Lubricating Oil Composition with Low Phosphorus Anti-Wear Additives
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lubricating oil compositions face challenges in achieving excellent wear resistance and high friction coefficient in internal combustion engines while reducing phosphorus content to prevent exhaust gas catalyst poisoning, especially with stringent environmental regulations.
Innovation Solution
A lubricating oil composition containing a base oil, an imide compound, a metal-based detergent, and a zinc thiophosphate, with specific structural formulations and content ratios, including a succinic acid monoimide or bisimide, metal sulfonate or phenate, and zinc dithiophosphate, where the phosphorus content from the zinc dithiophosphate is limited to less than 800 ppm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phosphorus-containing anti-wear agents (such as zinc dithiophosphate) are added to improve wear resistance, then wear resistance is improved, but phosphorus content increases causing exhaust gas catalyst poisoning
Solution Approach 1:
The patent changes the chemical structure parameters of the anti-wear agent from conventional zinc dithiophosphate to zinc thiophosphate with specific alkyl group configurations. This structural modification reduces phosphorus content while maintaining anti-wear performance, directly resolving the contradiction between wear resistance and catalyst protection
Solution Approach 2:
The patent employs a composite additive system combining zinc thiophosphate with specific dispersants and friction modifiers. This composite approach allows the lubricating oil to achieve wear protection through multiple mechanisms rather than relying solely on phosphorus-containing compounds, thereby reducing catalyst poisoning while maintaining reliability
2Object-affected harmful factors
If phosphorus content is reduced to prevent catalyst poisoning, then environmental compatibility is improved, but wear resistance deteriorates
Solution Approach 1:
The patent modifies the anti-wear agent structure by replacing phosphorus with sulfur-based zinc thiophosphate compounds having specific molecular weight ranges for alkyl groups. This parameter change enables low phosphorus content while preserving anti-wear functionality through optimized molecular structure
Solution Approach 2:
The patent introduces zinc thiophosphate as an intermediary substance that can provide wear protection through alternative chemical mechanisms not dependent on phosphorus. The zinc thiophosphate acts as a mediator between the lubricating oil and metal surfaces, forming protective films through sulfur-based chemistry rather than phosphorus-based chemistry
3Force
If friction coefficient is increased to improve clutch capacity, then clutch performance is improved, but wear resistance may deteriorate
Solution Approach 1:
The patent applies different functional characteristics to different components of the lubricating oil system. The zinc thiophosphate provides extreme pressure protection and wear resistance through boundary lubrication mechanisms, while the friction modifiers selectively increase friction coefficient in the clutch region. This local differentiation allows simultaneous optimization of clutch capacity and wear resistance
Solution Approach 2:
The patent uses a composite additive package that combines friction modifiers with the zinc thiophosphate-based anti-wear system. This composite formulation enables the lubricating oil to exhibit dual functionality: high friction coefficient for clutch engagement and effective wear protection for engine components, resolving the contradiction between these two performance requirements
Data Source
AI summary
The present invention relates to a lubricating oil composition to be used for internal combustion engines, the lubricating oil composition containing a base oil (A), an imide compound (B) that is at least one selected from a succinic acid monoimide (B1) represented by the general formula (b-1) and a succinic acid bisimide (B2) represented by the foregoing general formula (b-2), a metal-based detergent (C) that is at least one selected from a metal sulfonate (C1) having a branched alkyl group and a metal phenate (C2) having a branched alkyl group, and a zinc dithiophosphate (D), wherein the content of a phosphorus atom derived from the component (D) is less than 800 ppm by mass on the basis of the total amount of the lubricating oil composition; and a method for producing the same. The present invention is able to provide a lubricating oil composition in which even in the case where the content of a phosphorus atom derived from an anti-wear agent is reduced, it is possible to reveal excellent wear resistance in an internal combustion engine and a high friction coefficient in a wet clutch; and a method for producing the same.