Ink Viscosity Stability via Pigment Surface Functionalization
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Solution Overview
Problem
Active energy ray curable compositions with pigments face challenges in achieving a balance between dispersion stability and discharging properties, particularly in maintaining viscosity stability over time and ensuring effective pigment dispersion.
Innovation Solution
The composition incorporates inorganic pigments like carbon black or titanium oxide with specific surface treatments, optimizing the ratio of hydrophilic functional groups or sulfonic acid groups to specific surface area, which enhances dispersion stability and discharging properties by improving charge repulsion and adsorption affinity with dispersants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pigment-based ink is used for active energy ray curable composition, then durability is improved, but dispersion stability deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the ratio of hydrophilic functional groups to specific surface area of carbon black within 7-42 μmol/m², and sulfonic acid groups to specific surface area of metal oxide within 7-85 μmol/m². This quantitative parameter optimization resolves the contradiction by achieving both high dispersion stability and good discharging properties through controlled surface chemistry of the pigment particles.
Solution Approach 2:
The patent applies local quality by introducing specific functional groups (hydrophilic groups on carbon black, sulfonic acid groups on metal oxide) at the surface level of pigment particles. This localized modification of surface properties enables uniform dispersion while maintaining the inherent durability advantages of pigment-based inks, without requiring bulk material changes.
2Stability of the object's composition
If pigment dispersion is optimized for uniformity, then dispersion stability is improved, but discharging property deteriorates
Solution Approach 1:
The patent resolves this contradiction through precise parameter control of functional group ratios (7-42 μmol/m² for carbon black, 7-85 μmol/m² for metal oxide), which simultaneously optimizes both dispersion stability and discharging properties. The controlled surface functionality enables balanced performance without sacrificing either attribute.
Solution Approach 2:
The patent applies partial action by introducing a controlled, moderate amount of functional groups rather than maximizing surface modification. This partial modification approach achieves sufficient dispersion stability while avoiding excessive surface treatment that would harm discharging properties, maintaining an optimal balance between the two requirements.
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
This approach results in active energy ray curable compositions with improved dispersion stability and discharging properties, maintaining viscosity within a narrow range even after storage, ensuring consistent performance and inkjet discharging capabilities.
Implementation Method 1
optimizing the ratio of hydrophilic functional groups or sulfonic acid groups to specific surface area, which enhances dispersion stability and discharging properties by improving charge repulsion
Implementation Method 2
optimizing the ratio of hydrophilic functional groups or sulfonic acid groups to specific surface area, which enhances dispersion stability and discharging properties by improving charge repulsion and adsorption affinity with dispersants
Implementation Method 3
active energy ray curable composition
Data Source
AI summary
An active energy ray curable composition includes an inorganic pigment and a polymerizable monomer, wherein the inorganic pigment is carbon black having a ratio of the amount of hydrophilic functional group to the specific surface area in a range of from 7 μmol/m2 to 42μmol/m2 or a metal oxide having a ratio of the amount of sulfonic acid group to the specific surface area in a range of from 7 μmol/m2 to 85 μmol/m2, wherein the active energy ray curable composition has a viscosity change rate (ΔV) represented by the following relation 1 from −10 percent by mass to +10 percent by mass:ΔV(%)=|V−V0|/V0×100 relation 1,where V0 represents an initial viscosity at 25 degrees C. and V represents a storage viscosity after the active energy ray curable composition is stored still at 70 degrees C. for 14 days.