Electrographic Toner Silica Additives for Stable Charging and Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrographic toners face challenges in achieving optimal charge stability, thermal stability, and cleaning performance due to the use of titanium dioxide, which is hazardous and can cause excessive triboelectric charging, leading to issues like OPC film formation and poor image quality.
Innovation Solution
Incorporating a multi-particulate additive comprising aluminum oxide, small and large sol-gel silica particles, and fumed silica treated with polydimethylsiloxane (PDMS) on the toner surface to improve charge control, prevent charge-up phenomena, and enhance specific surface area, thereby improving thermal stability and cleaning properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If titanium dioxide is used in electrographic toner, then charge stability is improved, but harmful effects occur including excessive triboelectric charging, OPC film formation, and poor image quality
Solution Approach 1:
The patent removes titanium dioxide from the toner composition and replaces it with alternative materials (aluminum oxide, silica, fumed silica) that do not cause excessive triboelectric charging. This extraction of the harmful substance eliminates the harmful effects while maintaining charge stability through the alternative materials.
Solution Approach 2:
The patent converts the harmful triboelectric charging effect into a beneficial controlled charging mechanism by using alternative materials that provide sufficient charge stability without excessive charging. The multi-particulate additive system controls the triboelectric effects to achieve optimal performance.
2Reliability
If titanium dioxide is used in electrographic toner, then charge stability is improved, but harmful effects occur including OPC film formation and poor image quality
Solution Approach 1:
The patent removes titanium dioxide from the toner composition which is the cause of OPC film formation. The alternative materials (aluminum oxide, silica, fumed silica) do not cause this harmful effect, thereby eliminating OPC film formation while maintaining charge stability.
3Reliability
If multi-particulate additive is incorporated on toner surface, then charge control and cleaning performance are improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines multiple functions (charge control, cleaning performance, thermal stability) into a single multi-particulate additive system applied to the toner surface. This merging approach achieves multiple improvements without proportionally increasing manufacturing complexity, as the additives are incorporated in a unified process.
Solution Approach 2:
The patent uses a composite additive system comprising aluminum oxide, silica, and fumed silica particles with specific size distributions and surface treatments. This composite material approach provides enhanced charge control and cleaning performance while the materials are readily available and can be incorporated using standard mixing techniques.
4Stability of the object's composition
If multi-particulate additive is incorporated on toner surface, then thermal stability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines thermal stability enhancement with charge control and cleaning performance in the same multi-particulate additive system. The aluminum oxide, silica, and fumed silica particles provide thermal stability while the surface treatment with polydimethylsiloxane enhances cleaning properties, all in one additive package.
Solution Approach 2:
The patent optimizes the particle size distribution parameters of the additive components (aluminum oxide 10-30 nm, silica 20-130 nm, fumed silica 30-50 nm) and their concentrations in the toner formulation. These parameter optimizations achieve enhanced thermal stability and cleaning performance while maintaining manufacturability through standard processing techniques.
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 multi-particulate additive enhances triboelectric charge performance, improves image durability, and reduces adhesive force during printing, resulting in better image quality and stability, while avoiding the use of hazardous materials like titanium dioxide.
Implementation Method 1
the multi-particulate additive can enhance triboelectric charge performance
Implementation Method 2
small sol-gel silica particles having a particle size distribution from 20 nm to 50 nm, and large sol-gel silica particles having a particle size distribution from 90 nm to 130 nm
Implementation Method 3
fumed silica particles surface-treated with polydimethylsiloxane (PDMS)
Implementation Method 4
fumed silica particles surface-treated with polydimethylsiloxane (PDMS)... reduces adhesive force during printing
Data Source
AI summary
An electrographic toner can include toner particles having a multi-particulate additive disposed on an exterior surface of the toner particles. The toner particles can have a specific surface area from 3.0 m2/g to 3.65 m2/g and can include a binder resin, a colorant, and a releasing compound. The multi-particulate additive can include aluminum oxide particles, small sol-gel silica particles having a particle size distribution from 20 nm to 50 nm, large sol-gel silica particles having a particle size distribution from 90 nm to 130 nm, and fumed silica particles surface-treated with polydimethylsiloxane (PDMS).