Photocurable Photoreceptor Coating for Stable Surface Potential

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Solution Overview

Problem

Existing electrophotographic photoreceptors with a photocurable resin in the protective layer face issues with potential stability due to curing failures and decreased performance.

Innovation Solution

The photoreceptor includes a photosensitive layer with a hole transporting agent having two or less chain ethene-1,2-diyl groups or no such groups, and a protective layer with a photocurable resin, where the ratio of specific absorbances measured by Fourier transform infrared spectroscopy is 0.160 or less, ensuring complete curing and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a protective layer including a photocurable resin is provided on the photosensitive layer, then the wear resistance and lifetime of the photoreceptor are improved, but the potential stability decreases and curing failure occurs

Engineering Contradiction:
Improvewear resistanceVSAvoidpotential stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the chemical structure parameters of the hole transporting agent by limiting it to have two or less chain ethene-1,2-diyl groups. This parameter modification allows the hole transporting agent to be sufficiently stable during UV irradiation for photocuring the protective layer, while still maintaining good hole transport capability. This resolves the contradiction by adjusting molecular structure parameters to achieve both wear resistance (through photocurable protective layer) and potential stability.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If a photocurable resin is used in the protective layer, then the protective layer can be sufficiently cured to provide hard protection, but decomposition of the hole transporting agent occurs

Engineering Contradiction:
Improvecuring completenessVSAvoiddecomposition of hole transporting agent
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The invention modifies the chemical structure parameter of the hole transporting agent by restricting it to have two or less chain ethene-1,2-diyl groups. This structural parameter change makes the hole transporting agent resistant to UV-induced decomposition while allowing complete photocuring of the protective layer. The modified structure prevents harmful decomposition reactions during the photocuring process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention converts the potential harmful effect of UV irradiation (which could decompose the hole transporting agent) into a beneficial process. By selecting a hole transporting agent with specific structural stability, the UV rays needed for photocuring the protective layer no longer cause decomposition but instead successfully complete the curing process without harmful side effects.

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 allows for sufficient curing of the protective layer with a photocurable resin, enhancing the photoreceptor's potential stability and preventing decomposition of the hole transporting agent, thereby improving the photoreceptor's performance.

Implementation Method 1

the photocurable resin is formed by applying ultraviolet rays to at least one of a monomer or an oligomer on the photosensitive layer to polymerize the at least one of the monomer or the oligomer

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 2

A ratio A/B of first absorbance A of the protective layer to second absorbance B of the protective layer is 0.160 or less, the first absorbance and the second absorbance being measured by Fourier transform infrared spectroscopy

Methodology Applied
Scientific EffectInfrared absorption: Absorption (EM radiation)

Data Source

PatentEP4685564A1Electrophotographic photoreceptor, method for manufacturing electrophotographic photoreceptor, process cartridge, and image formation device
Publication Date: 2026.01.28 KYOCERA DOCUMENT SOLUTIONS INC
  • EP4685564A1 patent drawingFigure 1~2
  • EP4685564A1 patent drawingFigure 3~5
  • EP4685564A1 patent drawingFigure 6~7

AI summary

An electrophotographic photoreceptor includes a conductive substrate (2), a photosensitive layer (3), and a protective layer (5). The photosensitive layer (3) includes a charge generating agent, a hole transporting agent, and a binder resin. The hole transporting agent has two or less chain ethene-1,2-diyl groups or no chain ethene-1,2-diyl group. The protective layer (5) is a top surface layer of the electrophotographic photoreceptor and includes a photocurable resin. A ratio A/B of first absorbance A of the protective layer (5) to second absorbance B of the protective layer (5) is 0.160 or less, the first absorbance and the second absorbance being measured by Fourier transform infrared spectroscopy. The first absorbance is the highest absorbance in a wavenumber range of 1627 cm-1 or more and 1647 cm-1 or less. The second absorbance is the highest absorbance in a wavenumber range of more than 1647 cm-1 and 1800 cm-1 or less.