MgxMnFeO4 Carrier Core Material for Electrophotographic Developer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional two-component electrophotographic developers face issues with carrier scattering and image quality due to low magnetic susceptibility particles, which cannot be effectively prevented by existing methods, and result in abnormal image transfer and reduced toner image quality.

Innovation Solution

A carrier core material with a specific composition of Mg x Mn (1-x) Fe y O 4, where 0 < x < 1 and 1.6 ≤ y ≤ 2.4, is developed, with a half-value width of the XRD peak ≤ 0.180°, and magnetic susceptibility between 15 A.m2/kg and 65 A.m2/kg, to reduce low magnetic susceptibility particles and prevent carrier scattering, while maintaining image quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the particle size of the carrier is reduced to increase specific surface area, then the electric charging capability of the toner particle is improved, but the carrier easily allows abnormal phenomena such as adhesion and scattering to occur

Engineering Contradiction:

Improveelectric charging capabilityVSAvoidcarrier scattering and adhesion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the magnetic susceptibility parameter of the carrier from a conventional range to a specific range of 15-65 A.m²/kg. This parameter change allows the carrier to maintain adequate magnetic force for preventing scattering while reducing excessive magnetic attraction that causes adhesion to the photoreceptor, thus resolving the contradiction between charging capability and scattering/adhesion prevention

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite carrier structure with a core material having specific magnetic properties (magnetic susceptibility 15-65 A.m²/kg) combined with a resin coating. This composite structure allows the core to provide necessary magnetic force while the resin layer prevents direct contact and adhesion, resolving the contradiction between maintaining magnetic brush stability and preventing carrier adhesion

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If the content of carrier with particle size smaller than 22μm is reduced to prevent carrier scattering, then carrier adhesion to photoreceptor is reduced, but high image quality and full colorization cannot be achieved

Engineering Contradiction:

Improvecarrier adhesionVSAvoidimage quality

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention changes the magnetic susceptibility parameter of carriers across all particle sizes to 15-65 A.m²/kg, which fundamentally alters the carrier behavior in the magnetic field. This allows smaller carriers (<22μm) to be used without causing adhesion, as the controlled magnetic susceptibility prevents excessive magnetic attraction to the photoreceptor while maintaining adequate magnetic brush stability for high image quality

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 solution significantly reduces carrier scattering and enhances image quality by stabilizing the magnetic brush, allowing for high-quality full colorization in electrophotographic developers used in copiers and printers.

Implementation Method 1

a carrier for electrophotographic developer... with a magnetic susceptibility between 15 A.m2/kg and 65 A.m2/kg... the carrier with low magnetic susceptibility that exists in the carrier causes the carrier scattering to occur

Methodology Applied

Scientific EffectMagnetic susceptibility: Magnetism

Implementation Method 2

the carrier is prevented from scattering by an existence of a magnetic force and an electrostatic force to let the carrier hold on the development sleeve against a centrifugal force, added to the carrier by rotation of the development sleeve

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

the carrier is prevented from scattering by an existence of a magnetic force and an electrostatic force to let the carrier hold on the development sleeve against a centrifugal force

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Data Source

PatentEP2136253B1Carrier core material for electrophotographic developing agent, process for producing the carrier core material, carrier for electrophotographic developing agent, and electrophotographic developing agent

Publication Date: 2015.11.18 DOWA ELECTRONICS MATERIALS CO LTD

Figure 1~2
Figure 3

AI summary

To provide a carrier for electrophotographic developer, capable of realizing a high image quality and full colorization and reducing carrier scattering, and a manufacturing method of the same, and an electrophotographic developer containing the carrier. A carrier core material for electrophotographic developer, with a general formula expressed by MgxMn(1-x)FeyO4 (where 0 < x < 1, and 1.6 ≤ y ≤ 2.4), wherein a half-value width B of a peak having a maximum intensity in a powder XRD pattern satisfies B ≤ 0.180 (degree), is manufactured and from this carrier core material for electrophotographic developer, the carrier for electrophotogrphic developer and the electrophotographic developer are manufactured.