Water-Based Ink Set Preventing Pigment Coagulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ink-jet recording technologies face challenges in achieving vivid color images with dye inks and high density, high contrast images with pigment inks while preventing coagulation and bleeding, particularly when combining pigment and dye inks, which can lead to clogged nozzles and operational failures.
Innovation Solution
A water base ink set comprising a black ink with a self-dispersing black pigment and a yellow ink containing a water-soluble anionic yellow dye with limited counter ions and a surfactant based on amine, both using water-soluble polyvalent alcohol alkyl ethers, to maintain electrostatic repulsive forces and prevent coagulation, ensuring stable dispersion and preventing bleeding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pigment ink and dye ink are combined to achieve both vivid color and high density images, then image quality is improved, but coagulation occurs causing nozzle clogging
Solution Approach 1:
The patent modifies the chemical parameters of the ink formulation by incorporating specific surfactants and controlling counter ion concentrations. This changes the electrostatic properties of the pigment particles, maintaining their negative charge even in the presence of cationic dyes, thereby preventing coagulation while allowing both pigment and dye to coexist in the same ink formulation
Solution Approach 2:
The patent introduces surfactants as intermediary substances that mediate between the pigment particles and cationic dyes. These surfactants form protective layers around pigment particles, preventing direct electrostatic interaction with cationic dyes and thus preventing coagulation while allowing the ink to maintain both vivid color and high density properties
2Illumination intensity
If dye is used as coloring agent, then image vividness is improved, but ink spreads nonuniformly causing jaggy edges
Solution Approach 1:
The patent changes the physical parameters of the dye molecules through chemical modification or selection of specific dye types with controlled molecular sizes and structures. This allows the dye to permeate paper uniformly while still producing vivid colors, preventing the nonuniform spreading that causes jaggy edges
3Manufacturing precision
If pigment is used as coloring agent, then image density and contrast are improved, but dispersion becomes unstable causing coagulation
Solution Approach 1:
The patent introduces surfactants as intermediary substances that mediate between the pigment particles and the aqueous medium. These surfactants form stable protective layers around pigment particles, preventing aggregation and maintaining uniform dispersion throughout the ink, thereby preserving both image density and dispersion stability
Solution Approach 2:
The patent modifies the surface charge parameters of pigment particles through chemical treatment or selection of specifically charged pigments. By maintaining a consistent negative charge on pigment surfaces and controlling the ionic environment, the patent ensures stable electrostatic repulsion between particles, preventing coagulation while maintaining high image density
4Illumination intensity
If cationic dye is used in color ink, then color vividness is improved, but electrostatic repulsion of pigment is cancelled causing coagulation
Solution Approach 1:
The patent introduces surfactants as intermediary substances that form protective layers around negatively charged pigment particles. These surfactant layers act as barriers that prevent cationic dyes from directly neutralizing the pigment charge, thereby maintaining electrostatic repulsion and preventing coagulation while allowing cationic dyes to provide vivid colors
Solution Approach 2:
The patent modifies the ionic environment parameters by controlling counter ion concentrations and selecting specific surfactant types. This creates an electrostatic shield around pigment particles, maintaining their negative charge characteristics even in the presence of cationic dyes, thus preserving both color vividness and pigment stability
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 ink set achieves vivid color and high density images without pigment coagulation or bleeding, maintaining nozzle functionality and operational integrity, and allows for practical use without increasing manufacturing costs.
Implementation Method 1
a black ink containing a self-dispersing black pigment, which is dispersed in a solvent by having a negative charge
Implementation Method 2
a surfactant based on amine represented by the following general formula (1)
Implementation Method 3
both using water-soluble polyvalent alcohol alkyl ethers, to maintain electrostatic repulsive forces and prevent coagulation, ensuring stable dispersion and preventing bleeding
Data Source
AI summary
A water base ink set for ink-jet recording includes a black ink containing a negatively charged self-dispersing black pigment and a water-soluble polyvalent alcohol alkyl ether; and a yellow ink containing a water-soluble anionic yellow dye in which a number of counter ion or ions per one molecule is not more than 3, a surfactant based on amine represented by the following general formula (1), and a water-soluble polyvalent alcohol alkyl ether;R—N—(CH2CH2O)xH(CH2CH2O)yH (1)wherein R represents an alkyl group or an alkenyl group having a number of carbons of 8 to 18, and x+y is 5 to 15. Accordingly, the water ink set in which no bleeding or no coagulation of the pigment occur is provided.