Electro-conductive Roller Surface Layer for Charge Control
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Solution Overview
Problem
Electro-conductive rollers in electrophotographic systems face issues with excessive charge accumulation and fogging, especially in varying environments, due to the insulation properties of silica-based surface coatings, leading to poor image quality and adhesion of toner and developer powders.
Innovation Solution
An electro-conductive member with a substrate, elastic layer, and a surface layer containing a non-phase-separated matrix of urethane resin and silicon oxide, which provides conductivity and triboelectricity, preventing charge accumulation and adhesion, and maintaining image quality across different environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a silica-based surface coating is applied to the electro-conductive roller, then the adhesion of toner and developer powder is reduced, but excessive charge accumulation and fogging occur due to insulation properties
Solution Approach 1:
The surface coating is formed as a composite material containing both silica particles (for reducing toner adhesion) and conductive rubber (for maintaining electroconductivity). This composite structure resolves the contradiction by combining the adhesion-reducing properties of silica with the charge-dissipating properties of conductive rubber, preventing both excessive adhesion and charge accumulation.
Solution Approach 2:
The invention changes the electrical conductivity parameter of the surface coating by incorporating conductive rubber into the silica-based coating. This parameter modification allows the coating to maintain both low surface energy (for reducing adhesion) and sufficient electroconductivity (for preventing charge accumulation), thereby resolving the contradiction between adhesion reduction and charge control.
2Object-generated harmful factors
If a polysilazane surface coating is applied to reduce stickiness, then toner adhesion is reduced, but fogging occurs in high-temperature and high-humidity environments
Solution Approach 1:
The surface coating combines polysilazane (for low stickiness) with conductive rubber particles (for environmental stability and charge dissipation). This composite approach maintains the low surface energy properties of polysilazane while adding the environmental resilience and electroconductivity of conductive rubber, preventing fogging in high-temperature and high-humidity conditions.
Solution Approach 2:
The invention modifies the electrical conductivity parameter of the polysilazane coating by incorporating conductive rubber, enabling the coating to maintain its low-stickiness properties while gaining sufficient electroconductivity to prevent charge accumulation and fogging in varying environmental conditions.
3Object-generated harmful factors
If the surface coating has high insulation properties to prevent adhesion, then toner sticking is reduced, but charge-up occurs leading to poor image quality
Solution Approach 1:
The surface coating is designed as a composite with silica particles (for reducing toner sticking) dispersed in a conductive rubber matrix (for preventing charge-up). This composite structure achieves both low surface energy for adhesion reduction and sufficient electroconductivity for charge dissipation, thereby maintaining high image quality without excessive toner sticking.
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 effectively suppresses fogging and toner adhesion, ensuring stable and high-quality electrophotographic images under diverse environmental conditions by preventing charge-up and maintaining surface conductivity.
Implementation Method 1
an electro-conductive surface layer covering a surface of the elastic layer. The electro-conductive surface layer contains a matrix in which a urethane resin and a silicon oxide exist in a non-phase-separated state
Implementation Method 2
an electro-conductive roller wherein a surface coating film containing a polysilazane is formed thereon can prevent unnecessary adhesion of a toner because of a low stickiness of the roller surface
Data Source
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AI summary
An electro-conductive member for electrophotography contributing to stable formation of high-quality electrophotographic images under a variety of environments is provided. The electro-conductive member has an electro-conductive substrate, an elastic layer on the substrate, and an electro-conductive surface layer covering a surface of the elastic layer, wherein the electro-conductive surface layer contains a matrix in which a urethane resin and a silicon oxide exist in a non-phase-separated state, and the matrix has a peak of a Si-N bond derived from a polysilazane in a wavelength region from 800 cm-1 or higher and 950 cm-1 or lower in an infrared absorption spectrum of the matrix.