Aqueous Inkjet Ink Composition Without Water-Soluble Resins

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Solution Overview

Problem

Existing aqueous inkjet ink compositions face issues with viscosity tuning, flocculation, and reduced water-fastness due to the use of water-soluble resins, which interfere with electrostatic stability and image quality.

Innovation Solution

Forming high viscosity latexes using unique latex formulations and processing steps, incorporating specific monomers like styrene and alkyl acrylates, along with acidic, hydrophilic, and difunctional monomers, and reactive surfactants, without water-soluble resins, to achieve mechanically robust resin particles that form high-quality films.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If water-soluble resins are added to tune viscosity and facilitate thin film formation, then film formation is improved, but flocculation and aggregation of resin particles occur and electrostatic stability is interfered with

Engineering Contradiction:
Improvefilm formation qualityVSAvoidelectrostatic stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent removes water-soluble resins from the inkjet ink composition entirely, extracting the problematic component that caused flocculation and aggregation. Instead, the formulation relies on latex particles with specific glass transition temperatures and viscosity characteristics to achieve both film formation and stability without the harmful additive.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the physical parameters of the latex particles by selecting materials with specific glass transition temperatures (Tg) and viscosity ranges. By controlling particle size, Tg, and viscosity, the formulation achieves proper film formation without requiring water-soluble resins, thereby maintaining electrostatic stability.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If water-soluble resins are added to tune viscosity, then viscosity control is improved, but water-fastness of printed images is reduced

Engineering Contradiction:
Improveviscosity controlVSAvoidwater-fastness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts water-soluble resins from the formulation, eliminating the source of water-fastness problems. Viscosity control is achieved instead through the inherent properties of the latex particles and other ink components, preventing the resin-induced reduction in water resistance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent controls viscosity through parameters of the latex particles themselves (size, Tg, viscosity) and other ink components rather than adding water-soluble resins. This parameter change approach maintains both viscosity control and water-fastness by avoiding the harmful interaction between water-soluble resins and the printed image.

Inventive Principle:
Principle #35Parameter changes

3Shape

If conventional latex formulations are used, then resin particles form as small rigid spheres, but additional water-soluble resins are required to achieve desired viscosity and film properties

Engineering Contradiction:
Improveresin particle morphologyVSAvoidcomposition complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent removes water-soluble resins from the composition, simplifying the formulation. The desired viscosity and film properties are achieved through optimized latex particle characteristics rather than additional additives, reducing composition complexity while maintaining conventional spherical particle morphology.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The latex particles are designed to perform multiple functions: providing the desired viscosity, forming quality films, and maintaining stability without requiring separate water-soluble resin additives. This multi-functionality reduces the overall composition complexity while achieving the desired particle morphology.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 resulting latexes and ink compositions exhibit excellent rub/mar-resistance and water-fastness, with high viscosities and glass transition temperatures, enabling superior film formation without additional resins.

Implementation Method 1

The resin particles of the latex act as a binder which help form a water-impenetrable, polymeric film that protects printed images.

Methodology Applied
Scientific EffectPolymer film formation: Binder

Implementation Method 2

water-soluble resins can induce flocculation and aggregation of resin particles as well as interfere with their electrostatic stability

Methodology Applied
Scientific EffectElectrostatic stability: Electrostatics

Data Source

PatentEP4001367B1Aqueous inkjet ink compositions made from high viscosity latexes
Publication Date: 2026.01.07 XEROX CORP
  • EP4001367B1 patent drawingFigure 1
  • EP4001367B1 patent drawingFigure 2

AI summary

Aqueous inkjet ink compositions are provided. In an embodiment, such an aqueous inkjet ink composition comprises water; resin particles; a colorant; and optionally, a wax. The resin particles comprise a polymerization product of reactants comprising a monomer, an acidic monomer, a hydrophilic monomer, a difunctional monomer, and a reactive surfactant. The acidic monomer, the hydrophilic monomer, and the difunctional monomer may be present at an amount in a range of from about 10 weight% to about 30 weight% in the resin particles. Methods of forming and using the aqueous inkjet ink compositions are also provided.