EVOH Copolymer Composition for Long-Run Degradation Resistance

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Solution Overview

Problem

EVOH resin compositions face degradation issues due to thermal and environmental factors, leading to reduced melt stability, odor emission, and cracking, which existing stabilizers and antioxidants cannot adequately address.

Innovation Solution

Incorporating a very small amount of an iron compound (0.01 to 20 ppm) in combination with an antioxidant (1 to 30,000 ppm) improves the degradation resistance of EVOH resin compositions, enhancing their long-run formability and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If various heat stabilizers are added to the EVOH resin, then thermal degradation is suppressed, but the degradation resistance under prolonged exposure to oxygen and environmental factors remains insufficient

Engineering Contradiction:
Improvethermal stabilityVSAvoiddegradation resistance
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent combines multiple stabilizer components (heat stabilizer, antioxidant, and UV stabilizer) into a composite stabilization system. This composite approach addresses both thermal degradation during processing and long-term environmental degradation, resolving the contradiction between thermal stability and overall degradation resistance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent merges multiple stabilization functions into a single composition system where heat stabilizers, antioxidants, and UV stabilizers work synergistically. This combining of multiple protective mechanisms provides comprehensive degradation resistance that neither single stabilizer type could achieve alone.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a specific amount of antioxidant and conjugated polyene compound are used, then degradation by oxygen is suppressed, but odor emanation and cracking still occur under prolonged use

Engineering Contradiction:
Improveoxidation resistanceVSAvoidodor emanation and cracking
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent employs a composite stabilization system combining antioxidants with UV stabilizers and heat stabilizers. This multi-component composite prevents oxidation-related cracking and odor emanation by providing comprehensive protection against multiple degradation pathways simultaneously.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the concentration ranges of multiple stabilizer components to achieve synergistic effects. By carefully controlling the parameters of each stabilizer type and their combinations, the system prevents harmful degradation products while maintaining long-term reliability.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If hindered amine compound is blended with EVOH resin, then weatherability is improved, but degradation resistance under combined thermal and environmental exposure remains insufficient

Engineering Contradiction:
ImproveweatherabilityVSAvoidcomprehensive degradation resistance
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The patent creates a composite stabilization system that integrates UV stabilizers (hindered amine compounds) with heat stabilizers and antioxidants. This composite formulation provides comprehensive degradation resistance under combined thermal and environmental exposure, surpassing the performance of single stabilizer types.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The stabilization composition is designed to provide multiple protective functions simultaneously: UV protection, thermal stability, and oxidation resistance. This multi-functional stabilization system addresses various degradation mechanisms that occur during prolonged outdoor use.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 combination significantly enhances the degradation resistance and formability of EVOH resin compositions, making them suitable for prolonged use in various packaging and multilayer pipe applications without significant degradation or cracking.

Implementation Method 1

the combinational use of a specific very small amount of the iron compound and the antioxidant improves the degradation resistance of the EVOH resin composition

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

an antioxidant... is present in an amount of 1 to 30,000 ppm based on the weight of the EVOH resin composition

Methodology Applied
Scientific EffectAntioxidant action:

Data Source

PatentUS11535723B2Ethylene-vinyl alcohol copolymer composition, pellets, multilayer structure, and multilayer pipe
Publication Date: 2022.12.27 MITSUBISHI CHEM CORP

AI summary

An ethylene-vinyl alcohol copolymer composition contains: (A) an ethylene-vinyl alcohol copolymer; (B) an antioxidant; and (C) an iron compound; wherein the iron compound (C) is present in an amount of 0.01 to 20 ppm on a metal basis based on the weight of the ethylene-vinyl alcohol copolymer composition. The ethylene-vinyl alcohol copolymer composition is excellent in degradation resistance.