Toner Particle Domain Distribution for Rubbing Gloss

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Electrostatic image developing toners with high toner deposition density often experience a reduction in image gloss when rubbed, due to inadequate adhesion between toner particles and excessive release agent seepage, leading to inconsistencies in image quality.

Innovation Solution

The development of an electrostatic image developing toner with specific domain structures and release agent distribution, where release agent domains are strategically positioned within the toner particles to enhance adhesion while maintaining ease of detachment, using toner particles with domains that satisfy conditions related to diameter, circularity, and depth within the toner particle, and a release agent with a melting temperature between 65°C and 95°C, such as an ester wax.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high toner deposition density is used, then image coverage and productivity are improved, but image gloss is reduced due to excessive release agent seepage

Engineering Contradiction:
Improvetoner deposition densityVSAvoidimage gloss
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The release agent domains are positioned at specific locations within the toner particle (at a distance of 0.10 μm or more from the surface) rather than being uniformly distributed. This local positioning strategy allows the release agent to be available for detachment when needed while preventing excessive seepage that would harm image gloss, thus resolving the contradiction between high deposition density and image quality.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the physical parameters of the release agent domains, specifically their size (0.03-2.00 μm diameter) and position (distance from particle surface), to optimize both adhesion and detachment properties. By controlling these parameters, the toner achieves high deposition density while maintaining image gloss.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If release agent content is increased to improve detachment ease, then toner particle detachment is improved, but adhesion between toner particles deteriorates

Engineering Contradiction:
Improvedetachment easeVSAvoidadhesion between toner particles
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The release agent is localized in specific domains positioned away from the particle surface (0.10 μm or more distance), creating regions of different functionality within the toner particle. This local concentration strategy provides sufficient release agent for detachment while maintaining overall particle adhesion through the binder resin structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The toner particle is designed as a composite structure containing binder resin, colorant, and release agent domains with specific properties. This composite approach allows the release agent domains to provide detachment ease while the binder resin matrix maintains adhesion between particles, resolving the contradiction between these two opposing requirements.

Inventive Principle:
Principle #40Composite materials

3Ease of operation

If release agent domains are positioned closer to the surface for easier detachment, then detachment ease is improved, but image gloss and adhesion are reduced

Engineering Contradiction:
Improvedetachment easeVSAvoidimage gloss
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The invention optimizes the positional parameter of release agent domains by setting the distance from the particle surface to be 0.10 μm or more. This parameter change balances the competing requirements: close enough to provide detachment ease when needed, but far enough to prevent excessive seepage that would harm image gloss and adhesion.

Inventive Principle:
Principle #35Parameter changes

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

This solution effectively limits the reduction in image gloss when the image is rubbed by balancing adhesion and detachment properties, ensuring consistent image quality and longevity.

Implementation Method 1

a release agent with a melting temperature between 65°C and 95°C, such as an ester wax

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP4095610A1Electrostatic image developing toner, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method
Publication Date: 2022.11.30 FUJIFILM BUSINESS INNOVATION CORP
  • EP4095610A1 patent drawingFigure 1
  • EP4095610A1 patent drawingFigure 2
  • EP4095610A1 patent drawingFigure 3

AI summary

An electrostatic image developing toner includes a toner particle including a binder resin and a release agent. When a cross section of the toner particle is observed, the toner particle satisfies conditions (A) and (B) below: Condition (A): plural domains of the release agent, the domains having a diameter equal to 10% or more and 35% or less of the maximum diameter of the toner particle, are present in the toner particle; and Condition (B): the average of the distances between the centers of gravity of the domains of the release agent is 35% or more and 60% or less of the maximum diameter of the toner particle.