Polyester Film Antioxidant Composition for Repetitive Heat Durability

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Solution Overview

Problem

Polyester films used in automotive components, such as flexible flat cables, face limitations in high-temperature stability and durability, leading to issues like color change and fracture when exposed to repetitive heat, due to insufficient oxidation stability and thermal stabilizer degradation.

Innovation Solution

A polyester resin composition incorporating a diol residue with cyclohexanedimethanol and dicarboxylic acid residues, along with a combination of phenol-based, phosphorus-based, and sulfur-based antioxidants, is developed to enhance oxidation stability and durability, including a residual catalyst like titanium, which is applied during film manufacturing to prevent thermal oxidation and improve heat resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional polyester films are used in high-temperature applications, then they provide basic functional performance, but they exhibit poor oxidation stability and durability leading to color change and fracture

Engineering Contradiction:
Improveoxidation stabilityVSAvoidthermal oxidation damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies composite materials by combining multiple antioxidant types (phenol-based, phosphorus-based, and sulfur-based antioxidants) with specific polyester resin compositions containing cyclohexanedimethanol and dicarboxylic acid residues. This multi-component antioxidant system works synergistically to provide comprehensive protection against thermal oxidation, thereby improving oxidation stability and durability while preventing color change and fracture in high-temperature applications.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs parameter changes by optimizing the specific composition ratios of dicarboxylic acid residues (isophthalic acid and terephthalic acid) and diol residues (cyclohexanedimethanol), along with precise formulation of antioxidant concentrations. These compositional parameter adjustments enhance the polyester film's resistance to thermal oxidation, improving reliability under high-temperature conditions without sacrificing other functional properties.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If polyester films are exposed to repetitive heat, then they undergo thermal degradation, but adding thermal stabilizers leads to stabilizer degradation over time

Engineering Contradiction:
Improveheat resistanceVSAvoiddurability
Core Design Contradiction:
TemperatureVSDuration of action of stationary object

Solution Approach 1:

The patent applies preliminary action by incorporating a comprehensive antioxidant system into the polyester film formulation before the film is subjected to thermal stress. The phenol-based, phosphorus-based, and sulfur-based antioxidants are pre-added to the resin composition to provide proactive protection against thermal degradation. This preventive approach allows the film to maintain its heat resistance and structural integrity over extended periods of repetitive heating without experiencing stabilizer depletion or degradation.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If antioxidants are added to improve durability, then oxidation stability improves, but the complexity of the resin composition increases

Engineering Contradiction:
ImprovedurabilityVSAvoidresin composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent manages composition complexity through parameter changes by defining specific ranges and ratios for the multiple components. The dicarboxylic acid residue composition (isophthalic acid and terephthalic acid), diol residue composition (cyclohexanedimethanol), and antioxidant concentrations are all specified with precise parameters. This structured parameter definition allows for optimized durability while maintaining manufacturability and controlling the complexity of the overall resin composition.

Inventive Principle:
Principle #35Parameter changes

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 solution results in a polyester film with improved heat resistance and durability, as evidenced by a low durability index and minimal yellow index variation, effectively preventing fracture and maintaining intrinsic viscosity, making it suitable for high-temperature applications in electronic devices like flexible flat cables.

Implementation Method 1

the antioxidant includes a phenol-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant

Methodology Applied
Scientific EffectRadical scavenging: Oxidation

Implementation Method 2

the phosphorus-based antioxidant and the sulfur-based antioxidant may be included in a weight ratio of 1:0.1 to 4

Methodology Applied
Scientific EffectThermal stabilization:

Implementation Method 3

The sulfur-based antioxidant may be included in an amount of 30 parts by weight or more based on 100 parts by weight of the phenol-based antioxidant

Methodology Applied
Scientific EffectSynergistic antioxidant action: Oxidation

Data Source

PatentUS12173117B2Polyester resin composition, polyester film, and laminate for electronic device
Publication Date: 2024.12.24 MICROWORKS CO LTD

AI summary

The present disclosure relates to a polyester resin composition including a polyester resin including a diol residue and a dicarboxylic acid residue, wherein the diol residue includes a cyclohexanedimethanol residue and the dicarboxylic acid residue includes an isophthalic acid residue and a terephthalic acid residue, wherein an amount of the isophthalic acid residue is 0 to 20 mol % when a total amount of the dicarboxylic acid residue is considered as 100 mol %, wherein an amount of the cyclohexanedimethanol residue is 50 to 100 mol % when a total amount of the diol residue is considered as 100 mol %, wherein the polyester resin composition includes an antioxidant, and wherein the antioxidant includes a phenol-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant.