Undercoat Layer Moisture Migration for Fogging Suppression

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Solution Overview

Problem

Existing electrophotographic photoreceptors face challenges in suppressing electric potential changes and fogging during long-term repeated use, leading to increased toner consumption, especially in high-temperature, high-humidity environments.

Innovation Solution

The electrophotographic photoreceptor is designed with a support, an undercoat layer containing titanium oxide particles surface-treated with specific organosilicon compounds, and a charge generation layer with hydroxygallium phthalocyanine, which enhances moisture migration and prevents local charge injection, thereby reducing fogging and electric potential fluctuations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional undercoat layers with polyamide resin and surface-treated titanium oxide are used, then adhesion and electrostatic stability are improved, but electric potential changes and fogging occur during long-term repeated use in high-temperature, high-humidity environments

Engineering Contradiction:

Improveelectrostatic stabilityVSAvoidfogging and electric potential changes

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the undercoat layer by incorporating specific organosilicon compounds (with particular molecular structures containing alkoxy groups) alongside polyamide resin and titanium oxide. This parameter change modifies the layer's hydrophobicity and moisture migration characteristics, suppressing fogging and electric potential changes during long-term use in high-temperature, high-humidity environments while maintaining adhesion and electrostatic stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite undercoat layer material combining polyamide resin, surface-treated titanium oxide particles, and specific organosilicon compounds. This composite structure leverages the adhesion properties of polyamide, the electrostatic stability of titanium oxide, and the moisture-resistant characteristics of organosilicon compounds to simultaneously achieve both improved reliability and reduced harmful effects.

Inventive Principle:

Principle #40Composite materials

2Strength

If titanium oxide particles are surface-treated to adjust hydrophobicity, then adhesion is improved, but moisture migration and charge accumulation still occur leading to fogging

Engineering Contradiction:

ImproveadhesionVSAvoidcharge accumulation and fogging

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the surface treatment parameters of titanium oxide particles by applying specific organosilicon compounds with defined molecular structures (containing alkoxy groups and specific R groups). This changes the surface hydrophobicity parameter to optimize both adhesion strength and moisture migration resistance, preventing charge accumulation and fogging while maintaining strong adhesion.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The organosilicon compound acts as an intermediary substance between the titanium oxide particles and the polyamide resin matrix. It mediates the interaction by providing both adhesion promotion (through reactive groups) and moisture resistance (through hydrophobic alkyl chains), thereby preventing charge accumulation and fogging while maintaining strong adhesion.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This configuration effectively suppresses fogging and electric potential changes, resulting in reduced toner consumption and improved image quality by ensuring uniform dispersion and hydrophobicity of titanium oxide particles and minimizing charge accumulation.

Implementation Method 1

enhances moisture migration and prevents local charge injection

Methodology Applied

Scientific EffectMoisture migration: Diffusion

Implementation Method 2

titanium oxide particles surface-treated with an organosilicon compound... ensuring uniform dispersion and hydrophobicity

Methodology Applied

Scientific EffectHydrophobicity: Hydrophobe

Data Source

PatentUS11086241B2Electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus

Publication Date: 2021.08.10 CANON KK

AI summary

An electrophotographic photoreceptor includes a support, an undercoat layer placed on the support, a charge generation layer placed on the undercoat layer, and a charge transport layer placed on the charge generation layer. The undercoat layer contains titanium oxide particles surface-treated with an organosilicon compound that is at least one member selected from the group consisting of compounds represented by formulas (1) to (8) and a polyamide resin. The charge generation layer contains hydroxygallium phthalocyanine.