Electrostatic Toner Shell Segmentation for Thermal Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrostatic latent image developing toners face challenges in achieving high-temperature preservability and low-temperature fixability while maintaining excellent thermal-stress resistance and fluidity, due to limitations in the structure and composition of their shell layers.
Innovation Solution
The toner particles are designed with a multi-layered shell structure, comprising a first shell layer of monodispersed resin particles and a second shell layer of particle aggregates, where at least 90% of the resin particles have primary and secondary particle diameters between 20-30 nm and 100-150 nm respectively, ensuring comprehensive surface coverage and improved bonding between layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-layer shell structure is used, then the structure is simple, but thermal-stress resistance and low-temperature fixability cannot be simultaneously achieved
Solution Approach 1:
The shell layer is divided into two distinct layers: a first shell layer with resin particles in a non-aggregated state providing thermal-stress resistance, and a second shell layer with particle aggregates providing low-temperature fixability. This segmentation allows each layer to perform its specific function independently, resolving the contradiction between reliability and structural simplicity.
Solution Approach 2:
The invention uses composite shell structures combining two different resin particle configurations (non-aggregated and aggregated states) in specific proportions. This composite approach enables simultaneous achievement of thermal-stress resistance and low-temperature fixability, which cannot be obtained with a single homogeneous shell structure.
2Temperature
If resin particles are in aggregated state, then low-temperature fixability improves, but thermal-stress resistance deteriorates
Solution Approach 1:
Different regions of the shell layer have different qualities: the first shell layer contains resin particles in a non-aggregated state optimized for thermal-stress resistance, while the second shell layer contains particle aggregates optimized for low-temperature fixability. This local differentiation allows each region to perform its specific function without compromising the other.
3Reliability
If resin particles are in non-aggregated state, then thermal-stress resistance improves, but low-temperature fixability deteriorates
Solution Approach 1:
The shell layer is segmented into two functional layers where the first shell layer with non-aggregated resin particles provides thermal-stress resistance, while the second shell layer with aggregated particles provides low-temperature fixability. This segmentation resolves the contradiction by assigning different particle states to different layers.
4Reliability
If shell layer coverage is increased, then high-temperature preservability improves, but fluidity deteriorates
Solution Approach 1:
The invention optimizes the coverage proportion of the second shell layer (particle aggregates) to be within 5-15%, and controls the primary particle diameter of resin particles to be 20-30 nm. These parameter changes ensure sufficient surface coverage for high-temperature preservability while maintaining adequate fluidity for image formation.
Data Source
AI summary
An electrostatic latent image developing toner includes toner particles each including a core and a shell layer. The shell layer is a collection of resin particles having the same composition (primary particle diameter of at least 90% by number of the resin particles: 20 nm-30 nm). The shell layer includes a first shell layer, which is a film including the resin particles in a non-aggregated state, and a second shell layer, which is a plurality of particle aggregates (secondary particle diameter of at least 90% by number of the particle aggregates: 100 nm-150 nm). The particle aggregates each include the resin particles in an aggregated state. The surface of the core is entirely covered with the shell layer. The second shell layer is present in a surface of the toner particle in a proportion of at least 5% by area and no greater than 15% by area.