Polyester Toner with Modified Rosin for Low-Temperature Fixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional toners for high-speed electrophotographic printing systems face challenges in achieving low-temperature fixability, offset resistance, heat-resistant storage stability, and smear resistance on developing rollers, while also being energy-efficient and productive, with existing solutions either being inferior in performance or generating odors.
Innovation Solution
A toner comprising a polyester-based resin obtained by polycondensation of an alcohol component with a carboxylic acid component containing modified purified rosin, where the alcohol component includes 1,2-propanediol in high amounts, and the resin undergoes elongation or crosslinking reactions to form a dispersion liquid with a specific particle size distribution and circularity, enhancing fixability and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a linear polyester resin with defined molecular weight is used, then low-temperature fixability is improved, but productivity and pulverizability deteriorate
Solution Approach 1:
The invention changes the molecular weight parameter of the polyester resin to a specific range (5,000 to 50,000) that balances low-temperature fixability with good pulverizability. It also introduces crosslinking density as a new parameter to control particle strength and flowability, resolving the contradiction between fixability and productivity
Solution Approach 2:
The invention creates a composite structure by forming a coating layer on toner particles that contains crosslinked polyester resin. This composite approach allows the core to provide good pulverizability while the coating layer provides low-temperature fixability, thus resolving the contradiction
2Temperature
If rosins are used to improve low-temperature fixability, then fixability is improved, but odor generation increases
Solution Approach 1:
The invention changes the chemical composition parameters by specifying exact proportions of carboxylic acid components (5-30 mass%) and phenolic components (70-45 mass%) in the polyester resin. This compositional parameter adjustment achieves low-temperature fixability without using rosins, thereby eliminating odor generation
Solution Approach 2:
The invention replaces traditional rosin-based binders with a specifically formulated polyester resin that is free from odorous components. This substitution eliminates the harmful odor factor while maintaining the required fixability performance
3Productivity
If high printing speed is achieved, then productivity is improved, but smear resistance on developing rollers deteriorates
Solution Approach 1:
The invention changes the surface properties of toner particles by controlling particle morphology (sphericity of 0.93 or more) and introducing crosslinked structures. These parameter changes enhance smear resistance even at high printing speeds up to 120 sheets per minute
Solution Approach 2:
The invention addresses smear resistance by adding a temporal dimension - specifying that the toner must maintain its properties under high-speed printing conditions (100-120 sheets/min). The crosslinked coating layer provides dimensional stability that prevents smear formation under these high-speed conditions
4Productivity
If conventional toner formulations are used for high-speed printing, then printing speed is improved, but heat-resistant storage stability deteriorates
Solution Approach 1:
The invention creates a composite structure with a crosslinked coating layer on toner particles. This composite approach provides heat-resistant storage stability (blocking resistance) even at high printing speeds by forming a protective barrier that prevents particle aggregation under thermal stress
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 improved low-temperature fixability, offset resistance, and heat-resistant storage stability, while reducing odor generation and improving productivity in high-speed printing systems, with enhanced smear resistance on developing rollers.
Implementation Method 1
a polyester-based resin obtained by polycondensation of an alcohol component with a carboxylic acid component containing modified purified rosin
Implementation Method 2
the resin undergoes elongation or crosslinking reactions to form a dispersion liquid with a specific particle size distribution and circularity
Data Source
AI summary
An electrostatic image developing toner including a resin fine particle, and a toner material containing a polyester-based resin, wherein the electrostatic image developing toner is obtained by dissolving and/or dispersing the toner material containing the polyester-based resin in an organic solvent to prepare a toner material liquid, and dispersing the toner material liquid in an aqueous solvent containing the resin fine particle, and wherein the polyester-based resin contains a polyester resin obtained by polycondensation of an alcohol component with a carboxylic acid component containing a modified purified-rosin.