Polymeric Charge Control Agent for Toner Charging Speed
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Solution Overview
Problem
Conventional charge control agents in electrophotographic recording methods fail to provide sufficient charge-providing properties for higher speed and image quality, leading to issues like 'fog' and streaky density non-uniformity due to toner charging with reverse polarity.
Innovation Solution
A novel polymerizable monomer represented by a specific formula, which upon polymerization, forms a polymeric compound that acts as an effective charge control agent, improving charge-providing performance by controlling triboelectric charging and reducing reverse-polarity toner formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional charge control agents (metal complexes of salicylic acid, alkylsalicylic acids, or benzilic acid) are used, then the toner can be charged, but the charge-providing properties are insufficient for higher speed and image quality requirements
Solution Approach 1:
The patent modifies the chemical structure of salicylic acid derivatives by introducing specific substituents (R1-R6 groups) and polymerizing them to create a polymeric charge control agent. This structural parameter change enhances both the charging speed and charge characteristics, resolving the contradiction between productivity and reliability in charging performance.
Solution Approach 2:
The invention creates a composite polymeric charge control agent that combines multiple functional groups (salicylic acid units with specific substituents) into a single polymer structure. This composite approach allows simultaneous optimization of charging speed and charge stability, addressing the contradiction between fast charging and reliable charge characteristics.
2Reliability
If conventional charge control agents are used, then the toner can be charged, but reverse polarity charging occurs causing fog and streaky density non-uniformity
Solution Approach 1:
The patent changes the chemical parameters of the charge control agent by polymerizing salicylic acid derivatives with specific substituent patterns. This structural modification ensures consistent charge polarity and prevents reverse charging, thereby eliminating fog and streaky density non-uniformity while maintaining reliable charge control.
Solution Approach 2:
The invention converts the potential harm of reverse polarity charging into a benefit by designing a polymeric structure that inherently prevents reverse charging. The specific polymer architecture ensures unidirectional charge provision, transforming the problem of charge instability into a solution that guarantees consistent charge polarity and eliminates image defects.
3Reliability
If a polymeric compound composed of sulfonic acid group monomer units is used as charge control agent, then charging stability improves, but compatibility with binder resin and overall charge-providing performance remain insufficient
Solution Approach 1:
The patent creates a composite polymeric charge control agent that integrates salicylic acid units with specific substituents into a polymer structure. This composite design provides both charging stability and improved compatibility with binder resin, resolving the contradiction between reliability and adaptability by combining multiple functional characteristics in a single material system.
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 polymeric compound enhances charge-providing properties, including faster charging rise and saturated charge quantity, while minimizing toner charging with reverse polarity, resulting in higher image density and reduced 'fog' in electrophotographic images.
Implementation Method 1
a charge control agent capable of providing the toner with positive charges or negative charges is mixed into toner particles to control the chargeability of the toner
Data Source
AI summary
A polymerizable monomer is provided which is represented by the following formula (1):wherein R1 represents a hydrogen atom or an alkyl group; A represents —CO— or —SO2—; and the moiety represented by the formula (1) is, at the part shown by an asterisk *, linked to a moiety represented by the following formula (2), at any position of a, b, c or d thereof;wherein the sites among a, b, c and d at which the moiety represented by the formula (2) is not linked to the moiety represented by the formula (1) each has a hydrogen atom or a substituent selected from the group consisting of an alkyl group, an alkoxy group and a sulfonic acid group, or any of which may connect at mutually adjoining positions to form a ring.