Charge Transport Layer Wear Reduction in Electrophotographic Imaging

Solution Overview

Problem

Conventional photoreceptors used in bias charge roll (BCR) charging systems experience significant wear and damage, leading to a short service life of only several thousand prints, necessitating continuous improvement to enhance wear resistance and extend photoreceptor life.

Innovation Solution

An electrophotographic imaging member with a charge transport layer comprising a tetraaryl polycarbonate binder and perfluorinated fluoropolymer fillers, such as polytetrafluoroethylene, is developed, which reduces wear rates and extends service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional photoreceptors are used in BCR charging systems, then the charging function is achieved, but the wear rate is high and service life is short

Engineering Contradiction:

Improveservice lifeVSAvoidwear resistance

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The charge transport layer uses a composite material system comprising a polycarbonate binder matrix combined with fluoropolymer particles (PTFE, PFA, or FEP). This composite structure leverages the mechanical strength of polycarbonate and the wear resistance of fluoropolymers to create a layer that simultaneously provides charge transport functionality and enhanced durability against BCR charging wear, directly resolving the contradiction between service life and wear resistance

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention modifies the chemical composition parameters of the charge transport layer by incorporating fluoropolymer particles at specific weight ratios (5-50 wt%). This parameter change transforms the material properties to reduce wear rates by up to 50% compared to conventional polycarbonate-only formulations, thereby extending service life while maintaining charging functionality

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the charge transport layer uses conventional polycarbonate binder, then the layer provides basic charge transport, but the wear rate is high under BCR charging

Engineering Contradiction:

Improvewear resistanceVSAvoidservice life

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The charge transport layer uses a composite material system comprising a polycarbonate binder matrix combined with fluoropolymer particles (PTFE, PFA, or FEP). This composite structure leverages the mechanical strength of polycarbonate and the wear resistance of fluoropolymers to create a layer that simultaneously provides charge transport functionality and enhanced durability against BCR charging wear, directly resolving the contradiction between service life and wear resistance

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention modifies the chemical composition parameters of the charge transport layer by incorporating fluoropolymer particles at specific weight ratios (5-50 wt%). This parameter change transforms the material properties to reduce wear rates by up to 50% compared to conventional polycarbonate-only formulations, thereby extending service life while maintaining charging functionality

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8765339B2Imaging member layers

Publication Date: 2014.07.01 XEROX CORP

AI summary

The presently disclosed embodiments relate generally to layers that are useful in imaging apparatus members and components, for use in electrophotographic, including digital printing, apparatuses. More particularly, the embodiments pertain to an improved electrophotographic imaging member comprising a charge transport layer comprising a novel combination of a tetraaryl polycarbonate copolymer binder and perfluorinated fillers. The present charge transport layer provides reduced wear rate and long service life.