Ink-Jet Printing Ink Formulation for High Optical Density
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Solution Overview
Problem
Current ink-jet printing technologies face challenges in achieving high optical density and neutral shades, particularly in single-pass systems, due to issues with nozzle blockages and color compromise when using reactive dyes, as existing inks become viscous or dry in nozzles, leading to unreliable jetting and compromised black coloration.
Innovation Solution
A black ink-jet printing ink formulation comprising specific dyes (C.I. Reactive Black 39, Reactive Brown 11, Reactive Yellow 95, Reactive Orange 12, and Reactive Orange 13) with carefully selected solvents and additives, such as ethylene glycol, urea, and a buffer, which maintains optimal viscosity and pH, ensuring reliable jetting and retention of black coloration through steam treatment and washing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If dye loading is increased to achieve high optical density, then the optical density improves, but the ink becomes very viscous or dries in nozzles resulting in blocked nozzles and jet straightness issues
Solution Approach 1:
The patent applies parameter changes by carefully adjusting the dye loading concentration and ink formulation parameters (solvent composition, pH, viscosity modifiers) to achieve high optical density while maintaining jetting reliability. The ink is formulated with specific dye concentrations that optimize both color strength and flow properties for reliable nozzle operation.
2Illumination intensity
If dye loading is increased to achieve high optical density, then the optical density improves, but jetting reliability deteriorates due to ink becoming very viscous or drying in nozzles
Solution Approach 1:
The patent optimizes ink formulation parameters including dye concentration, solvent composition, pH levels, and viscosity modifiers to simultaneously achieve high optical density and maintain jetting reliability for productive single-pass printing operations.
Solution Approach 2:
The ink is formulated as a composite material system combining multiple reactive dyes (C.I. Reactive Black 39, C.I. Reactive Brown 11, C.I. Reactive Yellow 95, C.I. Reactive Orange 12, C.I. Reactive Orange 13) with carefully selected solvents and additives to achieve both high optical density and reliable jetting performance.
3Illumination intensity
If navy blue reactive dye is shaded by adding smaller amounts of other colored reactive dyes to create black ink, then the black coloration is achieved, but the shading properties of minor components are lost at low optical density and the true black coloration is compromised
Solution Approach 1:
The patent uses a composite material approach by formulating black ink as a mixture of multiple reactive dyes (C.I. Reactive Black 39, C.I. Reactive Brown 11, C.I. Reactive Yellow 95, C.I. Reactive Orange 12, C.I. Reactive Orange 13) in specific proportions. This composite formulation maintains color neutrality and true black coloration even at low optical densities, avoiding the shading issues associated with conventional navy blue-based black inks.
Data Source
AI summary
A black ink-jet printing ink comprising:a) from 9 to 11.5 parts of C.I. Reactive Black 39;b) from 5 to 7.5 parts of C.I. Reactive Brown 11 and/or C.I. Reactive Yellow 95;c) from 2.5 to 4 parts of C.I. Reactive Orange 12 and/or C.I. Reactive Orange 13;d) from 0.1 to 10 parts of a buffer;e) from 15 to 30 parts of ethylene glycol;f) from 0 to 10 parts of a water miscible solvent;g) from 0.01 to 2.5 parts of a non-ionic surfactant;h) from 4 to 14 parts of urea;i) from 0 to 5 parts of biocide; andj) the balance to 100 parts water. Also an ink-jet printing process, a multicolour ink-set and printed substrates.