Magnet Wire Insulation Composition for Low Permittivity at High Heat

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Solution Overview

Problem

Current polymeric insulating compositions for magnet wires are inadequate at elevated temperatures, as their relative permittivity increases with temperature, leading to inefficient insulation, and existing compositions do not provide sufficient insulation integrity above 150°C.

Innovation Solution

A composition comprising a mixture of polyaryletherketone and polyetherimide with a weight ratio of 95:5 to 55:45, which maintains low relative permittivity at high temperatures, specifically designed for use between 160°C and 250°C, incorporating additional thermoplastics, fillers, or additives to enhance thermal stability and mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If polymeric insulating compositions are used at elevated temperatures, then electrical insulation is provided, but the relative permittivity increases with temperature leading to inefficient insulation

Engineering Contradiction:
Improvetemperature rangeVSAvoidinsulation efficiency
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies composite materials by combining polyaryletherketone (PAEK) and polyetherimide (PEI) in specific weight ratios (60:40 to 90:10) to create a synergistic composition. The PAEK provides thermal stability and low permittivity at high temperatures, while the PEI enhances mechanical properties and processability. This composite approach resolves the contradiction by maintaining insulation efficiency (low permittivity) across elevated temperature ranges that neither polymer could achieve alone.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies parameter changes by optimizing the weight ratio of PAEK to PEI within specific ranges (60:40 to 90:10) and controlling processing parameters such as melt mixing temperature and cooling rate. By adjusting these parameters, the composition achieves a balance between maintaining low relative permittivity at high temperatures and ensuring adequate mechanical properties, thus resolving the temperature-insulation efficiency contradiction.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If existing polymeric compositions are used above 150°C, then insulation is provided, but insulation integrity is insufficient

Engineering Contradiction:
Improveoperating temperatureVSAvoidinsulation integrity
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent uses composite materials combining PAEK and PEI where the PAEK component (60-90 wt%) provides exceptional thermal stability and maintains insulation integrity at temperatures above 150°C, while the PEI component (10-40 wt%) reinforces mechanical strength and prevents degradation. This composite structure ensures both high-temperature operation and maintained insulation integrity, resolving the contradiction between operating temperature and insulation reliability.

Inventive Principle:
Principle #40Composite materials

3Length of stationary object

If insulation thickness is reduced to meet design requirements, then device complexity is reduced, but insulation efficiency decreases at high temperatures

Engineering Contradiction:
Improveinsulation thicknessVSAvoidinsulation efficiency
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The patent applies composite materials with PAEK as the primary component (60-90 wt%) which inherently possesses low relative permittivity and excellent electrical insulation properties. This allows the use of thinner insulation layers while maintaining or improving insulation efficiency at high temperatures, thus reducing device complexity without compromising reliability. The superior performance of the PAEK-PEI composite enables thinner designs compared to conventional polymers.

Inventive Principle:
Principle #40Composite materials

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 composition exhibits improved insulation efficiency at elevated temperatures, with a lower relative permittivity compared to compositions made solely of polyaryletherketone, allowing for effective electrical insulation up to 250°C with reduced thickness requirements, thus addressing the inefficiencies of existing materials.

Implementation Method 1

The relative permittivity, also called sometimes dielectric constant, is the permittivity of a material expressed as a ratio with the electric permittivity of vacuum. By definition, the permittivity of vacuum is set to 1. The relative permittivity is linked to the polarizability of atoms/polymeric chains in a material.

Methodology Applied
Scientific EffectDielectric permittivity: Dielectric Permittivity

Data Source

PatentEP4293688A1Use of a composition having low permittivity over a high temperature range
Publication Date: 2023.12.20 ARKEMA FRANCE SA
  • EP4293688A1 patent drawingFigure 1~2
  • EP4293688A1 patent drawingFigure 3~4
  • EP4293688A1 patent drawingFigure 5

AI summary

The present application deals with the use of an insulating composition as an electrical insulation material at a temperature of more than 160°C, wherein the insulating composition comprises at least one polyaryletherketone and at least one polyetherimide, the weight ratio of the polyaryletherketone to the polyetherimide being of 95:5 to 55:45, and a process wherein such an insulating composition is used, the process including letting an electrical current going through said electrical wire at a temperature of 160°C or more