Quinacridone Solid Solution Pigment for Yellowish Hue and Stability

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Solution Overview

Problem

Quinacridone pigments used in ink-jet inks face challenges in achieving a yellowish hue and maintaining storage stability, with existing solid solutions either resulting in excessively large primary particles or poor hue uniformity and stability.

Innovation Solution

A quinacridone solid solution pigment comprising C. I. Pigment Violet 19 and C. I. Pigment Red 122, with a specific diffraction peak intensity ratio and crystallite thickness, is developed to achieve a yellowish hue and excellent storage stability, potentially incorporating a quinacridone pigment derivative for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a solid solution of C. I. Pigment Violet 19 and C. I. Pigment Red 202 is used to achieve yellowish hue, then the hue requirement is met, but the primary particles excessively grow leading to poor storage stability

Engineering Contradiction:
ImprovehueVSAvoidstorage stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The invention changes the chemical composition parameter by replacing C. I. Pigment Red 202 with C. I. Pigment Red 122 in the solid solution system. This parameter change achieves the desired yellowish hue while preventing excessive primary particle growth, thereby maintaining storage stability. The specific substitution modifies the crystal lattice parameters and particle formation behavior during ink drying.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite pigment system using a solid solution of C. I. Pigment Violet 19 and C. I. Pigment Red 122. This composite material combines the yellowish hue properties of the red pigment with the stability characteristics of the violet pigment, achieving both color requirements and storage stability without excessive particle growth.

Inventive Principle:
Principle #40Composite materials

2Length of moving object

If a solid solution of C. I. Pigment Violet 19 and C. I. Pigment Red 122 is used to obtain fine primary particles, then smaller particles are achieved, but the hue becomes bluish and storage stability deteriorates

Engineering Contradiction:
Improveprimary particle sizeVSAvoidhue
Core Design Contradiction:
Length of moving objectVSIllumination intensity

Solution Approach 1:

The invention optimizes the composition ratio parameter within the solid solution system of C. I. Pigment Violet 19 and C. I. Pigment Red 122. By controlling the proportion of each pigment component, the invention achieves fine primary particles while preventing the hue from becoming too bluish, thereby balancing particle size reduction with hue maintenance and storage stability.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If existing quinacridone solid solutions are used, then some color properties are achieved, but the relationship between composition and property values (hue, storage stability) is not clear and cannot be specified

Engineering Contradiction:
ImprovehueVSAvoidcomposition-property relationship
Core Design Contradiction:
Illumination intensityVSLoss of information

Solution Approach 1:

The invention establishes a feedback relationship between composition and properties by systematically determining the correlation between solid solution composition ratios and resulting hue/storage stability characteristics. This feedback mechanism enables prediction and control of pigment properties based on composition, allowing specification of optimal ratios for desired performance.

Inventive Principle:
Principle #23Feedback

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 provides a quinacridone pigment with a yellowish and clear hue and superior storage stability in ink-jet inks, ensuring uniform particle size and shape, and improved dispersion stability.

Implementation Method 1

A quinacridone solid solution pigment comprising C. I. Pigment Violet 19 and C. I. Pigment Red 122... a phase in which the atoms at the lattice points of a crystal phase are totally irregularly replaced by atoms of a different type, or a phase in which atoms of a different type are introduced into a crystal phase so as to be statistically distributed in the space of lattice

Methodology Applied
Scientific EffectSolid solution formation: Crystallisation

Implementation Method 2

the ratio of a diffraction peak intensity at a diffraction angle 2θ of 14.8±0.2° to a diffraction peak intensity at a diffraction angle 2θ of 11.9±0.2° is 1.20 or less, as measured by X-ray diffractometry

Methodology Applied
Scientific EffectX-ray diffraction: X-Ray

Implementation Method 3

The presence of a solid solution can be found by, for example, the measurement, of a crystal X-ray diffraction spectrum from a result that a new peak appears at a diffraction angle at which no peak is present

Methodology Applied
Scientific EffectBragg diffraction: Bragg Diffraction

Data Source

PatentUS12104063B2Solid solution of quinacridone and ink composition containing same
Publication Date: 2024.10.01 DIC CORP

AI summary

An object to be achieved by the present, invention is to provide a quinacridone pigment having hue that is yellowish and clear and having excellent storage stability, wherein the quinacridone pigment can be advantageously used in an ink-jet ink and the like. Provided is a quinacridone solid solution pigment comprising at least C. I. Pigment Violet 19 and C. I. Pigment Red 122, wherein the ratio of a diffraction peak intensity at a diffraction angle 2θ of 14.8±0.2° to a diffraction peak intensity at a diffraction angle 2θ of 11.9±0.2° is 1.20 or less, as measured by X-ray diffractometry with respect to the quinacridone solid solution pigment.