Toner Hydrocarbon Wax Melting Half-Width Ratio

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Solution Overview

Problem

Existing toner technologies face challenges in achieving a balance between low-temperature fixability and heat-resistant storability while maintaining excellent fixed image reliability, as waxes with narrow or broad melting temperature ranges compromise either low-temperature fixability or heat-resistant storability.

Innovation Solution

A toner composition with a specific ratio of hydrocarbon wax half-widths before and after the fixing step, achieved through controlled heat treatment processes, ensures optimal wax melting properties for both low-temperature fixability and heat-resistant storability, and includes a binder resin and colorant.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a low-melting wax is used to enhance low-temperature fixability, then the low-temperature fixability is improved, but the heat-resistant storability is lost

Engineering Contradiction:
Improvelow-temperature fixabilityVSAvoidheat-resistant storability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The invention changes the critical parameter of wax melting temperature to a specific range (50°C to 90°C) with controlled half-width (2.0°C to 12.0°C). This parameter optimization allows the wax to remain stable during storage at higher temperatures while melting at the fixing temperature, thus achieving both heat-resistant storability and low-temperature fixability simultaneously.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention utilizes the phase transition properties of wax with a controlled melting temperature range. The wax undergoes phase transition from solid to liquid at the fixing temperature (50°C to 90°C), providing low-temperature fixability, while remaining solid during storage at higher temperatures, ensuring heat-resistant storability. The controlled half-width of the melting peak ensures sharp phase transition for optimal performance.

Inventive Principle:
Principle #36Phase transitions

2Temperature

If a wax with a narrow melting temperature range is used to achieve rapid melting at fixing temperature, then low-temperature fixability is enhanced, but the rubbing resistance of the fixed image deteriorates

Engineering Contradiction:
Improvelow-temperature fixabilityVSAvoidrubbing resistance of fixed image
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The invention optimizes the half-width of the wax melting peak to a specific range (2.0°C to 12.0°C). This controlled parameter ensures the wax melts rapidly enough at the fixing temperature to provide good low-temperature fixability, while maintaining sufficient melting temperature range to prevent excessive wax bleeding that would compromise image rubbing resistance.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a wax with a broad melting temperature range is used to improve fixed image strength, then the rubbing resistance is improved, but the low-temperature fixability and heat-resistant storability balance is compromised

Engineering Contradiction:
Improvefixed image strengthVSAvoidlow-temperature fixability and heat-resistant storability balance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention changes the half-width parameter of the wax melting peak to an optimized range (2.0°C to 12.0°C), which is neither too narrow nor too broad. This controlled parameter provides sufficient melting temperature range to maintain fixed image strength and rubbing resistance, while keeping the melting range sharp enough to achieve good low-temperature fixability and heat-resistant storability balance.

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 achieves a good balance of low-temperature fixability and heat-resistant storability with excellent fixed image reliability, preventing wax bleeding and maintaining thermal properties over time, even in high-temperature, high-humidity environments.

Implementation Method 1

the wax can be made to rapidly melt at a desired temperature

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

enhance the releasability of the toner from the fixing member by including wax in the toner, and also increase the low-temperature fixability by plasticizing the binder resin with wax that has melted during fixing

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

the half width of the endothermic peak, as determined with a differential scanning calorimeter

Methodology Applied
Scientific EffectCalorimetry: Calorimetry

Implementation Method 4

a method of producing such a toner which comprises: heat-treating the toner

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentUS9366981B2Toner and toner production method
Publication Date: 2016.06.14 CANON KK

AI summary

A toner which includes a binder resin, a colorant and a hydrocarbon wax has a ratio W1/W2 of the half width W1 (° C.) of a endothermic peak derived from melting of the hydrocarbon wax in a first temperature rise process on the toner to the half width W2 (° C.) of a endothermic peak derived from melting of the hydrocarbon wax in a second temperature rise process, as measured with a differential scanning calorimeter, with the ratio W1/W2 being not less than 0.50 and not more than 0.90.