Disperse Azo Dye Molecular Structure for Enhanced Fastness Properties
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Solution Overview
Problem
Current disperse azo dyes derived from a nitroaniline diazo component and an acetylaminoaniline coupling component do not consistently meet requirements for fastness properties, particularly in blue dyes, regarding light, washing, and perspiration resistance when used in dyeing hydrophobic fibre materials.
Innovation Solution
Development of disperse dyes with specific structural formulas, including diazotization and coupling processes, that yield dyes with improved fastness to light, washing, and perspiration, and their use in dyeing or printing of semi-synthetic and synthetic hydrophobic fibre materials, especially textile materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional disperse azo dyes are used, then the dyeing process is simple, but the fastness properties (light, washing, perspiration) are insufficient
Solution Approach 1:
The patent modifies the molecular structure parameters of disperse azo dyes by introducing specific substituents (acetylamino group at position 2 or 6, and electron-withdrawing groups like nitro, cyano, or halogen at positions 3 or 5) to enhance fastness properties while maintaining dyeing performance
Solution Approach 2:
The patent creates composite dye molecules by combining multiple functional groups (azo chromophore, acetylamino group, and electron-withdrawing substituents) within a single molecular structure to achieve synergistic effects that improve both fastness and color properties
2Illumination intensity
If blue dye shades are intensified, then color brilliance improves, but fastness properties deteriorate
Solution Approach 1:
The patent applies electron-withdrawing substituents at specific positions (3 or 5) on the diazo component to locally modify electron distribution in the molecule, which enhances both color brilliance and fastness properties without compromising overall performance
Solution Approach 2:
The patent optimizes the balance between color intensity and fastness by carefully selecting and positioning substituents with appropriate electronic effects, achieving blue shades with both high brilliance and excellent fastness properties
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 new dyes provide excellent fastness properties, including good lightfastness, washing fastness, and perspiration resistance, with excellent build-up in exhaust and thermosol processes and textile printing, while maintaining level color shades and resistance to rubbing, chlorine, and wetting.
Implementation Method 1
The diazotisation is carried out in a manner known per se, for example with sodium nitrite in an acidic, e.g. hydrochloric-acid-containing or sulfuric-acid-containing, aqueous medium
Implementation Method 2
coupling the diazonium compound so obtained to a coupling component of formula (3)
Data Source
AI summary
The present invention relates to disperse azo dyes of formulawhereinR1 is bromo, nitro, cyano, methyl, methoxy or trifluoromethyl;R2 is hydrogen, chloro, bromo or trifluoromethyl;R3 is hydrogen, chloro, bromo, methoxy, trifluoromethyl, nitro or cyano; andR4 is methyl, ethyl, n-propyl, 2-methoxyethyl, methoxycarbonylmethyl or 2-methoxycarbonylethyl;with the proviso that R1 is cyano in case R2 denotes chloro or bromo,to a process for the preparation of such dyes and to their use in the dyeing or printing of semi-synthetic and, especially, synthetic hydrophobic fibre materials, more especially textile materials.