Toner Formulation for Low-Temperature Fixing and Offset Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electrophotographic image forming technologies face challenges in achieving high-quality image formation with low-temperature fixing, offset resistance, storage stability, charge rising property, and pulverizability, particularly in high-speed and energy-efficient printers, copiers, and facsimiles, where existing toners often suffer from poor mechanical strength, charge stability, and environmental safety concerns.
Innovation Solution
A toner formulation containing a binder resin with specific polyester resins and an aromatic oxycarboxylic acid metal compound, where the polyester resins have distinct softening points and include 1,2-propane diol, enhancing low-temperature fixing, offset resistance, and charge rising properties while maintaining mechanical strength and environmental safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single latent electrostatic image bearing member is used with four developing units for four colors, then the image forming apparatus can be designed compact at low-production cost, but the image forming processing time increases and printing speed decreases
Solution Approach 1:
The image forming apparatus is divided into multiple independent image forming constitutional elements, each with its own latent electrostatic image bearing member and developing unit. This segmentation allows parallel processing of different colors simultaneously, achieving high-speed image formation while maintaining compact design through modular architecture.
2Productivity
If a plurality of latent electrostatic image bearing members are mounted for parallel processing, then high-speed image formation is achieved, but the main body size of the image forming apparatus increases and production cost increases
Solution Approach 1:
Multiple image forming constitutional elements are integrated into a single compact housing with shared support structures and common power supply systems. The latent electrostatic image bearing members are arranged in a space-efficient configuration, allowing parallel color processing without proportionally increasing the overall apparatus size.
3Productivity
If conventional toners are used for high-speed image formation, then productivity is improved, but mechanical strength and charge stability deteriorate
Solution Approach 1:
The toner uses a composite binder resin system combining polyester resin with specific glass transition temperature ranges and polyester resin containing 1,2-propane diol. This composite material approach provides both the charge stability needed for reliable image formation and the processing characteristics required for high-speed operation, resolving the contradiction between productivity and reliability.
4Use of energy by stationary object
If low-temperature fixing is implemented to save energy, then energy consumption is reduced, but offset resistance and image quality deteriorate
Solution Approach 1:
The toner formulation parameters are optimized with polyester resin having specific softening points (120-160°C and 80-120°C) and controlled glass transition temperature. This parameter optimization enables the toner to maintain adequate offset resistance and image quality at lower fixing temperatures, reducing energy consumption while preserving image formation reliability.
5Reliability
If aromatic oxycarboxylic acid metal compound is used as charge controlling agent, then charge rising property is improved, but environmental safety concerns arise
Solution Approach 1:
The charge controlling agent uses aromatic oxycarboxylic acid metal compound with trivalent or more central metal, optimizing the charge rising properties. The specific metal selection and compound structure are controlled to achieve effective charge control while minimizing environmental harm, balancing performance requirements with environmental safety considerations.
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 high-quality image formation over a long period with improved low-temperature fixing, offset resistance, storage stability, and charge stability, ensuring consistent image quality without color tone changes or abnormalities like reduced image density and background smear.
Implementation Method 1
the binder resin contains a polyester resin (A) having a softening point Tm (A) of 120° C. to 160° C. and a polyester resin (B) having a softening point Tm (B) of 80° C. to less than 120° C.
Implementation Method 2
the charge controlling agent contains an aromatic oxycarboxylic acid metal compound having a trivalent or more central metal
Implementation Method 3
can be obtained by condensation polymerizing an alcohol component substantially composed of only an aliphatic alcohol with a carboxylic acid component
Data Source
AI summary
A toner that is excellent in low-temperature fixing property, offset resistance, storage stability, charge rising property, charge stability with time and pulverizability and allows for forming high-quality images over a long period of time. The toner contains at least a binder resin, a colorant and a charge controlling agent, wherein the charge controlling agent contains an aromatic oxycarboxylic acid metal compound having a trivalent or more central metal, the binder resin comprises a polyester resin (A) having a softening point Tm (A) of 120° C. to 160° C. and a polyester resin (B) having a softening point Tm (B) of 80° C. to less than 120° C., and at least any one of the polyester resins (A) and (B) contains 1,2-propane diol at 65 mol % or more in a divalent alcohol component and can be obtained by condensation polymerizing an alcohol component substantially composed of only an aliphatic alcohol with a carboxylic acid component.