Polyetherimide Films via Extrusion for High-Temperature Capacitors

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Solution Overview

Problem

There is a need for high-purity, high-breakdown-strength, and high-dielectric-constant polyetherimide films suitable for high-temperature applications, with efficient industrial-scale production methods that are environmentally friendly, as existing films like BOPP and PET have limitations in energy density and operating temperature, and solvent-casting processes are costly and wasteful.

Innovation Solution

Polyetherimide films are manufactured through extrusion using a specific polymerization of aromatic dianhydrides with meta-phenylene or para-phenylene diamines, endcapped with aromatic primary monoamines, resulting in high yield, high-purity films with improved dielectric properties and thermal stability, and are produced in a solventless process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If solvent-casting process is used to manufacture polyetherimide films, then dielectric constant and operating temperature are improved, but manufacturing cost increases and solvent residue problems occur

Engineering Contradiction:

Improveoperating temperatureVSAvoidmanufacturing cost

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent changes the manufacturing process parameters from solvent-casting to extrusion processing. This parameter change eliminates the need for solvents while maintaining the high dielectric constant (≥3.0) and high operating temperature (≥200°C) properties of polyetherimide films, thereby reducing manufacturing cost and avoiding solvent residue issues.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If extrusion process is used to manufacture polyetherimide films, then manufacturing efficiency is improved, but film purity and quality are compromised

Engineering Contradiction:

Improvemanufacturing efficiencyVSAvoidfilm purity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by pre-drying the polyetherimide material to remove moisture and pre-filtering the melt through filters before extrusion. These preliminary actions ensure that the extrusion process produces high-purity films with excellent electrical properties, maintaining film purity ≥99% while achieving high manufacturing efficiency.

Inventive Principle:

Principle #10Preliminary action

3Quantity of substance

If film thickness is reduced to maximize energy storage, then volumetric energy density is improved, but breakdown strength requirements become more stringent

Engineering Contradiction:

Improveenergy storage capacityVSAvoidbreakdown strength

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the material parameters by using extrusion-processed polyetherimide with optimized molecular weight distribution and reduced impurities. This parameter change enables the film to achieve high breakdown strength (≥300 V/μm) even at reduced thickness, thereby maximizing volumetric energy density while maintaining reliability.

Inventive Principle:

Principle #35Parameter changes

4Manufacturing precision

If polyetherimide content before extrusion is increased to improve film quality, then dielectric properties are enhanced, but processing difficulty increases

Engineering Contradiction:

Improvedielectric propertiesVSAvoidprocessing difficulty

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-drying the polyetherimide material to remove moisture and pre-mixing with lubricants and stabilizers before extrusion. These preliminary actions reduce processing difficulty by preventing moisture-related defects and improving melt flow characteristics, enabling high dielectric properties to be achieved with standard extrusion equipment.

Inventive Principle:

Principle #10Preliminary action

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 extruded polyetherimide films achieve high yield, with at least 90% of the polyetherimide content before extrusion, exhibiting enhanced dielectric constants, breakdown strength, and thermal stability, enabling high-energy density capacitors that operate effectively at elevated temperatures without the environmental and cost issues of solvent-casting.

Implementation Method 1

When a voltage is applied across the plates, the electric field on the dielectric displaces electric charges, and thus stores energy

Methodology Applied

Scientific EffectDielectric displacement: Dielectric

Implementation Method 2

extrusion has been proposed for the manufacture of polyetherimide films

Methodology Applied

Scientific EffectExtrusion: Extrusion

Data Source

PatentUS10077345B2Capacitor films, methods of manufacture, and articles manufactured therefrom

Publication Date: 2018.09.18 SHPP GLOBAL TECH BV

AI summary

A polyetherimide film comprising a fluoropolymer and an extruded polyetherimide comprising units derived from polymerization of an aromatic dianhydride with a diamine selected from a meta-phenylene diamine, a para-phenylene diamine, and a combination thereof, wherein the polyetherimide is endcapped with an a substituted or unsubstituted aromatic primary monoamine; and wherein the polyetherimide film comprises at least 90 weight % of the polyetherimide before extrusion.