Hybrid Polyester-Styrene Acryl Toner for Offset-Free Fixing
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Solution Overview
Problem
Conventional toners using a combination of polyester and styrene-acryl resins in electrophotographic image forming techniques suffer from image staining and fixing offset issues, particularly when printing large numbers of sheets, and winding onto the pressure belt during duplex printing.
Innovation Solution
An image forming method utilizing a toner composed of hybrid resin particles formed by condensation-polymerizing polyvalent carboxylic acids and alcohols in the presence of styrene and acrylic acid ester monomers, followed by radical polymerization, to create a uniform dispersion of polyester and styrene-acryl resins, which are then coagulated with colorant particles, resulting in stable fixing without image staining or belt winding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a toner using styrene-acryl resin is used to achieve low temperature fixability, then fixing at low temperature is improved, but fixing strength deteriorates and image stability is compromised
Solution Approach 1:
The patent uses a composite resin system combining styrene-acryl resin (for low-temperature fixability) with polyester resin (for high-temperature stability and fixing strength). This composite approach allows the toner to achieve both low-temperature fixability and high fixing strength, resolving the contradiction between temperature and reliability.
2Reliability
If polyester resin is used to achieve stable fixing strength, then fixing strength is improved, but low temperature fixability deteriorates
Solution Approach 1:
The patent combines polyester resin (providing fixing strength and thermal stability) with styrene-acryl resin (providing low-temperature fixability). This composite material approach allows simultaneous achievement of both fixing strength and low-temperature processability, resolving the contradiction between reliability and temperature.
3Productivity
If ground toner composed of polyester resin and styrene-acryl resin is used in roll-form heating body and belt-form pressure body, then fixing efficiency is improved, but image staining occurs after continuous printing
Solution Approach 1:
The patent modifies the resin composition parameters by using a specific ratio and molecular weight distribution of polyester and styrene-acryl resins. This parameter optimization prevents resin migration and staining during continuous printing while maintaining high fixing efficiency in the roll-form heating body and belt-form pressure body configuration.
4Stability of the object's composition
If hybrid resin particles are formed by condensation-polymerization and radical polymerization, then uniform dispersion is improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines condensation-polymerization and radical polymerization into a single integrated process step, allowing both resin components to be formed simultaneously in one reactor. This merging of processes achieves uniform dispersion of hybrid resin particles while avoiding the complexity of separate manufacturing steps.
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 method achieves superior print quality without image staining or belt winding, even after 10,000 sheets, and ensures stable fixing strength by leveraging the viscoelasticity of polyester resin and low-temperature fixability of styrene-acryl resin, enabling faithful reproduction of micro-dot and fine-line images over extended durations.
Implementation Method 1
allowing a polyvalent carboxylic acid and a polyvalent alcohol to condensation-polymerize in the presence of a styrene monomer and an acrylic acid ester monomer in an aqueous medium to form the polyester resin
Implementation Method 2
allowing the styrene monomer and the acrylic acid ester monomer to radical-polymerize to form the styrene-acryl resin
Implementation Method 3
which are then coagulated with colorant particles, resulting in stable fixing without image staining or belt winding
Data Source
AI summary
Image forming method comprising a step of fixing a toner image in a fixing device of a contact heating system, wherein the toner comprises a resin which comprises a polyester resin and a styrene-aryl resin and is formed by a process comprising allowing a polyvalent carboxylic acid and a polyvalent alcohol to condensation-polymerize in the presence of a styrene monomer and an acrylic acid ester monomer in an aqueous medium to form the polyester resin and allowing the styrene monomer and the acrylic acid ester monomer to radical-polymerize to form the styrene-acryl resin; the fixing device of a contact heating system comprises a heating roller and a belt-form pressure means.