Corona Resistant Imaging Member with Ozone Quenching
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Solution Overview
Problem
Electrophotographic imaging members in electrostatographic systems face premature mechanical failures due to frictional abrasion, wear, and surface cracking, particularly in flexible belt designs, caused by dynamic fatigue and exposure to airborne contaminants like solvent vapors and corona species, which shorten their service life and increase replacement costs.
Innovation Solution
A corona-resistant charge transport layer is formulated using a polycarbonate binder with N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1-biphenyl-4,4′-diamine and an ozone quenching compound, along with a mechanically robust overcoat layer to enhance wear resistance and extend the service life of the imaging members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a typical charge transport layer is used in flexible belt imaging members, then the imaging member can be manufactured with standard materials and processes, but the imaging member exhibits premature mechanical failures due to frictional abrasion, wear, and surface cracking
Solution Approach 1:
The patent applies composite materials by combining polycarbonate binder with specific charge transport compounds (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1-biphenyl-4,4'-diamine) and ozone quenching compounds to create a charge transport layer with enhanced wear resistance and corona resistance. This composite formulation resolves the contradiction by providing both standard manufacturability and improved mechanical strength/wear resistance.
Solution Approach 2:
The patent introduces an ozone quenching compound as an intermediary substance within the charge transport layer that mediates between the harmful ozone/corona species and the polycarbonate binder. This intermediary protects the binder from ozone-induced degradation, thereby extending service life and improving wear resistance without compromising the basic charge transport function.
2Productivity
If the imaging member is exposed to corona species and airborne contaminants during normal operation, then the imaging member performs its electrophotographic function, but the imaging member suffers from surface cracking and wear
Solution Approach 1:
The patent converts the harmful ozone/corona species into a beneficial protective mechanism by incorporating ozone quenching compounds that react with ozone to form stable products. This transforms the harmful corona environment into a controlled chemical reaction that protects the charge transport layer, allowing continuous imaging operation without surface cracking.
Solution Approach 2:
The patent changes the chemical parameters of the charge transport layer by incorporating specific ozone quenching compounds with defined molecular structures and reactivity characteristics. This parameter change enables the layer to resist ozone attack while maintaining its electrophotographic function, thus protecting against corona damage during normal imaging operations.
3Shape
If an anticurl back coating is applied to balance curl in flexible belts, then the imaging member achieves desirable flatness, but the imaging member still suffers from upward curling after coating
Solution Approach 1:
The patent changes the material parameters of the charge transport layer by using polycarbonate binder with specific charge transport compounds and ozone quenching compounds. This parameter change affects the thermal and mechanical properties of the coating, improving adhesion and reducing curling tendencies while maintaining flatness, thus resolving the contradiction between achieving flatness and maintaining curl balance.
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 significantly improves wear resistance and cracking life extension, providing enhanced durability and extending the mechanical service life of electrophotographic imaging members by protecting against ozone-induced degradation and corona attacks, thus reducing the frequency of replacements and maintenance costs.
Implementation Method 1
the charge transport layer comprises a polycarbonate binder, a charge transport compound of N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1-biphenyl-4,4′-diamine, and an ozone quenching compound
Implementation Method 2
a charge generating layer disposed on the substrate, and at least one charge transport layer disposed on the charge generating layer
Data Source
AI summary
The presently disclosed embodiments relate in general to electrophotographic imaging members, such as layered photoreceptor structures, and processes for making and using the same. More particularly, the embodiments pertain to the incorporation of an ozone quenching compound into the charge transport layer to quench the corona effluents and protect the polycarbonate binder of the charge transport layer from being attacked by ozone species, thereby enhancing wear resistance and fatigue cracking.