Nitrogen-Modified Polyacrylate Viscosity Modifiers for Fluoroelastomer Seal Compatibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lubricant compositions containing nitrogen-containing poly(meth)acrylate ester viscosity modifiers often degrade fluoroelastomer seals, leading to compatibility issues, increased maintenance costs, and equipment damage due to seal failure.
Innovation Solution
A lubricant composition comprising an oil of lubricating viscosity, a poly(meth)acrylate ester polymer with 50 to 99.5 weight percent ester monomer units and 0.5 to 5 weight percent amine nitrogen-containing dispersant monomer units, along with an esterified copolymer having a backbone derived from an α-olefin monomer and ethylenically unsaturated carboxylic acid or anhydride, which includes nitrogen functionality in pendant groups attached through ester, amide, or imide linkages, improving seal compatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nitrogen-containing poly(meth)acrylate ester viscosity modifiers are used to improve viscosity index and dispersancy performance, then viscosity index and dispersancy are improved, but fluoroelastomer seal compatibility deteriorates
Solution Approach 1:
The patent applies parameter changes by carefully controlling the nitrogen content in the poly(meth)acrylate ester viscosity modifier within the range of 0.01 to 1.0 weight percent, and by limiting the amine nitrogen-containing dispersant monomer units to 0.5 to 5 weight percent of the polymer. This precise parameter control maintains effective dispersancy and viscosity index improvement while reducing the harmful effect on fluoroelastomer seals.
Solution Approach 2:
The patent uses composite materials by combining poly(meth)acrylate ester viscosity modifiers with specific esterified copolymers containing nitrogen functionality in pendant groups. This composite approach creates a lubricant composition that achieves both good dispersancy performance and seal compatibility through the synergistic effect of the different polymer components.
2Reliability
If amine nitrogen-containing dispersant monomer units are incorporated into poly(meth)acrylate ester polymers to enhance dispersancy, then dispersant functionality is improved, but seal degradation increases
Solution Approach 1:
The patent applies parameter changes by optimizing the concentration of amine nitrogen-containing dispersant monomer units to be 0.5 to 5 weight percent of the polymer, contributing 25 to 150 parts per million of nitrogen to the lubricant. This controlled parameter adjustment maintains effective dispersant functionality while minimizing seal degradation.
Solution Approach 2:
The patent applies local quality by positioning the nitrogen functionality specifically in pendant groups (such as pendant ester or amide groups containing nitrogen functionality) rather than in the main polymer chain. This localized placement of nitrogen functionality enhances dispersant effectiveness at the molecular level while reducing the overall harmful impact on seals.
Data Source
AI summary
A lubricant composition of (a) an oil of lubricating viscosity; (b) a poly(meth)acrylate ester polymer comprising 0.5 to 5 weight percent of amine nitrogen-containing dispersant monomer units and (c) an esterified copolymer with a backbone comprising units derived from (i) an α-olefin monomer of at least about 6 carbon atoms, (ii) an ethylenically unsaturated carboxylic acid or derivative thereof, further containing nitrogen functionality in groups pendant from the copolymer backbone, provides a good combination of seal performance and oxidation resistance.