Toner Surface Layer Organic Silicon Polymer Coating
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Solution Overview
Problem
Current toners for electrostatic latent image development face challenges in maintaining high-quality image reproduction across varying environments, particularly in terms of durability, low-temperature fixability, and resistance to changes in temperature and humidity, which affects image density and causes soiling of apparatus parts.
Innovation Solution
A toner with a surface layer containing an organic silicon polymer, specifically formulated to enhance environmental stability, low-temperature fixability, and development durability, achieved through a sol-gel method that provides a uniform and stable organic silicon polymer coating on toner particles, improving hydrophobicity and charge stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inorganic fine particles are strongly fixed to toner particle surfaces, then high-temperature storage stability is improved, but bleeding of release agent and resin component occurs through gaps between particles
Solution Approach 1:
The patent applies composite materials by combining inorganic fine particles with an organic silicon polymer coating layer. The inorganic particles provide structural stability and heat resistance, while the organic silicon polymer matrix fills gaps between particles and provides a continuous barrier that prevents bleeding of release agent and resin components, thus resolving the contradiction between storage stability and bleeding prevention.
Solution Approach 2:
The organic silicon polymer forms a thin film coating on the toner particle surface that encapsulates the inorganic fine particles. This flexible yet protective film prevents the release of harmful substances through particle gaps while maintaining the structural integrity provided by the inorganic particles, addressing both the stability and bleeding issues.
2Manufacturing precision
If a silane coupling agent is added to the reaction system to prevent colorants and polar substances from becoming exposed, then charge amount distribution is improved, but hydrolytic polycondensation and precipitate amount are insufficient
Solution Approach 1:
The patent changes the chemical parameters of the silane coupling agent by specifying particular structural formulas (with particular R1, R2, R3 groups) and controlling the polymerization conditions. This ensures sufficient hydrolytic polycondensation occurs to form adequate precipitates on the toner surface, while maintaining uniform charge distribution. The parameter optimization resolves the contradiction between charge uniformity and environmental stability.
3Duration of action of stationary object
If the toner is stored in a wide variety of environments for a long time, then development durability should be maintained, but charge amount and surface properties change due to temperature and humidity
Solution Approach 1:
The organic silicon polymer acts as an intermediary layer between the toner core and the external environment. It mediates the interaction between temperature and humidity and the toner's internal components, preventing direct environmental effects that would cause charge amount changes and surface property deterioration. This intermediary protection maintains development durability over long storage periods.
Solution Approach 2:
The organic silicon polymer coating serves as a sacrificial protective layer that absorbs environmental stress first, protecting the core toner components. This outer layer can degrade or change slightly while maintaining the structural and functional integrity of the underlying toner particles, thus preserving development durability.
4Productivity
If a binder resin suitable for low temperature fixing is selected, then high-speed image formation is achieved, but developing performance and durability are affected
Solution Approach 1:
The patent applies local quality by having different regions of the toner particle with different properties. The core contains the binder resin optimized for low-temperature fixing (enabling high-speed formation), while the surface layer contains organic silicon polymer and inorganic particles that provide stability and protection for developing performance. Each region performs its specialized function, resolving the contradiction between speed and durability.
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 exhibits improved environmental stability, low-temperature fixability, and development durability, reducing soiling and maintaining image quality over a wide range of conditions, while suppressing bleeding and resin component ooze, thus enhancing storage stability and image density consistency.
Implementation Method 1
improving hydrophobicity and charge stability
Implementation Method 2
achieved through a sol-gel method that provides a uniform and stable organic silicon polymer coating on toner particles
Implementation Method 3
One of the causes of changes in charge amount and storage stability of the toner due to temperature and humidity is a phenomenon called bleeding in which a release agent and a resin component in the toner ooze out from the interior of the toner particle to the surface of the toner particle
Data Source
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AI summary
A toner (4) having good development durability, storage stability, environmental stability, and low-temperature fixability is provided. The toner contains toner particles each including a surface layer that contains an organic silicon polymer. The organic silicon polymer contains a unit having a specific structure. The average thickness Dav. of the surface layers is a specific value and the silicon concentration determined by ESCA is 2.5% or more. The toner has a shape factor SF-2 of 140 or more and 260 or less and an average circularity of 0.970 or more and 0.990 or less.