Core-Shell Toner with Functionalized Shell for Uniform Charge
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Solution Overview
Problem
Existing toner production methods face challenges with long-term stability and reliability, particularly with small triboelectrically charged particles, due to nonuniform charge distribution and unpredictability, which affects print quality and control in electrostatographic apparatuses.
Innovation Solution
A core-shell toner composition is developed, featuring a first latex core and a second latex shell functionalized with acetoacetoxy groups, which enhances triboelectric robustness and uniform charge retention, achieved through a process involving emulsion polymerization and aggregation, allowing for improved adhesion and humidity resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If small toner particles (about 5 micron diameter) are used to enable offset print quality, then print quality is improved, but long-term stability and reliability deteriorate due to nonuniform charge distribution and unpredictable triboelectric charging
Solution Approach 1:
The patent changes the chemical composition parameters of the toner particle by incorporating specific functional groups (carboxyl, hydroxyl, amine, or epoxy groups) with controlled amounts (0.1-10 mmol per gram of toner). This chemical modification alters the surface properties and charge distribution characteristics, enabling small particles to achieve uniform charging and improved reliability without sacrificing print quality
Solution Approach 2:
The patent creates a composite toner material by combining pigment particles with a polymer binder that contains specific functional groups. This composite structure allows the toner to exhibit both the small particle size needed for offset print quality and the enhanced charge uniformity provided by the functional groups, resolving the contradiction between print quality and reliability
2Reliability
If triboelectric charging is used to charge toner particles, then charging is achieved, but nonuniform charge distribution occurs resulting in high electrostatic adhesion and difficult control
Solution Approach 1:
The patent modifies the surface chemical parameters of the toner by introducing functional groups (carboxyl, hydroxyl, amine, or epoxy) that alter the triboelectric properties. These functional groups promote more uniform charge distribution during triboelectric charging, reducing the charge patch effect and improving controllability while maintaining charging capability
Solution Approach 2:
The functional groups act as intermediaries on the toner surface that mediate the triboelectric charging process. They provide specific interaction sites that facilitate more uniform charge distribution, acting as a bridge between the friction contact and the bulk material, thereby improving charge uniformity without eliminating triboelectric charging
3Ease of manufacture
If conventional toner production methods are used, then production is achieved, but production time is long and control of charging is poor
Solution Approach 1:
The patent incorporates functional groups into the polymer binder during the toner formulation stage, before the actual toner production process. This preliminary incorporation of functional groups ensures that the charging control properties are built into the material itself, eliminating the need for additional post-processing steps and reducing overall production time while maintaining ease of manufacture
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 core-shell toner composition provides stable and uniform triboelectric charging, reducing production time and manufacturing costs, while enhancing print quality and reliability by minimizing defects and variability in toner performance.
Implementation Method 1
Triboelectric charging may occur either by mixing the toner with larger carrier beads in a two component development system or by rubbing the toner between a blade and donor roll in a single component system
Implementation Method 2
tons may be formed by aggregating a colorant with a latex polymer formed by emulsion polymerization
Implementation Method 3
heating the core-shell toner at a temperature above the glass transition temperature of the second latex
Data Source
AI summary
A toner having its surface functionalized with functional groups, and processes for producing the same, are provided.