Multi-layer Toner Structure for Transfer Efficiency

The patent applies local quality by creating a multi-layer toner particle structure where the surface layer (layer A) has different properties from the core (main body particle). The surface layer is specifically designed with reduced non-electrostatic adhesive force to improve transfer efficiency, while the core maintains the small particle size needed for high image quality. This localized differentiation resolves the contradiction between small particle size and transfer efficiency.

The patent uses composite materials by combining multiple resin types in a layered structure. Layer A contains resin A particles and layer B contains resin B particles, where these resins are incompatible with the binder resin in the main body. This composite structure allows the surface layers to provide low adhesive force for efficient transfer while the core provides the necessary mechanical properties and small particle characteristics for high-quality image reproduction.

The patent applies preliminary action by pre-forming stable surface layers (A and B) on the toner particles before they undergo mechanical stress during development. These surface layers are specifically engineered to maintain their structure and prevent additive burial under mechanical stress, ensuring that transfer efficiency remains stable over extended periods even in high-speed apparatuses with intensive agitation.

The patent effectively replaces the traditional approach of using external additives (which get buried and失效) with a structural solution where the surface layers themselves provide the low adhesive force property. The surface layers are designed to be mechanically robust and resistant to burial, making them a durable, long-lasting solution rather than a temporary additive approach.