Core-Shell Toner Resin for Fixability and Storage
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Solution Overview
Problem
Existing toners for developing electrostatic charge images face challenges in achieving a balance between low temperature fixability, heat-resistant storage properties, charging uniformity, and transferability under high temperature and high humidity conditions, with prior solutions either compromising on one or more of these properties.
Innovation Solution
A toner with a core-shell structure, where the binder resin contains a hybrid crystalline polyester resin in the core portion and a hybrid amorphous polyester resin in the shell portion, enhancing the affinity and dispersion of components to improve charging uniformity and transferability while maintaining low temperature fixability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a crystalline polyester resin is used in the binder resin to achieve low temperature fixability, then the low temperature fixability is improved, but the heat-resistant storage property deteriorates
Solution Approach 1:
The binder resin is divided into two distinct portions: a core portion containing crystalline polyester resin for low temperature fixability, and a shell portion containing amorphous polyester resin for heat-resistant storage property. This segmentation allows each portion to independently contribute its specific functional properties without compromising the other.
Solution Approach 2:
Different regions of the binder resin are assigned different material compositions tailored to local functional requirements. The core portion uses crystalline polyester resin with specific melting properties for low temperature fixation, while the shell portion uses amorphous polyester resin with high glass transition temperature for heat resistance, creating localized functional zones within the single binder resin particle.
2Temperature
If a crystalline polyester resin and amorphous resin are mixed to achieve low temperature fixability, then the low temperature fixability is improved, but the charging uniformity deteriorates
Solution Approach 1:
The binder resin is segmented into core and shell portions with distinct material compositions. The core contains crystalline polyester resin and the shell contains amorphous polyester resin, preventing the incompatibility issues that arise from direct mixing while maintaining the low temperature fixability benefits of crystalline resin.
3Temperature
If a crystalline polyester resin is used to achieve low temperature fixability, then the low temperature fixability is improved, but the transferability under high temperature and high humidity condition deteriorates
Solution Approach 1:
The binder resin is segmented into core and shell portions. The core portion with crystalline polyester resin provides low temperature fixability, while the shell portion with amorphous polyester resin provides stability under high temperature and high humidity conditions, ensuring reliable transferability.
Solution Approach 2:
The binder resin is constructed as a composite material system combining crystalline polyester resin and amorphous polyester resin in a core-shell configuration. This composite structure integrates the advantageous properties of both resin types: the sharp melting behavior of crystalline resin for low temperature fixation and the thermal stability of amorphous resin for reliable performance under high temperature and 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 toner achieves excellent low temperature fixability along with improved heat-resistant storage properties and charging uniformity, and enhanced transferability under high temperature and high humidity conditions, addressing the trade-offs present in previous solutions.
Implementation Method 1
the crystalline portion is melted when the temperature exceeds the melting point of the crystalline polyester by the temperature history at the time of fixing
Implementation Method 2
a hybrid crystalline polyester resin formed by chemical bonds of a crystalline polyester resin unit with an amorphous resin unit other than a polyester resin in a core portion and a hybrid amorphous polyester resin formed by chemical bonds of an amorphous polyester resin unit with an amorphous resin unit other than a polyester resin in a shell portion
Data Source
AI summary
Provided is a means to exhibit excellent low temperature fixability and to improve all of the heat-resistant storage property of a toner, charging uniformity, and transferability under a high temperature and high humidity condition.A toner for developing electrostatic charge image which contains at least a binder resin, in which the binder resin has a core-shell structure having a core portion which contains a hybrid crystalline polyester resin formed by chemical bonds of a crystalline polyester resin unit with an amorphous resin unit other than a polyester resin and an amorphous resin and a shell portion which contains a hybrid amorphous polyester resin formed by chemical bonds of an amorphous polyester resin unit with an amorphous resin unit other than a polyester resin.