Toner Particles with Crystalline Polyester Domains for Peeling Prevention

Solution Overview

Problem

Conventional toners face issues with peeling, especially in areas with high toner laid-on levels, and have poor storability, particularly in high-temperature, high-humidity environments, leading to image quality degradation over time.

Innovation Solution

A toner composition comprising toner particles with a binder resin, colorant, releasing agent, and crystalline polyester, where specific domains of the crystalline polyester and releasing agent are present in a ratio of at least 70% by number, with the crystalline polyester covering the releasing agent to enhance melting and release properties, thereby improving fixing performance and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional techniques are used to improve fixing performance, then fixing performance is improved, but peeling occurs in areas with high toner laid-on level

Engineering Contradiction:

Improvefixing performanceVSAvoidpeeling

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The toner particles are segmented into multiple functional domains: a releasing agent domain and a crystalline polyester domain. This segmentation allows the releasing agent to provide release properties while the crystalline polyester provides melt properties, preventing peeling in high toner laid-on level areas while maintaining fixing performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the toner particle are assigned different functions: the releasing agent domain (with diameter ≥1.0 μm) provides release properties, while the crystalline polyester domain (covering at least 80% of the releasing agent domain) provides melt properties. This local differentiation of properties prevents peeling while maintaining fixing performance.

Inventive Principle:

Principle #3Local quality

2Reliability

If toners with improved fixing performance are used, then fixing performance is improved, but storability deteriorates in high-temperature, high-humidity environments

Engineering Contradiction:

Improvefixing performanceVSAvoidstorability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The toner particles are segmented into multiple functional domains: a releasing agent domain and a crystalline polyester domain. This segmentation allows the releasing agent to provide release properties while the crystalline polyester provides melt properties, preventing peeling in high toner laid-on level areas while maintaining fixing performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the toner particle are assigned different functions: the releasing agent domain (with diameter ≥1.0 μm) provides release properties, while the crystalline polyester domain (covering at least 80% of the releasing agent domain) provides melt properties. This local differentiation of properties prevents peeling while maintaining fixing performance.

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 significantly reduces peeling and maintains image quality even after long-term storage, ensuring stable performance in varying environmental conditions.

Implementation Method 1

the crystalline polyester covering the releasing agent to enhance melting and release properties, thereby improving fixing performance

Methodology Applied

Scientific EffectMelting: Melting

Implementation Method 2

specific toner particles, each of which has domains of the crystalline polyester and domains of the releasing agent, are present at a ratio of at least 70% by number of the toner particles

Methodology Applied

Scientific EffectPhase separation:

Data Source

PatentUS10012923B2Toner

Publication Date: 2018.07.03 CANON KK

AI summary

Provided is a toner including toner particles, each of which contains a binder resin, a colorant, a releasing agent and a crystalline polyester, wherein in an observation of a cross-section each of the toner particles by transmission electron microscopy, specific toner particles each of which has domains of the crystalline polyester and domains of the releasing agent, are present at a ratio of at least 70% by number of the toner particles in the toner, an arithmetic mean of maximum diameters of the domains of the releasing agent is within prescribed range, and the specific toner particles satisfy prescribed conditions.