Toner Production via Supercritical Fluid Polymerization
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Solution Overview
Problem
Current toner production processes for electrophotography face challenges in achieving uniform particle shape, stable charging properties, and environmental sustainability, with issues such as hydrophilic toner surfaces, broad particle size distributions, and high energy and waste generation.
Innovation Solution
A toner production process using supercritical or subcritical fluids for polymerizing radically polymerizable monomers, resulting in toner particles with hydrophobic surfaces and sharp particle size distributions, which reduces waste and energy consumption while improving charging properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional kneading and pulverization methods are used for toner production, then the process is simple and energy-efficient, but the toner particles have amorphous shapes with randomly-sized cross sections and poor uniformity
Solution Approach 1:
The invention changes the physical state of the polymerization medium from conventional aqueous or organic solvents to supercritical or subcritical fluids. This parameter change enables precise control over particle formation, resulting in spherical toner particles with uniform cross-sections while maintaining manufacturing feasibility through established supercritical fluid technology
Solution Approach 2:
The invention utilizes phase transitions of supercritical or subcritical fluids to control toner particle formation. By controlling the phase state of the polymerization medium, the process achieves uniform spherical particles through controlled nucleation and growth, then transitions to the next phase for particle separation and collection
2Adaptability or versatility
If additives are added to toner during pulverization, then the toner can be colored and functionalized, but the additives migrate to particle surfaces during pulverization, reducing toner characteristics
Solution Approach 1:
The invention incorporates additives into the toner formulation before polymerization occurs, rather than adding them during pulverization. This preliminary action ensures uniform distribution of coloring materials, releasing agents, and charge-controlling agents throughout the toner particles, preventing migration to surfaces and maintaining stable charging properties
Solution Approach 2:
The invention changes the polymerization conditions to supercritical or subcritical fluid states, which prevents additive migration to particle surfaces. The unique physical properties of supercritical fluids allow additives to remain uniformly distributed within the polymer matrix, maintaining toner characteristics while providing necessary functionality
3Ease of manufacture
If toner is produced in water or hydrophilic medium, then the polymerization process is simple, but the toner surface becomes hydrophilic, reducing charging properties and environmental characteristics
Solution Approach 1:
The invention changes the polymerization medium from hydrophilic (water-based) to supercritical or subcritical fluids with different polarity characteristics. This parameter change results in hydrophobic toner surfaces that maintain stable charging properties and environmental characteristics while keeping the polymerization process simple and efficient
4Manufacturing precision
If polymerization methods are used for toner production, then spherical particles with smaller diameters and narrower particle size distribution are produced, but a large amount of waste solution is generated and high energy is required for drying
Solution Approach 1:
The invention utilizes phase transitions of supercritical or subcritical fluids to eliminate the need for separate drying steps. The fluid is transitioned from supercritical/subcritical state to gaseous or liquid state, allowing direct separation of toner particles without energy-intensive drying operations, while maintaining narrow particle size distribution
Solution Approach 2:
The invention recovers and reuses the supercritical or subcritical fluid in the polymerization process, minimizing waste solution generation. The fluid is recovered from the reaction mixture and recycled, reducing both energy consumption for drying and environmental impact, while maintaining high particle size uniformity
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 process produces toners with excellent charging properties, environmental stability, and high-definition images, while minimizing waste and energy use, and allows for the use of a broader range of materials, enhancing the overall efficiency and quality of the toner production.
Implementation Method 1
polymerizing radically polymerizable monomers in at least one of a supercritical fluid and a subcritical fluid
Implementation Method 2
using supercritical or subcritical fluids for polymerizing radically polymerizable monomers
Data Source
AI summary
To provide a toner production process in which at least radically polymerizable monomers are polymerized in at least one of a supercritical fluid and a subcritical fluid to thereby produce toner particles, wherein a polymer of the radically polymerizable monomers is insoluble in at least one of the supercritical fluid and the subcritical fluid.