Crosslinked Core/Shell Polymer Particles for Ink-Jet Bronzing
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Solution Overview
Problem
Ink-jet printing methods using pigments suffer from bronzing, where reflected light exhibits a color different from the inherent pigment color, leading to deterioration in image quality, and existing solutions fail to adequately address this issue in water dispersions and water-based inks.
Innovation Solution
Crosslinked core/shell polymer particles with a pigment weight ratio of 25 to 75 are developed, where the core and shell portions are made of crosslinked polymers, produced through a process involving mixing pigment-containing polymer particles with crosslinkable monomers and hydrophobic monomers, followed by polymerization and crosslinking with a crosslinking agent, to create a stable water dispersion for ink-jet printing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pigment is used as colorant in ink-jet printing, then weather resistance and water resistance are enhanced, but bronzing occurs causing deterioration in image quality
Solution Approach 1:
The invention divides the pigment particle into a core-shell structure where the core contains the pigment and the shell is made of crosslinked polymer. This segmentation isolates the pigment from the external environment while maintaining its optical properties, preventing bronzing while preserving weather and water resistance.
Solution Approach 2:
The invention creates a composite structure combining pigment particles with crosslinked polymer shell. The core/shell configuration integrates the beneficial properties of both components: the pigment provides color and durability, while the crosslinked polymer shell prevents bronzing and maintains structural integrity.
2Object-affected harmful factors
If conventional additives and pigments are added to improve bronzing, then bronzing is reduced, but printed images or characters are adversely affected
Solution Approach 1:
The invention extracts the problematic interaction between pigment and environment by encapsulating the pigment within a crosslinked polymer shell. This removes the need for additional additives that could adversely affect image quality, as the shell itself provides the protective function against bronzing.
Solution Approach 2:
The crosslinked polymer shell acts as an intermediary between the pigment and the external environment. It mediates the interaction by providing a protective barrier that prevents bronzing without requiring additional chemical additives that could compromise image quality.
3Duration of action of stationary object
If core/shell polymer particles are used to improve durability, then durability is enhanced, but bronzing still occurs
Solution Approach 1:
The invention changes the chemical structure of the shell polymer by introducing crosslinking. This parameter change creates a three-dimensional network structure that provides both durability and effective protection against bronzing, overcoming the limitations of conventional non-crosslinked core/shell particles.
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 crosslinked core/shell polymer particles exhibit excellent optical density and gloss while preventing bronzing, maintaining image quality by stabilizing the water dispersion and enhancing print performance.
Implementation Method 1
polymerization and crosslinking with a crosslinking agent, to create a stable water dispersion for ink-jet printing
Implementation Method 2
crosslinked core/shell polymer particles, wherein the polymer particles each include a core portion and a shell portion which are respectively made of a crosslinked polymer
Data Source
AI summary
The present invention relates to crosslinked core/shell polymer particles containing a pigment which are usable in a water-based ink for ink-jet printing and exhibit excellent optical density and gloss and are prevented from suffering from occurrence of bronzing, wherein the polymer particles each include a core portion and a shell portion which are respectively made of a crosslinked polymer, and a weight ratio of the pigment to the pigment-containing crosslinked core/shell polymer particles [(weight of the pigment/weight of the pigment-containing crosslinked core/shell polymer particles)×100] is from 25 to 75. The present invention further relates to a water dispersion and a water-based ink for ink-jet printing which contain the crosslinked core/shell polymer particles and a process for producing crosslinked polymer particles.