Electrostatic Toner Glass Transition Control
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Solution Overview
Problem
Existing toners with controlled glass transition temperatures for low-temperature fixability often compromise on color forming properties, leading to dull images and increased image defects due to segment orientation and crystallization during heating.
Innovation Solution
Developing an electrostatic image developing toner with a specific range of glass transition temperatures (Tg1: 58°C to 68°C and Tg1−Tg2: 20°C to 40°C) to minimize segment orientation and crystallization, ensuring high color forming properties and improved heat resistance, which reduces image defects and aggregation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the glass transition temperature of the toner is controlled in a specific range to achieve low-temperature fixability, then low-temperature fixability is improved, but color forming properties deteriorate due to segment orientation and crystallization during heating
Solution Approach 1:
The patent applies parameter changes by precisely controlling the glass transition temperature (Tg1: 58-68°C) and the temperature difference between glass transition points (Tg1-Tg2: 20-40°C) through specific heating and cooling processes. This parameter control enables the toner to achieve both low-temperature fixability and high color forming properties by optimizing the thermal behavior of the binder resin during image formation.
Solution Approach 2:
The patent employs preliminary action through the specific heating and cooling treatment process applied before toner production. The binder resin is heated to melt and aggregated particles are formed, then cooled at controlled rates (first cooling at 10-50°C/min, second cooling at 50-150°C/min) to establish the desired glass transition temperature characteristics. This preliminary thermal processing ensures the toner achieves both low-temperature fixability and excellent color forming properties.
2Reliability
If the glass transition temperature is controlled for low-temperature fixability, then fixability at lower temperatures is improved, but image defects increase due to segment orientation and crystallization
Solution Approach 1:
The patent uses parameter changes to control the glass transition temperature (Tg1: 58-68°C) and the temperature difference (Tg1-Tg2: 20-40°C) to prevent segment orientation and crystallization during heating. This parameter optimization allows the toner to maintain reliability at low temperatures while minimizing image defects such as dullness and granularity.
Solution Approach 2:
The patent converts the potentially harmful effect of crystallization and segment orientation into a benefit by controlling the glass transition temperature and cooling rates. The controlled crystallization process, guided by the specific Tg1 and Tg1-Tg2 ranges, actually prevents harmful segment orientation while promoting beneficial crystalline structure formation that enhances both fixability and image quality.
3Ease of manufacture
If the glass transition temperature is controlled to minimize segment orientation, then color forming properties are improved, but heat resistance may be compromised
Solution Approach 1:
The patent applies parameter changes by establishing specific glass transition temperature ranges (Tg1: 58-68°C, Tg1-Tg2: 20-40°C) that balance color forming properties with heat resistance. The controlled thermal history and cooling rates ensure the binder resin maintains appropriate crystallinity and molecular mobility to resist heat while preserving excellent color forming characteristics.
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 color forming properties while maintaining low-temperature fixability, reducing image defects and aggregation, and enhancing resistance to mechanical and thermal stress.
Implementation Method 1
In a differential scanning calorimetry curve of the toner particles, Tg1 is 58° C. or more and 68° C. or less, and Tg1-Tg2 is 20° C. or more and 40° C. or less
Data Source
AI summary
An electrostatic image developing toner includes toner particles containing a binder resin. In a differential scanning calorimetry curve of the toner particles, Tg1 is 58° C. or more and 68° C. or less, and Tg1−Tg2 is 20° C. or more and 40° C. or less, where Tg1 is a lowest onset temperature in an endothermic change during a first temperature increase, and Tg2 is a lowest onset temperature in an endothermic change during a second temperature increase.