Decolorable Toner Production via Reactive Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing erasable toner face challenges such as decreased color density and decoloring reaction rate due to component interactions during melt-kneading, and issues with fine powder release causing image defects, especially when using microencapsulated color materials.
Innovation Solution
A decolorable toner is produced by aggregating color material fine particles with a binder resin having a carboxyl group, followed by treatment with a compound containing a carbodiimide or epoxy group, which enhances fusion and reduces fine powder release, improving color density and decoloring efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If melt-kneading method is used to produce erasable toner, then components can be mixed thoroughly, but color density and decoloring reaction rate decrease due to component reactions
Solution Approach 1:
The patent divides the toner into separate components: microencapsulated color materials and binder resin particles. These segmented components are then aggregated together, preventing premature reactions while maintaining uniform distribution. The segmentation allows each component to retain its functional integrity until the toner is applied to the photoreceptor.
Solution Approach 2:
The patent uses microencapsulation to nest the color material (color-forming agent, color-developing agent, and decoloring agent) within protective capsules. This nested structure prevents interaction between components during storage and handling, while allowing controlled interaction when the toner is applied and heated during the imaging process.
2Ease of manufacture
If wet process is used to aggregate fine particles, then mechanical shearing and thermal history are avoided, but fine powder release causes image defects
Solution Approach 1:
The patent creates a composite toner structure combining microencapsulated color materials with binder resin particles. The binder resin forms a matrix that holds the microencapsulated color materials together, preventing fine powder release while maintaining the benefits of the wet process (avoidance of mechanical shearing and excessive thermal history).
Solution Approach 2:
The binder resin acts as an intermediary material that facilitates the aggregation of fine particles without causing them to react prematurely. The binder resin particles provide a carrying medium that allows microencapsulated color materials to be aggregated through controlled processes while preventing direct contact and reaction between the color material components until application.
3Stability of the object's composition
If microencapsulated color materials are used, then component reactions are prevented during storage, but fine powder release increases causing fogging
Solution Approach 1:
The patent combines microencapsulated color materials with binder resin to create a composite toner system. The binder resin matrix provides structural integrity that prevents the microencapsulated color materials from releasing fine powder during storage and handling, while maintaining the stability benefits of microencapsulation.
Solution Approach 2:
The patent uses the microencapsulation shell as a protective thin film that surrounds the color material. This shell prevents direct exposure of the color material to the environment, preventing fine powder release while maintaining component stability. The binder resin additional provides a matrix that further stabilizes the structure.
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 solution effectively suppresses fine powder generation and enhances the decoloring process, maintaining high image density and stability, while ensuring low-temperature fixability and erasability.
Implementation Method 1
surfaces of the toner particles have been treated with a compound having a carbodiimide group or an epoxy group reactive with the carboxyl group of the binder resin
Implementation Method 2
aggregating dispersed fine particles of color material comprising at least a color-forming compound, a color-developing agent and a decoloring agent with dispersed fine particles comprising at least a binder resin having a carboxyl group to form aggregate particles, then adding a compound having a carbodiimide group or an epoxy group reactive with the carboxyl group of the binder resin, and thereafter fusing the aggregate particles, respectively in an aqueous medium
Data Source
AI summary
Disclosed is a decolorable toner produced by aggregating dispersed fine particles of a color material containing at least a color-forming compound, a color-developing agent and a decoloring agent with dispersed fine particles containing at least a binder resin having a carboxyl group, then adding a compound having a carbodiimide group or an epoxy group reactive with the carboxyl group of the binder resin, and thereafter fusing the aggregate particles, respectively in an aqueous medium. The thus obtained decolorable toner can suppress the generation of fine powder by the release of erasable color material fine particles from the toner particles.