mixture for 15 minutes, 1.46 ml of CS ₂ (0.0242 mol) was carefully added and the temperature allowed to rise to 20 ° C. Then a solution of 6.18 g (0.0121 mol) of the product of Example 2 in 20.9 ml of DME was added, and after stirring for 2 hours, the solvents were evaporated under reduced pressure to a volume of 50 ml. 100 ml of n-hexane was added and the solution was filtered. The filtrate was evaporated in vacuo to give 16.8 g of a dark red oil.

Example 6

(tert-butylN) ₂ Mo {S ₂ CN (Coco) ₂ } ₂

All operations with molybdenum derivatives were carried out in an atmosphere of dry argon. To a solution of 10 g of dicocoamine in 200 ml of diethyl ether at 0 ° C, a 1.58 M solution of butyllithium in hexane (15.3 ml, 0.0242 mol) was carefully added with stirring. After stirring the mixture for 15 minutes, 1.46 ml of CS ₂ (0.0242 mol) was carefully added and the temperature allowed to rise to 20 ° C. Then, a 0.324 M solution of the product of Example 1 in DME (37.3 ml, 0.0121 mol) was added, and after stirring for 20 minutes, the solvents were evaporated under reduced pressure to a volume of 50 ml. 100 ml of n-hexane was added and the solution was filtered. The filtrate was evaporated in vacuo to give 13.6 g of a dark red oil.

Example 7

Friction Coefficient Testing Using Cameron-Plint TE77 High Frequency Friction Machine

The antifriction properties of the new reaction product in a fully formulated lubricating oil were determined in a Cameron-Plint TE77 friction test. Tested fully composed lubricating oils contained 1% wt. tested additives. Additives were tested for effectiveness in engine oil at increasing temperatures and compared with similar compositions with and without friction. In table 1, the digital indicators of the test results (coefficient of friction) decrease with increasing efficiency. In other words, the lower the coefficient of friction, the better the effect of the additive to reduce friction.

The test procedure for determining the coefficient of friction using a high-frequency friction machine Cameron-Plint TE77 is as follows. 10 ml of a sample of the oil containing the additive was placed in the test chamber in such a way as to cover the flat stationary hardened NSOH B01 graduated plate used for testing (RC 60 / 0.4 microns). A reciprocating sample, a mounting pin made of nitrided steel 16 mm long (diameter 6 mm, 60 Rc), was placed on top of a steel plate under a load of 50 Newton, allowed to warm from room temperature to 35 ° C for 10 minutes and maintained at a temperature 35 ° C for 5 minutes. Then, at the same load of 50 Newton, a reciprocating motion was started with a frequency of 5 Hertz with a stroke length amplitude of 15 millimeters. Then the temperature was gradually raised over 10 minutes to 50 ° C and maintained at 50 ° C for 5 minutes. The load was then increased to 100 Newton and the temperature was gradually increased over the course of 1 hour to 165 ° C. The friction coefficient was recorded at a temperature of 60 to 160 ° C. The flat sample was cleaned between experiments with hexane and an emery cloth # 500. Each time a new dowel pin or dowel pin surface was used. Between experiments using test oils, an alternative test of a standard control oil was performed. The same flat sample was used until the standard control oil no longer produced reproducible results.

The test engine oil composition was SAE 10W-30 brand oil containing a dispersant, detergent, antioxidant, corrosion inhibitor, depressant additive, lowering pour point, "VI" OCP additive and anti-wear additive. A friction modifier was added to this composition as the main additive.

Table 1
Friction Coefficient Test Results Using Cameron-Plint High Frequency Friction Machine Mix ID Additive % wt. Coefficient of friction (μm) at 60 ° С Coefficient of friction (μm) at 120 ° С Coefficient of friction (μm) at 160 ° С 392-014 Example 3 1,0 0,037 0,042 0,035 392-020 Example 4 1,0 0,095 0,038 0,035 392-086 Example 5 1,0 0,057 0,033 0,027 392-089 Example 6 1,0 0,075 0,037 0,033 Without MT ¹ - 0,0 0.125 0,120 0,100 CFM ² - 1,0 0.115 0.115 0.121 ¹ The standard control oil is a 10W-30 fully formulated crankcase oil for gasoline engines that does not contain a friction modifier.
² CFM is an ashless commercially available friction modifier based on a mixture of fatty acid amides, glycerol esters and glycerol.

Example 8

Four-ball anti-wear test

The anti-wear properties of the new reaction product in a fully constituted lubricating oil were determined in a four-ball wear test in accordance with ASTM D 4172. The fully formulated lubricating oils tested also contained 1% wt. cumene hydroperoxides to simulate a working engine environment. Additives were tested for effectiveness in two engine oil compositions (see table 2) and compared with similar compositions containing or without zinc dialkyldithiophosphate. In table 3, the digital indicators of the test results (average diameter of the trace of wear, mm) decrease with increasing efficiency.

table 2
Compositions of motor oils of grade SAE 10W-30 Composition A % wt. Composition B % wt. Solvent Neutral 100 Balance Solvent Neutral 100 Balance Solvent Neutral 150 60 Solvent Neutral 150 60 Succinimide Dispersant 7.5 Succinimide Dispersant 7.5 High alkaline calcium phenolate detergent 2.0 High alkaline calcium sulfonate detergent 2.0 Calcium Sulphonate Neutral Detergent 0.5 Calcium Sulphonate Neutral Detergent 0.5 Antioxidant 0.5 Antioxidant 0.5 Corrosion inhibitor 0.1 Corrosion inhibitor 0.1 Depressant additive to lower pour point 0.1 Depressant additive to lower pour point 0.1 "VI" OCP additive 5.5 "VI" OCP additive 5.5 Antiwear Additive ¹ 1,0 Antiwear additive 1,0 ¹ In the case where “no anti-wear additive” is indicated in Table 3, Solvent Neutral 100 in the amount of 1.0 weight percent is present instead. The composition is processed so as to obtain 1 weight percent antiwear additives based on 100 percent active substance.

Table 3
Falex four-ball wear test results Compound Composition Diameter of traces of wear, mm No antiwear additives A 0.93 Zinc dialkyldithiophosphate A 0.46 Example 5 A 0.56 Example 6 A 0.85 No antiwear additives IN 0.98 Zinc dialkyldithiophosphate IN 0.53 Example 3 IN 0.44 Example 4 IN 0.78 Example 5 IN 0.44 Example 6 IN 0.70

Given the numerous changes and modifications that may take place without departing from the principles underlying the present invention, the scope of protection claimed is determined by the appended claims.

Claims (10)

1. The compound of the formula (ZN =) ₂ Mo (S ₂ CNR ₂ ) ₂ , where Z and R independently represent C ₁ -C ₁₀ branched alkyl. 2. The compound according to claim 1, where Z and R independently represent tert-butyl, isooctyl, or tert-octyl. 3. The compound according to claim 1, which is bis- (tert-butylimido) bis-diisooctyldithiocarbamato) molybdenum (VI) or bis- (tert-octylimido) bis-diisooctyldithiocarbamato) molybdenum (VI). 4. The compound according to claim 1, which is (tert-octyl N) ₂ Mo {S ₂ CN (Coco) ₂ } ₂ or (tert-butyl N) ₂ Mo {S ₂ CH (Coco) ₂ } ₂ . 5. Additive for lubricant containing a compound of the formula (ZN =) ₂ MO (S ₂ CNR ₂ ) ₂ , where Z and R independently represent C ₁ -C ₁₀ branched alkyl. 6. A method of reducing the coefficient of friction of a lubricant, comprising adding to the specified lubricant a compound of the formula (ZN =) ₂ Mo (S ₂ CNR ₂ ) ₂ , where Z and R independently represent a C ₁ -C ₁₀ branched alkyl. 7. The method according to claim 6, where Z and R independently represent tert-butyl, isooctyl, or tert-octyl. 8. The method according to claim 6, where the compound is bis (tert-butylimido) bis-diisooctyl dithiocarbamato) molybdenum (VI) or bis (tert-octylimido) bis-diisooctyl dithiocarbamato) molybdenum (VI). 9. The method according to claim 6, where the compound is (tert-octyl N) ₂ Mo {S ₂ CN (Coco) ₂ ) ₂ or (tert-butyl N) ₂ Mo (S ₂ CN (Coco) ₂ ) ₂ . 10. The method according to claim 6, where the lubricant is a lubricating oil.