Color Toner Preparation via In Situ Emulsion Polymerization
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Solution Overview
Problem
Conventional methods for preparing color toner result in poor resolution, uneven color distribution, and difficulty in recycling and cleaning due to issues with particle size, shape, and wax distribution, leading to high waste rates and sticking to photoreceptors.
Innovation Solution
A method involving in situ emulsion polymerization to create anionic and cationic polymer composite emulsions with nano-silica as core, agglutination using an impinging stream mixer, and subsequent filtering and drying to produce a non-spherical toner with uniform size and shape, eliminating the need for excess wax and improving resolution and recyclability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional mechanical grinding and gas flow grinding methods are used to prepare color toner, then the particle size can be reduced to about 10 μm, but the resolution is low and the color is poor due to big and non-uniform toner particles
Solution Approach 1:
The patent changes the fundamental preparation method from mechanical grinding to suspension polymerization, transforming the process parameters from low-temperature mechanical force to controlled chemical polymerization conditions. This enables precise control of particle size distribution and shape, producing uniform toner particles that improve printing resolution and color quality
Solution Approach 2:
The patent utilizes the phase transition of monomers to polymer particles during suspension polymerization. By controlling the polymerization process, monomers transform into solid polymer particles with controlled size and shape, eliminating the need for subsequent mechanical grinding and achieving uniform toner particles directly
2Ease of operation
If suspension polymerization method is used to control toner particle size, then the flow and charging properties are improved, but the toner has a wide particle size distribution resulting in low resolution and poor color
Solution Approach 1:
The patent optimizes suspension polymerization parameters including monomer concentration, surfactant dosage, polymerization temperature, and stirring speed. These parameter adjustments narrow the particle size distribution while maintaining good flow and charging properties, resolving the contradiction between operational ease and manufacturing precision
3Manufacturing precision
If emulsion polymerization/co-flocculation method is used to narrow particle size to 5 μm or nano level, then the resolution and color are improved, but the resin particles and colorant particles are hard to disperse uniformly and bind to each other
Solution Approach 1:
The patent performs preliminary dispersion of colorant in the polymerization system before polymer particles form. This ensures uniform distribution of colorant throughout the reaction medium, preventing aggregation and ensuring homogeneous color in the final toner product
Solution Approach 2:
The patent uses surfactants as intermediaries to facilitate uniform dispersion and binding of resin and colorant particles. The surfactant molecules adsorb onto both polymer and colorant surfaces, acting as a bridge that promotes homogeneous distribution and strong binding between the two components
4Reliability
If a large amount of wax is added to improve anti-partial printing properties, then the anti-partial printing is improved, but the wax transfers to the surface of toner polluting the carrier and developing sleeve
Solution Approach 1:
The patent changes the wax addition strategy from large amounts to optimized small amounts. By adjusting the polymerization parameters and using controlled amounts of wax, the patent achieves sufficient anti-partial printing properties while minimizing wax transfer and pollution of carrier and developing sleeve
5Reliability
If excess wax is added to improve anti-partial printing, then the anti-partial printing is enhanced, but the pigment distribution in toner becomes uneven resulting in poor printing and copying quality
Solution Approach 1:
The patent optimizes the wax concentration parameter to an appropriate level, avoiding excess wax addition. By controlling the wax amount and polymerization conditions, the patent maintains good anti-partial printing properties while ensuring uniform pigment distribution throughout the toner particles
Solution Approach 2:
The patent ensures that wax is uniformly distributed at the molecular level within the polymer matrix rather than forming aggregates. This local uniformity of wax distribution prevents pigment aggregation and maintains homogeneous pigment dispersion, achieving both anti-partial printing and good print quality
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 produces toner with high resolution, uniform color, and improved recyclability, reducing waste and preventing sticking to photoreceptors, while maintaining excellent printing and copying quality.
Implementation Method 1
agglutinating the anionic polymer composite emulsion comprising wax and the cationic polymer composite emulsion comprising colorant
Implementation Method 2
the impinging stream mixer makes currents collide to form a high frequency eddy current so that different materials are mixed completely
Data Source
AI summary
A method of preparing a color toner by: a) preparing an anionic polymer composite emulsion comprising wax with a wax particle and nanosilica as core by in situ emulsion polymerization; b) preparing a cationic polymer composite emulsion comprising colorant with a colorant and nanosilica as core by in situ emulsion polymerization; c) agglutinating the anionic polymer composite emulsion comprising wax and the cationic polymer composite emulsion comprising colorant; and d) filtering, washing, and drying the product obtained in c). The color toner prepared by this method. The color toner has high development density, high resolution, low bottom ash, low waste rate, and low consumption, and is easy to recover and recycle.