Amorphous Polyester Toner with Silica Additives for Stable Charge

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Toner particles with reduced sizes face challenges in maintaining stable chargeability and dischargeability, leading to deteriorated image quality during continuous printing at high image densities, especially in low-temperature fixability applications.

Innovation Solution

Incorporating an amorphous polyester resin as the main binding resin and small-sized spherical silica particles as external additives, which enhance toner fluidity and charge rise properties, ensuring stable chargeability and high-quality image formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the particle size of toner is reduced to enable low-temperature fixation and fine latent image reproduction, then low-temperature fixability and image quality are improved, but toner bottle dischargeability deteriorates

Engineering Contradiction:
Improvefixation temperatureVSAvoidtoner bottle dischargeability
Core Design Contradiction:
TemperatureVSEase of operation

Solution Approach 1:

The patent changes the particle size parameter of spherical silica particles to a specific range (20-55 nm) to optimize both toner fluidity for bottle dischargeability and charge rise properties. This parameter optimization resolves the contradiction by finding the optimal size that maintains dischargeability while enabling low-temperature fixation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite structure combining amorphous polyester resin as the main binding resin with small-sized spherical silica particles as external additives. This composite material approach allows the toner to achieve both low-temperature fixability and favorable dischargeability by synergistically combining the properties of different materials.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If the particle size of toner is reduced to enable fine latent image reproduction, then image quality is improved, but chargeability deteriorates

Engineering Contradiction:
Improvefine latent image reproductionVSAvoidchargeability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent optimizes the particle size parameter of spherical silica particles to 20-55 nm, which enhances charge rise properties while maintaining fine latent image reproduction capability. This parameter control resolves the contradiction between particle size reduction and chargeability maintenance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The spherical silica particles act as an intermediary substance that facilitates charge accumulation on the toner surface. These particles mediate between the reduced toner particle size and the need for sufficient chargeability, enabling fine image reproduction while maintaining reliable charge properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If the particle size of toner is reduced to enable energy saving, then energy consumption is reduced, but dischargeability and chargeability deteriorate

Engineering Contradiction:
Improvefixation energyVSAvoiddischargeability and chargeability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent employs a composite material system with amorphous polyester resin and small-sized spherical silica particles that enables energy saving through reduced particle size while maintaining reliable dischargeability and chargeability. The composite structure compensates for the negative effects of size reduction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the particle size parameter of spherical silica additives to 20-55 nm, which allows the toner to achieve reduced particle size for energy saving while maintaining favorable dischargeability and chargeability through the synergistic effect of the composite material system.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If continuous printing at high image density is performed, then productivity is improved, but charge stability deteriorates

Engineering Contradiction:
Improvecontinuous printing outputVSAvoidcharge stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The spherical silica particles serve as an intermediary that stabilizes charge properties during continuous printing operations. These particles help maintain consistent charge levels on toner particles even under high-stress conditions of continuous high-density printing, thereby preserving charge stability while enabling high productivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enables favorable toner bottle dischargeability and stable chargeability, allowing for high-quality image formation at high image densities while maintaining low-temperature fixability, thus addressing the issues of reduced particle size and charge stability.

Implementation Method 1

a spherical silica particle (1) having a number average particle size in the range from 20 to 55 nm is included as the external additive... can be enchanted in toner fluidity and thus have favorable toner bottle dischargeability

Methodology Applied
Scientific EffectFluidity enhancement: Friction

Implementation Method 2

can be enhanced in the rise of the amount of charge of a toner particle and thus keep stable chargeability

Methodology Applied
Scientific EffectCharge rise: Triboelectric Effect

Data Source

PatentUS10564558B2Electrostatic charge image developing toner and two-component developer
Publication Date: 2020.02.18 KONICA MINOLTA INC

AI summary

The electrostatic charge image developing toner of the present invention is an electrostatic charge image developing toner including a toner mother particle including at least a binding resin, and an external additive attached onto a surface of the toner mother particle, wherein a median size on a volume basis of the toner mother particle is in the range from 3.0 to 5.0 μm, the binding resin contains at least an amorphous polyester resin as a main component, and a spherical silica particle (1) having a number average particle size in the range from 20 to 55 nm is included as the external additive.