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SYNERGISTIC 3-WAY OXIDATION INHIBITOR SYSTEM FOR PASSENGER CAR MOTOR OILS

IP.com Disclosure Number: IPCOM000010544D
Publication Date: 2002-Dec-13

Publishing Venue

The IP.com Prior Art Database

Related People

Roby, S.H.: INVENTOR [+3]

Related Documents

IPCOM000010189D: IP.COM [+3]

Abstract

The API SL/ILSAC GF-3 passenger car engine oil category places a premium on oxidative oil thickening. In particular, the Sequence IIIF engine dynamometer test is specifically designed to severely stress engine oils under high-speed, high-load conditions for 80 hours of continuous operation.

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Synergistic 3-Way Oxidation Inhibitor System For Passenger Car Motor Oils

Abstract of the Disclosure

The API SL/ILSAC GF-3 passenger car engine oil category places a premium on oxidative oil thickening.  In particular, the Sequence IIIF engine dynamometer test is specifically designed to severely stress engine oils under high-speed, high-load conditions for 80 hours of continuous operation. 

Oxidation control has proven to be a significant challenge.  Traditional oxidation inhibitors or inhibitor combinations are often ineffective in the Sequence IIIF.  Our work has shown that a 3-way combination of molybdenum/nitrogen-containing complexes, a sulfurized ester olefin, and a nitrogen-containing ashless antioxidant effectively controls Sequence IIIF oxidative thickening.

Summary of the Invention

The present invention is related to a lubricating oil composition for internal combustion engines.  More particularly, the lubricating oil composition of the present invention is directed to a synergistic combination of molybdenum/nitrogen-containing complexes, a sulfurized ester olefin, and a nitrogen-containing ashless antioxidant that effectively controls Sequence IIIF oxidative thickening and a method of employing such.

In its broadest embodiment, the lubricating oil composition of the present invention comprises:

a)                 a major amount of a base oil of lubricating viscosity; and

b)                 a minor, but effective amount to control Sequence IIIF oxidative thickening, of:

i)                    a molybdenum/nitrogen-containing complexes;

ii)                  a sulfurized ester olefin, and

iii)                a nitrogen-containing ashless antioxidant.

Among other factors, it will be understood that this invention is not based on the discovery of any one of the disclosed components as new compositions of matter or their individual usefulness as additive agents in lubricant oil compositions.  Rather the lubricating oil composition of the present invention is based on the surprising discovery that a lubricating oil composition comprising the above aforementioned embodiment is useful for the severe service function required by the API SL/ILSAC GF-3 passenger car engine oil category and improves Sequence IIIF oxidative thickening.  The present lubricating oil composition exhibits a synergistic reduction in oxidative thickening and accordingly is useful for reducing oxidative thickening when employed in a lubricating oil.  Therefore, another aspect of the present invention is directed to a method for improving oxidative thickening in an internal combustion engine by operating such an engine with the lubricating oil composition of the present invention.

detailed description of the invention

The Sequence III test has been completely redesigned for API SL/ILSAC GF-3 as the Sequence IIIF.  The new API SL/ILSAC GF-3 passenger car engine oil category places a premium on oxidative oil thickening.  In particular, the Sequence IIIF engine dynamometer test is specifically designed to severely stress engine oils under high-speed, hi...