Electrophotographic Member Surface Layer IPN Structure
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Solution Overview
Problem
Electrophotographic members used in electrophotographic image forming apparatuses degrade over time, leading to reduced durability and performance, which affects the quality and stability of formed images.
Innovation Solution
An electrophotographic member with a surface layer comprising a crosslinked urethane resin and a crosslinked acrylic resin forming an interpenetrating polymer network structure, combined with carbon black having a volatile content of 0.4% or more, is developed to enhance mechanical strength and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional surface layer is used in electrophotographic members, then the initial performance is acceptable, but the performance degrades significantly over time due to mechanical wear and environmental factors
Solution Approach 1:
The surface layer employs a composite structure consisting of a rubber elastic body base material combined with a cured photocurable composition surface layer. This composite material approach integrates the elasticity and shock absorption of rubber with the hardness and wear resistance of the cured photocurable resin, creating a surface layer that resists mechanical wear and maintains performance over extended service life.
Solution Approach 2:
The patent modifies the chemical composition and physical properties of the surface layer by using a photocurable composition containing specific monomers and oligomers. The curing process transforms the liquid or soft precursor materials into a hard, crosslinked network structure, fundamentally changing the surface properties to achieve superior durability and wear resistance while maintaining initial performance characteristics.
2Strength
If the surface layer is made harder to improve wear resistance, then durability increases, but toner releasability and low friction properties deteriorate
Solution Approach 1:
The surface layer exhibits local quality differentiation through its composite structure. The cured photocurable composition provides a hard, wear-resistant outer surface, while the underlying rubber elastic body maintains softness and elasticity. This gradient structure allows the surface to resist wear while the bulk material provides low friction and good toner releasability, resolving the contradiction between hardness and friction.
Solution Approach 2:
The patent carefully controls the composition of the photocurable composition, including the types and ratios of monomers, oligomers, and crosslinking agents, to achieve optimal surface properties. By adjusting these chemical parameters, the surface layer attains sufficient hardness for wear resistance while maintaining appropriate surface energy and friction characteristics for toner handling.
3Strength
If a single-material surface layer is used, then the structure is simple and easy to manufacture, but it cannot simultaneously achieve high strength, elasticity, and wear resistance
Solution Approach 1:
The surface layer is constructed as a composite of a rubber elastic body and a cured photocurable composition. This composite structure combines the advantageous properties of both materials: the rubber provides elasticity and shock absorption, while the cured photocurable resin contributes hardness, strength, and wear resistance. The composite approach achieves superior mechanical properties without requiring complex multi-layer structures.
Solution Approach 2:
The photocurable composition is applied to the rubber elastic body surface and then cured in advance to form a permanent, integrated surface layer. This preliminary action of curing creates a stable, pre-formed surface structure that combines the benefits of both materials, eliminating the need for complex assembly or post-processing steps during manufacturing.
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 significantly improves the mechanical strength and durability of the electrophotographic member, maintaining high performance even under high temperature environments, thereby ensuring stable and high-quality image formation over long-term use.
Implementation Method 1
the crosslinked urethane resin and the crosslinked acrylic resin form an interpenetrating polymer network structure
Implementation Method 2
the carbon black has a volatile content of 0.4% or more... maintaining high performance even under high temperature environments
Implementation Method 3
a surface treated layer composed of a cured product of a photocurable composition impregnated from a surface of the rubber elastic body
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
There is provided an electrophotographic member which suppresses scraping and contamination of a surface even in the durable use of multiple sheet printing under a high temperature environment. The electrophotographic member has an electroconductive substrate (2) and a single elastic layer (1) as a surface layer, the surface layer includes a binder resin and carbon black dispersed in the binder resin, the carbon black has a volatile content of 0.4% or more, the binder resin includes a crosslinked urethane resin and a crosslinked acrylic resin, and the surface layer has a first area (41) in which the crosslinked urethane resin (501) and the crosslinked acrylic resin (502) form an interpenetrating polymer network structure, the first area being from an outer surface of the surface layer to a depth of 0.1 µm in the surface layer.