Polyester Urethane Toner for Low-Temperature Fixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing toner technologies face challenges in achieving low-temperature fixability while maintaining high offset resistance and stable charging behavior, particularly with urethane resins, which often result in nonuniform particle size distribution and impaired fixing performance.
Innovation Solution
A toner particle composition comprising polyester as the main resin, colorant, and urethane resin, with controlled hydroxyl value and glass transition temperature ranges, and a nitrogen-containing surface layer to enhance triboelectric charging and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If urethane resin is used to improve low-temperature fixability, then fixing performance at lower temperatures is enhanced, but particle size distribution becomes nonuniform and charging behavior becomes unstable
Solution Approach 1:
The patent changes the chemical composition parameters of the binder resin, specifically using polyester resin with controlled hydroxyl value (15-30 mg KOH/g) and glass transition temperature (40-60°C). These parameter adjustments enable the resin to maintain sharp melting behavior for low-temperature fixing while avoiding the particle size distribution problems associated with urethane resin.
2Reliability
If shell portion is made robust to heating through strong crosslinking or high molecular weight, then heat resistance is improved, but low-temperature fixability is impaired
Solution Approach 1:
The patent applies local quality by creating a core-shell structure where the core contains polyester resin optimized for low-temperature melting and fixing, while the shell provides protective functions. This spatial differentiation allows the core to maintain low-temperature fixability while the overall structure achieves adequate heat resistance.
Solution Approach 2:
The patent uses composite materials by combining polyester resin with specific additives and controlling the resin composition to achieve both low-temperature fixability and heat resistance. The composite binder system includes polyester resin as the main component with controlled molecular weight and hydroxyl value, creating a material that exhibits both sharp melting behavior and thermal stability.
3Manufacturing precision
If toner particle diameter is reduced to increase resolution and definition, then image quality is improved, but transfer efficiency and flowability deteriorate
Solution Approach 1:
The patent emphasizes spherical particle morphology with high circularity (0.96-0.99) to improve flowability and transfer efficiency. The spherical shape compensates for the challenges of small particle diameter by enhancing particle movement characteristics, allowing fine particles to maintain good flow properties and transfer performance while achieving high resolution.
Solution Approach 2:
The patent optimizes the particle size parameter within a specific range (4-9 μm weight-average diameter) and controls the particle size distribution (D90-D10 ≤ 2.0 μm) to balance resolution and transfer efficiency. The narrow size distribution ensures uniform behavior during transfer while maintaining small enough dimensions for high resolution.
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 provides a toner with improved low-temperature fixability, high offset resistance, and stable charging behavior, ensuring precise image definition and reduced contamination, while maintaining excellent heat resistance and transfer efficiency.
Implementation Method 1
a nitrogen-containing surface layer to enhance triboelectric charging
Implementation Method 2
Endowing the binder resin with a sharper melting behavior is already known as an effective method for enabling fixing to occur at lower temperatures. Polyester resins exhibit excellent properties in this regard.
Implementation Method 3
fixing this toner image by the application of heat and pressure
Data Source
AI summary
An object of the present invention is to provide a spherical toner that has a sharp particle size distribution and a small particle diameter. This is a capsule-type toner that exhibits an excellent low-temperature fixability, while at the same time having a high offset resistance and excellent charging properties and having the ability to provide a high-quality image in which the characters, lines, and dots are precisely defined. The object is achieved by a toner comprising a toner particle that comprises at least (a) resin having polyester as the main component, colorant, wax, and (b) urethane resin, wherein the hydroxyl value per specific surface area of the toner particle is fall into the specific range, and wherein a Tg(0.5) and a Tg(4.0)-Tg(0.5) of the toner fall into specific range.