WO2024030899A1

WO2024030899A1 - Lubricating oil composition for corrosion control

Info

Publication number: WO2024030899A1
Application number: PCT/US2023/071419
Authority: WO
Inventors: Peter Kleijwegt; Kevin M. ZEVENBERGEN
Original assignee: Chevron Oronite Co LLC
Current assignee: Chevron Oronite Co LLC
Priority date: 2022-08-01
Filing date: 2023-08-01
Publication date: 2024-02-08
Anticipated expiration: 2025-02-01
Also published as: KR20250048290A; CN119604603A; CA3261050A1; EP4565671A1; JP2025525167A

Abstract

A lubricating oil composition is disclosed. The composition includes a major amount of an oil of lubricating viscosity, one or more alkylhydroxybenzoate compound derived from isomerized normal alpha olefins, and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine. The molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition. The diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.

Description

LUBRICATING OIL COMPOSITION FOR CORROSION CONTROL

INVENTORS: Peter KLEIJWEGT; Kevin ZEVENBERGEN

TECHNICAL FIELD

[001] This disclosure relates to lubricating oil compositions. More specifically, this disclosure relates to lubricating oil formulations designed to improve corrosion control.

BACKGROUND

[002] Antioxidants are widely used as additives that can impart one or more performance benefits to a lubricant. These benefits include extending drain interval, maintaining viscosity, reducing deposit, reducing foam formation, protecting against corrosion and/or protecting against high temperatures. One potential complication for lubricant formulators is that antioxidants are not always fully compatible with other components. For example, the combination of antioxidant(s) and alkylhydroxybenzoate ("salicylate") detergent(s) can negatively impact a lubricant's ability to resist corrosion.

SUMMARY

[003] In one aspect, there is provided a lubricating oil composition comprising: major amount of an oil of lubricating viscosity; one or more alkyl hydroxybenzoate compound derived from isomerized normal alpha olefins; and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine; wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition. [004] In another aspect, there is provided a method for reducing copper corrosion in an engine, the method comprising: lubricating the engine with a lubricating oil composition comprising: major amount of an oil of lubricating viscosity; one or more alkylhydroxybenzoate compound derived from isomerized normal alpha olefins; and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine; wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.

[005] In yet another aspect, there is provided a lubricating oil composition comprising: major amount of an oil of lubricating viscosity; one or more alkylhydroxybenzoate compound derived from C10-C40 isomerized normal alpha olefins; and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine; wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.

DETAILED DESCRIPTION

[006] It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein.

[007] The present disclosure relates to a lubricating oil composition formulated to enhance or improve resistance against corrosion. The lubricating oil composition of this disclosure includes an alkyl hydroxybenzoate detergent and an oxidation inhibitor system comprising at least two different antioxidants. [008] More particularly, it has been unexpectedly discovered that alkylhydroxybenzoate or its alkyl group comprising or derived from isomerized normal alpha olefins provide improved resistance against corrosion when formulated in combination with antioxidants.

[009] In some embodiments, the lubricating oil composition of the present disclosure includes (a) major amount of an oil of lubricating viscosity, (b) one or more alkylhydroxybenzoate or its alkyl group comprising or derived from C10-C40 isomerized normal alpha olefins, and (c) (i) oxidation inhibitor system comprising molybdenum compound present in an amount to contribute 120 ppm or more of Mo and (ii) diphenylamine present in 0.5 wt. % or more based on the lubricating oil composition.

Alkylhydroxybenzoate Detergent

[010] The lubricating oil composition of the present disclosure includes one or more alkyl hydroxybenzoate detergents comprising or is derived from C10-C40 isomerized normal alpha olefins (NAO). In some embodiments, the alkyl group of the alkylhydroxybenzoate comprises or is derived from the isomerized NAO. In some embodiments, the manufacture of alkyl hydroxybenzoate involves the step of alkylating a phenol or another aromatic precursor with the isomerized NAO.

[011] Detergent used in engine oil is usually an anionic material that contains a long chain hydrophobic portion of the molecule and a smaller anionic or oleophobic hydrophilic portion of the molecule. The long chain hydrophobic portion of an alkylhydroxybenzoate detergent of this disclosure is the isomerized NAO. The anionic portion of an alkylhydroxybenzoate detergent is derived from carboxylic acid. The counterion is typically an alkaline earth metal or alkali metal.

[012] The alkyhydroxybenzoate detergent of this disclosure may be represented by the following generalized structure:

wherein R" is a C10-C40 alkyl group (i.e., having 10 to 40 carbon atoms); n is an integer from 1 to 4; and M is an alkaline earth metal (e.g., Ca or Mg).

[013] In some embodiments, the C10-C40 alkyl group is an isomerized normal alpha olefins (NAO) having an isomerization level (i) from about 0.10 to about 0.40, such as from 0.10 to 0.35, from 0.10 to 0.30, from 0.10 to 0.25, from 0.10 to 0.20, from 0.10 to 0.15, from 0.15 to 0.35, 0.15 to 0.30, 0.15 to 0.25, 0.15 to 0.20, 0.20 to 0.40, 0.20 to 0.35, 0.20 to 0.30, 0.20 to 0.25, 0.25 to 0.40, 0.25 to 0.35, 0.25 to 0.30, 0.30 to 0.40, 0.30 to 0.35, or 0.35 to 0.40.

[014] In some embodiments, the isomerization level is from about 0.12 to about 0.30, from about 0.12 to about 0.25, from about 0.12 to about 0.23, from about 0.12 to about 0.22, from about 0.12 to about 0.20, from about 0.13 to about 0.19, from about 0.14 to about 0.18, or from about 0.15 to about 0.17.

[015] The isomerization level (i) of an olefin can be determined by ¹ H-NMR. More specifically, the isomerization level (i) represents the relative amount of methyl groups (-CH3) (chemical shift 0.3-1.01 ppm) attached to the methylene backbone groups (-CH2-) (chemical shift 1.01 -1.38 ppm). The equation for isomerization level (i) is as follows:

Isomerization Level = m/(m + n) where m is NMR integral for methyl groups with chemical shifts between 0.3 ± 0.03 to 1.01 ± 0.03 ppm and n is NMR integral for methylene groups with chemical shifts between 1.01 ± 0.03 to 1.38 ± 0.1 ppm.

[016] Useful alkyl hydroxybenzoate detergents can be neutral, mildly overbased, or highly overbased. In some embodiments, the lubricating oil composition may comprise alkyl hydroxybenzoate detergents with varying levels of TBN. Salts that contain stoichiometric amount of the metal are described as neutral salts. Many detergents are overbased, containing large amounts of a metal base that is achieved by reacting an excess of a metal compound (e.g., a metal hydroxide or oxide) rich an acidic gas (e.g., carbon dioxide). Overbased detergents help neutralize acidic impurities produced by the combustion process and become entrapped in the oil. The degree of overbasing generally depends on the ratio of metallic ion to anionic portion of the detergent on an equivalent basis.

[017] The alkylhydroxybenzoate detergent of this disclosure has a TBN of 10 mg KOH/g or higher on an oil-free basis as measured by ASTM D-2896, such as from 15 mg KOH/g or higher, 25 mg KOH/g or higher, 50 mg KOH/g or higher, 75 mg KOH/g or higher, 100 mg KOH/g or higher, 125 mg KOH/g or higher, 150 mg KOH/g or higher, 175 mg KOH/g or higher, 200 mg KOH/g or higher, 225 mg KOH/g or higher, 250 mg KOH/g or higher, 275 mg KOH/g or higher, 300 mg KOH/g or higher, 325 mg KOH/g or higher, 350 mg KOH/g or higher, 375 mg KOH/g or higher, 400 mg KOH/g or higher, 425 mg KOH/g or higher, 450 mg KOH/g or higher, 475 mg KOH/g or higher, 500 mg KOH/g or higher, 525 mg KOH/g or higher, 550 mg KOH/g or higher, 575 mg KOH/g or higher, 600 mg KOH/g or higher and 650 mg KOH/g or higher.

[018] In some embodiments, the alkylhydroxybenzoate detergent of this disclosure has a TBN of 10 to 650 mg KOH/g on an oil-free basis as measured by ASTM D-2896, such as 10 to 600 mg KOH/g, 10 to 550 mg KOH/g, 10 to 500 mg KOH/g, 10 to 450 mg KOH/g, 10 to 400 mg KOH/g, 10 to 350 mg KOH/g, 10 to 300 mg KOH/g, 10 to 250 mg KOH/g, 10 to 200 mg KOH/g, 10 to 150 mg KOH/g, 10 to 100 mg KOH/g, 10 to 50 mg KOH/g, 50 to 650 mg KOH/g, 50 to 600 mg KOH/g, 50 to 550 mg KOH/g, 50 to 500 mg KOH/g, 50 to 450 mg KOH/g, 50 to 400 mg KOH/g, 50 to 350 mg KOH/g, 50 to 300 mg KOH/g, 50 to 250 mg KOH/g, 50 to 200 mg KOH/g, 50 to 150 mg KOH/g, 50 to 100 mg KOH/g, 100 to 650 mg KOH/g, 100 to 600 mg KOH/g, 100 to 550 mg KOH/g, 100 to 500 mg KOH/g, 100 to 450 mg KOH/g, 100 to 400 mg KOH/g, 100 to 350 mg KOH/g, 100 to 300 mg KOH/g, 100 to 250 mg KOH/g, 100 to 200 mg KOH/g, 100 to 150 mg KOH/g, 150 to 650 mg KOH/g, 150 to 600 mg KOH/g, 150 to 550 mg KOH/g, 150 to 500 mg KOH/g, 150 to 450 mg KOH/g, 150 to 400 mg KOH/g, 150 to 350 mg KOH/g, 150 to 300 mg KOH/g, 150 to 250 mg KOH/g, 150 to 200 mg KOH/g, 200 to 650 mg KOH/g, 200 to 600 mg KOH/g, 200 to 550 mg KOH/g, 200 to 500 mg KOH/g, 200 to 450 mg KOH/g, 200 to 400 mg KOH/g, 200 to 350 mg KOH/g, 200 to 300 mg KOH/g, 200 to 250 mg KOH/g, 250 to 650 mg KOH/g, 250 to 600 mg KOH/g, 250 to 550 mg KOH/g, 250 to 500 mg KOH/g, 250 to 450 mg KOH/g, 250 to 400 mg KOH/g, 250 to 350 mg KOH/g, 250 to 300 mg KOH/g, 300 to 650 mg KOH/g, 300 to 600 mg KOH/g, 300 to 550 mg KOH/g, 300 to 500 mg KOH/g, 300 to 450 mg KOH/g, 300 to 400 mg KOH/g, 300 to 350 mg KOH/g, 350 to 650 mg KOH/g, 350 to 600 mg KOH/g, 350 to 550 mg KOH/g, 350 to 500 mg KOH/g, 350 to 450 mg KOH/g, 350 to 400 mg KOH/g, 400 to 650 mg KOH/g, 400 to 600 mg KOH/g, 400 to 550 mg KOH/g, 400 to 500 mg KOH/g, 400 to 450 mg KOH/g, 450 to 650 mg KOH/g, 450 to 600 mg KOH/g, 450 to 550 mg KOH/g, 450 to 500 mg KOH/g, 500 to 650 mg KOH/g, 500 to 600 mg KOH/g, 500 to 550 mg KOH/g, 550 to 650 mg KOH/g, 550 to 600 mg KOH/g, or 600 to 650 mg KOH/g.

[019] In some embodiments, the alkylhydroxybenzoate detergent of this disclosure has a TBN of 10 to 150 mg KOH/g on an oil-free basis, such as from 10 to 140 mg KOH/g, 10 to 130 mg KOH/g, 10 to 120 mg KOH/g, 10 to 110 mg KOH/g, 10 to 100 mg KOH/g, 10 to 90 mg KOH/g, 10 to 80 mg KOH/g, 10 to 70 mg KOH/g, 10 to 60 mg KOH/g, 10 to 50 mg KOH/g, 10 to 40 mg KOH/g, 10 to 30 mg KOH/g, 10 to 20 mg KOH/g, 20 to 150 mg KOH/g, 20 to 140 mg KOH/g, 20 to 130 mg KOH/g, 20 to 120 mg KOH/g, 20 to 1 10 mg KOH/g, 20 to 100 mg KOH/g, 20 to 90 mg KOH/g, 20 to 80 mg KOH/g, 20 to 70 mg KOH/g, 20 to 60 mg KOH/g, 20 to 50 mg KOH/g, 20 to 40 mg KOH/g, 20 to 30 mg KOH/g, 30 to 150 mg KOH/g, 30 to 140 mg KOH/g, 30 to 130 mg KOH/g, 30 to 120 mg KOH/g, 30 to 110 mg KOH/g, 30 to 100 mg KOH/g, 30 to 90 mg KOH/g, 30 to 80 mg KOH/g, 30 to 70 mg KOH/g, 30 to 60 mg KOH/g, 30 to 50 mg KOH/g, 30 to 40 mg KOH/g, 40 to 150 mg KOH/g, 40 to 140 mg KOH/g, 40 to 130 mg KOH/g, 40 to 120 mg KOH/g, 40 to 110 mg KOH/g, 40 to 100 mg KOH/g, 40 to 90 mg KOH/g, 40 to 80 mg KOH/g, 40 to 70 mg KOH/g, 40 to 60 mg KOH/g, 40 to 50 mg KOH/g, 50 to 150 mg KOH/g, 50 to 140 mg KOH/g, 50 to 130 mg KOH/g, 50 to 120 mg KOH/g, 50 to 110 mg KOH/g, 50 to 100 mg KOH/g, 50 to 90 mg KOH/g, 50 to 80 mg KOH/g, 50 to 70 mg KOH/g, 50 to 60 mg KOH/g, 60 to 150 mg KOH/g, 60 to 140 mg KOH/g, 60 to 130 mg KOH/g, 60 to 120 mg KOH/g, 60 to 110 mg KOH/g, 60 to 100 mg KOH/g, 60 to 90 mg KOH/g, 60 to 80 mg KOH/g, 60 to 70 mg KOH/g, 80 to 150 mg KOH/g, 80 to 140 mg KOH/g, 80 to 130 mg KOH/g, 80 to 120 mg KOH/g, 80 to 110 mg KOH/g, 80 to 100 mg KOH/g, 80 to 90 mg KOH/g, 90 to 150 mg KOH/g, 90 to 140 mg KOH/g, 90 to 130 mg KOH/g, 90 to 120 mg KOH/g, 90 to 110 mg KOH/g, 90 to 100 mg KOH/g, 100 to 150 mg KOH/g, 100 to 140 mg KOH/g, 100 to 130 mg KOH/g, 100 to 120 mg KOH/g, 100 to 110 mg KOH/g, 110 to 150 mg KOH/g, 110 to 140 mg KOH/g, 110 to 130 mg KOH/g, 110 to 120 mg KOH/g, 120 to 150 mg KOH/g, 120 to 140 mg KOH/g, 120 to 130 mg KOH/g, 130 to 150 mg KOH/g, 130 to 140 mg KOH/g, or 140 to 150 mg KOH/g.

[020] In some embodiments, the alkylhydroxybenzoate detergent has a TBN of 10 to 300 mg KOH/g on an oil-free basis. In some embodiments, the alkylhydroxybenzoate detergent has a TBN of 600 mg KOH/g or more on an oil-free basis.

[021] The synthesis of alkyl hydroxybenzoate compounds is generally known. For example, one synthetic pathway of an overbased metal alkyl hydroxybenzoate detergent begins by reacting an alkylphenol with a metal base. The product is then carboxylated (i.e., treated with CO2) and acidified. The resulting acid product can be neutralized by lime and overbased. Some of these steps (e.g., the second neutralization and overbasing) can proceed concurrently. A more detailed description of this process can be found in US 8,030,258, which is hereby incorporated by reference.

[022] The counterion of the alkyl hydroxybenzoate detergent is typically an alkaline earth metal such as calcium or magnesium. In some embodiments, the lubricating oil composition comprises both Ca and Mg containing alkylhydroxybenzoates.

[023] In some embodiments, a calcium-containing alkylhydroxybenzoate may be present in an amount to provide about 500 to about 5000 ppm of calcium to the lubricating oil composition, such as from about 500 to about 4500 ppm, 500 to 4000 ppm, 500 to 3500 ppm, 500 to 3000 ppm, 500 to 2500 ppm, 500 to 2000 ppm, 500 to 1500 ppm, 500 to 1000 ppm, 1000 to 5000 ppm, 1000 to 4500 ppm, 1000 to 4000 ppm, 1000 to 3500 ppm, 1000 to 3000 ppm, 1000 to 2500 ppm, 1000 to 2000 ppm,

1000 to 1500 ppm, 1500 to 5000 ppm, 1500 to 4500 ppm, 1500 to 4000 ppm, 1500 to 3500 ppm, 1500 to 3000 ppm, 1500 to 2500 ppm, 1500 to 2000 ppm, 2000 to 5000 ppm, 2500 to 4500 ppm, 2500 to 4000 ppm, 2500 to 3500 ppm, 2500 to 3000 ppm,

3000 to 5000 ppm, 3000 to 4500 ppm, 3000 to 4000 ppm, 3000 to 3500 ppm, 3500 to 5000 ppm, 3500 to 4500 ppm, 3500 to 4000 ppm, 4000 to 5000 ppm, 4000 to 4500 ppm, or 4500 to 5000 ppm.

[024] In some embodiments, a magnesium-containing alkylhydroxybenzoate may be present in an amount to provide about 500 to about 5000 ppm of magnesium to the lubricating oil composition, such as from about 500 to about 4500 ppm, 500 to 4000 ppm, 500 to 3500 ppm, 500 to 3000 ppm, 500 to 2500 ppm, 500 to 2000 ppm, 500 to 1500 ppm, 500 to 1000 ppm, 1000 to 5000 ppm, 1000 to 4500 ppm, 1000 to 4000 ppm, 1000 to 3500 ppm, 1000 to 3000 ppm, 1000 to 2500 ppm, 1000 to 2000 ppm, 1000 to 1500 ppm, 1500 to 5000 ppm, 1500 to 4500 ppm, 1500 to 4000 ppm,

1500 to 3500 ppm, 1500 to 3000 ppm, 1500 to 2500 ppm, 1500 to 2000 ppm, 2000 to 5000 ppm, 2500 to 4500 ppm, 2500 to 4000 ppm, 2500 to 3500 ppm, 2500 to 3000 ppm, 3000 to 5000 ppm, 3000 to 4500 ppm, 3000 to 4000 ppm, 3000 to 3500 ppm, 3500 to 5000 ppm, 3500 to 4500 ppm, 3500 to 4000 ppm, 4000 to 5000 ppm, 4000 to 4500 ppm, or 4500 to 5000 ppm.

[025] In some embodiments, the total amount of calcium-containing alkylhydroxybenzoate and magnesium-containing alkyl hydroxybenzoate is such that the total amount of calcium and magnesium in the lubricating oil composition is from about 500 to about 5000 ppm, such as from about from about 500 to about 4500 ppm, 500 to 4000 ppm, 500 to 3500 ppm, 500 to 3000 ppm, 500 to 2500 ppm, 500 to 2000 ppm, 500 to 1500 ppm, 500 to 1000 ppm, 1000 to 5000 ppm, 1000 to 4500 ppm, 1000 to 4000 ppm, 1000 to 3500 ppm, 1000 to 3000 ppm, 1000 to 2500 ppm, 1000 to 2000 ppm, 1000 to 1500 ppm, 1500 to 5000 ppm, 1500 to 4500 ppm, 1500 to 4000 ppm, 1500 to 3500 ppm, 1500 to 3000 ppm, 1500 to 2500 ppm, 1500 to 2000 ppm, 2000 to 5000 ppm, 2500 to 4500 ppm, 2500 to 4000 ppm, 2500 to 3500 ppm, 2500 to 3000 ppm, 3000 to 5000 ppm, 3000 to 4500 ppm, 3000 to 4000 ppm, 3000 to 3500 ppm, 3500 to 5000 ppm, 3500 to 4500 ppm, 3500 to 4000 ppm, 4000 to 5000 ppm, 4000 to 4500 ppm, or 4500 to 5000 ppm.

[026] In general, the total amount of Ca and Mg present in the lubricating oil composition is about 5000 ppm or less. The ppm values are based on total weight of the lubricating oil composition.

Oxidation Inhibitor System

[027] The lubricating oil composition of this disclosure comprises an oxidation inhibitor system comprising at least two antioxidant compounds. The antioxidant compounds include (i) a molybdenum-containing antioxidant and (ii) a diphenylamine antioxidant.

[028] The molybdenum or molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition, such as at least 130 ppm, at least 140 ppm, at least 150 ppm, at least 160 ppm, at least 170, at least 180 ppm, at least 190 ppm, and at least 200 ppm. Examples of molybdenum- containing antioxidants include molybdenum succinimide, molybdenum dithiocarbamate, and trinuclear molybdenum compounds. Molybdenum succinimide

[029] In one embodiment, the molybdenum amine is a molybdenumsuccinimide complex. Suitable molybdenum-succinimide complexes are described, for example, in U.S. Patent No. 8,076,275. These complexes are prepared by a process comprising reacting an acidic molybdenum compound with an alkyl or alkenyl succinimide of a polyamine below:

wherein R is a C24 to C350 (e.g., C70 to C128) alkyl or alkenyl group; R' is a straight or branched-chain alkylene group having 2 to 3 carbon atoms; x is 1 to 11; and y is 1 to 11.

[030] The molybdenum compounds used to prepare the molybdenumsuccinimide complex are acidic molybdenum compounds or salts of acidic molybdenum compounds. By "acidic" is meant that the molybdenum compounds will react with a basic nitrogen compound as measured by ASTM D664 or D2896. Generally, the acidic molybdenum compounds are hexavalent. Representative examples of suitable molybdenum compounds include molybdenum trioxide, molybdic acid, ammonium molybdate, sodium molybdate, potassium molybdate and other alkaline metal molybdates and other molybdenum salts such as hydrogen salts, (e.g., hydrogen sodium molybdate), MoOCk, MoO₂Br₂, MO2O3CI6, and the like.

[031] The succinimides that can be used to prepare the molybdenumsuccinimide complex are disclosed in numerous references and are well known in the art. Certain fundamental types of succinimides and the related materials encompassed by the term of art "succinimide" are taught in U.S. Patent Nos. 3,172,892; 3,219,666; and 3,272,746. The term "succinimide" is understood in the art to include many of the amide, imide, and amidine species which may also be formed. The predominant product however is a succinimide and this term has been generally accepted as meaning the product of a reaction of an alkyl or alkenyl substituted succinic acid or anhydride with a nitrogen-containing compound. Preferred succinimides are those prepared by reacting a polyisobutenyl succinic anhydride of about 70 to 128 carbon atoms with a polyamine.

[032] Preferred polyamines may have 2 to 60 carbon atoms and from 2 to 12 nitrogen atoms per molecule. Particularly preferred amines include polyalkyleneamines represented by the formula:

NH₂(CH₂)n— (NH(CH₂)n)m— NH₂ wherein n is 2 to 3 and m is 0 to 10. Illustrative examples include ethylene diamine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, tetrapropylene pentamine, pentaethylene hexamine and the like, as well as the commercially available mixtures of such polyamines.

[033] The molybdenum-succinimide complex may be post-treated with a sulfur source at a suitable pressure and a temperature not to exceed 120°C to provide a sulfurized molybdenum-succinimide complex. The sulfurization step may be carried out for a period of from about 0.5 to 5 hours (e.g., 0.5 to 2 hours). Suitable sources of sulfur include elemental sulfur, hydrogen sulfide, phosphorus pentasulfide, organic polysulfides of formula RaS_x where R is hydrocarbyl (e.g., Ci to C10 alkyl) and x is at least 3, Ci to C10 mercaptans, inorganic sulfides and polysulfides, thioacetamide, and thiourea.

Molybdenum Dithiocarbamate

[034] Suitable molybdenum dithiocarbamates include any molybdenum dithiocarbamate which can be used as an additive for lubricating oils. One class of molybdenum dithiocarbamates for use herein is represented by the following:

wherein R³, R⁴, R⁵, and R⁵ are each independently hydrogen or a hydrocarbon group including, by way of example, alkyl groups, alkenyl groups, aryl groups, cycloalkyl groups and cycloalkenyl groups, and X¹, X², X³ and X⁴ are each independently sulfur or oxygen.

[035] Suitable alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, tertiary butyl, pentyl, isopentyl, secondary pentyl, neopentyl, tertiary pentyl, hexyl, secondary hexyl, heptyl, secondary heptyl, octyl, 2-ethylhexyl, secondary octyl, nonyl, secondary nonyl, decyl, secondary decyl, undecyl, secondary undecyl, dodecyl, secondary dodecyl, tridecyl, isotridecyl, secondary tridecyl, tetradecyl, secondary tetradecyl, hexadecyl, secondary hexadecyl, stearyl, icosyl, docosyl, tetracosyl, triacontyl, 2-butyloctyl, 2-butyldecyl, 2-hexyloctyl, 2- hexyldecyl, 2-octyldecyl, 2-hexyldodecyl, 2-octyldodecyl, 2-decyltetradecyl, 2- dodecylhexadecyl, 2-hexadecyloctadecyl, 2-tetradecyloctadecyl, monomethyl branched-isostearyl and the like. [036] Suitable alkenyl groups include, but are not limited to, vinyl, allyl, propenyl, butenyl, isobutenyl, pentenyl, isopentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tetradecenyl, oleyl and the like.

[037] Suitable aryl groups include, but are not limited to, phenyl, tolyl, xylyl, cumenyl, mesityl, benzyl, phenethyl, styryl, cinnamyl, benzhydryl, trityl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, heptylphenyl, octylphenyl, nonylphenyl, decylphenyl, undecylphenyl, dodecylphenyl, biphenyl, benzylphenyl, styrenated phenyl, p-cumylphenyl, alpha-naphthyl, beta-naphthyl groups and the like.

[038] Suitable cycloalkyl groups and cycloalkenyl groups include, but are not limited to, cyclopentyl, cyclohexyl, cycloheptyl, methylcyclopentyl, methylcyclohexyl, methylcycloheptyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, methylcyclopentenyl, methylcyclohexenyl, methylcycloheptenyl groups and the like.

[039] In an embodiment, X¹ to X⁴ are independently selected from sulfur or oxygen atom, and all of X¹ to X⁴ may be a sulfur atom or an oxygen atom, or a mixture of sulfur atoms and oxygen atoms. In consideration of balance between friction reducing effect and corrosivity, the molar ratio (ratio of numbers) of sulfur atom(s)/oxygen atom(s) should particularly preferably be in the range from about 1/3 to about 3/1.

[040] Some of the oil-soluble or dispersed oil-stable molybdenum compounds are commercially available. For example, products where X¹ and X² are O, X³ and X⁴ are S, and where R³ to R⁵ are C13H27 aliphatic hydrocarbyl groups and where the molybdenum is in oxidation state V are sold under the trademarks Molyvan 807 and Molyvan 822 as antioxidants and friction reducing additives by R.T. Vanderbilt Company Inc. (Norwalk, Conn. USA). These molybdenum compounds may be prepared by the methods described in U.S. Pat. No. 3,356,702 wherein MoOs is converted to soluble molybdate by dissolving in alkali metal hydroxide solution, neutralized by the addition of acid followed by the addition of a secondary amine and carbon disulfide. In another aspect, X¹ to X⁴ are O or S may be prepared by a number of methods known in the art such as, for example, U.S. Pat. Nos. 4,098,705 and 5,631,213. [041] Generally, the sulfurized oxymolybdenum dithiocarbamates can be prepared by reacting molybdenum trioxide or a molybdate with an alkali sulfide or an alkali hydrosulfide, and subsequently adding carbon disulfide and a secondary amine to the reaction mixture and reacting the resultant mixture at an adequate temperature. To prepare the asymmetric sulfurized oxymolybdenum dithiocarbamates, the use of a secondary amine having different hydrocarbon groups or the use of two or more different secondary amines in the above process is sufficient. The symmetric sulfurized oxymolybdenum dithiocarbamates can also be prepared in a similar manner, but with the use of only one secondary amine.

[042] Examples of suitable molybdenum dithiocarbamate compounds include, but are not limited to, sulfurized molybdenum diethyldithiocarbamate, sulfurized molybdenum dipropyldithiocarbamate, sulfurized molybdenum dibutyldithiocarbamate, sulfurized molybdenum dipentyldithiocarbamate, sulfurized molybdenum dihexyldithiocarbamate, sulfurized molybdenumn dioctyldithiocarbamate, sulfurized molybdenum didecyldithiocarbamate, sulfurized molybdenum didodecyldithiocarbamate, sulfurized molybdenum ditridecyldithiocarbamate, sulfurized molybdenum di(butylphenyl)dithiocarbamate, sulfurized molybdenum di(nonylphenyl)dithiocarbamate, sulfurized oxymolybdenum diethyldithiocarbamate, sulfurized oxymolybdenum dipropyldithiocarbamate, sulfurized oxymolybdenum dibutyldithiocarbamate, sulfurized oxymolybdenum dipentyldithiocarbamate, sulfurized oxymolybdenum dihexyldithiocarbamate, sulfurized oxymolybdenum dioctyldithiocarbamate, sulfurized oxymolybdenum didecyldithiocarbamate, sulfurized oxymolybdenum didodecyldithiocarbamate, sulfurized oxymolybdenum ditridecyldithiocarbamate, sulfurized oxymolybdenum di(butylphenyl)dithiocarbamate, sulfurized oxymolybdenum di(nonylphenyl)dithiocarbamate, all of which the alkyl groups may be straight-chain or branched, and the like and mixtures thereof.

Trinuclear Molybdenum Compounds [043] Suitable molybdenum-containing antioxidants also include trinuclear molybdenum compounds such as trinuclear molybdenum dialkyldithiocarbamates which are known in the art, as taught by U.S. Pat. Nos. 5,888,945 and 6,010,987, herein incorporated by reference.

[044] In some embodiments, the trinuclear molybdenum compounds may have be represented by chemical formulas MosS4(dtc)4, MosSsfdtc)^ Mo3S4(dtc)6, and Mo3S?(dtc)4 and mixtures thereof wherein dtc represents independently selected diorganodithiocarbamate ligands containing independently selected organo groups and wherein the ligands have a sufficient number of carbon atoms among all the organo groups of the compound's ligands are present to render the compound soluble or dispersible in the lubricating oil.

Diphenylamine

[045] Diphenylamine are aromatic amine antioxidants and may have one or more carbon-based substituent groups. Diphenylamine-type oxidation inhibitors include, but are not limited to, alkylated diphenylamine, phenyl-a-naphthylamine, and alkyl or arylalkyl substituted phenyl-a-naphthylamine, alkylated p-phenylene diamines, and tetramethyl-diaminodiphenylamine.

[046] Specific examples of diphenylamine antioxidants include bis-nonylated diphenylamine, bis-octylated diphenylamine, and octylated/butylated diphenylamine, 4,4'-dioctyldiphenylamine, 4,4'-dinonyldiphenylamine, N-phenyl-1 -naphthylamine, N- (4-tert-octyphenyl)-1 -naphthylamine, and N-(4-octylphenyl)-1 -naphthylamine.

[047] Diphenylamine antioxidants may be present at 0.01 to 5 wt. % of the lubricating oil composition, such as 0.01 to 4.5 wt. %, 0.01 to 4.0 wt. %, 0.01 to 3.5 wt. %, 0.01 to 3.0 wt. %, 0.01 to 2.5 wt. %, 0.01 to 2.0 wt. %, 0.01 to 1.5 wt. %, 0.01 to 1.0 wt. %, 0.01 to 0.5 wt. %, 0.5 to 5.0 wt. %, 0.5 to 4.5 wt. %, 0.5 to 4.0 wt. %, 0.5 to 3.5 wt. %, 0.5 to 3.0 wt. %, 0.5 to 2.5 wt. %, 0.5 to 2.0 wt. %, 0.5 to 1.5 wt. %, 0.5 to 1.0 wt. %,

1.0 to 5.0 wt. %, 1.0 to 4.5 wt. %, 1.0 to 4.0 wt. %, 1.0 to 3.5 wt. %, 1.0 to 3.0 wt. %, 1.0 to 2.5 wt. %, 1.0 to 2.0 wt. %, 1.0 to 1.5 wt. %, 1.5 to 5.0 wt. %, 1.5 to 4.5 wt. %, 1.5 to

4.0 wt. %, 1.5 to 3.5 wt. %, 1.5 to 3.0 wt. %, 1.5 to 2.5 wt. %, 1.5 to 2.0 wt. %, 2.0 to 5.0 wt. %, 2.0 to 4.5 wt. %, 2.0 to 4.0 wt. %, 2.0 to 3.5 wt. %, 2.0 to 3.0 wt. %, 2.0 to 2.5 wt. %, 2.5 to 5.0 wt. %, 2.5 to 4.5 wt. %, 2.5 to 4.0 wt. %, 2.5 to 3.5 wt. %, 2.5 to 3.0 wt. %, 3.0 to 5.0 wt. %, 3.0 to 4.5 wt. % 3.0 to 4.0 wt. %, 3.0 to 3.5 wt. %, 3.5 to 5.0 wt. %, 3.5 to 4.5 wt. %, 3.5 to 4.0 wt. %, 4.0 to 5.0 wt. %, 4.0 to 4.5 wt. %, or 4.5 to 5.0 wt. %.

Optional Additives

[048] Optionally, the lubricating oil composition may comprise a hindered phenolic antioxidant. Examples of hindered phenolic antioxidants include 2,6-di-tert- butylphenol, 2,6-di-tert-butyl-p-cresol, and 2,6-di-tert-butyl-4-(2-octyl-3-propanoic) phenol.

[049] The hindered phenolic antioxidant may be present at 0.01 to 5 wt. % of the lubricating oil composition, such as 0.01 to 4.5 wt. %, 0.01 to 4.0 wt. %, 0.01 to 3.5 wt. %, 0.01 to 3.0 wt. %, 0.01 to 2.5 wt. %, 0.01 to 2.0 wt. %, 0.01 to 1.5 wt. %, 0.01 to 1.0 wt. %, 0.01 to 0.5 wt. %, 0.5 to 5.0 wt. %, 0.5 to 4.5 wt. %, 0.5 to 4.0 wt. %, 0.5 to 3.5 wt. %, 0.5 to 3.0 wt. %, 0.5 to 2.5 wt. %, 0.5 to 2.0 wt. %, 0.5 to 1.5 wt. %, 0.5 to 1.0 wt.

%, 1.0 to 5.0 wt. %, 1.0 to 4.5 wt. %, 1.0 to 4.0 wt. %, 1.0 to 3.5 wt. %, 1.0 to 3.0 wt. %,

1.0 to 2.5 wt. %, 1.0 to 2.0 wt. %, 1.0 to 1.5 wt. %, 1.5 to 5.0 wt. %, 1.5 to 4.5 wt. %, 1.5 to 4.0 wt. %, 1.5 to 3.5 wt. %, 1.5 to 3.0 wt. %, 1.5 to 2.5 wt. %, 1.5 to 2.0 wt. %, 2.0 to

5.0 wt. %, 2.0 to 4.5 wt. %, 2.0 to 4.0 wt. %, 2.0 to 3.5 wt. %, 2.0 to 3.0 wt. %, 2.0 to 2.5 wt. %, 2.5 to 5.0 wt. %, 2.5 to 4.5 wt. %, 2.5 to 4.0 wt. %, 2.5 to 3.5 wt. %, 2.5 to 3.0 wt. %, 3.0 to 5.0 wt. %, 3.0 to 4.5 wt. % 3.0 to 4.0 wt. %, 3.0 to 3.5 wt. %, 3.5 to 5.0 wt. %, 3.5 to 4.5 wt. %, 3.5 to 4.0 wt. %, 4.0 to 5.0 wt. %, 4.0 to 4.5 wt. %, or 4.5 to 5.0 wt. %.

Succinimides

[050] Optionally, the lubricating oil composition may include polyalkenyl succinimide dispersants such as those described herein. In general, the nitrogen content from the nitrogen-containing dispersant based on the lubricating oil composition is from about 0.010 wt % to about 0.30 wt % such as from about 0.050 to about 0.25 wt %, about 0.050 to about 0.20 wt %, and about 0.050 to about 0.15 wt %.

[051] In one embodiment, a polyalkenyl bis-succinimide can be obtained by reacting a polyalkenyl-substituted succinic anhydride below

0 wherein R is a polyalkenyl substituent is derived from a polyalkene group having a number average molecular weight of from about 500 to about 3000, with a polyamine. In one embodiment, R is a polyalkenyl substituent derived from a polyalkene group having a number average molecular weight of from about 1000 to about 2500. In one embodiment, R is a polyisobutenyl substituent derived from a polyisobutene having a number average molecular weight of from about 500 to about 3000. In another embodiment, R is a polyisobutenyl substituent derived from a polyisobutene having a number average molecular weight of from about 1000 to about 2500.

[052] Suitable polyamines for use in preparing the bis-succinimide dispersants include polyalkylene polyamines. Such polyalkylene polyamines will typically contain about 2 to about 12 nitrogen atoms and about 2 to 24 carbon atoms. Particularly suitable polyalkylene polyamines are those having the formula: H2N — (R'NH)x — H wherein R' is a straight- or branched-chain alkylene group having 2 or 3 carbon atoms and x is 1 to 9. Representative examples of suitable polyalkylene polyamines include ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, pentaethylene hexamine, and heavy polyamines (e.g., Ethyleneamine E-100, available from Huntsman Company).

[053] Generally, the polyalkenyl-substituted succinic anhydride is reacted with the polyamine at a temperature of about 130°C to about 220°C (e.g., 145°C to 175°C). The reaction can be carried out under an inert atmosphere, such as nitrogen or argon. Generally, a suitable molar charge of polyamine to polyalkenyl-substituted succinic anhydride is from about 0.35:1 to about 0.6:1 (e.g., 0.4:1 to 0.5:1). As used herein, the "molar charge of polyamine to polyalkenyl-substituted succinic anhydride" means the ratio of the number of moles of polyamine to the number of succinic groups in the succinic anhydride reactant.

[054] One class of suitable polyalkenyl succinimides may be represented by the following:

0 0 wherein R and R' are as described herein above and y is 1 to 11.

Post-Treatment of Polyalkenyl Succinimide

[055] In some embodiments, the succinimide dispersant may be post-treated by a reactive boron compound or organic carbonate.

[056] Suitable boron compounds that can be used as a source of boron include, for example, boric acid, a boric acid salt, a boric acid ester, and the like. Representative examples of a boric acid include orthoboric acid, metaboric acid, paraboric acid, and the like. Representative examples of a boric acid salt include ammonium borates, such as ammonium metaborate, ammonium tetraborate, ammonium pentaborate, ammonium octaborate, and the like. Representative examples of a boric acid ester include monomethyl borate, dimethyl borate, trimethyl borate, monoethyl borate, diethyl borate, triethyl borate, monopropyl borate, dipropyl borate, tripropyl borate, monobutyl borate, dibutyl borate, tributyl borate, and the like.

[057] In some embodiments, the lubricating oil composition includes both borated and non-borated succinimides. In some embodiments, the mass ratio of borated and non-borated succinimide is less than 1, such as less than 0.95, less than

0.90, less than 0.85, and less than 0.80.

Lubricating Oil [058] The oil of lubricating viscosity (sometimes referred to as "base stock" or "base oil") is the primary liquid constituent of a lubricant, into which additives and possibly other oils are blended, for example to produce a final lubricant (or lubricant composition). A base oil, which is useful for making concentrates as well as for making lubricating oil compositions therefrom, may be selected from natural (vegetable, animal or mineral) and synthetic lubricating oils and mixtures thereof.

[059] Oils used as the base oil will be selected or blended depending on the desired end use and the additives in the finished oil to give the desired grade of engine oil. In one embodiment, the lubricating oil composition is a multi-grade oil for heavy duty or passenger car. The multi-grade oil may have a Society of Automotive Engineers (SAE) viscosity grade of OW-8, 0W- 12, OW-16, 0W-20, 0W-30, 0W-40, 0W- 50, 0W-60, 5W, 5W-20, 5W-30, 5W-40, 5W- 50, 5W-60, 10W, 10W-20, 10W-30, 10W- 40, 10W-50, 15W, 15W-20, 15W-30, 15W-40, 20W-40 or 20W-50.

[060] Definitions for the base stocks and base oils in this disclosure are the same as those found in American Petroleum Institute (API) Publication 1509 Annex E ("API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils," February 2022). Group I base stocks contain less than 90% saturates and/or greater than 0.03% sulfur and have a viscosity index greater than or equal to 80 and less than 120 using the test methods specified in Table E-1. Group II base stocks contain greater than or equal to 90% saturates and less than or equal to 0.03% sulfur and have a viscosity index greater than or equal to 80 and less than 120 using the test methods specified in Table E-1. Group III base stocks contain greater than or equal to 90% saturates and less than or equal to 0.03% sulfur and have a viscosity index greater than or equal to 120 using the test methods specified in Table E-1. Group IV base stocks are polyalphaolefins (PAO). Group V base stocks include all other base stocks not included in Group I, II, III, or IV.

[061] Natural oils include animal oils, vegetable oils (e.g., castor oil and lard oil), and mineral oils. Animal and vegetable oils possessing favorable thermal oxidative stability can be used. Of the natural oils, mineral oils are preferred. Mineral oils vary widely as to their crude source, for example, as to whether they are paraffinic, naphthenic, or mixed paraffinic-naphthenic. Oils derived from coal or shale are also useful. Natural oils vary also as to the method used for their production and purification, for example, their distillation range and whether they are straight run or cracked, hydrorefined, or solvent extracted.

[062] Synthetic oils include hydrocarbon oil. Hydrocarbon oils include oils such as polymerized and interpolymerized olefins (e.g., polybutylenes, polypropylenes, propylene isobutylene copolymers, ethylene-olefin copolymers, and ethylenealphaolefin copolymers). Polyalphaolefin (PAO) oil base stocks are commonly used synthetic hydrocarbon oil. By way of example, PAOs derived from Cs to C14 olefins, e.g., Cs, C10, C12, C14 olefins or mixtures thereof, may be utilized.

[063] Other useful fluids for use as base oils include non-conventional or unconventional base stocks that have been processed, preferably catalytically, or synthesized to provide high performance characteristics.

[064] Non-conventional or unconventional base stocks/base oils include one or more of a mixture of base stock(s) derived from one or more Gas-to-Liquids (GTL) materials, as well as isomerate/isodewaxate base stock(s) derived from natural wax or waxy feeds, mineral and or non-mineral oil waxy feed stocks such as slack waxes, natural waxes, and waxy stocks such as gas oils, waxy fuels hydrocracker bottoms, waxy raffinate, hydrocrackate, thermal crackates, or other mineral, mineral oil, or even nonpetroleum oil derived waxy materials such as waxy materials received from coal liquefaction or shale oil, and mixtures of such base stocks. Other base oils include Coal to liquid (CTL) products and alkyl-naphthalene.

[065] Base oils for use in the lubricating oil compositions of present disclosure are any of the variety of oils corresponding to API Group I, Group II, Group III, Group IV, and Group V oils, and mixtures thereof, preferably API Group II, Group III, Group IV, and Group V oils, and mixtures thereof, more preferably the Group III to Group V base oils due to their exceptional volatility, stability, viscometric and cleanliness features. [066] The lubricating oil composition may have a high temperature shear (HTHS) viscosity at 150° C of 5.2 cP or less, such as 5.1 cP or less, 5.0 cP or less, 4.5 cP or less, 4.0 cP or less, 3.9 cP or less, 3.8 cP or less, 3.7 cP or less, 3.6 cP or less, 3.5 cP or less, 3.4 cP or less, 3.3 cP or less, 3.2 cP or less, 3.1 cP or less, 3.0 cP or less, 2.9 cP or less, 2.8 cP or less, 2.7 cP or less, 2.6 cP or less, 2.5 cP or less, 2.4 cP or less, 2.3 cP or less, 2.2 cP or less, 2.1 cP or less, 2.0 cP or less, 1.9 cP or less, 1.8 cP or less, 1.7 cP or less, 1.6 cP or less, 1.5 cP or less, 1.4 cP or less, 1.3 cP or less, 1.2 cP or less, 1.1 cP or less, or 1.0 cP or less. In some embodiments, the lubricating oil composition may have a HTHS at 150°C from 1.0 to 5.2 cP, such as from 1.0 to 4.5 cP, 1.0 to 4.0 cP, 1.0 to 2.9 cP, 1.3 to 2.9 cP, 1.0 to 2.6 cP, 1.3 to 2.6 cP, 1.0 cP to 2.3 cP, 1.3 cP to 2.3 cP, 1.0 cP to 2.0 cP, 1.3 cP to 2.3 cP, 1.0 cP to 1.7 cP, or 1.3 cP to 1.7 cP. The lubricating oil composition may have a viscosity index of at least 135 (e.g., 135 to 400, or 135 to 250), at least 150 (e.g., 150 to 400, 150 to 250), at least 165 (e.g., 165 to 400, or 165 to 250), at least 190 (e.g., 190 to 400, or 190 to 250), or at least 200 (e.g., 200 to 400, or 200 to 250). If the viscosity index of the lubricating oil composition is less than 135, it may be difficult to improve fuel efficiency while maintaining the HTHS viscosity at 150° C. If the viscosity index of the lubricating oil composition exceeds 400, evaporation properties may be reduced, and deficits due to insufficient solubility of the additive and matching properties with a seal material may be caused.

[067] The base oil may have a kinematic viscosity at 100°C (ASTM D445) in a range of 1.4 to 20 mm²/s such as 3 to 12 mm²/s, such as 3 to 11 mm²/s, 3 to 10 mm²/s,

3 to 9 mm²/s, 3 to 8 mm²/s, 3 to 7 mm²/s, 3 to 6 mm²/s, 3 to 5 mm²/s, 3 to 4 mm²/s, 4 to 12 mm²/s, 4 to 11 mm²/s, 4 to 10 mm²/s, 4 to 9 mm²/s, 4 to 8 mm²/s, 4 to 7 mm²/s,

4 to 6 mm²/s, 4 to 5 mm²/s, 5 to 12 mm²/s, 5 to 11 mm²/s, 5 to 10 mm²/s, 5 to 9 mm²/s,

5 to 8 mm²/s, 5 to 7 mm²/s, 5 to 6 mm²/s, 6 to 12 mm²/s, 6 to 11 mm²/s, 6 to 10 mm²/s,

6 to 9 mm²/s, 6 to 8 mm²/s, 6 to 7 mm²/s, 7 to 12 mm²/s, 7 to 11 mm²/s, 7 to 10 mm²/s,

7 to 9 mm²/s, 7 to 10 mm²/s, 7 to 9 mm²/s, 7 to 8 mm²/s, 8 to 12 mm²/s, 8 to 11 mm²/s,

8 to 10 mm²/s, 8 to 9 mm²/s, 9 to 12 mm²/s, 9 to 11 mm²/s, 9 to 10 mm²/s, 10 to 12 mm²/s, 10 to 11 mm²/s, or 11 to 12 mm²/s. Other Additives

[068] The present lubricating oil compositions may also contain conventional lubricant additives for imparting auxiliary functions to give a finished lubricating oil composition in which these additives are dispersed or dissolved. For example, the lubricating oil compositions can be blended with antioxidants, ashless dispersants, anti-wear agents, rust inhibitors, dehazing agents, demulsifying agents, friction modifiers, metal deactivating agents, pour point depressants, viscosity modifiers, antifoaming agents, co-solvents, package compatibilizers, corrosion-inhibitors, dyes, extreme pressure agents and the like and mixtures thereof. A variety of the additives are known and commercially available. These additives, or their analogous compounds, can be employed for the preparation of the lubricating oil compositions of the invention by the usual blending procedures.

[069] Each of the foregoing additives, when used, is used at a functionally effective amount to impart the desired properties to the lubricant. Thus, for example, if an additive is an ashless dispersant, a functionally effective amount of this ashless dispersant would be an amount sufficient to impart the desired dispersancy characteristics to the lubricant. Generally, the concentration of each of these additives, when used, may range, unless otherwise specified, from about 0.001 to about 20 wt. %, such as about 0.01 to about 10 wt. %.

[070] The following non-limiting examples are illustrative of the present invention. Brief descriptions of how the examples were prepared are provided.

EXAMPLES

[071] Each of the samples described herein contained a dispersant inhibitor package containing one or more of the following:

Dispersant Inhibitor Package

1) dispersant 2) anti-wear agent

3) detergent

4) antioxidant

5) Optional friction modifier

6) Optional corrosion inhibitor

The fully formulated lubricating oil composition includes the dispersant inhibitor package and base oil. The composition may also include viscosity index improver and pour point depressant.

[072] The following describes specific detergent components used. The salicylate detergents (A, B, D) were synthesized following or substantially following the method described in U.S. Pat. No. 8,993,499. The salicylate detergent C was synthesized following or substantially following the method described in U.S. Pat. No. 8,030,258. The isomerized normal alpha olefins were obtained commercially from CP Chem.

Salicylate A

[073] Salicylate A was prepared by alkylating with C20-24 isomerized normal alpha olefin. The isomerization level of the alpha olefin is about 0.16. The resulting alkylhydroxybenzoate composition has a TBN of about 225 mg KOH/g and Ca content of 8 wt. % on an oil-free basis.

Salicylate B

[074] Salicylate B was prepared by alkylating with C20-24 isomerized normal alpha olefin. The isomerization level of the alpha olefin is about 0.16. The resulting alkylhydroxybenzoate composition has a TBN of about 630 mg KOH/g and Ca content of 22 wt. % on an oil-free basis.

Salicylate C [075] Salicylate C was prepared by alkylating with C20-28 normal alpha olefin. The resulting alkylhydroxybenzoate composition has a TBN of about 520 mg KOH/g and Ca content of 19 wt% on an oil-free basis.

Salicylate D

[076] Salicylate D was prepared by alkylating with C14-C18 normal alpha olefin. The resulting alkyl hydroxybenzoate composition has a TBN about 300 mg KOH/g and Ca content about 10.6 wt. % on an oil-free basis.

Ca Sulfonate 1

[077] Ca Sulfonate 1 is a low overbased Ca sulfonate having a TBN about 35 mg KOH/g and Ca content about 4.4 wt.% on an oil-free basis.

Ca Sulfonate 2

[078] Ca Sulfonate 2 is a highly overbased Ca Sulfonate having a TBN about 700 mg KOH/g and Ca content about 26 wt. % on an oil-free basis.

Mg Sulfonate

[079] Mg sulfonate is a medium overbased sulfonate having a TBN about 656 mg KOH/g and Mg content about 15.4 wt.% on an oil-free basis.

Phenate

[080] Phenate is a highly overbased Ca phenate having a TBN about 383 mg KOH/g and Ca content about 14 wt.% on an oil-free basis.

HTCBT Test

[081] The ASTM D6594 HTCBT protocol was used to test diesel engine lubricants to determine their tendency to corrode various metals. Four metal specimens of copper, lead, tin and phosphor bronze were immersed in a measured amount of engine oil. The oil, at an elevated temperature (170 °C), was blown with air (5 l/h) for a period of time (168 h). Afterwards, the copper specimen and the stressed oil were examined to detect corrosion and corrosion products, respectively.

[082] The concentrations of copper, lead, and tin in the new oil and stressed oil and the respective changes in metal concentrations are reported below.

[083] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[084] Likewise, the term "comprising" is considered synonymous with the term "including." Likewise whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising," it is understood that we also contemplate the same composition or group of elements with transitional phrases "consisting essentially of," "consisting of," "selected from the group of consisting of," or "is" preceding the recitation of the composition, element, or elements and vice versa.

[085] The terms "a" and "the" as used herein are understood to encompass the plural as well as the singular.

[086] Various terms have been defined above. To the extent a term used in a claim is not defined above, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are fully incorporated by reference to the extent such disclosure is not inconsistent with this application and for all jurisdictions in which such incorporation is permitted.

[087] The foregoing description of the disclosure illustrates and describes the present disclosure. Additionally, the disclosure shows and describes only the preferred embodiments but, as mentioned above, it is to be understood that the disclosure is capable of use in various other combinations, modifications, and environments and is capable of changes or modifications within the scope of the concept as expressed herein, commensurate with the above teachings and/or the skill or knowledge of the relevant art. While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

[088] It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein.

[089] The embodiments described hereinabove are further intended to explain best modes known of practicing it and to enable others skilled in the art to utilize the disclosure in such, or other, embodiments and with the various modifications required by the particular applications or uses. Accordingly, the description is not intended to limit it to the form disclosed herein. Also, it is intended that the appended claims be construed to include alternative embodiments.

Claims

1. A lubricating oil composition comprising: major amount of an oil of lubricating viscosity; one or more alkylhydroxybenzoate compound derived from isomerized normal alpha olefins; and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine; wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.

2. The lubricating oil composition of claim 1, wherein the alkylhydroxybenozate compound has a TBN of 10 to 300 mg KOH/g on an oil-free basis.

3. The lubricating oil composition of claim 1, wherein the one or more alkylhydroxybenzoate compound has a TBN of 600 mg KOH/g or greater on an oil- free basis.

4. The lubricating oil composition of claim 1, wherein the one or more alkylhydroxybenzonate compound is a mixture of alkylhydroxybenzoate compound having a TBN of 10 to 300 mg KOH/g on an oil-free basis and alkylhydroxybenzoate compound having a TBN of 600 mg KOH/g or greater on an oil-free basis.

5. The lubricating oil composition of claim 1, wherein the molybdenum-containing antioxidant is molybdenum succinimide, molybdenum dithiocarbamate, or trinuclear molybdenum compound.

6. The lubricating oil composition of claim 1, further comprising a friction modifier, viscosity index improver, corrosion inhibitor, or pour point depressant.

7. The lubricating oil composition of claim 1, wherein the isomerized normal alpha olefins contain 10 to 40 carbon atoms.

8. A method for reducing copper corrosion in an engine, the method comprising: lubricating the engine with a lubricating oil composition comprising: major amount of an oil of lubricating viscosity; one or more alkylhydroxybenzoate compound derived from isomerized normal alpha olefins; and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine; wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.

9. The method of claim 8, wherein the alkylhydroxybenozate compound has a TBN of 10 to 300 mg KOH/g on an oil-free basis.

10. The method of claim 8, wherein the one or more alkylhydroxybenzoate compound has a TBN of 600 mg KOH/g or greater on an oil-free basis.

11. The method of claim 8, wherein the one or more alkylhydroxybenzonate compound is a mixture of alkyl hydroxybenzoate compound having a TBN of 10 to 300 mg KOH/g on an oil-free basis and alkylhydroxybenzoate compound having a TBN of 600 mg KOH/g or greater on an oil-free basis.

12. The method of claim 8, wherein the molybdenum-containing antioxidant is molybdenum succinimide, molybdenum dithiocarbamate, or trinuclear molybdenum compound.

13. The method of claim 1, wherein the lubricating oil composition further comprises a friction modifier, viscosity index improver, corrosion inhibitor, or pour point depressant.

14. The method of claim 8, wherein the isomerized normal alpha olefins contain 10 to 40 carbon atoms.

15. A lubricating oil composition comprising: major amount of an oil of lubricating viscosity; one or more alkyl hydroxybenzoate compound derived from C10-C40 isomerized normal alpha olefins; and oxidation inhibitor system comprising a molybdenum-containing antioxidant and a diphenylamine; wherein the molybdenum-containing antioxidant is present in an amount to provide at least 120 ppm of Mo to the lubricating oil composition and wherein the diphenylamine is present in an amount to provide 0.5 wt. % or more to the lubricating oil composition.

16. The lubricating oil composition of claim 15, wherein the alkylhydroxybenozate compound has a TBN of 10 to 300 mg KOH/g on an oil-free basis.

17. The lubricating oil composition of claim 15, wherein the one or more alkylhydroxybenzoate compound has a TBN of 600 mg KOH/g or greater on an oil- free basis.

18. The lubricating oil composition of claim 15, wherein the one or more alkylhydroxybenzonate compound is a mixture of alkylhydroxybenzoate compound having a TBN of 10 to 300 mg KOH/g on an oil-free basis and alkylhydroxybenzoate compound having a TBN of 600 mg KOH/g or greater on an oil-free basis.

19. The lubricating oil composition of claim 15, wherein the molybdenum- containing antioxidant is molybdenum succinimide, molybdenum dithiocarbamate, or trinuclear molybdenum compound.

20. The lubricating oil composition of claim 15, further comprising a friction modifier, viscosity index improver, corrosion inhibitor, or pour point depressant.