Core-Shell Toner Additive with Silane Coupling for Adhesion
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Solution Overview
Problem
Existing complex particles for electrophotography toners face challenges in maintaining flowability and charge control due to low adhesion strength of shell particles on core particles, leading to detachment under stress and instability in charge levels.
Innovation Solution
A complex particle design featuring a core-shell structure with specific diameter ratios and a silane coupling agent to enhance adhesion, where the core particle is made of organic or inorganic material and the shell particle of the other material, with a method involving acid treatment and heating to form a particle adhesion body and subsequent silane coupling to fix the shell particles on the core.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If shell particles are coated on core particles to form complex particles, then various characteristics are provided, but adhesion strength is insufficient and shell particles detach under stress
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle diameter ratios between shell and core particles, and by adjusting the concentration and type of silane coupling agents. This optimization of parameters ensures strong adhesion while maintaining charge stability.
Solution Approach 2:
The patent uses composite materials by combining organic and inorganic materials in specific ratios within the complex particle structure. This composite approach provides both the desired characteristics and improved adhesion strength through material synergism.
2Ease of operation
If complex particles are used as external additive for toner, then flowability and charge control are improved, but shell particles detach under stress leading to instability
Solution Approach 1:
The patent optimizes parameters including the diameter ratio between shell and core particles, the concentration of silane coupling agents, and the composition ratios of organic and inorganic materials. These parameter adjustments ensure that complex particles maintain both flowability and charge stability without shell detachment.
3Strength
If shell particles are attached to core particles, then complex particle structure is formed, but adhesion is weak causing detachment under stress
Solution Approach 1:
The patent introduces silane coupling agents as intermediary substances that chemically bond to both organic and inorganic materials. This intermediary approach significantly strengthens adhesion between shell and core particles while the method remains practically feasible.
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 complex particle exhibits high adhesion strength, maintaining charge levels and flowability even under stress, ensuring stable performance as an external additive for toners by preventing shell particle detachment and ensuring consistent charge distribution.
Implementation Method 1
adding a silane coupling agent to the heated dispersion liquid to prepare the complex particle
Implementation Method 2
adding an acid to the dispersion liquid until the dispersion liquid reaches an isoelectric point of an inorganic material of the inorganic core particle
Implementation Method 3
heating the dispersion liquid to form a particle adhesion body comprising the inorganic particle on the organic particle
Data Source
AI summary
A complex particle including a core particle and a shell particle,wherein the shell particle is disposed on the core particle,wherein the core particle includes an organic material or an inorganic material as a primary component and the shell particle includes the other of the organic material and the inorganic material as a primary component,whereinan average particle diameter of the core particle is greater than or equal to about 80 nanometers and less than or equal to about 300 nanometers,a coefficient of variation of an average particle diameter of the core particle is greater than or equal to about 2% and less than or equal to about 10%,an average particle diameter of the shell particle is greater than or equal to about 5 nanometers and less than or equal to about 30 nm,a ratio of the average particle diameter of the shell particle relative to the average particle diameter of the core particle is greater than or equal to about 0.016 and less than or equal to about 0.25,an average particle diameter of the complex particle is greater than or equal to about 90 nanometers and less than or equal to about 350 nanometers,a ratio of multipliers a volume resistance and a sheet resistance of the complex particle is greater than or equal to about 0.7 and less than or equal to about 1.4, wherein the ratio of multipliers is a ratio of β1/β2, wherein β1 is an exponent in an expression of the volume resistance according to the formula ρv=α1·10β1 and wherein β2 is an exponent in an expression of the sheet resistance according to the formula ρs=α2·10β2 andwherein a change of a number of shell particles present on the core particle before and after ultrasonic irradiation of a dispersion liquid of the complex particle including about 1 weight percent of the complex particle dispersed in water is greater than or equal to about 0.5% and less than or equal to about 5%ρvρs.