Method for accelerated decolorizing a colored synthetic or non-synthetic polar-polymer material
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Solution Overview
Problem
Current methods for decolorizing colored plastics alter the chemical structure and physical properties of the polymer, and often leave residual colorants, making recycling difficult and impairing the material's properties with each recycling cycle.
Innovation Solution
A method using a decoloring composition comprising aromatic carbonic acid esters, reducing or oxidizing agents, and alkaline agents, which exposes colored synthetic or non-synthetic polar-polymer materials to these components at specific temperatures, allowing organic aromatic coloring agents to migrate out without forming covalent bonds, thus maintaining the polymer's structure and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If solubilization of polymer is used to remove color, then colorants can be separated, but the polymer structure is altered and physical properties are lost
Solution Approach 1:
The patent extracts only the colorant molecules from the polymer matrix through selective solubilization, while the polymer itself remains intact. The decolorizing composition selectively dissolves colorants with molecular weights between 230-750 g/mol, allowing their removal through filtration while preserving the polymer's chemical structure and physical properties.
Solution Approach 2:
The decolorizing composition is designed to act locally on the colorant molecules rather than the entire polymer structure. By targeting specific molecular weight ranges and using selective solvents, the treatment affects only the colorant phase while leaving the polymer phase unchanged, maintaining local structural integrity.
2Object-generated harmful factors
If chemical alteration of colorant is used to decolorize, then color is destroyed, but the polymer structure and physical features change
Solution Approach 1:
The patent introduces a decolorizing composition as an intermediary medium that facilitates colorant removal without directly reacting with the polymer. The composition contains selective solvents and catalysts that interact only with colorant molecules, transferring them from the polymer matrix to the liquid phase while the polymer remains unaffected by the chemical treatment.
Solution Approach 2:
The treatment parameters (temperature, composition concentration, exposure time) are carefully controlled to enable selective interaction with colorants. By adjusting these parameters, the process achieves effective decolorization while maintaining the polymer's physical features below critical transformation thresholds.
3Ease of manufacture
If recycling of colored plastic is performed without decolorization, then recycling process is simple, but the recycled material becomes dark grey or black and requires compounding with virgin material
Solution Approach 1:
The patent applies decolorization as a preliminary treatment step before the recycled plastic enters the standard recycling process. By removing colorants in advance, the recycled material maintains its natural color and properties, eliminating the need for subsequent compounding with virgin material or addition of titanium dioxide, thus preserving adaptability for various applications.
4Manufacturing precision
If titanium dioxide is added to recolorized recycled material, then color differences are masked, but physical properties and processability are impaired
Solution Approach 1:
The patent converts the potential harm of color variation into a benefit by achieving complete colorant removal. Instead of masking color differences with titanium dioxide (which harms processability), the process produces consistently light-colored recycled material that naturally meets color requirements, turning the decolorization challenge into a quality advantage that preserves both color consistency and processability.
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
Effectively decolorizes plastics without altering their chemical structure or physical properties, enabling efficient recycling and reuse by removing colorants without leaving residues, thereby maintaining the material's integrity and usability.
Implementation Method 1
Some methods solubilize the polymer and use additives to improve liquid solid separations after solubilization of the polymer
Implementation Method 2
the organic aromatic coloring agent migrates out of the colored synthetic and/or non-synthetic polar-polymer material
Implementation Method 3
Other methods rely on oxidizing or reducing agents to chemically alter the colorant or chromophore in the plastic. For example US 2006/0148914 A1 describes a method for substantially decolorizing a colored thermoplastic, wherein the color is destroyed by an oxidizing the color or reducing the color
Implementation Method 4
the color is destroyed by an oxidizing the color or reducing the color
Data Source
AI summary
The present invention relates to a method for accelerated decolorizing a colored synthetic or non-synthetic polar-polymer material comprising the steps of exposing the colored synthetic and/or non-synthetic polar-polymer material to a decoloring composition, wherein the decoloring composition comprises at least one aromatic carbonic acid ester, at least one reducing agent or at least one oxidizing agent, and at least one alkaline agent