KR20150124992A - Limited slip friction modifiers for differentials - Google Patents

Abstract

It is an object of the present invention to provide a lubricant composition for limiting slip differentials containing a major amount of oil and oil soluble compounds having a major amount of lubricating viscosity, as well as a method of using them in a differential. The compound can be represented by the formula R'NH (CH ₂ ) ₃ NHCOR ", where R 'can be C _8-28 amine and -COR" can be derived from C _8-28 acid.

Description

LIMITED SLIP FRICTION MODIFIERS FOR DIFFERENTIALS FOR DIFFERENTIAL DEVICES

The present invention relates to a lubricating composition comprising (a) an oil of lubricating viscosity and (b) an oil soluble compound. The present invention also provides the use of a lubricating composition for use in lubricating limited slip differentials.

The differential of a vehicle is generally a bevel gear or a spur gear satellite system that uniformly distributes drive torque to two driving wheels regardless of the rotational speed. ). This allows the wheel to be driven without slip between the wheel and the road surface despite different rotational speeds during cornering. When one wheel is on a low traction surface, the amount of torque that can be transmitted is limited to the amount that can be applied before the wheel slips.

The limiting slip differential generally uses a wet multiplate clutch, i.e., a clutch plate in contact with the lubricant, to provide more torque to the non-slipping wheel during a slipping situation. During normal rotation, one wheel must loosen or release the clutch plate to rotate faster than the other. There may be NVH (noise, vibration, harshness) associated with this event.

To allow the slip to be controlled, a lubricant containing a compound capable of improving the friction performance, a dispersant and / or a sulfur- and / or phosphorus-containing extreme pressure agent may be used. Examples of this type of lubricant are described in U.S. Patent Nos. 4,308,154; 4,180,466; 3,825,495; And European Patent Application 0 399 764 A1.

A particular class of compounds that can improve friction performance is taught, for example, in US 5,021,176 (Bullen et al., Issued June 1991). Bullen teaches, among other things, the diamine with the structure shown below, as a friction reducing additive, especially in a wet braking system.

Likewise, WO 2010/096325 (inventor Saccomando et al., Published Aug. 26, 2010) and US 4,446,053 (Skrobul et al., Granted April 5, 1984) teach amine-type compounds for friction control.

Saccomando is a composition for use as a friction modifier for automatic transmissions that teaches a composition containing long chain hydrocarbyl amines having one or two additional groups on one or two different amine nitrogen atoms. One of the species presented in this publication is a compound of the formula XIIa, which is represented by the formula R ¹ N ((CH ₂ ) ₂ CONH (CH ₂ ) ₃ NHR ⁴ ) ₂ .

Skrobul teaches the friction reducing additives of engine oils characterized by the formula RNHCH ₂ CH ₂ CO ₂ ^- Na ⁺ and RNHCH ₂ CH ₂ CONH ₂ .

Both the succinimene and the scorch teach the use of amine compounds used for the friction performance of limiting slip differentials, which do not include the compounds as taught herein.

US 2012/0015855 (Saccomando et al., Published Jan. 19, 2012) and US 2012/0122744 (Saccomando et al., Published Dec. 17, 2012) disclose various classes of amine friction modulating compounds that do not include the compounds taught herein do.

US 5,372,735 (Ohtani et al., Issued Dec. 13, 1994) teaches an automatic transmission fluid having a friction modifier content consisting essentially of hydrocarbyl substituted diethanolamine and hydrocarbyl N-substituted trimethylenediamine. The compounds of the present invention do not require the synergistic amount of other compounds such as diethanolamine and the compounds taught further herein are different from the diethanolamine and N-substituted trimethylenediamine taught in the Otani literature .

GB 1209548 teaches a vehicle fuel composition containing an amide of the formula:

Wherein R is hydrocarbyl having 17 carbon atoms derived from oleic acid and R 'and R "are alternating hydrocarbyl radicals having from 14 to 18 carbon atoms. Do not teach the use of compounds of the above formula in lubricants for limiting slip differentials.

Another patent JP 63060956 teaches compounds useful as synthetic resin lubricants, including, inter alia, the bisamidation of fatty acids and diamines. The JP'956 patent does not teach the use of amine compounds used for friction performance in limited slip differentials.

US 4,581,039 (Horodysky, Aug. 8, 1986) teaches antifriction carboxylates represented by the following formula for engine oils and fuel compositions:

According to a preferred embodiment, the formula R ₃ and R ₄ are H. The carboxylate formulas do not include the compounds disclosed herein, and in particular teach the opposite of amide production (column 2, lines 13-19 - "prevention of amide formation"). In addition, this patent does not teach the use of such compounds for use in limiting slip differentials.

WO 2010/096318 (published Aug. 26, 2010) teaches antifriction compounds for automatic transmissions represented by the following formulas. This publication does not teach the use of compounds used in limiting slip differentials:

It is desirable that the lubricant for the limiting slip differential be capable of providing a high coefficient of friction and a tendency towards low noise, vibration and haze.

It is an object of the present invention to provide a method and apparatus for noise, vibration and harshness (NVH) which are identified as chatter (i.e., abnormal noise, sometimes referred to as "growl" and "groan" And to provide a lubricating composition and method as disclosed herein which can provide a low tendency and a high coefficient of friction for the lubricating composition. The inventors have also unexpectedly discovered that the lubricating compositions and methods disclosed herein may also be suitable for limiting slip systems having one or more unique plate materials. For example, the plate material can be a system that utilizes a composite plate type such as steel, paper, ceramic, carbon fiber and ceramic-on-ceramic, carbon fiber in paper or steel on paper.

According to one aspect, the present invention provides (a) a major amount of a lubricating viscosity oil, and (b) (1), the N- substituent derived from a C _{8 -28} by N- substituted 1,3-diaminopropane And (2) at least one oil-soluble compound containing a condensation product of C _{8 -28} acid.

The C _{8 -28} amine of _formula (1) is a fatty amine and the C _{8 -28} acid of (b) is at least one of fatty acid or fatty acid chloride. However, the amines and acids are not particularly limited, and may be any amine and acid suitable for preparing the oil soluble compounds as described for the intended purpose in the limiting slip system.

According to one aspect of the lubricant, the condensation product is the formula R'NH (CH _{2) 3} may contain a compound represented by NHCOR ". Preferably, R 'is derived from a C _{8 -28} of the amine (1) Substituent, and -COR "is derived from C _{8 -28} acid of (2).

According to a particularly preferred embodiment, R 'may be derived from a C ₁₈ fatty amine, such as oleylamine, and -COR "may be derived from a C ₁₈ fatty acid, such as oleic acid.

According to a further aspect, there is provided a lubricating composition comprising a lubricating composition comprising an oil soluble compound as described herein, or an oil soluble compound as described herein, in a limiting slip differential, and operating the limiting slip differential, A method is provided for providing a limiting slip capability to the device.

According to another aspect, there is provided the use of a lubricant as described above to provide limited slip differential performance to a limiting slip differential.

Various preferred features and aspects will now be described as non-limiting examples.

As used herein, the expression "oil solubility" or "hydrocarbon solubility" refers to the ability to dissolve or disperse in oil or hydrocarbons, optionally in mineral oil, on a macroscopic or gross scale, it means. In order to produce a useful lubricant formulation, the material should preferably not settle or precipitate over a period of days or weeks. These materials may exhibit solubility at the molecular scale, or they may be present in the form of agglomerates of various sizes or scales, but must be soluble or dispersed on the visual scale.

As used herein, the term "hydrocarbyl group" or "hydrocarbyl substituent" is used in its conventional sense as known to those skilled in the art. In particular, a carbon atom is attached directly to the remainder of the molecule and has predominantly hydrocarbon character. Examples of hydrocarbyl groups include the following:

(i) hydrocarbon substituents, i.e., aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents and aromatic-, aliphatic- and alicyclic-substituted aromatic substituents, A cyclic substituent where the ring completes through a moiety (e. G., When two substituents together form a ring);

(ii) a substituted hydrocarbon substituent, i.e., a substituent containing a non-hydrocarbon group (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, Nitro, nitroso and sulfoxy);

(iii) Heterocyclic substituents, i.e., substituents containing a carbon atom other than carbon in the ring or chain consisting of carbon atoms in the context of the present invention, but which possess key hydrocarbon properties and which bear substituents such as pyridyl, furyl, thienyl and imidazolyl ; And

(iv) Heteroatom including sulfur, oxygen and nitrogen. In general, non-hydrocarbon substituents will be present in the hydrocarbyl group no more than 2, preferably no more than 1 per 10 carbon atoms; Typically, no hydrocarbyl substituent will be present in the hydrocarbyl group.

One aspect of the present invention is a lubricant for a limited slip differential comprising an oil soluble compound. According to one embodiment, the oil soluble compound may be (a) a condensation product of an N-substituted 1,3-diaminopropane and (b) an acid. The N-substituent on 1,3-diaminopropane may be derived from an amine.

N-Substituted amines and acids are not particularly limited and may be any amine and acid suitable for preparing oil soluble compounds as described for the intended purpose in a limiting slip system.

According to a preferred embodiment, the N-substituent of the N-substituted 1,3-diaminopropane of (a) may be derived from a hydrocarbyl substituted amine, i. The alkylamine may contain one alkyl substituent or a mixture of alkyl substituents. It is preferred that the amine is C _{8 -28} amine, or in some cases C _{9 -26} amine, more preferably C _{10 -24} amine, or C _{11 -22} amine. The amine may also be about C ₁₆ or C ₁₈ to C ₂₀ .

Particularly preferred amines include fatty amines and / or fatty amine mixtures such as soya amines, oleylamines, tallowamines, cocoamines and the like. According to a preferred embodiment, the amine is oleylamine. According to another preferred embodiment, the amine is talloamine.

According to a preferred embodiment, the acid C _{8 -28} when acid, or in some cases _-26 C ₉ to acid, more preferably a C ₁₀ or C _{11 -22 -24} acid acid. Also, the acid may be about C ₁₆ or C ₁₈ to C ₂₀ . In some embodiments, the acid can be, for example, a fatty acid, and in other embodiments, the acid can be a fatty acid chloride.

Particularly preferred acids include fatty acids such as myristic acid, palmitic acid, behenic acid, eruic acid, oleic acid, stearic acid, linoleic acid and lauric acid and the like. According to a preferred embodiment, the acid may be oleic acid. According to another preferred embodiment, the acid may be linoleic acid.

According to one embodiment of the oil soluble compound described above, the condensation product may contain a compound of the formula R'NH (CH ₂ ) ₃ NHCOR "R 'is an N-substituent derived from the amine of (a) COR "is preferably derived from the acid of (b).

R 'and -COR "may be derived from derivatives of the same or different precursors. For example, R' and -COR" may be derived from derivatives of oleyl precursors such as oleic acid, or R ' R " may be derived from a C ₁₈ fatty amine, such as an olefin amine, and may be derived from a derivative of a precursor, COR "may be derived from a _C18 fatty acid, such as oleic acid.

The oil soluble compound according to the above aspects can be used in a lubricating composition with an oil of lubricating viscosity to provide a friction performance to the limiting slip differential. The oil soluble compound may be present in an amount of from about 0.1 to about 8 wt%, or from 0.2 to about 7 wt%, on an oil-free basis, and in some embodiments from about 0.25 to about 5 or about 6 wt%, or in particular from about 0.25 to about 1 wt% , Or 2 or 3 or about 4 wt%.

Oil of lubricating viscosity

The lubricating composition comprises a major amount of oil of lubricating viscosity. Such oils include natural and synthetic oils, oils derived from hydrocracking, hydrogenation and hydrofinishing finishes, crude oils, refined oils, refined oils or mixtures thereof. A more detailed description of crude oils, refined oils and refereed oils is provided in International Publication WO 2008/147704, paragraphs [0054] to [0056].

Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized olefins and interpolymerized olefins (also known as polyalphaolefins); Polyphenyl; Alkylated diphenyl ethers; Alkyl- or dialkylbenzenes; And alkylated diphenyl sulfide; And derivatives, analogs and analogs thereof. Also included are alkylene oxide polymers and interpolymers and derivatives thereof, wherein the terminal hydroxy groups may have been modified by esterification or etherification. Also included are esters of various alcohols and dicarboxylic acids, or esters prepared from C ₅ to C ₁₂ monocarboxylic acids and polyols or polyol ethers. Other synthetic oils include silicon-based oils, liquid esters of phosphorus-containing acids, and polymeric tetrahydrofuran. Synthetic oils may be produced by the Fischer-Tropsch reaction and may generally comprise hydrogenated isomerized Fischer-Tropsch hydrocarbons and / or waxes, or hydrogenated isomerized slack waxes. According to one embodiment, the oil may be prepared by a Fischer-Tropsch gas-liquid synthesis procedure as well as other gas-liquid oils.

Oil of lubricating viscosity is also defined as specified in the April 2008 edition of the "Base Stock Categories" section 1.3 Sub-heading 1.3. "Appendix E - API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils" According to one embodiment, the oil of lubricating viscosity may be an API Group I, Group II, Group III or Group IV oil.

Polyalpha olefins are classified as Group IV oils. According to one embodiment, at least 50% by weight of the lubricating viscosity oil is a polyalphaolefin (PAO). Generally, polyalphaolefins are derived from monomers having from 4 to 30 carbon atoms, from 4 to 20, or from 6 to 16 carbon atoms. Examples of useful PAOs include those derived from 1-decene. Such PAO may have a viscosity of 1.5 to 150 mm2 / s (cSt) at 100 占 폚. PAOs are generally hydrogenated materials.

The amount of lubricating viscosity oil present is generally the remainder after subtracting the sum of the amounts of the compound of the present invention and other performance additives from 100 wt%.

The lubricating composition may be in the form of a concentrate and / or a finished lubricant. If the lubricating composition of the present invention (including the additives disclosed herein) is in the form of a concentrate that is combined with the additional oil to form a final lubricant wholly or partly, the ratio of oil and / or diluting oil to lubricant viscosity with such additive is 1:99 To 99: 1 (by weight), or 80:20 to 10:90 (by weight).

Other performance additives

The composition of the present invention optionally further comprises at least one other performance additive. Other performance additives include dispersants, metal deactivators, detergents, viscosity modifiers, extreme pressure agents (generally boron- and / or sulfur- and / or phosphorous-containing), antiwear agents, antioxidants (e.g., hindered phenols, Antioxidants or molybdenum compounds), corrosion inhibitors, foam inhibitors, anti-emulsifiers, pour point depressants, seal swell agents, friction modifiers and mixtures thereof.

The total amount of other performance additives (excluding viscosity modifiers) present on an oil-free basis is from 0.01 wt% to 25 wt%, or from 0.01 wt% to 20 wt%, or from 0.1 wt% to 15 wt%, or from 0.5 wt% To 10 wt%, or from 1 to 5 wt%. One or more other performance additives may be present, but other performance additives are generally present in different amounts.

According to one embodiment, the lubricating composition is free of a molybdenum-containing additive.

Detergent

One additional component of the disclosed lubricant may be an overbased metal-containing cleaner. A detergent is an overbased salt generally called an overbased salt or a superbased salt and is usually an overbased metal that has an excess of the amount that can exist for neutralization depending on the stoichiometry of metal and detergent anions. System. The amount of excess metal is generally expressed in terms of the metal ratio, i.e. the ratio of the total equivalents of the metals to the equivalents of the acidic organic compounds. An overbased base material is prepared by reacting an acidic material (e.g., carbon dioxide) with an acidic organic compound, an inert reaction medium (e.g., mineral oil), a stoichiometric excess of a metal base and a cocatalyst such as phenol or an alcohol. Acidic organic materials will generally have a sufficient number of carbon atoms to provide oil solubility.

An overbased detergent may be characterized by a total base (TBN), expressed as KOH mg / g of sample, which is the amount of strong acid required to neutralize the basicity of the material in its entirety. The TBN is to be recalculated on an oil-free basis, since the overbased detergent is usually provided in the form of a diluent oil for the purposes of this document. Various detergents may have a TBN of from 100 to 1000, 150 to 800, or 400 to 700.

Metal compounds generally useful in preparing basic metal salts are generally any Group 1 or Group 2 metal compounds (the Periodic Table of the Elements of the CAS version). Examples include alkali metals such as sodium, potassium, lithium, copper, magnesium, calcium, barium, zinc and cadmium. According to one embodiment, the metal is sodium, magnesium or calcium. The anion sites of the salt may be hydroxides, oxides, carbonates, borates or nitrates. Particularly advantageous detergents in the art will generally be calcium-based cleaners prepared using calcium oxide or calcium hydroxide. Particularly advantageous detergents are carbonated detergents, so these detergents will be substances treated with carbon dioxide. This treatment more effectively incorporates the basic metal into the composition. The preparation of high TBN detergents which accompany reactions with carbon dioxide is described, for example, in US 7,238,651 (Kocsis et al., 2007.7.3 (see, e.g., Examples 10-13 and claims). However, other detergents may also be present in some cases, which need not be carbonated or need to be more highly overbased (i.e., lower TBN). However, if a large number of detergents are present, the overbased calcium aryl sulfonate detergent may be present in a major amount, on an oil-free basis, of at least 50 wt%, or at least 60 wt% or 70 wt% Or 80% by weight or 90% by weight.

Lubricants useful in the art may contain an overbased sulfonate detergent. Suitable sulfonic acids include sulfonic acids and thiosulfonic acids such as mono- or polynuclear aromatic or cycloaliphatic compounds. Specific oil soluble sulfonates may be represented by R ² -T- (SO ₃ ^- ) _a or R ³ - (SO ₃ ^- ) _b , wherein a and b are each at least 1; T is a cyclic nucleus such as benzene or toluene; R ² is an aliphatic group such as alkyl, alkenyl, alkoxy or alkoxyalkyl; (R < ² >) - T generally contain at least 15 carbon atoms in total; R ³ is generally an aliphatic hydrocarbyl group containing at least 15 carbon atoms. Furthermore, T, R ² and R ³ may contain other inorganic or organic substituents; It may also be described as a hydrocarbyl group. According to one embodiment, the sulfonate detergent may be predominantly a linear alkylbenzene sulfonate cleaner, as described in paragraphs [0034] to [0037] of U.S. Patent Application 2005-065045. According to some embodiments, a linear alkyl (or hydrocarbyl) group can be attached to the benzene ring at any position along the linear chain of the alkyl group, but can often be attached at position 2, 3 or 4 of the linear chain , And in some cases, mainly at position 2. According to other aspects, the alkyl (or hydrocarbyl) group may be branched and may be prepared from branched olefins such as propylene or 1-butene or isobutene. Also, sulfonate detergents having a mixture of a linear alkyl group and a branched alkyl group may be used.

Another class of overbased materials that can be further present in certain aspects of the present invention (i.e., in addition to the aryl sulfonate detergent) is an overbased phenate detergent. Certain commercial grade calcium sulfonate detergents contain small amounts of calcium phenate detergent to aid processing or for other reasons and may contain, for example, a 4% phenate substrate content and a 96% sulfonate substrate content. Phenols useful in the preparation of phenate detergents may be represented by (R ¹ ) _a -Ar- (OH) _b wherein R ¹ is selected from the group consisting of 4 to 400 carbon atoms, 6 to 80, 6 to 30, 8 to 25 Or an aliphatic hydrocarbyl group of 8 to 15 carbons; Ar is an aromatic group such as benzene, toluene or naphthalene; a and b are each at least 1 and the sum of a and b is not more than the number of substitutable hydrogen atoms in the aromatic nucleus of Ar, for example from 1 to 4 or from 1 to 2. The carbon atom provided by the R < ^{1 >} group for each phenolic compound is on average at least 7 or 8 aliphatic carbon atoms, in some cases about 12 carbon atoms. Also, phenate detergents are sometimes provided as sulfur-bridged or methylene-bridged species. Sulfur-crosslinked species can be prepared by reacting hydrocarbyl phenol with sulfur. Methylene-bridged species can be prepared by reacting hydrocarbylphenol with formaldehyde (or reactive equivalents such as paraformaldehyde). Examples include sulfur-bridged dodecylphenol (an overbased Ca salt) and methylene-coupled heptylphenol.

According to another embodiment, the optional additional overbased material is an overbased saligenin detergent. The overbased saligenin detergent is an overbased magnesium salt, which is generally based on saligenin derivatives. Typical examples of such saligenin derivatives may be represented by the formula:

Wherein X is -CHO or -CH ₂ OH, Y is -CH ₂ - or -CH ₂ OCH ₂ -, the -CHO group generally occupies at least 10 mol% of the X and Y groups; M is a valence of hydrogen, ammonium or metal ion (i.e., if M is multivalent, one valence must be met by the illustrated structure and the other valence must be met by another species, such as an anion, Must be met by example); R ₁ is a hydrocarbyl group of 1 to 60 carbon atoms, m is 0 to generally 10, each p is independently 0, 1, 2 or 3, provided that at least one aromatic ring contains an R ¹ substituent And the total number of carbon atoms present in all R < ^{1 >} groups must be at least 7. When m is 1 or more, one of the X groups may be hydrogen. According to one embodiment, M is the valence (or equivalence) of a Mg ion, or a mixture of Mg and hydrogen. Saligenin detergents are described in more detail in U.S. Patent 6,310,009, which specifically refers to the synthesis method (column 8 and example 1) and the preferred amount of various species of X and Y (column 6).

Other optional detergents include salicylate detergents. A salicylate detergent is an overbased substance that can be represented by a compound containing at least one unit of formula (I) or formula (II), wherein each end of the compound has a terminal group of formula (III) or And these end groups are bonded by a divalent bridging group A which may be the same or different:

(I)

(II)

(III)

(IV)

In the formulas (I) to (IV), R ³ is a valence of hydrogen, a hydrocarbyl group or a metal ion; R ² is a hydroxyl or hydrocarbyl group; j is 0, 1 or 2; R ⁶ is hydrogen, a hydrocarbyl group or a hetero-substituted hydrocarbyl group; R ⁴ is hydroxy and R ⁵ and R ⁷ are independently hydrogen, a hydrocarbyl group or a hetero-substituted hydrocarbyl group, or else R ⁵ and R ⁷ are both hydroxy and R ⁴ is hydrogen, A hydrocarbyl group or a hetero-substituted hydrocarbyl group; With the proviso that at least one of R ⁴ , R ⁵ , R ⁶ and R ⁷ is a hydrocarbyl containing 8 or more carbon atoms; These molecules contain, on average, at least one of units (I) or (III) and at least one of units (II) or (IV) and the total number of units (I) and (III) II) and (IV) is from 0.1: 1 to 2: 1. The bivalent bridging group "A", which may be the same or different in each case, includes -CH ₂ - and -CH ₂ OCH ₂ -, either of which may be a formaldehyde or formaldehyde equivalent (eg, paraform, formalin ). ≪ / RTI >

Salicylate derivatives and methods for their preparation are described in more detail in U.S. Patent 6,200,936 and PCT Publication No. WO 01/56968. Salicylate derivatives are predominantly linear rather than macrocyclic, and both structures are believed to be encompassed by the term " salicylate ". According to one embodiment, the salicylate detergent may contain some molecules (before neutralization) represented by the following structure wherein the R ⁸ group is a hydrocarbyl group containing at least eight carbon atoms independently:

The glyoxylate detergent is also a selective overbased material. This is based on anionic groups which, according to one embodiment, can be of the following structure:

Wherein each R is independently an alkyl group containing at least 4 or 8 carbon atoms with the proviso that the total number of carbon atoms present in all of these R groups is at least 12 or 16 or 24, Alternatively, each R may be an olefin polymer substituent. Acidic materials for making overbased glyoxylate detergents are condensation products of hydroxyaromatic materials, such as hydrocarbyl-substituted phenols, with carboxy reactants such as glyoxylic acid or other omega-oxoalkanoic acids. The overbased glyoxyl detergents and methods for their preparation are described in more detail in U.S. Patent No. 6,310,011 and references cited therein.

Another optional overbased detergent is an overbased salicylate, such as an alkali metal or alkaline earth metal salt of a substituted salicylic acid. Salicylic acid can be hydrocarbyl substituted and each substituent contains an average of 8 or more carbon atoms per substituent and 1 to 3 substituents per molecule. These substituents may be polyalkene substituents. According to one embodiment, the hydrocarbyl substituent group may be an alkyl group containing 7 to 300 carbon atoms and having a molecular weight of 150 to 2000. Overbased salicylate detergents and methods for their preparation are disclosed in U.S. Patent Nos. 4,719,023 and 3,372,116.

Other optional overbased detergents may include overbased detergents having a Mannich base structure, as disclosed in U.S. Patent No. 6,569,818.

According to certain embodiments, the hydrocarbyl substituent on the hydroxy-substituted aromatic ring present in said detergents (e.g., phenate, salzigenin, salicylate, glyoxylate or salicylate) is a C ₁₂ aliphatic hydro- (E.g., less than 1%, 0.1%, or 0.01% by weight of the substituent is a C ₁₂ aliphatic hydrocarbyl group). In some embodiments, such hydrocarbyl substituents contain at least 14 or at least 18 carbon atoms.

The amount of detergent in the formulation of the present technology is generally at least 0.1 wt%, such as 0.14 to 4 wt%, or 0.2 to 3.5 wt%, or 0.5 to 3 wt%, or 1 to 2 wt%. Alternate amounts include 0.5 to 4%, 0.6 to 3.5%, 1.0 to 3%, or 1.5 to 2.8%, such as at least 1.0%. One or more overbased detergents may be present, and if more than one is present, the total amount of such materials may be within the aforementioned percent range.

Viscosity Modifier

According to one embodiment, the lubricating composition further comprises at least one viscosity modifier. If present, the viscosity modifier may be present in an amount of from 0.5 wt% to 70 wt%, 1 wt% to 60 wt%, or 5 wt% to 50 wt%, or 10 wt% to 50 wt% of the lubricating composition.

(B) an esterified copolymer of (i) a vinyl aromatic monomer and (ii) an unsaturated carboxylic acid, anhydride or derivative thereof, (c) an ester copolymer of (i) an alpha-olefin; (E) an ethylene-propylene copolymer, (f) a polyisobutene, (g) an ethylene-propylene copolymer, Hydrogenated styrene-isoprene polymer, (h) hydrogenated isoprene polymer, (i) poly alpha-olefin, or (j) mixtures thereof.

(Ii) an esterified copolymer of an unsaturated carboxylic acid, anhydride, or derivative thereof; (c) an esterified copolymer of (i) an alpha - an olefin and (ii) an esterified interpolymer of an unsaturated carboxylic acid, anhydride or derivative thereof, or (d) mixtures thereof.

Dispersant viscosity modifiers (sometimes referred to as DVMs) can be prepared by reacting functionalized polyolefins, such as ethylene-propylene copolymers, functionalized with the reaction products of maleic anhydride and amine, functionalized polymethacrylates with amines, Esterified styrene-maleic anhydride copolymers comprising an amine reacted with a polymer or reacted with an amine may also be used in the compositions of the present invention.

Extreme pressure

Extreme pressure agents include compounds containing boron and / or sulfur and / or phosphorus. Extreme pressure agents may be present in the lubricating composition from 0.0 wt% to 20 wt%, 0.05 wt% to 10 wt%, 0.1 wt% to 8 wt%, or 0.5 wt% to 6 wt% of the lubricating composition.

According to one embodiment, the extreme pressure agent is a sulfur compound. According to one embodiment, the sulfur compound may be a vulcanized olefin, polysulfide or a mixture thereof.

Examples of the vulcanized olefin include propylene, isobutylene, and pentene-derived vulcanized olefins; Organic sulfides and / or polysulfides such as benzyl disulfide; Bis- (chlorobenzyl) disulfide; Dibutyl tetrasulfide; Di-tert-butyl polysulfide; And vulcanized methyl esters of oleic acid, vulcanized alkylphenols, vulcanized dipentenes, vulcanized terpenes, vulcanized Diels-Alder adducts, alkylsulfenyl N'N-dialkyldithiocarbamates; Or mixtures thereof. According to one embodiment, the vulcanized olefin includes a vulcanized olefin derived from propylene, isobutylene, pentene or a mixture thereof.

According to one embodiment, the extreme pressure sulfur compounds include dimercaptothiadiazole or derivatives or mixtures thereof. Examples of dimercaptothiadiazoles include 2,5-dimercapto-1,3,4-thiadiazole or hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole or oligomers thereof . Oligomers of hydrocarbyl-substituted 2,5-dimercapto-1,3,4-ditaazoles generally have a sulfur-sulfur bond between 2,5-dimercapto-1,3,4-thiadiazole units To form oligomers or derivatives of at least two thiadiazole units. Suitable 2,5-dimercapto-1,3,4-thiadiazole-derived compounds are 2,5-bis (tert-nonyldithio) -1,3,4-thiadiazole or 2-tert- 5-mercapto-1,3,4-thiadiazole.

The number of carbon atoms present in the hydrocarbyl substituent of the hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole is from 1 to 30, from 2 to 20, or from 3 to 16 .

According to one embodiment, the extreme pressure agent comprises a boron-containing compound. The boron-containing compounds include borate esters (sometimes referred to as borate epoxides in some embodiments), borated alcohols, borated dispersants, or mixtures thereof. According to one embodiment, the boron-containing compound may be a borate ester or a borated alcohol.

The borate ester can be prepared by reacting a boron compound with at least one compound selected from an epoxy compound, a halohydrin compound, an epihalohydrin compound, an alcohol, and a mixture thereof. Alcohols include dihydric alcohols, trihydric alcohols or higher alcohols, and according to one aspect, the hydroxy groups must be on vicinal carbon atoms, i.e. vicinal.

Suitable boron compounds for preparing the borate ester are selected from the group consisting of boric acid (including metaboric acids, HBO ₂ , orthoboric acid, H ₃ BO ₃ and tetraboric acid, H ₂ B ₄ O ₇ ), boron oxide, boron trioxide and alkyl borates ≪ / RTI > The boric acid ester may also be prepared from a boron halide.

According to one embodiment, suitable borate ester compounds include tripropylborate, tributylborate, tripentylborate, trihexylborate, triheptylborate, trioctylborate, trinonylborate and tridecylborate.

According to one embodiment, the boric ester compound comprises tributyl borate, tri-2-ethylhexyl borate or mixtures thereof.

According to one embodiment, the boron-containing compound is a borated dispersant, which is generally derived from an N-substituted long-chain alkenyl succinimide. According to one embodiment, the borated dispersant comprises polyisobutylene succinimide. The borated dispersants are described in more detail in U.S. Pat. Nos. 3,087,936 and 3,254,025.

According to one embodiment, the borated dispersant may be used with a sulfur compound or a borate ester.

According to one embodiment, the extreme pressure agent is other than the borated dispersant.

The number average molecular weight of the hydrocarbon from which the long chain alkenyl group is derived may range from 350 to 5000, 500 to 3000, or 550 to 1500. The long-chain alkenyl group may have a number average molecular weight of 550, 750 or 950 to 1000.

The N-substituted long chain alkenyl succinimides can be prepared by reacting a variety of agents, including boric acid (e.g., metaboric acid, HBO ₂ , orthoboric acid, H ₃ BO ₃ and tetraboric acid H ₂ B ₄ O ₇ ), boron oxide, boron trioxide, Is used. According to one embodiment, the borating agent is boric acid which can be used alone or in combination with other borating agents.

The borated dispersant may be prepared by combining a boron compound with an N-substituted long chain alkenyl succinimide and heating them at a suitable temperature, for example, from 80 캜 to 250 캜, or from 90 캜 to 230 캜, or from 100 캜 to 210 캜, And heating until the desired reaction occurs. The molar ratio of the boron compound to the N-substituted long chain alkenyl succinimide may range from 10: 1 to 1: 4, 4: 1 to 1: 3; Or the molar ratio of boron compound to N-substituted long chain alkenyl succinimide may be 1: 2.

An inert liquid may be used to carry out the reaction. The liquid may comprise toluene, xylene, chlorobenzene, dimethylformamide or mixtures thereof.

According to one embodiment, the dispersing agent may be a post-treated dispersing agent. The dispersant may optionally be post-treated with a dimercaptothiadiazole in the presence of one or more of phosphorus compounds, dicarboxylic acids of aromatic compounds, and boronating agents.

According to one embodiment, the post-treated dispersant can be prepared by partial hydrolysis of the ester by heating the alkenyl succinimide or succinimide detergent with the phosphorus ester and water. This type of post-treated dispersant is disclosed, for example, in U.S. Patent 5,164,103.

According to one embodiment, the post-treated dispersant can be produced by preparing a mixture of a dispersant and a dimercaptothiadiazole, and heating the mixture to about 100 ° C or higher. This type of post-treated dispersant is disclosed, for example, in U.S. Patent 4,136,043.

According to one embodiment, the dispersant is post-treated to form a dispersion comprising (i) a dispersant, generally a succinimide, (ii) 2,5-dimercapto-1,3,4-thiadiazole or hydrocarbyl substituted 2 , 5-dimercapto-1,3,4-thiadiazole, or an oligomer thereof, (iii) a boronating agent (similar to that described above); And (iv) a dicarboxylic acid (usually terephthalic acid) of an aromatic compound, optionally selected from the group consisting of 1,3 diacids and 1,4-diacids, or (v) an acid compound, such as phosphoric acid or phosphorous acid, (Ii), (iii) and, if desired, (iv), or, if desired, the oil, which is soluble in the oil of lubricating viscosity, (v). < / RTI > This type of post-treated dispersant is disclosed, for example, in International Application WO 2006/654726 A.

Examples of suitable dimercaptothiadiazoles include 2,5-dimercapto-1,3,4-thiadiazole or hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole do. According to various embodiments, the number of carbon atoms present in the hydrocarbyl-substituent group includes from 1 to 30, from 2 to 25, from 4 to 20, or from 6 to 16 carbon atoms. Examples of suitable 2,5-bis (alkyl-dithio) -1,3,4-thiadiazoles include 2,5-bis (tert-octyldithio) -1,3,4-thiadiazole 2,5 (Tert-nonyldithio) -1,3,4-thiadiazole, 2,5-bis (tert-decyldithio) -1,3,4-thiadiazole, 2,5-bis (Undecyldithio) -1,3,4-thiadiazole, 2,5-bis (tert-dodecyldithio) -1,3,4-thiadiazole, 2,5- Decyldithio) -1,3,4-thiadiazole, 2,5-bis (tert-tetradecyldithio) -1,3,4-thiadiazole, 2,5-bis (tert- O) -1,3,4-thiadiazole, 2,5-bis (tert-hexadecyldithio) -1,3,4-thiadiazole, 2,5-bis (tert-heptadecyldithio) (Tert-octadecyldithio) -1,3,4-thiadiazole, 2,5-bis (tert-nonadecyldithio) -1 , 3,4-thiadiazole or 2,5-bis (tert-eicosyldithio) -1,3,4-thiadiazole or oligomers thereof.

Friction modifiers include reaction products of fatty acid esters, amine salts of phosphoric acid esters, fatty acid esters of fatty carboxylic acids in reaction with guanidine, aminoguanidine, urea or thiourea, and their salts, fatty amines, fatty hydroxyamines, borated phospholipids , Fatty acid esters, fatty acid phosphates, fatty acid amides, fatty epoxides, borated fatty epoxides, alkoxylated fatty amines, borated alkoxylated fatty amines, fatty polyethers, metal salts of fatty acids, or fatty Imidazolines, condensation products of carboxylic acids and polyalkylene-polyamines, fatty amides, fatty tartrimides and fatty oxazolines.

According to one embodiment, the lubricating composition may contain other phosphorus- or sulfur-containing antiwear agents in addition to the compounds described as extreme pressure agents of amine salts of phosphoric acid esters described above. Examples of antiwear agents include non-ionic compounds (generally compounds having atoms with an oxidation state of +3 or +5), metal dialkyldithiophosphates (typically zinc dialkyldithiophosphates), metal mono- Or di-alkyl phosphate (generally zinc phosphate), or mixtures thereof.

Non-ionic phosphorus compounds include phosphite esters, phosphate esters, or mixtures thereof. A more detailed description of the non-ionic phosphorus compounds is given in column 6, column 103, column 8, line 8, Containing abrasive compound may be included in the lubricant composition at from about 100 to about 2000 ppm, from about 500 to about 1800 ppm, or from about 700 to about 1500 or 1600 ppm.

According to one embodiment, the lubricating composition of the present invention further comprises a dispersing agent. Dispersing agents include, but are not limited to, succinimide dispersants (e.g., N-substituted long chain alkenyl succinimides), Mannich dispersants, ester-containing dispersants, condensation products of fatty hydrocarbyl monocarboxyl acylating agents with amines or ammonia, , A hydrocarbyl-amine dispersant, a polyether dispersant, or a polyether amine dispersant.

According to one embodiment, the succinimide dispersant comprises polyisobutylene-substituted succinimide, and the polyisobutylene from which the dispersant is derived may have a number average molecular weight of 400 to 5000, or 950 to 1600.

The succinimide dispersant and its preparation method are disclosed in US Patent Nos. 3,172,892, 3,219,666, 3,316,177, 3,340,281, 3,351,552, 3,381,022, 3,433,744, 3,444,170, 3,467,668, 3,501,405, 3,542,680, 3,576,743, 3,632,511, 4,234,435, Re 26,433 and 6,165,235,7,238,650, 355 < / RTI > 895A.

Suitable ester-containing dispersants are generally high molecular weight esters. This material is described in more detail in U.S. Pat. No. 3,381,022.

According to one embodiment, the dispersant comprises a borated dispersant.

Generally, the borated dispersant comprises a succinimide dispersant, such as polyisobutylene succinimide, wherein the polyisobutylene from which the dispersant is derived may have a number average molecular weight ranging from 400 to 5000. The borated dispersant is described in more detail in the extreme pressure agent description above.

The dispersant may be added to the described lubricant composition in the range of about 0.1 to 5 wt%, or about 0.5 to about 4 wt%, or especially about 1.0 to about 2.5 or 3 wt%.

Corrosion inhibitors include condensation products of fatty acids and polyamines such as amides, imidazolines, amines, fatty amines, 1-amino-2-propanol, octylamine octanoate, dodecenyl succinic acid or anhydrides and / or oleic acid.

Examples of the metal deactivator include derivatives of benzotriazole (generally, tolyltriazole), derivatives of 1,2,4-triazole, benzimidazole, 2-alkyldithiobenzimidazole, thiadiazole or 2- Benzothiazole. Metal deactivators may also be described as corrosion inhibitors.

Foam inhibitors include copolymers of ethyl acrylate and 2-ethylhexyl acrylate and, optionally, vinyl acetate. Also included are siloxanes, generally polydimethylsiloxanes.

The anti-emulsifier includes trialkyl phosphates and various polymers and copolymers of ethylene glycol, ethylene oxide, propylene oxide or mixtures thereof.

Pour point depressants include esters of maleic anhydride-styrene, polymethacrylates, polyacrylates or polyacrylamides.

Seal expanders include Exxon Necton-37 (FN 1380) and Exxon Mineral Seal Oil (FN 3200).

Industrial availability

The built-in lubricant of the limiting slip differential is generally different from the lubricant supplied to the manual transmission or automatic transmission fluid.

An axle gear can have one of many different types of differentials. The differential generally has three main functions. The first function is to deliver engine power to the wheel. The second function acts as the last gear deceleration of the vehicle, reducing the speed of rotation from the transmission to the wheel. The third function is to transmit power to the wheel while allowing the wheel to rotate at a different speed. Many differentials are known and include, for example, an open differential, a clutch limiting slip differential, a viscous coupling differential, a Torsen differential, and a locking differential. All of these differentials can generally be referred to as axle gears.

Axle gears generally require a lubricant. This lubricant formulation depends on the type of axle gear and the operating conditions of the axle gear. For example, an open differential axle gear is considered to require wear resistance and / or extreme pressure additives. The limit slip differential also requires a friction modifier because spring packs and clutch packs are generally present in addition to the open differential (known from many axle fluids). The clutch pack may contain one or more reaction plates (often made of steel) and one or more friction plates. Friction plates are known and can be made of a variety of materials including paper, carbon, graphite, steel and composites.

Suitable lubricating compositions for limiting slip differentials can have a sulfur content ranging from 0.3 wt% to 5 wt%, 0.5 wt% to 5 wt%, 0.5 wt% to 3 wt%, 0.8 wt% to 2.5 wt% or 1 wt% to 2 wt% have.

According to one aspect, a lubricating composition suitable for a limiting slip differential may be a fully formulated fluid.

According to one aspect, a lubricating composition suitable for a limiting slip differential may be a top treat concentrate.

When the lubricating composition is in the form of a toptreate concentrate, the concentrate may be present in an amount ranging from about 0.1 wt% to 10 wt%, alternatively 0.2 wt% to 7 wt%, 0.25 wt% to 2, 3, 4 Or 5%, or especially 0.25 to 1 wt%, or 1.0 to 3.0 wt%, based on the weight of the active material.

According to one aspect of the invention, a method is provided for providing a limited slip capability, including introducing the lubricating composition disclosed herein to a differential, and operating the differential.

The lubricant compositions and methods disclosed herein may be suitable for limiting slip systems with one or more different sheet materials. For example, the plate material can be a system using a composite plate type such as steel, paper, ceramic, carbon fiber and ceramic-on-ceramic, carbon fiber in paper or steel on paper.

The amount of each chemical component described is an amount based on the active chemical that is not otherwise mentioned, in the amount excluded from any solvent or diluent oil that may normally be present in a commercially available material. However, unless stated otherwise, each chemical or composition mentioned herein should be construed as being a commercial grade substance that may contain isomers, by-products, derivatives and other such substances known to be commonly present in commercial grades .

It is known that some of the materials described above may interact in the final formulation so that the ingredients of the final formulation may differ from the initially added ingredients. For example, metal ions (e.g., metal ions of a detergent) can migrate to other acidic or anionic sites of other molecules. The product thus formed, for example, the product formed when using the lubricant composition of the present invention for the intended use, may not be easy to explain. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; The present invention encompasses a lubricant composition prepared by mixing the aforementioned components.

Example

Manufacturing example  One( EX1 );

A 2L four-necked flask equipped with a thermocouple was charged with aminopropyloleylamine (682 g) and heated. Oleic acid (621.5 g) was added to the amine over 15 minutes via an addition funnel. The reaction mixture was heated to reflux and the distillate was collected. The final product was a white waxy solid at room temperature.

Axle  slush

Comparative Example 1 (CE1) is a commercial axle fluid that has the formulation of Table 1 and does not contain an additional limiting slip friction modifier.

ingredient wt% - based on active substance Oil of lubricating viscosity 65.98 Extreme pressure 5.38 Viscosity modifier 25.06 Corrosion inhibitor 0.22 Antiwear agent 1.66 Dispersant 1.53 Defoamer 0.04 Friction modifier 0.13

Example 1 (IE1) of the present invention is a commercially available axle fluid that has been treated with 1.8 wt% of Preparation Example 1.

ingredient wt% - based on active substance CE1 96.0 Oils with additional lubrication viscosity 2.2 Production Example 1 1.8

The test lubricant was prepared by adding one of the materials of the Examples given in the following tables to the base formulation given. The lubricant containing EX1 was evaluated in the Full-Scale Low-Velocity Friction Apparatus (FSLVFA). This device uses clutch specimens as defined in SAE Paper 2010-01-2231. This test is carried out with varying speed, temperature and pressure. This test consists of an evaluation of the friction performance after the start and the 17 hour endurance step. The commissioning step is carried out at 90 ° C oil temperature, 16 rpm, and 7070 N load for 10 minutes. This step adjusts the clutch system for preliminary durability performance evaluation. The preliminary durability performance is evaluated by raising the speed of 0 to 5 rpm within 5 seconds and then returning to 0 again. The load is set at two levels, 3535N and 7070N, which corresponds to the range of compressive loads of the axle imposed by the axle's inner clutch pack. The two loads were evaluated at three oil temperatures: 40 캜, 90 캜 and 120 캜. The sample clutch pack undergoes a durability step that includes operating the test rig at 120 占 폚 oil temperature, 7070 N load and 16 rpm for 17 hours. A post-durability evaluation is then performed using the same conditions as the preliminary test evaluation. A more detailed description of the test procedure is provided in SAE Paper 2010-01-2231. The table below shows the post-endurance grade and curvature of the NVH (at 5 rpm). The data obtained are as follows:

NVH at < RTI ID = 0.0 > 5 C <

^* a - Miba ™ MC-631

^* b - Hoerbiger ™ HC-100

^* c - FCC ™ 3312

Remark:

Noise, vibration, and haze ( NVH ) at 5 rpm are the standard deviation of the torque signal based on the moving average of the torque signal for 2 seconds at 5 rpm. The high NVH grade represents the occurrence of "stick-slip" on the friction surface. When the plates "stick", the torque surges, and when the plates "slip" the torque falls. NVH represents the amplitude of the torque signal and is independent of the shape of the torque signal. Good FM candidates should exhibit low NVH at 5 rpm.

Curvature refers to the shape of the torque signal that is thought to be related to the difference between the static and dynamic friction coefficients. The curvature is the average difference between the torques during a two second hold at 5 rpm versus the torque versus when the plates stand apart. Positive curvature means that the torque signal is concave during the sweep (warping down). Negative curvature means that the torque signal is convex during sweep (upward warp). The ideal curvature is close to zero, which means that the torque signal is flat along all speeds. A slightly negative curvature value is acceptable, but a high positive curvature value is undesirable.

Each of the foregoing documents is incorporated herein by reference. The citation of any document does not imply that this document is in the nature of prior art or constitutes a general knowledge of those skilled in the art under any jurisdiction. It should be understood that the term "about" is used throughout this specification to refer to amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, all of which are expressly stated, unless the embodiment or the other is explicitly stated. It is to be understood that the amounts, ranges and ratio limits of the upper and lower limits set forth herein may be combined independently. Likewise, the ranges and amounts of each component of the invention may be used with ranges or amounts of any other components.

Claims (9)

(1) an N-substituted 1,3-diaminopropane derived from a C _{8 -28} amine and (2) a condensation product of a C _{8 -28} acid ≪ / RTI > wherein the lubricant is a lubricant for limited slip differentials containing at least one oil soluble compound containing at least one oil soluble compound. The method of claim 1 wherein the condensation product is the formula R'NH (CH _{2) 3} NHCOR "is a compound (wherein, R 'is a N- substituent derived from a C _{8 -28} of the amine (1), -COR" is ( 2) C _{8 -28} acid. The lubricant according to claim 1 or 2, wherein the C _{8 -28} amine of (1) is a fatty amine and the C _{8 -28} acid of (2) is at least one of fatty acid or fatty acid chloride. 4. A lubricant according to any one of claims 1 to 3, wherein R 'is derived from a C ₁₈ fatty amine and -COR "is derived from a C ₁₈ fatty acid. 5. A lubricant according to any one of claims 1 to 4, wherein R 'is derived from at least one of soybean amine, oleyl amine, tallow amine or cocoamine. 6. A compound according to any one of claims 1 to 5, wherein -COR "is derived from myristic acid, palmitic acid, beheic acid, eruicic acid, oleic acid, stearic acid, linoleic acid and lauric acid Phosphorus lubricant. The lubricant according to any one of claims 1 to 6, which contains a condensation product of oleic acid with N-oleyl-1,3-diaminopropane. A method for providing a limiting slip capability, comprising the steps of: introducing the lubricating composition of any one of claims 1-7 into a limiting slip differential and operating the limiting slip differential. Use of a lubricant according to any one of claims 1 to 7 for use in limiting slip differential performance in a limiting slip differential.