Undercoat Polymer Structure for Electrophotographic Ghost Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrophotographic photosensitive members suffer from significant positive ghosting issues, which affect image quality, and existing techniques for suppressing this phenomenon are inadequate.
Innovation Solution
Incorporating a specific polymer with a particular structural unit in the undercoat layer of the electrophotographic photosensitive member, characterized by alternating electron transportable and non-electron transportable sites with carboxyl or sulfo groups, to enhance the suppression of positive ghosting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an undercoat layer is provided between the photosensitive layer and support, then exfoliation and image defects are suppressed, but positive ghosting occurs
Solution Approach 1:
The patent changes the chemical and structural parameters of the undercoat layer by incorporating a specific polymer with repeating units containing electron transportable groups (such as triphenylamine derivatives) and non-electron transportable groups (such as carboxyl or sulfo groups). This parameter change modifies the electron transport characteristics of the undercoat layer to suppress positive ghosting while maintaining its protective function.
Solution Approach 2:
The undercoat layer uses a composite polymer structure combining electron transportable moieties and non-electron transportable moieties in alternating sequences. This composite material approach allows the undercoat layer to simultaneously provide mechanical support (preventing exfoliation) and control electron transport (suppressing positive ghosting) through the synergistic combination of different functional groups.
2Reliability
If conventional electron transport materials are used in the undercoat layer, then electron transport function is improved, but positive ghosting suppression is insufficient
Solution Approach 1:
The patent segments the undercoat layer's functional groups into alternating electron transportable sites and non-electron transportable sites along the polymer chain. This segmentation creates a controlled electron transport pathway that prevents excessive electron migration while maintaining sufficient electron transport function, thereby suppressing positive ghosting more effectively than conventional electron transport materials.
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 polymer structure effectively reduces positive ghosting by ensuring even distribution of electron transportable sites, leading to improved image quality and reduced density differences in halftone images.
Implementation Method 1
making a polymer having a specific structure contained in the undercoat layer of an electrophotographic photosensitive member... the undercoat layer includes a polymer having a repeating structural unit... alternating electron transportable and non-electron transportable sites
Data Source
AI summary
An undercoat layer of an electrophotographic photosensitive member contains a polymer having a specific repeating structural unit in order to provide an electrophotographic photosensitive member that suppresses positive ghost, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.