Quinacridone Solid Solution Pigment Inkjet Chroma Control
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Solution Overview
Problem
Conventional quinacridone solid solution pigments lack high chroma and bluish hue, and struggle to control particle diameters for inkjet ink applications, leading to insufficient color performance and stability.
Innovation Solution
A method involving a co-cyclization reaction of diarylaminoterephthalic acid and dialkylarylaminoterephthalic acid in polyphosphoric acid to produce a water-containing crude quinacridone solid solution, followed by drying to reduce water content and heating in a solvent to control particle diameters, resulting in a quinacridone solid solution pigment with high chroma and bluish hue suitable for inkjet inks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional quinacridone solid solution pigments are used, then production is straightforward, but chroma and bluish hue are insufficient
Solution Approach 1:
The patent applies parameter changes by precisely controlling the molar ratio of unsubstituted quinacridone to 2,9-dialkylquinacridone within 1:4 to 1:1, and controlling particle diameter within 30-100 nm. These parameter optimizations achieve high chroma and bluish hue while maintaining feasible production through the co-cyclization reaction in polyphosphoric acid followed by controlled heating treatment.
2Manufacturing precision
If particle diameter is not controlled, then production is easier, but inkjet ink application requires fine and uniform particles
Solution Approach 1:
The patent applies preliminary action by controlling the particle diameter during the pigmentation process itself through heating treatment at 50-150°C for 1-48 hours, rather than requiring post-production size reduction. This preliminary control of particle size during the main reaction process achieves the required 30-100 nm diameter for inkjet applications without adding complex downstream processing steps.
3Reliability
If water content is not reduced, then drying step is simpler, but pigment quality and stability are insufficient
Solution Approach 1:
The patent applies parameter changes by controlling the water content to less than 1% through the drying step after co-cyclization. This parameter control ensures pigment stability and prevents aggregation, while the drying is integrated into the existing production sequence without requiring additional complex equipment or processes.
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 method produces quinacridone solid solution pigments with controlled particle diameters and high chroma, achieving improved color performance and stability in inkjet inks, meeting market demands for bluish hues and ensuring ejection stability.
Implementation Method 1
a diarylaminoterephthalic acid and a dialkylarylaminoterephthalic acid are subjected to a co-cyclization reaction in polyphosphoric acid to obtain a water-containing crude quinacridone solid solution
Implementation Method 2
the water-containing crude quinacridone solid solution obtained in the solid solution production step is dried to reduce a water content to less than 1%
Implementation Method 3
the powdery, crude quinacridone solid solution is heated in a liquid medium that cannot dissolve the crude quinacridone solid solution
Data Source
AI summary
There is provided a technique for producing a quinacridone solid solution pigment, the technique making it possible to obtain a quinacridone solid solution pigment which produces a colored product having high chroma and a bluish hue, more preferably which has controlled particle diameters. Specifically, a method for producing a quinacridone solid solution pigment, the method including a crude quinacridone solid solution production step of subjecting a diarylaminoterepththalic acid and a dialkylarylaminoterephthalic acid to a co-cyclization reaction in polyphosphoric acid, thereby obtaining a water-containing crude quinacridone solid solution containing a solid solution of an unsubstituted quinacridone and a 2,9-dialkylquinacridone, the solid solution containing water, a drying step of drying the water-containing crude quinacridone solid solution to reduce the water content to less than 1% and obtain a powdery, crude quinacridone solid solution, and a pigmentation step of heating the powdery, crude quinacridone solid solution in a liquid medium that cannot dissolve the crude quinacridone solid solution.