Ink Jet Ink Composition Stabilizing Pigment Dispersion

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Solution Overview

Problem

Ink jet recording methods using water-based inks with self-dispersible pigments and inorganic oxide particles face issues with dispersion stability and clogging recovery due to the presence of metal ions, leading to degraded stacking and ejection properties.

Innovation Solution

A water-based ink jet ink composition containing self-dispersible pigments, inorganic oxide particles, and a specific poly(ethylene glycol) with selected metal ions (potassium, sodium, or lithium) that stabilizes dispersion and prevents the formation of complex foreign materials, enhancing clogging recovery and intermittent properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If inorganic oxide particles are added to improve stacking property, then stacking property is improved, but clogging recovery property deteriorates

Engineering Contradiction:

Improvestacking propertyVSAvoidclogging recovery property

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

A polyol compound acts as an intermediary substance between the inorganic oxide particles and the self-dispersible pigment. This polyol compound prevents the formation of complex foreign materials by mediating the interactions between particles, thereby maintaining both stacking property improvement and clogging recovery property

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite ink composition containing self-dispersible pigment, inorganic oxide particles, and polyol compound working together. This composite structure allows the inorganic oxide particles to improve stacking while the polyol compound prevents their aggregation with the pigment, maintaining clogging recovery property

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If metal ions are present to stabilize dispersion, then dispersion stability is improved, but clogging recovery property deteriorates

Engineering Contradiction:

Improvedispersion stabilityVSAvoidclogging recovery property

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The polyol compound serves as a mediator that controls the interaction between metal ions and particles. It allows metal ions to stabilize dispersion while preventing them from forming harmful complexes with the self-dispersible pigment, thus maintaining clogging recovery property

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention optimizes the concentration and type of polyol compound to control the chemical environment. By adjusting these parameters, the metal ions can stabilize dispersion without forming complexes that would deteriorate clogging recovery property

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If self-dispersible pigment and inorganic oxide particles are combined, then stacking property is improved, but formation of complex foreign materials occurs

Engineering Contradiction:

Improvestacking propertyVSAvoidcomplex foreign materials

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The polyol compound acts as a protective intermediary between the self-dispersible pigment and inorganic oxide particles. It prevents direct interaction that would form complex foreign materials, while still allowing the inorganic oxide particles to improve stacking property

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention converts the potential harmful interaction between pigment and inorganic oxide particles into a beneficial stable dispersion. The polyol compound transforms what would be complex foreign material formation into a controlled interaction that improves stacking property without harm

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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 ink composition improves stacking and ejection stability by preventing the aggregation of self-dispersible pigments and inorganic oxide particles, maintaining excellent clogging recovery and intermittent properties, even when used with different metal ions in adjacent ink compositions.

Implementation Method 1

a water-based ink jet ink composition, comprising a self-dispersible pigment, inorganic oxide particles, and a poly(ethylene glycol)

Methodology Applied

Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 2

the ink jet ink composition described above contains at least one type of metal ion selected from the group consisting of a potassium ion, a sodium ion, and a lithium ion

Methodology Applied

Scientific EffectIon interaction: Ion Repulsion/Attraction

Data Source

PatentUS20230303871A1Ink Jet Ink Composition, Ink Set, And Recording Method

Publication Date: 2023.09.28 SEIKO EPSON CORP

AI summary

An ink jet ink composition which is a water-based ink, includes a self-dispersible pigment, inorganic oxide particles, and a poly(ethylene glycol) represented by the following general formula (I), and the ink composition contains at least one type of metal ion selected from the group consisting of a potassium ion, a sodium ion, and a lithium ion.HO—(CH2—CH2—O—)n—H (I)In the above formula, n represents an integer of 3 to 9.