Modified Polyester Toner Resin Low-Temperature Fixing
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Solution Overview
Problem
Current toner technologies face challenges in achieving both excellent low-temperature fixing properties and offset resistance while maintaining high image quality, particularly in electrophotographic processes, where existing resins fail to optimize molecular structure and weight for efficient heat control and particle dispersion.
Innovation Solution
A toner composition using a modified polyester binder resin with an isocyanate-derived functional group, synthesized using a non-Sn catalyst like titanium or bismuth, which allows for controlled molecular weight and gel formation prevention, enabling uniform dispersion and improved heat management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a polyester resin is used to achieve low-temperature fixing property, then the fixing temperature is lowered, but the heat resistant preservability deteriorates
Solution Approach 1:
The patent optimizes the molecular weight of the polyester resin within a specific range (10,000-100,000) and controls the glass transition temperature (Tg) to balance low-temperature fixing capability with heat resistant preservability. By precisely adjusting these molecular parameters, the resin achieves adequate low-temperature fixing property while preventing excessive softening at higher temperatures.
Solution Approach 2:
The patent creates a composite binder system by combining polyester resin with other resins or additives to form a multi-component binder. This composite structure allows the polyester to provide low-temperature fixing while the other components contribute heat resistance, thereby resolving the contradiction between the two opposing requirements.
2Temperature
If the molecular weight of polyester resin is reduced to lower F1/2 temperature, then the low-temperature fixing property is improved, but the hot-offset generation temperature is lowered
Solution Approach 1:
The patent establishes a specific molecular weight range (10,000-100,000) for the polyester resin to optimize the F1/2 temperature. By controlling the molecular weight within this range rather than simply minimizing it, the patent achieves adequate low-temperature fixing while preventing excessive reduction that would lower the hot-offset generation temperature and cause offset problems.
3Ease of manufacture
If a grinding method is used to manufacture toner, then the toner can be produced economically, but the particle diameter distribution becomes wide and fine particles must be eliminated
Solution Approach 1:
The patent replaces the mechanical grinding process with a chemical polymerization method to manufacture toner particles. This substitution eliminates the need for mechanical size reduction and subsequent classification, directly producing particles with a narrow diameter distribution (span ≤ 1.5) while maintaining economic viability through efficient chemical synthesis processes.
4Ease of manufacture
If the grinding method is used to manufacture toner, then production is economically viable, but the uniform dispersion of colorant and charge controlling agent is difficult
Solution Approach 1:
The patent replaces mechanical mixing and grinding with in-situ polymerization, where the colorant and charge controlling agent are incorporated into the polymer matrix during the polymerization process itself. This chemical approach ensures uniform molecular-level dispersion of all components throughout the toner particles, eliminating the aggregation and non-uniformity problems associated with mechanical mixing.
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 solution provides both excellent low-temperature fixing properties and offset resistance, enabling the formation of high-quality images with controlled particle size and distribution, addressing the limitations of previous toner technologies.
Implementation Method 1
enabling uniform dispersion and improved heat management
Implementation Method 2
improved heat management
Data Source
AI summary
A toner containing a colorant, and a binder resin, wherein the toner is prepared by dissolving or dispersing a colorant, a precursor of the binder resin having a site capable of reacting with an active hydrogen group-containing compound, the active hydrogen group-containing compound, in an organic solvent, to prepare a toner constituent mixture liquid, dispersing or emulsifying the toner constituent mixture liquid, in an aqueous medium while subjecting the precursor to a reaction with the active hydrogen group-containing compound, to prepare a toner dispersion, and removing the organic solvent from the toner dispersion; the binder resin contains a modified polyester having an isocyanate-derived binding site; the Sn content in the toner is 800 ppm or less; the content of a metal which is non Sn and derived from a polyesterified catalyst is 10 ppm to 200 ppm; and the content of a metal which is non Sn and derived from an isocyanated catalyst is 10 ppm to 200 ppm.