Iron-Modified Carbon Black Composition for Ink Dispersion Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Carbon blacks used in inks and other applications suffer from insufficient dispersion stability, leading to increased viscosity and poor printability due to strong interparticle attractive forces, which results in precipitation during storage and renders the ink unusable.

Innovation Solution

Incorporating a specified amount of iron element on the surface of carbon black particles, treated with iron oxide, to enhance dispersion stability through ionic and hydrogen bonding interactions with polymers, thereby forming a stable dispersion network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If carbon blacks with smaller particle sizes are used to increase degree of blackness and coloring power, then coloring performance is improved, but dispersion stability deteriorates due to increased surface area and strong interparticle attractive forces

Engineering Contradiction:
Improvedegree of blacknessVSAvoiddispersion stability
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The invention changes the chemical composition parameter of carbon black by incorporating specific metal elements (Fe: 0.003-0.03 atomic%, Ni: 0.003-0.03 atomic%, Cr: 0.003-0.03 atomic%) to modify surface properties. This compositional change reduces interparticle attractive forces while maintaining small particle size (average 20-100 nm), thereby achieving both high coloring power and improved dispersion stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by combining carbon black particles with metal elements on their surface. This composite approach allows the carbon black to maintain its core coloring function while the metal component modifies surface chemistry to reduce aggregation, effectively resolving the contradiction between particle size and dispersion stability.

Inventive Principle:
Principle #40Composite materials

2Device complexity

If carbon blacks are dispersed in solvent alone, then simplicity of formulation is maintained, but dispersion stability deteriorates as aggregates rapidly reform agglomerates

Engineering Contradiction:
Improveformulation complexityVSAvoiddispersion stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The modified carbon black particles are self-stabilizing due to the metal elements on their surface that inherently reduce interparticle attractive forces. This eliminates the need for additional dispersing agents or complex polymer systems, allowing stable dispersion to be achieved with simple solvent formulation alone.

Inventive Principle:
Principle #25Self-service

3Duration of action of stationary object

If carbon black precipitates during storage, then dispersion stability has been lost, but this renders the ink unusable for printing applications

Engineering Contradiction:
Improvestorage stabilityVSAvoidprintability
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The metal elements are incorporated into the carbon black structure during manufacturing, performing preliminary modification of surface properties before the ink is even formulated. This pre-engineered surface chemistry prevents aggregation and precipitation during storage, ensuring long-term stability and reliable printability without requiring additional stabilizing measures.

Inventive Principle:
Principle #10Preliminary action

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 modified carbon black exhibits excellent dispersion stability and low viscosity, making it suitable for inks and various applications such as printing, coatings, and cosmetics, with improved printability and storage properties.

Implementation Method 1

enhance dispersion stability through ionic and hydrogen bonding interactions with polymers

Methodology Applied
Scientific EffectIonic bonding: Chemical Bonding

Implementation Method 2

enhance dispersion stability through ionic and hydrogen bonding interactions with polymers

Methodology Applied
Scientific EffectHydrogen bonding: Chemical Bonding

Implementation Method 3

it is necessary to adsorb the polymer onto the carbon black via intermolecular interaction

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 4

A type of intermolecular interaction is van der Waals forces. The van der Waals forces are forces that can act even between neutrally charged molecules.

Methodology Applied
Scientific EffectIntermolecular interaction: Van der Waals Force

Data Source

PatentUS20240084146A1Carbon black, ink, coating composition, coloring agent for plastics, colored molded article, coloring agent for stationery and writing instruments, textile printing agent, toner, dispersion or resist for color filters, and cosmetic composition
Publication Date: 2024.03.14 DIC CORP

AI summary

An object of the present invention is to provide a carbon black, an ink, and the like having excellent dispersion stability. A carbon black of the present invention includes iron element in an amount of 0.01 to 2.00 parts by mass per 100 parts by mass of the carbon black. Preferably, a ratio of Fe/C is 0.001 to 0.010, where Fe is a concentration in atomic % of the iron element on a surface of particles of the carbon black, and C is a concentration in atomic % of elemental carbon on the surface of the particles of the carbon black, as determined by X-ray photoelectron spectroscopy.