JP4391937B2 - Additive composition for transmission oil comprising hydrated alkali metal borate and hexagonal boron 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

  The present invention relates to an additive composition for transmission oil. In particular, the present invention relates to an additive composition comprising an oil dispersion of hydrated alkali metal borate and an oil dispersion of hexagonal boron nitride, and a lubricating oil composition containing it.

  Gear sets such as those used in automotive transmissions and differentials, pneumatic tools, gas compressors, centrifuges, high pressure hydraulic equipment, metalworking and similar equipment, and many types of bearings are often high. A load condition has occurred. When lubricant compositions are used in such environments, extreme pressure (EP) agents have traditionally been added, in which alkali metal borates are well known as extreme pressure agents for such compositions. (Patent Documents 1 to 11, 13). The EP agent is added to the lubricant to prevent destructive metal-metal contact in moving surface lubrication. On the other hand, in a normal state, referred to as “hydrodynamic”, a thin film of lubricant is maintained between the relatively moving surfaces governed by the lubricant parameters, mainly viscosity. However, if the load increases, the gap between the surfaces decreases, or the speed of the movable surface is such that the oil film cannot be maintained, reaching a “boundary lubrication” condition and is largely governed by the contact surface parameters. In even more severe conditions, significant destructive contact is manifested in various forms, such as wear and metal fatigue, measured as ridge and pitting. It is the role of the EP additive to avoid this happening. EP agents are usually oil-soluble or easily dispersible in oil as stable dispersions, and are mostly chemically reacted organic compounds that react with metal surfaces in boundary lubrication conditions, mainly sulfur, halogens (mainly Chlorine), phosphorus, carboxyl or carboxylate groups. Stable dispersions of hydrated alkali metal borates have also been found to be effective as EP agents.

  Also, since the hydrated alkali metal borate is insoluble in the lubricating oil medium, it is necessary to mix the borate with the oil as a dispersion, and a homogeneous dispersion is particularly desirable. The degree of formation of a homogeneous dispersion can be correlated with the turbidity of the oil after addition of the hydrated alkali metal borate, and the higher the turbidity, the lower the homogeneity of the dispersion. In order to facilitate the formation of such a homogeneous dispersion, it has been conventionally practiced to include a dispersant in such a composition. Examples of the dispersant include lipophilic surfactants such as alkenyl succinimide, or other nitrogen-containing dispersants, and alkenyl succinate (Patent Documents 1 to 4, 12). In order to facilitate the formation of a homogeneous dispersion, it is also conventional to use an alkali metal borate having a particle size of 1 micron or less (Patent Document 11).

  In addition, anti-sticking agents are often used in automobile gearboxes to provide smooth synchronization and good transmission. Examples of such antiblocking agents include phosphate esters, phosphites, phosphonates, thiophosphates, carbamates, molybdenum dithiocarbamates and molybdenum dithiophosphates.

  It is also known that boron nitride exhibits friction relaxation properties in lubricants. For example, Patent Document 14 discloses that a fine powdery aromatic or polyamide resin is dispersed in liquid fat or oil, and may further contain molybdenum disulfide, organic molybdenum, or boron nitride, which is effective for reducing friction. Specific lubricants are disclosed.

  Further, Patent Document 15 discloses a solid lubricant additive for gear oils in which solid lubricant particles are combined with a stabilizer and a liquid carrier, and the solid lubricant particles include molybdenum disulfide, graphite, cerium fluoride. , Zinc oxide, tungsten disulfide, mica, boron nitrate, boron nitride, borax, silver sulfate, cadmium iodide, lead iodide, barium fluoride, tin sulfide, fluorinated carbon, PTFE, insertion graphite, phosphorous acid Selected from the group consisting of zinc, zinc phosphate and mixtures thereof. This patent further discloses that such lubricant additives, when incorporated with water, provide gear oils with improved demulsibility, stability and mixing characteristics of gear oils.

  In this application, the following references are numbered and cited:

US Pat. No. 3,133,727, Peeler, “Alkali Metal Borate EP Lubricant”, issued April 11, 1967 U.S. Pat. No. 3,912,463, Adams, “Lubricant containing neutralized alkali metal borate”, issued on October 14, 1975 U.S. Pat. No. 3,819,521, Sims, "Lubricant with Dispersed Borate and Polyol", issued June 25, 1974 U.S. Pat. No. 3,853,772, Adams, "Lubricant containing alkali metal borate dispersed with a mixture of dispersants", issued December 10, 1974 US Pat. No. 3,997,454, Adams, “Lubricant containing potassium borate”, issued December 14, 1976 US Pat. No. 4,089,790, Adams, “Synergistic combination of hydrated potassium borate, antiwear agent and organic sulfide antioxidant”, issued May 16, 1978. U.S. Pat. No. 4,163,729, Adams, "Synergistic combination of hydrated potassium borate, antiwear and organic sulfide antioxidant", issued August 7, 1979 US Pat. No. 4,263,155, Frost, “Lubricant Composition Containing Alkali Metal Borate and Stabilized Oil-Soluble Acid”, issued April 21, 1981 U.S. Pat. No. 4,401,580, Frost, "Lubricant Composition Containing Alkali Metal Borate and Ester-Polyol Compound", issued August 30, 1983 U.S. Pat. No. 4,472,288, Frost, "Lubricant composition comprising an alkali metal borate and an oil-soluble amine salt of a phosphorus compound", issued on September 18, 1984 U.S. Pat. No. 4,534,873, Clark, "Friction reducing composition for automobiles", issued on August 13, 1985 US Pat. No. 3,489,619, Brewster, “Heat medium quenching oil”, issued January 13, 1970 U.S. Pat. No. 4,717,490, Salentine, "Synergistic combination of alkali metal borates, sulfur compounds, phosphites and neutralized phosphates", published January 5, 1988 US Pat. No. 4,787,993, published by Nagahiro, November 29, 1988 US Pat. No. 4,715,972, Patchoulke, issued December 29, 1987

  All of the above patents are hereby incorporated by reference in their entirety to the same extent that each individual patent was specifically and individually indicated to be fully described as a reference.

  Accordingly, an object of the present invention is to provide a lubricating oil additive composition that exhibits good anti-adhesive properties when used in transmission oil.

The present invention provides a novel additive composition for transmission oil, comprising the following components, wherein the weight ratio of hydrated alkali metal borate to hexagonal boron nitride is in the range of about 95: 5 to about 5:95. I will provide a:
(A) Oil dispersion of hydrated alkali metal borate, and (b) Oil dispersion of hexagonal boron nitride.

  The additive composition of the present invention can be suitably used for both manual transmission gear oil and automatic transmission oil. Preferably, the additive composition of the present invention is used in manual transmission gear oil.

  The present invention also provides a lubricating oil composition comprising a major amount of transmission oil of lubricating viscosity and an effective synchronizer tack reducing amount of the above additive composition. The transmission oil is preferably manual transmission gear oil.

  Among other factors, the present invention includes, as part thereof, an interesting combination of an oil dispersion of hydrated alkali metal borate and an oil dispersion of hexagonal boron nitride. Based on the surprising discovery that when used as a product, it results in a significant and unexpected reduction in synchronizer adhesion.

  As mentioned above, the present invention comprises (a) an oil dispersion of hydrated alkali metal borate, and (b) an oil dispersion of hexagonal boron nitride, and the hydrated alkali metal borate and hexagonal The invention relates to a novel transmission oil additive composition wherein the weight ratio of crystalline boron nitride is in the range of about 95: 5 to about 5:95.

  In general, a hydrated alkali metal borate oil dispersion contains a hydrated alkali metal borate, a dispersant, optionally a detergent, and an oil of lubricating viscosity. Dispersants used in oil dispersions of hydrated alkali metal borates include polyalkylene succinimides, polyalkylene succinic anhydrides, polyalkylene succinic acids, mono or di salts of polyalkylene succinic acids and mixtures thereof. It is preferably selected from the group consisting of Optionally, the hydrated alkali metal borate oil dispersion also contains a detergent, the detergent being, for example, a metal sulfonate, preferably an alkyl aromatic calcium sulfonate, or in the composition of the invention. Other group 2 metal sulfonates that act to help make a homogeneous dispersion.

  The hydrated alkali metal borate oil dispersion includes about 10 to 75% by weight hydrated alkali metal borate, about 2 to 40% by weight dispersant, and about 30 based on the total weight of the oil dispersion. Mention may be made of a composition comprising an oil having a lubricating viscosity of from 70 to 70% by weight.

  Hereinafter, each component of the additive composition of the present invention will be described in more detail.

[Hydrated alkali metal borate]
Hydrated alkali metal borates are well known in the art. Representative patents disclosing suitable borates and methods of preparation include the following: U.S. Pat. Nos. 3,133,727, 3,919,521, 3,853,772, 3,912,463, 3,997,454 and 4,089,790 ( Patent Documents 1 to 6).

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

M ₂ O · xB ₂ O ₃ · yH ₂ O

  Where M is an alkali metal, preferably sodium or potassium, x is a number from 2.5 to 4.5 (which may be an integer or a fraction), and y is from 1.0 to 4.8. Is the number of More preferred is hydrated potassium borate, especially hydrated potassium triborate. The average particle size of the hydrated borate particles is generally 1 micron or less.

  In the alkali metal borates used in the present invention, the ratio of boron to alkali metal is preferably in the range of about 2.5: 1 to about 4.5: 1.

  Hydrated alkali metal borate oil dispersions are generally produced by forming a solution of alkali metal hydroxide and boric acid in deionized water, optionally in the presence of a small amount of the corresponding alkali metal carbonate. The The solution is then added to a lubricating oil composition consisting of an oil of lubricating viscosity, a dispersant, and any optional additive to be included (eg, a detergent or any other additive) and an emulsion. And then dehydrated.

  Because of the hydroxyl groups attached to the borate complexes, these complexes are referred to as “hydrated alkali metal borates” and compositions comprising an oil / water emulsion of these hydrated alkali metal borates Is called “oil dispersion of hydrated alkali metal borate”.

  Preferred hydrated alkali metal borate oil dispersions have a boron to alkali metal ratio of about 2.5: 1 to about 4.5: 1. In another preferred embodiment, the average particle size of the hydrated borate particles is generally 1 micron or less. In this regard, it has been found that the hydrated alkali metal borate used in the present invention preferably has a particle size such that 90% or more of the particles are about 0.6 microns or less.

  In the hydrated alkali metal borate oil dispersion, the hydrated alkali metal borate is generally about 10 to 75% by weight, preferably 25 to 50% by weight of the total weight of the hydrated borate oil dispersion. %, More preferably about 30 to 40% by weight. (All percentages are by weight unless otherwise specified.)

  The additive composition and lubricant composition of the present invention can further use surfactants, detergents, other dispersants, and other conditions as described below, which are known to those skilled in the art. . The additive composition optionally contains an alkyl aromatic or polyisobutenyl sulfonate.

  Oil dispersions of hydrated alkali metal borates used in the present invention generally include a dispersant, an oil of lubricating viscosity and optionally a detergent, which are described in further detail below.

[Dispersant]
The dispersant used in the oil dispersion of the hydrated alkali metal borate used in the present invention is an ashless dispersant such as alkenyl succinimide, alkenyl succinic anhydride and alkenyl succinate, or such a dispersant. It may be a mixture of

  Ashless dispersants are roughly classified into several groups. One such group is copolymers comprising carboxylic acid esters with one or more additional polar functions including amines, amides, imines, imides, hydroxyl carboxyls and the like. These products can be produced by copolymerizing a long-chain alkyl acrylate or methacrylate with a monomer having the above function. Such groups include alkyl methacrylate-vinyl pyrrolidinone copolymers, alkyl methacrylate-dialkylaminoethyl methacrylate copolymers, and the like. In addition, high molecular weight amides and polyamides or esters and polyesters such as tetraethylenepentamine, polyvinyl polystearate, and other polystearamides can be used. A preferred dispersant is an N-substituted long chain alkenyl succinimide.

  Alkenyl succinimides are usually derived from the reaction of alkenyl succinic acid or anhydride and alkylene polyamines. These compounds are generally considered to have the following formula:

In the formula, R ^1, substantially hydrocarbon radical having a molecular weight of about 400 to 3000, namely R ¹ is a hydrocarbon group, preferably an alkenyl group containing from about 200 30 to about carbon atoms; Alk is An alkylene group having 2 to 10 carbon atoms, preferably 2 to 6; R ² , R ³ and R ⁴ are selected from C ₁ -C ₄ alkyl or alkoxy or hydrogen, preferably hydrogen; and x is an integer of 0 to 10, preferably 0 to 3. The actual reaction product of alkylene succinic acid or its anhydride and alkylene polyamine consists of a mixture of compounds including succinamic acid and succinimide. However, it is customary to represent this reaction product as a succinimide of the above formula because it is the main component of the mixture. See, for example, U.S. Pat. Nos. 3,202,678, 3,024,237, and 3,172,892.

These N-substituted alkenyl succinimides can be produced by reacting maleic anhydride with an olefinic hydrocarbon and then reacting the resulting alkenyl succinic anhydride with an alkylene polyamine. The R ₁ group of the above formula, ie, the alkenyl group, is preferably derived from a polymer synthesized from an olefin monomer containing 2 to 5 carbon atoms. Thus, alkenyl groups are obtained by polymerizing olefins containing 2 to 5 carbon atoms to produce hydrocarbons having a molecular weight in the range of about 400 to 3000. Examples of such olefin monomers include ethylene, propylene, 1-butene, 2-butene, isobutene, and mixtures thereof.

  Preferred polyalkyleneamines used to make succinimides are those having the formula:

In the formula, z is an integer of 0 to 10, and Alk, R ² , R ³ and R ⁴ are as defined above.

  The alkylene amines are mainly methylene amine, ethylene amine, butylene amine, propylene amine, pentylene amine, hexylene amine, heptylene amine, octylene amine, other polymethylene amines, and cyclic and higher order of such amines. Analogs such as piperazine and aminoalkyl-substituted piperazine may be mentioned. Examples of those include ethylenediamine, triethylenetetraamine, propylenediamine, decamethyldiamine, octamethylenediamine, diheptamethylenetriamine, tripropylenetetraamine, tetraethylenepentamine, trimethylenediamine, pentaethylenehexamine, ditrimethyl. Methylenetriamine, 2-heptyl-3- (2-aminopropyl) -imidazoline, 4-methylimidazoline, N, N-dimethyl-1,3-propanediamine, 1,3-bis (2-aminoethyl) imidazoline, 1 There are-(2-aminopropyl) -piperazine, 1,4-bis (2-aminoethyl) piperazine, and 2-methyl-1- (2-aminobutyl) piperazine. Such higher order analogs are obtained by condensing two or more of the above alkylene amines and are useful as well.

  Ethyleneamine is particularly useful. They are described in Encyclopedia of Chemical Technology, Kirk-Othmer, Volume 5, p. 898-905, “ethyleneamine” (Interscience Publishing, New York, 1950).

“Ethyleneamine” is used in a generic sense and refers to a class of polyamines, most of which apply to the following structures. However, a is an integer of 1-10.

H ₂ N (CH ₂ CH ₂ NH) _a H

  Accordingly, examples thereof include ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, and pentaethylenehexamine.

  "Alkenyl succinimide" includes, for example, a post-treatment method containing ethylene carbonate disclosed in US Pat. Nos. 4,612,132 (Warenberg, Outer) and 4,746,446 (Worenberg, Outer), and other post-treatment methods. Post-treated succinimides are also included, the disclosures of each of which are incorporated herein by reference.

  The dispersant component, such as a polyalkylene succinimide component, preferably comprises 2-40% by weight of the hydrated alkali metal borate oil dispersion, more preferably 5-20% by weight and even more preferably. Accounts for 5 to 15% by weight.

  Polyalkylene succinic anhydrides, or non-nitrogen containing derivatives of polyalkylene succinic anhydrides (eg, succinic acid, Group I and / or II mono- or bimetallic salts of succinic acid, and polyalkylene succinic anhydride, Succinates and the like produced by the reaction of acid chlorides or other derivatives with alcohols are also suitable dispersants for use in the compositions of the present invention.

  As the polyalkylene succinic anhydride, polyisobutenyl succinic anhydride is preferable. In a preferred embodiment, the polyalkylene succinic anhydride is a polyisobutenyl succinic anhydride having a number average molecular weight of at least 500, more preferably at least 900 to about 3000, and more preferably at least about 900 to about 2300. .

  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 about 500 to less than 1000 and the high molecular weight component has a number average molecular weight of 1000 to about 3000. More preferably, both the low molecular weight component and the high molecular weight component are polyisobutenyl succinic anhydrides. Alternatively, polyalkylene succinic anhydride components of various molecular weights can be combined as a dispersant and as a mixture with other dispersants as defined above.

  As described above, polyalkylene succinic anhydride is a reaction product of polyalkylene (preferably polyisobutene) and maleic anhydride. Conventional polyisobutene or high methylvinylidene polyisobutene can be used for producing such polyalkylene succinic anhydride. For this production, a thermal method, a chlorination method, a free radical method, an acid catalyst method, or any other method can be used. Examples of suitable polyalkylene succinic anhydrides include thermal PIBSA (polyisobutenyl succinic anhydride) described in US Pat. No. 3,361,673, chlorinated PIBSA described in US Pat. No. 3,172,892, and US Pat. A mixture of thermal and chlorinated PIBSA as described in U.S. Pat. No. 3,127,644; high succinic acid ratio PIBSA as described in U.S. Pat. No. 4,234,435; High succinic acid ratio poly PIBSA described in US Pat. No. 5,616,668, free radical PIBSA described in US Pat. Nos. 5,286,799, 5,319,030 and 562,004, and high methyl described in US Pat. Vinylidene polybutene Synthesized PIBSA, high succinic acid ratio PIBSA synthesized from high methylvinylidene polybutene as described in EP 355895, terpolymer PIBSA as described in US Pat. No. 5,792,729, US Pat. No. 5,777,025 and European patent There are sulfonated PIBSA as described in published application EP 542380 and purified PIBSA as described in US Pat. No. 5,523,417 and published European patent application EP 602 863. The disclosure content of each of these documents is also described in this specification as reference content.

  The polyalkylene succinic anhydride or other dispersant component preferably comprises 2-40% by weight of the hydrated alkali metal borate oil dispersion, more preferably 5-20% by weight, and even more Preferably it occupies 5 to 15% by weight.

  Generally, in oil dispersions of hydrated alkali metal borates, the hydrated alkali metal borates are in a ratio of at least 2: 1 to polyalkylene succinic anhydride or other dispersant, while preferably It is in the range of 2: 1 to 10: 1. In a more preferred embodiment, the ratio is at least 5: 1. In another preferred embodiment, a mixture as defined above of polyalkylene succinic anhydride is used.

[Cleaning agent]
The oil dispersion of the hydrated alkali metal borate used in the additive composition of the present invention may optionally contain a detergent. There are a number of substances that are suitable for the purposes of the present invention. These materials can include phenates (high or low overbased), high overbased phenate stearates, phenolates, salicylates, phosphonates, thiophosphonates and sulfonates, and mixtures thereof. Preferably, sulfonates such as high overbased sulfonates, low overbased sulfonates or phenoxy sulfonates are used. Furthermore, sulfonic acid itself can also be used.

  The sulfonate detergent is preferably an alkali or alkaline earth metal salt of a hydrocarbon sulfonic acid having 15 to 200 carbon atoms. “Sulfonate” preferably includes salts of sulfonic acids derived from petroleum products. Such acids are also well known in the art. It can be obtained by treating petroleum products with sulfuric acid or sulfur trioxide. The acid thus obtained is known as petroleum sulfonic acid and its salt is known as petroleum sulfonate. The majority of petroleum products that are sulfonated contain oil-soluble hydrocarbon groups. The meaning of “sulfonate” also includes sulfonic acid salts of synthetic alkylaryl compounds. These acids are also produced by treating alkylaryl compounds with sulfuric acid or sulfur trioxide. At least one alkyl substituent on the aryl ring is an oil solubilizing group as described above. The acids thus obtained are known as alkylaryl sulfonic acids and their salts are known as alkylaryl sulfonates. Sulfonates in which the alkyl is linear are known linear alkyl aryl sulphonates.

  The acid obtained by sulfonation is converted to a metal salt by neutralizing with a basic and reactive alkali or alkaline earth metal compound to form a Group I or Group II metal sulfonate. In general, the acid is neutralized with an alkali metal base. Alkaline earth metal salts are obtained from alkali metal salts by metathesis. Alternatively, the sulfonic acid can be directly neutralized with an alkaline earth metal base. The sulfonate may be overbased, but overbasing is not essential for the purposes of the present invention. Overbased materials and methods of making such materials are well known to those skilled in the art. See, for example, U.S. Pat. No. 3,496,105 (Rusu), issued February 17, 1970, especially columns 3, 4.

  The sulfonate is 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 latter two are preferred.

  However, especially preferred are petroleum sulfonic acid salts because of their wide availability, and particularly obtained by extracting various hydrocarbon fractions such as lubricating oil fractions and hydrocarbon oils with a selected solvent. Is a salt of petroleum sulfonic acid obtained by sulfonation of an aromatic-rich extract, which is optionally reacted with an olefin or alkyl chloride using an alkylation catalyst prior to sulfonation. May be used. Moreover, it is a salt of organic polysulfonic acid such as benzenedisulfonic acid, which may or may not be alkylated.

  Preferred salts for use in the present invention are salts of alkylated aromatic sulfonic acids in which the alkyl group (s) contain at least about 8 carbon atoms, such as about 8-22 carbon atoms. Another preferred group of sulfonate starting materials are aliphatic substituted cyclic sulfonic acids in which the aliphatic substituent (s) contain at least 12 carbon atoms in total, for example, the aliphatic group (s) in total contain carbon atoms. Are alkyl aryl sulfonic acids, alkyl alicyclic sulfonic acids, alkyl heterocyclic sulfonic acids, and aliphatic sulfonic acids. Specific examples of these oil-soluble sulfonic acids include petroleum sulfonic acids, mono and poly wax substituted naphthalene sulfonic acids, substituted sulfonic acids such as cetyl benzene sulfonic acid, and cetyl phenyl sulfonic acid, aliphatic sulfonic acids such as paraffin wax sulfone. Examples include acid, hydroxy-substituted paraffin wax sulfonic acid, alicyclic sulfonic acid, petroleum naphthalene sulfonic acid, cetylcyclopentyl sulfonic acid, and mono- and poly-wax substituted cyclohexyl sulfonic acid. “Petroleum sulfonic acid” is meant to include all sulfonic acids derived directly from petroleum products.

  Representative Group II metal sulfonates suitable for use in the present invention include the following metal sulfonates: calcium white oil benzene sulfonate, barium white oil benzene sulfonate, magnesium white oil benzene sulfonate, calcium dipolypropylene. Penbenzene sulfonate, barium dipolypropene benzene sulfonate, magnesium dipolypropene benzene sulfonate, calcium mahogany petroleum sulfonate, barium mahogany petroleum sulfonate, magnesium mahogany petroleum sulfonate, calcium triacontyl sulfonate, magnesium triacontyl sulfonate, calcium lauryl sulfonate, barium Lauryl sulfonate, magnesium lauryl sulfonate, etc. The concentration of metal sulfonate that can be used can vary widely depending on the concentration of the alkali metal borate particles. However, the concentration of detergent, if present, is generally in the range of about 0.2 to about 10% by weight, preferably about 3 to about 10%, based on the total weight of the hydrated borate oil dispersion. It is in the range of 7% by weight. In addition, the composition of the present invention may include a mixture of both a metal sulfonate and an ashless dispersant, as described above, the ratio achieving proper stability of the hydrated alkali metal borate oil dispersion. Is a factor.

[Oil of lubricating viscosity]
The lubricating oil to which the hydrated alkali metal borate and dispersant are added to form a hydrated alkali metal borate oil dispersion may be any hydrocarbon-based lubricant or synthesized. It may be a base oil raw material. Also, as described above, these lubricating oils can be added in additional amounts to the hydrated alkali metal borate oil dispersion and additive composition comprising it to produce a finished oil composition. . The hydrocarbon-based lubricating oil may be derived from synthetic or natural raw materials, and may be paraffinic, naphthenic or aromatic groups, or mixtures thereof. The diluent oil may be natural or synthetic and may be of various viscosity grades.

  In the hydrated alkali metal borate oil dispersion, the lubricating oil generally comprises from about 30 to 70 weight percent, more preferably from about 45 to 55 weight percent of the total weight of the hydrated alkali metal borate oil dispersion. %.

  Generally, the hydrated alkali metal borate oil dispersion is present in the additive composition of the present invention in the range of about 10 to 90% by weight, based on the total weight of the additive composition.

[Oil dispersion of hexagonal boron nitride]
The additive composition of the present invention further contains an oil dispersion of hexagonal boron nitride.

  Hexagonal boron nitride or h-BN is a hexagonal graphite-like type boron nitride, and has a planar 6-membered ring consisting of boron atoms and nitrogen atoms alternately in a laminated structure. On alternating surfaces, boron atoms come directly on nitrogen atoms. Hexagonal boron nitride can be produced by heating boron oxide, boric acid or borate together with ammonium chloride, alkali cyanide or calcium cyanamide at atmospheric pressure. Hexagonal boron nitride can also be produced by reaction of boron trichloride or boron trifluoride with ammonia. For the description of hexagonal boron nitride, see, for example, Kirk Osmer, Dictionary of Chemical Technology, 4th Edition, Volume 4, p. 427-429, John Willie and Sons, New York, 1992.

  In general, the average particle size of hexagonal boron nitride is 1 micron or less. Preferably, the hexagonal boron nitride has a particle size distribution such that 90% or more of the particles are about 0.5 microns (500 nanometers, nm) or less, with a preferred average particle size of about 0.00. 3 microns (300 nm) or less.

  Hexagonal boron nitride oil dispersions generally contain from about 1 to about 50 weight percent hexagonal boron nitride, preferably from about 1 to about 20 weight percent, and more preferably, based on the total weight of the oil dispersion. Contains from about 5 to about 15 weight percent.

  The oil dispersion of hexagonal boron nitride preferably contains a surfactant as a stabilizer for the oil dispersion. Typical surfactants used as stabilizers include ethylene-propylene copolymers or terpolymers of ethylene, propylene and non-conjugated dienes commonly known as ethylene-propylene-diene terpolymers. And an ethylene-propylene copolymer grafted with a nitrogen-containing vinyl functional group selected from the group consisting of N-vinylpyrrolidone and N-vinylpyridine. The average molecular weight of the ethylene-propylene copolymer is generally in the range of about 22,000 to 200,000. A preferred surfactant is an ethylene-propylene copolymer in which the ratio of ethylene monomer to propylene monomer is substantially the same and the average molecular weight is 22,000 to about 40,000. If a surfactant is present, its concentration in the hexagonal boron nitride oil dispersion is generally in the range of about 0.1 to about 25 weight percent based on the total weight of the hexagonal boron nitride oil dispersion. Preferably in the range of from about 2 to about 7 weight percent, and more preferably from about 3.0 to about 5.0 weight percent.

  The lubricating oil used to produce the hexagonal boron nitride oil dispersion is the same group of natural or synthetic lubricating oils used above to produce the hydrated alkali metal borate oil dispersion. Synthetic liquid lubricants such as vegetable oils such as rapeseed oil, liquid hydrocarbons such as aliphatic and aromatic naphtha and mixtures thereof, polyalphaolefins, polyglycols, liquid diesters and mixtures of these liquids Other carrier liquids have been found to be satisfactory. Also, the oil used to produce the hexagonal boron nitride oil dispersion is the same or different from the lubricating oil used to produce the hydrated alkali metal borate oil dispersion. It may be. Representative oils for producing hexagonal boron nitride oil dispersions include Class I or Group II base oils, such as 150 solvent neutral petroleum.

[Compound]
The additive composition of the present invention comprising an alkali metal borate and hexagonal boron nitride oil dispersion (as described above) is further blended with additional additives to provide the additive composition of the present invention. Can be produced. These additive packages generally consist of about 10 to 80% by weight of the additive composition of the present invention and about 90 to 20% by weight of one or more conventional additives, and the additive is an ashless dispersant. (0-10%), detergent (0-5%), sulfurized hydrocarbon (0-40%), dialkyl hydrogen phosphate (0-15%), zinc dithiophosphate (0-20%), phosphoric acid and / Or alkyl ammonium thio-dithiophosphate (0 to 20%), phosphite (0 to 10%), polyalcohol fatty acid ester (0 to 10%), 2,5-dimercaptothiadiazole (0 to 5%) ), Benzotriazole (0-5%), dispersed molybdenum disulfide (0-5%), antifoaming agent (0-2%), imidazoline (0-10%), and the like. However, each weight percent is based on the total weight of the composition.

  The fully formulated finished oil (formulated oil) composition of the present invention can be formulated from these additive packages by further blending with an oil of lubricating viscosity. Preferably, the additive package is added to the oil of lubricating viscosity in an amount of about 1 to 20% by weight, preferably about 2 to 15% by weight to form a finished oil composition. However, the weight percent of the additive package is based on the total weight of the composition.

  Various other additives may be present in the lubricating oil of the present invention. Such additives include antioxidants, rust inhibitors, corrosion inhibitors, extreme pressure agents, antifoaming agents, other antiwear agents, and other various additives known in the art. it can.

  The invention is further illustrated by the following examples, which represent particularly advantageous embodiments. The examples are provided to illustrate the invention and are not intended to limit the invention.

[Example 1]
For the additive composition of the present invention, SAE No. According to a test using two benches, its sticking prevention property was evaluated in lubricating oil. The test evaluates the transmission fluid during synchronization. The friction pair used for this bench consisted of a brass synchronizer ring and a steel gear cone.

  During each cycle of the test, the cone is rotated at a constant speed and then the ring is moved along the cone axis to brake the cone until it is disturbed. At the end of each cycle, the ring comes out.

  If sticking occurs, measure the sticking torque when the cone rotation is restarted. During the test, the lubricating oil and metal parts are heated to a temperature between about 60 ° C and 90 ° C. The contact pressure is about 20 MPa, and the initial sliding speed is 1.6 m / sec.

The anti-sticking factor for this test was calculated as follows:

Anti-sticking factor = 1-[(number of sticking cycles) / (total number of test cycles)]

  Thus, an anti-stick factor of 0 indicates that there was cone and ring sticking at any cycle of the test. Conversely, an adhesion prevention factor of 1 indicates that no adhesion was observed over the entire test period. Therefore, the higher the anti-adhesion coefficient is up to 1, the better the anti-adhesion performance of the lubricating oil.

  The test lubricant composition was formulated as follows:

Lubricant composition 1
A lubricant composition was prepared containing the following ingredients:
(A) 7 wt% hydrated potassium triborate oil dispersion, wherein the oil dispersion contained about 30 wt% hydrated potassium triborate dispersed in 150N neutral oil;
(B) an oil dispersion of 10 wt% hexagonal boron nitride, wherein the oil dispersion contained about 10 wt% hexagonal boron nitride solid dispersed in 150N neutral oil with stabilizer, and (C) 50/50 mixture of 83 wt% neutral oil (150N and 600N) and synthetic polyalphaolefin oil.

Lubricant composition 2
Lubricant composition 2 was prepared containing the following ingredients:
(A) 7 wt% hydrated potassium triborate oil dispersion, wherein the oil dispersion contained about 30 wt% hydrated potassium triborate dispersed in 150N neutral oil;
(B) 5 wt% hexagonal boron nitride oil dispersion, wherein the oil dispersion contained about 10 wt% hexagonal boron nitride solids dispersed in a 150N neutral oil containing stabilizer; And (c) a 50/50 mixture of 88 wt% neutral oil (150N and 600N) and a synthetic polyalphaolefin oil.

Lubricant composition 3
Lubricant composition 3 was prepared containing the following ingredients:
(A) 7 wt% hydrated potassium triborate oil dispersion, wherein the oil dispersion contained about 30 wt% hydrated potassium triborate dispersed in 150N neutral oil;
(B) 2.5 wt% hexagonal boron nitride oil dispersion, wherein the oil dispersion contains about 10 wt% hexagonal boron nitride solids dispersed in a 150N neutral oil containing stabilizer. And (c) a 50/50 mixture of 90.5 wt% neutral oil (150N and 600N) and a synthetic polyalphaolefin oil.

Lubricant composition A (comparison)
A lubricating oil composition was prepared containing the following ingredients:
(A) an oil dispersion of 7 wt% hydrated potassium triborate, wherein the oil dispersion contained about 30 wt% hydrated potassium triborate dispersed in 150N neutral oil; and (b) A 50/50 mixture of 93 wt% neutral oil (150N and 600N) and a synthetic polyalphaolefin oil.

Lubricant composition B (comparison)
A lubricating oil composition was prepared containing the following ingredients:
(A) 10 wt% hexagonal boron nitride oil dispersion, wherein the oil dispersion contains about 10 wt% hexagonal boron nitride solids dispersed in a 150N neutral oil containing stabilizer; And (b) a 50/50 mixture of 90% by weight neutral oil (150N and 600N) and a synthetic polyalphaolefin oil.

  About said lubricant composition, the anti-adhesion performance was evaluated in the synchronous test mentioned above. Base oils without additives, including a 50/50 mixture of 150N and 600N neutral oils, were also tested. Table 1 shows the results of these evaluations.

Table 1
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Sample Cone and ring Total number of cycles Adhesion prevention factor
Number of cycles that were sticky ────────────────────────────────────
Base oil 5000 5000 0
Comparative composition A 8100 8100 0
Comparative composition B 6600 6600 0
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Composition 1 1200 7500 0.84
Composition 2 1600 8710 0.82
Composition 3 300 10560 0.97
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  The above data reveals that the additive composition of the present invention provides significant anti-tack performance and represents a significant improvement over the comparative composition.

  From the foregoing description, one skilled in the art will be able to conceive of various modifications or replacements of the invention described above. All such modifications that fall within the scope of the appended claims are intended to be embraced by the present invention.

Claims (17)

(A) an oil dispersion of hydrated alkali metal borate, and (b) an oil dispersion of hexagonal boron nitride,
Hints, the weight ratio of the hydrated alkali metal borate and hexagonal boron nitride 9 5: 5乃Itaru 5: transmission oil additive composition in the range of 95.   The additive composition according to claim 1, wherein the alkali metal of the hydrated alkali metal borate is sodium or potassium.   The additive composition according to claim 2, wherein the alkali metal is potassium.   The additive composition according to claim 3, wherein the hydrated alkali metal borate is hydrated potassium triborate.   The additive composition according to claim 1, wherein the oil dispersion of hydrated alkali metal borate comprises a hydrated alkali metal borate, a dispersant, and an oil of lubricating viscosity. Oil dispersions of hydrated alkali metal borate is additive according to claim 5 containing based-out 1 0乃Optimum 7 5 wt% of the hydrated alkali metal borate to the total weight of the oil dispersion Composition. Oil dispersions of hydrated alkali metal borate is The additive composition of claim 5 containing based-out 2乃Optimum 4 0% by weight of a dispersing agent to the total weight of the oil dispersion.   The additive composition according to claim 5, wherein the oil dispersion of the hydrated alkali metal borate further contains a detergent. Oil dispersions of hydrated alkali metal borate is-out based on the total weight of the oil dispersion 0. The additive composition according to claim 8 containing 2乃optimum 1 0 wt% of detergent. Oil dispersions of hydrated alkali metal borate is added according to claim 1 which is present in the additive composition in the total weight in the range 1 0乃Itaru 9 0 wt%-out based additive compositions Agent composition. Hexagonal boron nitride, 90% or more particles 0. The additive composition of claim 1 having a particle size distribution that is 5 microns or less. Oil dispersion of hexagonal boron nitride, an oil of lubricating viscosity, and added according to the total weight of the oil dispersion in claim 1 containing based-out 1乃optimum 5 0 wt% of hexagonal boron nitride Agent composition.   The additive composition according to claim 12, wherein the hexagonal boron nitride oil dispersion further contains a surfactant as a stabilizer. Oil dispersion of hexagonal boron nitride, the additive composition of claim 1 present in the additive composition in total weight of based-out 1 0乃optimum 9 0 weight percent range of the additive composition object. A lubricating oil composition comprising a transmission oil of a major amount of lubricating viscosity and an additive composition comprising an amount of the following components effective to reduce synchronizer adhesion:
(A) an oil dispersion of hydrated alkali metal borate, and (b) an oil dispersion of hexagonal boron nitride,
However, the weight ratio of the hydrated alkali metal borate and hexagonal boron nitride 9 5: 5乃Itaru 5: in the range of 95. Lubricating oil composition The lubricating oil composition of claim 15 containing the entire weight based-out 1乃Optimum 2 0 wt% of the additive composition of the lubricating oil composition.   The lubricating oil composition according to claim 15, wherein the transmission oil is a manual transmission gear oil.