Polyamide Solid Phase Post-Condensation Gas Treatment
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Solution Overview
Problem
Existing processes for producing polyamides lack sufficient processing stability, leading to issues such as thermal degradation and increased viscosity during melt extrusion, which results in reduced throughput and increased contamination in film production.
Innovation Solution
A process involving solid phase post-condensation of polyamides with a gas mixture containing inert gases, water, acid, anhydride, lactone, ammonia, or amine at controlled temperatures and pressures, which reduces residual moisture and end-group imbalances, enhancing processing stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If polyamide is processed during melt extrusion, then production throughput is increased, but thermal degradation and viscosity increase occur leading to processing instability
Solution Approach 1:
The patent applies preliminary action by conducting solid phase post-condensation treatment before melt extrusion processing. This pre-treatment adjusts the end group ratio and reduces residual moisture in the polyamide granules, thereby preventing thermal degradation and viscosity increase during subsequent melt extrusion, ensuring processing stability while maintaining high throughput
2Loss of substance
If polyamide undergoes solid phase post-condensation with inert gas only, then residual moisture is reduced, but end group imbalance persists causing processing issues
Solution Approach 1:
The patent applies parameter changes by modifying the gas composition parameters during solid phase post-condensation. Instead of using only inert gas, the patent introduces reactive gases (oxygen at 0.1-10% or carbon dioxide at 1-50%) to change the chemical reaction parameters, enabling end group adjustment through controlled oxidation or carboxylation while simultaneously reducing residual moisture
3Stability of the object's composition
If reactive gases are added to solid phase post-condensation, then end group balance is improved, but process complexity increases
Solution Approach 1:
The patent applies local quality by making the gas composition adaptable to specific needs. The gas mixture can be customized based on the desired end group adjustment: oxygen-rich mixtures for amino end group reduction, or carbon dioxide-rich mixtures for carboxyl end group increase. This localized optimization simplifies the overall system by allowing selective gas composition rather than requiring complex continuous control
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 process results in polyamides with improved stability during melt extrusion, reducing thermal degradation, viscosity, and monomer recovery, leading to increased production efficiency and reduced contamination in final products like films and fibers.
Implementation Method 1
the polyamide is treated during the solid phase post-condensation with a gas, the inert gas, water and acid or anhydride or lactone or their mixtures or ammonia or Contains amine or mixtures thereof
Implementation Method 2
solid phase post-condensation of polyamides with a gas mixture containing inert gases, water, acid, anhydride, lactone, ammonia, or amine at controlled temperatures and pressures
Implementation Method 3
reduces residual moisture and end-group imbalances
Data Source
AI summary
The invention relates to a method for producing processing-stable polyamides, wherein the polyamide is treated with a gas that contains carrier gas (inert gas), water and acid or anhydride or lactone or mixtures thereof, or ammonia or amine or mixtures thereof, at a temperature of 130 to 200 °C and at a pressure of 0.01 to 10 bar during the solid phase post-condensation.