Aqueous Ink Composition for Stable High-Speed Inkjet Ejection
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Solution Overview
Problem
Existing ink-jet printing technologies face challenges in achieving high productivity and ejection stability, particularly in industrial applications, with issues arising from intermittent ejection and continuous ejection properties during high-speed printing and restarts.
Innovation Solution
A water-based ink formulation containing a pigment, a carboxy group-containing polymer, a specific organic solvent with a relative permittivity of 27-38, and a combination of acetylene glycols with varying ethoxylation degrees, optimized to enhance ejection stability and continuous ejection properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional water-based inks are used for high-speed printing, then productivity increases, but ejection stability deteriorates during intermittent ejection and restarts
Solution Approach 1:
The patent applies parameter changes by carefully controlling the water content (30-70% by mass) and organic solvent content (30-65% by mass) in the ink formulation. This specific compositional parameter range ensures the ink maintains appropriate viscosity and surface tension for both high-speed continuous ejection and stable restart performance, resolving the contradiction between productivity and ejection stability
Solution Approach 2:
The patent uses a composite material approach by combining water and organic solvents in a specific ratio range. This composite solvent system leverages the complementary properties of water (cost-effectiveness, safety) and organic solvents (volatility control, ejection performance) to achieve both high productivity and reliable ejection stability during intermittent operation and restarts
2Productivity
If ink formulation is optimized for continuous ejection, then productivity improves, but performance after prolonged interruptions deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the organic solvent content (30-65% by mass) and water content (30-70% by mass) to achieve a balanced formulation. This parameter optimization ensures the ink maintains stable rheological properties that support both continuous high-speed ejection and reliable performance after prolonged interruptions, resolving the contradiction between productivity and restart performance
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 exhibits improved ejection stability and continuous ejection properties, ensuring reliable printing performance even after prolonged interruptions and at high speeds.
Implementation Method 1
a specific organic solvent with a relative permittivity of 27-38
Implementation Method 2
a combination of acetylene glycols with varying ethoxylation degrees
Data Source
AI summary
The present invention relates to [1] a water-based ink for ink-jet printing, containing a pigment (A), a carboxy group-containing polymer (B), an organic solvent (C), an acetylene glycol compound (D) and water, in which the organic solvent (C) contains an organic solvent (c-1) having a relative permittivity (εr) of not less than 27 and not more than 38 as measured at 23°C; a content of the organic solvent (c-1) in the water-based ink is not less than 33% by mass and not more than 55% by mass; a mass ratio of the organic solvent (c-1) to the organic solvent (C) [organic solvent (c-1)/organic solvent (C)] is not less than 0.75; and the acetylene glycol compound (D) contains an acetylene glycol (d-1) having an average molar number of addition of ethyleneoxide of not less than 4 mol and not more than 15 mol, and an acetylene glycol (d-2) having an average molar number of addition of ethyleneoxide of less than 4 mol.