Core-Shell Toner with Polyvalent Metal Interface
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Solution Overview
Problem
Existing toners used in electrostatic latent image formation face challenges with low-temperature fixability and long-term developing performance, as they tend to undergo deformation and cracking due to repetitive stress, leading to shell exfoliation and image defects.
Innovation Solution
A toner composition featuring a core particle coated with a shell containing an amino resin and a polyvalent metal, where the polyvalent metal is present at the core-shell interface, enhancing adherence and suppressing shell exfoliation, with a surface storage elastic modulus between 6.50 GPa to 12.00 GPa to ensure durability and low-temperature fixability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If a binder resin with low melting point or glass transition temperature is used to achieve low-temperature fixability, then energy efficiency is improved, but toner-to-toner melt-bonding occurs during high-temperature storage
Solution Approach 1:
The toner is divided into a core particle and a shell layer. The core contains the binder resin with low melting point for low-temperature fixability, while the shell provides protection during storage, preventing melt-bonding between toner particles.
Solution Approach 2:
Different regions of the toner have different properties: the core has low melting point characteristics for energy efficiency, while the shell has higher stability characteristics for preventing storage issues. This local differentiation resolves the contradiction between low-temperature fixability and storage stability.
2Stability of the object's composition
If a thermosetting resin and thermoplastic resin are used in the shell layer to prevent melt-bonding, then storage stability is improved, but shell exfoliation occurs during repetitive printing
Solution Approach 1:
The shell is constructed as a composite material combining thermosetting resin and thermoplastic resin in specific proportions. This composite structure provides both storage stability and resistance to shell exfoliation during repetitive printing operations.
Solution Approach 2:
The invention specifies precise compositional parameters for the shell layer, including the ratio of thermosetting to thermoplastic resin and the presence of specific additives, to achieve optimal balance between storage stability and development durability.
3Reliability
If surface hardness is increased to prevent toner deformation, then durability is improved, but low-temperature fixability deteriorates
Solution Approach 1:
The toner structure is segmented into core and shell, allowing the core to maintain low hardness for low-temperature fixability while the shell provides the necessary durability and resistance to deformation during handling and printing.
Solution Approach 2:
Different hardness characteristics are assigned to different regions: the core maintains softness for easy fixation at low temperatures, while the shell provides harder, more durable surface properties that resist deformation and cracking during repetitive operations.
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 long-term developing performance by preventing shell exfoliation and maintaining low-temperature fixability, reducing image defects and toner deterioration, while ensuring high durability and resistance to deformation.
Implementation Method 1
a shell coating a surface of the core particle... the shell comprises an amino resin
Implementation Method 2
a polyvalent metal... the content P(M) of the polyvalent metal is 0.0010 to 2.0000 atomic %, the content P(M) being obtained by energy-dispersive x-ray analysis during an execution of a line scan in a range of 0.85d to 1.15d from an outline of the cross section of the toner particle toward a central part of the cross section
Implementation Method 3
a binder resin having a low melting point or glass transition temperature... enables an excellent low-temperature fixability
Implementation Method 4
the toner used to form a toner image by the development of the electrostatic latent image formed by a method such as electrophotography
Data Source
AI summary
A toner comprises a toner particle comprising a core particle comprising a resin component, a shell coating the surface of the core particle, and a polyvalent metal. The resin component comprises a polyester resin, and the shell comprises an amino resin; in an electron image of a cross section of the toner acquired using a transmission electron microscope, a polyvalent metal content P(M) obtained by energy-dispersive x-ray analysis at the core/shell interface and in the vicinity of this interface is 0.0010 to 2.00 atomic %; and the surface storage elastic modulus of the toner at a load of 30 μN at 25° C., according to nanoindentation measurement of the toner, is from 6.50 GPa to 12.00 GPa.