Toner External Additive Silica Particle Design for Embossed Paper Transfer
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Solution Overview
Problem
Existing electrostatically charged image developing toners face challenges in achieving high transfer characteristics on embossed paper, resulting in image defects due to the escape of external additives during continuous printing, especially at high coverage rates.
Innovation Solution
The use of silica particles A with a number average primary-particle diameter of 40 to 100 nm and average circularity of 0.50 to 0.90, surface-modified with silicone oil, and silica particles B with a diameter smaller than A, surface-modified with alkylalkoxysilane or silazane, to enhance transfer characteristics and reduce image defects by improving interaction between toner particles and preventing scattering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a toner with large diameter and high sphericity external additives is used to improve transfer characteristics, then transfer characteristics are improved, but adhesive force between toner particles is reduced causing particle scattering and rough images
Solution Approach 1:
The patent applies parameter changes by precisely controlling the diameter (40-100 nm) and circularity (0.50-0.90) of silica particles, and by selecting specific surface modifiers (silicone oil for particles A, alkylalkoxysilane or silazane for particles B). These parameter optimizations balance transfer characteristics with particle adhesion, preventing scattering while maintaining image quality.
Solution Approach 2:
The patent uses composite materials by combining two types of silica particles with different properties: particles A (larger diameter, surface-modified with silicone oil) and particles B (smaller diameter, surface-modified with alkylalkoxysilane or silazane). This composite approach allows simultaneous optimization of transfer characteristics and particle adhesion through synergistic effects.
2Ease of manufacture
If a large amount of external additive with large diameter and high sphericity is added to improve transfer characteristics, then transfer characteristics are improved, but partial escape of external additive occurs causing local abrasion of photoreceptor and image defects
Solution Approach 1:
The patent optimizes particle size parameters (40-100 nm for particles A, smaller than A for particles B) and surface modification parameters to control the behavior of external additives. These parameter changes prevent excessive particle escape during cleaning while maintaining transfer performance, thereby reducing image defects.
Solution Approach 2:
The patent uses surface modifiers (silicone oil, alkylalkoxysilane, silazane) as intermediary substances that mediate between the silica particles and the toner matrix. These intermediaries enhance particle attachment to the toner surface, preventing escape during the cleaning process and reducing harmful effects on the photoreceptor.
3Productivity
If conventional toners are used for continuous printing at high coverage rates, then productivity is maintained, but image defects increase due to escape of external additive
Solution Approach 1:
The patent optimizes the composition parameters of external additives (size distribution, surface modification type and amount) to ensure stable performance during continuous printing. These parameter changes maintain image quality consistency across high coverage rates while preserving productivity.
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 described toner formulation achieves high transfer characteristics on embossed paper, outputs images with high graininess, and minimizes image defects attributed to external additive escape, even after continuous printing at high coverage rates.
Implementation Method 1
silica particles A having a number average primary-particle diameter in the range of 40 to 100 nm and an average circularity in the range of 0.50 to 0.90, and are surface-modified with silicone oil, and silica particles B having a number average primary-particle diameter of 25 nm or more and smaller than the number average primary-particle diameter of the silica particles A, and are surface-modified with alkylalkoxysilane having a structure represented by Formula (1) or silazane
Implementation Method 2
electrostatically charged image developing toner including a particulate toner matrix containing an external additive on the surface of the particulate toner matrix
Data Source
AI summary
An electrostatically charged image developing toner includes a particulate toner matrix containing an external additive on the surface of the particulate toner matrix. The external additive includes silica particles A and silica particles B. The silica particles A have a number average primary-particle diameter in the range of 40 to 100 nm and an average circularity in the range of 0.50 to 0.90, and are surface-modified with silicone oil. The silica particles B have a number average primary-particle diameter of 25 nm or more and smaller than the number average primary-particle diameter of the silica particles A, and are surface-modified with alkylalkoxysilane having a specific structure or silazane.