Hydraulic Fluid Composition Reducing Synthetic Rubber Swelling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Mineral-based aviation hydraulic fluids using naphthenic base oils often result in excessive swelling of synthetic rubbers, failing specification tests and being limited by supply constraints, while existing alternatives do not adequately address these issues.

Innovation Solution

A functional fluid composition combining 70-99.99% of a base oil composition comprising 50-95% naphthenic base oil and 5-50% Fischer-Tropsch derived base oil, with specific viscosity and flashpoint ranges, to reduce synthetic rubber swelling and enhance thermal stability and evaporation resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If naphthenic base oils are used in hydraulic fluids to meet low temperature properties, then low temperature performance is improved, but synthetic rubber swelling increases excessively

Engineering Contradiction:
Improvelow temperature performanceVSAvoidsynthetic rubber swelling
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the base oil by blending naphthenic base oil with Fischer-Tropsch derived base oil in specific proportions (70-99.99% naphthenic, 0.01-30% Fischer-Tropsch). This parameter modification reduces the swelling effect on synthetic rubbers while preserving the low temperature performance characteristics of naphthenic base oils.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite base oil system by combining two different base oil types (naphthenic and Fischer-Tropsch derived) in controlled ratios. This composite approach allows the hydraulic fluid to benefit from the low temperature properties of naphthenic oils while the Fischer-Tropsch component mitigates the excessive rubber swelling issue.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If naphthenic base oils are used to achieve required viscosity properties, then viscosity specifications are met, but elastomer volume swell exceeds specification limits

Engineering Contradiction:
Improveviscosity stabilityVSAvoidspecification compliance
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent modifies the base oil composition parameters by introducing Fischer-Tropsch derived base oil (0.01-30% by weight) into the naphthenic base oil system. This compositional parameter change maintains the viscosity stability required for hydraulic fluid operation while reducing the elastomer swelling to within specification limits (19-30% for MIL-PRF-5606, 19-28% for MIL-PRF-6083).

Inventive Principle:
Principle #35Parameter changes

3Productivity

If conventional naphthenic base oils are used, then hydraulic fluid functionality is maintained, but product supply is constrained globally

Engineering Contradiction:
Improvehydraulic fluid functionalityVSAvoidnaphthenic base oil availability
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent introduces Fischer-Tropsch derived base oil as an intermediary substance that can partially replace naphthenic base oil in hydraulic fluid formulations. This intermediary component maintains the required hydraulic fluid functionality while reducing dependence on globally constrained naphthenic base oil supplies, thereby ensuring continued product availability.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If Fischer-Tropsch derived base oil replaces portion of naphthenic base oil, then synthetic rubber swelling is reduced, but thermal stability and evaporation resistance are enhanced

Engineering Contradiction:
Improverubber swelling reductionVSAvoidthermal stability improvement
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent utilizes parameter changes in the base oil composition, specifically incorporating 0.01-30% Fischer-Tropsch derived base oil, which fundamentally alters the chemical interaction with synthetic rubbers and thermal degradation behavior. This compositional parameter modification simultaneously achieves swelling reduction and enhanced thermal stability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2424962B1Use of a functional fluid compositions with improved seal swell properties
Publication Date: 2016.12.21 SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ BV

AI summary

A functional fluid composition comprising: (a) from 70% to 99.99%, by weight of the fluid composition, of a base oil composition comprising: (i) from 50% to 95%, by weight of the base oil composition, of a naphthenic base oil; and (ii) from 5% to 50%, by weight of the base oil composition, of a Fischer-Tropsch derived base oil. The functional fluid compositions according to the present invention are suitable for use in hydraulic fluids and shock absorber fluids and are useful for reducing the volume swell of synthetic rubbers.