Toner Composition With Controlled Additive Adhesion for Reuse Stability
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Solution Overview
Problem
Reused toner in electrophotographic image forming apparatuses often suffers from performance changes, leading to image defects such as image fog and white streaks due to depletion of components or contamination with external additives.
Innovation Solution
A toner composition comprising toner base particles with a binder resin, ester wax, and colorant, and an external additive of titanium oxide and silica, with specific adhesive strengths between the additive and particles, ensuring stable adhesion and reduced image defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If toner is reused after collection from the photoconductor, then productivity is improved by reducing waste, but image quality deteriorates due to component depletion and contamination
Solution Approach 1:
The invention extracts and removes contaminants and depleted components from reused toner through filtration and cleaning mechanisms, separating harmful substances from the toner particles to maintain image quality while enabling reuse
Solution Approach 2:
The invention changes physical parameters of the toner system by adjusting adhesive strength parameters and chargeability parameters through controlled processing, transforming the toner properties to maintain performance after reuse
2Reliability
If external additives are strongly adhered to toner base particles, then chargeability is improved, but fluidity deteriorates due to excessive adhesion
Solution Approach 1:
The invention applies local quality by creating non-uniform adhesion characteristics where external additives are strategically positioned on specific regions of toner base particles, ensuring adequate chargeability while preserving fluidity through controlled local bonding
Solution Approach 2:
The invention optimizes the adhesive strength parameter to a specific range that balances chargeability and fluidity, changing the physical-chemical parameters of the external additive-binder interface to achieve simultaneous improvement in both properties
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 composition maintains performance consistency, reducing image defects like fog and streaks, while enhancing low temperature fixability, storage stability, and heat resistance.
Implementation Method 1
an adhesive strength between the external additive and the toner base particles that is in a range of 50 mN/m to 90 mN/m when measured by a contact angle method
Implementation Method 2
desorbed external additive is removed by centrifugation
Implementation Method 3
desorbed external additive is removed by centrifugation
Implementation Method 4
desorbed external additive is removed by centrifugation, and then remaining toner base particles are dried
Data Source
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AI summary
A toner is comprised of toner particles and external additive adhering to the surface of the toner particles. The toner particles are formed from a binder resin, an ester wax, and a colorant. The external additive comprises a titanium oxide and silica. A first adhesive strength between the external additive and the toner base particles is in a range of 90 to 100% when measured as a ratio of X-ray spectroscopic intensity of titanium for toner particles before and after a washing process, and a second adhesive strength between the external additive and the toner base particles is in a range of 50 to 80% when measured as a ratio of X-ray spectroscopic intensity of silicon measured for toner before and after another washing process.