Polyester Toner Composition for High-Gloss Chromogenicity
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Solution Overview
Problem
Existing toners used in electrophotographic full-color copiers face challenges in achieving high chromogenicity, particularly when producing high-gloss printed materials, due to colorant aggregation during the fixing process at high temperatures.
Innovation Solution
A toner formulation comprising a colorant, a polyester resin with an aromatic ring concentration of 50 to 70 mol%, calcium carbonate particles coated with a fatty acid, and a specific particle size range, which prevents colorant aggregation during fixing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high temperature fixing is used to produce high-gloss printed matter, then gloss quality is improved, but colorant aggregation occurs and chromogenicity deteriorates
Solution Approach 1:
The patent introduces a specific polyester resin as an intermediary substance between the colorant and the high-temperature fixing environment. This resin has controlled molecular weight and aromatic ring concentration that prevents colorant aggregation while allowing high-gloss fixation, thus mediating between the conflicting requirements of gloss quality and chromogenicity maintenance
2Quantity of substance
If colorant amount is increased to improve image density, then image quality is improved, but colorant aggregation during fixing worsens and chromogenicity decreases
Solution Approach 1:
The patent changes the chemical parameters of the binder resin system by specifying polyester resin with controlled molecular weight (5,000-20,000) and aromatic ring concentration (50-70 mol%). These parameter changes enable the resin to maintain colorant dispersion at higher colorant loadings without aggregation, thus improving image density while preserving chromogenicity
3Ease of manufacture
If conventional binder resin is used to reduce cost, then manufacturing cost is reduced, but colorant dispersion is insufficient and chromogenicity is poor
Solution Approach 1:
The patent creates a composite binder resin system combining polyester resin with specific molecular weight and aromatic ring concentration characteristics. This composite material approach achieves better colorant dispersion and chromogenicity than conventional resins while maintaining cost-effectiveness through optimized resin selection rather than expensive alternative materials
Data Source
AI summary
A toner comprising a toner particle comprising a colorant, a binder resin, and calcium carbonate particles, wherein an amount of the colorant in the toner particle is from 1.0 to 20.0% by mass; the binder resin comprises a polyester resin; the polyester resin has an aromatic ring concentration of from 50 to 70 mol %; a surface of the calcium carbonate particles is coated with a fatty acid; an amount of the calcium carbonate particles in the toner particle is from 1.0 to 15.0% by mass; a number average particle diameter of the calcium carbonate particles is from 150 nm to 800 nm.