Solvent-Based Inkjet Inks With Surface-Modified Pigments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Thermal inkjet printheads are limited to printing on porous and semi-porous substrates due to the use of water-based ink formulations, restricting their application to only SOHO markets, while piezo printheads offer wider ink formulation flexibility and can print on non-porous substrates.
Innovation Solution
Development of solvent-based ink compositions for thermal inkjet printheads that include surface-modified pigments and specific solvent combinations, such as N-methyl-2-pyrrolidinone and ethanol, allowing for effective ink ejection and adhesion to non-porous substrates like vinyl and polyester without the need for high polymer concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If water-based ink formulations are used in thermal inkjet printheads, then rapid bubble formation and high-speed printing are achieved, but the printheads are limited to printing on porous and semi-porous substrates only
Solution Approach 1:
The patent changes the chemical composition parameters of the ink formulation from water-based to solvent-based (using compounds like N-methyl-2-pyrrolidinone, cyclohexanone, or esters). This parameter change enables the ink to be ejected and adhere to non-porous substrates while maintaining compatibility with thermal bubble-forming printheads, thus expanding substrate compatibility without sacrificing printing speed
Solution Approach 2:
The patent uses composite ink formulations combining specific solvents (NMP, cyclohexanone, esters) with surface-modified pigments and optional polymers. This composite approach creates an ink system that achieves both rapid bubble formation for high-speed printing and effective adhesion to diverse substrates including non-porous materials
2Adaptability or versatility
If solvent-based ink formulations are used in thermal inkjet printheads, then printing on non-porous substrates is enabled, but polymer kogation on heater elements and reduced ink latency occur
Solution Approach 1:
The patent carefully controls polymer concentration parameters, using low levels (0.1-10% by weight) or eliminating polymers entirely in solvent-based formulations. This parameter control reduces polymer kogation on heater elements and maintains ink latency, while still achieving effective printing on non-porous substrates through the solvent system
Solution Approach 2:
The patent uses surface-modified pigments as intermediaries to facilitate ink adhesion to non-porous substrates. These modified pigments provide the necessary surface properties for bonding without requiring high polymer concentrations, thus preventing polymer-related reliability issues while maintaining substrate compatibility
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
Enables thermal inkjet printheads to print on a wider range of substrates, including non-porous media, enhancing their competitiveness with piezo printers by maintaining high-resolution and high-speed printing capabilities while minimizing polymer buildup and cost.
Implementation Method 1
Thermal bubble-forming inkjet printheads function by generating a certain amount of heat in the printing fluid contained in a nozzle chamber
Implementation Method 2
This heat causes a bubble to form which eventually collapses as the fluid is forced through a nozzle
Implementation Method 3
Solvent-based inkjet inks comprising pigments, as used in piezo printheads, contain high concentrations of polymer to help form stable dispersions of appropriate particle size
Data Source
AI summary
A solvent-based ink composition for a thermal inkjet printhead comprises a surface-modified pigment. The ink composition comprises:(a) 10-80 wt. % of a compound of formula (A);wherein:R1 is C1-6 alkyl; andeach of R2, R3 and R4 is independently selected from H, C1-6 alkyl, halogen, OH, and C1-6 alkoxy;(b) 10-80 wt. % of a C1-6 alcohol; and(c) 0.01-25 wt. % of the surface-modified pigment.