Aqueous Interfacial Layer Coating for Photoreceptor Adhesion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional photoreceptors face issues with poor adhesion and charge leaking due to the dissolution of interfacial layers during the drying process of charge generation layers, leading to high residual voltage and performance limitations.

Innovation Solution

An aqueous-based coating solution comprising a charge control agent, surfactant, and solvent is used to form a cross-linked interfacial layer through phase inversion emulsification, providing a thin and robust adhesion-promoting layer between the charge blocking and charge generation layers, eliminating the need for organic volatiles and enhancing photoreceptor performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional organic solvent-based coating solution is used to form the interfacial layer, then the coating process is simple, but the interfacial layer dissolves during charge generation layer drying, causing poor adhesion and charge leaking

Engineering Contradiction:

Improveadhesion qualityVSAvoidcoating solution composition

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the fundamental parameter of the coating solution from organic solvent-based to aqueous-based. This parameter change prevents the interfacial layer from dissolving during the drying process, as water and organic solvents are immiscible, thereby eliminating the adhesion problems and charge leaking associated with conventional coating solutions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite coating solution system consisting of aqueous phase (water), organic phase (hydrophobic solvent), and surfactant. This composite material approach allows the formation of a stable emulsion that maintains the interfacial layer's integrity while enabling proper coating and drying processes.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the interfacial layer is made thinner to reduce residual voltage, then charge transport performance improves, but adhesion between layers becomes insufficient

Engineering Contradiction:

Improvecharge transport performanceVSAvoidinterfacial adhesion

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

By changing the coating solution from organic-based to aqueous-based, the patent enables the formation of thin interfacial layers (5-50 nm) that maintain strong adhesion. The aqueous solution prevents dissolution during drying, allowing the interfacial layer to form a robust bonding interface even at minimal thickness, thus achieving both low residual voltage and strong adhesion.

Inventive Principle:

Principle #35Parameter changes

3Strength

If a thick interfacial layer is used to ensure adhesion, then layer bonding improves, but residual voltage increases and charge transport efficiency decreases

Engineering Contradiction:

Improveinterfacial adhesionVSAvoidcharge transport efficiency

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent utilizes the parameter change of using aqueous-based coating solution to achieve strong adhesion with minimal layer thickness. The water-based formulation prevents solvent-induced dissolution, allowing the interfacial layer to form effective bonds at thicknesses of 5-50 nm, eliminating the need for thick layers that would impede charge transport.

Inventive Principle:

Principle #35Parameter changes

4Ease of manufacture

If conventional organic solvent-based coating is used, then coating process is established, but environmental pollution and health hazards occur

Engineering Contradiction:

Improvecoating process establishmentVSAvoidenvironmental pollution

Core Design Contradiction:

Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the solvent parameter from organic to aqueous, replacing harmful organic solvents with water as the continuous phase. This parameter change eliminates environmental pollution and health hazards associated with organic solvents while maintaining the coating process through emulsion technology and controlled drying.

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 results in low discharge residual voltage, stable cycling performance, and improved adhesion, while being environmentally friendly and cost-effective, with the interfacial layer demonstrating excellent electrical properties and resistance to humidity.

Implementation Method 1

An aqueous-based coating solution comprising a charge control agent, surfactant, and solvent is used to form a cross-linked interfacial layer through phase inversion emulsification

Methodology Applied

Scientific EffectPhase inversion emulsification: Emulsion

Implementation Method 2

An aqueous-based coating solution comprising a charge control agent, surfactant, and solvent is used to form a cross-linked interfacial layer

Methodology Applied

Scientific EffectSurfactant action: Surfactant

Data Source

PatentUS8273514B2Interfacial layer and coating solution for forming the same

Publication Date: 2012.09.25 XEROX CORP

AI summary

The present embodiments are generally directed to an improved imaging member exhibiting various advantages over conventional imaging members. More specifically, the present embodiments are directed to an improved interfacial layer formed from an aqueous-based coating solution which exhibits improved formation and coating properties, such as increased homogeneity and adhesion, and methods for making the same. The aqueous-based coating solution is environment-friendly and avoids the need to use more expensive organic solvents which involve higher safety risks in the manufacturing process.