Toner Silica Surface Modification for Transfer Stability

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Solution Overview

Problem

Existing toner technologies face challenges in maintaining transferability and image quality, especially with materials having large surface irregularities, leading to reduced dot reproducibility and increased contamination risks during high-speed printing.

Innovation Solution

A toner with toner particles containing a binder resin and wax, and silica fine particles on their surfaces, where the silica particles have a specific diameter range and coverage rate, and a controlled uniaxial collapse stress, enhancing adhesive forces between toner particles while reducing adhesion to the transfer member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple transfer operations are used to transfer toner image from image bearing member to intermediate transfer member and then to transfer material, then full-color image forming capability is achieved, but dot reproducibility deteriorates and transfer efficiency decreases

Engineering Contradiction:
Improvefull-color image forming capabilityVSAvoiddot reproducibility
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The invention applies local quality by creating toner particles with non-uniform surface properties - specifically, a core-shell structure where the surface layer has different characteristics from the core. The surface is modified with silane coupling agents and inorganic fine particles to create localized regions with enhanced transfer properties, allowing the toner to maintain both good transfer efficiency and dot reproducibility in the multi-transfer process

Inventive Principle:
Principle #3Local quality

2Productivity

If high-speed printing is performed, then productivity increases, but remaining toner passes through the regulating member and accumulates on the intermediate transfer member causing contamination

Engineering Contradiction:
Improveprinting speedVSAvoidmember contamination
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention converts the potential harm of remaining toner into a benefit by designing toner particles that deliberately control their adhesion properties. The surface-modified toner particles have reduced adhesion to the intermediate transfer member surface, allowing them to be easily removed by the regulating member even at high printing speeds. This prevents toner accumulation and contamination while maintaining high productivity

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Manufacturing precision

If external additives are added to enhance transferability, then transfer efficiency improves, but adhesive force between toners decreases causing voids in transferred images

Engineering Contradiction:
Improvetransfer efficiencyVSAvoidadhesive force between toners
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The invention applies parameter changes by carefully controlling the surface properties of toner particles through silane coupling agent treatment and inorganic fine particle addition. The surface modification parameters are optimized to achieve the right balance: sufficient adhesion to the intermediate transfer member for complete transfer, but not so much that toner particles stick together forming voids. The inorganic fine particles (5-50 nm) provide controlled surface energy that prevents both transfer failures and toner aggregation

Inventive Principle:
Principle #35Parameter changes

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 ensures stable image output and reduced member contamination across varying environments and printing speeds, with improved cleanability and transfer efficiency.

Implementation Method 1

studies have been recently made in which various fine particles are externally added to a surface of the toner as one procedure for enhancing transferability and contamination resistance of a transfer member

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

it is usually necessary to transfer a toner image visualized, from an image bearing member to the intermediate transfer member

Methodology Applied
Scientific EffectElectrostatic transfer: Electrostatics

Implementation Method 3

a mechanism for scraping a toner remaining on the intermediate transfer member by a regulating member such as a blade for the purpose of cleaning

Methodology Applied
Scientific EffectMechanical scraping: Mechanical Force

Data Source

PatentEP2799929B1Toner and image forming method
Publication Date: 2016.06.08 CANON KK
  • EP2799929B1 patent drawingFigure 1
  • EP2799929B1 patent drawingFigure 2~3
  • EP2799929B1 patent drawing

AI summary

Provided is a toner that allows a transferred image to be stably output regardless of smoothness of a transfer material even under high-temperature and high-humidity environment or under low-temperature and low-humidity environment, that is excellent in cleanability for a transfer member even at the time of high-speed printing, and that causes less member contamination. The toner is a toner including toner particles each containing a binder resin and a wax, and silica fine particles on surfaces of the toner particles, wherein the silica fine particles have a number-average particle diameter of primary particles of 60nm or more and 300nm or less, a coverage rate of the surfaces of the toner particles with the silica fine particles is 15% or more and 95% or less, and the toner has a uniaxial collapse stress at a maximum consolidation stress of 10.0 kPa, of 2.5 kPa or more and 3.5 kPa or less.