Triphenylamine Polyarylate Photosensitive Layer Transfer Memory

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Solution Overview

Problem

The existing electrophotographic photosensitive members fail to sufficiently inhibit the occurrence of transfer memory, leading to image defects in image forming apparatuses.

Innovation Solution

An electrophotographic photosensitive member is developed with a conductive substrate and a single-layer photosensitive layer containing a charge generating material, a hole transport material, an electron transport material, and a binder resin, where the hole transport material is a triphenylamine derivative and the electron transport material includes specific compounds, and the binder resin is a polyarylate resin, which effectively inhibits transfer memory.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional electrophotographic photosensitive members are used, then basic image formation is achieved, but transfer memory cannot be sufficiently inhibited

Engineering Contradiction:

Improveinhibition of transfer memoryVSAvoidphotosensitive layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining specific hole transport materials (triphenylamine derivatives) and electron transport materials in defined weight ratios within the photosensitive layer. This composite approach resolves the contradiction by achieving superior transfer memory inhibition through material composition rather than structural complexity

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent employs parameter changes by optimizing the weight ratios of hole transport material (20-80 parts) and electron transport material (20-80 parts) relative to the binder resin (100 parts). By adjusting these compositional parameters, the invention achieves effective transfer memory inhibition while maintaining a relatively simple single-layer structure

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If existing photosensitive members are used, then image formation is possible, but image defects occur due to transfer memory

Engineering Contradiction:

Improveimage qualityVSAvoidtransfer memory and image defects

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potentially harmful interaction between hole and electron transport materials into a beneficial effect. By carefully selecting and combining specific materials (triphenylamine derivatives with electron transport materials) in optimal ratios, the patent transforms what could be harmful material interactions into a mechanism that actively inhibits transfer memory and prevents image defects

Inventive Principle:

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

Solution Approach 2:

The composite material approach combines hole transport and electron transport materials with complementary properties. This composite structure resolves the contradiction by leveraging the synergistic effects of different materials to achieve high image quality while suppressing transfer memory-induced defects

Inventive Principle:

Principle #40Composite materials

3Device complexity

If a single-layer photosensitive layer is used, then device complexity is reduced, but sufficient inhibition of transfer memory is difficult to achieve

Engineering Contradiction:

Improvephotosensitive layer structureVSAvoidinhibition of transfer memory

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent achieves effective transfer memory inhibition in a single-layer structure by changing the compositional parameters. Specifically, it optimizes the weight ratios of hole transport material (20-80 parts) and electron transport material (20-80 parts) relative to the binder resin (100 parts), allowing a simple single-layer structure to achieve performance comparable to or better than multi-layer configurations

Inventive Principle:

Principle #35Parameter changes

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 inhibits the occurrence of transfer memory and image defects, ensuring uniform charging and improved sensitivity characteristics in image forming processes.

Implementation Method 1

a photosensitive layer containing a charge generating material, a hole transport material, an electron transport material, and a binder resin

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

The hole transport material includes a triphenylamine derivative

Methodology Applied

Scientific EffectCharge Transport: Conduction (electrical)

Implementation Method 3

The electron transport material includes a compound represented by general formula (ET1), general formula (ET2), general formula (ET3), general formula (ET4), or general formula (ET5)

Methodology Applied

Scientific EffectCharge Transport: Conduction (electrical)

Data Source

PatentUS10761440B2Electrophotographic photosensitive member, process cartridge, and image forming apparatus

Publication Date: 2020.09.01 KYOCERA DOCUMENT SOLUTIONS INC

AI summary

A photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3). The photosensitive layer is a single-layer photosensitive layer (3c). The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The hole transport material includes a triphenylamine derivative represented by general formula (HT). The electron transport material includes a compound represented by general formula (ET1), (ET2), (ET3), (ET4), or (ET5). The binder resin includes a polyarylate resin represented by general formula (1)