Electrophotographic Photoreceptor Interfacial Adhesion
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Solution Overview
Problem
In lamination type electrophotographic photoreceptors, the surface protective layer tends to peel off or float from the charge transport layer when its thickness is reduced, due to low adhesiveness at the interface between the two layers.
Innovation Solution
The electrophotographic photoreceptor includes a conductive substrate, an undercoat layer, a charge generation layer, a charge transport layer containing a specific polyester resin with dicarboxylic acid and diol units, and a surface protective layer formed with a curing agent containing guanamine or melamine compounds and reactive group-containing charge transport materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the thickness of the surface protective layer is reduced, then the surface free energy and toner adhesion are improved, but the layer becomes prone to peeling and floating due to low interfacial adhesiveness
Solution Approach 1:
The invention changes the chemical composition parameters of the charge transport layer by incorporating specific polyester resins with hydroxyl groups and polyfunctional isocyanates, which alters the interfacial chemical properties and enhances adhesiveness to the surface protective layer even when the layer is thin
Solution Approach 2:
The invention uses a composite material system where the charge transport layer combines polyester resin, polyfunctional isocyanate, and charge transport material, creating a multi-component system that provides both the desired surface free energy characteristics and strong interfacial bonding capability
2Reliability
If a lamination type structure with surface protective layer is used, then the photoreceptor durability is improved, but the complexity of the layer structure and manufacturing process increases
Solution Approach 1:
The invention merges the functional requirements of multiple layers into the charge transport layer by incorporating adhesion-promoting components (polyester resin and polyfunctional isocyanate) that enable strong bonding to the surface protective layer, effectively combining the roles of structural support and interfacial bonding in one layer
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 enhances the adhesiveness between the surface protective layer and the charge transport layer, preventing peeling or floating even when the surface protective layer's thickness is reduced.
Implementation Method 1
a surface protective layer which is a cured film with a composition containing a curing agent which contains at least one of a guanamine compound or a melamine compound, and at least one reactive group-containing charge transport material
Implementation Method 2
a charge transport layer containing a specific polyester resin with dicarboxylic acid and diol units
Data Source
AI summary
An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer that is provided on the conductive substrate, a charge generation layer that is provided on the undercoat layer, a charge transport layer that is provided on the charge generation layer and contains a polyester resin (1) having a dicarboxylic acid unit (A) represented by Formula (A) and a diol unit (B) represented by Formula (B) and a charge transport material, and a surface protective layer that is provided on the charge transport layer and is a cured film with a composition containing a curing agent which contains at least one of a guanamine compound or a melamine compound, and at least one reactive group-containing charge transport material having at least one substituent selected from the group consisting of —OH, —OCH3, —NH2, —SH, and —COOH,in Formula (A), n1 represents 1, 2, or 3, n1 pieces of m1's each independently represent 0, 1, 2, 3, or 4, m1 pieces of Ra1's each independently represent an alkyl group having 1 or more and 10 or less carbon atoms, an aryl group having 6 or more and 12 or less carbon atoms, or an alkoxy group having 1 or more and 6 or less carbon atoms,in Formula (B), Rb1 and Rb2 each independently represent a hydrogen atom, an alkyl group having 1 or more and 20 or less carbon atoms, an aryl group having 6 or more and 12 or less carbon atoms, or an aralkyl group having 7 or more and 20 or less carbon atoms, Rb3, Rb4, Rb5, Rb6, Rb7, Rb8, Rb9, and Rb10 each independently represent a hydrogen atom, an alkyl group having 1 or more and 10 or less carbon atoms, an aryl group having 6 or more and 12 or less carbon atoms, an aralkyl group having 7 or more and 20 or less carbon atoms, or an alkoxy group having 1 or more and 6 or less carbon atoms, and Rb1 and Rb2 may be bonded to each other to form a cyclic alkyl group.