Fixing Member Release Layer Toner Releasability Scratch Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing fixing members for electrophotographic image forming apparatuses face challenges in achieving both high toner releasability and scratch resistance, with fluororesin release layers often compromising on one or the other due to low abrasion resistance or inferior releasability when fillers are used.

Innovation Solution

A fixing member with a release layer composed of tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, exhibiting a specific loss tangent range, is developed, which maintains high toner releasability without fillers by increasing molecular mobility through interaction with a fluorine-containing polymer compound, ensuring both excellent scratch resistance and toner releasability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a release layer including only fluororesin is used, then toner releasability is improved, but scratch resistance deteriorates

Engineering Contradiction:
Improvetoner releasabilityVSAvoidscratch resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies composite materials by combining fluororesin with specific fillers (silica, alumina, or titania) having controlled surface free energy (≤20 mN/m) and particle size (0.1-10 μm). This composite structure maintains the low surface free energy characteristic of fluororesin for toner releasability while the filler particles provide mechanical strength and scratch resistance to the release layer.

Inventive Principle:
Principle #40Composite materials

2Strength

If a filler is added to improve abrasion resistance, then scratch resistance is improved, but toner releasability deteriorates

Engineering Contradiction:
Improvescratch resistanceVSAvoidtoner releasability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the surface free energy of filler particles (≤20 mN/m) and their particle size (0.1-10 μm). These parameter optimizations ensure that the filler particles do not increase the overall surface free energy of the release layer, thereby maintaining low surface free energy for toner releasability while providing mechanical reinforcement for scratch resistance.

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 solution provides a fixing member with enhanced scratch resistance and toner releasability, contributing to the stable formation of high-quality electrophotographic images by effectively dissipating external forces and maintaining the inherent releasability of fluororesins.

Implementation Method 1

the release layer has a loss tangent at a frequency of 10 Hz and 180°C of 5.0 x 10^-2 or more and 3.0 x 10^-1 or less

Methodology Applied
Scientific EffectLoss tangent: Viscoelasticity

Data Source

PatentEP3550376B1Fixing member, fixing device, and electrophotographic image forming apparatus
Publication Date: 2020.09.23 CANON KK
  • EP3550376B1 patent drawingFigure 1A~1B
  • EP3550376B1 patent drawingFigure 2
  • EP3550376B1 patent drawingFigure 3

AI summary

Provided is a fixing member having an outer surface including excellent toner releasability and excellent scratch resistance, wherein the fixing member has a base material, an elastic layer, and a release layer in this order, the release layer including a tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, and has a loss tangent at a frequency of 10 Hz and 180°C of 5.0 x 10-2 or more and 3.0 x 10-1 or less.