Toner Resin Composition for Low-Temperature Fixing
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Solution Overview
Problem
Conventional toner manufacturing methods, such as the kneading pulverization method, fail to achieve a high level of low-temperature fixing property, high temperature-resistant offset property, and heat-resistant storage stability due to issues like non-uniform particle size, broad particle diameter distribution, and adhesion problems.
Innovation Solution
A toner comprising a non-crystalline polyester resin and a modified crystalline polyester resin with a urethane or urea skeleton, which exhibits a glass transition temperature difference of 10°C or greater, ensuring rapid viscosity decrease near the fixing temperature for improved compatibility and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a kneading pulverization method is used to manufacture toner, then the manufacturing process is simple, but the particle diameter is large, the shape is non-uniform, and the particle diameter distribution is broad
Solution Approach 1:
The patent replaces the mechanical kneading pulverization method with a polymerization method. This substitution allows for precise control of particle diameter through chemical synthesis rather than mechanical grinding, resulting in uniform spherical particles with narrow size distribution while maintaining manufacturing feasibility through established polymerization processes
Solution Approach 2:
The patent changes the fundamental manufacturing approach from mechanical processing to chemical synthesis. By controlling polymerization parameters such as monomer ratios, reaction conditions, and catalysts, the particle diameter and shape can be precisely controlled to achieve uniform spherical particles with narrow size distribution
2Reliability
If a wax (releasing agent) is added to improve fixability, then the releasing effect is enhanced, but the toner cracks at the wax interface during pulverization and adhesion to carrier and photoconductor occurs
Solution Approach 1:
The patent extracts the releasing agent from the toner particle surface, eliminating the harmful interface between wax and toner. By using polymerization method, the releasing agent is completely removed from the particle surface, preventing cracking during pulverization and adhesion to carrier and photoconductor while maintaining fixability through alternative mechanisms
Solution Approach 2:
The patent converts the potential harm of wax addition into benefit by using polymerization method to create uniform particles that inherently resist adhesion. The polymerization process creates a stable particle structure that prevents cracking and adhesion issues while maintaining the desired releasing effect through controlled surface properties
3Manufacturing precision
If conventional polymerization method is used, then particle diameter is reduced and shape is uniform, but the low-temperature fixing property is insufficient
Solution Approach 1:
The patent uses a composite resin system comprising polyester resin and polyurethane resin in specific ratios. This composite material approach combines the advantages of both resins to achieve uniform particle shape and diameter while providing superior low-temperature fixing property through the synergistic effects of the resin combination
Solution Approach 2:
The patent optimizes the resin composition parameters by controlling the ratio of polyester resin to polyurethane resin within specific ranges. This parameter optimization enables the toner to achieve both uniform particle morphology and enhanced low-temperature fixing property through controlled material composition
4Reliability
If crystalline polyester resin is used to achieve rapid melting, then low-temperature fixing is improved, but the non-crystalline polyester resin does not melt sufficiently and fixing does not occur until both resins melt
Solution Approach 1:
The patent changes the melting behavior parameters by selecting crystalline polyester resin with specific melting point characteristics. The crystalline polyester resin is chosen to melt at a lower temperature than the non-crystalline polyester resin, creating a temperature gradient that enables sequential melting and sufficient fixing at relatively low temperatures
Solution Approach 2:
The patent uses a composite resin system where crystalline polyester resin provides rapid melting at lower temperatures while non-crystalline polyester resin provides stability. The specific ratio and combination of these two resin types ensures that the crystalline component melts first to enable fixing, while the non-crystalline component maintains structural integrity
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 superior low-temperature fixing property, high temperature-resistant offset property, and heat-resistant storage stability by enhancing the crystallinity and compatibility of the resin components, preventing filming and agglomeration, and maintaining image quality in high-temperature and high-humidity environments.
Implementation Method 1
a crystalline polyester resin rapidly melts compared to a non-crystalline polyester resin
Implementation Method 2
a sea-island phase separation structure due to the resin and a wax mutually incompatible
Data Source
AI summary
To provide a toner, including at least: a non-crystalline polyester resin; and a crystalline polyester resin, wherein the toner has a glass transition temperature in a first heating Tg1st and a glass transition temperature in a second heating Tg2nd, and a difference between Tg1st and Tg2nd (Tg1st-Tg2nd) is 10° C. or greater, and wherein the crystalline polyester resin is a modified crystalline polyester resin having a urethane skeleton or a urea skeleton, or both thereof.