Polyimide Film Composition for Lower-Temperature Graphite Sheets

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing polyimide films for graphite sheets require high temperatures for graphitization, leading to high fabrication costs and energy consumption, while there is a need for a film that can provide good thermal conductivity while reducing these costs.

Innovation Solution

A polyimide film is fabricated by imidizing a polyamic acid formed from a reaction between dianhydride and diamine monomers in the presence of metal compound particles with an average diameter of 1 μm to 6 μm, which allows for graphitization at lower temperatures and enhances thermal conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If graphitization is performed at high temperatures (2800°C or higher), then thermal conductivity is improved, but power consumption increases and fabrication costs increase

Engineering Contradiction:
Improvegraphitization temperatureVSAvoidpower consumption
Core Design Contradiction:
TemperatureVSUse of energy by stationary object

Solution Approach 1:

The patent changes the chemical composition parameter of the polyimide film by incorporating specific heterocyclic ring structures (triazine, pyrimidine, pyridine rings) formed from cyanurate triesters. This chemical parameter change enables the material to undergo graphitization at lower temperatures (below 2800°C) while maintaining good thermal conductivity, thus reducing power consumption without sacrificing thermal performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polyimide structure by combining cyanurate triesters with diamine monomers to form polyimides containing heterocyclic rings. This composite molecular structure integrates the benefits of both components: the cyanurate-derived heterocyclic rings facilitate low-temperature graphitization, while the diamine component maintains the polyimide's mechanical and thermal stability, achieving both energy efficiency and performance

Inventive Principle:
Principle #40Composite materials

2Temperature

If graphitization is performed at high temperatures (2800°C or higher), then thermal conductivity is improved, but fabrication costs increase

Engineering Contradiction:
Improvegraphitization temperatureVSAvoidfabrication cost
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent modifies the chemical structure parameter of the polyimide by introducing heterocyclic rings from cyanurate triesters, which fundamentally changes the graphitization behavior. This parameter change allows graphitization to occur at lower temperatures, directly reducing fabrication costs associated with high-temperature processing equipment and energy consumption while maintaining manufacturing feasibility

Inventive Principle:
Principle #35Parameter changes

3Temperature

If metal compound particles are added to enhance thermal conductivity, then thermal conductivity increases, but fabrication complexity increases

Engineering Contradiction:
Improvethermal conductivityVSAvoidfabrication process complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The heterocyclic ring structures formed from cyanurate triesters act as an intermediary mechanism that enables thermal conduction enhancement without requiring discrete metal compound particles. The heterocyclic rings create efficient heat transfer pathways within the polyimide matrix through their molecular structure, achieving thermal conductivity improvement while avoiding the fabrication complexity of dispersing and integrating metal particles

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical approach of adding metal compound particles with a chemical approach using heterocyclic ring structures. This substitution eliminates the need for particle dispersion, interface bonding, and related complex fabrication steps, while achieving thermal conductivity enhancement through the intrinsic thermal properties of the heterocyclic molecular structure

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 polyimide film, when graphitized at lower temperatures, achieves thermal conductivity 1.05 to 1.6 times higher than films without metal compound particles, reducing fabrication costs and improving thermal performance.

Implementation Method 1

The polyimide film is fabricated by imidizing a polyamic acid formed by reaction between a dianhydride monomer and a diamine monomer

Methodology Applied
Scientific EffectImidization reaction: Chemical Bonding

Implementation Method 2

the reaction is carried out in the presence of particles of a metal compound having an average particle diameter (D50) of about 1 μm to about 6 μm... achieves thermal conductivity 1.05 to 1.6 times higher than films without metal compound particles

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

Fabrication of a graphite sheet through graphitization of a polyimide film generally requires high temperatures of 2,800° C. or higher... allows for graphitization at lower temperatures

Methodology Applied
Scientific EffectGraphitization: Phase Change

Data Source

PatentUS12509554B2Polyimide film for graphite sheet, manufacturing method therefor, and graphite sheet manufactured therefrom
Publication Date: 2025.12.30 PI ADVANCED MATERIALS CO LTD

AI summary

Disclosed herein are a polyimide film for graphite sheets, a method of fabricating the same, and a graphite sheet fabricated using the same. The polyimide film is fabricated by imidizing a polyamic acid formed by reaction between a dianhydride monomer and a diamine monomer, wherein the reaction is carried out in the presence of particles of a metal compound having an average particle diameter (D50) of about 1 μm to about 6 μm.