Core-Shell Toner Resin Compatibility for Low-Temperature Fixing
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Solution Overview
Problem
Existing toners with crystalline resin core-shell structures face challenges in achieving compatibility between the crystalline resin and binder, leading to issues with low-temperature fixability and developing performance, especially in high-speed and high-humidity environments.
Innovation Solution
A toner with a core-shell structure comprising an amorphous resin A and crystalline resin core, and an amorphous resin B shell, where the styrene-acrylic resin constitutes at least 50% of the amorphous resin A, and the compatibility between the amorphous resin A and crystalline resin is optimized to at least 50% and not more than 100%, while the compatibility between the amorphous resin B and crystalline resin is maintained at 0% to 40%, using a block polymer approach to control these interactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the compatibility between crystalline polyester and binder resin is increased to improve low-temperature fixability, then the toner surface viscosity declines and developing performance deteriorates
Solution Approach 1:
The invention divides the toner into core and shell segments with different resin compositions. The core contains crystalline polyester with amorphous binder resin for low-temperature fixing, while the shell contains amorphous resin with higher glass transition temperature for maintaining developing performance. This segmentation allows each part to optimize its function without compromising the other.
Solution Approach 2:
Different regions of the toner are assigned different resin compositions tailored to their specific functions. The core region uses crystalline polyester with high compatibility (50-100%) for low-temperature fixing, while the shell region uses amorphous resin with lower compatibility (0-40%) for maintaining surface viscosity and developing performance.
2Temperature
If the compatibility between shell material and crystalline polyester is increased to exploit the effects of crystalline polyester, then the strength of the toner declines
Solution Approach 1:
The invention separates the toner into core and shell segments where the shell contains amorphous resin with controlled low compatibility (0-40%) with crystalline polyester. This segmentation prevents the shell material from compromising toner strength while the core material provides low-temperature fixing capability.
3Stability of the object's composition
If the hydrophilicity of the shell material is increased to improve compatibility, then the developing performance in high-humidity environments declines
Solution Approach 1:
The shell material is designed with specific amorphous resin composition that maintains appropriate hydrophobicity for high-humidity developing performance while providing controlled compatibility (0-40%) with crystalline polyester. The local composition is optimized for its specific function in the shell region.
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
This configuration enhances low-energy fixing, maintains developing performance in high-speed systems, and ensures stability in high-humidity environments by uniformly melting the toner and preventing cold offset, thus fully exploiting the effects of the crystalline resin.
Implementation Method 1
the crystalline resin and toner binder do not melt uniformly during fixing
Implementation Method 2
crystalline resin... can bring about toner softening due to a viscosity drop upon melting
Implementation Method 3
there is demand to bring about toner softening at lower temperatures
Implementation Method 4
the toner surface will undergo a decline in viscosity due to the compatibility of the crystalline polyester
Data Source
AI summary
The toner comprising a toner particle having a core-shell structure that contains a core containing an amorphous resin A and a crystalline resin and a shell containing an amorphous resin B, wherein the amorphous resin A contains a styrene-acrylic resin, the content of the styrene-acrylic resin is at least 50% by mass based on the total mass of the amorphous resin A, a degree of compatibility A between the amorphous resin A and the crystalline resin is at least 50% and not more than 100%, and a degree of compatibility B between the amorphous resin B and the crystalline resin is at least 0% and not more than 40%.