Toner Composition with Crystalline Polyester for Low-Temperature Fixing
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Solution Overview
Problem
Conventional toner production methods, such as kneading and pulverizing, face challenges in achieving small particle size, uniform particle distribution, and high low-temperature fixing ability while maintaining heat-resistant storage stability and image gloss, with issues like toner deposition and hot offset resistance.
Innovation Solution
A toner composition comprising a binder resin with a non-linear chain non-crystalline polyester resin, a non-crystalline polyester resin, and a crystalline polyester resin, with specific glass transition temperatures and storage moduli, allowing for improved low-temperature fixing, heat-resistant storage stability, and image gloss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a toner is produced by the kneading and pulverizing method, then it can be manufactured with conventional processes, but the particle size cannot be reduced sufficiently and the particle shape is uneven with broad diameter distribution
Solution Approach 1:
The patent changes the fundamental production parameter from mechanical pulverization to chemical polymerization, enabling precise control of particle size and shape through polymerization conditions while achieving uniform spherical particles with narrow diameter distribution
Solution Approach 2:
The patent utilizes the phase transition of the releasing agent (wax) from solid to liquid during the polymerization process, allowing the wax to be encapsulated within the toner particles during formation, thereby achieving uniform particle structure without subsequent pulverization
2Reliability
If wax is added to improve fixing ability, then low temperature fixing ability is improved, but the toner causes deposition on carrier, photoconductor, and blade
Solution Approach 1:
The patent performs preliminary encapsulation of the releasing agent (wax) within the toner particle structure during the polymerization process, creating a core-shell structure where the wax is contained inside. This prevents the wax from migrating to surfaces and causing deposition while maintaining its low-temperature fixing functionality
Solution Approach 2:
The patent creates a nested structure where the releasing agent (wax) is embedded within the toner binder resin matrix. The wax core is surrounded and contained by the polymer shell, preventing surface migration and deposition while preserving the releasing effect during fixation
3Reliability
If a crystalline polyester resin is used to achieve low temperature fixing, then fixing ability is improved, but aggregates form in high-temperature, high-humidity environment
Solution Approach 1:
The patent creates a composite toner structure combining crystalline polyester resin (for low-temperature fixing) with non-crystalline polyester resin and releasing agent. The non-crystalline resin matrix and encapsulated wax prevent aggregate formation in humid environments while the crystalline resin provides rapid melting and low-temperature fixing ability
4Manufacturing precision
If small particle size is achieved for high quality output, then image quality is improved, but more energy is required for fixing
Solution Approach 1:
The patent utilizes the phase transition (melting) of the crystalline polyester resin at low temperature to achieve rapid viscosity reduction and efficient fixing of small particles. The crystalline structure enables sharp melting behavior that reduces the energy required for fixing compared to amorphous resins
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 fixing ability, heat-resistant storage stability, and image gloss, while preventing toner deposition and hot offset resistance issues.
Implementation Method 1
the toner has a glass transition temperature [Tg1st (toner)] of 20°C to 50°C, where the glass transition temperature [Tg1st (toner)] is measured in a first heating in differential scanning calorimetry (DSC) of the toner
Implementation Method 2
tetrahydrofuran (THF) insoluble matter of the toner has a glass transition temperature [Tg2nd (THF insoluble matter)] of -40°C to 30°C, where the glass transition temperature [Tg2nd (THF insoluble matter)] is measured in a second heating in differential scanning calorimetry (DSC) of the tetrahydrofuran (THF) insoluble matter
Implementation Method 3
as the crystalline polyester resin is rapidly melted, compared to a non-crystalline polyester resin
Data Source
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AI summary
A toner, wherein the toner has glass transition temperature [Tg1st (toner)] of 20°C to 50°C, where the glass transition temperature [Tg1st (toner)] is measured in a first heating in differential scanning calorimetry (DSC) of the toner, wherein tetrahydrofuran (THF) insoluble matter of the toner has glass transition temperature [Tg2nd (THF insoluble matter)] of -40°C to 30°C, where the glass transition temperature [Tg2nd (THF insoluble matter)] is measured in a second heating in differential scanning calorimetry (DSC) of the tetrahydrofuran (THF) insoluble matter, wherein the THF insoluble matter has a storage modulus at 100°C [G'(100) (THF insoluble matter)] of 1.0x105Pa to 1.0x107Pa, and wherein a ratio of a storage modulus of the THF insoluble matter at 40°C [G'(40) (THF insoluble matter)] to the storage modulus of the THF insoluble matter at 100°C [G'(100) (THF insoluble matter)] is 3.5x10 or less.