ES2329446T3 - ADDITIVE COMPOSITION FOR TRANSMISSION OIL CONTAINING A HYDRAATED ALKALINE METAL BORATE AND HEXAGONAL BORUS NITRIDE. - Google Patents

Abstract

Disclosed are additive compositions for transmission oils comprising an oil dispersion of a hydrated alkali metal borate and an oil dispersion of hexagonal boron nitride, as well as lubricating oil compositions containing the same.

Description

Additive composition for transmission oil which contains a hydrated alkali metal borate and boron nitride hexagonal.

Field of the Invention

This invention relates to a composition of additive for a transmission oil. More particularly, this invention refers to an additive composition comprising a oily dispersion of a hydrated alkali metal borate and a oily dispersion of hexagonal boron nitride, as well as a Lube oil composition that contains the same.

References

The following references are cited in this request indicating the superscript numbers:

1 Peeler , U.S. Patent No. 3,313,727, Alkali Metal Borate EP Lubricants , published April 11, 1967.

2 Adams , U.S. Patent No. 3,912,643, Lubricant Containing Neutralized Alkali Metal Borates , published October 14, 1975.

3 Sims , U.S. Patent No. 3,819,521, Lubricant Containing Dispersed Borate and Poliol , published June 25, 1974.

4 Adams , U.S. Patent No. 3,853,772, Lubricant Containing Alkali Metal Borate Dispersed with a Mixture of Dispersants , published December 10, 1974.

5 Adams , U.S. Patent No. 3,997,454, Lubricant Containing Potassium Borate , published December 14, 1976.

6 Adams , U.S. Patent No. 4,089,790, Synergistic Combinations of Hydrated Potassium Borate, Antiwear Agents and Organic Sulfide Antioxidants , published May 16, 1978.

7 Adams , U.S. Patent No. 4,163,729, Synergistic Combinations of Hydrated Potassium Borate, Antiwear Agents and Organic Sulfide Antioxidants , published August 7, 1979.

8 Frost , U.S. Patent No. 4,263,155, Lubricant Composition Containing an Alkali Metal Borate and Stabilizing Oil-soluble Acid , published April 21, 1981.

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

10 Frost , U.S. Patent No. 4,472,288, Lubricant Composition Containing an Alkali Metal Borate and an Oil-soluble Amine Salt of a Phosphorus Compound , published September 18, 1984.

11 Clark , U.S. Patent No. 4,534,873, Automotive Friction Reducing Composition , published August 13, 1985.

12 Brewster , U.S. Patent No. 3,489,619, Heat Transfer and Quench Oil , published January 13, 1970.

13 Salentine , U.S. Patent No. 4,717,490, Synergistic Combination of Alkali Metal Borates, Sulfur Compounds, Phosphites and Neutralized Phosphate , published January 5, 1988.

State of the art

Often, high load conditions occur in gears such as those used in transmissions and car differentials, pneumatic tools, gas compressors, centrifuges, high pressure hydraulic systems, metalworking devices and the like, as well as in many types of bearings. When employed in such environments, it is common to add extreme pressure agent (usually abbreviated as EP, by its initials in English: p ressure xtreme- e) to the lubricant composition and, in this regard, alkali metal borates are well known as extreme pressure agents for said compositions 1-11,13.

E.P. agents are added to the lubricants to avoid destructive metal-to-metal contact in the lubrication of moving surfaces. Under normal conditions, called "hydrodynamics", a film of lubricant between surfaces that move relatively controlled by lubricant parameters, and mainly by viscosity However, when the load is increased, the gap between surfaces decreases or when moving surface speeds is such that the film of oil cannot be maintained, the condition of "limit lubrication", mainly controlled by parameters of the surfaces in contact. In conditions still more severe, significant destructive contact of various forms, such as wear and fatigue of the metal, measured by the grooves and bites. The role of E.P. Is to avoid Let this happen. In most cases, E.P. they are oil soluble or easily dispersible as a dispersion stable in oil and are mainly organic compounds that have been chemically reacted to contain sulfur, halogens (mainly chlorine), phosphorus, carboxyl groups or carboxylate salt groups that react with the surface of the metal in limit lubrication conditions. It has also found that stable dispersions of metal borates Alkaline are effective as agents of E.P.

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

In addition, agents are often used anti-seize in the gearboxes of cars for Provide smooth synchronization and good changeability. Examples of such anti-seize agents include phosphates, phosphites, phosphonates, thiophosphates, carbamates and dithiocarbamates and molybdenum dithiophosphates.

It is also known that boron nitride has friction modifying properties in lubricants. By For example, U.S. Patent No. 4,787,993, published on 29 November 1988 by Nagahiro, describes an effective lubricant for friction reduction comprising dispersing a resin of finely powdered polyamide or aromatic in a fluid grease or oil, which may additionally contain disulfide of molybdenum, an organic compound with molybdenum or nitride of boron.

In addition, U.S. Patent No. 4,715,972, published on December 29, 1987 by Pacholke, describes a solid lubricant additive for gear oils comprising solid lubricating particles combined with an agent stabilizer and a fluid vehicle, in which the particles solid lubricants are chosen 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, zinc sulfide, fluorinated carbon, PTFE, graphite interleaved, zinc phosphide, zinc phosphate and mixtures thereof. This patent further describes that said lubricant additive provides the gear oil with demulsibility characteristics, improved stability and compatibility for the oil for gears when contaminated with water.

Consequently, it is an objective of the present invention provide a lubricant additive composition that have good anti-seize properties when used in oils of transmission.

Summary of the Invention

The present invention provides a New additive composition for a transmission oil, which understands:

(a) an oily dispersion of a metal borate hydrated alkaline, and

(b) an oily dispersion of boron nitride hexagonal;

in which the weight ratio between Hydrated alkali metal borate and hexagonal boron nitride is in the range of 95: 5 to 5:95

The additive composition of the present invention can be suitably employed in both oils for manual transmission changes as in transmission oils automatic Preferably, the additive composition will be employed in an oil for manual transmission changes.

The present invention further provides a lubricating oil composition comprising an amount important of a lubricating viscosity transmission oil and an effective amount to reduce seizure of the synchronizer of the additive composition described above. Preferably, the transmission oil is an oil for manual transmission gears.

Among other factors, the present invention is based in part on the surprising discovery that the unique combination of an oily dispersion of a metal borate hydrated alkaline and an oily dispersion of boron nitride hexagonal provides a significant and unexpected reduction of seizing of the synchronizer when used as a composition of additive in an oil for manual transmission changes.

Detailed description of the invention

As indicated above, this invention refers to a new additive composition for a transmission oil comprising (a) an oily dispersion of a hydrated alkali metal borate, and (b) an oily dispersion of hexagonal boron nitride, in which the weight ratio between the alkali metal borate and hexagonal boron nitride is in the 95: 5 to 5:95 interval.

Typically, the oily dispersion of borate from Hydrated alkali metal will contain an alkali metal borate hydrated, a dispersant, optionally a detergent and an oil of lubricating viscosity. Preferably, the dispersant employed in the oily dispersion of hydrated alkali metal borate it choose from the group consisting of a polyalkylene succinimide, a polyalkylene succinic anhydride, a polyalkylene succinic acid, a mono- or disal of a polyalkylene succinic acid, and mixtures thereof. Optionally, the oily dispersion of alkali metal borate hydrated will also contain a detergent, such as a sulphonate metallic, preferably an alkylaromatic calcium sulphonate or another sulphonate of a Group II metal that acts here compositions to help provide a dispersion homogeneous

The oily dispersion of alkali metal borate hydrated preferably includes those compositions that comprise 10 to 75 percent by weight of metal borate hydrated alkaline; from 2 to 40 percent by weight of a dispersant; and from 30 to 70 percent by weight of an oil of viscosity lubricant; all with respect to the total weight of the dispersion Oily

Each of the components of the composition of additive of the present invention will be described in more detail in the next part of this specification.

Hydrated alkali metal borate

Hydrated alkali metal borates are well known in the art. Representative patents that describe  Suitable borates and processing methods include patents U.S. No. 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 may be represented by the following general formula:

M_ {2} O \ cdotxB_ {2} O_ {3} \ cdotyH_ {2} O

in which M is an alkali metal, preferably sodium or potassium, x is a number from 2.5 to 4.5 (both integers as fractional), and y is a number from 1.0 to 4.8. They are more preferred hydrated potassium borates, particularly those hydrated potassium triborates. Borate Particles hydrated will generally have a smaller average particle size that 1 micron.

In the alkali metal borates used in this invention, the relationship between boron and alkali metal it will preferably vary from 2.5: 1 to 4.5: 1.

Oily dispersions of metal borates Hydrated alkalis are usually prepared by making, in water deionized, a solution of alkali metal and acid hydroxide boric, optionally in the presence of a small amount of the corresponding alkali metal carbonate. The solution is added then to a lubricating composition comprising an oil of lubricating viscosity, a dispersant and any additive optional that should be included in it (for example, a detergent or another optional additive) to form an emulsion that then dehydrates

Due to its retention of hydroxyl groups in the borate complex, these complexes are called "borates of hydrated alkali metal "and the compositions containing oil / water emulsions of these alkali metal borates hydrates are called "oily dispersions of metal borates alkaline hydrated. "

Oily dispersions of metal borates Preferred alkaline will have a relationship between boron and metal alkaline from 2.5: 1 to 4.5: 1. In another preferred embodiment, the hydrated alkali metal borate particles will have generally an average particle size less than 1 micron. In this aspect, it has been found that alkali metal borates hydrates employed in this invention will preferably have a particle size in which 90% or more of the particles have less than 0.6 microns.

In the oily dispersion of metal borate Hydrated alkaline, hydrated alkali metal borate will generally comprise from 10 to 75 percent by weight, preferably from 25 to 50 percent by weight, more preferably from 30 to 40 percent by weight with respect to the total weight of the oily dispersion of hydrated borate. (Unless indicated by otherwise, all percentages are percentages by weight).

Additive compositions and compositions lubricants of this invention may also employ surfactants, detergents, other dispersants and other conditions as described below and is known to those skilled in the art. Optionally, the additive compositions contain a sulphonate alkylaromatic or a polyisobutenylsulfonate.

Oily dispersions of metal borates alkaline hydrates employed in this invention comprise generally a dispersant, an oil of lubricating viscosity and optionally a detergent, which are further detailed then.

The dispersant

The dispersant used in the oil dispersion of hydrated alkali metal borate used in this invention can be a dispersant without ashes, such as an alkenyl succinimide, a alkenyl succinic anhydride, an alkenyl succinate ester and similar or mixtures of said dispersants.

Ashless dispersants are divided into general lines in several groups. One of these groups refers to copolymers containing a carboxylate ester with one or more additional polar functional groups, including amine, amide, imine, imide, hydroxyl, carboxyl and the like. These products can be prepared by copolymerization of acrylates or long chain alkyl methacrylates with monomers having the previous functional groups. Such groups include copolymers. alkyl vinyl pyrrolidinone methacrylate, alkyl methacrylate methacrylate copolymers of dialkylaminoethyl and the like. Additionally, they can be used esters and polyesters or high weight polyamides and amides molecular, such as tetraethylenepentamine, polyesterates polyvinyl and other polyesteramides. Preferred dispersants are long chain alkenyl succinimides N-substituted

Alkenyl succinimides are obtained generally from the acid or anhydride reaction alkenyl succinic with alkylene polyamines. It is generally considered that these compounds have the formula:

one

in which R1 is essentially a hydrocarbon radical having a molecular weight of 400 to 3,000, that is, R1 is a hydrocarbyl radical, preferably an alkenyl radical, containing from 30 to 200 carbon atoms; Alk is an alkylene radical of 2 to 10, preferably from 2 to 6, carbon atoms; R2, R3 and R 4 are chosen from an alkyl or alkoxy C 1 -C 4 or hydrogen, preferably hydrogen, and x is an integer from 0 to 10, preferably 0 to 3. Actually, the reaction product of the acid or anhydride alkylene succinic and alkylene polyamine will comprise a mixture of compounds that include succinamic acids and succinimides. Without However, it is customary to refer to this reaction product as a succinimide of the indicated formula since this will be the main component of the mixture. See, for example, patents U.S. 3,202,678, 3,024,237 and 3,172,892.

These alkenyl succinimides N-substituted can be prepared by reacting maleic anhydride with an olefinic hydrocarbon, followed by reaction of the resulting alkenyl succinic anhydride with the alkylene polyamine. The radical R 1 of the above formula is say the alkenyl radical, is preferably obtained from a polymer prepared from an olefinic monomer containing from 2 to 5 carbon atoms. Therefore, the alkenyl radical is obtained by polymerizing an olefin containing from 2 to 5 atoms of carbon to form a hydrocarbon that has a molecular weight that It varies from 400 to 3,000. Examples of such olefinic monomers are the ethylene, propylene, 1-butene, 2-butene, isobutene and mixtures thereof.

Preferred polyalkyleneamines used for Prepare succinimides have the formula:

2

where x is an integer of 0 to 10 and Alk, R2, R3 and R4 are as defined previously.

Alkyleneamines mainly include methylenamines, ethyleneamines, butylenamines, propyleneamines, pentylenamines, hexylenamines, heptylenamines, octylenamines, others polymethylenamines and also cyclic and higher homologs of said amines, such as piperazine and aminopiperazines substituted with alkyl. Specific examples are ethylenediamine, triethylene tetraamine, propylenediamine, decamethyldiamine, octamethylenediamine, diheptamethylenetriamine, tripropyltratramine, tetraethylenepentaamine, trimethylene diamine, pentaethylenehexamine, dithrimethylenetriamine, 2-heptyl-3- (2-aminopropyl) -imidazoline, 4-methylimidazoline, N, N-dimethyl-1,3-propanediamine, 1,3-bis (2-aminoethyl) imidazoline,  1- (2-aminopropyl) -piperazine, 1,4-bis (2-aminoethyl) piperazine Y 2-methyl-1- (2-aminobutyl) piperazine. Also useful are higher homologues, such as those obtained by condensing two or more of the indicated alkylenamines previously.

Ethylenamines are especially useful. They are described in some detail in the heading "Ethylene Amines" in the Encyclopedia of Chemical Technology , Kirk-Othmer, Vol. 5, p. 898-905 (Interscience Publishers, New York, 1950).

The term "ethylenamine" is used in a generic sense to indicate a type of polyamines that fit mostly to the structure:

H 2 N (CH 2 CH 2 NH) a H

in which a is an integer of 1 a 10.

Therefore, for example the ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylene pentaamine, pentaethylenehexaamine and the like.

Also included in the term "alkenyl succinimides" are succinimides with subsequent treatments, such as post-treatment procedures involving ethylene carbonate and which have been described by Wollenberg et al. , U.S. Patent No. 4,612,132 and Wollenberg et al. , US Patent No. 4,746,446, as well as other post-treatment procedures.

Preferably, the dispersant component, such as a polyalkylene succinimide, it comprises 2 to 40 percent in weight, more preferably 5 to 20 percent by weight and even more preferably 5 to 15 percent by weight, based on weight total oil dispersion of alkali metal borate hydrous.

They are also suitable dispersants for use in the compositions of this invention anhydrides polyalkylene succinic or a derivative that does not contain nitrogen from a polyalkylene succinic anhydride (such as succinic acids, the mono- or disal of Group I and / or Group II of acids succinic, succinate esters formed by the reaction of a polyalkylene succinic anhydride, acid chloride and other derivatives with an alcohol and the like).

The polyalkyl succinic anhydride is preferably an anhydride poly-isobutenylsuccinic. In one embodiment preferred, the polyalkyl succinic anhydride is an anhydride poly-isobutenylsuccinic having a weight average molecular number of at least 500, more preferably of at at least 900 to 3,000 and even more preferably at least 900 to 2,300.

In another preferred embodiment, a mixture of polyalkylene succinic anhydrides is used. 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 at least 500 to less than 1,000 and the high molecular weight component has a number average molecular weight of 1,000 to 3,000. Even more preferably, both low and high molecular weight components are polyisobutenyl succinic anhydrides. Alternatively, polyalkylene succinic anhydride components of different molecular weights can be combined as a dispersant, as well as a mixture of the other dispersants mentioned and identified above.
mind.

As indicated above, the anhydride polyalkylene succinic is the product of the reaction of a polyalkylene (preferably polyisobutene) with maleic anhydride In the preparation of said anhydrides polyalkylene succinic poly-isobutene can be used conventional or a methylvinylidenpoli-isobutene. In this preparation can be used thermal procedures, of chlorination, free radicals, acid catalyzed or any other procedure Examples of polyalkylene succinic anhydrides suitable are PIBSA (anhydride poly-isobutenylsuccinic) thermally obtained described in U.S. Patent No. 3,361,673; the PIBSA obtained by chlorination described in US Patent No. 3,172,892; a mixture of PIBSA thermally obtained and obtained by chlorination described in US Patent No. 3,912,764; he PIBSA with a high succinic ratio described in the patent U.S. No. 4,234,435; the poly-PIBSA described in U.S. Patent Nos. 5,112,507 and 5,175,225; poly-PIBSA with high succinic ratio described in U.S. Patent Nos. 5,565,528 and 5,616,668; PIBSA obtained through a free radical procedure described in U.S. Patent Nos. 5,286,799, 5,319,030 and 5,625,004; PIBSA made from methylvinylidene-polybutene described in the patents U.S. 4,152,499, 5,137,978 and 5,137,980; the PIBSA of high succinic ratio developed from a methylvinyliden-superior polybutene described in the European Patent Application Publication No. EP 355,895; the PIBSA terpolymer described in US Patent No. 5,792,729: the PIBSA of sulfonic acid described in US Patent No. 5,777,025 and in European Patent Application Publication No. EP 0542380; and the purified PIBSA described in US Pat. No. 5,523,417 and in European Patent Application Publication No. EP 0602863.

Preferably, the anhydride polyalkylene succinic or other dispersing component comprises from 2 to 40 percent by weight, more preferably 5 to 20 percent in weight and even more preferably 5 to 15 percent by weight, with respect to the weight of the oily dispersion of metal borate hydrated alkaline

Generally, in the oily dispersion of borate Hydrated alkali metal, hydrated alkali metal borate is in a ratio of at least 2: 1 with respect to the anhydride polyalkylene succinic or other dispersant, preferably being in the range of 2: 1 to 10: 1. In one more embodiment preferred the ratio is at least 5: 1. In another way of preferred embodiment mixtures of anhydrides are used polyalkylene succinic as described above.

The detergent

The oily dispersion of alkali metal borate hydrate employed in the additive compositions herein The invention may optionally contain a detergent. There are several materials that are suitable as detergents for the purpose of this invention. These materials include phenates (with an excess large alkali metal or a small excess of alkali metal, Phenosterates with a large excess of alkali metal, phenolates, salicylates, phosphonates, thiophosphonates and sulphonates and mixtures thereof. Preferably sulfonates are used, such as sulfonates with a large excess of alkali metal, sulphonates with a small excess of alkali metal or phenoxysulfonates. In addition they can also be used the same sulfonic acids.

The sulphonate detergent is preferably a salt with an alkali metal or alkaline earth metal of an acid hydrocarbylsulfonic acid having 15 to 200 carbon atoms. Preferably the term "sulfonate" includes the salts of the sulfonic acid obtained from petroleum products. Such acids are well known in the art. Can be obtained treating petroleum products with sulfuric acid or trioxide Sulfur Acids obtained in this way are known as petroleum sulfonic acids and salts such as sulfonates from Petroleum. Most petroleum products that can be convert into sulfonates contain a hydrocarbon group that increases oil solubility. They are also included in the meaning of "sulfonate" salts of sulfonic acids with synthetic alkylaryl compounds. These acids are prepared also treating a alkylaryl compound with sulfuric acid or with sulfur trioxide. At least one alkyl substituent of the ring aryl is a group that increases oil solubility, as has been indicated above. The acids obtained in this way are known as alkylarylsulfonic acids and salts as alkylarylsulfonates. Sulfonates in which alkyl is a linear chain are the well known alkylarylsulfonates linear

The acids obtained by sulfonation are converted into metal salts by neutralization with a basic reactive compound of an alkali metal or alkaline earth metal to give the metal sulphonates of Group I or Group II. Generally, acids are neutralized with a metal base alkaline. The alkaline earth metal salts are obtained from of the alkali metal salt by transposition. Alternatively, the sulfonic acids can be neutralized directly with a base of alkaline earth metal. Then you can make the sulfonates have an excess of alkali metal, although for Objectives of the present invention do not require an excess of alkali metal Materials with excess alkali metal and methods for preparing such materials are well known to experts in the art. See, for example, LeSuer, patent U.S. No. 3,496,105, published February 17, 1979, particularly columns 3 and 4.

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

However, they are particularly preferred, Due to its wide availability, acid salts sulfonic petroleum, particularly sulfonic acids of the oil obtained by sulfonation of several fractions of hydrocarbons, such as fractions of lubricating oil and extracts rich in aromatic compounds that are obtained by extraction of hydrocarbon oil with a selective solvent, whose extracts can, if desired, be rented before the sulfonation by reacting them with olefins or with chlorides of alkyl by means of an alkylation catalyst; the acids organic polysulfonic acids, such as becenedisulfonic acid, that may be rented or not; and the like

Preferred salts for use herein invention are those of alkylated aromatic sulfonic acids in the that the alkyl radical or radicals contain at least 8 atoms of carbon, for example from 8 to 22 carbon atoms. Another group Preferred sulfonate starting materials are acids aliphatically substituted cyclic sulfonic acids in which the substituents or aliphatic substituents contain a total of at minus 12 carbon atoms, such as acids alkylarylsulfonic, alkylcycloaliphatic sulfonic acids, alkylheterocyclic sulfonic acids and sulfonic acids aliphatic 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 acids petroleum sulfonic acids, mono- and naphthalenesulfonic acids polysubstituted with waxes, substituted sulfonic acids, such such as cetylbenzenesulfonic acids, cetylphenylsulfonic acids and the like, aliphatic sulfonic acids, such as acids paraffin wax sulfonic, paraffin wax sulfonic acids substituted with hydroxy, etc., sulfonic acids cycloaliphatic, petroleum naphthalenesulfonic acids, acid cetylcyclopentylsulfonic acid, mono- and cyclohexylsulfonic acids polysubstituted with waxes and the like. The expression "acids sulfonic petroleum "aims to include all acids sulphonics that are obtained directly from products of the Petroleum.

Typical Group II Metal Sulphonates Suitable for use in the present invention include the metal sulphonates whose examples are as follows: white oil calcium benzenesulfonate, benzenesulfonate white oil barium, magnesium benzenesulfonate oil white, calcium dipolipropenebenzenesulfonate, barium dipolipropenobenzenesulfonate, magnesium dipolipropenobenzenesulfonate, calcium sulphonate mahogany oil, barium sulfonate mahogany oil, Petroleum Mahogany Magnesium Sulfonate, Triacontylsulfonate calcium, magnesium triacontylsulfonate, calcium lauryl sulphonate, barium lauryl sulphonate, magnesium lauryl sulphonate, 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. However, when it is present, the detergent concentration will generally vary from 0.2 to 10 percent by weight and preferably 3 to 7 percent in weight, with respect to the total weight of the oil dispersion of borate hydrous. In addition, the compositions of this invention may contain a mixture of a metal sulphonate and a dispersant without ashes, as described above, in which the relationship is a factor to obtain the appropriate stability of the dispersion Hydrous alkali metal borate oil.

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Lubricating viscosity oil

The lubricating oil to which borate is added of hydrated alkali metal and the dispersant to form the Oily dispersion of hydrated alkali metal borate can be any hydrocarbon-based lubricating oil or a stockpile of synthetic base oil Similarly, these oils lubricants can be added to the oily dispersion of borate from hydrated alkali metal and additive compositions that they contain, as described above, in quantities additional to make the finished oily compositions. The hydrocarbon-based lubricating oils can be obtained at from synthetic or natural sources and can be based paraffinic, naphthalene or aromatic, or mixtures thereof. Oil diluent can be natural or synthetic and can have different viscosity grades

In the oily dispersion of metal borate hydrated alkaline, the lubricating oil generally comprises of 30 to 70 percent by weight, more preferably 45 to 55 percent weight percent, with respect to the total weight of the oil dispersion of hydrated alkali metal borate.

In general, the oily dispersion of borate from Hydrated alkali metal is present in the additive composition of the invention in the range of 10 to 90 percent by weight, with with respect to the total weight of the additive composition.

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The oily dispersion of hexagonal boron nitride

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

Hexagonal boron nitride, or h-BN, is a hexagonal, graphite-like form of boron nitride that has a 6-layered flat layer and ring structure of 6 boron atoms and nitrogen alternately. In alternate sheets, the boron atoms are directly above the nitrogen atoms. Hexagonal boron nitride can be prepared by heating boric oxide, boric acid or salts of boric acid with ammonium chloride, alkaline cyanides or calcium cyanamide at atmospheric pressure. Hexagonal boron nitride can also be prepared by reacting boron trichloride or boron trifluoride with ammonia. A discussion of hexagonal boron nitride can be found, for example, in Kirk-Obmer, Encyclopedia of Chemical Technology , fourth edition, Vol. 4, p. 427-429, John Wiley and Sons, New York, 1992.

Generally hexagon boron nitride will have an average particle size of less than 1 micron. Preferably the hexagon boron nitride will have a size distribution of particle in which 90% or more of the particles are less than approximately 0.5 microns (500 nanometers, nm), with a size preferred particle medium of less than about 0.3 microns (300 nm).

Typically, the oily nitride dispersion of hexagonal boron will contain 1 to 50 percent by weight of nitride of hexagonal boron, preferably 1 to 20 percent by weight and more preferably 5 to 15 percent by weight, with respect to the Total weight of the oil dispersion.

Preferably, the oil dispersion of the hexagon boron nitride will contain a surfactant such as oil dispersion stabilizer. Typical surfactants for be used as stabilizers include copolymers of ethylene-propylene or terpolymers of ethylene, propylene and an unconjugated diene, generally referred to as terpolymers of ethylene-propylene-diene, copolymers ethylene-propylene grafted with a group functional vinyl containing nitrogen chosen from the group that consists of N-vinyl pyrrolidone and N-vinylpyridine, and the like. The copolymer of ethylene-propylene generally has a weight Average molecular in the range of 22,000 to 200,000. A Preferred surfactant is a copolymer of ethylene-propylene which has essentially the same proportions of ethylene and propylene monomers and a weight Average molecular weight of 22,000 to 40,000. When present, the concentration of surfactant in the oily dispersion of nitride of hexagonal boron will generally vary from 0.1 to 25 percent by weight, preferably from 2 to 7 percent by weight and more preferably from 3.0 to 5.0 percent by weight, based on the total weight of the oily dispersion of hexagonal boron nitride.

The lubricating oil used to prepare the oily dispersion of hexagonal boron nitride can be chosen between the same group of natural or synthetic lubricating oils described above for use in the oil dispersion of hydrated alkali metal borate, but it has been found that also other fluid vehicles can be satisfactory, including vegetable oils such as rapeseed oil; liquid hydrocarbons, such as aliphatic and aromatic naphtha and their mixtures; synthetic lubricating fluids, such as polyalphaolefins, polyglycols, diester fluids and mixtures of these liquids In addition, the oil used to make the dispersion Hexagonal boron nitride oil can be the same or different that the lubricating oil used in the preparation of the dispersion Hydrous alkali metal borate oil. Typical oils for the preparation of the oily dispersion of hexagonal boron nitride include oils with Group I and Group II bases, such as 150 neutral solvent oil oil.

In general, the oily dispersion of nitride from hexagonal boron is present in the additive composition of the invention in the range of 10 to 90 percent by weight, with with respect to the total amount of the additive composition.

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Formulations

The additive compositions herein invention containing oily dispersions of metal borate alkaline and hexagonal boron nitride (as described in the previous part of this report) can also be mixed with additional additives to make additive packages containing The present additive composition. Those additive packages they generally comprise from 10 to 80 percent by weight of the additive composition of the present invention described above and 90 to 20 percent by weight of one or more additives Conventionals chosen from the group consisting of dispersants without ashes (0-10%), detergents (0-5%), sulfur hydrocarbons (0-40%), dialkyl hydrogen phosphates (0-15%), zinc dithiophosphates (0-20%), phosphates and / or thio- or dithiophosphates of alkylammonium (0-20%), phosphites (0 to 10%), esters of  fatty acids with polyols (0-10%), 2,5-dimercaptotiadizol (0-5%), benzotriazole (0-5%), molybdenum disulfide dispersed (0-5%), foam inhibitors (0-2%) and imidazolines (0-10%) and similar, each percentage by weight being referred to the total weight of the composition.

The fully finished oily compositions and formulated from this invention can be formulated from these additive packages by additional mixing with an oil of lubricating viscosity Preferably the additive package described above is added to a lubricating viscosity oil in an amount of 1 to 20 percent by weight, preferably 2 at 15 percent by weight, to provide the oil composition finished, the percentage by weight of the additive package being referred to the total weight of the composition.

Other different additives may be present in the lubricating oils of the present invention. These additives include antioxidants, oxidation inhibitors, inhibitors of corrosion, extreme pressure agents, antifoam agents, others antiwear agents and several other additives well known in the technique.

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Examples

The invention will be further illustrated. by the following examples describing embodiments particularly advantageous. The examples are provided for illustrate the present invention and are not intended to limit it.

Example 1

The additive composition of the present invention was evaluated in a lubricating oil analyzing its anti-seize properties following a test using a bank SAE Nº 2 and that evaluates the transmission fluids during the synchronization. The friction pairs used in this bench they comprise a brass synchronizer ring and a pinion cone of steel.

During each cycle of the test, the cone is rotating at a given speed, then the ring moves along of the cone shaft for braking until it locks. At the end of Each cycle the ring separates.

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

The anti-seize coefficient for this trial was calculated as follows:

coefficient of anti-seize = 1 - \ frac {(N o} \ of \ cycles \ with \ seizure)} {(N ^ {\} \ total \ of \ cycles \ en \ el \ test)}

Consequently, a coefficient of anti-seize of 0 indicates the presence of seizure of the cone in the ring during each test cycle. Conversely, a anti-seize coefficient of 1 indicates that it was not observed No seizure for the entire duration of the test. For the so much, the higher the anti-seize coefficient, up to a maximum of 1, the better the anti-seize properties of the lubricant oil.

The lubricating oil compositions for the Assay were formulated as indicated below.

Lubricant composition 1

A lubricant composition was prepared which It contained the following:

(to)

7 weight percent of an oily dispersion of potassium triborate hydrated, in which the oil dispersion contained approximately 30 percent by weight of dispersed hydrated potassium triborate in a neutral oil 150 N;

(b)

10 weight percent of an oily dispersion of boron nitride hexagonal, in which the oil dispersion contained approximately 10 percent by weight of hexagonal boron nitride solids dispersed in a 150 N neutral oil containing an agent stabilizer; Y

(C)

83 weight percent of a 50/50 mixture of neutral oil (150 N more 600 N) and a synthetic polyalphaolefin oil.

Lubricant composition 2

A lubricant composition 2 was prepared which It contained the following:

(to)

7 weight percent of an oily dispersion of potassium triborate hydrated, in which the oil dispersion contained approximately 30 percent by weight of dispersed hydrated potassium triborate in a neutral oil 150 N;

(b)

5 weight percent of an oily dispersion of boron nitride hexagonal, in which the oil dispersion contained approximately 10 percent by weight of hexagonal boron nitride solids dispersed in a 150 N neutral oil containing an agent stabilizer; Y

(C)

88 weight percent of a 50/50 mixture of neutral oil (150 N more 600 N) and a synthetic polyalphaolefin oil.

Lube Composition 3

A lubricating composition 3 was prepared which It contained the following:

(to)

7 weight percent of an oily dispersion of potassium triborate hydrated, in which the oil dispersion contained approximately 30 percent by weight of dispersed hydrated potassium triborate in a neutral oil 150 N;

(b)

2.5 weight percent of an oily dispersion of boron nitride hexagonal, in which the oil dispersion contained approximately 10 percent by weight of hexagonal boron nitride solids dispersed in a 150 N neutral oil containing an agent stabilizer; Y

(C)

90.5 weight percent of a 50/50 mixture of neutral oil (150 N more 600 N) and a synthetic polyalphaolefin oil.

Lubricant composition A (comparative)

A lubricant composition was prepared which It contained the following:

(to)

7 weight percent of an oily dispersion of potassium triborate hydrated, in which the oil dispersion contained approximately 30 percent by weight of dispersed hydrated potassium triborate in a neutral oil 150 N; Y

(b)

93 weight percent of a 50/50 mixture of neutral oil (150 N more 600 N) and a synthetic polyalphaolefin oil.

Lubricant composition B (comparative)

A lubricant composition was prepared which It contained the following:

(to)

10 weight percent of an oily dispersion of boron nitride hexagonal, in which the oil dispersion contained approximately 10 percent by weight of hexagonal boron nitride solids dispersed in a 150 N neutral oil containing an agent stabilizer; Y

(b)

90 weight percent of a 50/50 mixture of neutral oil (150 N more 600 N) and a synthetic polyalphaolefin oil.

The characteristics of anti-seize in the previous lubricant compositions in the synchronization test described above. It was also tested a base oil containing a 50/50 mixture of 150 N neutral oil and 600 N, without additives. The results of this evaluation are shown. in table I.

TABLE I

3

The above data show that the Additive composition of the present invention provides significant anti-seize characteristics and show a notable improvement over comparative compositions.

Claims (17)

1. An additive composition for an oil of transmission comprising:

(to)

a oil dispersion of a hydrated alkali metal borate, Y

(b)

a oily dispersion of hexagonal boron nitride;

in which the weight ratio between Hydrated alkali metal borate and hexagonal boron nitride is in the range of 95: 5 to 5:95

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2. The composition of additive according to claim 1, wherein the alkali metal in the metal borate Hydrated alkaline is sodium or potassium. 3. The composition of additive according to claim 2, wherein the alkali metal is potassium. 4. The composition of additive according to claim 3, wherein the hydrated alkali metal borate is  hydrated potassium triborate. 5. The composition of additive according to claim 1, wherein the oily dispersion of metal borate Hydrated alkaline contains a hydrated alkali metal borate, a dispersant and an oil of lubricating viscosity. 6. The composition of additive according to claim 5, wherein the oily dispersion of metal borate Hydrated alkaline contains 10 to 75 percent by weight of borate of hydrated alkali metal, with respect to the total weight of the oil dispersion 7. The composition of additive according to claim 5, wherein the oily dispersion of metal borate Hydrated alkaline contains 2 to 40 percent by weight of dispersant, with respect to the total weight of the oil dispersion. 8. The composition of additive according to claim 5, wherein the oily dispersion of metal borate Hydrated alkaline additionally contains a detergent. 9. The composition of additive according to claim 8, wherein the oily dispersion of metal borate Hydrated alkaline contains 0.2 to 10 percent by weight of detergent, with respect to the total weight of the oil dispersion. 10. The composition of additive according to claim 1, wherein the oily dispersion of metal borate Hydrated alkaline is present in the additive composition in the range of 10 to 90 percent by weight, based on total weight of the additive composition. 11. The additive composition according to claim 1, wherein the hexagonal boron nitride has a particle size distribution in which 90% or more of the particles are less than about 0.5 micro-
nes. 12. The composition of additive according to claim 1, wherein the oily dispersion of boron nitride Hexagonal contains an oil of lubricating viscosity and 1 to approximately 50 weight percent hexagonal boron nitride, with respect to the total weight of the oil dispersion. 13. The composition of additive according to claim 12, wherein the oily dispersion of boron nitride  hexagonal additionally contains a surfactant as stabilizer 14. The composition of additive according to claim 1, wherein the oily dispersion of boron nitride hexagonal is present in the additive composition in the range 10 to 90 percent by weight, based on the total weight of the additive composition 15. A lubricating oil composition that it comprises a significant amount of a transmission oil of lubricating viscosity and an effective amount to reduce the seizing of the synchronizer of an additive composition that understands:

(to)

a oil dispersion of a hydrated alkali metal borate, Y

(b)

a oily dispersion of hexagonal boron nitride;

in which the weight ratio between Hydrated alkali metal borate and hexagonal boron nitride is in the range of 95: 5 to 5:95

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16. The lubricating oil composition according to the claim 15, wherein the lubricating oil composition contains from 1 to 20 percent by weight of the additive composition, with respect to the total weight of the oil composition lubricant. 17. The lubricating oil composition according to the claim 15, wherein the transmission oil is an oil for manual transmission changes.