ES2403780T3 - Composition of additive for transmission oil - Google Patents

Abstract

A transmission oil additive composition comprising: a) an oily dispersion of hexagonal boron nitride and b) a viscosity index improver selected from the group consisting of: i) a non-dispersing polymethacrylate and ii) a dispersing polymethacrylate, wherein the weight ratio of the hexagonal boron nitride oil dispersion to the viscosity index improver is in the range of from 99: 1 to 1:99.

Description

Composition of additive for transmission oil

The present invention relates to an additive composition for a transmission oil. More particularly, the present invention relates to an additive composition comprising an oily dispersion of hexagonal boron nitride and a viscosity index improver, in particular, an additive composition containing a selected viscosity index improver of a polymethacrylate or a dispersing polymethacrylate.

References

The following references are cited in this application as overwritten numbers:

1 Peeeler, US Pat. No. 3,313,727, Alkali Metal Borate E. P. Lubricants, issued April 11, 1967.

2Adams, US Pat. No. 3,912,643, Lubricant Containing Neutralized Alkali Metal Borates, issued October 14, 1975.

3Sims, US Pat. No. 3,819,521, Lubricant Containing Dispersed Borate and a Polyol, issued June 25, 1974.

4Adams, US Pat. No. 3,853,772, Containing Alkali Metal Borate Dispersed with a Mixture of Dispersants, issued on December 10, 1974.

5Adams, US Pat. No. 3,997,454, Lubricant Containing Potassium Borate, issued on December 14,

1,976.

6Adams, US Pat. No. 4,089,790, Synergistic Combinations of Hydrated Potassium Borate, Antiwear Agents, and Organic Sulfide Antioxidants, issued May 16, 1978.

7Adams, US Pat. No. 4,163,729, Synergistic Combinations of Hydrated Potassium Borate, Antiwear Agents, and Organic Sulfide Antioxidants, issued August 7, 1,979.

8Frost, U.S. Pat. No. 4,263,155, Lubricant Composition Containing an Alkali Metal Borate and Stabilizing Oil-Soluble Acid, issued on April 21, 1981.

9Frost, U.S. Pat. No. 4,401,580, Lubricant Composition Containing an Alkali Metal Borate and an Ester-Polyol Compound, issued on August 30, 1983.

10Frost, US Pat. No. 4,472,288, Lubricant Composition Containing an Alkali Metal Borate and an Oil-Soluble Amine Salt of a Phosphorus Compound, issued September 18, 1984.

11Clark, U.S. Pat. No. 4,534,873, Automotive Friction Reducing Composition, issued on August 13,

1,985.

12Brewster, US Pat. No. 3,489,619, Heat Transfer and Quench Oil, issued on January 13, 1970.

13 Salentine, US Pat. No. 4,717,490, Synergistic Combination of Alkali Metal Borates, Sulfur Compounds, Phosphites and Neutralized Phosphate, issued January 5, 1988.

Background of the invention

High load conditions frequently occur in gear assemblies such as those used in automobile transmissions and differentials, pneumatic tools, gas compressors, centrifuges, high pressure hydraulic systems, metal work devices and the like, as well as in many types of bearings. When used in such environments, it is classic to add an extreme pressure agent (P. E.) to the lubricant composition and, in this regard, alkali metal borates are known extreme pressure agents for such compositions. 1-11, 13 P. E. agents are added to lubricants to prevent destructive metal-metal contact in the lubrication of moving surfaces. Although under normal conditions called "hydrodynamics", a lubricant film is maintained between relatively mobile surfaces governed by lubricant parameters and mainly viscosity. However, when the load is increased, the free space between the surfaces is reduced or when the speeds of the moving surfaces are such that the oil film cannot be maintained, the "limit lubrication" condition is reached; governed largely by the parameters of the contact surfaces. Under even more stringent conditions, significant destructive contact manifests itself in various forms such as wear and fatigue of the metal when measured by ripple formation and pitting corrosion. The work of the additives of P. E., is to prevent this from happening. For the most part, PE agents have been oil soluble or easily dispersed as a stable dispersion in the oil and have largely been organic compounds that have reacted chemically to contain sulfur, halogen (mainly chlorine), salt groups of phosphorus, carboxy or carboxylate that react with the metal surface under conditions of

limit lubrication Stable dispersions of hydrated alkali metal borates have also been found to be effective as agents of P. E.

On the other hand, because hydrated alkali metal borates are insoluble in oily lubricating medium, it is necessary to incorporate borate as a dispersion in the oil and homogeneous dispersions are particularly desirable. The degree of formation of a homogeneous dispersion can be correlated with the turbidity of the oil after the addition of the hydrated alkali metal borate correlating greater turbidity with less homogeneous dispersions. To facilitate the formation of said homogeneous dispersion, it is classic to include a dispersant in such compositions. Examples of dispersants include lipophilic surfactants such as alkenyl succinimides or other nitrogen containing dispersants as well as alkenyl succinates.1-4,12 It is also classic to use alkali metal borate in particle sizes smaller than 1 micrometer to facilitate formation of homogeneous dispersion. 11

In addition, non-stick agents are often employed in automobile gearboxes to provide smooth synchronization and good displacement ability. Examples of such non-stick agents include: phosphates, phosphites, phosphonates, thiophosphates, carbamates, molybdenum dithiocarbamates and dithiophosphates.

It is also known that boron nitride has friction modifying properties in lubricants. For example, US Pat. No. 4,787,993, issued November 29, 1988 to Nagahiro, discloses an effective friction reduction lubricant comprising dispersing an aromatic resin or fine powder polyamide in a fluid grease or oil, which may additionally contain disulfide of molybdenum, molybdenum nitride or organic boron.

In addition, US Pat. No. 4,715,972, issued December 29, 1987 to Pacholke, discloses a solid lubricant additive for gear oils comprising solid lubricant particles combined with a stabilizing agent and a fluid carrier, in which the solid lubricant particles are selected from the group consisting of: molybdenum disulfide, graphite, cerium fluoride, zinc oxide, tungsten disulfide, mica, boron nitrate, boron nitride, borax, silver sulfate, cadmium iodide, lead iodide, fluoride barium, tin sulfide, fluorinated carbon, PTFE, intercalated graphite, zinc phosphide, zinc phosphate and mixtures thereof. This patent further discloses that such a lubricant additive provides the gear oil with improved demulsibility, stability and compatibility characteristics of the gear oil when it is contaminated with water.

Poly (methacrylic acid) or polymethacrylate esters are long chain esters commonly used in the lubricating oil industry as viscosity index improvers (MIV). Its molecular masses are mostly between 20,000 and 500,000. The properties of the homo- or co-polymers of the various alkyl methacrylates differ with the chain length of the alcohol used to prepare the ester and the degree of polymerization. Olefinic co-polymers (CPO) are manufactured from ethylene and propylene by means of Ziegler catalysts and are commonly used in the lubricating oil industry such as MIV. Dispersant Olefinic Co-Polymers (CPOD) are multifunctional MIVs; The viscosity enhancing effect is combined with dispersant properties by the inclusion of cyclic imides such as N-vinylimidazole and similar fragments in the polymers.

Accordingly, it is an object of the present invention to provide a composition of lubricant additives with good non-stick properties when used in transmission oils.

Summary of the invention

The present invention provides a new composition of additives for a transmission oil comprising:

a) an oily dispersion of hexagonal boron nitride and

b) a viscosity index improver selected from the group consisting of:

i) a polymethacrylate,

ii) a dispersing polymethacrylate and

wherein the weight ratio of the oily dispersion of hexagonal boron nitride to the viscosity index improver is in the range of from 99: 1 to 1:99.

Typically, the concentration of the oil dispersion of hexagonal boron nitride is 1 to 99% by weight, preferably 5 to 95% by weight and the concentration of the viscosity index improver is 1 to 99% by weight, preferably of 5 to 95% by weight, based on the total weight of the additive composition.

The additive composition of the present invention may optionally also contain an oily dispersion of hydrated alkali metal borate containing a hydrated alkali metal borate, a dispersant, optionally a detergent and a lubricant viscosity oil.

The additive composition of the present invention can be conveniently employed in both manual transmission gear oils and automatic transmission oils. Preferably, the additive composition will be employed in a manual transmission gear oil.

The present invention further provides a lubricating oil composition comprising a main amount of a lubricating viscosity transmission oil and an effective synchronizer reducing amount of the additive composition described above. Preferably, the transmission oil is a manual transmission gear oil.

Among other factors, the present invention is based in part on the surprising discovery that the only combination of an oily dispersion of hexagonal boron nitride and a certain viscosity index improver selected from a polymethacrylate, dispersing polymethacrylate and a dispersing olefin copolymer, provides a significant and unexpected reduction in synchronizer adhesion when used as a composition of additives in a manual transmission gear oil.

Detailed description of the invention

As indicated above, the present invention relates to a new additive composition for a transmission oil comprising an oily dispersion of hexagonal boron nitride and a viscosity index improver selected from the group consisting of:

to.

 a polymethacrylate,

b.

 a dispersing polymethacrylate and

wherein the weight ratio of the oily dispersion of hexagonal boron nitride to the viscosity index improver is in the range of from 99: 1 to 1:99.

Each of the components in the additive composition of the present invention will be described in more detail below. Unless stated otherwise, all percentages are percentages by weight (% by weight).

The oily dispersion of hexagonal boron nitride

The additive composition of the present invention contains an oily dispersion of hexagonal boron nitride.

Hexagonal boron nitride, or NB-h, is a graphite, hexagonal, boron nitride type, with a stratified structure and rings of 6 flat members of alternating boron and nitrogen atoms. In alternate sheets, boron atoms are directly on nitrogen atoms. Hexagonal boron nitride can be prepared by heating: boric oxide, boric acid or boric acid salts with ammonium chloride, alkali cyanides or calcium cyanamide at atmospheric pressure. Hexagonal boron nitride can also be prepared by the reaction of boron trichloride or boron trifluoride with ammonia. A discussion of hexagonal boron nitride can be found, for example, in Kirk-Othmer, Encyclopedia of Chemical Technology, Fourth Edition, Vol. 4, p. 427-429, John Wiley and Sons, New York, 1992.

In general, the oily dispersion of hexagonal boron nitride will have an average particle size of less than 1 micrometer. Preferably, the hexagonal boron nitride oil dispersion will have a particle size distribution in which 90% or more of the particles is less than about 0.5 micrometers (500 nanometers, nm), with a preferred average particle size less than about 0.3 micrometers (300 nm).

Typically, the hexagonal boron nitride oil dispersion will contain from 1 to 50% by weight of the hexagonal boron nitride solids, preferably from about 1 to about 20% by weight and more preferably from about 5 to about 15% by weight, based on the total weight of the oil dispersion.

Preferably, the hexagonal boron nitride oil dispersion will contain a surfactant as a stabilizer for the oil dispersion. Typical surfactants for use as a stabilizer include copolymers of ethylene propylene or terpolymers of ethylene, propylene and an unconjugated diene commonly known as ethylene-propylene-diene terpolymer, ethylene-propylene grafted copolymers with a vinyl functionality containing nitrogen selected from the group consisting of N-vinyl pyrrolidone and N-vinyl pyridine and the like. The ethylene-propylene copolymer generally has an average molecular weight in the range of from about 22,000 to about 200,000. A preferred surfactant is ethylene-propylene copolymer having substantially equal proportions of ethylene and propylene monomers and an average molecular weight of from about 22,000 to about 40,000. When present, the concentration of surfactant in the oily dispersion of hexagonal boron nitride will typically range from about 0.1 to about 25% by weight, preferably from about 2 to about 7% by weight and more preferably from about 3.0 to approximately 5.0% by weight, based on the total weight of the oily dispersion of hexagonal boron nitride.

The lubricating oil used to prepare the hexagonal boron nitride oil dispersion can be selected from the same group of natural or synthetic lubricating oils described above for use in the preparation of the hydrated alkali metal borate oil dispersion, but it has been found that they are satisfactory other carrier fluids, including vegetable oils such as rapeseed oil; liquid hydrocarbons such as aliphatic and aromatic naphtha and mixtures thereof; synthetic lubricating fluids such as polyalphaolefins, polyglycols, diester fluids and mixtures of these liquids. On the other hand, the oil used in the formation of the hexagonal boron nitride oil dispersion may be the same or different than the lubricating oil used in the preparation of the hydrated alkali metal borate oil dispersion. Typical oils for preparing the oily dispersion of hexagonal boron nitride include the base oils of Group I and Group II, such as neutral oil with solvent 150.

In general, the hexagonal boron nitride oil dispersion is present in the additive composition of the present invention in the range of from 1 to 99% by weight, preferably from 5 to 95% by weight and more preferably from about 10 to about 90% by weight, based on the total amount of the additive composition.

Viscosity index improver (IV improver)

The additive composition of the present invention contains a polymethacrylate, dispersing polymethacrylate or an IV improver of the dispersing olefinic copolymer.

A. Polymethacrylate (PMA) or Dispersant Polymethacrylate

Typically, the polymethacrylate IV improvers employed in the present invention are polymeric methacrylates containing short, intermediate and long chain hydrocarbon side chains. The short chain hydrocarbon side chains typically have from about 1 to about 7 carbon atoms. For example, both methyl and butyl methacrylates (or n-butyl, isobutyl or mixtures of the two) have been used. Methyl methacrylate is the most common. The intermediate chain hydrocarbon side chains typically contain from about 8 to about 15 carbon atoms and can be derived from alcohols including 2-ethylhexyl alcohol, isodecyl alcohol and mixtures of alcohols which may be, for example, mixtures of C8 to C10, C12 alcohols to C14 or C12 to C15. The long chain hydrocarbon side chains will generally contain about 16 or more carbon atoms and may be based, for example, on mixtures of C16 to C18 or C16 to C20 alcohols.

The polymethacrylate IV improvers that can be employed in the present invention are of any type of non-dispersing or dispersing type polymethacrylate compounds that are used as IV improvers for a lubricating oil.

The non-dispersant type polymethacrylate IV improvers may be a polymer of a compound represented by the formula:

CH2 = C (CH3) -CO2-R1

In formula (1) R1 is a straight or branched chain alkyl group such as the groups: methyl, ethyl, propyl, butyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl , heptadecyl and octadecyl.

Dispersant can be incorporated into WFP with an appropriate polar monomer by any number of methods known to the skilled person such as copolymerization, graft polymerization or post-reaction of a reactive species in or on the polymer. Typically, such methods involve the incorporation of a polar group from nitrogen or oxygen. The nitrogen-based groups come from amines, for example, polyalkyleneamines such as diethylenetriamine and triethylenetetramine. Oxygen-based groups are alcohol derivatives such as hydroxyethyl methacrylates or ether containing methacrylates. Although nitrogen-based PMAs are exemplified in the present invention, oxygen-based PMAs are also considered within the scope of the present invention. Examples of oxygen-based PMA are those from polyhydric alcohols such as glycols, trivalent alcohols such as glycerol and higher alcohols, such as erythritol, pentaerythritol, mannitol and the like. On the other hand, PMA containing ether are also known in the art. More details of oxygen-based PMA can be found, for example, in US Pat. Us.

3,249,545 and 3,052,648.

Specific examples of the IV dispersants of dispersant polymethacrylate are the copolymers obtained by copolymerization of one or more monomers selected from compounds represented by the formula (1) with one

or more nitrogen-containing monomers selected from compounds represented by formulas (2) and (3):

CH2 = C (R2) CO2-R3-X1

Formula 2 5

CH2 = C (R4) -X2

Formula 3

In formulas (2) and (3) R2 and R4 are each independently hydrogen or methyl, R3 is a straight or branched chain alkylene group having from about 1 to about 18 carbon atoms, such as ethylene, propylene groups , butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, tetradecylene, pentadecylene, hexadecylene, heptadecylene and octadecylene, X1 and X2 are each independently an amino or heterocyclic moiety having about 1 or about 2 nitrogen atoms and 0 to about 2 oxygen atoms. Specific examples of X1 and X2 are dimethylamino, diethylamino, dipropylamino, dibutylamino, anilino, toluidino, xylidino, acetylamino, benzoylamino, morpholino, pyrolyl, pyridyl, methylpyridyl, pyrolidinyl, piperidinyl, quinonyl, pyrrolidonyl, pyrrolidonozino, pyrrolidonoidine.

Specific examples of the nitrogen-containing monomers represented by the formula (2) or (3) are: dimethylaminomethyl methacrylate, diethylaminomethyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 2-methyl-5-vinylpyridine, morpholinomethyl methacrylate, methacrylate of morpholinoethyl, N-vinylpyrrolidone, and mixtures thereof.

A particular beneficial PMA employed in the present invention is an ester polymer having mainly from about 1 to about 20, preferably from about 8 to about 14, carbon atoms. It can be prepared by a polymerization reaction with a basic monomer and an azoic peroxide or initiator in a hydrocarbon solvent such as toluene or a paraffin or synthetic base oil. The basic monomers used to prepare PMA are mainly monocarboxylic acid esters such as: methacrylate, acrylate, crotonate, tiglycate and angelicate. PMA can also be prepared by reaction with olefinic copolymers (ie, ethylene-propylene copolymer) in oil.

The average molecular weight of WFP will be in the range of from about 20,000 to about

500,000 Preferably, the molecular weight will range from about 50,000 to about 300,000 and more preferably, from about 80,000 to about 150,000.

A further discussion of PMA IV improvers and dispersant PMA IV improvers can be found, for example, in "Lubricant Additives Chemistry and Applications", Author, Leslie R. Rudnick, Chapters 5 and 11, Marcel Dekker, Inc, New York 2003 and US Pat. No. 6,642,189.

In general, the IV Enhancer is present in the additive composition of the present invention in the range of from 1 to 99% by weight, preferably from 5 to 95% by weight and more preferably from about 10 to about 90% by weight. , based on the total weight of the additive composition.

A further discussion of IV dispersant CPO enhancers can be found, for example, in "Lubricant Additives; Chemistry and Applications", Author, Leslie R. Rudnick, Chapter 5 and 10, Marcel Dekker, Inc, New York

2003

Hydrated alkali metal borate

The additive composition of the present invention may optionally also contain an oily dispersion of hydrated alkali metal borate as described above.

Hydrated alkali metal borates are known in the art. Representative patents that disclose borates and suitable manufacturing methods include US Pat. Nos. 3,313,727; 3,819,521; 3,853,772; 3,912,643; 3,997,454 and 4,089,790.1-6

Hydrated alkali metal borates suitable for use in the present invention can be represented by the following general formula:

M2O! XB2O3! YH2O

wherein M is an alkali metal, preferably sodium or potassium; x is a number from about 2.5 to about 4.5 (both integer and fractional) and y is a number from about 1.0 to about 4.8. More preferred are hydrated potassium borates, in particular hydrated potassium triborates. Hydrated borate particles will generally have an average particle size of less than 1 micrometer.

In the alkali metal borates used in this invention, the boron to alkali metal ratio will preferably range from about 2.5: 1 to about 4.5: 1.

The oily dispersions of hydrated alkali metal borates are generally prepared by formation, in deionized water, of a solution of alkali metal hydroxide and boric acid, optionally in the presence of a small amount of the corresponding alkali metal carbonate. The solution is then added to a

lubricant composition comprising an oil of viscosity of the lubricant, a dispersant and any optional additive that has to be included therein (e.g., a detergent or other optional additives) to form an emulsion that is then dehydrated.

Due to their retention of hydroxyl groups on the borate complex, these complexes are referred to as "hydrated alkali metal borates" and compositions containing oil / water emulsions of these hydrated alkali metal borates are referred to as "oily dispersions of borates. alkali metal hydrated. "

Preferred oily dispersions of alkali metal borates will have a boron to alkali metal ratio of from about 2.5: 1 to about 4.5: 1. In another preferred embodiment, the hydrated alkali metal borate particles will generally have an average particle size of less than 1 micrometer. In this regard, it has been found that the hydrated alkali metal borates employed in this invention will preferably have a particle size where 90% or more of the particles is less than 0.6 micrometers.

In the oily dispersion of hydrated alkali metal borate, the hydrated alkali metal borate will generally comprise from 10 to 75% by weight, preferably from about 25 to about 50% by weight, more preferably from about 30 to about 40% by weight of the total weight of the oily dispersion of hydrated borate.

In general, when used, the oily dispersion of hydrated alkali metal borate is present in the additive composition of the invention in the range of from about 10 to about 90% by weight, based on the total weight of the additive composition .

The additive compositions and lubricant compositions of the present invention may further employ surfactants, detergents, other dispersants and other conditions as described above and known to the person skilled in the art. Optionally, the additive compositions may contain an alkylaromatic or polyisobutenyl sulfonate.

The oily dispersions of hydrated alkali metal borates employed in this invention generally comprise a dispersant, an oil of lubricant viscosity and optionally a detergent, which are further described below.

The dispersant employed in the oily dispersion of hydrated alkali metal borate that can be optionally employed in the present invention can be dispersant without ashes such as an alkenyl succinimide, an alkenyl succinic anhydride, an alkenyl succinate ester and the like or mixtures of said dispersants.

Ashless dispersants are generally divided into several groups. One such group refers to copolymers containing a carboxylate ester with one or more additional polar functions, including amine, amide, imine, imide, hydroxycarboxyl and the like. These products can be prepared by copolymerization of long chain alkyl acrylates or methacrylates with monomers of the above function. Such groups include alkyl methacrylate-vinyl pyrrolidinone copolymers, alkyl methacrylate-dialkylaminoethyl methacrylate copolymers and the like. Additionally, high molecular weight amides and polyamides or esters and polyesters such as tetraethylene pentamine, polyvinyl polyesterarates and other polyesteramides can be used. Preferred dispersants are N-substituted long chain alkenyl succinimides.

Alkenyl succinimides usually come from the reaction of alkenyl succinic acid or anhydride and alkylene polyamines. It is generally considered that these compounds have the formula:

wherein R7 is a substantially hydrocarbon radical with a molecular weight of about 400 to about 3,000, that is, R7 is a hydrocarbyl radical, preferably an alkenyl radical, containing from about 30 to about 200 carbon atoms; Alk is an alkylene radical of from about 2 to about 10, preferably from about 2 to about 6, carbon atoms, R8, R9 and R10 are selected from a C1 to C4 alkyl or alkoxy or hydrogen, preferably hydrogen and z is an integer from about 0 to about 10, preferably from about 0 to about 3. The actual reaction product of alkylene succinic acid or alkylene polyamine will comprise a mixture of compounds including succinamic acids and succinimides. However, it is usual

designate this reaction product as a succinimide of the described formula, since this will be a major component of the mixture. See, for example, US Pat. Nos. 3,202,678; 3,024,237 and

3,172,892.

These N-substituted alkenyl succinimides can be prepared by reacting maleic anhydride with an olefinic hydrocarbon followed by reacting the resulting alkenyl succinic anhydride with the alkylene polyamine. The radical R 1 of the above formula, that is, the alkenyl radical, is preferably derived from a polymer prepared from an olefinic monomer containing from about 2 to about 5 carbon atoms. Thus, the alkenyl radical is obtained by polymerization of an olefin containing from about 2 to about 5 carbon atoms to form a hydrocarbon with a molecular weight ranging from about 400 to about 3,000. Said olefinic monomers are exemplified by: ethylene, propylene, 1-butene, 2-butene, isobutene and mixtures thereof.

Preferred polyalkyleneamines used to prepare succinimides are of the formula:

where z is an integer from about 0 to about 10 and Alq, R8, R9 and R10 are as defined above.

Alkyleneamines mainly include methylenamines, ethylenamines, butylenamines, propylenamines, pentylenamines, hexylenamines, heptylenamines, octylenamines, other polymethylenamines and also the cyclic and higher homologs of such amines such as piperazine and substituted aminoalkyl piperazines. Are specifically exemplified by ethylenediamine, triethylenetetramine, propylenediamine, decametildiamina, octamethylenediamine, diheptametilentriamina, tripropylenetetramine, tetraethylenepentamine, trimethylenediamine, pentaethylenehexamine, ditrimetilentriamina, 2-heptyl-3- (2-aminopropyl) imidazoline, 4-methylimidazoline, N, N-dimethyl- 1,3-propanediamine, 1,3bis (2-aminoethyl) imidazoline, 1- (2-aminopropyl) -piperazine, 1,4-bis (2-aminoethyl) piperazine and 2-methyl-1- (2-aminobutyl) piperazine. Higher homologues such as are obtained by condensation of two or more of the alkyleneamines illustrated above are also useful.

Ethylenamines are especially useful. They are described in some detail under the heading "Ethylene Amines" in Encyclopedia of Chemical Technology, Kirk-Othmer, Vol. 5, p. 898-905 (Interscience Publishers, New York, 1,950).

The terminology "ethylenamine" is used in a generic sense to indicate a class of polyamines that make up the majority of the structure:

H2N (CH2CH2NH) aH

where a is an integer from about 1 to about 10.

Thus, it includes, for example, ethylenediamine, diethylenetriamine, triethylene tetraamine, tetraethylenepentamine, pentaethylenehexamine and the like.

Also included within the term "alkenyl succinimides" are succinimides subsequently treated such as post-treatment procedures involving ethylene carbonate disclosed by Wollenberg, et al., US Pat. No. 4,612,132; Wollenberg, et al., U.S. Pat. No. 4,746,446 and the like as well as other post-treatment procedures, each of which is incorporated herein by reference in its entirety.

Preferably, the dispersant component, such as a polyalkylene succinimide, comprises from 2 to 40% by weight, more preferably from about 5 to about 20% by weight and even more preferably from about 5 to about 15% by weight, of the weight of the dispersion Hydrated alkali metal borate oil.

Polyalkylene succinic anhydrides or a nitrogen-free derivative of polyalkylene succinic anhydride (such as succinic acids, mono- or di-metal salts of Group I and / or Group II of succinic acids, succinate esters formed by the reaction of a polyalkylene succinic anhydride, acid chloride or other derivative with an alcohol and the like) are also dispersants suitable for use in the compositions of this invention.

The polyalkylene succinic anhydride is preferably a polyisobutenyl succinic anhydride. In a preferred embodiment, the polyalkylene succinic anhydride is a polyisobutenyl succinic anhydride with a number average molecular weight of at least 500, more preferably at least about 900 to about 3,000 and even more preferably at least about 900 to about 2,300.

In another preferred embodiment, a mixture of polyalkylene succinic anhydrides is employed. In this embodiment, the mixture preferably comprises a low molecular weight polyalkylene succinic anhydride component and a high molecular weight polyalkylene succinic anhydride component. More preferably, the low molecular weight component has a number average molecular weight of from about 500 to below 1,000 and the high molecular weight component has a number average molecular weight of from about 1,000 to about 3,000. Even more preferably, both the low and high molecular weight components are polyisobutenyl succinic anhydrides. Alternatively, various polyalkylene succinic anhydride components of various molecular weights can be combined as a dispersant as well as a mixture of the other dispersants referred to above as identified above.

As indicated above, polyalkylene succinic anhydride is the reaction product of a polyalkylene (preferably polyisobutene) with maleic anhydride. Classic polyisobutene or methylvinylidene polyisobutene can be used in the preparation of said polyalkylene succinic anhydrides. Thermal processes, chlorination, free radicals, acid catalyzed or any other can be used in this preparation. Examples of suitable polyalkylene succinic anhydrides are PIBSA thermal (polyisobutenyl succinic anhydride) described in US Pat. No. 3,361,673; Chlorination PIBSA described in US Pat. No. 3,172,892; a mixture of thermal and chlorination PIBSA described in US Pat. No. 3,912,764; PIBSA of high succinic ratio described in US Pat. No. 4,234,435; PoliPIBSA described in US Pat. Nos. 5,112,507 and 5,175,225; High succinic ratio polyPIBSA described in US Pat. Nos. 5,565,528 and 5,616,668; PIBSA of free radicals described in US Pat. Nos. 5,286,799, 5,319,030 and 5,625,004; PIBSA manufactured from methylvinylidene-superior polybutene described in US Pat. Nos. 4,152,499, 5,137,978 and 5,137,980; PIBSA of high succinic ratio manufactured from methylvinylidene-polybutene higher described in European Patent Application Publication No. EP 355 895; PIBSA terpolymer described in US Pat. No. 5,792,729; PIBSA of sulfonic acid described in US Pat. No. 5,777,025 and European Patent Application Publication No. EP 542 380 and purified PIBSA described in US Pat. No. 5,523,417 and European Patent Application Publication No. EP 602 863.

Preferably, the polyalkylene succinic anhydride or other dispersing component comprises from 2 to 40% by weight, more preferably from about 5 to about 20% by weight and even more preferably from about 5 to about 15% by weight, of the weight of the dispersion Hydrated alkali metal borate oil.

Typically, in the oily dispersion of hydrated alkali metal borate, the hydrated alkali metal borate is in a ratio of at least 2: 1 with respect to the polyalkylene succinic anhydride or other dispersant, although it is preferably in the range of 2: 1 at about 10: 1. In a more preferred embodiment the ratio is at least 5: 1. In another preferred embodiment, mixtures as defined above of polyalkylene succinic anhydrides are employed.

The oily dispersion of hydrated alkali metal borate that is optionally employed in the additive compositions of the present invention may optionally contain a detergent. There are a number of materials that are suitable as detergents for the purpose of this invention. These materials include phenates (high base excess or low base excess), phenate stearates, phenolates, salicylates, phosphonates, thiophosphonates and high base excess sulphonates and mixtures thereof. Preferably, sulfonates are used, such as sulfonates with high excess base, sulfonates with low base excess or phenoxysulfonates. In addition the sulfonic acids themselves can also be used.

The sulphonate detergent is preferably an alkali metal or alkaline earth metal salt of a hydrocarbylsulfonic acid having from about 15 to about 200 carbons. Preferably, the term "sulfonate" includes sulfonic acid salts from petroleum products. Such acids are known in the art. They can be obtained by treating petroleum products with sulfuric acid or sulfur trioxide. The acids thus obtained are known as petroleum sulfonic acids and salts as petroleum sulfonates. Most petroleum products that become sulphonated contain a hydrocarbon group that is solubilized in oil. Also included within the meaning of "sulfonate" are sulfonic acid salts of synthetic alkylaryl compounds. These acids are also prepared by treating an alkylaryl compound with sulfuric acid or sulfur trioxide. At least one alkyl substituent of the aryl ring is a group that is solubilized in oil, as discussed above. The acids thus obtained are known as alkylarylsulfonic acids and the salts as alkylarylsulfonates. The sulfonates in which the alkyl is straight chain are the known linear alkylaryl sulfonates.

The acids obtained by sulfonation are converted into metal salts by neutralization with an alkali metal or alkaline earth metal compound that reacts with base to provide Group I or Group II metal sulphonates. In general, acids are neutralized with an alkali metal base. The alkaline earth metal salts are obtained

from the alkali metal salt by metathesis. Alternatively, sulfonic acids can be neutralized directly with an alkaline earth metal base. The sulfonates may then be with excess base, although, for the purposes of this invention, excess base is not necessary. Materials with excess base and methods for preparing such materials are known to the person skilled in the art. See, for example, US Pat. de LeSuer No. 3,496,105, issued on February 17, 1970, in particular columns 3 and 4.

Sulfonates are present in the oil dispersion in the form of alkali and / or alkaline earth metal salts or mixtures thereof. Alkali metals include lithium, sodium and potassium. Alkaline earth metals include magnesium, calcium and barium, of which the last two are preferred.

Particularly preferred, however, due to their wide availability, salts of petroleum sulfonic acids, in particular petroleum sulfonic acids obtained by sulfonation of various hydrocarbon fractions such as lubricating oil fractions and aromatic rich extracts that are obtained by extracting a hydrocarbon oil with a selective solvent, extracts that can be rented, if desired, before sulfonation by reacting them with olefins or alkyl chlorides by means of an alkylation catalyst; organic polysulfonic acids such as benzenedisulfonic acid that may or may not be rented and the like.

Preferred salts for use in the present invention are those of alkylated aromatic sulfonic acids in which the radical or alkyl radicals contain at least about 8 carbon atoms, for example from about 8 to about 22 carbon atoms. Another preferred group of sulfonate starting materials are aliphatic-substituted cyclic sulfonic acids in which the aliphatic substituents or substituents contain a total of at least 12 carbon atoms, such as alkylarylsulfonic acids, alkylcycloaliphatic sulfonic acids, alkylheterocyclic sulfonic acids and aliphatic sulfonic acids in which the radical or aliphatic radicals contain a total of at least 12 carbon atoms. Specific examples of these oil-soluble sulfonic acids include petroleum sulfonic acids, mono- or polysubstituted wax naphthalenesulfonic acids, substituted sulfonic acids, such as cetylbenzenesulfonic acids, cetylphenylsulfonic acids and the like, aliphatic sulfonic acid, such as paraffin wax sulfonic acids , hydroxy-substituted paraffin wax sulfonic acids, etc., cycloaliphatic sulfonic acids, petroleum naphthalenesulfonic acids, cetylcyclopentylsulfonic acid, mono- and poly-substituted cyclohexylsulfonic acids with wax and the like. The terminology "petroleum sulfonic acids" is intended to cover all sulfonic acids that come directly from petroleum products.

Typical Group II metal sulfonates suitable for use in the present invention include the metal sulfonates exemplified as follows: white calcium benzenesulfonate oil, white barium benzenesulfonate oil, white magnesium benzenesulfonate oil, calcium dipolipropenbenzenesulfonate, barium dipolipropenbenzenesulfonate, Magnesium dipolipropenbenzenesulfonate, calcium mahogany petroleum sulphonate, barium mahogany petroleum sulphonate, magnesium mahogany petroleum sulphonate, calcium triaconylsulfonate, magnesium triacontylsulfonate, calcium lauryl sulphonate, barium lauryl sulphonate, magnesium lauryl sulfonate, etc. The concentration of metal sulphonate that can be used can vary over a wide range, depending on the concentration of alkali metal borate particles. When present, however, the detergent concentration will generally range from about 0.2 to about 10% by weight and preferably from about 3 to about 7% by weight, based on the total weight of the oily dispersion of hydrated borate. In addition, the compositions of this invention may contain a mixture of both a metal sulphonate and an ash-free dispersant, as described above, where the ratio is a factor in achieving the proper stability of the oily dispersion of hydrated alkali metal borate.

The viscosity oil of the lubricant used to form the oily dispersions of hydrated alkali metal borate can be any hydrocarbon-based lubricating oil or a synthetic base oil stock. Likewise, these lubricating oils can be added to the oil dispersions and additive compositions that contain them, as described herein, in additional amounts, to form finished lubricating oil compositions. Lubricating oils based on hydrocarbons may come from synthetic or natural sources and may be paraffinic, naphthenic or aromatic bases or mixtures thereof. The diluent oil may be natural or synthetic and may be different viscosity grades.

In the oily dispersion of hydrated alkali metal borate, the lubricating oil typically comprises from about 30 to about 70% by weight, more preferably from about 45 to about 55% by weight, based on the total weight of the oily dispersion of borate from alkaline hydrated metal.

When the oily dispersion of hydrated alkali metal borate is employed, it is present in the additive composition of the present invention in the range of from about 1 to about 99% by weight, preferably from about 5 to about 95% by weight, based on the total weight of the additive composition.

Formulations

The additive composition of the present invention containing the hexagonal boron nitride oily dispersion and IV improver, and optionally, the oily dispersion of hydrated alkali metal borate, can also be mixed with additional additives to form additive containers containing The present additive compositions. These additive packages typically comprise from about 10 to about 80% by weight of the additive composition of the present invention described above and from about 90 to about 20% by weight of one or more of the classic additives selected from the group consisting of : ashless dispersants (0-10% by weight), detergents (0-5% by weight), sulfurized hydrocarbons (0-40% by weight), dialkyl hydrogen phosphate (0-15% by weight), zinc dithiophosphates ( 0-20% by weight), alkylammonium phosphates and / or thio-dithiophosphates (0-20% by weight), phosphites (0 to 10% by weight) fatty acid esters of polyalcohols (0-10% by weight), 2,5-dimercaptothiadiazole (0-5% by weight), benzotriazole (0-5% by weight), dispersed molybdenum disulfide (05% by weight), foam inhibitors (0-2% by weight) and imidazolines (0 -10% by weight) and the like, in which each% by weight is based on the total weight of the additive composition.

Completely formulated finished lubricating oil compositions of this invention can be formulated from these additive packages in additional mixing with an oil of lubricant viscosity. Preferably, the additive package described above is added to a base oil of lubricant viscosity in an amount of from about 1 to about 40% by weight, preferably from about 2 to about 20% by weight, to provide the oil composition finished lubricant, in which the% by weight of the additive container is based on the total weight of the lubricating oil composition.

A variety of other additives may be present in the lubricating oils of the present invention. These additives include antioxidants, oxide inhibitors, corrosion inhibitors, extreme pressure agents, antifoaming agents, other anti-wear agents and a variety of other additives known in the art.

Examples

The invention will be further illustrated by the following examples, which explain advantageous embodiments in particular. Although the examples are provided to illustrate the present invention, it is not desired to limit it.

Example 1

The additive composition of the present invention was evaluated in a lubricating oil for its non-stick properties after a test using an SAE No. 2 bank, which evaluates transmission fluids during synchronization. The friction pairs used in this bench comprised a brass synchronizer ring and a steel gear cone.

During each cycle of the test, the cone is rotated at a certain speed, then the ring moves along the axis of the cone for braking until it locks. At the end of each cycle, the ring is released.

If adhesion occurs, adhesion torque is measured when cone rotation resumes. During the test, the lubricating oil and metal parts are heated to a temperature between about 60 ° C and about 90 ° C. The contact pressure is approximately 20 MPa and the initial slip speed is 1.6 m / s.

The anti-adhesion coefficient for this test was calculated as follows:

Anti-adhesion coefficient = 1- (Number of cycles with adhesion)

(Total number of cycles under test)

Accordingly, an anti-adhesion coefficient of 0 indicates the presence of cone in the ring that adheres during each cycle of the test. Conversely, an anti-adhesion coefficient of 1 indicates that no adhesion was observed during the entire duration of the test. Thus, the higher the anti-adhesion coefficient, up to a maximum of 1, the better the anti-adhesion of the lubricating oil.

The test lubricating oil compositions were formulated as follows, all formulated oils have the same viscosity (approximately 9x10-6 m2 / s (9 cSt)):

Lube Composition 1

Lubricant composition 1 was prepared containing the following:

a) 10% by weight of an oily dispersion of hexagonal boron nitride, wherein the oily dispersion contained approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N neutral oil containing a stabilizing agent,

b) 12% by weight of a long chain polymethacrylate IV improver sold under the name Viscoplex® 0-113 (available at RohMax Additives GmbH, Darmstadt, Germany) and c) 78% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lube Composition 2

Lubricant composition 2 was prepared containing the following: a) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N neutral oil which contained a stabilizing agent,

b) 12% by weight of a long-chain dispersant IV polyethacrylate improver sold under the designation Viscoplex® 0-110 (available from RohMax Additives GmbH, Darmstadt, Germany) and c) 78% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lube Composition 3

Lubricant composition 3 was prepared containing the following: a) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N neutral oil which contained a stabilizing agent,

b) 12% by weight of a Short Chain Polymethacrylate IV Enhancer sold under the name Viscoplex® 0-030 (available at RohMax Additives GmbH, Darmstadt, Germany) and c) 78% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lubricant composition 4 (not the invention)

Lubricant composition 4 was prepared containing the following: a) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N neutral oil which contained a stabilizing agent,

b) 12% by weight of a dispersant IV ethylene-propylene olefin copolymer with a weight average molecular weight of approximately 39,000 (Paratone® 8500 available from Chevron Oronite Company, LLC, San Ramon, California) and

c) 78% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lube Composition 5 Lubricant composition 5 was prepared containing the following: a) 7% by weight of an oily dispersion of hydrated potassium triborate, in which the oily dispersion contained

approximately 30% by weight of hydrated potassium triborate, dispersed in a 150 N neutral oil, b) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained

approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N neutral oil which contained a stabilizing agent, c) 12% by weight of a long chain polymethacrylate IV improver sold under the name Viscoplex®

0-113 (available at RohMax Additives GmbH, Darmstadt, Germany), and d) 71% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lubricant composition A (comparative) Comparative lubricant composition A was prepared containing the following: a) 7% by weight of an oily dispersion of hydrated potassium triborate, in which the oily dispersion contained

approximately 30% by weight of the hydrated potassium triborate, dispersed in a 150 N neutral oil and b) 93% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil.

Lubricant composition B (comparative) Comparative lubricant composition B was prepared containing the following: a) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained

approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N 5 neutral oil containing a stabilizing agent and b) 90% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lubricant composition C (comparative): Comparative lubricant composition C was prepared containing the following: a) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained approximately 10% by weight of hexagonal boron nitride solids, dispersed in a neutral oil 150 N

containing a stabilizing agent, b) 12% by weight of a non-dispersant type ethylene-propylene olefin copolymer IV improver with a weight average molecular weight of approximately 90,000 (Paratone® 8002 available from Chevron Oronite Company, LLC, San Ramon, California), and

15 c) 78% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lubricant composition D (comparative): Comparative lubricant composition D was prepared containing the following: a) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained

approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N 20 neutral oil containing a stabilizing agent, b) 0.5% by weight of a polyisobutenyl mono-succinimide and c) 89.5% in weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. Lubricant composition E (comparative): Comparative composition of lubricant E was prepared containing the following:

25 a) 10% by weight of an oily dispersion of hexagonal boron nitride, in which the oily dispersion contained approximately 10% by weight of the hexagonal boron nitride solids, dispersed in a 150 N neutral oil containing a stabilizing agent

b) 0.5% by weight of a polyisobutenyl bis-succinimide and c) 89.5% by weight of a 50/50 mixture of neutral oil (150 N plus 600 N) and synthetic polyalphaolefin oil. 30 Table 1

Sample

No. of Cycles with Cone on Ring that Adheres Total Number of Cycles Nonstick Coefficient

Base oil

5,000 5,000 0

Comparative composition A

8,100 8,100 0

Comparative composition B

6,600 6,600 0

Comparative composition C

5,700 5,700 0

Comparative composition D

6,400 6,400 0

Comparative composition E

8,100 8,100 0

Composition 1

500 1,050 7,100 5,600 0.93 0.81

Composition 2

100 6,800 0.99

Composition 3

1,200 6,850 0.82

Composition 4 (not the invention)

200 20,000 0.99

Composition 5

650 20,000 0.97

The above data demonstrate that the additive composition of the present invention provides significant anti-adhesion performance and shows a marked improvement over the comparative compositions.

From the above description, various modifications and changes in the invention described above will take place for those skilled in the art. All such modifications being within the scope of the appended claims, it is desired that they be included herein.

Claims (21)

1. A composition of additives for a transmission oil comprising: a) an oily dispersion of hexagonal boron nitride and b) a viscosity index improver selected from the group consisting of: i) a non-dispersing polymethacrylate and ii) a dispersing polymethacrylate, wherein the weight ratio of the oily dispersion of hexagonal boron nitride to the viscosity index improver is in the range of from 99: 1 to 1:99.

2.

The additive composition according to claim 1, wherein the weight ratio of the oily dispersion of hexagonal boron nitride to the viscosity index improver is in the range of from 5:95 to 95: 5.

3.

 The additive composition according to claim 1, wherein the oily dispersion of hexagonal boron nitride has a particle size distribution in which 90% or more of the particles are smaller than 0.5 micrometers.

Four.

 The additive composition according to claim 1, wherein the oily dispersion of hexagonal boron nitride contains an oil of viscosity of the lubricant and 1 to 50% by weight of solids of hexagonal boron nitride, based on the total weight of the oil dispersion

5.

 The additive composition according to claim 4, wherein the oily dispersion of hexagonal boron nitride further contains a surfactant as a stabilizer.

6.

 The additive composition according to claim 1, wherein the oily dispersion of hexagonal boron nitride is present in the additive composition in the range of from 10 to 90% by weight, based on the total weight of the additive composition.

7.

 The additive composition according to claim 1, wherein the non-dispersing polymethacrylate contains short chain hydrocarbon side chains containing 1 to 7 carbon atoms, intermediate chain hydrocarbon side chains containing 8 to 15 carbon atoms or chains Long chain hydrocarbon sides containing 16 or more carbon atoms.

8.

The additive composition according to claim 1, wherein the dispersing polymethacrylate contains short chain hydrocarbon side chains containing 1 to 7 carbon atoms, intermediate chain hydrocarbon side chains containing 8 to 15 carbon atoms or side chains of long chain hydrocarbons containing 16 or more carbon atoms.

9.

 The additive composition according to claim 1, further comprising an oily dispersion of hydrated alkali metal borate.

10.

 The additive composition according to claim 9, wherein the alkali metal in the hydrated alkali metal borate is sodium or potassium.

eleven.

 The additive composition according to claim 10, wherein the alkali metal is potassium.

12.

 The additive composition according to claim 9, wherein the hydrated alkali metal borate is hydrated potassium triborate.

13.

 The additive composition according to claim 9, wherein the oily dispersion of hydrated alkali metal borate contains a hydrated alkali metal borate, a dispersant and an oil of lubricant viscosity.

14.

 The additive composition according to claim 13, wherein the oily dispersion of hydrated alkali metal borate contains from 10 to 75% by weight of the hydrated alkali metal borate, based on the total weight of the oily dispersion.

fifteen.

 The additive composition according to claim 14, wherein the oily dispersion of hydrated alkali metal borate contains from 2 to 40% by weight of the dispersant, based on the total weight of the oily dispersion.

16.

 The additive composition according to claim 15, wherein the oily dispersion of hydrated alkali metal borate further contains a detergent.

17.

 The additive composition according to claim 16, wherein the oily dispersion of hydrated alkali metal borate contains 0.2 to 10% by weight of the detergent, based on the total weight of the oily dispersion.

18.

 The additive composition according to claim 9, wherein the oily dispersion of hydrated alkali metal borate is present in the additive composition in the range of from 10 to 90% by weight, based on the total weight of the additive composition .

19. A lubricating oil composition comprising a main amount of a transmission oil of 5 viscosity of the lubricant and a reducing amount of effective synchronizer adhesion of an additive composition comprising: a) an oily dispersion of hexagonal boron nitride and b ) a viscosity index improver selected from the group consisting of: i) a non-dispersing polymethacrylate and Ii) a dispersing polymethacrylate, in which the weight ratio of the oily dispersion of hexagonal boron nitride to the viscosity index improver is in the range of 99: 1 to 1: 99. 20. The lubricating oil composition according to claim 19, wherein the weight ratio of the oily dispersion of hexagonal boron nitride to the viscosity index improver is in the range of from 5:95 to 95: 5. The lubricating oil composition according to claim 19, wherein the lubricating oil composition contains from 1 to 20% by weight of the additive composition, based on the total weight of the lubricating oil composition. 22. The use of an additive composition according to any one of claims 1 to 19 in a manual transmission gear oil.