Core-Shell Emulsion Aggregation Toner for Triboelectric Charging

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Solution Overview

Problem

Existing toners face challenges with improved triboelectric charging performance, reduced dielectric loss, enhanced image quality, reduced mottle, and increased transfer efficiency, while maintaining high colorant concentrations and cost-effectiveness.

Innovation Solution

The development of toners with a core-shell structure, where the core comprises a first resin and a first conductive colorant, and the shell comprises a second resin and a second conductive colorant, utilizing specific polyester resins and emulsion aggregation processes to achieve desired particle size and morphology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional toner compositions are used, then manufacturing cost is reduced, but triboelectric charging performance deteriorates

Engineering Contradiction:

Improvetriboelectric charging performanceVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The toner particle is divided into a core and a shell, where the core contains the resin and colorant, and the shell contains the conductive colorant. This segmentation allows the conductive components to be concentrated in the shell, improving triboelectric charging performance while using minimal amounts of expensive conductive materials, thus maintaining cost-effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The conductive colorant is localized specifically in the shell region of the toner particle rather than being distributed throughout the entire particle. This local concentration of conductive properties enhances triboelectric charging at the particle surface where it is most needed, while reducing the overall amount of conductive material required.

Inventive Principle:

Principle #3Local quality

2Loss of energy

If conventional toner compositions are used, then manufacturing cost is reduced, but dielectric loss increases

Engineering Contradiction:

Improvedielectric lossVSAvoidmanufacturing cost

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

By segmenting the toner particle into core and shell regions, the conductive colorant is concentrated in the shell, creating a structure that reduces dielectric loss through improved charge distribution while minimizing the use of expensive conductive materials.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The toner particle combines resin, colorant, and conductive colorant in a composite structure where the conductive colorant in the shell forms a conductive network that reduces dielectric loss, while the overall composite maintains cost-effectiveness through optimized material distribution.

Inventive Principle:

Principle #40Composite materials

3Manufacturing precision

If conventional toner compositions are used, then manufacturing cost is reduced, but image quality deteriorates

Engineering Contradiction:

Improveimage qualityVSAvoidmanufacturing cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The core-shell segmentation provides a controlled structure where the shell with conductive colorant ensures consistent charge distribution and reduced mottle, leading to improved image quality. The segmentation also enables precise control over particle morphology during the emulsion aggregation process.

Inventive Principle:

Principle #1Segmentation

4Productivity

If conventional toner compositions are used, then manufacturing cost is reduced, but transfer efficiency deteriorates

Engineering Contradiction:

Improvetransfer efficiencyVSAvoidmanufacturing cost

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The core-shell structure segments the functional components, with the conductive colorant concentrated in the shell, which enhances transfer efficiency through improved charge distribution and reduced mottle during the transfer process, while maintaining cost-effectiveness.

Inventive Principle:

Principle #1Segmentation

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 toners exhibit improved triboelectric charging characteristics, reduced dielectric loss, enhanced image quality, and increased transfer efficiency, while maintaining high colorant concentrations and being produced at a reduced cost.

Implementation Method 1

improved triboelectric charging characteristics

Methodology Applied

Scientific EffectTriboelectric charging: Triboelectric Effect

Implementation Method 2

reduced dielectric loss

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS8703377B2Emulsion aggregation toner compositions

Publication Date: 2014.04.22 XEROX CORP

AI summary

Disclosed is a toner which comprises particles comprising: (a) a core comprising: (1) a first resin; and (2) a first conductive colorant; and (b) a shell comprising: (1) a second resin; and (2) a second conductive colorant.