Oil-Based Inkjet Ink Formulation for Nozzle Plate Protection
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Solution Overview
Problem
Oil-based inkjet inks face challenges with storage stability and wiping resistance, particularly as pigment concentration increases, leading to nozzle plate damage during cleaning due to the high affinity of acidic carbon blacks with the nozzle plate.
Innovation Solution
An oil-based inkjet ink formulation containing acidic carbon black with a pH of 2 to 6, a modified silicone oil with a surface tension of not more than 27 mN/m, and a pigment dispersant, which improves storage stability and wiping resistance by enhancing dispersibility and protecting the nozzle plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the pigment concentration in the ink is increased to achieve high image density, then the image density is improved, but the storage stability of the ink deteriorates
Solution Approach 1:
A dispersant is introduced as an intermediary substance between the pigment particles and the ink vehicle. The dispersant adsorbs onto the pigment surface, providing steric or electrostatic repulsion that prevents pigment aggregation and maintains ink stability even at high pigment concentrations required for high image density
Solution Approach 2:
The pH of the ink is adjusted to specific ranges (typically acidic pH between 3-6) to optimize the surface charge of the pigment particles and enhance their dispersion stability. This parameter change allows higher pigment concentrations to be maintained without sacrificing storage stability
2Stability of the object's composition
If acidic carbon black is used to achieve favorable storage stability, then the storage stability is improved, but the wiping resistance of the nozzle plate deteriorates due to adhesion
Solution Approach 1:
The dispersant acts as a protective intermediary layer between the acidic carbon black particles and the nozzle plate surface. This layer reduces the direct adhesion interaction, allowing the ink to maintain storage stability with acidic pigment while the dispersant coating prevents the pigment from bonding strongly to the nozzle plate during cleaning operations
Solution Approach 2:
The acidic properties of the carbon black, which normally cause strong adhesion to the nozzle plate and reduce wiping resistance, are converted into a benefit through the dispersant. The dispersant utilizes the acidic surface groups to create stable electrostatic or steric barriers, transforming the harmful adhesion into beneficial stabilization while preventing nozzle plate damage
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 excellent storage stability and improved wiping resistance, preventing nozzle plate damage during cleaning, even at higher pigment concentrations.
Implementation Method 1
the non-aqueous solvent contains a modified silicone oil having a surface tension of not more than 27 mN/m
Data Source
AI summary
An oil-based inkjet ink is disclosed, the oil-based inkjet ink containing a pigment, a pigment dispersant and a non-aqueous solvent, wherein the pigment contains an acidic carbon black having a pH of 2 to 6, the non-aqueous solvent contains a modified silicone oil having a surface tension of not more than 27 mN/m, and an amount of the modified silicone oil, relative to a total mass of the oil-based inkjet ink, is at least 15% by mass but not more than 80% by mass.