Toner Particle Core-Shell Structure for Transfer and Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing toners face challenges in maintaining high transferability and cleaning performance while preventing melt adhesion and contamination issues during long-term use at high speeds and in low-temperature, low-humidity environments, where shear forces are strong.
Innovation Solution
A toner with a specific particle size distribution and the addition of an organosilicon polymer fine particle, which reduces non-static attachment force and maintains elasticity to prevent embedding and promote spacer functionality between toner particles, ensuring stable transferability and cleaning performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If toner particles with larger diameter are used to reduce attachment force and improve transferability, then transferability is improved, but cleaning performance deteriorates due to stronger shear forces causing melt adhesion in low-temperature, low-humidity environments
Solution Approach 1:
The invention applies local quality by creating a core-shell structure where the toner particle has different properties in different regions: the core provides the base toner properties while the shell layer (comprising 5-50 mass% of the total toner) provides specific functional properties including controlled attachment force, reduced melt adhesion, and improved cleaning performance. This shell structure allows the toner to exhibit different characteristics at different locations within the particle.
Solution Approach 2:
The invention uses composite materials by combining multiple resin components in the toner particle structure. The toner consists of a core resin and a shell resin with specific glass transition temperatures and molecular weight ratios, creating a composite material that exhibits both improved transferability (through controlled attachment force) and reduced melt adhesion (through the shell's protective function). The composite structure integrates the benefits of different materials to resolve the contradiction.
2Object-generated harmful factors
If toner particles with smaller diameter are used to improve cleaning performance through weaker attachment force, then cleaning performance is improved, but transferability deteriorates due to insufficient detachment from photosensitive drum
Solution Approach 1:
The shell layer in the core-shell structure provides localized functional properties that improve cleaning performance while maintaining transferability. The shell comprises specific resin components with controlled glass transition temperatures that create optimal attachment force characteristics for both transfer and cleaning operations.
Solution Approach 2:
The invention changes physical parameters by controlling the glass transition temperature of the shell resin (Tg2) to be higher than the core resin (Tg1), and by controlling the molecular weight ratio (Mw2/Mw1) between 0.1 and 10. These parameter changes create a toner particle with optimized attachment force characteristics that enable both good transferability and cleaning performance.
3Reliability
If classification is used to remove small-diameter toner particles to improve transferability, then transferability is improved, but long-term stability deteriorates due to cleaning problems and image defects from melt adhesion at high speeds
Solution Approach 1:
The composite core-shell structure provides long-term stability by incorporating a shell layer that protects against melt adhesion and cleaning problems. The specific resin composition and molecular weight ratio in the shell prevent the toner from degrading under high-speed, low-temperature, low-humidity conditions, ensuring consistent performance over time.
Solution Approach 2:
By controlling the glass transition temperature difference (Tg2 > Tg1) and molecular weight ratio (0.1 ≤ Mw2/Mw1 ≤ 10) between core and shell, the invention creates a toner particle with enhanced thermal and mechanical stability. These parameter changes prevent melt adhesion and cleaning blade embedding even during prolonged high-speed operation.
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 toner achieves stable transferability and cleaning performance, preventing melt adhesion and contamination even during prolonged use in harsh environments, thereby enhancing durability and image quality.
Implementation Method 1
it is necessary to reduce the attachment force between the photosensitive drum and the toner
Implementation Method 2
maintains elasticity to prevent embedding and promote spacer functionality between toner particles
Data Source
AI summary
A toner including a toner particle containing a binder resin, and an external additive, wherein the external additive contains an organosilicon polymer fine particle, the organosilicon polymer has a structure represented by at least one selected from the group consisting of RaSiO3/2 and Rb2SiO2/2 (wherein Ra and Rb represent organic groups), and in the number particle size distribution of the toner as measured within a particle size range of from 2 to 60 µm, the number-average particle diameter T-D50n at which the accumulation from the smallest diameter is 50% is from 6 to 12 µm, the number ratio of toner 4 µm or less in size is from 2% to 5% of the total toner, and the number ratio of toner 3 µm or less in size as a percentage of the total toner 4 µm or less in size is from 25% to 50%.