Aqueous Inkjet Ink Colloidal Stability via Resin Mediators
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Solution Overview
Problem
White inks in inkjet color sets face challenges due to early sedimentation of titanium oxide nanoparticles, leading to colloidal instability, short shelf-life, and reduced print opacity, which affects jetting performance and substrate coating.
Innovation Solution
The development of aqueous inkjet ink compositions that include a solvent system comprising water, specific organic solvents, and resin particles, which enhances colloidal stability, jetting performance, and opacity, while maintaining durability and water-fastness on various substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If titanium oxide nanoparticles are used in low viscosity aqueous mixtures, then jetting performance is improved, but colloidal stability deteriorates leading to early sedimentation
Solution Approach 1:
The patent introduces resin particles as intermediary components that interact with titanium oxide nanoparticles through surface forces. These resin particles act as mediators that prevent direct nanoparticle aggregation and sedimentation, while maintaining the low viscosity required for jetting performance. The resin particles create a stabilizing matrix that keeps nanoparticles dispersed without requiring high viscosity binders.
Solution Approach 2:
The invention creates a composite inkjet ink system combining titanium oxide nanoparticles with specific resin particles in an aqueous medium. This composite formulation leverages the high opacity of titanium oxide while using the resin component to provide colloidal stability. The synergistic interaction between the nanoparticle and resin phases enables both jetting performance and long-term stability that neither component could achieve alone.
2Illumination intensity
If white pigment concentration is increased to improve opacity, then print quality is improved, but sedimentation rate increases reducing shelf-life
Solution Approach 1:
Resin particles serve as intermediary structures that surround and stabilize titanium oxide nanoparticles even at high concentrations. The resin-nanoparticle interactions prevent aggregation and sedimentation, allowing the formulation to maintain high opacity through increased pigment loading without sacrificing shelf-life. The resin matrix acts as a protective intermediary that keeps nanoparticles uniformly dispersed.
Solution Approach 2:
The patent optimizes the concentration ratios of titanium oxide nanoparticles to resin particles, and adjusts the size parameters of both components. By controlling the size distribution and concentration parameters within specific ranges, the formulation achieves maximum opacity while maintaining colloidal stability and extended shelf-life, resolving the trade-off between pigment loading and sedimentation resistance.
3Ease of manufacture
If standard aqueous formulations are used, then manufacturing simplicity is maintained, but coating uniformity and water-fastness are insufficient
Solution Approach 1:
The invention develops a composite aqueous formulation combining titanium oxide nanoparticles with specifically selected resin particles. This composite approach enhances coating uniformity and water-fastness through the synergistic interaction between components, while maintaining relative manufacturing simplicity. The resin particles provide film-forming properties and adhesion that improve coating quality without requiring complex processing steps.
Solution Approach 2:
The patent employs resin particles with specific local properties (size, surface characteristics, composition) that are optimized for interaction with titanium oxide nanoparticles. This local optimization of resin particle characteristics enhances coating uniformity and durability in specific application areas, allowing the formulation to achieve superior performance while maintaining ease of manufacture through a relatively simple two-component system.
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 compositions exhibit excellent colloidal stability, extended latency and decap time, high opacity, and improved coating properties, ensuring consistent and high-quality print performance.
Implementation Method 1
exhibit excellent colloidal stability and jetting performance, extended latency and decap time
Implementation Method 2
One obstacle is early sedimentation of white pigment (generally titanium oxide nanoparticles) and lack of long-term colloidal stability
Implementation Method 3
In low viscosity mixtures, such as aqueous inkjet ink compositions
Implementation Method 4
They also exhibit excellent coating properties, including uniform film-formation, wetting and spread
Implementation Method 5
white pigment (generally titanium oxide nanoparticles) have a very high density
Implementation Method 6
high opacity
Implementation Method 7
excellent coating properties, including uniform film-formation, wetting and spread
Implementation Method 8
durability and water-fastness on a variety of substrates
Data Source
AI summary
Aqueous inkjet ink compositions are provided. In an embodiment, such an aqueous inkjet ink composition comprises a solvent system comprising water, a first organic solvent, and a second organic solvent, wherein the second organic solvent is an alkanediol having from 2 to 8 carbon atoms and the second organic solvent is present at an amount of from greater than 0 weight % to about 8 weight %; a white pigment; and resin particles. Methods of making and using the aqueous inkjet ink compositions are also provided.