Toner Core-Shell Structure for Fixing Strength and Chargeability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current toner technologies face challenges in achieving low-temperature fixability and heat-resistant storage stability while preventing image fog and photoconductor filming, as crystalline polyester resins enhance fixability but compromise chargeability and fluidity, and shell layers improve stability but reduce additive stability.
Innovation Solution
A toner with colored particles having a core and shell layer, where the shell layer is 30-130 nm thick and contains a resin with a metal oxide and silicon compound, with a specific electronegativity ratio and adhesion rate, ensuring balanced chargeability and fluidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a crystalline polyester resin is used as a sub-binder to achieve low-temperature fixability, then fixing strength is improved, but chargeability and fluidity deteriorate
Solution Approach 1:
The invention divides the toner into a core region and a surface region with different compositions. The core contains the crystalline polyester resin for low-temperature fixability, while the surface region contains amorphous polyester resin and specific external additives to maintain chargeability and fluidity, thus resolving the contradiction between fixing strength and operational ease.
Solution Approach 2:
Different regions of the toner are given different properties: the core has high crystallinity for fixing strength, while the surface has amorphous structure with controlled electronegativity for chargeability. This local differentiation allows simultaneous achievement of fixing strength and operational ease.
2Reliability
If a shell layer is added to prevent filming and improve storability, then heat-resistant storage stability is improved, but additive stability deteriorates
Solution Approach 1:
The shell layer acts as an intermediary between the core and the external environment. It provides heat-resistant storage stability while the specific electronegativity ratio of external additives on the surface maintains additive stability, thus resolving the contradiction between reliability and compositional stability.
3Reliability
If the shell layer thickness is increased to improve storage stability, then heat-resistant storage stability is improved, but low-temperature fixability deteriorates
Solution Approach 1:
The invention optimizes the shell layer thickness parameter to a specific range (30-130 nm) and controls the electronegativity ratio of external additives. This parameter optimization allows simultaneous achievement of heat-resistant storage stability and low-temperature fixability, resolving the contradiction between reliability and fixing strength.
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 achieves excellent low-temperature fixability and heat-resistant storage stability without causing image fog or photoconductor filming, maintaining chargeability and fluidity through controlled shell layer thickness and electronegativity ratio.
Implementation Method 1
FIG. 1 is a graph showing a relation between the amount of charge of metal oxides in contact charging with iron powder
Implementation Method 2
A proportion of an amount of the metal oxide directly adhered to the surfaces of the colored particles to a total amount of the metal oxide present on the colored particles is from 60% to 90% by mass
Data Source
AI summary
A toner is provided. The toner comprises colored particles and external additives present on surfaces of the colored particles. The colored particles each comprise a core and a shell layer. The core contains a crystalline resin, a non-crystalline resin, and a colorant. The shell layer contains a resin and has a thickness of from 30 to 130 nm. The external additives comprise a metal oxide and a silicon compound. An electronegativity X(A) of the metal oxide and an electronegativity X(Si) of the silicon compound satisfy a relation 0.5≤X(A)/X(Si)≤0.8. A proportion of an amount of the metal oxide directly adhered to the surfaces of the colored particles to a total amount of the metal oxide present on the colored particles is from 60% to 90% by mass.