Ink Composition Conductivity Control via Polyamine-Polyacid Ratio
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Solution Overview
Problem
Existing printing techniques face issues with sedimentation of particulate pigments in ink compositions, leading to poor print quality, and require ink formulations with low conductivity and stable dispersion of pigments over time.
Innovation Solution
An ink composition comprising a particulate pigment, a hydrocarbon vehicle, an organic polyamine, and an organic polyacid, where the ratio of organic polyamine to polyacid ensures conductivity of less than 15 nanosiemens per centimeter, with the pigment being dispersible and coated or encapsulated to maintain stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If ionic dispersants are added to the ink composition to stabilize pigment dispersion, then sedimentation is reduced, but the ink composition becomes highly charged which is unsuitable for certain printing techniques requiring minimal or no charge
Solution Approach 1:
The patent uses non-ionic dispersants as intermediary substances that stabilize pigment dispersion without introducing ionic charges. These dispersants act as mediators between the pigment particles and the ink vehicle, providing steric stabilization through their molecular structure rather than electrostatic repulsion, thus avoiding charge-related incompatibility with printing techniques
Solution Approach 2:
The patent changes the fundamental parameter of dispersant charge from ionic to non-ionic. This parameter change allows the dispersant to maintain pigment suspension stability through non-electrostatic mechanisms (such as steric hindrance), making the ink composition compatible with printing techniques that require minimal or no charge while still preventing sedimentation
2Stability of the object's composition
If conventional ink formulations are used to achieve stable pigment dispersion, then sedimentation is reduced, but the ink conductivity remains too high for electro-photographic printing
Solution Approach 1:
The patent creates a copy or alternative approach to dispersant functionality. Instead of using traditional ionic dispersants, it employs non-ionic dispersants that replicate the pigment-stabilizing function without the harmful ionic conductivity, thus copying the beneficial effect while eliminating the adverse property
Solution Approach 2:
The patent replaces expensive or problematic materials (ionic dispersants that cause high conductivity) with simpler, more suitable alternatives (non-ionic dispersants). This substitution uses readily available non-ionic surfactants and dispersants that provide the necessary stabilization without compromising ink conductivity for electro-photographic printing applications
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 composition achieves stable dispersion of pigments, reducing sedimentation and maintaining print quality by ensuring low conductivity and long-term stability, suitable for various printing techniques such as digital, laser, and electro-photographic printing.
Implementation Method 1
The ratio by weight percent of the organic polyamine to the organic polyacid in the hydrocarbon vehicle is sufficient to render the conductivity of the ink composition to equal to or less than 15 nanosiemens per centimeter
Implementation Method 2
it is important that the particles remain dispersed in the ink medium for extended periods of time. Significant sedimentation can result in poor print quality
Implementation Method 3
Significant sedimentation can result in poor print quality in any of the above techniques
Data Source
AI summary
An ink composition includes a particulate pigment, a hydrocarbon vehicle, an organic polyamine and an organic polyacid. A ratio by weight percent of the organic polyamine to the organic polyacid in the hydrocarbon vehicle is sufficient to render a conductivity of the ink composition to equal to or less than 15 nanosiemens per centimeter. The ink composition is prepared by combining the particulate pigment with a composition that includes the hydrocarbon vehicle, the organic polyamine and the organic polyacid. The combination is subjected to conditions under which the particulate pigment becomes dispersed in the composition.