Toner Particle Oxidation for Low Residual Aryl Amines
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Solution Overview
Problem
Existing methods for reducing residual aryl amines and N-arylacetoacetamides in toner particles are inadequate, often requiring long oxidation times and significant stoichiometric excesses of oxidants, and can destabilize pigment dispersions, failing to address aryl amine release during toner manufacturing.
Innovation Solution
Oxidation of toner particles containing N-arylacetoacetarylide pigments with oxidants in an aqueous phase at controlled temperature and pH, converting aryl amines to less harmful compounds like aryl nitro compounds or polyaniline, thereby reducing residual aryl amine and N-arylacetoacetamide concentrations without destabilizing the pigment dispersion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If oxidation processes are used to remove aryl amines and N-arylacetoacetamides from pigments, then the concentration of residual aryl amines decreases, but the oxidation time increases and significant stoichiometric excesses of oxidants are required
Solution Approach 1:
The patent applies parameter changes by optimizing oxidation conditions including pH (acidic to neutral range), temperature (ambient to elevated), and oxidant concentration to achieve effective removal of aryl amines within reduced timeframes. The method specifically controls these parameters to balance removal efficiency with process time.
Solution Approach 2:
The patent employs strong oxidants such as hydrogen peroxide, ozone, and potassium permanganate to accelerate the oxidation process. These potent oxidants enable faster conversion of aryl amines and N-arylacetoacetamides into less harmful compounds, reducing the time required compared to conventional oxidation methods.
2Quantity of substance
If oxidation processes are used to remove aryl amines and N-arylacetoacetamides from pigments, then the concentration of residual aryl amines decreases, but significant stoichiometric excesses of oxidants are required
Solution Approach 1:
The patent optimizes oxidant concentration and stoichiometry by adjusting pH and temperature parameters. The method uses controlled excesses of oxidant (typically 1.1 to 2.0 times the stoichiometric amount) rather than large excesses, improving efficiency while ensuring complete oxidation of residual aryl amines and N-arylacetoacetamides.
3Quantity of substance
If oxidation processes are used to remove aryl amines from pigments, then residual aryl amine content decreases, but pigment dispersion stability is compromised
Solution Approach 1:
The patent carefully controls pH (maintaining acidic to neutral conditions), temperature, and oxidant addition rates to perform oxidation in-situ within the pigment dispersion without causing destabilization. These controlled parameter changes allow removal of aryl amines while preserving pigment dispersion stability.
Solution Approach 2:
The patent uses controlled oxidation conditions where the oxidant acts as an intermediary that selectively transforms harmful aryl amine compounds into benign products without directly affecting the stability of the pigment dispersion system. The controlled environment prevents unwanted side reactions that would destabilize the dispersion.
4Quantity of substance
If conventional oxidation methods are applied to toner particles, then aryl amine removal is attempted, but the manufacturing process is not adequately addressed
Solution Approach 1:
The patent incorporates oxidation treatment as a preliminary or integrated step within the toner manufacturing process. By performing oxidation during or before the formulation and drying stages, the method removes aryl amines early when they are still accessible, avoiding the need for complex post-processing and simplifying manufacturing.
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 decreases aryl amine and N-arylacetoacetamide concentrations in toner particles by up to 90%, maintaining the quality of toner particles and manufacturing processes, and avoiding potential health and environmental risks.
Implementation Method 1
contacting the toner particles with an oxidant in an aqueous phase at a temperature and for a time sufficient to decrease a concentration of at least the residual second aryl amine in the toner particles
Data Source
AI summary
Toner particles comprising N-arylacetoacetarylide pigment compositions may contain residual aryl amines in some case. The N-arylacetoacetarylide pigment compositions comprise a diazonium coupling product of a first aryl amine and an N-arylacetoacetamide formed from a second aryl amine. Toner particles containing N-arylacetoacetarylide pigment compositions may be contacted with an oxidant in an aqueous phase to decrease the amount(s) of second aryl amine and/or N-arylacetoacetamide that remain present within the toner particles.