Toner Binder Viscoelasticity for Low-Temperature Fixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrostatic charge image developing toners face issues with end part stains on recording media due to non-visual offset, which occurs when isolated toner adheres to the fixing member during low-temperature fixing, and they lack effective low-temperature fixability.
Innovation Solution
The toner particles contain an amorphous polyester resin and a crystalline resin as a binder, with specific molar ratios of constitutional units derived from aliphatic dicarboxylic acid and aliphatic diol, and controlled viscoelasticity to suppress non-visual offset while ensuring low-temperature fixability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If toner uses conventional binder resin composition, then low-temperature fixability is achieved, but end part stains occur due to non-visual offset
Solution Approach 1:
The patent changes the chemical composition parameters of the binder resin by incorporating specific constitutional units (aliphatic dicarboxylic acid units and aliphatic diol units) in controlled proportions (0.5-10.0% molar ratio) to modify the resin's viscoelastic properties and adhesion characteristics, thereby suppressing end part stains while maintaining low-temperature fixability
Solution Approach 2:
The patent uses a composite binder resin system combining amorphous polyester resin with specific crystalline resin components, where the crystalline resin content is controlled at 1-15 parts by mass per 100 parts of amorphous resin, creating a material that exhibits both low-temperature fixability and reduced non-visual offset
2Reliability
If toner particles have high adhesion to fixing member, then low-temperature fixability is improved, but non-visual offset increases causing end part stains
Solution Approach 1:
The patent modifies the viscoelastic parameters of the binder resin by controlling the molar ratio of constitutional units (aliphatic dicarboxylic acid and aliphatic diol) within 0.5-10.0%, which optimizes the balance between adhesion to the fixing member and resistance to non-visual offset
Solution Approach 2:
The patent introduces specific functional groups (aliphatic dicarboxylic acid and aliphatic diol units) at controlled local concentrations within the polymer chain to create regions with different adhesion characteristics, allowing the resin to adhere sufficiently to the fixing member while minimizing non-visual offset
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 effectively suppresses end part stains on recording media by enhancing toner deformability and reducing adhesion to the fixing member, maintaining low-temperature fixability and improving image quality.
Implementation Method 1
in a dynamic viscoelasticity measurement of the toner particles in a case where a temperature is raised from 30°C to 120°C, a minimal value tan δ(min) of a loss tangent, present at 50°C or higher and 80°C or lower
Implementation Method 2
a minimal value tan δ(min) of a loss tangent, present at 50°C or higher and 80°C or lower, is 0.50 or more and 1.00 or less
Data Source
Figure 1
Figure 2
AI summary
An electrostatic charge image developing toner contains toner particles that contain an amorphous polyester resin and a crystalline resin as a binder resin, in which the toner particles contain, as the amorphous polyester resin, an amorphous polyester resin (S) that has at least one of a constitutional unit derived from an aliphatic dicarboxylic acid represented by Structural formula (A) or a constitutional unit derived from an aliphatic diol represented by Structural formula (B), a proportion of a total of the constitutional unit derived from the aliphatic dicarboxylic acid represented by Structural formula (A) and the constitutional unit derived from the aliphatic diol represented by Structural formula (B) with respect to all constitutional units constituting the amorphous polyester resin is 0.5% or more and 10.0% or less in terms of molar ratio, and in a dynamic viscoelasticity measurement of the toner particles in a case where a temperature is raised from 30°C to 120°C, a minimal value tan δ(min) of a loss tangent is present at 50°C or higher and 80°C or lower and is 0.50 or more and 1.00 or less. In Structural formulae (A) and (B), nA and nB each independently represent an integer of 2 or more and 12 or less.