Electrophotography Toner Production via Polymer Aggregation
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Solution Overview
Problem
Chemical prepared toners for electrophotography face challenges in achieving high image density due to poor colorant dispersibility, leading to increased colorant usage and complex production processes.
Innovation Solution
A process involving the mixing of colorant-containing polymer particles with resin particles, where the polymer contains constitutional units from salt-forming group-containing and aromatic ring-containing monomers, enhances dispersibility and image density, allowing for reduced colorant amounts while maintaining high image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemical prepared toners are used to achieve small particle size and narrow particle size distribution, then particle size uniformity is improved, but colorant dispersibility deteriorates
Solution Approach 1:
The invention applies preliminary action by pre-forming colorant-containing polymer particles with controlled size and composition before mixing with resin particles. This pre-preparation ensures that colorant is already incorporated in the polymer matrix in a dispersed state, eliminating the need for subsequent dispersion steps and preventing aggregation during toner formation.
Solution Approach 2:
The invention uses composite materials by creating colorant-containing polymer particles that combine colorant with specific polymer matrices. These composite particles serve as building blocks that maintain both colorant dispersion and particle size uniformity when aggregated with resin particles to form the final toner.
2Quantity of substance
If amount of colorant is increased to compensate for poor dispersibility, then image density is improved, but productivity deteriorates
Solution Approach 1:
By preliminarily incorporating colorant into polymer particles during polymerization, the invention achieves effective colorant distribution without needing to increase overall colorant content. This preliminary incorporation ensures that each polymer particle contains uniformly dispersed colorant, maximizing image density with minimal colorant usage and maintaining high productivity.
3Quantity of substance
If kneaded material is emulsified to improve colorant dispersibility, then colorant dispersibility is improved, but production process complexity increases
Solution Approach 1:
The invention performs the dispersion action preliminarily during the polymerization step itself, where colorant is incorporated into forming polymer particles. This eliminates the need for separate emulsification or dispersion steps that would increase process complexity, as the colorant is already dispersed when particles are formed.
Solution Approach 2:
The invention merges the polymerization process with colorant incorporation into a single step. By combining these operations, the colorant-containing polymer particles are formed directly without requiring separate dispersion or emulsification steps, thereby simplifying the overall production process while achieving good colorant dispersibility.
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 significantly improves colorant dispersibility and image density in toners, enabling high-quality images with lower colorant usage and simplified production.
Implementation Method 1
mixing a dispersion of colorant-containing polymer particles with a dispersion of resin particles containing substantially no colorant to aggregate the colorant-containing polymer particles and the resin particles
Data Source
AI summary
The present invention relates to a process for producing a toner for electrophotography which is excellent in dispersibility of a colorant in the toner and capable of considerably improving an image density, as well as a toner for electrophotography which is produced by the process. There is provided a process for producing a toner for electrophotography which includes the step of mixing a dispersion of colorant-containing polymer particles with a dispersion of resin particles containing substantially no colorant to aggregate the colorant-containing polymer particles and the resin particles, wherein the polymer contains a constitutional unit derived from a salt-forming group-containing monomer (a) and a constitutional unit derived from an aromatic ring-containing monomer (b).