Toner with Titanium Catalyst Polyester Resin for Offset Resistance
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Solution Overview
Problem
Conventional toners for full-color image formation in electrophotography face challenges with high-temperature offset resistance, color reproducibility, and transparency, particularly due to the low self-cohesion of binder resins and differences in refractive index between mold releasing agents and OHP sheet materials.
Innovation Solution
A toner comprising a binder resin synthesized with an aromatic carboxylic acid titanium compound, inorganic fine particles such as titanium oxide, and a wax, which improves dispersibility and charge stability, enhancing fixing properties and color mixability while maintaining transparency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a sharp melting resin is used to improve color reproducibility and transparency, then color mixing and transparency are improved, but high-temperature offset resistance deteriorates due to low self-cohesion of the binder resin
Solution Approach 1:
The patent uses a composite binder resin system combining polyester resin with polycarboxylic acid and polyol, creating a material that exhibits both sharp melting properties (for color reproducibility) and high self-cohesion (for offset resistance). This composite approach allows the resin to display multiple beneficial properties that cannot be achieved with a single resin type.
Solution Approach 2:
The patent modifies the chemical composition parameters of the binder resin by incorporating specific ratios of polycarboxylic acid (0.1-10 wt%) and polyol (0.1-10 wt%) to achieve optimal balance between melting sharpness and cohesive strength. By adjusting these compositional parameters, the resin maintains both transparency and offset resistance.
2Reliability
If high-crystallinity waxes are used as mold releasing agents to improve high-temperature offset resistance, then offset resistance is improved, but transparency and chroma of projected images deteriorate due to refractive index differences
Solution Approach 1:
The patent changes the crystallinity parameter of the wax from high to low (using waxes with melting points of 50-100°C and low crystallinity structures). This parameter change reduces the refractive index difference between the wax and OHP sheet material, thereby improving transparency while maintaining sufficient offset resistance through the low-melting-point characteristic.
Solution Approach 2:
The patent applies low-crystallinity wax specifically as the mold releasing agent component, allowing different parts of the toner composition to have different functional properties. The low-crystallinity wax provides transparency and release properties, while the polyester binder resin provides the necessary cohesion and melting sharpness.
3Ease of manufacture
If polyester resin with conventional catalysts is used, then manufacturing is straightforward, but fixing property and color reproducibility are insufficient
Solution Approach 1:
The patent changes the chemical composition parameters of the polyester resin by incorporating specific amounts of polycarboxylic acid (0.1-10 wt%) and polyol (0.1-10 wt%) to achieve optimal fixing properties. This compositional modification improves low-temperature fixing capability and color reproducibility while maintaining conventional manufacturing processes.
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 high-temperature offset resistance, improved color reproducibility, and transparency, ensuring high image quality and efficient transfer processes.
Implementation Method 1
a resin having polyester units which is synthesized by use of an aromatic carboxylic acid titanium compound as a catalyst
Implementation Method 2
the toner contains inorganic fine particles
Implementation Method 3
When a sharp melting resin is used, a problem with high-temperature offset resistance usually tends to occur at the time of melting of the toner in the heat-pressure fixing step
Data Source
AI summary
The present invention provides a toner improved in dispersibility of a colorant in the toner particles and excellent in the color reproducibility including color mixability and transparency. The toner is also excellent in the stability in long-term of the chargeability and capable of forming images maintaining high image quality. The present invention provides a toner for forming a full-color image which includes at least toner particles containing a binder resin, a colorant and a wax, and inorganic fine particles, wherein the binder resin comprises a resin having polyester units which is synthesized by use of an aromatic carboxylic acid titanium compound as a catalyst, and the inorganic fine particles comprise fine titanium oxide particles.