Copper-Organoligand Complexes for Polyamide Stabilization

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Solution Overview

Problem

Current copper stabilizers for polyamides, which contain high levels of halogen salts, lead to hygroscopic deposits and corrosion issues, compromising tracking resistance and filament breakage during fiber production, while also reagglomerating during processing, thus failing to meet the requirements of the automotive and electronics industries.

Innovation Solution

The development of low-halogen, stoichiometrically defined copper salt-organoligand complexes using 2-oxazoline derivatives as ligands, which form stable and air-stable complexes without additional halides, providing improved thermal stability and functional properties such as antibacterial and light-absorbing capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional copper stabilizers with high levels of halogen salts are used to stabilize polyamides against thermal degradation, then thermal stability is improved, but hygroscopic deposits form and corrosion issues occur, compromising tracking resistance and causing filament breakage

Engineering Contradiction:
Improvethermal stabilityVSAvoidhygroscopic deposits and corrosion
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and removes the harmful halogen salts from the stabilizer system while retaining the essential copper-based stabilization mechanism. By using copper complexes with organic ligands (such as salen ligands, porphyrins, or other chelating agents) instead of halogen salts, the patent eliminates the source of hygroscopic deposits and corrosion problems while maintaining thermal stability functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the chemical composition parameters of the stabilizer system by replacing inorganic halogen salts with organic chelating ligands. This parameter change transforms the stabilizer from a halogen-based system to an organic complex-based system, fundamentally altering the chemical behavior to eliminate deposit formation and corrosion while preserving thermal stabilization capability.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If copper stabilizers with additional halides are used to achieve effective stabilization, then thermal stability is improved, but reagglomeration occurs during processing

Engineering Contradiction:
Improvethermal stabilityVSAvoidreagglomeration during processing
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The invention segments the stabilizer system into distinct functional components: a copper center for stabilization and separate organic chelating ligands for dispersion control. This segmentation allows the ligands to act as steric barriers that prevent copper particle reagglomeration during processing while the copper center provides thermal stabilization, resolving the contradiction between stabilization effectiveness and compositional stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The organic chelating ligands serve as intermediary molecules that mediate between the copper stabilizer and the polyamide matrix. These ligands coordinate to copper ions to form stable complexes that remain uniformly dispersed in the polymer, preventing direct copper-copper interactions that would lead to reagglomeration while maintaining the copper's thermal stabilization function.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If high concentrations of halogen (up to 3000 ppm) are introduced to achieve adequate stabilization, then thermal stability is improved, but tracking resistance is compromised to the point of failure

Engineering Contradiction:
Improvethermal stabilityVSAvoidtracking resistance
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The invention converts the traditionally harmful role of halogen into a beneficial or neutral role by eliminating the need for high halogen concentrations. The copper complexes with organic ligands provide stabilization through alternative mechanisms (such as radical scavenging or metal-catalyzed degradation prevention) that do not involve halogen release, thereby maintaining thermal stability while preserving tracking resistance.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

These complexes enhance the thermal stability of polyamides, prevent reagglomeration, and maintain mechanical properties, allowing for higher continuous service temperatures and the incorporation of functional properties like antibacterial effects and radiation absorption without the drawbacks of traditional copper stabilizers.

Implementation Method 1

The metal salt-organoligand complex compounds consist of a combination of a metal salt with a heterocyclic organic compound, which acts as a ligand to the metal ion and leads to a stoichiometric, thermally stable complex compound

Methodology Applied
Scientific EffectCoordination chemistry:

Implementation Method 2

The organoligand is a 2-oxazoline derivative. The metal salt is a copper(I) or copper(II) acetate or a zinc(II), tin(II), cobalt-molybdenum, titanium, silver(I), halide, nitrate, phosphate or acetate

Methodology Applied
Scientific EffectChelation:

Data Source

PatentEP2640776B1Polyamide compositions with improved thermo-oxidative, Anti-bacterial, light- or energy active properties and method for producing same
Publication Date: 2020.01.08 THURINGISCHES INSTITUT FUR TEXTIL & KUNST FORSCHUNG
  • EP2640776B1 patent drawingFigure 1
  • EP2640776B1 patent drawingFigure 1
  • EP2640776B1 patent drawingFigure 2A~2B

AI summary

The invention discloses stabilized and/or functionalized polyamide compositions containing at least one stabilizing and/or functionalizing metallic salt and organoligand complex compound as a polymer additive. Said compositions contain a complex compound consisting of a combination of a copper salt and a 2-oxazoline derivative. The invention also discloses a method for producing a stabilized polyamide composition in which at least one polyamide and a metallic salt and organoligand complex compound are blended. The invention further discloses nitrato-[2,2'-meta-phenylene-bis-(4,5-dihydro-oxazole)]-argentate, nitrato-bis-(2-heneicosyl-4,5-dihydro-oxazole)-argentate, chloro-[2,2'-para-phenylene-bis-(4,5-dihydro-oxazole)]-cuprate und dichloro-[2,2'-para-phenylene-bis-(4,5-dihydro-oxazole)]-cuprate.