Inkjet Ink Cation Mixture Extends Decap Time
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Solution Overview
Problem
Current pigmented inkjet inks face a tradeoff between decap time and other essential properties, with a need for longer decap time while maintaining image quality and stability.
Innovation Solution
An aqueous inkjet ink formulation comprising a pigment stabilized with an anionic dispersant, featuring a specific molar ratio of lithium and one or more of sodium, potassium, rubidium, and cesium cations, along with a combination of humectants like 2-pyrrolidone, ethylene glycol, and triethylene glycol, to enhance latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If smaller drops are fired to increase image resolution, then image quality is improved, but decap time decreases due to faster evaporation
Solution Approach 1:
The patent changes the chemical composition parameters of the ink by introducing a specific cation mixture (lithium with sodium, potassium, rubidium, and/or cesium in controlled molar ratios) to modify the evaporation characteristics of the volatile vehicle components, thereby extending decap time without affecting drop size or image resolution
Solution Approach 2:
The patent introduces humectants (such as ethylene glycol, diethylene glycol, triethylene glycol, or 2-pyrrolidone) as intermediary substances that mediate between the volatile vehicle components and the environment, reducing evaporation rate and extending the time the printhead can remain uncapped while maintaining proper droplet ejection
2Stability of the object's composition
If pigment particles are stabilized with dispersing agents, then dispersion stability is improved, but ink formulation complexity increases
Solution Approach 1:
The patent modifies the chemical parameters of the dispersing system by specifying particular cation compositions and ratios, which optimize the interaction between anionic dispersants and pigment particles, achieving enhanced dispersion stability without requiring complex polymeric dispersants or multiple additives
Solution Approach 2:
The patent applies local quality by focusing the stabilization mechanism at the pigment particle surface through specific cation-anionic interactions, where the cation mixture works in conjunction with anionic dispersants to provide targeted stabilization exactly where needed, rather than using complex bulk formulation approaches
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 formulation achieves significantly extended decap time without compromising other print properties, such as image quality and stability, by optimizing the cationic species ratio and humectant composition.
Implementation Method 1
pigment stabilized with anionic dispersant
Implementation Method 2
The increased surface area to volume to the smaller drops allows faster evaporation of volatile vehicle components at the nozzle face
Data Source
AI summary
The present invention pertains to an aqueous inkjet ink comprising pigment stabilized to dispersion with anionic dispersant, wherein cations present in the ink comprise a mixture, in a certain molar ratio, of lithium and one or more of sodium, potassium, rubidium and/or cesium. The inks exhibit greatly extended latency.