Ink Composition Low-Temperature Freezing and VOC Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aqueous inks with self-dispersion type pigments used in ink jet recording face challenges with freezing issues, leading to potential damage of ejection heads due to high freezing points, and there is a need for an ink composition that maintains low-temperature characteristics and ejection stability while reducing volatile organic compounds (VOC) generation.
Innovation Solution
An ink composition comprising 3-methyl-1,5-pentanediol, trimethylolpropane, water, and a self-dispersion type pigment, with a mass ratio of trimethylolpropane to 3-methyl-1,5-pentanediol between 0.12 and 2, and limited 1,2-hexanediol content, which enhances low-temperature and ejection characteristics and reduces VOC generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the content of resin is reduced to increase pigment concentration, then pigment concentration is improved, but freezing point increases and low-temperature characteristics worsen
Solution Approach 1:
The patent changes the chemical composition parameters of the ink by specifying precise ratios of polyol components (trimethylolpropane to 3-methyl-1,5-pentanediol mass ratio of 0.12 to 2) and limiting 1,2-hexanediol content to 0.5% or less. This parameter optimization allows achieving both high pigment concentration (4 wt% or more) and low freezing point, resolving the contradiction between pigment concentration and low-temperature characteristics
Solution Approach 2:
The patent uses a composite solvent system combining multiple polyols (trimethylolpropane, 3-methyl-1,5-pentanediol, and limited 1,2-hexanediol) with water and self-dispersion type pigment. This composite material approach creates synergistic effects where the specific combination and ratio of components achieve both high pigment solubility/concentration and depressed freezing point, simultaneously improving both contradictory properties
2Quantity of substance
If self-dispersion type pigment is used to increase pigment concentration, then printing density is improved, but ejection head damage risk increases due to freezing
Solution Approach 1:
The patent optimizes the chemical composition parameters including polyol ratios (trimethylolpropane to 3-methyl-1,5-pentanediol mass ratio of 0.12 to 2) and 1,2-hexanediol content (0.5% or less) to achieve a formulation that maintains liquid state at low temperatures while supporting high pigment concentration (4 wt% or more), thereby preventing freezing cracks in the ejection head and ensuring reliability
Solution Approach 2:
The patent uses a specifically formulated polyol-water mixture as an intermediary medium that mediates between the self-dispersion type pigment and the ejection head system. This intermediary composition prevents freezing while maintaining pigment dispersion stability, protecting the ejection head from freezing damage while enabling high pigment concentration for good printing density
3Stability of the object's composition
If traditional ink composition is used, then ejection stability is maintained, but VOC generation increases
Solution Approach 1:
The patent changes the composition parameters by using a water-based formulation with self-dispersion type pigment and controlled polyol content (total polyol 2-20 wt%, with specific ratios), eliminating or minimizing organic solvents that generate VOC. This parameter change maintains ejection stability through proper viscosity control while significantly reducing VOC generation
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 composition effectively prevents freezing cracks in ejection heads, maintains excellent ejection characteristics, and reduces VOC emissions, even in low-temperature environments, while allowing for high pigment concentration and improved image quality.
Implementation Method 1
when the content of the resin is reduced, the freezing point of the ink tends to be high and the ink tends to freeze easily
Data Source
AI summary
An ink composition includes 3-methyl-1,5-pentanediol; trimethylolpropane; water; and a pigment, in which no more than 0.5% by mass of 1,2-hexanediol is contained, and a mass ratio of the trimethylolpropane to the 3-methyl-1,5-pentanediol is 0.12 or more and 2 or less.