Toner Resin Adsorption for Low-Temp Fixability and Durability

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Solution Overview

Problem

Current toners face challenges in achieving high-speed electrophotographic processes with both low-temperature fixability and durability, as well as maintaining high tinting strength, with existing solutions either compromising on durability or tinting strength.

Innovation Solution

A toner formulation comprising toner particles with a binder resin, pigment, crystalline resin, and amorphous resin, where the adsorption rates and compatibility between these components are carefully controlled to optimize low-temperature fixability and tinting strength, including the use of a polyester resin with an adamantane structure for improved dispersibility and triboelectric stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a crystalline resin is used to improve low-temperature fixability, then the low-temperature fixability is improved, but the durability is insufficient in high-speed electrophotographic processes

Engineering Contradiction:
Improvelow-temperature fixabilityVSAvoiddurability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent uses a composite material system consisting of both crystalline resin and amorphous resin. The crystalline resin (e.g., polyester resin with specific melting point) provides low-temperature fixability by melting and bonding at lower temperatures, while the amorphous resin (e.g., polyamide resin or polyester resin without crystalline structure) provides durability and mechanical strength. This composite approach allows both requirements to be satisfied simultaneously.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes specific parameters including the melting point of the crystalline resin (50-110°C), the glass transition temperature of the amorphous resin (60-120°C), and their weight ratios (crystalline resin 1-30 parts, amorphous resin 1-20 parts relative to binder resin). By carefully controlling these parameters, the toner achieves both low-temperature fixability and high-speed durability.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the process speed is increased to 200 mm/s or more for high-speed printing, then the productivity is improved, but the durability of the toner is reduced

Engineering Contradiction:
Improveprocess speedVSAvoiddurability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The amorphous resin component in the composite material system provides enhanced mechanical strength and durability that enables the toner to withstand the mechanical stresses of high-speed electrophotographic processes (200 mm/s or more). The amorphous structure prevents crystallization during rapid processing while maintaining particle integrity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The glass transition temperature of the amorphous resin is controlled within 60-120°C to optimize durability at high speeds. This parameter adjustment ensures the toner maintains appropriate flexibility and strength during high-speed processing without becoming too rigid or too soft.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If a crystalline resin with high adsorption rate to pigment is used to improve tinting strength, then the tinting strength is improved, but the low-temperature fixability may be compromised

Engineering Contradiction:
Improvetinting strengthVSAvoidlow-temperature fixability
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent optimizes the adsorption rate of crystalline resin to pigment within 5-40% and the adsorption rate of amorphous resin to pigment within 20-60%. This balanced control ensures sufficient pigment dispersion for high tinting strength while maintaining adequate resin-pigment interaction for effective low-temperature fixation. The specific surface area of the pigment is also controlled (5-50 m²/g) to achieve optimal adsorption characteristics.

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

The toner exhibits enhanced low-temperature fixability, durability, and high tinting strength even at high speeds, while maintaining image quality and stability across various environments.

Implementation Method 1

the adsorption rate A1 of the crystalline resin to the pigment is in the range of from 5% to 40%

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

the adsorption rate A2 of the amorphous resin to the pigment is in the range of from 20% to 60%

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

an exothermic quantity per gram (J/° C.) of the crystalline resin at an exothermic peak derived from the crystallization of the crystalline resin

Methodology Applied
Scientific EffectCrystallization: Crystallisation

Data Source

PatentUS9964872B2Toner and method for producing the same
Publication Date: 2018.05.08 CANON KK

AI summary

A toner including toner particles containing a binder resin, a pigment, a crystalline resin and an amorphous resin. The adsorption rate A1 of the crystalline resin to the pigment is from 5% to 40%, and the adsorption rate A2 of the amorphous resin to the pigment is from 20% to 60%. The adsorption rates A1 and A2 satisfy relationship (1): A1<A2. The degree of compatibility expressed by equation (2) is 70% or less:Degree of compatibility (%)=(1−B1/B2)×100  (2)