Aromatic Amide Dispersants for Stable Pigment Dispersion
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Solution Overview
Problem
Existing dispersants fail to provide stable dispersions of carbon black and inorganic pigments, leading to issues such as agglomeration, settling, and poor adhesion in aqueous and polar organic media, which affect the quality and resolution of printed products.
Innovation Solution
Aromatic amide dispersants with a tertiary amide pendant group linked to a solubilizing chain are used to enhance dispersion stability, reducing viscosity and particle size, and improving color strength and gloss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional dispersants are used, then pigment dispersion is achieved, but dispersion stability is poor leading to agglomeration and settling
Solution Approach 1:
The patent modifies the chemical structure of dispersants by introducing aromatic amide groups with specific substituents (R1-R6) and functional groups (carboxylic acid, sulfonic acid, or their salts) to change the chemical parameters of the dispersant. This structural modification enables the dispersant to form more stable complexes with pigment particles, preventing agglomeration and settling while maintaining compatibility with the liquid medium.
Solution Approach 2:
The dispersant is designed as a composite molecular structure combining multiple functional elements: aromatic amide core, carboxylic acid or sulfonic acid groups, and various substituent groups (R1-R6). This composite structure allows the dispersant to simultaneously interact with both pigment particles and the liquid medium, creating a stable dispersion system that resists agglomeration and settling.
2Stability of the object's composition
If dispersant concentration is increased to improve stability, then dispersion quality improves, but viscosity increases
Solution Approach 1:
The patent optimizes the molecular parameters of the dispersant including the size and nature of substituent groups (R1-R6), the aromatic ring structure, and the ionizable group characteristics. These parameter optimizations allow the dispersant to achieve effective stabilization at lower concentrations, minimizing the viscosity increase while maintaining dispersion stability.
Solution Approach 2:
The patent utilizes ionizable groups (carboxylic acid or sulfonic acid) that can be protonated or deprotonated to create electrostatic repulsion between dispersant molecules and pigment particles. This electrical charge mechanism provides strong stabilization effectiveness at low dispersant concentrations, avoiding the need for high concentrations that would increase viscosity.
3Manufacturing precision
If dispersant is used to reduce particle size, then dispersion quality improves, but manufacturing complexity increases
Solution Approach 1:
The dispersant molecule is segmented into distinct functional regions: the aromatic amide core, the ionizable acid groups, and the various substituent groups (R1-R6). Each segment performs a specific function in the particle size reduction mechanism, allowing the complex overall structure to be understood and designed through modular functional elements that work together to achieve precise particle size control.
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 aromatic amide dispersants achieve stable dispersions with reduced particle size and distribution, improved brightness, and enhanced gloss, while maintaining stability under ambient and high temperature conditions.
Implementation Method 1
a polymeric dispersant having an aromatic ring with acid functionality chemically linked via an amide linkage to a tertiary amide pendant group linked to at least one solubilizing chain
Implementation Method 2
linked to at least one solubilizing chain
Data Source
AI summary
The present invention relates to a polymeric aromatic amide dispersant, and a composition containing a particulate solid, an aqueous or polar organic medium, and a polymeric aromatic amide dispersant having at least one tertiary amide linking group connecting through a carbonyl group of the amide to an aromatic ring having a residual carboxylic acidic group thereon. The invention further provides compositions for millbases, dispersions, coatings and inks.