Core-Shell Suspension Polymerization Toner for Uniform Charge
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Solution Overview
Problem
Conventional toner manufacturing methods, such as mechanical pulverizing and suspension polymerization, face challenges in achieving uniform charge distribution and retention, spherical shape, and low-temperature fixation, leading to inefficient use of charge control agents and poor storage stability.
Innovation Solution
A suspension polymerization method is employed to create core-shell toner particles with a rigid shell layer coated on a soft core, using a resin-type charge control agent for uniform surface coverage, achieving a high charge density and regular shape, and incorporating a specific weight ratio and thickness of the shell layer for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical pulverizing method is used to manufacture toner, then the production process is simple, but the toner particles have irregular shape and non-uniform charge distribution
Solution Approach 1:
The invention segments the toner manufacturing process into two distinct stages: first forming toner particles through suspension polymerization, then coating CCA on the particle surfaces. This segmentation allows each stage to be optimized independently, achieving both spherical particle formation and uniform surface charge distribution.
Solution Approach 2:
The invention performs preliminary action by pre-forming spherical toner particles through suspension polymerization before coating the CCA. This ensures that the particle morphology is established before charge control agent application, enabling uniform CCA distribution on the particle surfaces.
2Ease of manufacture
If CCA is dispersed in the central region of toner particles, then the polymerization process is simplified, but the charge density on the surface is insufficient
Solution Approach 1:
The invention extracts the CCA from the bulk polymerization process and applies it separately to the particle surfaces through coating. This separation ensures that CCA is concentrated on the surface where it is needed for charging, rather than being distributed throughout the particle interior.
Solution Approach 2:
The invention applies local quality by concentrating CCA specifically on the surface region of toner particles rather than distributing it uniformly throughout the bulk. This localized application maximizes surface charge density while maintaining manufacturing efficiency.
3Shape
If conventional suspension polymerization is used, then the toner particles achieve good sphericity, but the CCA distribution is non-uniform and charge retention is poor
Solution Approach 1:
The invention performs preliminary action by first forming spherical particles through suspension polymerization, then subsequently coating CCA on the formed particles. This two-step approach ensures spherical morphology is established before CCA application, enabling uniform surface distribution.
Solution Approach 2:
The invention segments the manufacturing process into particle formation and CCA coating as separate operations. This allows optimal conditions for each process to be maintained independently, achieving both spherical shape and uniform surface charge distribution.
4Shape
If high-speed collision is used for spheronization, then the toner particles become more spherical, but the energy consumption increases and equipment requirements are high
Solution Approach 1:
The invention performs preliminary action by forming spherical particles directly during the polymerization process through suspension polymerization, eliminating the need for subsequent high-speed collision spheronization. This approach achieves spherical morphology with much lower energy consumption.
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 results in toner particles with high electrification, excellent transfer printing efficiency, low-temperature fixation, and improved storage stability, ensuring high image quality and reduced surface pollution on the photosensitive drum.
Implementation Method 1
mixing suspension dispersion liquid of soft toner core particles with shell monomer emulsion and CCA dispersion liquid, and carrying out a polymerization reaction to form rigid shell layers with dense charges
Implementation Method 2
Charges of the toner can be generated by the friction between the blade and the CCA on the surface of the toner
Implementation Method 3
The toner charged by a developing roller and a blade can develop the electrostatic latent image on the surface of the photosensitive drum
Implementation Method 4
the image on the surface photosensitive drum can be transferred and printed on the paper. Then we will get the desired printed image fixed by a heating roller and a pressure roller
Data Source
AI summary
Suspension polymerization toner of a core-shell structure with dense charges comprises core-shell composite particles prepared by mixing suspension dispersion liquid of toner core particles with shell monomer emulsion and resin-type CCA dispersion liquid, and carrying out a polymerization reaction to form rigid shell layers with dense charges coated on the soft toner core particles. A preparation method thereof comprises: mixing a low-Tg monomer oil phase forming toner core particles with aqueous dispersion liquid, carrying out a heating polymerization reaction after suspension granulation to convert monomer oil droplet particles to polymer particles, and obtaining soft toner core particles; adding a high-Tg shell monomer forming rigid shell layers into water containing a surfactant to form emulsion, adding the emulsion and CCA dispersion liquid into suspension dispersion liquid of the soft toner core particles for second polymerization after mixing, and cleaning, filtering, drying and performing additive treatment.