Low SAPS Lubricating Oil Thermal Oxidation Stability
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Solution Overview
Problem
Low sulphated ash lubricating oil compositions for internal combustion engines face challenges in maintaining thermal oxidative stability and preventing viscosity increase due to thermal oxidation, especially with stringent OEM specifications, while minimizing the use of expensive ashless antioxidants.
Innovation Solution
Incorporating a defined amount of ashless aromatic amine antioxidant in combination with an overbased magnesium detergent, which provides a positive interaction to enhance thermal oxidative stability, allowing for reduced viscosity increase without large amounts of ashless antioxidants, by balancing the concentration of magnesium in the detergent component with the antioxidant in the lubricating oil composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If metal containing lubricant additives are reduced to meet low SAPS requirements, then sulphated ash content is reduced, but thermal oxidative stability deteriorates
Solution Approach 1:
The invention changes the chemical composition parameters by specifying precise ranges for ashless antioxidants (0.5-3.0 mass%) and magnesium detergent (0.03-0.15 mass%), replacing metal-containing additives with a optimized combination of ashless compounds that maintain stability while reducing ash content
Solution Approach 2:
The invention creates a composite additive system combining ashless aromatic amine antioxidants with ashless magnesium detergents, where the synergistic interaction between these components provides both low ash content and improved thermal oxidative stability
2Reliability
If ashless antioxidants are increased to improve thermal oxidative stability, then stability is improved, but cost increases
Solution Approach 1:
The invention optimizes the concentration parameter of ashless antioxidants to a specific range (0.5-3.0 mass%), achieving effective thermal oxidative stability at lower concentrations through the synergistic effect with magnesium detergent, thereby reducing overall additive package cost
Solution Approach 2:
The ashless magnesium detergent acts as an intermediary component that enhances the effectiveness of ashless antioxidants, allowing lower antioxidant concentrations to achieve the same stability level, thus reducing material costs
3Duration of action of stationary object
If sulphated ash content is reduced to protect after-treatment devices, then device service life is extended, but viscosity increase due to thermal oxidation worsens
Solution Approach 1:
The invention changes the chemical composition by reducing sulphated ash to below 0.6 mass% while simultaneously optimizing the ashless antioxidant and magnesium detergent concentrations to maintain viscosity stability, protecting after-treatment devices without sacrificing oil performance
Solution Approach 2:
The invention converts the potential harm of low ash content (reduced thermal stability) into a benefit by using the synergistic combination of ashless antioxidants and magnesium detergent, which provides both low ash content and improved viscosity stability under thermal oxidation conditions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively improves thermal oxidative stability and reduces viscosity increase in low sulphated ash lubricating oils, meeting stringent OEM requirements such as the Renault Catalyst Oxidation Test, without the need for substantial ashless antioxidants.
Implementation Method 1
improve the thermal oxidative stability of the lubricating oil composition and controlling/inhibiting an increase in viscosity of the lubricating oil composition due to the thermal oxidation of the lubricating oil composition
Implementation Method 2
exhibit improved thermal oxidative stability and reduced levels of oil thickening due to thermal oxidation of the lubricant
Data Source
AI summary
A low sulphated ash lubricating oil composition comprises an ashless aromatic amine antioxidant and an overbased magnesium detergent which exhibits improved thermal oxidation stability.