Electrostatic Toner Resin Composite for Fixing Temperature and Heat Resistance
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Solution Overview
Problem
Existing electrostatic latent image-developing toners face challenges in achieving both low-temperature fixability and heat resistance, as traditional methods often compromise on one property at the expense of the other, and current techniques with amorphous polyester resin as the main component result in reduced heat resistance.
Innovation Solution
The use of a combination of styrene-acrylic resin, amorphous polyester resin, and crystalline polyester resin, with specific absorption peak ratios and cooling rates during the emulsion aggregation method, allows for optimized surface composition and processing conditions to balance low-temperature fixability and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the fixing temperature is reduced to achieve low-temperature fixability, then energy consumption is reduced, but the heat-resistant storage properties deteriorate
Solution Approach 1:
The toner employs a composite resin system comprising three distinct resin types: crystalline polyester resin (providing heat resistance), amorphous polyester resin (providing low-temperature fixability), and styrene-acrylic resin (modulating surface properties). This composite structure enables the toner to simultaneously achieve low fixing temperature (160-180°C) and adequate heat-resistant storage properties by combining the complementary characteristics of different resin materials.
Solution Approach 2:
The invention creates local compositional differences within the toner particles by controlling the distribution of resin components. The amorphous polyester resin and styrene-acrylic resin are positioned preferentially at the particle surface, while the crystalline polyester resin forms the core structure. This local quality differentiation allows the surface to provide low-temperature melting for easy fixing while the core maintains structural integrity for heat resistance.
2Temperature
If amorphous polyester resin is used as the main component to reduce melting temperature, then low-temperature fixability is improved, but heat resistance deteriorates
Solution Approach 1:
Rather than using amorphous polyester resin as the sole or main component, the invention creates a balanced three-component composite where crystalline polyester resin (30-70 wt%) provides the heat-resistant framework, amorphous polyester resin (10-40 wt%) contributes to low melting point, and styrene-acrylic resin (10-40 wt%) modifies surface properties. This composite approach prevents the heat resistance deterioration that occurs when amorphous resin dominates.
Solution Approach 2:
The invention optimizes the quantitative parameters of each resin component to achieve the desired balance. By controlling the weight ratios within specific ranges and adjusting the glass transition temperature and melting point parameters of the resin mixture, the toner achieves both low-temperature fixability and adequate heat resistance, avoiding the extreme parameter values that would cause one property to deteriorate.
3Manufacturing precision
If a narrow particle diameter distribution is achieved for high image quality, then development behavior uniformity is improved, but production complexity increases
Solution Approach 1:
The invention achieves narrow particle diameter distribution through preliminary control of resin particle sizes before the aggregation step. By pre-dispersing the three resin types with controlled size distributions and then aggregating them in a specific sequence (first amorphous polyester, then crystalline polyester, finally styrene-acrylic), the process inherently produces uniform toner particles without requiring complex post-processing sorting or classification equipment.
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
This approach enables the production of toners with enhanced low-temperature fixability and heat resistance, improving image quality and storage properties while maintaining fluidity and image density.
Implementation Method 1
aggregating and fusing at least styrene-acrylic resin particles, amorphous polyester resin particles, and crystalline polyester resin particles by an emulsion aggregation method
Implementation Method 2
cooling an aqueous dispersion of the resultant toner base particles at a cooling rate of 10°C to 30°C/min
Implementation Method 3
the amorphous resin is compatible with the crystalline resin, resulting in a reduction in heat resistance
Data Source
Figure 1
AI summary
An electrostatic latent image-developing toner includes a styrene-acrylic resin, an amorphous polyester resin, and a crystalline polyester resin. The electrostatic latent image-developing toner shows maximum absorption peaks at least in absorption wavenumber ranges of 690 to 710 cm-1, 1190 to 1220 cm-1, and 1230 to 1300 cm-1 in an absorption spectrum measured by attenuated total reflection with a Fourier transform infrared spectrometer. The ratio (P3/P1) of the height (P3) of the maximum absorption peak in the range of 1230 to 1300 cm-1 to the height (P1) of the maximum absorption peak in the range of 690 to 710 cm-1 is 0.02 to 6.00.