Urethane Undercoat with Titanium Oxide for Stable Potential
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrophotographic photosensitive members experience variations in potential and sensitivity during repeated use, leading to image defects such as black spots, due to the limitations in the choice of metal oxides and binder resins in the undercoat layer.
Innovation Solution
Incorporating titanium oxide secondary particles with a specific particle diameter range and a high-resistant urethane resin in the undercoat layer to enhance conductivity and reduce charge variation, while maintaining appropriate resistance to prevent image defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional metal oxide particles and binder resins are used in the undercoat layer, then the photosensitive member can be manufactured with standard materials, but the potential characteristics show significant variation during repeated use
Solution Approach 1:
The patent changes the particle size parameters of titanium oxide particles (primary particles: 1-10 nm, secondary particles: 200-500 nm) and specifies the binder resin type (urethane resin with specific glass transition temperature) to achieve stable potential characteristics during repeated use
Solution Approach 2:
The patent uses a composite undercoat layer containing titanium oxide particles combined with urethane resin binder, creating a composite material system that provides both conductivity and mechanical stability, reducing potential variation during repeated use
2Reliability
If the undercoat layer conductivity is increased to improve charging ability, then sensitivity improves, but image defects such as black spots occur
Solution Approach 1:
The patent optimizes the particle size parameters of titanium oxide (primary: 1-10 nm, secondary: 200-500 nm) to achieve appropriate conductivity that provides good charging ability while preventing image defects like black spots
Solution Approach 2:
The patent creates local quality differences in the undercoat layer by using a core-shell structure of titanium oxide particles with different sizes, where the core provides conductivity and the shell structure prevents excessive charge accumulation that would cause black spots
3Strength
If larger metal oxide particles are used to improve undercoat layer durability, then mechanical strength increases, but potential characteristics and sensitivity deteriorate
Solution Approach 1:
The patent segments the titanium oxide particles into primary particles (1-10 nm) and secondary particles (200-500 nm), where primary particles provide surface area for charge generation and secondary particles provide structural durability, achieving both strength and potential characteristics
Solution Approach 2:
The patent uses a nested structure where primary titanium oxide particles are aggregated to form secondary particles, creating a hierarchical structure that provides both the surface area needed for good potential characteristics and the structural integrity for durability
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 reduces potential variation and maintains charging ability, thereby minimizing image defects like black spots during long-term use.
Implementation Method 1
an undercoat layer containing metal oxide particles and an organic compound... titanium oxide particles... the potential characteristics (charging ability and sensitivity) of the electrophotographic photosensitive member
Data Source
AI summary
There is provided an electrophotographic photosensitive member in which the variation in potential during repeated use is reduced. The electrophotographic photosensitive member is the electrophotographic photosensitive member of which an undercoat layer comprises a urethane resin and titanium oxide particles whose primary particle and secondary particle diameters are defined.