Block Copolyester Resin Core-Shell Nanoparticles for Toner
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Solution Overview
Problem
There is a need to improve the synthesis of polyester resins and their use in forming emulsion aggregation toners, particularly to control the distribution of crystalline components within toner particles for optimal charging characteristics and to achieve low-melt behavior, as poor crystalline-amorphous polymer combinations can result in toners with unacceptable heat cohesion and charging issues.
Innovation Solution
The process involves forming block copolyester resins by reacting a crystalline polyester with an amorphous polyester, using coupling agents such as anhydrides or bisoxazolines to create copolymers with distinct crystalline and amorphous blocks, which self-assemble into core-shell nanoparticles, preventing crystalline material migration to the toner surface and enhancing charging properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If crystalline polyester is used in toner particles, then low-melt behavior and high gloss are achieved, but charging characteristics deteriorate due to conductivity of crystalline polyester on particle surface
Solution Approach 1:
The invention divides the polyester structure into distinct crystalline blocks and amorphous blocks within a block copolymer architecture. This segmentation allows the crystalline regions to provide low-melt behavior while the amorphous regions maintain charging characteristics, resolving the contradiction between melting point and charging performance.
Solution Approach 2:
The invention creates local quality differences by positioning crystalline polyester blocks in specific regions (interior or surface) and amorphous blocks in complementary regions. This spatial distribution allows different parts of the same polymer to fulfill different functions: crystalline regions for low-melt behavior and amorphous regions for proper charging.
2Temperature
If separate crystalline and amorphous polyesters are used, then low-melt behavior is achieved, but manufacturing complexity increases
Solution Approach 1:
The invention merges separate crystalline and amorphous polyester components into a single block copolymer molecule. This combining eliminates the need for separate processing of multiple polyester materials, simplifying the manufacturing process while maintaining the low-melt behavior provided by the crystalline blocks.
Solution Approach 2:
The invention creates a composite block copolymer material that integrates both crystalline and amorphous polyester characteristics into a single unified material system. This composite approach allows simultaneous achievement of low-melt behavior and manufacturing simplicity through a single material rather than multiple separate materials.
3Temperature
If crystalline polyester migrates to toner surface, then low-melt behavior is enhanced, but charging characteristics worsen due to poor charge from crystalline polyester on surface
Solution Approach 1:
The invention applies local quality by creating a block copolymer where amorphous blocks are positioned to control the distribution and migration of crystalline blocks. This spatial arrangement ensures that crystalline regions provide low-melt behavior without excessive migration to the surface, while amorphous regions maintain proper charging characteristics.
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 results in toners with improved charging characteristics and low-melt behavior, reducing energy costs and reaction times by using a single copolymer instead of separate crystalline and amorphous polyesters, while maintaining high gloss and energy efficiency in electrophotographic printing.
Implementation Method 1
These copolymers may self-assemble in water or a similar media to form nanoparticles suitable for forming toner compositions. In embodiments, the copolymers may self-assemble to form core-shell nanoparticles, with the amorphous block forming the shell and the crystalline block forming the core.
Data Source
AI summary
The present disclosure provides processes for the production of block copolymer polyester resins suitable for use in manufacturing toners. In embodiments, the copolymers include both a crystalline block and an amorphous block, which can self-assemble to form nanoparticles suitable for use in forming toners.