Water-Based Pigment Ink Balancing Stability and Image Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inks face challenges in achieving both preservation stability and image density, often requiring multiple compounds that increase production costs and may compromise solvent compatibility, leading to potential instability.
Innovation Solution
A water-based ink formulation using a specific surfactant with a butylene oxide chain and ethylene oxide chains, combined with a water-soluble solvent of controlled hydrophobicity, to enhance pigment dispersibility and agglomeration on the recording medium, thereby achieving high preservation stability and image density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pigments are highly dispersed in the solvent to improve preservation stability, then preservation stability is improved, but image density deteriorates
Solution Approach 1:
The ink composition is segmented into multiple functional components: a dispersant (polymer compound) for preservation stability, and specific surfactants (General Formula (1) and General Formula (2)) for controlling pigment aggregation on the recording medium. This segmentation allows each component to independently optimize its function without interfering with others.
Solution Approach 2:
The patent specifies precise parameter ranges for each component: dispersant at 0.01-5 mass%, surfactant of General Formula (1) at 0.001-0.5 mass%, and surfactant of General Formula (2) at 0.001-0.5 mass%. These controlled parameter changes enable simultaneous achievement of pigment dispersion stability and controlled aggregation for high image density.
2Manufacturing precision
If multiple compounds are added to achieve both preservation stability and image density, then both properties are improved, but device complexity and production cost increase
Solution Approach 1:
The patent merges the functions of multiple compounds into a coordinated system where a dispersant and two specific surfactants work together. The dispersant provides baseline stability while the surfactants fine-tune the pigment behavior, achieving both preservation stability and image density through synergistic combination rather than separate treatments.
Solution Approach 2:
The surfactants of General Formula (1) and General Formula (2) serve multiple functions: they stabilize pigment dispersion in the ink reservoir and simultaneously control pigment aggregation on the recording medium. This multi-functionality reduces the need for separate additives for each function.
3Ease of manufacture
If conventional solvents are used with multiple compounds, then production is simplified, but preservation stability may be compromised due to solvent incompatibility
Solution Approach 1:
The patent specifies precise parameter ranges for solvent composition (total content of alcohols, glycols, and carboxylic acids at 5-50 mass%) to ensure compatibility with the dispersant and surfactants. This controlled parameter change maintains preservation stability while using conventional, easily manufacturable solvents.
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 achieves both high preservation stability and image density, with the surfactant ensuring pigment dispersion and the solvent promoting agglomeration, resulting in clear and stable images on various recording media.
Implementation Method 1
a surfactant represented by the following general formula (1)... enhances the dispersibility of pigments in the solvent by forming π-π stacking with the pigment
Implementation Method 2
a water-soluble solvent having a log Kow of -1.0 or more and 0.85 or less... enhances the affinity between the cellulose fiber forming the recording medium and the pigment
Implementation Method 3
The former enhances the dispersibility of pigments in the solvent by forming π-π stacking with the pigment
Implementation Method 4
a surfactant represented by the following general formula (1)... a water-soluble solvent having a log Kow of -1.0 or more and 0.85 or less... achieving both the preservation stability and image density
Data Source
AI summary
An ink includes: a surfactant having a main skeleton represented by the following general formula (1); a water-soluble solvent having a log Kow of -1.0 or more and 0.85 or less; a pigment; and water. A content of the water-soluble solvent is 20 mass% or more and 50 mass% or less. HO[CH2CH2O]x-[CH2CH2CH2CH2O]y-[CH2CH2O]xOH ··· (1) (In the general formula (1), x represents an integer of 4 or more and 10 or less, and y represents an integer of 1 or more and 5 or less.)