Toner Block Polymer Crystalline Segments Fixing
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Solution Overview
Problem
Toner formulations face challenges in achieving low-temperature fixability with high heat-resistant storage stability, as crystalline polyester toners can lead to hot offset and uneven gloss due to lack of elasticity and inadequate wax dispersibility, resulting in degradation of heat-resistant storage stability upon temperature cycling.
Innovation Solution
A toner composition featuring a binder resin with a block polymer structure, comprising crystalline and non-crystalline segments, and an ester wax with multiple ester bonds, which maintains crystallinity and prevents wax bleedout, ensuring broad fixing latitude and improved heat-resistant storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a crystalline polyester is used alone as the toner binding resin, then low-temperature fixability is improved, but hot offset and decrease in gloss occur due to lack of elasticity at elevated temperatures
Solution Approach 1:
The patent uses a composite binder resin system combining crystalline polyester and non-crystalline polyester in specific proportions (crystalline polyester 30-70 mass%, non-crystalline polyester 30-70 mass%). This composite structure allows the crystalline component to provide sharp melting for low-temperature fixing while the non-crystalline component maintains elasticity at elevated temperatures to prevent hot offset.
Solution Approach 2:
The patent optimizes the melting point of the crystalline polyester to be 60-90°C and controls the storage elastic modulus at the melting point + 20°C to be 10³-10⁵ Pa. By adjusting these parameters within specific ranges, the toner achieves both low-temperature fixability and hot offset resistance.
2Reliability
If a small amount of crystalline polyester is added to non-crystalline polyester, then hot offset is suppressed through viscosity adjustment, but sharp melt properties are not fully exhibited reducing low-temperature fixability
Solution Approach 1:
The patent optimizes the content of crystalline polyester to be 30-70 mass% and controls the viscosity at high temperature to achieve the right balance. This parameter optimization ensures that enough crystalline polyester is present to exhibit sharp melt properties for low-temperature fixing while maintaining adequate viscosity for hot offset resistance.
Solution Approach 2:
The patent creates a dynamic system where the toner exhibits different rheological properties at different temperatures. At fixing temperature, the crystalline polyester melts sharply to enable low-temperature fixing, while at storage temperature, the system maintains appropriate viscosity to prevent hot offset.
3Temperature
If wax is added to improve dispersibility, then low-temperature fixability is enhanced, but wax bleedout occurs reducing heat-resistant storage stability
Solution Approach 1:
The patent controls the wax content to be 1-20 mass% and selects waxes with specific melting points (40-80°C) to balance dispersibility and stability. By optimizing these parameters, the wax provides adequate low-temperature fixability without excessive bleedout that would compromise heat-resistant storage stability.
Solution Approach 2:
The patent uses a releasing agent that mimics the wax's function of improving low-temperature fixability through a different mechanism. The releasing agent (such as silicone oil or fluororesin) provides release properties without the bleedout issues associated with wax, thereby maintaining heat-resistant storage stability.
4Adaptability or versatility
If crystalline polyester and non-crystalline polyester are used in admixture, then fixing latitude is enhanced, but cold offset arises when wax dispersibility is inadequate
Solution Approach 1:
The patent optimizes the melting point of the crystalline polyester to be 60-90°C and controls the content to be 30-70 mass%. This parameter optimization ensures the toner has adequate softening at low temperatures for good fixability while maintaining sufficient structural integrity to prevent cold offset.
Solution Approach 2:
The patent introduces a releasing agent as an intermediary substance to mediate between the toner particles and the substrate. The releasing agent (such as silicone oil or fluororesin) prevents cold offset by providing a release layer that does not interfere with the adhesion of toner to the substrate at low temperatures.
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 excellent low-temperature fixability with enhanced heat-resistant storage stability and reduced cold offset, maintaining image quality across temperature variations.
Implementation Method 1
crystalline polyester resins... do not exhibit a distinct glass transition and do not readily soften up to the crystal melting point
Implementation Method 2
a peak temperature of a maximum endothermic peak derived from the binder resin is at least 50°C and not more than 80°C
Implementation Method 3
the toner has a sharp melting property, but lacks elasticity at elevated temperatures... the storage elastic modulus and loss elastic modulus at the melting point + 20°C
Implementation Method 4
The wax is an ester wax having 3 or more ester bonds as functional groups
Implementation Method 5
wax dispersibility within the toner is inadequate
Data Source
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AI summary
Provided is a toner containing toner particles, each of which includes a binder resin containing a polyester as a main component, a colorant, and a wax, in which the binder resin includes a block polymer in which a segment capable of forming a crystalline structure and a segment incapable of forming a crystalline structure are bonded, the toner has a maximum endothermic peak from the binder resin, as determined by differential scanning calorimetry measurement, with a peak temperature in a specific range and with an endothermic quantity in a specific range, and the wax is an ester wax having a functionality of 3 or more.