Developing Member Adhesion via Organopolysiloxane Mediator
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing developing members in electrophotographic apparatuses using a one-component toner system face issues with adhesiveness degradation between the electro-conductive elastic layer and the urethane resin layer, leading to interfacial peeling, and compromised conductivity due to the use of silane coupling agents.
Innovation Solution
A developing member configuration featuring a mandrel with an elastic layer composed of a cured addition polymerization type silicone rubber composition, including an organopolysiloxane with specific molecular weight and functional groups, and a resin layer formed from a polyurethane resin, which enhances adhesiveness without impairing conductivity by allowing carbon black to maintain its electro-conductive path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a silane coupling agent is used to enhance adhesive strength between the silicone rubber layer and urethane resin layer, then adhesive strength is improved, but electrical conductivity of the silicone rubber layer is degraded
Solution Approach 1:
The patent introduces a specific organopolysiloxane compound as an intermediary substance between the silicone rubber layer and urethane resin layer. This intermediary contains both silane coupling agent functionality for adhesion and sufficient molecular weight (18,000-110,000) to maintain electrical conductivity pathways through the carbon black network, thus mediating between the conflicting requirements of adhesive strength and conductivity.
Solution Approach 2:
The patent changes the molecular weight parameter of the organopolysiloxane to a specific range (18,000-110,000) and controls the molecular weight distribution (Mw/Mn ≤ 2.0). This parameter optimization allows the material to provide adequate adhesion while maintaining sufficient electrical conductivity by preserving carbon black pathway continuity.
2Duration of action of stationary object
If the elastic layer and resin layer are laminated for long-term use, then structural integrity is improved, but adhesiveness between layers degrades causing interfacial peeling
Solution Approach 1:
The patent incorporates the organopolysiloxane compound with isocyanate-reactive functional groups directly into the silicone rubber composition before layer formation. This preliminary incorporation ensures that adhesion-promoting chemical bonds are already established at the interface before the urethane resin layer is applied, preventing subsequent peeling during long-term service.
Solution Approach 2:
The patent creates a composite material system where the silicone rubber elastic layer contains dispersed organopolysiloxane compounds with specific molecular weights and functional groups. This composite structure provides both the mechanical properties of silicone rubber and enhanced interfacial bonding capability with the urethane resin layer, maintaining adhesion over extended service periods.
3Reliability
If carbon black is dispersed in silicone rubber to provide conductivity, then electrical conductivity is improved, but the formation of continuous conductive pathways is disrupted by adhesive promoters
Solution Approach 1:
The patent optimizes the molecular weight parameter of the organopolysiloxane to be sufficiently high (18,000-110,000) so that the adhesive promoter molecules are large enough to not interfere with carbon black particle aggregation and continuous pathway formation. The controlled molecular weight distribution (Mw/Mn ≤ 2.0) ensures uniform behavior and prevents disruption of conductive networks.
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 ensures firm adhesion between the silicone rubber and urethane resin layers while maintaining appropriate electrical resistance, preventing fogging and ensuring high-quality electrophotographic images.
Implementation Method 1
the elastic layer comprises a cured product of an addition polymerization type silicone rubber composition
Implementation Method 2
the resin layer comprises a polyurethane resin obtained by reacting an isocyanate compound with a polyol compound
Implementation Method 3
an electro-conductive elastic layer containing carbon black and silicone rubber
Data Source
AI summary
Provided is a developing roller including elastic layer and resin layer adhered to each other and having an appropriately resistance, thereby suppressing fogging. The developing member comprises a mandrel; an elastic layer; and a resin layer, wherein: the resin layer comprises polyurethane resin obtained by isocyanate and polyol; and the elastic layer includes cured silicone rubber composition comprising (a)-(d):(a) organopolysiloxane having two or more alkenyl groups bonded to silicon atom and having methyl group as a group other than the alkenyl bonded to the silicon;(b) organopolysiloxane having three or more hydrogen atoms bonded to silicon atom and having methyl group as a group bonded to the silicon;(c) carbon black;(d) organopolysiloxane represented by formula (1) and having Mw of 18,000-110,000 and Mw/Mn of 1.0-2.0 (R1 represents alkenyl group, R2 represents functional group reacting with isocyanate, and n represents an integer of 1 or more).