Ink Jet Recording Method Nitrogen-Containing Solvent Bubble Control
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Solution Overview
Problem
Ink jet recording methods face challenges with ink jet heads having step nozzles, where bubbles can get entrapped, leading to discharging reliability issues and poor image quality on non-ink absorbable or low ink absorbable recording media, due to the use of water-based inks and high-boiling solvents.
Innovation Solution
An ink jet recording method using an ink composition with a nitrogen-containing solvent, where the difference in solubility parameter (SP value) between the solvent and resin is within 5, and the solvent content is between 0.1 to 0.4 parts by mass with respect to water, along with a total organic solvent content of 15% or more, to enhance film forming properties and discharging reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high boiling point solvent is added to the water-based ink to prevent clogging of the ink jet head, then discharging reliability is improved, but driability of the ink attached to the recording medium is deteriorated
Solution Approach 1:
The invention changes the chemical composition parameters of the solvent system by specifying precise ratios of nitrogen-containing solvent (0.1-0.4 parts by mass per part of water) and limiting high boiling point solvents to less than 5% by mass. This parameter optimization allows the ink to maintain discharging reliability while improving driability on non-ink absorbable media.
Solution Approach 2:
The invention uses a composite solvent system combining nitrogen-containing solvent with water and controlled amounts of other solvents. This composite approach leverages the bubble-suppressing properties of nitrogen-containing solvents while controlling the overall composition to prevent resin dissolution and welding in the ink jet head.
2Manufacturing precision
If the nozzle is formed by etching to increase nozzle resolution, then recording resolution is improved, but bubbles are likely to be entrapped in the nozzle hole, deteriorating discharging reliability
Solution Approach 1:
The nitrogen-containing solvent acts as an intermediary substance that mediates between the etched nozzle structure and the ink flow. It suppresses bubble generation at the step structure created by etching, allowing high-resolution nozzles to function reliably without bubble entrapment issues.
3Object-affected harmful factors
If water-based resin ink composition is used for environmental and safety reasons, then global environment and human safety are improved, but compatibility between discharging reliability and film forming properties is problematic
Solution Approach 1:
The invention optimizes the chemical parameters of the water-based ink by precisely controlling the nitrogen-containing solvent content (0.1-0.4 parts by mass per part of water) and limiting high boiling point solvents to less than 5% by mass. This parameter optimization enables the water-based ink to simultaneously achieve reliable discharging and good film forming properties on non-ink absorbable media.
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 method achieves excellent abrasion resistance and discharging reliability by improving ink film formation and reducing nozzle clogging, even on non-ink absorbable or low ink absorbable media, allowing for extended continuous printing without cleaning.
Implementation Method 1
when the nitrogen-containing solvent is contained in the ink, the resin contained in the water-based ink is dissolved on the recording medium so as to obtain the film forming properties of the ink coated film
Implementation Method 2
in a case of the ink in which a high-boiling point solvent such as glycerin is not contained, water easily evaporates, and thus the dissolution and welding of the resin are likely to occur
Implementation Method 3
When the step structure is formed in the nozzle, bubbles are likely to be entrapped in a nozzle hole at the time of discharging the ink
Data Source
AI summary
An ink jet recording method includes attaching an ink composition, with which a pressure chamber of an ink jet head is filled, to a recording medium by discharging the ink composition via a nozzle port, in which the ink jet head includes a step between the pressure chamber and the nozzle port, the ink composition contains water, a resin, and an organic solvent including at least a nitrogen-containing solvent, and the organic solvent includes an organic solvent, in which a difference in a SP value between the organic solvent and the resin is within 5, in a range of 0.1 part by mass to 0.4 parts by mass with respect to 1 part by mass of water, and does not include an organic solvent which has a standard boiling point of equal to higher than 280° C. and the content of more than 5% by mass in the ink composition.