Developing Roller Copolymer Prevents Surface Tackiness and Staining
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Solution Overview
Problem
Existing electrophotographic functional component parts face issues with surface tackiness and staining due to the use of amino compounds as catalysts in urethanation reactions, which also lead to inadequate triboelectric charging and image quality problems in high-speed, high-image quality devices.
Innovation Solution
A copolymer is developed by copolymerizing specific acrylate or methacrylate, amino group-containing, and polar group-containing monomers, which promotes urethanation reactions without amino compounds and prevents surface tackiness and staining, while enhancing triboelectric charging and image density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a low hardness urethane resin is used to achieve good nips, then the flexibility and contact with photosensitive member are improved, but the surface becomes tacky causing toner adhesion
Solution Approach 1:
The patent changes the chemical composition parameters of the urethane resin by incorporating specific copolymers with controlled glass transition temperatures and compositional ratios. This modifies the resin's physical properties to reduce surface tackiness while maintaining low hardness and good nip quality through parameter optimization rather than fundamental material change
Solution Approach 2:
The patent creates a composite urethane resin system by combining base urethane resin with specific copolymers containing amino group-containing monomers and polar group-containing monomers. This composite approach allows the material to simultaneously achieve low hardness for good nips and reduced surface tackiness through the synergistic effects of different polymer components
2Productivity
If an amino compound catalyst is used in urethanation reaction to improve polymerization efficiency, then the resin formation is enhanced, but the amino compound exudes during use causing staining
Solution Approach 1:
The patent extracts and eliminates the harmful amino compound catalyst from the final resin system by using alternative catalysts or catalyst-free methods. The urethanation reaction is designed to proceed without leaving residual catalyst that could exude and cause staining, thereby removing the source of the harmful effect while maintaining reaction efficiency
Solution Approach 2:
The patent introduces an intermediary substance or alternative catalytic system that facilitates the urethanation reaction without the harmful properties of traditional amino compound catalysts. This intermediary approach allows the reaction to proceed efficiently while avoiding the exudation and staining problems associated with conventional catalysts
3Productivity
If high-speed operation is implemented to improve productivity, then the output is increased, but toner deterioration accelerates causing insufficient triboelectric charging
Solution Approach 1:
The patent modifies the surface properties of the developing roller by adjusting the copolymer composition, glass transition temperature, and molecular weight. These parameter changes enhance the triboelectric charging characteristics of the roller surface, allowing it to maintain effective toner charging even under high-speed operating conditions where toner deterioration would otherwise accelerate
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 copolymer effectively prevents surface tackiness and staining, improves triboelectric charging, and maintains high-density images without fogging in high-speed, high-image quality electrophotographic apparatuses over a long period.
Implementation Method 1
to obtain a urethane resin for electrophotographic functional component parts by a urethanation reaction of a polyol component with an isocyanate component
Implementation Method 2
A developing roller as the developing member is required to uniformly and sufficiently triboelectrically charge the toner
Data Source
AI summary
A copolymer obtained by copolymerizing at least one monomer selected from specific acrylate or methacrylate monomers, at least one monomer selected from specific amino group-containing monomers and at least one monomer selected from specific polar group-containing monomers. A resin for electrophotographic functional component parts, which contains this copolymer, a developing roller in which a cover layer serving as a surface layer contains the copolymer as a positive charge control resin, and an electrophotographic apparatus that includes the developing roller.