Polyester Base Fluids for Gear Oil Compatibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High viscosity base fluids, such as polyalphaolefins, face challenges with low polarity, leading to poor compatibility with dispersion inhibitors and crystallinity issues, which affect their performance in gear oils under high mechanical stress and varying temperatures.
Innovation Solution
The use of polyesters derived from internal epoxides, which exhibit low polymer crystallinity and improved oil compatibility due to shorter side-chains and increased branching, allowing for the development of lubricant formulations with enhanced shear stability and temperature range performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If high viscosity polyalphaolefins (PAOs) are used as base fluids, then low temperature performance is improved, but polarity is reduced leading to poor compatibility with dispersion inhibitors
Solution Approach 1:
The patent applies composite materials by combining PAO base oil with polar additives (ester-functionalized monomers, polyvinylethers, or copolymers with maleates/alkyl acrylates/alkyl methacrylates) to create a composite base fluid system. This composite structure provides both the low temperature performance of PAO and the polarity needed for dispersion inhibitor compatibility, resolving the contradiction between these two properties.
Solution Approach 2:
The patent changes the polarity parameter of the base fluid by introducing polar functional groups through copolymerization or ester-functionalization. This parameter change allows the base fluid to maintain its low temperature performance while gaining the polarity required for compatibility with dispersion inhibitors and other polar lubricant additives.
2Stability of the object's composition
If polar low viscous fluids are used to increase polarity, then compatibility with dispersion inhibitors is improved, but problems with coatings and seals arise
Solution Approach 1:
The patent changes the viscosity parameter by using high viscosity polar base fluids (KV100 of 30-1000 cSt) instead of low viscous polar fluids. This parameter change maintains the polarity needed for dispersion inhibitor compatibility while reducing the harmful effects on coatings and seals that occur with low viscosity polar fluids.
3Stability of the object's composition
If polyesters made from dimer acids are used, then oil compatibility is improved, but performance in lubricants is reduced due to cyclic structures
Solution Approach 1:
The patent extracts the harmful cyclic structure from the polyester molecule by using linear diacids and diols instead of dimer acid-derived cyclic structures. This extraction removes the source of poor lubricant performance while maintaining the oil compatibility benefits of polyester structures, allowing the use of linear polyesters with both good solubility and lubricant performance.
Data Source
AI summary
A polyester is useful as a high viscosity base fluid. A method for its preparation involves isomerizing an alpha-olefin, epoxidizing an internal olefin, reacting an internal epoxide, and isolating the polyester. Lubricant compositions can contain such polyesters and the compositions are useful as automatic transmission fluids, manual transmission fluids, continuously variable transmission fluids, gear oil formulations, industrial gear oil formulations, axle fluid formulations, dual clutch transmission fluids, dedicated hybrid transmission fluids, or as hydraulic oils.