Ionic Polymer Flocculants for Toner Particle Size Control
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Solution Overview
Problem
Current toner production methods face challenges in achieving consistent particle size and growth through flocculation, often requiring large pH changes or unstable conditions, which can lead to inefficient particle formation and size control.
Innovation Solution
The process involves forming an aqueous dispersion of polymer binder and colorant stabilized by ionic surfactants and flocculants, where the pH is adjusted to configure the flocculants into specific conformations (random coil or extended chain) to promote flocculation, followed by heating above the glass transition temperature to achieve desired particle sizes ranging from 3-15 microns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If large pH changes are applied to promote flocculation, then particle growth is achieved, but manufacturing precision and stability deteriorate
Solution Approach 1:
The patent employs controlled pH adjustment as a parameter change to trigger conformational transition of the ionic polymer flocculant from coiled to extended state, enabling flocculation with minimal pH change. This resolves the contradiction by achieving particle growth (26) through precise parameter control rather than large pH shifts, thereby maintaining manufacturing precision (29).
Solution Approach 2:
The patent utilizes the phase transition (conformational change) of the ionic polymer flocculant from random coil to extended chain configuration in response to pH change. This phase transition mechanism enables controlled flocculation and particle growth while maintaining stability, resolving the contradiction between achieving particle growth and maintaining manufacturing precision.
2Quantity of substance
If ionic polymer flocculant is used to promote flocculation, then particle growth is achieved, but stability of dispersion deteriorates
Solution Approach 1:
The patent employs a dynamic system where the ionic polymer flocculant can reversibly change conformation based on pH conditions. The flocculant transitions from coiled (stable dispersion) to extended (flocculation) state as needed, allowing the system to adapt between stability and particle growth requirements, thus resolving the contradiction between particle growth (26) and dispersion stability (13).
Solution Approach 2:
By controlling pH as a parameter, the patent enables reversible conformational changes in the ionic polymer flocculant. This parameter control allows the system to switch between stable dispersion (coiled state) and active flocculation (extended state), resolving the contradiction between maintaining stability and achieving particle growth.
3Productivity
If pH is adjusted to configure flocculant into extended chain configuration, then flocculation efficiency is improved, but use of energy increases
Solution Approach 1:
The patent uses minimal pH adjustment to trigger the conformational change of the ionic polymer flocculant from coiled to extended state. This efficient parameter change approach achieves effective flocculation with minimal energy input for pH control, resolving the contradiction between flocculation efficiency (39) and energy consumption (19).
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
This method allows for precise control of toner particle size and growth, reducing the need for extensive pH changes and stabilizing the dispersion, resulting in consistent and efficient production of toner particles with controlled size distribution.
Implementation Method 1
The pH of the dispersion may be adjusted to configure the ionic polymer flocculent into a random coil configuration. The pH of the dispersion may then be adjusted to configure the ionic polymer flocculent into a relatively extended chain configuration wherein the ionic groups become available to promote flocculation
Implementation Method 2
the ionic groups become available to promote flocculation of the aggregates to a desired size
Implementation Method 3
ionic polymer flocculant containing a plurality of ionic functional groups of opposite charge to the ionic surfactant
Implementation Method 4
Heating may then be applied to a temperature above a glass transition temperature of the polymer binder along with collection of particulate
Data Source
AI summary
The present disclosure relates to a process for producing a toner particulate composition from aqueous dispersions containing aggregates of a polymer binder and other toner ingredients. An ionic surfactant may be used to form the dispersion along with an ionic polymer flocculent wherein the ionic polymer flocculent undergoes a molecular conformational change, which may be triggered by pH adjustment, leading to flocculation and particle growth.