Electrostatic Toner With Polyester-Mediated Carbon Black Dispersion
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Solution Overview
Problem
Existing toners fail to achieve high image density in printed matters due to the aggregation of carbon black with high BET specific surface area during the production process, leading to insufficient dispersion and image quality.
Innovation Solution
A toner formulation using an amorphous polyester resin with a specific ester group concentration and carbon black with a high BET specific surface area, which interacts through hydrogen bonding to suppress aggregation and ensure homogeneous dispersion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If carbon black with high BET specific surface area is used to increase coloring power, then image density is improved, but carbon black aggregation occurs during production leading to poor dispersion
Solution Approach 1:
The patent introduces a binder resin as an intermediary substance between carbon black particles. The binder resin contains specific functional groups that interact with carbon black surface groups through hydrogen bonding, acting as a mediator to prevent direct carbon black aggregation while maintaining high image density. This resolves the contradiction by providing a third component that facilitates both high coloring power and homogeneous dispersion.
Solution Approach 2:
The patent changes the chemical parameter of the binder resin by specifying functional groups with particular hydrogen bonding capabilities. By adjusting the chemical composition and bonding characteristics of the binder resin, the patent optimizes the interaction with carbon black to achieve both high image density and homogeneous dispersion, resolving the contradiction through parameter optimization.
2Manufacturing precision
If carbon black particles are closely packed to increase coloring power, then image density is improved, but particle cohesive force increases making dispersion difficult
Solution Approach 1:
The binder resin serves as an intermediary that reduces the direct cohesive forces between carbon black particles. By introducing this third component with specific hydrogen bonding characteristics, the patent enables close packing for high image density while the binder resin prevents excessive aggregation, making dispersion easier during manufacturing.
Solution Approach 2:
The patent creates a composite material system combining carbon black and binder resin with specific chemical interactions. This composite approach allows the carbon black to maintain high packing density for image quality while the binder resin matrix provides dispersion assistance, resolving the contradiction between coloring power and dispersion ease.
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 toner achieves a printed matter with high image density by effectively dispersing carbon black, enhancing the image quality and stability.
Implementation Method 1
the binder resin contains an amorphous polyester resin A having an ester group concentration of 5.0 mmol/g or more and 15.0 mmol/g or less, and the colorant contains carbon black having a BET specific surface area of 200 m2/or more and 350 m2/g or less
Data Source
AI summary
The present invention relates to a toner for electrostatic image development, the toner containing a binder resin and a colorant, in which the binder resin contains an amorphous polyester resin A having an ester group concentration of 5.0 mmol/g or more and 15.0 mmol/g or less, and the colorant contains carbon black having a BET specific surface area of 200 m2/g or more.