Inkjet processing fluid, and ink set and printing method using same

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Solution Overview

Problem

Existing inkjet processing solutions for textile printing face issues such as corrosion of metal heads due to high halogen ion concentrations and yellowing of the recording medium, along with degradation of fabric texture due to binder resin penetration.

Innovation Solution

An inkjet processing solution with a halogen ion concentration of 5 kg/m3 or less and a pH of 7 to 9.5, containing a cationic polymer and lactic acid, which reacts with ink pigments to enhance chromogenic properties while suppressing corrosion and yellowing, and uses an anionic pigment to prevent binder resin penetration in fabrics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a processing solution containing reactive fine particles is used to enhance color material formation, then chromogenic property is improved, but halogen ion concentration increases causing corrosion of metal inkjet heads

Engineering Contradiction:
Improvechromogenic propertyVSAvoidcorrosion of metal inkjet head
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes halogen ions from the processing solution through ion exchange treatment, separating the harmful ions from the beneficial reactive fine particles. This allows the solution to maintain its chromogenic functionality while eliminating the corrosive elements that damage metal inkjet heads.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an ion exchange resin as an intermediary substance that mediates between the reactive fine particles and the halogen ions. The resin selectively binds and removes halogen ions from the solution, allowing the reactive particles to remain active for color formation without the corrosive side effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If halogen ion concentration is reduced to prevent corrosion, then reliability of inkjet head is improved, but dispersion stability of reactive components deteriorates

Engineering Contradiction:
Improveinkjet head durabilityVSAvoiddispersion stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The ion exchange resin acts as an intermediary that selectively removes halogen ions while preserving the reactive fine particles. This mediator enables the system to achieve both low halogen ion concentration for head durability and maintained dispersion stability through the preserved reactive particles.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the ionic composition parameters of the processing solution by selectively removing halogen ions through ion exchange. This parameter change allows the solution to maintain adequate dispersion stability through controlled ion balance while achieving the low halogen ion concentration needed for inkjet head durability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If cationic polymer is added to react with color material to improve chromogenic property, then image density is enhanced, but yellowing of recording medium occurs due to high halogen ion concentration

Engineering Contradiction:
Improveimage densityVSAvoidyellowing of recording medium
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts halogen ions from the processing solution through ion exchange treatment, removing the cause of yellowing while preserving the cationic polymer's ability to react with color materials. This extraction allows high image density to be achieved without the harmful yellowing side effect.

Inventive Principle:
Principle #2Taking out (Extraction)

4Stability of the object's composition

If processing solution with high halogen ion concentration is used to ensure reactive particle stability, then dispersion stability is maintained, but corrosion of metal components increases

Engineering Contradiction:
Improvedispersion stabilityVSAvoidcorrosion of metal components
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The ion exchange resin serves as an intermediary that selectively binds halogen ions, allowing the processing solution to maintain dispersion stability through controlled ionic environment while the resin captures the corrosive halogen ions before they can damage metal components.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively prevents corrosion of inkjet heads, reduces yellowing of textiles, and maintains fabric texture by ensuring pigments remain on the surface, achieving excellent image density and fabric quality.

Implementation Method 1

a cationic polymer... which reacts with ink pigments to enhance chromogenic properties

Methodology Applied
Scientific EffectElectrostatic attraction: Ion Repulsion/Attraction

Implementation Method 2

a pH of 7 to 9.5, containing a cationic polymer and lactic acid

Methodology Applied
Scientific EffectpH buffering:

Implementation Method 3

a halogen ion concentration of 5 kg/m3 or less... suppressing corrosion

Methodology Applied
Scientific EffectCorrosion resistance:

Implementation Method 4

ensuring pigments remain on the surface... uses an anionic pigment to prevent binder resin penetration in fabrics

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP4241994B1Inkjet processing fluid, and ink set and printing method using same
Publication Date: 2026.03.25 KYOCERA CORP
  • EP4241994B1 patent drawingFigure 1
  • EP4241994B1 patent drawing

AI summary

An aspect of the present invention relates to an inkjet processing solution including a cationic polymer and lactic acid, where halogen ion concentration is 5 g/L or less and pH is 7 to 9.5.