Keratin-Based Ink Composition for Mild Alkaline De-Inking

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Solution Overview

Problem

Existing dye-based inks require harsh chemical treatments for de-inking, leading to environmental contamination and hinder recyclability of substrates like textiles, paper, and plastics.

Innovation Solution

Ink compositions comprising keratin-based pigments with a particle size of no more than 3000nm, milled to partially unravel the helical structure, allowing easy de-inking with mild alkaline pH water solutions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dye-based inks are used for printing substrates, then colourfastness and lightfastness are achieved, but harsh chemical treatments are required for de-inking leading to environmental contamination

Engineering Contradiction:
ImprovecolourfastnessVSAvoidenvironmental contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the ink by using keratin-based pigments instead of traditional dyes. This fundamental material substitution allows the ink to be removed under mild alkaline conditions (pH 8-12) rather than requiring harsh chemical treatments, thereby eliminating environmental contamination while maintaining colourfastness properties

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The keratin-based pigment particles are designed to be easily removable under mild conditions, effectively treating the ink as a temporary, disposable element that can be cleanly removed from substrates without causing environmental harm, enabling sustainable printing applications

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Reliability

If dye-based inks are used for printing substrates, then colourfastness is achieved, but recyclability of substrates is hindered

Engineering Contradiction:
ImprovecolourfastnessVSAvoidrecyclability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

By changing the chemical composition from traditional dyes to keratin-based pigments with specific particle size characteristics (50-3000nm), the ink becomes removable under mild alkaline conditions, enabling substrates to be recycled through simple de-inking processes without compromising colourfastness during the printing application

Inventive Principle:
Principle #35Parameter changes

3Strength

If traditional dyes are used, then strong ionic binding to fibres is achieved, but extremely harsh chemical treatments including bleaching and oxidation are required for removal

Engineering Contradiction:
Improveionic bindingVSAvoidde-inking process complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent fundamentally changes the binding mechanism from strong ionic bonding to physical adsorption through hydrogen bonding and van der Waals forces. This parameter change in the interaction mechanism allows the keratin-based pigment particles to be easily removed under mild alkaline conditions without requiring complex de-inking processes involving bleaching and oxidation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The keratin-based pigment particles are designed to provide sufficient binding strength during application but be easily removable afterward, effectively serving as a temporary, disposable printing element that simplifies the de-inking process while maintaining the necessary binding characteristics for successful printing

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 keratin-based inks provide superior lightfastness, colourfastness, and recyclability by enabling easy removal from substrates without harsh chemicals, promoting sustainability in packaging and textile industries.

Implementation Method 1

the ink composition of the present invention is an inkjet printing ink

Methodology Applied
Scientific EffectInkjet printing deposition: Deposition (physical)

Implementation Method 2

substrates that have been printed with the ink according to the invention can typically be de-inked using mild alkaline pH water solutions

Methodology Applied
Scientific EffectAlkaline hydrolysis: Hydrolysis

Data Source

PatentEP4526387B1De-inkable inks with high bio-renewable content
Publication Date: 2025.12.24 SUN CHEMICAL BV

AI summary

The present invention relates to a printing ink composition comprising one or more keratin-based pigment(s) and water, wherein the one or more keratin-based pigment(s) has an average particle size of no more than 3000nm.