Positive Toner Composition for Stable Charging and Cleaner Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing positively chargeable toner experiences issues with charging stability and cleaning properties due to mechanical stress causing external additives to sink-in or come-off, leading to agglomeration and slipping-through during the cleaning process.
Innovation Solution
The toner is composed of toner base particles with a specific combination of first and second resin fine particles and a cleaning auxiliary particle, where the first resin fine particles have a smaller size and cover 10-20% of the surface, the second resin fine particles cover 5-12%, and the cleaning auxiliary particles have a larger size, all formed from silicone modified acrylic resin and inorganic materials, which act as spacer particles to stabilize charging and prevent slipping-through.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If silica particles are used as spacer particles to reduce sinking-in and coming-off of external additives, then the stability of external additives is improved, but charging-induced faults (fogging) occur because silica particles themselves need to be positively charged
Solution Approach 1:
The patent introduces resin fine particles as intermediary spacer particles that do not require positive charging. These resin particles mediate between the toner base and the cleaning blade, preventing direct contact and mechanical stress on external additives without generating charging-induced faults, thus resolving the contradiction between stability improvement and harmful factor generation
Solution Approach 2:
The patent changes the material parameter of spacer particles from silica (inorganic) to resin (organic), and adjusts the particle size distribution (30-50 nm first particles, 80-120 nm second particles) to optimize both stability and charging properties, eliminating fogging while maintaining additive stability
2Reliability
If only large particle size resin fine particles are used as spacer particles to avoid charging-induced faults, then charging stability is improved, but cleaning properties deteriorate due to insufficient prevention of slipping-through
Solution Approach 1:
The patent segments the spacer particle system into two distinct size classes: first resin fine particles (30-50 nm) for primary spacing and adhesion, and second resin fine particles (80-120 nm) for enhanced spacing and anti-slipping. This segmentation allows each size to perform its specific function optimally, resolving the contradiction between charging stability and cleaning properties
Solution Approach 2:
The patent applies different particle sizes at different functional locations: smaller first particles (30-50 nm) provide local adhesion and spacing close to the toner base surface, while larger second particles (80-120 nm) provide extended spacing and prevent slipping-through at the cleaning interface, achieving both charging stability and cleaning effectiveness
3Ease of operation
If external additives are attached to toner base particle surface to improve flowability and charging properties, then toner performance is improved, but mechanical stress causes sinking-in or coming-off leading to agglomeration
Solution Approach 1:
The patent applies resin fine particles as a protective cushioning layer before mechanical stress occurs during cleaning. This pre-applied spacer layer absorbs and distributes mechanical stress, preventing direct contact between the cleaning blade and external additives, thus preventing sinking-in and coming-off while maintaining flowability and charging properties
Data Source
Figure 1
Figure 2~3
AI summary
Positively chargeable toner (101) has toner particles including a toner base particle (102) and an external additive (103) attached to its surface. The external additive (103) includes first and second resin fine particles (104, 105) of silicone modified acrylic resin and a cleaning auxiliary particle (106). The first resin fine particle (104) has a number average primary particle size of 30 nm or more but 50 nm or less, and the ratio of its coverage of the surface region of the toner base particle (102) is 10% or more but 20% or less. The second resin fine particle (105) has a number average primary particle size of 80 nm or more but 120 nm or less, and the ratio of its coverage of the surface region of the toner base particle (102) is 10% or more but 20% or less. The cleaning auxiliary particle (106) has a number average primary particle size of 100 nm or more but 300 nm or less.