Liquid Developer Core-Shell Toner Fixability
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Solution Overview
Problem
Current liquid developers for electrophotography and inkjet printers face challenges in achieving high fixability across a wide temperature range and maintaining stability during storage, particularly when exposed to high temperatures and humidity, with existing solutions not adequately addressing high-temperature offset issues.
Innovation Solution
A liquid developer with toner particles having a core-shell structure, where the shell resin is attached to a core resin with an acid group and an acid dissociation constant between 2.90 and 8.00, improving fixability and storage characteristics by enhancing adhesion to various recording materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fatty acid monoester is added to plasticize polyester resin, then fixability to paper is improved, but fixability deteriorates during storage in high temperature and humidity environments
Solution Approach 1:
The patent employs a composite resin system combining polyester resin with polyolefin resin in specific proportions (polyester resin 30-70 mass%, polyolefin resin 70-30 mass%). This composite structure integrates the paper-adhesion benefits of polyester resin with the thermal stability and storage resistance of polyolefin resin, resolving the contradiction between initial fixability and storage stability.
Solution Approach 2:
The patent modifies the chemical composition parameters of the resin particles by controlling the ratio of polyester to polyolefin resins and adjusting the glass transition temperature range (0°C to 100°C). This parameter optimization enables the toner to maintain appropriate adhesion properties across varying storage conditions while preserving fixability performance.
2Use of energy by moving object
If heat roller temperature control is simplified or frequency decreased, then energy consumption is reduced, but temperature variation increases causing high-temperature offset
Solution Approach 1:
The patent adjusts the glass transition temperature range of the resin particles (0°C to 100°C) and optimizes the resin composition ratios to enhance thermal stability. These parameter changes enable the toner to maintain stable adhesion properties across wider temperature variations, preventing high-temperature offset even when heat roller temperature control is simplified.
Solution Approach 2:
The composite resin system combining polyester and polyolefin resins provides inherent thermal stability that compensates for temperature fluctuations. The polyolefin component specifically contributes to high-temperature resistance, allowing reliable fixation quality without requiring complex temperature control mechanisms.
3Reliability
If polyester resin is plasticized with fatty acid monoester, then fixability to paper improves, but toner particles shed during storage
Solution Approach 1:
The patent creates a balanced composite system where polyester resin (30-70 mass%) provides paper adhesion through fatty acid monoester plasticization, while polyolefin resin (70-30 mass%) contributes particle strength and cohesion. This composite structure prevents toner particle shedding during storage while maintaining fixability.
Solution Approach 2:
The patent optimizes the glass transition temperature range (0°C to 100°C) and resin composition ratios to achieve the right balance between adhesion and cohesion. By controlling these parameters, the toner particles maintain sufficient internal strength to prevent shedding while retaining surface adhesion properties for effective fixation.
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 liquid developer exhibits excellent fixability on materials like bond paper across a wide temperature range and shows minimal deterioration during storage, ensuring reliable performance in diverse environmental conditions.
Implementation Method 1
the core resin (b) has an acid group and an acid dissociation constant not smaller than 2.90 and not greater than 8.00
Data Source
AI summary
A liquid developer in which toner particles are dispersed in an insulating liquid, the toner particles having such a core-shell structure that shell particles containing a shell resin are attached to or cover surfaces of core particles containing a core resin, the core resin having an acid group and an acid dissociation constant not smaller than 2.90 and not greater than 8.00, and a method for manufacturing the same are provided. The toner particles can have a volume average particle size not smaller than 0.01 μm and not greater than 100 μm and a coefficient of variation of volume distribution not lower than 1% and not higher than 100%. This liquid developer has excellent fixability which allows adaptation to various recording materials, can be fixed in a wide temperature range, and is extremely low in deterioration in fixability during storage.