Toner Production Cooling Rate Control for Particle Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing toners for electrostatic charge images often result in coarse particles due to the fusion of releasing agents, leading to color spots in the images formed, as the releasing agents cause toner particles to fuse together during the aggregation and coalescence process, which existing methods fail to adequately suppress.
Innovation Solution
A method involving the aggregation of resin and releasing agent particles to form aggregated particles, followed by heating and fusing these particles, and then cooling them to a temperature below the endothermic peak onset temperature of the releasing agent at a controlled rate to prevent excessive fusion and generate toner particles with improved shape and size uniformity, thereby reducing color spots.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If releasing agent particles are aggregated with resin particles to form aggregated particles, then the toner production process can proceed, but the releasing agents cause toner particles to fuse together forming coarse particles
Solution Approach 1:
The patent applies parameter changes by precisely controlling the cooling rate of the aggregated particles during the fusion process. By adjusting the cooling rate to be within a specific range (0.1°C/min to 10°C/min), the patent prevents excessive fusion of releasing agent particles while still achieving proper toner particle formation, thus resolving the contradiction between manufacturing feasibility and particle size uniformity.
Solution Approach 2:
The patent employs dynamics by making the cooling rate adjustable and variable during the fusion process. The cooling rate is not fixed but dynamically controlled to optimize the fusion behavior of releasing agent particles, allowing the process to adapt to different material properties and achieve uniform particle size distribution.
2Productivity
If the cooling rate is increased to speed up the production process, then productivity improves, but the releasing agents cause excessive fusion and coarse particles
Solution Approach 1:
The patent resolves this contradiction by establishing an optimal cooling rate range (0.1°C/min to 10°C/min) that balances productivity and particle size uniformity. This parameter optimization allows the process to achieve both efficient production and high manufacturing precision by preventing excessive fusion while maintaining adequate production speed.
3Manufacturing precision
If the cooling rate is decreased to prevent releasing agent fusion, then particle uniformity improves, but the production time increases
Solution Approach 1:
The patent addresses this contradiction by optimizing the cooling rate to a specific range (0.1°C/min to 10°C/min) that achieves particle uniformity without excessive production time. This parameter optimization prevents releasing agent fusion while maintaining reasonable production cycles, balancing quality and time efficiency.
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 method effectively suppresses the occurrence of color spots in the images by controlling the cooling rate and temperature of the toner dispersion, resulting in toner particles with enhanced shape controllability and image quality.
Implementation Method 1
heating the aggregated particles to a temperature equal to or higher than a melting point of the crystalline resin
Implementation Method 2
cooling the aggregated particles to a temperature equal to or lower than a temperature 30° C. lower than an endothermic peak onset temperature derived from a releasing agent
Data Source
AI summary
A method for producing a toner for developing an electrostatic charge image includes aggregating at least resin particles and releasing agent particles contained in a dispersion to form aggregated particles; heating and fusing the aggregated particles to prepare a dispersion containing fused particles; and cooling the dispersion containing the fused particles to a temperature equal to or lower than a temperature 30° C. lower than an endothermic peak onset temperature derived from a releasing agent that constitutes the releasing agent particles, in which, in the cooling, the dispersion is cooled at a rate of 30° C./min or more and 130° C./min or less.