Block Copolymer Inkjet Ink for Image Density and Storage Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inkjet inks face a challenge in achieving both high image density and long-term preservation stability, as weakening the adsorption force of the pigment dispersion resin to enhance image density leads to unstable pigment dispersibility and reduced long-term stability.
Innovation Solution
The inkjet ink employs a benzylmethacrylate/methacrylic acid block copolymer as a pigment dispersion resin with specific acid value and mass ratio, ensuring a controlled amount of free resin in the solvent to balance image density and preservation stability, using a hydrophobic polymer block for strong adsorption and a hydrophilic block for stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the adsorption force of the pigment dispersion resin is weakened to enhance image density, then the image density is improved, but the pigment dispersibility becomes unstable and long-term preservation stability is reduced
Solution Approach 1:
The pigment dispersion resin is segmented into two distinct blocks: a hydrophobic polymer block (polystyrene) for strong adsorption to pigment particles, and a hydrophilic polymer block for water solubility and controlled detachment. This segmentation allows the resin to provide strong initial adsorption for high image density while the hydrophilic block enables controlled weakening of adsorption force for stability, resolving the contradiction between image density and preservation stability.
Solution Approach 2:
The invention changes the chemical composition parameters of the pigment dispersion resin by specifying it as a block copolymer with polystyrene content of 20-80 mass% and acid value of 20-200 mg KOH/g. These parameter changes optimize the balance between adsorption strength (for image density) and adsorption weakness (for stability), allowing the system to achieve both high image density and long-term preservation stability simultaneously.
2Stability of the object's composition
If the adsorption force of the pigment dispersion resin is strengthened to improve pigment dispersibility, then the pigment dispersibility is improved, but the image density is reduced
Solution Approach 1:
The block copolymer structure segments the adsorption function into two parts: the hydrophobic polystyrene block provides strong adsorption to pigment particles for excellent dispersibility, while the hydrophilic block provides water solubility and controlled weakening of overall adsorption force. This enables the system to achieve both strong pigment binding (for dispersibility) and controlled detachment (for high image density), resolving the contradiction between these two parameters.
Solution Approach 2:
By changing the chemical structure to a block copolymer with specific composition (polystyrene 20-80 mass%, acid value 20-200 mg KOH/g), the invention optimizes the adsorption strength parameter. The hydrophobic block ensures strong pigment interaction for dispersibility, while the hydrophilic block and acid groups modulate the overall adsorption force to allow sufficient pigment transfer to the substrate for high image density.
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 solution achieves both high image density and long-term preservation stability by maintaining pigment dispersibility and inhibiting permeation into the recording medium, while ensuring rub fastness and color development.
Implementation Method 1
a hydrophobic polymer block formed of benzylmethacrylate
Implementation Method 2
a hydrophilic polymer block formed of methacrylic acid
Implementation Method 3
a mass ratio of a solid in a supernatant liquid obtained by centrifugation
Data Source
AI summary
An inkjet ink includes: a pigment, a block copolymer including a hydrophobic polymer block formed of benzylmethacrylate and a hydrophilic polymer block formed of methacrylic acid, and water. The block copolymer has an acid value of 120 mg KOH/g or more and 220 mg KOH/g or less. A content of the block copolymer is 0.6 mass % or more and 2.6 mass % or less. A mass ratio of the block copolymer to the pigment is 0.12 or more and 0.51 or less. In the inkjet ink, a mass ratio of a solid in a supernatant liquid obtained by centrifugation is 0.5 mass % or more and 3.0 mass % or less.