Aqueous Ink Stability via Polyamine Chelation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aqueous inks for inkjet recording face issues with clogging and reduced ejection reliability due to the presence of multivalent metal ions, which cause aggregation and deposition on printer head components, leading to decreased droplet speed and storage stability.
Innovation Solution
A method for producing an aqueous pigment dispersion by mixing a pigment with a pigment dispersant and an alkylene oxide adduct having a polyamine structure, which chelates multivalent metal ions, thereby reducing their presence and preventing aggregation, without the need for particles with chelate forming groups or fibrous resins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If multivalent metal ions are present in aqueous ink, then pigment dispersion can be achieved, but aggregation and deposition occur on printer head components
Solution Approach 1:
A chelating agent is introduced as an intermediary substance that binds to multivalent metal ions, preventing them from reacting with anions to form aggregates. The chelating agent acts as a mediator between metal ions and other ink components, controlling the interaction to maintain stability while preventing harmful aggregation.
Solution Approach 2:
The chemical environment parameters of the ink are changed by adjusting pH levels and adding chelating agents that alter the binding characteristics of metal ions. This changes the chemical state of metal ions from a harmful condition (forming aggregates) to a controlled condition (chelated and stable).
2Reliability
If particles with chelate forming groups are used to remove multivalent metal ions, then aggregation is prevented, but the manufacturing process becomes more complex
Solution Approach 1:
The harmful multivalent metal ions are extracted from the ink system by binding them with chelating agents. The metal ions are effectively removed from the active components of the ink, isolating them in a stable chelated form that prevents aggregation.
Solution Approach 2:
Chemical parameters such as pH and chelating agent concentration are optimized to achieve effective metal ion removal without requiring complex manufacturing steps. The process uses controlled chemical reactions rather than mechanical or multi-step procedures.
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 results in an aqueous ink with reduced multivalent metal ions, improving the stability and reliability of inkjet recording by minimizing particle size and aggregation, thus enhancing ejection performance and storage stability.
Implementation Method 1
an alkylene oxide adduct having a polyamine structure, which chelates multivalent metal ions
Data Source
AI summary
Provided is a method for producing an aqueous pigment dispersion including a step of dispersing a mixture containing a pigment, an anionic group-containing organic polymer compound, a basic compound, and from 1% to 500% by mass of alkylene oxide adduct having a polyamine structure with respect to the pigment into water. The step of dispersing includes Step 1 of kneading a mixture which contains a pigment, an anionic group-containing organic polymer compound, a basic compound, and from 1% to 500% by mass of alkylene oxide adduct having a polyamine structure with respect to the pigment, and which contains no water or water equal to or less than 30% by mass with respect to a solid content thereof, and Step 2 of dispersing a kneaded material obtained in Step 1 into water.