Stabilizing Aqueous Inkjet Inks via Crosslinkable Anionic Resins

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Aqueous inkjet ink compositions face issues with aggregation of solids, leading to jetting instability and nozzle clogging, exacerbated by latexes that interfere with colorant dispersibility and increase solid content.

Innovation Solution

Incorporating resin particles polymerized from hydrophobic and anionic monomers, including crosslinkable anionic monomers, into aqueous inkjet ink compositions to enhance stability by preventing pigment particle aggregation through electrostatic and steric repulsion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If latexes are added to aqueous inkjet ink compositions to bind colorants and protect printed images, then binding and protection functions are improved, but aggregation of solids occurs leading to jetting instability and nozzle clogging

Engineering Contradiction:

Improvebinding and protection functionVSAvoidsolid content stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical composition parameters of the latex by incorporating specific ratios of hydrophobic monomers (20-80 wt%) and anionic monomers (20-80 wt%), including crosslinkable anionic monomers (1-50 wt%). This parameter optimization prevents aggregation while maintaining binding function, resolving the contradiction between reliability and composition stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite latex system combining multiple monomer types (hydrophobic, anionic, and crosslinkable anionic monomers) to achieve both binding capability and aggregation prevention. The crosslinkable anionic monomers form a network structure that stabilizes the composition while maintaining the necessary binding properties.

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If dispersants are used in aqueous inkjet ink compositions to disperse colorants, then colorant dispersibility is improved, but humectants interfere with these dispersants leading to aggregation

Engineering Contradiction:

Improvecolorant dispersibilityVSAvoidinterference from humectants

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent uses the specially formulated latex with crosslinkable anionic monomers as an intermediary that mediates between the colorants and humectants. The latex structure with its specific monomer composition prevents humectant interference while maintaining colorant dispersibility, effectively isolating the harmful interaction.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

By optimizing the monomer composition parameters, particularly the inclusion of crosslinkable anionic monomers at 1-50 wt%, the patent creates a latex that resists interference from humectants. This parameter change allows the system to maintain colorant dispersibility even in the presence of interfering humectant components.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If latexes are added to aqueous inkjet ink compositions to bind colorants, then binding function is improved, but the latexes increase the solid content leading to jetting instability and nozzle clogging

Engineering Contradiction:

Improvebinding functionVSAvoidsolid content

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent optimizes the solid content parameter by controlling the monomer composition and crosslinking degree. The specific ratio of hydrophobic (20-80 wt%) and anionic (20-80 wt%) monomers, with crosslinkable anionic monomers (1-50 wt%), creates a latex that provides adequate binding function with minimized solid content, preventing jetting instability and nozzle clogging.

Inventive Principle:

Principle #35Parameter changes

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 use of resin particles with a high content of crosslinkable anionic monomers results in highly stable inkjet ink compositions, maintaining minimal particle size changes over extended storage and challenging conditions, even with high humectant amounts, thus preventing agglomeration and ensuring stable jetting performance.

Implementation Method 1

the resin particles prevent pigment particle aggregation through electrostatic and steric repulsion

Methodology Applied

Scientific EffectElectrostatic repulsion: Ion Repulsion/Attraction

Implementation Method 2

the resin particles prevent pigment particle aggregation through electrostatic and steric repulsion

Methodology Applied

Scientific EffectSteric repulsion:

Data Source

PatentUS20240400846A1Stabilizing aqueous inkjet ink compositions

Publication Date: 2024.12.05 XEROX CORP

AI summary

Aqueous inkjet ink compositions are provided which comprise water, a co-medium, pigment particles, and resin particles, wherein the resin particles comprise a polymerization product of reactants comprising: one or more types of hydrophobic monomers; and one or more types of anionic monomers comprising one or more types of crosslinkable anionic monomers.