Toner External Additive Stabilizes Charge in High Humidity
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Solution Overview
Problem
Existing toners face challenges in maintaining charge stability, especially in high-temperature, high-humidity environments, leading to overcharging, scattering, and reduced dot reproducibility.
Innovation Solution
A toner formulation incorporating composite fine particles with specific organosilicon compounds and titanium oxide or titanic acid compound fine particles, which are externally added to stabilize charge distribution and reduce contamination of charge-applying members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a low-resistance titanium-based compound is externally added to reduce overcharging, then charge stability is improved, but the compound attaches to charge-applying members and degrades charging ability over time
Solution Approach 1:
The patent introduces composite fine particles as intermediary substances that mediate between the titanium-based charge control compound and the charge-applying members. These composite particles prevent direct attachment of the titanium compound to the charge-applying members while still enabling charge control, thus resolving the contradiction between charge stability and long-term charging ability.
Solution Approach 2:
The patent uses composite fine particles consisting of multiple components (including titanium-based compounds combined with other materials) to create a system that maintains charge stability without the harmful attachment effect. The composite structure allows the titanium-based compound to fulfill its charge control function while the other components prevent attachment to charge-applying members.
2Productivity
If printing speed is increased to meet high-speed printing demands, then productivity is improved, but toner easily removes from charge-applying members and scatters
Solution Approach 1:
The patent changes the physical and chemical parameters of the toner by incorporating specific external additives and modifying the toner composition. This alters the adhesion properties and charge characteristics of the toner, enabling it to maintain strong attachment to charge-applying members even at high printing speeds, thus resolving the contradiction between productivity and toner scattering.
3Object-affected harmful factors
If triboelectrification is reduced in high-temperature, high-humidity environments, then electrostatic adhesion decreases, but charge stability deteriorates
Solution Approach 1:
The patent replaces the triboelectrification mechanism (which is sensitive to environmental conditions) with an alternative charge application mechanism using the external additives and composite fine particles. This substitution provides a more environmentally stable charge application method that maintains charge stability in high-temperature, high-humidity conditions.
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 proposed toner solution effectively reduces overcharging, improves dot reproducibility, and minimizes toner scattering over extended periods, even in harsh environmental conditions.
Implementation Method 1
fine particles C including either titanium oxide fine particles or titanic acid compound fine particles and having a volume resistivity of 2.0×109 Ω·cm to 2.0×1013 Ω·cm
Implementation Method 2
fine particles A containing an organosilicon compound with siloxane bonds as a binder component
Implementation Method 3
in high-temperature, high-humidity environments, where triboelectrification is less likely to occur, the electrostatic adhesion between the charge-applying members and the toner decreases
Implementation Method 4
the electrostatic adhesion between the charge-applying members and the toner decreases
Data Source
AI summary
A toner contains toner particles and an external additive on the surfaces of the toner particles. The external additive includes composite fine particles that include fine particles A containing an organosilicon compound with siloxane bonds as a binder component and fine particles B at least partially embedded in the surfaces of the fine particles A with an embedding rate of 30% to 90% on average, and fine particles C including titanium oxide or titanic acid compound fine particles and having a volume resistivity of 2.0×109 to 2.0×1013 Ω·cm and a number average diameter of primary particles of 10 to 100 nm. The organosilicon compound contains bifunctional, trifunctional, and tetrafunctional silane monomers with specific relationships. The number average diameter X of primary particles of the composite fine particles and the number average diameter Y of primary particles of fine particles C satisfy 1.0≤X/Y≤10.0.