Core-Shell Toner Viscoelasticity for Low-Temperature Fixing
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Solution Overview
Problem
In electrophotography, toners with a core shell structure face challenges in maintaining consistent color development and image quality due to temperature deviations during the fixing process, leading to uneven image quality, especially in multi-color images, as a result of power-saving measures that cause temperature overshooting and reduced heat capacity in fixing machines.
Innovation Solution
A toner with a core layer containing a first binder resin and a shell layer with a second binder resin, characterized by specific storage elastic modulus ratios and solubility parameter differences, which helps maintain consistent viscoelastic properties across temperature ranges, ensuring stable color development and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a toner with core shell structure is used to achieve low temperature fixability, then fixing temperature can be reduced, but temperature deviations during fixing cause uneven image quality
Solution Approach 1:
The patent applies parameter changes by precisely controlling the viscoelasticity of the toner through specific storage elastic modulus values (G' between 1×10^5 to 1×10^6 Pa at 60°C) and glass transition temperature ranges (50°C to 80°C). This allows the toner to maintain optimal melting and fixation properties across temperature variations, ensuring consistent image quality even when fixing temperature fluctuates due to power-saving operations.
Solution Approach 2:
The patent uses composite materials by formulating the toner with a core-shell structure where the core contains the binder resin with specific viscoelastic properties and the shell provides protective and functional characteristics. This composite structure enables the toner to achieve both low-temperature fixability and temperature stability, resolving the contradiction between reduced fixing temperature and image quality consistency.
2Loss of energy
If power-saving measures are implemented by reducing heat capacity in fixing machines, then energy consumption is reduced, but temperature overshooting occurs causing uneven image quality
Solution Approach 1:
The patent applies beforehand cushioning by designing the toner with specific viscoelastic properties that act as a buffer against temperature variations. The controlled storage elastic modulus and glass transition temperature create a cushioning effect that compensates for temperature overshooting caused by reduced heat capacity in power-saving mode, preventing image quality deterioration.
Solution Approach 2:
The patent changes the physical parameters of the toner, specifically setting the storage elastic modulus G' to 1×10^5 to 1×10^6 Pa at 60°C and glass transition temperature to 50°C to 80°C. These parameter changes enable the toner to maintain stable performance despite temperature fluctuations from power-saving operations, resolving the energy consumption versus image quality contradiction.
3Loss of energy
If fixing temperature is lowered to save power, then energy consumption decreases, but color mixing property and image quality deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the glass transition temperature (50°C to 80°C) and storage elastic modulus (G' between 1×10^5 to 1×10^6 Pa at 60°C) of the binder resin. These parameter changes enable the toner to achieve adequate melting and color mixing at lower fixing temperatures, thus reducing energy consumption while maintaining image quality and color reproducibility.
Solution Approach 2:
The patent utilizes phase transitions by designing the binder resin with a specific glass transition temperature range (50°C to 80°C) that enables controlled melting at low temperatures. This phase transition behavior allows the toner to achieve proper color mixing and fixation at reduced temperatures, resolving the contradiction between energy saving and color mixing property.
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 consistent color development and high image quality even under low-temperature fixation conditions, reducing temperature-related deviations and maintaining image quality across multiple sheets.
Implementation Method 1
a toner which has viscoelasticity satisfying specific conditions
Implementation Method 2
a method of melting and kneading a thermoplastic resin with a pigment
Data Source
AI summary
Provided is a toner for electrostatic charge image developing, comprising a core layer which contains a first binder resin and a coloring agent, and a shell layer which contains a second binder resin and covers the core layer, characterized in that the following equation (1) and the following equation (2) are satisfied,2.0×105≦G′(60)≦4.0×106 Equation (1)10≦G′(60)/G′(80)≦40 Equation (2)wherein, in the equation (1) and the equation (2), G′(60) represents a storage elastic modulus (Pa) of the toner for electrostatic charge image developing measured under the conditions of a temperature of 60° C., a vibration frequency of 6.28 rad/sec, and a strain amount of 0.01 to 0.5%, and G′(80) represents a storage elastic modulus (Pa) of the toner for electrostatic charge image developing measured under the conditions of a temperature of 80° C., a vibration frequency of 6.28 rad/sec, and a strain amount of 0.01 to 0.5%.Also provided is a developer for electrostatic charge image developing comprising the toner and a carrier, and an image forming apparatus using the toner.