Toner Set with Layered Silicate for Charging Stability

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Solution Overview

Problem

The existing techniques for reducing toner diameter to minimize waste and improve image quality lead to increased slipping and charging instability, particularly in color toner systems, resulting in uneven charge distribution and deteriorated color reproducibility over time.

Innovation Solution

A toner set comprising yellow, magenta, cyan, and black toners, each containing a binder resin, coloring agent, release agent, and layered silicate compound, with specific volume average particle diameters and aluminum content ratios to maintain consistent charge levels and improve charging stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the diameter of the toner is reduced, then the amount of toner used is reduced and image quality is improved, but the charging stability deteriorates and cases of slipping through cleaning means increase

Engineering Contradiction:
Improvetoner use amountVSAvoidcharging stability
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the toner by incorporating specific inorganic compounds (silicon oxide, aluminum oxide, titanium oxide) with controlled particle size ratios. This compositional parameter change allows the toner to maintain stable charging properties even at reduced diameters of 3 μm to 5 μm, resolving the contradiction between reduced toner usage and maintained charging stability.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the diameter of the toner is reduced, then image defects are suppressed and thin line reproducibility is improved, but the number of cases of slipping through cleaning means is increased

Engineering Contradiction:
Improveimage qualityVSAvoidslipping through cleaning means
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent creates a composite toner material combining organic binder resin with inorganic compounds (silicon oxide, aluminum oxide, titanium oxide) in specific ratios. This composite structure provides both the smooth surface needed for high-quality image reproduction and the adhesive properties needed to prevent slipping through cleaning means, even at reduced particle diameters.

Inventive Principle:
Principle #40Composite materials

3Reliability

If heterogeneous toner is used to improve cleaning performance, then adhesive force between toner and cleaning member is increased, but fluidity of the toner is lowered

Engineering Contradiction:
Improvecleaning performanceVSAvoidtoner fluidity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by creating toner particles with heterogeneous internal structure where inorganic compounds are distributed within the binder resin. This internal heterogeneity provides cleaning performance and adhesive force, while the overall particle remains sufficiently fluid for development. The key is controlling the particle size ratio of inorganic compounds to be 0.3 μm to 1.0 μm, which provides local adhesive sites without compromising overall fluidity.

Inventive Principle:
Principle #3Local quality

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 solution effectively reduces charge differences between toner colors, enhancing long-term charging stability and color reproducibility by controlling the aluminum content in each toner, thereby stabilizing developability and transferability.

Implementation Method 1

the layered inorganic compound can exist in the vicinity of the surface layer of the toner, a binder resin in the vicinity of the toner surface layer thickens, it is possible to make the toner heterogeneous appropriately

Methodology Applied
Scientific EffectHeterogeneous structure formation:

Implementation Method 2

a toner image forming step of forming a toner image by developing the color toner on an electrostatic latent image formed by charging and exposing a surface of an electrostatic latent image bearing member

Methodology Applied
Scientific EffectTriboelectric charging: Triboelectric Effect

Data Source

PatentUS10539897B2Image forming method and toner set for developing electrostatic latent image
Publication Date: 2020.01.21 KONICA MINOLTA INC

AI summary

An image forming method uses a color toner including a yellow toner, a magenta toner, a cyan toner, and a black toner. The image forming method includes a toner image forming step of forming a toner image by developing the color toner on an electrostatic latent image formed by charging and exposing a surface of an electrostatic latent image bearing member, a transfer step of transferring the toner image onto a recording medium to form a color toner image, and a fixing step of fixing the color toner image on the recording medium. Each toner contain at least a binder resin, a coloring agent, a release agent, and a layered silicate compound. The volume average particle diameter of each toner is 4 to 6 μm. The content of the aluminum element in each toner represented by the Net intensity by WDXRF analysis has a specific relationship.