Barium Compound Toner for UV Stability
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Solution Overview
Problem
Electrophotography technologies face issues with image cracking and decreased gloss due to long-term storage and exposure to ultraviolet radiation, particularly in graphic art and food packaging applications, where conventional toners with aluminum or titania particles are prone to embrittlement and discoloration.
Innovation Solution
A toner formulation incorporating a barium compound with specific viscoelastic properties and an ultraviolet absorbent, which disperses uniformly and absorbs UV radiation to prevent cracking and discoloration, while maintaining image gloss and quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional toners with aluminum or titania particles are used, then image quality is maintained initially, but image cracking and discoloration occur under long-term UV exposure
Solution Approach 1:
The patent changes the particle material parameter from aluminum/titania to barium compound, and optimizes the particle size distribution parameters (D10, D50, D90) to achieve both UV resistance and image quality. This material substitution fundamentally alters the toner's interaction with UV radiation, preventing the harmful effects while maintaining image stability.
Solution Approach 2:
The patent creates a composite toner formulation combining barium compound particles with binder resin and colorant. This composite structure integrates the UV-blocking properties of barium compound with the functional requirements of electrophotographic toner, achieving both protection against UV degradation and proper image formation characteristics.
2Reliability
If ultraviolet absorbent compounds are incorporated into toner, then UV radiation effects are suppressed, but toner composition complexity increases
Solution Approach 1:
The barium compound particles serve multiple functions simultaneously: they act as UV blockers, maintain proper toner flow characteristics, contribute to image gloss, and provide structural stability during fixing. This multi-functionality reduces the need for separate additives, simplifying the overall composition while achieving UV protection.
Solution Approach 2:
The patent optimizes the concentration parameter of barium compound (0.1-0.5% by mass) to achieve effective UV protection without excessive addition. This precise parameter control ensures sufficient UV absorption while maintaining simple toner formulation and proper processing characteristics.
3Strength
If barium compound with specific viscoelasticity is used, then image cracking is prevented, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies the relaxation modulus parameter G(t) at a particular time point (t=10×Dt) to characterize the viscoelastic properties of barium compound particles. By controlling this single critical parameter within a specific range, the patent achieves crack prevention without requiring control of multiple complex parameters, simplifying the manufacturing precision requirements.
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 effectively prevents image cracking and discoloration under long-term UV exposure, ensuring stable image quality and gloss levels, even on materials sensitive to sunlight, by using a barium compound to stabilize the binder resin and an ultraviolet absorbent to neutralize UV-induced degradation.
Implementation Method 1
incorporating in advance a compound having an ultraviolet absorbing function into a toner together with other raw materials. Such a method is intended to suppress the effect of ultraviolet radiation on other materials in the toner, by making the compound having an ultraviolet absorbing function to absorb ultraviolet radiation, and converting the absorbed light energy into vibration energy in the molecules.
Implementation Method 2
the toner having a relaxation modulus G(t) of from 2.0×102 Pa to 3.0×103 Pa in a relaxation time of t=10×Dt (wherein Dt is the heating time taken during fixing) as determined by the measurement of dynamic viscoelasticity
Data Source
AI summary
There is provided a toner for electrophotography containing at least a binder resin, a colorant and a barium compound, and having a relaxation modulus G(t) of from about 2.0×102 Pa to about 3.0×103 Pa in a relaxation time of t=10×Dt (wherein Dt is the heating time taken during fixing) as determined by the measurement of dynamic viscoelasticity, and a barium content of from about 0.1% to about 0.5% with respect to the total amount of constituent atoms in the toner as determined by X-ray fluorescence.