CA3087692A1

CA3087692A1 - Boron containing automotive gear oil

Info

Publication number: CA3087692A1
Application number: CA3087692A
Authority: CA
Inventors: Tomoya HIGUCHI
Original assignee: Lubrizol Corp
Current assignee: Lubrizol Corp
Priority date: 2018-01-04
Filing date: 2019-01-02
Publication date: 2019-07-11
Also published as: CN111615548A; EP3735455A1; EP3735455B1; WO2019136052A1; JP2021509929A; US20200369978A1

Abstract

The disclosed technology relates to an automotive gear oil, which may be used, for example, in heavy duty manual transmissions and axles, and includes an oil of lubricating viscosity, 1wt% or less of a dispersant, and at least one boron containing compound.

Description

2 TITLE
BORON CONTAINING AUTOMOTIVE GEAR OIL
BACKGROUND OF THE INVENTION
[0001] The disclosed technology relates to an automotive gear oil, which may be used, for example, in manual transmissions and axles, and includes an oil of lubricating viscosity, lwt% or less of a dispersant, and at least one boron containing compound.
The automotive gear oil is particularly useful as a single lubricant to lubricate both the transmission and the axle.
[0002] Deposits of decomposition products such as carbon, varnish and sludge cause serious problems in gearboxes. The tendency towards decomposition products is particularly strong among synthetic automotive gear oils which have long drain intervals. As such, cleanliness is a mandatory requirement in automotive gear oils, and particularly modern automotive gear oils based on synthetic base oils.

[0003] Most modern automotive gear oils contain dispersants that help maintain .. the cleanliness of the oil. However, dispersants were not always included in automo-tive gear oil products. With the tendency towards more synthetics, there is a need to provide improved cleanliness to some of the older automotive gear oil formulations, without losing the performance that the automotive gear oil provided.
Unfortunately, it has been found that the addition of dispersant to an automotive gear oil can have a detrimental effect on the frictional characteristics of the oil. As frictional character-istics are a set parameter for a given oil, a solution is needed to balance the need for cleanliness while maintaining proper friction.
SUMMARY OF THE INVENTION

[0004] The present technology solves the problem of balancing cleanliness with frictional properties in automotive gear oils by providing an automotive gear oil for lubricating an automotive gear having an oil of lubricating viscosity, lwt% or less of a dispersant, and at least one boron containing compound in an amount sufficient to provide from about 75ppm to about 500 ppm of boron to the automotive gear oil.

[0005] It has been found that the presence of the boron-containing compound not only enhances the cleansing ability of any dispersant present, but also suppresses any harmful effects to the oil's frictional characteristics from the dispersant.

[0006] In an embodiment, the dispersant in the automotive gear oil can be a suc-cinimide dispersant.

[0007] In an embodiment, the at least one boron-containing compound can be a borate ester of formula I, RO
OR
RI
wherein each R, independently, is a C3 to C12 alkyl,

[0008] In some embodiments, the borate ester can be present from about 0.2 to 2.0 wt % of the automotive gear oil.

[0009] In embodiments, the automotive gear oil can also include at least one .. phosphorous containing compound present in an amount to deliver 100 to 1500 ppm of phosphorus to the automotive gear oil. In embodiments, the phosphorous contain-ing compound can be at least one of: (1) a C3-8 hydrocarbyl phosphite, (2) a phos-phite ester composition that comprises the reaction product of a monomeric phos-phorous acid or an ester thereof with at least two alkylene diols, or (3) mixtures of (1) and (2).

[0010] The automotive gear oil can also include 0.01 wt % to 0.5 wt %
of a di-mercaptothiadiazole or derivative thereof, and/or 0.1 wt % to 5 wt % of a poly(meth)acrylate ester polymer viscosity modifier.

[0011] In an embodiment, the automotive gear oil can have a kinematic viscosity at 100 C of from 8 cSt to 24 cSt.

[0012] The disclosed technology also includes a method of lubricating an auto-motive gear by supplying to the automotive gear the automotive gear oil composi-tion, and operating the automotive gear. The automotive gear can be, for example, in a manual transmission, on an axle, and/or on a differential.
DETAILED DESCRIPTION OF THE INVENTION

[0013] Various preferred features and embodiments will be described below by way of non-limiting illustration.

[0014] One aspect of the present technology is an automotive gear oil.
The auto-motive gear oil can be employed to provide lubrication to the gears of automotive vehicles, such as, for example, manual transmissions, axles and differentials.
The composition can include, among other things, an oil of lubricating viscosity, 1 wt%
or less of a dispersant, and at least one boron-containing compound.
Oils of Lubricating Viscosity

[0015] Oils of lubricating viscosity may also be defined as specified in the Amen-can Petroleum Institute (API) Base Oil Interchangeability Guidelines (2011).
The five base oil groups are as follows: Group I (sulfur content >0.03 wt %, and/or <90 wt %
saturates, viscosity index 80 to less than 120); Group II (sulfur content <0.03 wt %, and >90 wt % saturates, viscosity index 80 to less than 120); Group III
(sulfur content <0.03 wt %, and >90 wt % saturates, viscosity index >120); Group IV (all polyalpha-olefins (PA0s)); and Group V (all others not included in Groups I, II, III, or IV). The oil of lubricating viscosity may also be a Group II+ base oil, which is an unofficial API
category that refers to a Group II base oil having a viscosity index greater than or equal to 110 and less than 120, as described in SAE publication "Design Practice:
Passenger Car Automatic Transmissions," fourth Edition, AE-29, 2012, page 12-9, as well as in US 8,216,448, column 1 line 57. The oil of lubricating viscosity may also be a Group III+ base oil, which, again, is an unofficial API category that refers to a Group III base oil having a viscosity index of greater than 130, for example 130 to 133 or even greater than 135, such as 135-145. Gas to liquid ("GTL") oils are sometimes considered Group III+ base oils.

[0016] The oil of lubricating viscosity may be an API Group IV oil, or mixtures thereof, i.e., a polyalphaolefin. The polyalphaolefin may be prepared by metallocene catalyzed processes or from a non-metallocene process. The oil of lubricating viscosity may also comprise an API Group I, Group II, Group III, Group IV, Group V oil or mixtures thereof. Often the oil of lubricating viscosity is an API Group I, Group II, Group II+, Group III, Group IV oil or mixtures thereof. Alternatively the oil of lubri-cating viscosity is often an API Group II, Group II+, Group III or Group IV
oil or mixtures thereof. Alternatively the oil of lubricating viscosity is often an API Group II, Group II+, Group III oil or mixtures thereof.

[0017] The oil of lubricating viscosity, or base oil, will overall have a kinematic viscosity at 100 C of 2 to 10 cSt or, in some embodiments 2.25 to 9 or 2.5 to 6 or 7 or 8 cSt, as measured by ASTM D445. Kinematic viscosities for the base oil at 100 C
of from about 3.5 to 6 or from 6 to 8 cSt are also suitable.

[0018] The amount of the oil of lubricating viscosity present is typically the balance remaining after subtracting from 100 wt % the sum of the amount of the performance additives in the composition. Illustrative amounts may include 50 to 99 percent by weight, or 60 to 98, or 70 to 95, or 80 to 94, or 85 to 93 percent.

[0019] The lubricating composition may be in the form of a concentrate and/or a fully formulated lubricant. If the lubricating composition of the invention is in the form of a concentrate (which may be combined with additional oil to form, in whole or in part, a finished lubricant), the ratio of the components of the invention to the oil of lubricating viscosity and/or to diluent oil include the ranges of 1:99 to 99:1 by weight, or 80:20 to 10:90 by weight.
Dispersant

[0020] The automotive gear oil will contain 1 wt% or less of a dispersant. Many types of dispersants are known in the art.

[0021] "Carboxylic dispersants" are reaction products of carboxylic acylating agents (acids, anhydrides, esters, etc.) containing at least about 34 and preferably at least about 54 carbon atoms with nitrogen containing compounds (such as amines), organic hydroxy compounds (such as aliphatic compounds including monohydric and polyhydric alcohols, or aromatic compounds including phenols and naphthols), and/or basic inorganic materials. These reaction products include imide, amide, and ester reaction products of carboxylic ester dispersants.

[0022] The carboxylic acylating agents include fatty acides, isoaliphatic acids (e.g. 8-methyl-octadecanoic acid), dimer acids, addition dicarboxylic acids (addition (4+2) and 2+2) products of an unsaturated fatty acid with an unsaturated carboxylic reagent), trimer acids, addition tricarboxylic acids (Empol 1040, Hystrene and Unidyme 60), and hydrocarbyl substituted carboxylic acylating agents (from olefins and/or polyalkenes). In one embodiment, the carboxylic acylating agent is a fatty acid. Fatty acids generally contain from about 8 up to about 30, or from about 12 up to about 24 carbon atoms. Carboxylic acylating agents are taught in U.S.
Pa-tents No. 2,444,328, 3,219,666 and 4,234,435, the disclosures of which is hereby .. incorporated by reference.

[0023] The amine may be a mono- or polyamine. The monoamines generally have at least one hydrocarbyl group containing from 1 to about 24 carbon atoms, or from 1 to about 12 carbon atoms. Examples of monoamines include fatty (C8-30) amines (Armeens), primary ether amines (SURFAMCD amines), tertiary-aliphatic primary amines ("Primenes"), hydroxyamines (primary, secondary or tertiary alkanol amines), ether N-(hydroxyhydrocarbyl) amines, and hydroxyhydrocarbyl amines 5 ("Ethomeens" and "Propomeens). The polyamines include alkoxylated diamines (Ethoduomeens), fatty diamines ("Duomeens"), alkyl enepolyamines (ethylenepoly-amines), hydroxy-containing polyamines, polyoxyalkylene polyamines (Jeffamines), condensed polyamines (a condensation reaction between at least one hydroxy com-pound with at least one polyamine reactant containing at least one primary or sec-ondary amino group), and heterocyclic polyamines. Useful amines include those dis-closed in U.S. Patent 4,234,435 (Meinhart) and U.S. Patent 5,230,714 (Steckel) which are incorporated herein by reference.

[0024] An example carboxylic dispersant can include, for example, "succinimide dispersants," prepared by the reaction of a hydrocarbyl-substituted succinic acylating agent with an amine such as a polyamine.

[0025] The hydrocarbyl-substituted succinic acylating agents include succinic ac-ids, halides, esters, and anhydrides, preferably, acids, esters or anhydrides, more pref-erably anhydrides. The hydrocarbyl group generally contains an average of at least about 8, or about 30, or about 35 up to about 350, or to about 200, or to about 100 carbon atoms. In one embodiment, the hydrocarbyl group is derived from a polyal-kene, such as, for example, polyisobutylene, generally having a number average mo-lecular weight of from 100 to 5000, or 500 to 4000 or 1000 to 3000.

[0026] The amine which reacts with the succinic acylating agent may be a poly-amine. The polyamine may be aliphatic, cycloaliphatic, heterocyclic or aromatic.
Examples of the polyamines include alkylene polyamines, hydroxy containing poly-amines, arylpolyamines, and heterocyclic polyamines.

[0027] "Amine dispersants" are reaction products of relatively high molecular weight aliphatic halides and amines, preferably polyalkylene polyamines.

[0028] "Mannich dispersants" are the reaction products of alkyl phenols in which the alkyl group contains at least about 30 carbon atoms with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines).

[0029] Post-treated dispersants are obtained by reacting carboxylic, amine or Mannich dispersants with reagents such as dimercaptothiadiazoles, urea, thiourea, carbon disulfide, aldehydes, ketones, carboxylic acids, hydrocarbon-substituted suc-cinic anhydrides, nitriles, epoxides, boron compounds, phosphorus compounds or the like.

[0030] Polymeric dispersants are interpolymers of oil-solubilizing monomers such as decyl methacrylate, vinyl decyl ether and high molecular weight olefins with monomers containing polar substituents, e.g., aminoalkyl acrylates or acrylamides and poly-(oxyethylene)-substituted acrylates.

[0031] Dispersants and dispersant chemistry is well-known in the art. The dis-persants suitable for use in the automotive gear oils described herein are not particu-larly limited. Rather, the level of dispersant may be minimized in view of the use of the boron-containing compounds, as described below.

[0032] Mixtures of the foregoing dispersants can also be used. The dispersant can have a nitrogen content of greater than or equal to about 11,000 ppm by weight of the dispersant, or greater than or equal to about 11,500ppm or greater than or equal to about 12,000 ppm.

[0033] The total amount of dispersant or dispersants, whether post-treated or not (e.g., borated or non-borated) or combinations thereof, in the compositions, may be, for instance, 0.01 to 1 percent by weight, or, for example, 0.025 to 0.9 percent or 0.05 to 0.8 weight percent of the final blended fluid formulation, although in a concentrate, the amounts will be proportionately higher. In an embodiment, the automotive gear oil may be substantially free of the above-described dispersant, or even completely free of the above described dispersant.
Boron-Containing Compound

[0034] The automotive gear oil can contain a boron-containing compound in an amount sufficient to provide from about 75ppm to about 500 ppm of boron to the automotive gear oil, or from about 85 to about 450 ppm or about 95 to about 350 ppm boron, or from about 100 to about 400ppm boron to the automotive gear oil.

[0035] The boron can be delivered by many types of boron-containing com-pounds. The boron can, for example, come from a borated dispersant.

[0036] The boron-containing compound can include boron containing friction modifiers, such as, for example, borated fatty epoxides, borated glycerol esters, and borated alkoxylated fatty amines.

[0037] The boron containing compound can also include borated detergents. The borated detergents can include, for example, overbased borated materials, which are described in U.S. Patents 5,403,501 and 4,792,410.

[0038] The boron containing compound can also include a borate ester.
The bo-rate ester may be a compound represented by one or more of the formulae:
RO I, or \B---"OR
RI
RO OR III, or OR V, O-=____ -O
RO OR
wherein each R can be, independently a hydrocarbyl group, as that term is defined herein, and any two adjacent R groups may together form a cyclic group.
Mixtures of two or more of the foregoing may be used. The total number of carbon atoms in the R groups in each formula should be sufficient to render the compound soluble in the oil of lubricating viscosity. Generally, the total number of carbon atoms in the R
groups is at least about 3, and in one embodiment at least about 5, and in one embod-iment at least about 8. There is no limit to the total number of carbon atoms in the R
groups that is required, but a practical upper limit is about 400 or about 500 carbon atoms.

[0039] In embodiments, each R can independently be a hydrocarbyl group con-taining 1 to 14, or from 2 to 13 or even 3 to 10 or 12 carbon atoms, provided the sum total number of carbon atoms in all R is 3 or more, preferably 4 or more and even more preferably 6 or more. In some embodiments, each R, independently, can be a C3 to C22, or C3 to C18, or C3 to C12 alkyl. Examples of useful R groups include isopropyl, n-butyl, isobutyl, amyl, 4-methyl-2-pentyl, 2-ethyl-1-hexyl, isooctyl, decyl, dodecyl, 2-propylheptyl, tetradecyl, 2-pentenyl, dodecenyl, phenyl, naphthyl, alkylphenyl, and the like. Others can be found, for example, in W02017/083548.

[0040] Suitable examples of the borate ester include, for example, tripropyl bo-rate, tributyl borate, tripentyl borate, trihexyl borate, triheptyl borate, trioctyl borate, trinonyl borate and tridecyl borate. Other borate ester examples can include, for ex-ample, the compound of formula I, wherein each R is, independently, a C3 to C22, or C3 to C18, or C3 to C12 alkyl, such as, for example, tri-2-ethylhexyl borate, tris(2-propylheptyl) borate and mixtures thereof. In an embodiment the borate ester can be a C8 borate ester, or a Cio borate ester. In one embodiment the borate ester can be tris(2-propylheptyl) borate. In some embodiments the borate ester can be tri-2-ethylhexyl borate.

[0041] In one embodiment, the borated ester can be represented by the formula B(005H11)3 or B(0C4H9)3. In one embodiment, the borated ester can be tri-n-butyl borate.

[0042] In one embodiment, the borated ester can be a phenolic compound repre-sented by the formula HO
= R5¨ 0¨R6-0¨B-0R4 wherein in formula VII: R1, R2, R3 and R4 are independently hydrocarbyl groups of 1 to about 12 carbon atoms; and R5 and R6 are independently alkylene groups of 1 to about 6 carbon atoms, and in one embodiment about 2 to about 4 carbon atoms, and in one embodiment about 2 or about 3 carbon atoms. In one embodiment, Ri and independently contain 1 to about 6 carbon atoms, and in one embodiment each is a t-butyl group. In one embodiment, R3 and R4 are independently hydrocarbyl groups of about 2 to about 12 carbon atoms, and in one embodiment about 8 to about 10 carbon atoms. In one embodiment, R5 and R6 are independently --CH2CH2 -- or --

[0043] In one embodiment, the borated ester can be a compound represented by the formula:

R
-0-/0/(3 \04R
wherein in formula IX, each R is independently hydrogen or a hydrocarbyl group.
Each of the hydrocarbyl groups may contain from 1 to about 12 carbon atoms, and in one embodiment 1 to about 4 carbon atoms. An example is 2,2'-oxy-bis-(4,4,6-trime-thy1-1,3,2-dioxaborinane).

[0044] The borate ester may be employed in the automotive gear oil at about 0.2 or 0.3 to about 2.0 wt.% based on the weight of the automotive gear oil, or in some cases about 0.35 to 2.0 wt.%, and in one embodiment from about 0.25 to about 1.0 wt.%, and in one embodiment about 0.25 to about 0.75 wt.%.
Other Additives

[0045] The automotive gear oil can contain further additives aside from the dis-persant and boron-containing compound.
Phosphorus Containing Compound

[0046] The automotive gear oil can additionally contain a phosphorous containing compound. The phosphorus-containing compound may be an acid, salt or ester. In one embodiment the phosphorus-containing compounds are in the form of a mixture of two or three, or two to four (typically two or three) phosphorus-containing com-pounds.

[0047] In some embodiments the phosphorus-containing compound is a phos-phite. Suitable phosphites include those having at least one hydrocarbyl group with 5 3 or 4 or more, or 8 or more, or 12 or more, carbon atoms. The phosphite may be a mono-hydrocarbyl substituted phosphite, a di-hydrocarbyl substituted phosphite, or a tri-hydrocarbyl substituted phosphite.

[0048] In one embodiment the phosphite is sulphur-free i.e., the phosphite is not a thiophosphite.
10 [0049] The phosphite may be represented by the formulae:
RO H XI
ROP%

wherein at least one R may be a hydrocarbyl group containing at least 3 carbon atoms and the other R groups may be hydrogen. In one embodiment, two of the R groups are hydrocarbyl groups, and the third is hydrogen. In one embodiment every R
group is a hydrocarbyl group, i.e., the phosphite is a tri-hydrocarbyl substituted phosphite.
The hydrocarbyl groups may be alkyl, cycloalkyl, aryl, acyclic or mixtures thereof.
[0050] The R hydrocarbyl groups may be linear or branched, typically linear, and saturated or unsaturated, typically saturated.
[0051] In one embodiment, the phosphorus-containing compound can be a hydrocarbyl phosphite, or mixtures thereof, i.e., wherein each R may independently be hydrogen or a hydrocarbyl group having 3 to 8, or 4 to 6 carbon atoms, typically 4 carbon atoms. Typically the C3-8 hydrocarbyl phosphite comprises dibutyl phos-phite. The C3-8 hydrocarbyl phosphite may deliver at least 175 ppm, or at least 200 ppm of the total amount of phosphorus delivered by the phosphorus-containing com-pounds. The C3-8 hydrocarbyl phosphite may deliver at least 45 wt %, or 50 wt % to 100 wt %, or 50 wt % to 90 wt % or 60 wt % to 80 wt % of the total amount of phosphorus from the phosphorus-containing compound.
[0052] In one embodiment, the phosphorus-containing compound can be a hydrocarbyl phosphite, or mixtures thereof, i.e., wherein each R may independently be hydrogen or a hydrocarbyl group having 12 to 24, or 14 to 20 carbon atoms, typi-cally 16 to 18 carbon atoms. Typically the C12-22 hydrocarbyl phosphite comprises a C16-18 hydrocarbyl phosphite. Examples of alkyl groups for R3, R4 and R5 include octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonadecyl, eicosyl or mixtures thereof. The C12-22 hydrocarbyl phosphite may be present in the automotive gear oil at about 0.05 wt.% to about 1.0 wt.% of the automotive gear oil, or from about 0.1 wt.% to about 0.5 wt.% of the automotive gear oil.
[0053] In some embodiments, the phosphorous containing compound can include both a C3-8 and a C12 to C24 hydrocarbyl phosphite.
[0054] The lubricant composition optionally further contains an antiwear agent in the form of a hydrocarbyl amine salt of an alkyl(thio)phosphate. The alkyl(thio)phos-phate may also be an amine alkylthiophoshate, wherein the alkylthiophoshate is repre-sented by the formula (R'0)2PSSH, wherein each R' is independently a hydrocarbyl group containing from about 3 to about 30, preferably from about 3 up to about 18, or from about 3 up to about 12, or from up to about 8 carbon atoms. Example R' groups can include isopropyl, isobutyl, n-butyl, sec-butyl, the various amyl, n-hexyl, methylisobutyl carbinyl, heptyl, 2-ethylhexyl, isooctyl, nonyl, behenyl, decyl, do-decyl, and tridecyl groups. Illustrative lower alkylphenyl R' groups include bu-tylphenyl, amylphenyl, heptylphenyl, etc. Examples of mixtures of R' groups in-.. clude: 1-butyl and 1-octyl; 1-pentyl and 2-ethyl-1-hexyl; isobutyl and n-hexyl; iso-butyl and isoamyl; 2-propyl and 2-methyl-4-pentyl; isopropyl and sec-butyl;
and iso-propyl and isooctyl.
[0055] In one embodiment, the alkylthiophoshate of the amine alkylthiophoshate may be reacted with an epoxide or a polyhydric alcohol, such as glycerol. This reac-tion product may be used alone, or further reacted with a phosphorus acid, anhydride, or lower ester. The epoxide is generally an aliphatic epoxide or a styrene oxide. Ex-amples of useful epoxides include ethylene oxide, propylene oxide, butene oxide, octene oxide, dodecene oxide, styrene oxide, etc. Ethylene oxide and propylene oxide are preferred. The polyhydric alcohols are described above. The glycols may be ali-phatic glycols having from 1 to about 12, or from about 2 to about 6, or from 2 or 3 carbon atoms. Glycols include ethylene glycol, propylene glycol, and the like.
The alkylthiophoshate, glycols, epoxides, inorganic phosphorus reagents and methods of reacting the same are described in U.S. Pat. Nos. 3,197,405 and 3,544,465 which are incorporated herein by reference for their disclosure to these.
[0056]
[0057] In one embodiment the hydrocarbyl amine salt of an alkyl(thio)phosphate is the reaction product of a C14 to C18 alkylated phosphoric acid with Primene (produced and sold by Rohm & Haas) which is a mixture of CH to C14 tertiary alkyl primary amines. Other amines which may be used include alkyl alkanol amines, dial-kanolamines, trialkanolamines such as triethanolamines as well as borated amines as described hereinb el ow.
[0058] The amine salt as used as this component may thus comprise a C8 to alkylamine salt of a mono- or di-alkyl phosphate ester, or mixtures thereof.
[0059] The amount of the hydrocarbyl amine salt of an alkylphosphoric acid ester in the lubricant can be 0.3 to 2 weight percent, or 0.4 to 1.9, or 0.5 to 1.8, or 0.7 to 1.7 weight percent. The amounts will be proportionally higher in a concentrate.
The amount of said amine salt may also be an amount to contribute 0.03 to 0.2 weight percent phosphorus to the lubricant composition, or alternatively 0.08 to 0.17, or 0.11 to 0.17 weight percent.
[0060] The automotive gear oil can also include a substantially sulfur-free alkyl phosphate amine salt having at least 30 mole percent of the phosphorus atoms in an alkyl pyrophosphate structure, as opposed to an orthophosphate (or monomeric phos-phate) structure. The percentage of phosphorus atoms in the pyrophosphate structure may be 30 to 100 mole %, or 40 to 90% or 50 to 80% or 55 to 70 % or 55 to 65%.
The remaining amount of the phosphorus atoms may be in an orthophosphate structure or may consist, in part, in unreacted phosphorus acid or other phosphorus species. In one embodiment, up to 60 or up to 50 mole percent of the phosphorus atoms are in mono-or di-alkyl-orthophosphate salt structure.

[0061]
The substantially sulfur-free alkyl phosphate amine salt, as present in the pyrophosphate form (sometimes referred to as the POP structure), may be represented in part by the following formulas (I) and/or (II):

pl (3¨R1 or (I) (II) or variants thereof, such as:

g=-=1 R1¨ o1 1 o1 OH

R23NH R23NH R23NH+

R23NH+ R23NH+
where, each le is independently an alkyl group of 3 to 12 carbon atoms, such as, for example, 2-butyl, 2-pentyl, 3-pentyl, 3-methyl-2-butyl, 2-hexyl, 3-hexyl, cyclohexyl, 4-methyl-2-pentyl, and other such secondary groups and isomers thereof having 6, 7, 8, 9, 10, 11, or 12 carbon atoms. In some embodiments the alkyl group can have a methyl branch at the a-position of the group, an example being the 4-methyl-2-pentyl (also referred to as 4-methylpent-2-y1) group.
[0062]
While the pyrophosphate ester may be isolated, if desired, from the ortho-esters, it is also possible, and may be commercially preferable, to use the reaction mix-ture without separation of the components.

[0063] The structures of formulas (I) and (II) are shown as entirely sulfur-free spe-cies, in that the phosphorus atoms are bonded to oxygen, rather than sulfur atoms.
However, it is possible that a small molar fraction of the 0 atoms could be replaced by S atoms, such as 0 to 5 percent or 0.1 to 4 percent or 0.2 to 3 percent or 0.5 to 2 percent.
[0064] The pyrophosphate phosphate ester or mixture of phosphate esters with be reacted with an amine to form an amine salt. The extent of neutralization in practice, that is, the degree of salting of the ¨OH groups of the phosphorus esters, may be 50%
to 100%, or 80% to 99%, or 90% to 98%, or 93% to 97%, or about 95%, which may be determined or calculated on the basis of the amount of amine charged to the phos-phate ester mixture.
[0065] The amine may be represented by R23N, where each R2 is independently hydrogen or a hydrocarbyl group or an ester-containing group, or an ether-containing group, provided that at least one R2 group is a hydrocarbyl group or an ester-containing group or an ether-containing group (that is, not NH3). Suitable hydrocarbyl amines include primary, secondary or tertiary amines having 1 to 18 carbon atoms, or 3 to 12, or 4 to 10 carbon atoms. Ester containing amines, such as an N-hydrocarbyl-sub stituted y- or 6-amino(thio)ester. The amine, of whatever type, will be reacted to neutralize the acidic group(s) on the phosphorus ester component, which will comprise the pyrophosphate ester as described above as well as any orthophosphate esters that may be present.
[0066] The amount of the substantially sulfur-free alkyl phosphate amine salt in the lubricant composition may be 0.1 to 5 percent by weight. This amount refers to the total amount of the phosphate amine salt or salts, of whatever structure, both ortho-phosphate and pyrophosphate (with the understanding that at least 30 mole percent of .. the phosphorus atoms are in an alkyl pyrophosphate salt structure). The amounts of the phosphate amine salts in the pyrophosphate structure may be readily calculated there-from. Alternative amounts of the alkyl phosphate amine salt may be 0.2 to 3 percent, or 0.2 to 1.2 percent, or 0.5 to 2 percent, or or 0.6 to 1.7 percent, or 0.6 to 1.5 percent, or 0.7 to 1.2 percent by weight. The amount may be suitable to provide phosphorus to the lubricant formulation in an amount of 200 to 3000 parts per million by weight (ppm), or 400 to 2000 ppm, or 600 to 1500 ppm, or 700 to 1100 ppm, or 1100 to ppm.

[0067] The automotive gear oil can also include a material represented by the for-mula R1O__SO R4 0 ______________________________________________ [1 (!)R2 R3 ((!)R5) _ '2 n FORMULA X
¨n wherein It' and R2 are each independently hydrocarbyl groups of 3 to 12 carbon at-5 oms, or 6 to 8 carbon atoms, or are groups represented by or wherein le and R2 together with the adjacent 0 and P atoms form a ring contain-ing 2 to 6 carbon atoms; R3 is hydrogen or a methyl group, R4 is an alkylene group of 2 to 6 carbon atoms, R5 is hydrogen or a hydrocarbyl group of 1 to about 12 carbon 10 atoms, and n is 1 or 2. The material represented by the above formula is typically a neutral compound (or mixture of compounds) as the hydrogen atom shown attached to the phosphorus is not considered to be particularly acidic.
[0068] In certain embodiments the material of Formula X may be represented by the formula (!)R2 2 FORMULA XI
that is, Formula X in which R3 is hydrogen, R4 is an ethylene group, and n is 2. As in the case of Formula X, one or both of the R1 or R2 groups may groups represented by (1R2 In either Formula X or Formula XI, in certain embodiments le and R2 may each inde-pendently be C6 or C8 alkyl groups, or mixtures thereof, such as 2-ethylhexyl groups or 4-methyl-2-pentyl groups or mixtures thereof.
[0069] The amount of any the phosphorous ester product described above used in the automotive gear oil may be an amount sufficient to provide 0.01 to 0.3 or to 0.1 weight percent phosphorus to the composition or, in other embodiments, 0.02 to 0.07 weight percent or 0.025 to 0.05 weight percent. The actual amount of the product which corresponds to these amounts of phosphorus will, of course, depend upon its phosphorus content. Suitable amounts of the ester product in the automotive gear oil may be 0.01 to 1.0 weight percent, or 0.02 to 0.5 weight percent, or 0.03 to 0.30 weight percent, or even 0.05 to 0.25 weight percent.
[0070] While each of the phosphorus containing compounds described above may be present in the automotive gear oil on its own, the automotive gear oil may also include a mixture of two or more. In some embodiments, the phosphorous containing compound can include a C3-8 hydrocarbyl phosphite and a phosphite ester product. In some embodiments, the phosphorous containing compound can include each of a C3-.. hydrocarbyl phosphite, a C12 to C24 hydrocarbyl phosphite, and a phosphite ester prod-uct. In either event, the phosphorus containing compound should be present in an amount to deliver 100 to 1500 ppm of phosphorus to the automotive gear oil. In some embodiments, the at least one phosphorus containing compound can be present in an amount to deliver 250 to 1250 ppm of phosphorus, or from 500 to 1000 ppm phospho-rus to the automotive gear oil.
[0071] Another component of the automotive gear oil can be a metal deactivator.
Examples of such materials include 2,5-dimercapto-1,3,4-thiadiazole and/or deriva-tives thereof. Such materials are described in European Patent Publication 0761805, incorporated herein by reference. Further examples of the metal deactivator include the thiadiazole compounds, such as those described in US9,816,044, and represented by the formula:
N-----N
N-N
SH SR
R = t-nonyl, n-octyl or n-dodecyl or t-dodecyl [0072]
The metal deactivators that are useful herein reduce the corrosion of met-als, such as copper. Metal deactivators are also referred to as metal passivators. These metal deactivators are typically nitrogen and/or sulfur containing heterocyclic com-pounds, such as dimercaptothiadiazoles, triazoles, aminomercaptothiadiazoles, imid-azoles, thiazoles, tetrazoles, hydroxyquinolines, oxazolines, imidazolines, thio-phenes, indoles, indazoles, quinolines, benzoxazines, dithiols, oxazoles, oxatriazoles, pyridines, piperazines, triazines, and derivatives of any one or more thereof.
The metal deactivator preferably comprises at least one triazole, which may be substituted or unsubstituted. Examples of suitable compounds are benzotriazole, alkyl-substi-tuted benzotriazole (e.g., tolyltriazole, ethylbenzotriazole, hexylbenzotriazole, oc-tylbenzotriazole, etc.), aryl-substituted benzotriazole (e.g., phenol benzotriazol es, etc.), and alkylaryl- or arylalkyl-substituted benzotriazole and substituted benzotria-zoles where the substituent may be hydroxy, alkoxy, halo (especially chloro), nitro, carboxy and carboxyalkoxy. Preferably, the triazole is a benzotriazole or an alkylben-zotriazole in which the alkyl group contains 1 to about 20 carbon atoms, preferably 1 to about 8 carbon atoms. Benzotriazole and tolyltriazole are useful.
[0073] In one embodiment, the metal deactivator is the reaction product of a dis-persant with a dimercaptothiadiazole. The dispersants may be generally characterized as the reaction products of carboxylic acids with amines and/or alcohols.
These reac-tion products are commonly used in the lubricant arts as dispersants and are some-times referred to generically as dispersants despite the fact that they may have other uses in addition to or instead of that as dispersants. The carboxylic dispersants in-clude succinimide dispersants, ester type dispersants and the like.
Succinimide dis-persants are generally the reaction of a polyamine with an alkenyl succinic anhydride or acid. Ester type dispersants are the reaction product of an alkenyl succinic anhy-dride or acid with a polyol compound. The reaction product may then be further treated with an amine such as a polyamine. Examples of useful dispersants are dis-closed in U.S. Pat. Nos. 3,219,666 and 4,234,435, incorporated herein by reference.
Useful dispersants also include the ashless dispersants discussed below.
Generally the reaction occurs between the dispersant and the dimercaptothiadiazole by mixing the two and heating to a temperature above about 100 C. U.S. Pat. Nos.
4,140,643 and 4,136,043 describe compounds made by the reaction of such dispersants with a dimercaptothiadiazole. These patents are incorporated herein by reference for their disclosure of dispersants, dimercaptothiadiazole, the method for reacting the two and the products obtained from such reaction.
[0074] In one embodiment, the metal deactivator is the reaction product of a phe-nol with an aldehyde and a dimercaptothiadiazole. The phenol is preferably an alkyl phenol wherein the alkyl group contains at least about 6, preferably from 6 to about 24, more preferably about 6, or about 7, to about 12 carbon atoms. The aldehyde is preferably an aldehyde containing from 1 to about 7 carbon atoms or an aldehyde synthon, such as formaldehyde. Preferably, the aldehyde is formaldehyde or para-formaldehyde. The aldehyde, phenol and dimercaptothiadiazole are typically reacted by mixing them at a temperature up to about 150 C, preferably about 50 C to about 130 C, in molar ratios of about 0.5 to about 2 moles of phenol and about 0.5 to about 2 moles of aldehyde per mole of dimercaptothiadiazole. Preferably, the three reagents are reacted in equal molar amounts.
[0075] In one embodiment, the metal deactivator is a bis(hydrocarbyldithio)thia-diazole. Preferably each hydrocarbyl group is independently an alkyl, aryl or aralkyl group, having from 6 to about 24 carbon atoms. Each hydrocarbyl can be inde-pendently t-octyl, nonyl, decyl, dodecyl or ethylhexyl. The metal deactivator can be bis-2,5-tert-octyl-dithio-1,3,4-thiadiazole or a mixture thereof with 2-tert-octylthio-5-mercapto-1,3,4-thiadiazole. These materials are available commercially under the trade name of Amoco 150, which is available from Amoco Chemical Company. These dithiothiadiazole compounds are disclosed as Component (d) in PCT Publication WO

88/03551, incorporated by reference for its disclosure of dithiothiadiazole com-pounds. In the preferred embodiments the metal deactivator is a dimercaptothiadia-zole derivative. Example D-1 is a specific example.
[0076] Example D-1 [0077] 2,5-dimercapto-1,3,4-thiadiazole oxidatively coupled with t-nonyl mer-captan; 100% chemical, 36% S, 6.4% N.
[0078] When used, the amount of metal deactivator in the automotive gear oil is generally in the range of about 0.01 to about 0.5 wt.% by weight of the automotive gear oil. In some embodiments, the amount of the metal deactivator is in the range of about 0.02 to about 0.42 wt.% or about 0.03 to about 0.33 wt,% or about 0.04 to about 0.24 wt.% by weight of the automotive gear oil.
[0079] Another material which may optionally be present is a viscosity modifier.
Viscosity modifiers (VM) and dispersant viscosity modifiers (DVM) are well known.
Examples of VMs and DVMs may include polymethacrylates, polyacrylates, polyole-fins, hydrogenated vinyl aromatic-diene copolymers (e.g., styrene-butadiene, styrene-isoprene), styrene-maleic ester copolymers, and similar polymeric substances includ-ing homopolymers, copolymers, and graft copolymers, including polymers having lin-ear, branched, or star-like structures. The DVM may comprise a nitrogen-containing methacrylate polymer or nitrogen-containing olefin polymer, for example, a nitrogen-containing methacrylate polymer derived from methyl methacrylate and dimethyla-minopropyl amine. The DVM may alternatively comprise a copolymer with units de-rived from an a-olefin and units derived from a carboxylic acid or anhydride, such as maleic anhydride, in part esterified with a branched primary alcohol and in part reacted with an amine-containing compound.
[0080] Examples of commercially available VMs, DVMs and their chemical types may include the following: polyisobutylenes (such as IndopolTM from BP Amoco or ParapolTM from ExxonMobil); olefin copolymers (such as Lubrizol 7060, 7065, and 7067, and Lucant HC-2000, HC-1100, and HC-600 from Lubrizol); hydrogenated sty-rene-diene copolymers (such as ShellvisTM 40 and 50, from Shell and LZ 7308, and 7318 from Lubrizol); styrene/maleate copolymers, which are dispersant copolymers (such as LZ 3702 and 3715 from Lubrizol); polymethacrylates, some of which have dispersant properties (such as those in the ViscoplexTM series from RohMax, the HitecTM series of viscosity index improvers from Afton, and LZ 7702, LZ
7727, LZ
7725 and LZ 7720C from Lubrizol); olefin-graft-polymethacrylate polymers (such as ViscoplexTM 2-500 and 2-600 from RohMax); and hydrogenated polyisoprene star pol-ymers (such as ShellvisTM 200 and 260, from Shell). Viscosity modifiers that may be 5 used are described in U.S. patents 5,157,088, 5,256,752 and 5,395,539.
The VMs and/or DVMs may be used in the functional fluid at a concentration of up to 50% or to 20% by weight, depending on the application. Concentrations of 1 to 20%, or 1 to 12%, or 3 to 10%, or alternatively 20 to 40%, or 20 to 30% by weight may be used.
[0081] Other optional materials may include antioxidants, e.g., aromatic amine an-10 .. tioxidants, hindered phenolic antioxidants including ester-containing hindered phe-nolic antioxidants, and sulfurized olefin antioxidants. In an embodiment, the automo-tive gear oil may contain a mixture of at least two anti-oxidants. These antioxidants may optionally be present in amounts of 0.01 to 5, or 0.15 to 4.5 or 0.2 to 4, or 0.2 to 2 percent by weight.
15 [0082] In one embodiment, the automotive gear oil can include an aryl amine an-tioxidant. The aryl amine antioxidant may be a phenyl-a-naphthylamine (PANA) or a hydrocarbyl substituted diphenylamine, or mixtures thereof. The hydrocarbyl sub-stituted diphenylamine may include mono- or di- C4 to C16-, or C6 to C12-, or alkyl diphenylamine. For example the hydrocarbyl substituted diphenylamine may 20 be octyl diphenylamine, or di-octyl diphenylamine, dinonyl diphenylamine, typically dinonyl diphenylamine.
[0083] When present the aryl amine antioxidant may be present at 0.2 wt % to 1.2 wt %, or 0.3 wt % to 1.0 wt %, or 0.4 wt % to 0.9 wt % or 0.5 wt % to 0.8 wt %, of the automotive gear oil.
[0084] The hindered phenol antioxidant often contains a secondary butyl and/or a tertiary butyl group as a sterically hindering group. The phenol group is often further substituted with a hydrocarbyl group and/or a bridging group linking to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propy1-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol, or 4-dodecy1-2,6-di-tert-butylphenol. In one embodiment the hindered phenol antioxidant may be an ester and may include, e.g., IrganoxTM L-135 from Ciba, or butyl 3-(3,5-di-tert-buty1-4-hydroxyphenyl)propanoate.
[0085] If present, the hindered phenol antioxidant may be present at 0.1 wt % to 1 wt %, or 0.2 wt % to 0.9 wt % or 0.1 wt % to 0.4 wt %, or 0.4 wt % to 1.0 wt %, of the automotive gear oil.
[0086] Antioxidants also include sulfurized olefins such as mono-, or disulfides or mixtures thereof. These materials generally have sulfide linkages having 1 to 10 sulfur atoms, for instance, 1 to 4, or 1 or 2. Materials which can be sulfurized to employ as sulfurized antioxidants in the automotive gear oil can include oils, fatty .. acids and esters, olefins and polyolefins made thereof, terpenes, or Diels-Alder ad-ducts. Details of methods of preparing some such sulfurized materials can be found in U.S. Pat. Nos. 3,471,404 and 4,191,659.
[0087] The automotive gear oil may also include a calcium-containing detergent.
While the calcium-containing detergent is preferably not present, it can be included .. in an amount to deliver up to 150 ppm or 180 ppm of calcium to the composition, or from 30 ppm to 180 ppm, or 30 ppm to 150 ppm of calcium, or from 60 ppm to 180 ppm, or even from 60 ppm to 150 ppm of calcium.
[0088] In some embodiments, the calcium-containing detergent may be present at 90 ppm or less, or from 1 to 90 ppm, or even from 5 to 80 ppm or 10 to 75 ppm.
[0089] The calcium-containing detergent may be an overbased detergent, a non-overbased detergent, or mixtures thereof. Typically the detergent is overbased.
[0090] The preparation of the calcium-containing detergent is known in the art.
Patents describing the preparation of overbased calcium-containing detergents in-clude U.S. patents 2,501,731; 2,616,905; 2,616,911; 2,616,925; 2,777,874;
3,256,186; 3,384,585; 3,365,396; 3,320,162; 3,318,809; 3,488,284; and 3,629,109.
[0091] The calcium-containing detergent may be a non-overbased detergent (may also be referred to as a neutral detergent). The TBN of a non-overbased may be to less than 200, or 30 to 100, or 35 to 50 mg KOH/g. The TBN of a non-overbased calcium-containing detergent may also be 20 to 175, or 30 to 100 mg KOH/g.
When .. a non-overbased calcium-containing detergent is prepared from a strong acid such as a hydrocarbyl-substituted sulphonic acid, the TBN may be lower (for example 0 to 50 mg KOH/g, or 10 to 20 mg KOH/g).

[0092] As used herein the TBN values quoted and associated range of TBN
is on "an as is basis," i.e., containing conventional amounts of diluent oil.
Conventional amounts of diluent oil typically range from 30 wt % to 60 wt % (often 40 wt % to 55 wt %) of the detergent component.
[0093] The calcium-containing detergent may be an overbased detergent, having, for example, a TBN of greater than 200 mg KOH/g (typically 250 to 600, or 300 to 500 mg KOH/g).
[0094] The overbased calcium-containing detergent may be formed by the reaction of a basic calcium compound and an acidic detergent substrate. The acidic detergent substrate may include an alkyl aromatic sulphonic acid (such as, alkyl naphthalene sul-phonic acid, alkyl toluene sulphonic acid or alkyl benzene sulphonic acid), an alkyl sali-cylic acid, or mixtures thereof.
[0095] The basic calcium compound is used to supply basicity to the detergent.
The basic calcium compound is a compound of a hydroxide or oxide of the calcium.
[0096] The oxides and/or hydroxides may be used alone or in combination.
The oxides or hydroxides may be hydrated or dehydrated, although hydrated is typical.
In one embodiment the basic calcium compound may be calcium hydroxide, which may be used alone or mixtures thereof with other metal basic compounds.
Calcium hydroxide is often referred to as lime. In one embodiment the calcium basic com-pound may be calcium oxide which may be used alone or mixtures thereof with other metal basic compounds.
[0097] In one embodiment the calcium-containing detergent may be a sulphonate, or mixtures thereof. The sulphonate may be prepared from a mono- or di- hydro-carbyl-sub stituted benzene (or naphthalene, indenyl, indanyl, or bicyclopentadienyl) sulphonic acid, wherein the hydrocarbyl group may contain 6 to 40, or 8 to 35 or 9 to carbon atoms.
[0098] The hydrocarbyl group may be derived from polypropylene or a linear or branched alkyl group containing at least 10 carbon atoms. Examples of a suitable alkyl group include branched and/or linear decyl, undecyl, dodecyl, tridecyl, 30 tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, octadecenyl, nonodecyl, eicosyl, un-eicosyl, do-eicosyl, tri-eicosyl, tetra-eicosyl, penta-eicosyl, hexa-eicosyl or mixtures thereof.

[0099] In one embodiment the hydrocarbyl-substituted sulphonic acid may in-clude polypropene benzenesulphonic acid and/or C16-C24 alkyl benzenesulphonic acid, or mixtures thereof.
[0100] In one embodiment a calcium sulphonate detergent may be a predominantly linear alkylbenzene sulphonate detergent having a metal ratio of at least 8 as is described in paragraphs [0026] to [0037] of US Patent Application 2005065045 (and granted as US
7,407,919). In some embodiments the linear alkyl group may be attached to the benzene ring anywhere along the linear chain of the alkyl group, but often in the 2, 3 or 4 position of the linear chain, and in some instances predominantly in the 2 position.
[0101] When neutral or slightly basic, a calcium sulphonate detergent may have TBN of less than 100, or less than 75, typically 20 to 50 mg KOH/g, or 0 to 20 mg KOH/g.
[0102] When overbased, a calcium sulphonate detergent may have a TBN
greater than 200, or 300 to 550, or 350 to 450 mg KOH/g.
[0103] Phenate detergents are typically derived from p-hydrocarbyl phenols or, generally, alkylpheols. Alkylphenols of this type may be coupled with sulfur and overbased, coupled with aldehyde and overbased, or carboxylated to form salicylate detergents. Suitable alkylsalicylates include those alkylated with oligomers of pro-pylene, oligomers of butene, especially tetramers and pentamers of n-butenes, as well as those alkylated with alpha-olefins, isomerized alpha-olefins, and polyolefins like polyisobutylene. In one embodiment, the automotive gear oil comprises less than 0.2 wt %, or less than 0.1 wt %, or even less than 0.05 wt % of a salicylate de-tergent derived from para-dodecylphenol (PDDP). In one embodiment, the automo-tive gear oil comprises a salicylate detergent that is not derived from PDDP.
In one embodiment, the automotive gear oil can comprise a salicylate detergent prepared from PDDP, such detergent contains less than 1.0 weight percent unreacted PDDP, or less than 0.5 weight percent unreacted PDDP, or is substantially free of PDDP.
[0104] The detergent may be borated or non-borated.
[0105] Chemical structures for sulphonates, and salicylate detergents are known to a person skilled in the art. The standard textbook entitled "Chemistry and Technology of Lubricants", Third Edition, Edited by R. M. Mortier and S. T. Orszulik, Copyright 2010, pages 220 to 223 under the sub-heading 7.2.6 provide general disclosures of said detergents and their structures.
[0106] In one embodiment the calcium-containing detergent may be an overbased calcium sulphonate, an overbased calcium salicylate, or mixtures thereof.
Typically the detergent may be an overbased calcium sulphonate.
[0107] In one embodiment the calcium-containing detergent may be in a mixture with a zinc-, barium-, sodium-, or magnesium- containing detergent. The zinc-, bar-ium-, sodium-, or magnesium- containing detergent is also well known in the art and described in the same references describing a calcium-containing detergent.
The .. TBN and metal ratios may however, differ slightly. The zinc-, barium-, sodium-, or magnesium- containing detergent may be a phenate, a sulphur-containing phenate, sulphonate, salixarate or salicylate. Typically a zinc-, barium-, sodium-, or magne-sium- containing detergent may be a magnesium phenate, a magnesium sulphur-con-taining phenate, or a magnesium sulphonate.
[0108] A more detailed description of the expressions "metal ratio", TBN
and "soap content" are known to a person skilled in the art and explained in standard textbooks, such as, for example, "Chemistry and Technology of Lubricants", Third Edition, Edited by R. M. Mortier and S. T. Orszulik, Copyright 2010, pages 219 to 220 under the sub-heading 7.2.5. Detergent Classification.
[0109] The automotive gear may also include a friction modifier. In one embod-iment the friction modifier may be, for example, long chain fatty acid derivatives of amines, long chain fatty esters, or derivatives of a long chain fatty epoxides; fatty imidazolines; amine salts of alkylphosphoric acids; fatty alkyl tartrates;
fatty alkyl tartrimides; fatty alkyl tartramides; fatty glycolates; and fatty glycolamides, or com-binations thereof. The friction modifier may be present at 0 wt % to 6 or to 5 wt %, or 0.01 wt % to 4 wt %, or 0.05 wt % to 2 wt %, or 0.1 wt % to 2 wt % of the lubricating composition. The amount of friction modifier, if present, also may be 0.05 to 5 percent by weight, or 0.1 to 2 percent, or 0.1 to 1.5 percent by weight, or 0.15 to 1 percent, or 0.15 to 0.6 percent.
[0110] As used herein the term "fatty alkyl" or "fatty" in relation to friction mod-ifiers means a carbon chain having 10 to 22 carbon atoms, typically a straight carbon chain. Alternatively, the fatty alkyl may be a mono branched alkyl group, with branching typically at the 3-position. Examples of mono branched alkyl groups in-clude 2-ethylhexyl, 2-propylheptyl or 2-octyldodecyl.
[0111] Examples of suitable friction modifiers include long chain fatty acid de-rivatives of amines, fatty esters, or fatty epoxides; fatty imidazolines such as conden-5 sation products of carboxylic acids and polyalkylene-polyamines; amine salts of al-kylphosphoric acids; fatty alkyl tartrates; fatty alkyl tartrimides; fatty alkyl tar-tramides; fatty phosphonates; fatty phosphites; borated phospholipids, borated fatty epoxides; glycerol esters; borated glycerol esters; fatty amines; alkoxylated fatty amines; borated alkoxylated fatty amines; hydroxyl and polyhydroxy fatty amines 10 including tertiary hydroxy fatty amines; hydroxy alkyl amides; metal salts of fatty acids; metal salts of alkyl salicylates; fatty oxazolines; fatty ethoxylated alcohols;
condensation products of carboxylic acids and polyalkylene polyamines; or reaction products from fatty carboxylic acids with guanidine, aminoguanidine, urea, or thiou-rea and salts thereof.
15 [0112] Friction modifiers may also encompass materials such as sulphurised fatty compounds and olefins, molybdenum dialkyldithiophosphates, molybdenum dithio-carbamates, sunflower oil or soybean oil monoester of a polyol and an aliphatic car-boxylic acid.
[0113] In one embodiment the friction modifier may be a long chain fatty acid 20 ester. In another embodiment the long chain fatty acid ester may be a mono-ester and in another embodiment the long chain fatty acid ester may be a triglyceride [0114] In an embodiment, the automotive gear oil is substantially free of friction modifiers. In some embodiments, the automotive gear oil is completely free of fric-tion modifiers.
25 [0115] The automotive gear oil may have a kinematic viscosity at 100 C of from 8 cSt to 24 cSt, or for example, from 9 cSt to 21 cSt, or even 10 cSt to 20 cSt.
[0116] One aspect is therefore a method of lubricating an automotive gear by sup-plying to the automotive gear the automotive gear oil as disclosed herein, and oper-ating the automotive gear. The automotive gear oil will be suitable for lubricating automotive gears, including gears in transmissions, such as manual or dual clutch transmission, gears on axles, and gears on differentials.

[0117] The automotive gear oil may, in particular, be employed in a manual gear-box of a manual transmission, which may be unsynchronized, or may contain a syn-chronizer mechanism. The gearbox may be self-contained, or may additionally con-tain any of a transfer gearbox, planetary gear system, differential, limited slip differ-ential or torque vectoring device, which may be lubricated by a manual transmission fluid.
[0118] The automotive gear oil may be used in planetary hub reduction axles, mechanical steering and transfer gear boxes in utility vehicles, synchromesh gear boxes, power take-off gears, limited slip axles, and planetary hub reduction gear boxes.
[0119] In an embodiment, the automotive gear oil can be employed as a single lub-ricant to lubricate the entire driveline system of an automobile having a manual trans-mission. That is, in an embodiment, the automotive gear oil may be employed as a "total driveline lubricant," suitable to lubricate all the gears in the automobile, in-cluding in the transmission and in the axles and differentials.
[0120] As used herein, the term "condensation product" is intended to encompass esters, amides, imides and other such materials that may be prepared by a condensation reaction of an acid or a reactive equivalent of an acid (e.g., an acid halide, anhydride, or ester) with an alcohol or amine, irrespective of whether a condensation reaction is actually performed to lead directly to the product. Thus, for example, a particular ester may be prepared by a transesterification reaction rather than directly by a condensation reaction. The resulting product is still considered a condensation product.
[0121] The amount of each chemical component described is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial ma-terial, that is, on an active chemical basis, unless otherwise indicated.
However, unless otherwise indicated, each chemical or composition referred to herein should be inter-preted as being a commercial grade material which may contain the isomers, by-prod-ucts, derivatives, and other such materials which are normally understood to be present in the commercial grade.
[0122] As used herein, the term "hydrocarbyl substituent" or "hydrocarbyl group"
is used in its ordinary sense, which is well-known to those skilled in the art. Specifi-cally, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydro-carbyl groups include:
[0123] hydrocarbon substituents, that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g., cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-, and alicyclic-substituted aromatic substituents, as well as cyclic substituents wherein the ring is com-pleted through another portion of the molecule (e.g., two substituents together form a ring);
[0124] substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predomi-nantly hydrocarbon nature of the substituent (e.g., halo (especially chloro and fluoro), hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and sulfoxy);
[0125] hetero substituents, that is, substituents which, while having a predomi-nantly hydrocarbon character, in the context of this invention, contain other than car-bon in a ring or chain otherwise composed of carbon atoms and encompass substituents as pyridyl, furyl, thienyl and imidazolyl. Heteroatoms include sulfur, oxygen, and ni-trogen. In general, no more than two, or no more than one, non-hydrocarbon substitu-ent will be present for every ten carbon atoms in the hydrocarbyl group;
alternatively, there may be no non-hydrocarbon substituents in the hydrocarbyl group.
[0126] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that are initially added. For instance, metal ions (of, e.g., a detergent) can migrate to other acidic or anionic sites of other molecules. The products formed thereby, including the products formed upon employing the composition of the present invention in its intended use, may not be susceptible of easy description.
Nevertheless, all such modifications and reaction products are included within the scope of the pre-sent invention; the present invention encompasses the composition prepared by admix-ing the components described above.
[0127] As used herein, the term "about" means that a value of a given quantity is within 20% of the stated value. In other embodiments, the value is within 15% of the stated value. In other embodiments, the value is within 10% of the stated value. In other embodiments, the value is within 5% of the stated value. In other embodiments, the value is within 2.5% of the stated value. In other embodiments, the value is within 1% of the stated value.
[0128] Additionally, as used herein, the term "substantially" means that a value of a given quantity is within 10% of the stated value. In other embodiments, the value is within 5% of the stated value. In other embodiments, the value is within 2.5% of the stated value. In other embodiments, the value is within 1% of the stated value.
[0129] The invention herein is useful for lubricating an automotive gear, which may be better understood with reference to the following examples.
[0130] EXAMPLES
[0131] Automotive gear oils were prepared and tested for dynamic friction, 1,i-V
gradient, and thermal stability (to test cleanliness). The fluids can be seen in table 1 below.
Baseline Baseline Experimental Fluid 1 Fluid 2 Fluid 1 4 cSt Oil of Lubricating 70.49 71.99 70.99 Viscosity Viscosity Modifier 21 21 21 Extreme Pressure Agent 3.80 3.80 3.80 Corrosion Inhibitor 0.10 0.10 0.10 Berated Dispersant' 0.43 0.31 0.31 Non-Borated Dispersant 0.71 0.18 0.18 Antiwear Agent2 1.32 1.00 1.00 Antifo am 0.01 0.01 0.01 Friction Modifier 0.35 0.3 0.3 Boron Containing Com-1.0 pound3 Total 100 100 100 'Delivers 133, 95 and 95 ppm Boron to the fluids, respectively 'Delivers 1115, 845 and 845 ppm Phosphorus to the fluids, respectively 'Delivers 270ppm Boron to the fluid [0132] The formulations were tested in a synchronizer test rig in a "durability test."
This is a screening test that is customarily used to evaluate friction and durability charac-teristic of a clutch synchronizer. The test rig typically does not simulate a ful I engagement of the synchronizer components, but does measure the friction between the synchronizer ring and the gear cone. The rig comprises a test rig bath in which the components are assembled.

[0133] An Automax rig comprises a test rig bath in which the components are as-sembled. The synchronizer is attached to the test rig key on one side of the chamber and the cone assembled onto a test rig jig on the other side. The test conditions used are shown in the Table below. The fluids are maintained at 80 C. with the synchronizer typically rotating at 1000 rpm. In each test, there is an initial break-in phase of 100 cycles of en-gagement. Thereafter, multiple cycles of engagement consist of 0.2 seconds of contact followed by 5 seconds of separation, running at 1000 r.p.m. at 80 C. and a load during contact of 981 N (100 kg).
Oil Temperature ( C.) 80 Speed (rpm) 1000 Load (kg) 100 (N) 980.6 On Time (sec) 0,2 Off Time (sec) 5.0 Inertia (kg cm sec2) 2.67 Calculated Torque (NM) 41 [0134] The key features of the synchronizer used in this experiment are summarized in the table below. All other parts are original equipment manufacturer production parts used in standard vehicles:
Phenolic Resin Synchronizer Gear Cone Angle (degrees) 7,0 Effective radius (mm) 62 Composition Phenolic Resin [0135] The data from the test provides several key parameters that allow a comparison of the friction performance of the candidates. Comparisons of the relative durability and shift quality of the different candidates are made based upon a number of parameters in-cluding dynamic friction level assessed by the friction value during durability testing, fric-tion durability assessed by the stability, and trends in average friction values during the durability phase.
[0136] Shift quality is assessed by examining the performance test profiles which show the variation of friction with rotational speed. It is desirable to have a flat frictional . , = PCT/US 2019/012 031 -24.09.201.9 Case No. 4573 30 101351 The data from the teat provides several key parameters that allow a comparison of the fiction perfomiance of the candidates, Comparisons of the relative durability and shift quality of the different candidates are made based upon a number of parameters in -eluding dynamic fiction level assessed by the fiction value during durability testing, frit:-tion durability assessed by the stability, and trends in average friction values during the durability phase. ..
[01361 Shift quality is assessed by examining the performance test profiles which show the variation of friction with rotational speed. it is desirable to have a fat frictional profile, with 3 level or slight decrease in friction at low speed providing improved syn-cbronizer engagement and improved shift quality.
[01371 The dynamic coefficient of friction may be presented as a function of cycle number. A quantitative representation of the performance may be obtained by calculating the number of cycles to stability. Ideally, a fluid should show stable friction throughout the duration of the test. Some fluids may vary in friction at the start of the test, before stabilizing to a final value after a number of cycles. Other fluids may not stabilize at all and the friction may be still increasing or decreasing after 10,000 cycles.
One method of assessing dynamic fiction is to evaluate the mean and standard deviation of the friction values &nine the 10,000 cycle teat.
Dynamic Friction õ
Baseline = --1'.== Baseline 1 Experimental =:, Fluid 1 Fluid 2 1 Finial .
= - ==,. ¨
Cycle pV-AVG .. . ly-AvG r pv-ANG , -1,-- ,-1 t 0.116 ii 0112 ' 0 113 ' f--Too- 0.119 ii 0.116 I 0.115 i.I.
500 0.12 0.114 i 0.115 ., t ........ f i ....
1000 j 0118 i 0 0116 . ¨
108 : -+:
= 2000 I. 0.114 . ; ..... 0.105 _4 0.116 ' _ '= ..................... 3000 :1. 0.113 . . Ø104 , 0.115 ....................... 4000 i 0112 - 0.103 0115 - ¨ . .
5000 1 0.112 0.102 !
: 0.115 :. ....
= 6000 1! . _0.111 0.102 0.114... .. ..... :
. 7000 =õ.,,. 0111 ' 0.102 _____ = = 0.114 8000 ' 0,111 9001: p,i11 . .
, 0.102 _ . _ . _0.114 .
0.102 , . .. 0.113 = =
-' 10000 0 11 4 0.102 0 113 :--- , ..
AMENDED SHEET
Date Recue/Date Received 2020-07-03 õ õ ,... ..
.

, . . PCT/US 2019/012 031 -24.09.2019 , Case No. 4573 31 [0138] In order to assess the shift-quality of an individual engagement it is necessary to evaluate the friction versus speed relationship. One parameter that is useful is to assess the curvature of the speed-friction relationship. In order to do this a chord is drawn between the p values between 50 to 1000 rpm. The area of the difference between the actual !Id and the chord gives a value that we will refer to as the curvature of the line. A
large negative curvature value represents a poor result and a value that is close to zero or positive, indi-cates a better performance.
, .. ..... -.. i pre lest Friction , ' Post Test Friction Baseline Baseline I Experimental I
: I Baseline :3 Baseline Experimental(,1 ; .......... Fittid 1 Fluid 2 i Fluid 1 = I Fluid 1 ii, 'Fluid 2 õFluid 1 .1 r-----: 1--I Initial i : Final Final Final Bridal Meas- Initial Meas- i Was- 1 I
flrpm Measure- 1 uremen, rpm Meas- Meas.
urement 1 i = L ment .. I ... - $ 1 . urement . ,.urement ...,.uremeint t I
= r t- = i 50 0.119 I 0.112 t 0.116 __ 11 50. ' i_ 0.131 ' ' 0.125 , 0.22 75I .
.'= 75 0.121 - A 0.114 i - DITir ' ' 0.129 ' :
0.122 .. : .. 0.121 100 !. :
..Q.123 _ 4 0.115 ..1 Ø118 . . ......
1,00 I 0.126 .0,118 0i23 .'3 _. 0115s i . 0.118 125 = 0.126 1 0.1.16 ' 0.123 -_13.123 . .
i ---/-' 200 0121 ,. 0114 1 0.117 1 200 . 0.121 I 0 0 .112 .
.122 . ., ......... 300 i Ø12 ..... ',: 0.113 .. i .. 0 117 : I 300 0.119 I 0.11 ' 0,121 - =
..... ..,,: I. .., ,....... ' .., 500 1 0118 "4' - 0.111 1 " ails i 500 0.116 ....1 0.107 0.119 ,-,.........._ . ..f. - I
: 750 .'1, 0.117 0.111 0.114 L 750 ..
0.11.3. ...1. 0.105 . 0.116 .
...4, .....: -. , .... 1000 0.117 1 0.112 0113 = L_Ipiti2:21.2._' j_91o3 : - '''' 6414 , .. 6 . - ..., ., -.
101391 As can be seen in the tables, Experimental Fluid 1 shows a stabilized friction over the test cycles.
101401 The wear performance provided by the lubricant was also be tested. Wear may be determined from the test rig profile described above, by measuring mg weight loss from the synchronizer ring at the end of the testing. The wear readings for the fluids are provided belowõ
.... ...... ..........::
i .... .
- Baseline 1 Basethre Experinientii .
1 Fluid 1 Fluid 2 Fluid 1 ..................................... J.''' ... WO I . Amid OW
' Wear read- 1 879 1 41.4 36.4 , ing . .
(01411 500 ml samples of the fluids were tested for thermal stability by the JIS
IC2514-1 Indiana Stirring Oxidation Test at 150 C, heated for 96 hours at 1,300 rpm.
The results are shown in the table below. The laquer rating scale is as follows: 0 - no deposit, I = light deposit, 2 - medium deposit and 3 = heavy deposit.

AMENDED SHEET
Date Recue/Date Received 2020-07-03 ... . , PCT/US 2019/012 031 - 24.09.2019 Case No. 4573 32 Baseline I¨Baseline Expe.rimental Fluid I ' Fluid 2 Fluid 1 Heating Time/hours Lacquer Rating ___________________ 0 0 48 ________________________________________ 1 ........ 1 96 3 .. I .. 3 T

________________________________ ¨ -[0142] Each of the documents referred to above is incorporated herein by reference, including any prior applications, whether or not specifically listed above, from which priority is claimed. The mention of any document is not an admission that such docu-ment qualifies as prior art or constitutes the general knowledge of the skilled person in any jurisdiction. Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction con-ditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word "about." It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Sim-ilarly, the ranges and amounts for each element of the invention can be used together with ranges or amounts for any of the other elements.
(01431 As used herein, the transitional term "comprising," which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and 5 does not exclude additional, un-recited elements or method steps. However, in each recitation of "comprising" herein, it is intended that the term also encompass, as alter-native embodiments, the phrases "consisting essentially of" and "consisting of," where "consisting of' excludes any element or step not specified and "consisting essentially of' permits the inclusion of additional un-recited elements or steps that do not materi-ally affect the essential or basic and novel characteristics of the composition or method under consideration.
101441 While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will he apparent to those skilled in this art that various changes and modifications can be made therein without de-parting from the scope of the subject invention. In this regard, the scope of the in-vention is to be limited only by the following AMENDED SHEET
Date Recue/Date Received 2020-07-03

Claims

PCT/US 2019/012 031 - 24.09.2019 =
Case No. 4573 1 What is claimed is:

1. An automotive gear oil for lubricating an automotive gear comprising a. an oil of lubricating viscosity b. 0.025 to 0.9 wt.% of a succinimide dispersant, and c. about 0.2 to 2.0 wt % of at least one boron-containing compound in an amount sufficient to provide from about 75ppm to about 500 ppm of boron to the automotive gear oil, wherein the at least one boron-containing compound is a borate ester of formula I.
ROõ
RO
wherein each R, independently, is a C3 tO Ci2 alkyl, and d. 0.01 =wt to 0.5 wL % of a dimercaptothiadiazole or derivative thereof.

2. The automotive gear oil of claim 1 wherein the automotive gear oil has a kinematic viscosity at 1.00 C of from S cSt to 24 cSt.

3. The automotive gear oil of claim of any previous claim further compris-ing at least one phosphorous containing compound present in an amount to deliver 100 to 1500 ppm of phosphorus to the automotive gear oil:

4a The automotive gear oil of claim 3, where the phosphorous containing compound comprises at least one of: (1) a Ca.s hydrocarbyl phosphite, (2) a phosphite ester composition that comprises the reaction product of a monomeric phosphorous acid or an ester thereof with at least two al-kylene diols, (3) a phosphate ester amine salt, (4) a pyrophosphate amine slit, or (5) mixtures of any of (1) to (4).

5. The automotive gear oil of any previous claim further comprising a vis-cosity modifier.

6. The automotive gear oil of claim of any previous claim further compris-ing a friction modifier.

7. The automotive gear oil of claim of any previous claim further compris-ing a detergent.

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Date Recue/Date Received 2020-07-03 PCT/US 2019/012 031 - 24.09.2019 Case No. 4573 2

8. A method of lubricating an automotive gear comprising supplying to the automotive gear a composition of any previous claim, and operating the automotive gear,

9. The method of claitn 8, wherein the automotive gear is in a manual trans-mission.
./0. The method of claim 8 or 13, wherein the automotive gear is on an axle.
H. The method of claim 8, 13 or 14, wherein the automotive gear is on a differential.

AMENDED SHEET
Date Recue/Date Received 2020-07-03