Toner External Additive Wall Friction Angle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing toners used in electrophotographic image-forming methods face challenges in maintaining stable charging performance and effective cleaning performance, leading to image defects due to increased electrostatic attachment forces and reduced cleaning efficiency, especially at higher speeds and longer apparatus life.
Innovation Solution
A toner with an external additive having a charge control agent on its surface, characterized by a wall friction angle of not more than 25.0°, a number-average particle diameter of primary particles between 70 nm and 500 nm, and a solidity of at least 0.40 and not more than 0.90, which reduces frictional forces and enhances cleaning performance without compromising flowability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a composition containing a charge control agent and a fluidizing agent is externally added to spherical toner to improve charging capability, then charging performance is improved, but cleaning performance deteriorates due to increased electrostatic attachment force
Solution Approach 1:
The invention changes the wall friction angle parameter of the external additive to not more than 25.0°, which is a specific parameter modification that simultaneously addresses both charging and cleaning performance requirements
Solution Approach 2:
The invention uses a composite external additive structure combining inorganic fine particles (silica, alumina, or titania) with a charge control agent, creating a material that provides both charging capability and appropriate friction characteristics for effective cleaning
2Manufacturing precision
If the electrostatic attachment force between photosensitive drum and toner is increased to improve charging performance, then image quality is improved, but cleaning becomes more difficult
Solution Approach 1:
The invention modifies the wall friction angle parameter of the external additive to a specific range (not more than 25.0°), which changes the frictional characteristics to enable effective cleaning even when electrostatic attachment force is increased for better charging performance
Solution Approach 2:
The invention applies different functional properties to different aspects of the external additive: the charge control agent provides charging capability while the inorganic particle structure with controlled wall friction angle provides cleaning facilitation, allowing local optimization of both functions
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 toner achieves improved charging performance, maintains excellent cleaning performance, and suppresses image defects, ensuring stable operation at higher speeds and extended apparatus life without reducing the contact angle between the photosensitive drum and blade.
Implementation Method 1
the external additive A i) has a charge control agent present on the surface thereof
Implementation Method 2
ii) has a wall friction angle θ calculated from the following formula (1) of not more than 25.0°
Data Source
AI summary
A toner comprising an external additive A, and a toner particle containing a binder resin and a colorant, wherein the external additive A: i) is an external additive that has a charge control agent on the surface thereof; ii) has a wall friction angle θ calculated from the following formula (1) of not more than 25.0°θ=τ/5.0 formula (1);iii) has a number-average particle diameter (D1) of primary particles of at least 70 nm and not more than 500 nm; and iv) has a solidity as given by the following formula (2) of at least 0.40 and not more than 0.90solidity=area of external additive A/area of region encompassed by envelope for external additive A formula (2).