Toner Composition Charge Distribution via Inertial Classification
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Solution Overview
Problem
Conventional toners face challenges in achieving high image quality, transferability, and image density stability due to differences in charge quantity between particles of varying diameters, leading to issues like fogging and deteriorated image density.
Innovation Solution
A toner composition where particles are classified into two groups with specific surface potential change rates, ensuring a balanced charge distribution across different diameters, using an inertial classifier to achieve a ratio of 1.5≤Al/As≤2.5, where Al and As represent the change rates of surface potential in each group, thereby optimizing charge retention and surface charge density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the particle diameter of the toner is reduced to improve image quality and dot reproducibility, then the image quality is improved, but the charge quantity per particle decreases leading to poor transferability
Solution Approach 1:
The patent applies local quality by creating a shell layer with different composition and charge properties than the core. The shell layer contains charge control agents and has different surface characteristics, allowing small particles to have enhanced charge retention locally at the surface while maintaining small overall size for image quality. This resolves the contradiction by making the charge distribution non-uniform across the particle structure.
2Reliability
If the charge quantity per particle is increased to improve transferability, then the transferability is improved, but the image density deteriorates due to excessive charge
Solution Approach 1:
The patent changes parameters by controlling the type and amount of charge control agents in the shell layer, adjusting the core-shell ratio, and modifying the composition to achieve optimal charge quantity. This allows tuning the charge parameters to satisfy both transferability requirements and image density stability, resolving the contradiction through parameter optimization.
3Reliability
If inorganic fine particles are added to increase charge quantity per particle, then the charge quantity is increased, but the charge quantity per unit weight becomes too large causing image density instability
Solution Approach 1:
The patent uses composite materials by combining organic binder resin with inorganic fine particles in a core-shell structure. The inorganic particles are embedded in the shell layer rather than uniformly distributed, creating a composite structure that provides charge control while maintaining image density stability. This resolves the contradiction by spatially separating the charge-providing inorganic particles from the bulk toner composition.
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 approach enhances transferability, suppresses fogging, and stabilizes image density by ensuring a higher charge retention on smaller particles and controlled charge quantity on larger particles, resulting in improved image quality and density.
Implementation Method 1
when the toner is divided into two groups i.e. a first group and a second group with an inertial classifier
Implementation Method 2
charging a surface of the pellet type molded product Pl to −600 V by a scorotron charger
Data Source
AI summary
A toner containing a toner particle, in which the toner particle contains a binder resin and a pigment, and As and Al satisfy a specific relation, in a case when the toner is divided into two groups i.e. a first group and a second group with an inertial classifier, the first group including a larger size of the toner particles, and the second group including a smaller size of the toner particles, and the number of the toner particles in the first group being substantially equal to the number of the toner particles in the second group. Each of As and Al is a change rate of a surface potential of a pellet type molded product obtained by molding each of the toner in the first group and the toner in the second group under specific conditions is observed using a surface potentiometer under a specific conditions.