Urethane Modified Crystalline Resin Toner for Low-Temperature Fixing
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Solution Overview
Problem
Toner for electrostatic charge image development faces challenges in achieving both low temperature fixability and sufficient document offset resistance while minimizing excessive glossiness of the fixed image, particularly due to the use of crystalline polyester resins with low melt viscosity.
Innovation Solution
A toner composition incorporating an amorphous resin and an urethane modified crystalline resin with a crystalline polymer segment and an urethane polymer segment, where the urethane modified crystalline resin is non-compatible with the amorphous resin and contains a specific amount of ionic dissociating groups, ensuring optimal melting properties and viscoelasticity to address the issues of fixability and glossiness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a crystalline polyester resin having low melt viscosity is used as a binder resin, then low temperature fixability is improved, but heat resistant storability deteriorates
Solution Approach 1:
The invention uses a composite binder resin system comprising both amorphous resin and urethane modified crystalline resin. The amorphous resin provides low temperature fixability through its low glass transition point, while the urethane modified crystalline resin provides heat resistant storability through its high melting point and crystalline structure. This composite approach allows both contradictory requirements to be satisfied simultaneously.
Solution Approach 2:
The invention changes the chemical structure parameters of the crystalline resin by introducing urethane groups through modification. This creates a urethane modified crystalline resin that maintains crystalline properties for heat resistance while the specific structural modifications enable compatibility and controlled melting behavior for low temperature fixing.
2Temperature
If a crystalline polyester resin having low melt viscosity is used as a binder resin, then low temperature fixability is improved, but document off-set resistance deteriorates
Solution Approach 1:
The composite binder resin system combines amorphous resin with urethane modified crystalline resin to achieve both low temperature fixability and document off-set resistance. The crystalline component provides structural integrity and resistance to offset, while the amorphous component enables low temperature melting for fixing.
Solution Approach 2:
The urethane modification of the crystalline resin changes its viscoelastic properties and melting characteristics, allowing it to maintain document off-set resistance while enabling low temperature fixing through controlled softening behavior.
3Temperature
If a crystalline polyester resin having low melt viscosity is used as a binder resin, then low temperature fixability is improved, but glossiness of fixed image increases excessively
Solution Approach 1:
The composite binder resin system controls glossiness by combining amorphous and crystalline components in specific proportions. The crystalline urethane modified resin provides matte characteristics that counterbalance the glossiness tendency of low viscosity resins, while still enabling low temperature fixing.
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 and sufficient document offset resistance while preventing excessive glossiness of the fixed image, through the combination of amorphous and urethane modified crystalline resins, which maintain sharp melting properties and viscoelasticity.
Implementation Method 1
a melting point of the urethane modified crystalline resin is TmC
Implementation Method 2
an endothermic amount of the toner for electrostatic charge image development, which is based on an endothermic peak derived from the urethane modified crystalline resin during a first temperature increasing process for increasing the temperature from 0° C. to 200° C. in differential scanning calorimetry, is ΔH1 (J/g)
Implementation Method 3
a glass transition point of the amorphous resin is TgA
Implementation Method 4
the urethane modified crystalline resin being non-compatible with the amorphous resin
Data Source
AI summary
To provide a toner for electrostatic charge image development which allows obtainment of excellent low temperature fixability and a document off-set resistance sufficiently and also inhibition of an excessive increase in glossiness of a formed fixed image, and a method for manufacturing the same.The toner for electrostatic charge image development includes toner particles containing a binder resin, a colorant, and a releasing agent, in which the binder resin contains at least an amorphous resin and an urethane modified crystalline resin including a crystalline polymer segment and an urethane polymer segment bound to each other, the urethane modified crystalline resin being non-compatible with the amorphous resin, and the amount of ionic dissociating group of the urethane modified crystalline resin is 5 to 20 mgKOH/g.