Crystalline Amorphous Polyester Toner Fixing
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Solution Overview
Problem
Current toners for electrophotography and electrostatic printing face challenges in achieving both low-temperature fixability and heat-resistant storage stability, particularly in high-speed and energy-saving image forming processes, with existing polyester resins failing to meet stringent requirements for energy efficiency and image quality.
Innovation Solution
A toner formulation involving a combination of crystalline and amorphous polyester resins, where the crystalline polyester resin is dispersed in an aqueous medium with an organic solvent, and the organic solvent is removed to create a dispersion, enhancing low-temperature fixability and heat-resistant storage stability by controlling the endothermic peak temperatures and molecular weight distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If polyester resin is used as toner binder to reduce fixing temperature, then low-temperature fixability is improved, but storage stability deteriorates due to blocking
Solution Approach 1:
The patent modifies the molecular weight distribution parameters of the polyester resin, specifically controlling the ratio of low molecular weight components (5-20 parts per 100 parts total) to achieve optimal balance between low-temperature fixability and storage stability
Solution Approach 2:
The patent creates a composite resin system by combining polyester resin with specific additives and controlling the molecular weight distribution to form a multi-component binder system that simultaneously provides low-temperature fixability and hot offset resistance
2Use of energy by stationary object
If heater power is reduced during sleep mode to save energy, then electricity consumption is reduced, but fixing readiness time increases
Solution Approach 1:
The patent changes the thermal properties of the toner by controlling polyester resin molecular weight distribution, enabling the toner to be fixed at lower temperatures, which allows the heater to operate at reduced power while maintaining fixing capability and reducing both energy consumption and warm-up time
3Use of energy by stationary object
If fixing temperature is reduced to save energy, then electricity consumption is reduced, but hot offset resistance deteriorates
Solution Approach 1:
The patent optimizes the molecular weight distribution parameters of the polyester resin, controlling the ratio of low molecular weight components (5-20 parts per 100 parts) to achieve sufficient melt flow at low temperatures for fixing while maintaining adequate viscosity at storage temperatures to prevent hot offset
Solution Approach 2:
The patent uses low molecular weight polyester resin components that provide temporary low-temperature flowability during fixing, which then crosslink or stabilize after fixation to provide long-term hot offset resistance
4Temperature
If toner is made fixable at lower temperatures for energy saving, then fixing temperature is reduced, but image quality and durability deteriorate
Solution Approach 1:
The patent precisely controls the molecular weight distribution of the polyester resin, maintaining a specific ratio of low molecular weight components (5-20 parts per 100 parts) to ensure proper melting and flow at low temperatures during fixing, while the resin composition provides sufficient adhesion and durability for high-quality images
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-definition images with extended durability and improved heat-resistant storage stability, reducing electricity consumption and preventing hot offset, while maintaining low-temperature fixability, thus addressing the limitations of previous toner technologies.
Implementation Method 1
the crystalline polyester resin has a sharp endothermic curve in which an endothermic peak exists within a temperature range of from 60°C to 80°C
Implementation Method 2
the crystalline polyester resin has a sharp endothermic curve in which an endothermic peak exists within a temperature range of from 60°C to 80°C
Implementation Method 3
removing the organic solvent from the O/W dispersion
Data Source
AI summary
A toner comprising a colorant, a crystalline polyester resin, and an amorphous polyester resin, in which the crystalline polyester resin satisfies the following relations: 60≤T2-cp<80 T2-cs2-T2-cp<10 T2-cp-T2-cs1<10 wherein (T2-cp) (°C) represents an endothermic peak temperature, (T2-cs1) (°C) represents a first endothermic shoulder temperature, and (T2-cs2) (°C) represents a second endothermic shoulder temperature, each determined from a second heating in a differential scanning calorimetry.