Fluororesin-Siloxane Fixing Member Surface for Wax Offset Control
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Solution Overview
Problem
Existing fixing members in electrophotographic image forming apparatuses experience gloss unevenness, known as wax offset, when using fluororesin surfaces due to insufficient toner releasability, particularly on high-quality media like transparent films and high-gloss papers.
Innovation Solution
A fixing member with a surface layer having a sliding angle of 25 degrees or less at 150°C with respect to Fischer-Tropsch wax having a melting point of 90°C and a penetration of 3 (1/10 mm) is employed, enhancing toner releasability and reducing wax offset.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fluororesin surface is used for fixing member, then heat resistance and chemical stability are improved, but gloss unevenness (wax offset) occurs due to insufficient toner releasability
Solution Approach 1:
The surface layer is formed as a composite material comprising a fluororesin base resin and a siloxane compound. This composite structure combines the heat resistance and chemical stability of fluororesin with the low surface energy and excellent releasability of siloxane, thereby suppressing gloss unevenness while maintaining the beneficial properties of fluororesin.
Solution Approach 2:
The invention changes the chemical composition parameters of the surface layer by incorporating a siloxane compound with specific structural characteristics ( Formula (1) where R represents a specific organic group). This parameter change modifies the surface energy characteristics to achieve a sliding angle of 25° or less, improving toner releasability without sacrificing the thermal and chemical stability provided by the fluororesin matrix.
2Reliability
If mold release agent is applied to improve toner releasability, then fixing performance is improved, but gloss unevenness occurs on high-quality media surfaces
Solution Approach 1:
The siloxane compound acts as an intermediary substance within the surface layer that provides the necessary releasability function. Instead of applying a separate mold release agent that can transfer to media, the siloxane is integrated into the surface layer structure itself, mediating between the toner and the fluororesin substrate to enable smooth release without causing gloss unevenness on high-quality media.
Solution Approach 2:
The invention replaces the mechanical application of mold release agents with an intrinsic surface property approach. The siloxane-containing surface layer inherently provides low friction and excellent releasability through its molecular structure, eliminating the need for separate release agents that could transfer to media and cause gloss unevenness.
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 effectively suppresses gloss unevenness, ensuring high-quality image printing on smooth surfaces by minimizing the presence of mold release agents on the fixing member surface.
Implementation Method 1
a surface layer having a sliding angle of 25 degrees or less at 150° C. with respect to a Fischer-Tropsch wax
Data Source
AI summary
A fixing member includes a surface layer having a sliding angle of 25 degrees or less at 150° C. with respect to a Fischer-Tropsch wax having a melting point of 90° C. and a penetration of 3 ( 1/10 mm).