Modified Polyester Toner for High-Speed Image Density
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Solution Overview
Problem
Current toners for high-speed image forming methods face challenges in achieving sufficient image density and glossiness while maintaining low-temperature fixability and productivity, as existing methods require complex processes and multiple steps.
Innovation Solution
A toner comprising a modified polyester resin with a specific structure, represented by Formula (1a) or (1b), is developed, which is manufactured through a process involving radical polymerization and aggregation to form a core/shell structure, enhancing charge stability and image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional copolymerization methods are used to introduce sulfonic acid groups into polyester resin, then charge stability is improved, but manufacturing complexity increases and productivity decreases
Solution Approach 1:
The patent changes the chemical parameter approach from conventional copolymerization to graft polymerization using sodium 2-acrylamide-2-methylpropanesulfonate as a grafting agent. This parameter change simplifies the manufacturing process while maintaining charge stability, directly resolving the contradiction between reliability and productivity
Solution Approach 2:
The patent extracts the essential functional requirement (sulfonic acid groups for charge stability) from the complex copolymerization process and introduces it through a simpler grafting method. This separates the charge-stabilizing function from the complex synthesis process, improving productivity while maintaining reliability
2Productivity
If process speed is increased for high-speed image forming, then productivity is improved, but image density and glossiness deteriorate
Solution Approach 1:
The patent creates a composite toner structure combining polyester resin with grafted polyacrylamide-sulfonate chains. This composite material provides both the friction charging needed for high-speed processing and the electrostatic latent image development capability for high image density and glossiness, resolving the contradiction between productivity and manufacturing precision
3Quantity of substance
If friction charging is used to fully charge toner for high-speed image forming, then charge amount is improved, but initial image density rise becomes late
Solution Approach 1:
The patent segments the charging mechanism into two distinct components: friction charging for bulk charge accumulation and electrostatic latent image formation for rapid initial density rise. The grafted sulfonic acid groups enable the electrostatic component, allowing both high charge amount and fast initial image appearance, resolving the time loss contradiction
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 toner achieves negligible image density reduction and high glossiness in high-speed image forming, while simplifying the manufacturing process and reducing steps, thereby improving productivity and image quality.
Implementation Method 1
a polymerizable monomer having a functional group selected from a group of a sulfonic acid group, a sulfonic salt group, a sulfonic acid ester group
Implementation Method 2
a method of manufacturing the toner; and an image forming method employing the toner
Data Source
AI summary
A toner comprising a modified polyester resin containing a structure represented by Formula (1a) or (1b), wherein, in Formula (1a) and (1b), R1 represents a hydrogen atom, a methyl group, or an ethyl group, R2 represents an aliphatic hydrocarbon which may be branched, or an aromatic hydrocarbon, and R3 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.