Electrophotographic Photosensitive Member Conductive Layer Design
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Solution Overview
Problem
Electrophotographic photosensitive members face issues with image defects such as charging non-uniformity and discharge breakdown due to direct voltage application in contact charging systems, particularly in DC contact charging systems, which result in striped image defects and reduced image quality.
Innovation Solution
An electrophotographic photosensitive member is developed with a conductive layer containing conductive particles and a polyolefin resin with specific repeating structural units, applied in a specific mass ratio, which suppresses image defects by providing conductivity and electrical blocking functions, and is integrated with an intermediate layer and photosensitive layer on a conductive support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick layer containing conductive material is provided on the support to achieve conductivity and electrical blocking function, then the electrical blocking function is improved, but the layer becomes complex and difficult to manufacture with uniform thickness
Solution Approach 1:
The patent divides the layer between the photosensitive layer and support into two distinct functional layers: a conductive layer containing conductive particles (providing conductivity and hiding function) and an intermediate layer free of conductive material (providing electrical blocking function). This segmentation allows each layer to be optimized for its specific function without the complexity of creating a thick laminate structure, while achieving both electrical blocking and conductivity requirements.
2Reliability
If polyolefin resin is used in the conductive layer to improve dielectric characteristics, then the electrical properties are improved, but the resin shows poor solubility making it difficult to prepare stable application liquid
Solution Approach 1:
The patent modifies the polyolefin resin by introducing specific repeating structural units (A1), (A2), and (A3) with controlled mass ratios. Unit (A2) containing carboxyl or carboxylic acid anhydride groups provides polarity for solubility, while units (A1) and (A3) maintain the polyolefin backbone for dielectric properties. This parameter change in molecular structure allows the resin to achieve both good solubility for stable application liquid preparation and excellent dielectric characteristics in the conductive layer.
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 image defects from charging non-uniformity, maintaining an excellent film state and improving image quality even in DC contact charging systems, ensuring consistent and high-quality image production.
Implementation Method 1
a conductive layer containing conductive particles having a volume-average particle diameter of 0.1 μm or more
Implementation Method 2
the conductive layer contains a polyolefin resin having the following repeating structural units (A1), (A2), and (A3)... the layer has the electrical blocking function
Implementation Method 3
the conductive layer suppresses image defects resulting from charging non-uniformity, and is in an excellent film state... suppresses image defects from charging non-uniformity
Data Source
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AI summary
The present invention relates to an electrophotographic photosensitive member obtained by providing, on a conductive support, a conductive layer containing conductive particles having a volume-average particle diameter of 0.1 µm or more, an intermediate layer, and a photosensitive layer in the stated order in which the conductive layer contains a polyolefin resin containing a specific repeating structural unit at a specific ratio, and a process cartridge and an electrophotographic apparatus each having the electrophotographic photosensitive member.