Electrophotographic Photosensitive Member Undercoat Layer Moisture Resistance

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Solution Overview

Problem

Electrophotographic photosensitive members experience significant changes in potential characteristics, particularly under high-temperature and high-humidity environments, leading to degradation in charging properties and sensitivity, especially during long-term repetitive use and short-term use after prolonged periods of inactivity.

Innovation Solution

Incorporating a compound represented by a specific formula into the undercoat layer of the electrophotographic photosensitive member, which contains metal oxide particles, to form an intramolecular charge transfer complex, thereby reducing moisture absorption and stabilizing electrical charge retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal oxide particles are used in the undercoat layer to improve potential characteristics, then charging property and sensitivity are improved, but the change in potential increases during repetitive use under high-temperature and high-humidity environments

Engineering Contradiction:

Improvepotential characteristics stabilityVSAvoidmoisture absorption

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An organic compound is introduced as an intermediary substance between the metal oxide particles and the external environment. This compound forms a protective interface that prevents moisture from reaching the metal oxide particles, thereby maintaining their electrical charge flow properties while still allowing them to function in improving potential characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The undercoat layer is designed as a composite material system combining metal oxide particles with an organic compound. This composite structure leverages the electrical charge flow enhancement properties of metal oxide particles while the organic compound provides moisture resistance, achieving both improved potential characteristics and stability under humid conditions.

Inventive Principle:

Principle #40Composite materials

2Productivity

If the electrophotographic photosensitive member is used for long-term repetitive use, then productivity is improved, but the change in potential increases causing remarkable degradation in potential characteristics

Engineering Contradiction:

Improvecontinuous operation capabilityVSAvoidpotential characteristics stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The organic compound is incorporated into the undercoat layer structure in advance to create a protective barrier against moisture. This pre-established protection cushioning prevents moisture from affecting the metal oxide particles during long-term operation, thereby maintaining potential characteristics stability throughout extended use periods.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The chemical composition parameters of the undercoat layer are modified by adding the organic compound with specific moisture-resistant properties. This parameter change transforms the undercoat layer from a moisture-vulnerable structure to a moisture-resistant one, enabling stable performance during prolonged repetitive use.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the electrophotographic photosensitive member is left to stand after long-term repetitive use, then recovery of potential characteristics is expected, but recovery performance is inferior

Engineering Contradiction:

Improverecovery performanceVSAvoidrecovery time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The organic compound, which primarily serves to prevent moisture absorption during operation, also provides a secondary benefit by facilitating faster recovery of potential characteristics after standing periods. The same moisture-resistant properties that protect during operation also prevent moisture-related degradation that would slow recovery, thereby converting the protective function into a recovery-enhancing function.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 changes in potential characteristics, maintaining stable image output even after long-term repetitive use under high-temperature and high-humidity conditions, and quickly recovers potential characteristics after short-term use, ensuring consistent image quality.

Implementation Method 1

Methodology Applied

Scientific EffectIntramolecular charge transfer complex formation:

Data Source

PatentUS9557664B2Electrophotographic photosensitive member, method for manufacturing the same, process cartridge, and electrophotographic apparatus

Publication Date: 2017.01.31 CANON KK

AI summary

The present invention provides an electrophotographic photosensitive member which includes an undercoat layer, and the undercoat layer contains metal oxide particles and a compound represented by the formula (1).