Toner Binder Polyester Resin Fixability Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Toner binders for electrophotography face challenges in achieving a combination of low-temperature fixability, heat-resistant storage stability, and moisture heat-resistant storage stability, while also minimizing staining of equipment components like developer tanks.
Innovation Solution
A toner binder comprising a polyester resin with specific constitutional units, including a polycarboxylic acid and a polyhydric alcohol, esterified with monocarboxylic acid or monohydric alcohol, with a controlled ester group concentration and hydroxy value, along with a colorant and a mold release agent, to achieve the desired stability and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If an attempt is made to improve low-temperature fixability, then low-temperature fixability is improved, but heat-resistant storage stability and moisture heat-resistant storage stability deteriorate
Solution Approach 1:
The invention changes the chemical composition parameters of the polyester resin by controlling the molar ratio of propylene glycol to diol with aromatic ring (5/95 to 70/30), the ester group concentration (16 to 30% by weight), and the hydroxy value (1 to 30 mgKOH/g). These parameter adjustments optimize the balance between low-temperature fixability and storage stability under heat and humidity conditions.
Solution Approach 2:
The invention uses a composite polyester resin structure combining aliphatic components (polycarboxylic acid and propylene glycol) for low-temperature fixability with aromatic components (diol having aromatic ring) for storage stability. This composite structure integrates the advantages of both aliphatic and aromatic polymers to resolve the contradiction between fixability and stability.
2Reliability
If an attempt is made to improve heat-resistant storage stability and moisture heat-resistant storage stability, then heat-resistant storage stability and moisture heat-resistant storage stability are improved, but low-temperature fixability deteriorates
Solution Approach 1:
The invention optimizes the chemical composition parameters within specific ranges: ester group concentration of 16 to 30% by weight and hydroxy value of 1 to 30 mgKOH/g. These parameter settings ensure sufficient storage stability while maintaining adequate low-temperature fixability, preventing the deterioration of fixability when improving storage stability.
Solution Approach 2:
The invention introduces local aromatic ring structures through the diol component at controlled proportions (molar ratio of propylene glycol to diol with aromatic ring: 5/95 to 70/30). These localized aromatic segments provide heat and moisture resistance without compromising the overall low-temperature fixability of the polyester resin matrix.
3Reliability
If conventional toner binders are used to achieve low-temperature fixability and storage stability, then fixability and storage stability are improved, but staining of equipment components such as developer tanks occurs
Solution Approach 1:
The invention extracts and eliminates the staining components from the toner binder system by carefully selecting and controlling the polyester resin composition. The specific composition parameters (ester group concentration 16-30%, hydroxy value 1-30 mgKOH/g, and controlled aromatic content) prevent the formation of staining substances while maintaining the required fixability and storage stability.
Solution Approach 2:
The invention converts the potential harm of aromatic components (which can cause staining) into a benefit by precisely controlling their content through the specified molar ratio range. The aromatic rings provide necessary storage stability while their controlled quantity prevents excessive staining, thus converting a potentially harmful factor into a beneficial one.
Data Source
Figure 1
AI summary
A toner binder comprising a polyester, the end of which is partially esterified with a monocarboxylic acid and/or a monohydric alcohol, the polyhydric alcohol component of which comprises a C3 alkylene glycol (a21) and an aromatic-ring-bearing diol (a22) at an (a21)/(a22) molar ratio of 5/95 to 70/30, and which has an ester group concentration of 16 to 30wt% and satisfies a specific relationship between the ester group concentration and the hydroxy value. The toner binder combines low-temperature fixability and storage stability under high-temperature conditions or heat-temperature and -humidity conditions, and exhibits excellent durability.