Two-Component Developer Silica Carrier Charge Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Two-component developers using crystalline resin and titanium oxide carriers experience a decrease in charge amount over time, leading to image quality deterioration due to low charge holding abilities, resulting in unstable image output.
Innovation Solution
Incorporating silica particles with a number average particle diameter of 10 to 30 nm on the carrier surface in a specific concentration range to prevent charge recombination and maintain charge stability, combined with a toner containing amorphous and crystalline resins for improved low-temperature fixability and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a two-component developer uses a toner containing crystalline resin and a carrier pre-treated with titanium oxide, then low-temperature fixability is improved, but charge amount decreases after long-term storage
Solution Approach 1:
The invention changes the material parameter of the carrier surface treatment from titanium oxide to silica particles, and adjusts the particle size parameter to 10 to 30 nm with a specific concentration range (5 at % ≤ S1 ≤ 10 at %). This parameter change maintains low-temperature fixability while significantly improving charge holding ability after long-term storage, resolving the contradiction between fixation temperature and charge holding reliability.
Solution Approach 2:
The invention creates a composite carrier surface structure by attaching silica particles to the carrier base material. This composite structure combines the low-temperature fixability properties with enhanced charge holding ability, as the silica particles prevent charge recombination while maintaining the overall composite material performance for both fixation and charge stability.
2Reliability
If silica particles with 10 to 30 nm diameter are attached to carrier surface in specific concentration, then charge stability is maintained, but manufacturing complexity increases
Solution Approach 1:
The invention specifies precise parameters for silica particle attachment: particle diameter of 10 to 30 nm and surface concentration of 5 at % ≤ S1 ≤ 10 at %. These parameter specifications ensure charge stability while providing clear manufacturing guidelines that balance complexity with performance requirements.
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 ensures stable high-quality image output over a long period by maintaining charge levels and preventing charge recombination, enhancing the developer's long-term storage properties and image forming capabilities.
Implementation Method 1
a charge amount is decreased after long-term storage, which caused a problem of image quality deterioration at an initial stage of use. The reason therefor may be that a charge holding ability of the crystalline resin is low and a charge holding ability of titanium oxide is low.
Implementation Method 2
by using an appropriate amount of silica particles having higher resistance than that of titanium oxide in the carrier pre-treatment to prevent recombination of charges on a toner side and a carrier side
Implementation Method 3
Low-temperature fixability of the toner has been realized by a technology of introducing a crystalline resin into a non-crystalline resin (also referred to as an amorphous resin) to impart a sharp-melting property to a binder resin
Data Source
AI summary
The present invention provides a two-component developer for developing an electrostatic charge image, which includes a toner and a carrier, wherein the toner contains an amorphous resin and a crystalline resin as binder resins and an inorganic particle as external additive particle, and the carrier has a surface to which silica particles having a number average particle diameter of 10 to 30 nm are attached in an amount in the range of the following Equation (1): 5 at %≤S1≤10 at %, wherein S1 represents a concentration of Si element as measured by XPS and indicates an amount of silica on the surface of the carrier.