Toner Formulation Using Polyester Resins for Thermal Stability
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Solution Overview
Problem
Conventional toners face a trade-off between low-temperature fixing property and heat-resistant storage stability, with combinations of non-crystalline and crystalline polyester resins leading to degradation in thermal properties and increased oligomer components that cause adhesion issues during manufacturing.
Innovation Solution
A toner formulation using a non-crystalline polyester resin with a tetrahydrofuran soluble component of specific weight-average molecular weight, combined with a crystalline polyester resin, and a methanol extraction process to control oligomer content, ensuring a glass transition temperature difference of 2.0°C or less, thereby maintaining desired thermal properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the glass transition temperature and melt viscosity are reduced to achieve low-temperature fixing property, then low-temperature fixing property is improved, but heat-resistant storage stability deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the weight-average molecular weight of the non-crystalline polyester resin (3,000 to 8,000) and the glass transition temperature (40°C to 60°C) to achieve optimal balance between low-temperature fixing property and heat-resistant storage stability
Solution Approach 2:
The patent uses composite materials by combining non-crystalline polyester resin and crystalline polyester resin in specific proportions (non-crystalline: 70-90 mass%, crystalline: 10-30 mass%) to achieve both low-temperature fixing and heat-resistant storage stability
2Temperature
If a non-crystalline polyester resin and a crystalline polyester resin are used in combination to improve low-temperature fixing property, then low-temperature fixing property is improved, but heat-resistant storage stability deteriorates due to transesterification reaction
Solution Approach 1:
The patent controls the composition parameters by limiting the crystalline polyester resin content to 10-30 mass% and specifying the glass transition temperature range (40°C to 60°C) to prevent excessive transesterification while maintaining low-temperature fixing property
Solution Approach 2:
The patent applies local quality by using a non-modified polyester resin with specific molecular weight characteristics in the dominant phase (70-90 mass%) to maintain stability, while using a smaller amount of crystalline polyester resin (10-30 mass%) to provide low-temperature fixing enhancement
3Temperature
If the weight-average molecular weight of non-crystalline polyester resin is reduced to improve low-temperature fixing property, then low-temperature fixing property is improved, but oligomer component increases causing adhesion and granulation problems
Solution Approach 1:
The patent precisely controls the weight-average molecular weight parameter within the range of 3,000 to 8,000 to achieve the optimal balance between low-temperature fixing property and minimizing oligomer content that causes adhesion and granulation issues
Solution Approach 2:
The patent specifies a particular molecular weight range (3,000 to 8,000) that replicates the optimal balance achieved in previous examples, ensuring consistent low-temperature fixing property without excessive oligomer formation
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 achieves superior low-temperature fixing property and heat-resistant storage stability by minimizing oligomer component elution and adhesion, while optimizing glass transition temperature and melt viscosity.
Implementation Method 1
a transesterification reaction occurs during melt-kneading due to similar composition of the resins
Implementation Method 2
when toner particles are dispersed in an aqueous medium during a manufacturing process, the oligomer component eludes into the aqueous medium
Implementation Method 3
the toner has a glass transition temperature A before an extraction process of the toner with methanol and a glass transition temperature B after the extraction process of the toner with methanol, and a difference between A and B (B - A) is 2.0°C or less
Data Source
AI summary
A toner including a non-crystalline polyester resin and a crystalline polyester resin, wherein a tetrahydrofuran soluble component of the non-crystalline polyester resin has a weight-average molecular weight of 3,000 to 8,000 measured by gel permeation chromatography, and wherein the toner has a glass transition temperature A before an extraction process of the toner with methanol and a glass transition temperature B after the extraction process of the toner with methanol, and a difference between A and B (B - A) is 2.0°C or less.