Toner Composite Particles Embedding Inorganic Fillers
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Solution Overview
Problem
Existing toners used in electrophotographic systems face challenges with high-speed printing in the print-on-demand field, requiring improved low-temperature fixability and charging stability, while also experiencing end portion soiling due to detachment of fine particles from the medium.
Innovation Solution
A toner composition that includes toner particles with a binder resin and a release agent, along with composite particles on the surface of the toner particles. The composite particles consist of fine particles A with an organosilicon compound and fine particles B of inorganic materials, where the fine particles B are partially embedded in fine particles A, achieving specific proportions and embedding ratios to enhance adhesion and resistance to detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If fine particles (silica added to vinyl monomer) are externally added to toner base particles to improve flowability, then the flowability of the toner is improved, but the fine particles may be detached from the medium due to stress from conveying roller, causing end portion soiling
Solution Approach 1:
The patent uses composite particles consisting of fine particles A (organosilicon compound with siloxane bond) and fine particles B (inorganic fine particles) combined with a binder resin. This composite structure provides both the flowability benefits of fine particles and the adhesion strength needed to prevent detachment during conveying, thereby eliminating end portion soiling while maintaining improved flowability.
Solution Approach 2:
The patent controls specific parameters including the embedding ratio of fine particles B into fine particles A (30-90%), the proportion of silicon atoms in different structures (Pa, Pb, Pc relationships), and the penetration value of the release agent (4 or less at 25°C). These parameter controls ensure that the fine particles remain firmly attached to the medium under conveying stress while maintaining the desired flowability characteristics.
2Object-generated harmful factors
If the release agent has low penetration to prevent fine particle detachment, then end portion soiling is prevented, but low-temperature fixability and charging stability requirements for high-speed printing may not be met
Solution Approach 1:
The patent precisely controls the penetration value of the release agent to be 4 or less at 25°C, which prevents fine particle detachment and end portion soiling. Simultaneously, the patent optimizes other parameters including the embedding ratio of fine particles (30-90%), the organosilicon compound structure (Pa, Pb, Pc proportions), and the binder resin characteristics to ensure that low-temperature fixability and charging stability requirements for high-speed printing are still met.
Solution Approach 2:
The composite particles with organosilicon compound and inorganic fine particles embedded at specific ratios provide both adhesion strength to prevent soiling and the necessary thermal and electrical properties for low-temperature fixability and charging stability. The composite structure allows the release agent to maintain low penetration while the composite particles themselves provide the necessary functional 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 achieves high low-temperature fixability and charging stability, while preventing end portion soiling by ensuring strong adhesion of the composite particles to the toner particles and the release agent, which covers the fixed image and buries the composite particles, increasing the contact area and resistance to external forces.
Implementation Method 1
The release agent has a penetration of 4 or less at 25° C.
Implementation Method 2
Each of the fine particles B is partially embedded at the surface of each of the fine particles A
Data Source
AI summary
A toner includes toner particles each containing a binder resin and a release agent, and composite particles each present on a surface of each toner particle. The release agent has a penetration of 4 or less at 25° C. The composite particles include fine particles A each containing an organosilicon compound having a siloxane bond, the organosilicon compound serving as a binder component, and fine particles B formed of inorganic fine particles. Each fine particle B is partially embedded at the surface of each fine particle A. In the fine particles A, the proportions of di- to tetra-functional silicon atoms satisfy predetermined requirements. The fine particles B have a number-average diameter of primary particles of 0.01 μm or more and 0.06 μm or less. In the composite particles, the average value of embedding ratios of the fine particles B to the fine particles A is 30% or more and 90% or less.