Amorphous Toner Molecular Weight Distribution for Fixability and Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Toner for electrostatic charge image development in electrophotography faces a challenge where increased fixability leads to decreased resistance to thermal aggregation, particularly when stored in high temperature-high humidity environments.
Innovation Solution
A toner with toner particles containing a binder resin comprising 90 mass % or more of an amorphous resin, with specific molecular weight distribution characteristics, including a maximum peak in the range of 2,500 to 8,000, a minimum value between 8,000 and 280,000, and a maximum peak between 280,000 and 900,000, along with a controlled area ratio and peak heights, to balance fixability and thermal aggregation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the binder resin has high fixability (improved by increasing crystalline resin content or adjusting molecular weight), then the fixability is improved, but the resistance to thermal aggregation decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the molecular weight distribution of the binder resin through GPC analysis, specifying that the area ratio A/B (low molecular weight component to high molecular weight component) should be within 0.05 to 2.0. This parameter optimization allows achieving both good fixability and high resistance to thermal aggregation without using excessive crystalline resin, thereby resolving the contradiction between these two properties
Solution Approach 2:
The patent uses composite materials by combining amorphous resin with specific molecular weight distribution characteristics and crystalline resin in controlled proportions. The binder resin comprises 90 mass% or more amorphous resin with specific molecular weight peaks (Ma: 2,500-8,000; Mb: 280,000-900,000) and controlled area ratio, combined with 10 mass% or less crystalline resin, creating a composite material that achieves both fixability and thermal stability
2Stability of the object's composition
If the binder resin uses high molecular weight components to improve resistance to thermal aggregation, then thermal stability is improved, but fixability at low temperatures deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the molecular weight distribution through GPC analysis, specifying dual peaks at Ma (2,500-8,000) and Mb (280,000-900,000) with controlled area ratio A/B between 0.05 and 2.0. This precise parameter control ensures that sufficient low molecular weight components are present for low-temperature fixability while maintaining enough high molecular weight components for thermal aggregation resistance
Solution Approach 2:
The patent uses composite materials by creating a binder resin system combining amorphous resin with specific dual-peak molecular weight distribution and crystalline resin in controlled proportions (90 mass% or more amorphous resin with specific MW peaks, 10 mass% or less crystalline resin). This composite structure enables simultaneous achievement of low-temperature fixability and high-temperature thermal stability
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 both good fixability at low temperatures and high resistance to thermal aggregation, maintaining performance even with less than 20 mass % crystalline resin, ensuring stable image formation across varying conditions.
Implementation Method 1
in a differential molecular weight distribution curve of tetrahydrofuran soluble matter as measured by gel permeation chromatography, the toner has: a maximum peak Ma in a molecular weight range of 2,500 or more and 8,000 or less; a minimum value Mm in a molecular weight range of more than 8,000 and less than 280,000; and a maximum peak Mb in a molecular weight range of 280,000 or more and 900,000 or less
Implementation Method 2
in a differential molecular weight distribution curve of tetrahydrofuran soluble matter as measured by gel permeation chromatography
Implementation Method 3
tetrahydrofuran soluble matter
Data Source
AI summary
A toner for electrostatic charge image development has toner particles containing a binder resin including 90 mass % or more of an amorphous resin. In a differential molecular weight distribution curve of tetrahydrofuran soluble matter as measured by gel permeation chromatography, the toner has a maximum peak Ma in a molecular weight range of 2,500 or more and 8,000 or less, a minimum value Mm in a molecular weight range of more than 8,000 and less than 280,000, and a maximum peak Mb in a molecular weight range of 280,000 or more and 900,000 or less. When the area of the differential molecular weight distribution curve in a range of a molecular weight of 100 or more and less than the minimum value Mm is defined as A, and the area of the differential molecular weight distribution curve in a range of the minimum value Mm or more and a molecular weight of 10,000,000 or less is defined as B, the area ratio A/B is 5.5 or more and 10 or less.